NL2035501B1

NL2035501B1 - Steerable instrument with steering unit

Info

Publication number: NL2035501B1
Application number: NL2035501A
Authority: NL
Inventors: Hendrik Louis Thissen Mattheus
Original assignee: Fortimedix Assets Ii B V
Priority date: 2023-07-28
Filing date: 2023-07-28
Publication date: 2025-02-11
Also published as: WO2025026702A1

Abstract

A steerable instrument has a deﬂectable tip portion (13; 74; 75) at a distal side. A ﬁrst steering Wire (16(1); 429) is attached to the deﬂectable tip portion (13; 74, 75). The ﬁrst steering Wire (16(1); 429) is part of a tube (3; 102, 103; 121) and is separated from other parts of the tube (3; 102, 103; 121) by a ﬁrst material removal pattern such that the ﬁrst steering Wire (16(1); 429) extends from a proximal end to a distal end of the steerable instrument. The steerable instrument has a steering unit With a control tube portion (301a(i); 302a(1,3); 431) coaxially arranged with the 10 tube (3). The control tube portion (301a(i); 302a(1,3); 431) controls rotation of the ﬁrst control tube portion (301a(i); 302a(1,3)) Which causes longitudinal movement of the steering Wire (16(1); 429) in order to deﬂect the deﬂectable tip portion (13; 74; 75)) in a ﬁrst plane. |Fig. 16B|

Description

STEERABLE INSTRUMENT WITH STEERING UNIT

FIELD OF THE INVENTION

[01] The invention relates to a steerable instrument with steering unit.

BACKGROUND OF THE INVENTION

[02] Transformation of surgical interventions that require large incisions for exposing a target area into minimal invasive surgical interventions, i.e. requiring only natural orifices or small incisions for establishing access to the target area, is a well-known and ongoing process. Steerable surgical minimal invasive instruments in the field of gastroscopy, colonoscopy, endoscopy, laparoscopy, etc. are well-known in the art. These invasive instruments can comprise a steerable tube shaped device that enhances its navigation and steering capabilities. Such a steerable tube shaped device may comprise a proximal end part, a distal end part including at least one deflectable zone and a rigid or flexible intermediate part or shaft, wherein the steerable tube shaped device, at its proximal end, further comprises a steering arrangement that is adapted to deflect the distal deflectable zone relative to a central axis of the tube shaped device. The steering arrangement may be implemented by a hand held and hand operated steering device that translates arm, wrist and / or finger movements into the desired movement of the instrument’s distal part.

Alternatively, the steering arrangement may be implemented by a robotic device that translates, for example, electric motor rotation in the desired movement of the instrument’s distal part.

[03] Most of the known instruments are complex to manufacture resulting in expensive instruments. Often, the distal end of the instruments comprises a flexible zone that is composed of separate links with hinging pins, coils or flexible plastic extrusions. Steering cables are guided through holes through these links and/or through guiding tubes, eyes or hooks. Furthermore, the steering arrangement usually comprises conventional steering cables with, for instance, sub 1 mm diameters as control members, wherein the steering cables are arranged between related deflectable zones at the distal end part and the steering arrangements at the proximal end part of the tube shaped device.

[04] Steering cables are often numerous, small and floppy and a connection between the wires and the robot actuators cannot be made by an end user on site. Another and more robust means of connecting an instrument to a robot, that can easily be performed by an operator on site, is required. Therefor steerable instruments used in robotic applications have in common that between the instrument shaft and the robot an appropriate connection box is provided.

The box usually contains mechanical or electromechanical means that translate for example robot actuator motor rotation to the correct longitudinal displacement of the instrument’s steering cables. Furthermore, the box usually comprises an easy to attach connection interface to the robot. These connection boxes can be quit complex and expensive to manufacture and in most cases, this box is permanently attached to the instrument by the manufacturer.

[05] In medical applications, contamination of an instrument after it has been used to perform a surgical procedure on a patient can result in undesired post- operative complications when used on a next patient. The contamination may be due to blood, other body fluids, tissue, etc. As a consequence of the contamination, the instrument may contain germs, viruses or other biological or chemical substances that could threat the health of the next patient on which the instrument is used.

[06] One way of avoiding this contamination requires performing a thorough cleaning and sterilization of the instrument before each use. In many cases, the cleaning process is not capable of removing all contamination. Therefore, a risk of adverse effects on a patient that is treated with such an instrument still exists.

Furthermore, the cleaning process is expensive and requires appropriate infrastructure and trained people. In order to prevent the risk of contamination, there is a preference for using disposable instruments that are used a single time and are thrown away after treating one patient. But, the high costs of state of the art instruments and the attached interface box enforces the multiple re-use of these instruments to keep the instrument cost per procedure at an acceptable level. A further huge disadvantage is that not only the instrument but also the attached interface box is thrown away after a limited number of uses.

Commercially and looking from the perspective of waste management and costs thereof, this is not an optimal solution. Furthermore, because of the usually relatively large dimensions of the interface box, the packaging of such an instrument becomes quite bulky, contains a large volume of materials and occupies a significant amount of space during transport and storage, which even increases the cost and waste problem.

[07] To enable single use commercial viability of these robotic instruments and to minimize waste and transport and storage space for these instruments, one can make a steerable instrument by making hinge constructions, steering cables and other required functional parts by laser cutting these parts integrally and pre-assembled out of tube elements. Further details regarding the design and fabrication of the abovementioned steerable instrument have been described for example in WO2009/1 12060, WO2009/127236, WO2012128618,

WO20121733548, WO2014011049, WO2015084174, WO2016089202,

WO2017010883, WO2017014624, WO2017082720, WO2017213491,

WO2018067004, WO2019009710, WO2020080938, WO2020214027,

WO2020218920, WO2020218921, W02022260518, and WO2023287286.

[08] In combination with this method of building the instrument body, one could avoid an interface box by creating a coupling between the instrument steering wires directly on to the fully re-useable robot as is proposed in

NL2030160B1.

[09] NL2030160B1 describes an instrument in which a connection box is obsolete and in which the connection box functionality is fully transferred to the re-useable robot. This is enabled by the implementation of a method for directly coupling the instrument steering elements to the robot actuation output.

Attaching the instrument to the robot can easily be performed by the end user and on site, in the operating theatre.

[10] Besides instruments that are used on combination with robotic controllers, steerable instruments for minimal invasive surgery can also be used as a hand held and controlled device. Instead of the control box for attachment to a robot, these instruments usually comprise a handle that translates arm, wrist and / or finger movements into the desired movement of the instrument’ s steering cables. Also here, comparable disadvantages arise. The handle can be complex and expensive and usually is even more bulky than a robotic connection box. Also the cost per instrument usually is so high that single use is not attractive. An example of such an instrument is shown in US2015/0107396, in which an instrument is shown that comprises a permanently attached handle containing actuation means for bending the instrument distal part. Limitations and disadvantages of US2015/0107396 are as mentioned above. Furthermore, the proposed device is only capable of deflecting its distal portion in one plane.

[11] Therefor also the category of hand held instruments can benefit from the strategy of making a single use instrument body as is described in

WO2009/112060, WO2009/127236, WO2012128618, WO201217335a8,

WO2014011049, WO2015084174, WO2016089202, WO2017010883,

WO2017014624, WO2017082720, WO2017213491, WO2018067004,

WO2019009710, WO2020080938, WO2020214027, WO2020218920,

WO2020218921, WO2022260518, and WO2023287286, and combine this with a re-useable handle. Also here, an end user operable coupling between the instrument body and the handle is then required. Steerable instruments with detachable handles do exist, but the main drawback of these devices is that steering of the instrument tip is accomplished by a wrist like or ball joint section in the proximal end of the instrument body to which the steering cables are attached. The instrument is steered by moving the complete handle by wrist and arm movements. Furthermore, the proximal part of the instruments, just distal of the steering wrist, need to be held in place by a second hand or by a device like an introducer or trocar to be able to precisely steer the instrument.

Generally, the handles do not have means for actuation of individual steering cable by finger movement only, whilst the handle can be held stationary.

[12] Therefor also hand held instruments could benefit from a better solution for detachable handles in which coupling and actuation means are provided that enable steering of the instrument by finger movement only. A coupling as proposed in NL2030160B 1 could be applied, but the handle then still needs mechanical or electro-mechanical mechanisms that translate finger movements into longitudinal displacement of the coupling fingers.

[13] The current widely adapted philosophy of making the disposable part of a steerable device as simple as possible and transfer all ‘complexity’ to the reusable part of that device, which can either be a handle or a robot, was the basis for prior art like NL2030160B1 and others. ‘Complexity’ here stands for all means needed for translating motor motion (robot) or operator arm, wrist or finger movement (hand held) into the correct movement of steering wires/cables in the steerable instrument. For that reason, a detachable coupling between the disposable part and the reusable part is assumed to be needed at the 5 level of the steering wires/cables itself, which in many cases is not technically viable. The current industry standard therefore is that robotic instruments generally have a connection box attached to the instrument body and hand held steerable instruments generally have a handle permanently attached to the instrument body.

SUMMARY OF THE INVENTION

[14] It is an object of the invention to provide a steerable instrument for endoscopic and/or invasive type of applications where at least one of the above mentioned problems are solved or at least reduced.

[15] In a first aspect, this is achieved by a steerable instrument as claimed in the attached independent claim 1.

[16] In such an instrument, the ‘complexity’ is divided over the single use instrument body and the reusable handle or robot such that the main requirements for an optimal solution are addressed. Moreover, more components of the steering unit than in the prior art are simple components made in the disposable instrument itself from a few tubes. The disposable instrument is easy to manufacture and is as compact as possible and requires a minimum of interfacing parts and secondly, an easy and fail safe detachable coupling that can be operated by the end user, on site, is established. The coupling may be to a hand-held control unit or to a robotic control unit.

[17] A permanently attached connection box or handle can be omitted by transferring al required mechanisms needed for translating robot controller output or hand, wrist or finger movement into the desired distal tip movement, into the instrument body itself. Furthermore, production cost of such an instrument can potentially be so low that single use of these instruments is commercially viable. Another advantage is that the instrument dimensions are much smaller that the currently available instruments, which has an advantageous impact on transport and storage volume and the volume of packaging and instrument waste.

[18] Advantageous embodiments are claimed in dependent claims.

[19] A second aspect of the invention relates to compensating path length differences which may occur between adjacent steering wires, e.g., due to bending of the instrument body when the steerable instrument is inserted in a curved channel, e.g, intestines, blood vessels or bronchial tubes in a living being.

[20] In instrument for this second aspect is claimed in independent claim 24 and advantageous embodiments are claimed in dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[21] Further features and advantages of the invention will become apparent from the description of the invention by way of non-limiting and non-exclusive embodiments. These embodiments are not to be construed as limiting the scope of protection. The person skilled in the art will realize that other alternatives and equivalent embodiments of the invention can be conceived and reduced to practice without departing from the scope of the present invention. Moreover, separate features of different embodiments can be combined, even if not explicitly shown in the drawings or explained in the specification, unless such combination is physically impossible. The scope of the present invention is only limited by the claims and their technical equivalents. Embodiments of the invention will be described with reference to the figures of the accompanying drawings, in which like or same reference symbols denote like, same or corresponding parts, and in which:

[22] Figure 1 shows a schematic cross sectional view of a distal section of a prior art invasive instrument assembly.

[23] Figure 2 shows a schematic overview of distal portions of three prior art cylindrical elements from which the distal portion of Figure 1 may be manufactured.

[24] Figure 3a shows a distal portion of a prior art intermediate cylindrical element of the instrument of Figures 1 and 2.

[25] Figure 3b shows a distal portion of an alternative example of a prior art intermediate cylindrical element of such an instrument.

[26] Figure 4 shows a distal portion of an example of a prior art intermediate cylindrical element and an inner cylindrical element inserted in the intermediate cylindrical element.

[27] Figure 5 shows an outside view of a distal section of a prior art steerable invasive instrument assembly having two steerable bendable distal end portions and two proximal flexible control portions.

[28] Figure 6 shows an enlarged view of the distal tip of the instrument shown in Figure 5.

[29] Figure 7A shows a cross section view through the invasive instrument shown in Figure 5.

[30] Figure 7B shows a distal end of an inner tube and intermediate tube of an alternative embodiment of a double bendable instrument in 3D view.

[31] Figures 8 and 9 show examples of how the invasive instrument of

Figures 5 and 7 can bend.

[32] Figures 10-14 show some basic technologies that can be used to move one or more steering wires in the longitudinal direction.

[33] Figures 15, 16A, 16B show arrangements that can be used to move one steering wire in the longitudinal direction by a tangentially rotatable tube- shaped element.

[34] Figures 17, 18A, 18B show arrangements that can be used to move two steering wires in opposite longitudinal directions by a tangentially rotatable tube-shaped element.

[35] Figures 19, 20A, 20B show arrangements that can be used to move four steering wires in the longitudinal direction by two tangentially rotatable tube- shaped element.

[36] Figures 21, 22A, 22B show arrangements that can be used to move two steering wires in opposite longitudinal directions by a tangentially rotatable tube-shaped element which is itself driven by a longitudinally shiftable element.

[37] Figures 23, 24, 25A, 25B, 26 show arrangements that can be used to move four steering wires in the longitudinal direction by two tangentially rotatable tube-shaped elements which are both driven by a tangentially rotatable and longitudinally shiftable element.

[38] Figures 27, 28 A-28D show arrangements that can be used to move four steering wires in the longitudinal direction by two tangentially rotatable tube-

shaped elements which are both driven by an alternative tangentially rotatable and longitudinally shiftable element.

[39] Figures 29A-29C show a gear arrangement.

[40] Figures 30A, 30B, 31 show arrangements for longitudinally moving one or more sets of two adjacent longitudinal elements, like steering wires, by longitudinally moving a single longitudinal control element of which the longitudinal movement is controlled by one or more tangentially rotatable tube- shaped elements.

[41] Figures 32A to 35 show some further gear arrangements.

[42] Figures 36A-36C show an example of a coupling of a disposable instrument with two rotating tubes.

[43] Figures 37 and 38, respectively, show a rotatable or slidable tubular interface of an instrument with spur gear teeth and worm drive gear teeth, respectively.

DETAILED DESCRIPTION OF EMBODIMENTS

[44] For the purpose of the present document, the terms cylindrical element and tube may be used interchangeably, i.e., like the term tube a cylindrical element also refers to a physical entity. The invention will be explained with reference to steering wires which are cut from such cylindrical elements and are operative as push and/or pull steering wires to transfer longitudinal movement of the steering wires at the proximal end of the instrument to the distal end to thereby control bending of one or more flexible distal end portions. They have a strip like shape and, because they are cut from a tube, have a curved rectangular, cross section seen in the tangential direction of the steerable instrument.

[45] Figures 1, 2, 3a, and 3b show distal portions of instruments known from

WO2009/112060. They are explained in detail because the present invention can be applied in this type of instruments.

[46] Figure 1 shows a longitudinal cross-section of a distal section of a prior art steerable instrument 1 comprising three co-axially arranged cylindrical elements, 1.e. inner cylindrical element 2, intermediate cylindrical element 3 and outer cylindrical element 4. Suitable materials to be used for making the cylindrical elements 2, 3, and 4 include stainless steel, cobalt-chromium alloys, shape memory alloy such as Nitinol®, plastic, polymer, composites or other materials that can be shaped by material removal processes like laser cutting or EDM. Alternatively, the cylindrical elements can be made by a 3D printing process or other known material deposition processes.

[47] The inner cylindrical element 2 comprises a first rigid end part 5, which is located at a deflectable distal end part 13 of the instrument, a first flexible part 6, and an intermediate rigid part 7 located at an intermediate part 12 of the instrument.

[48] The outer cylindrical element 4 also comprises a first rigid end part 17, a first flexible part 18, and an intermediate rigid part 19. The lengths of the parts 5, 6, and 7, respectively, of the cylindrical element 2 and the parts 17, 18, and 19, respectively, of the cylindrical element 4 are, preferably, substantially the same so that when the inner cylindrical element 2 is inserted into the outer cylindrical element 4, these different respective parts are longitudinally aligned with each other.

[49] The intermediate cylindrical element 3 also has a rigid end part 10 which in the assembled condition is located between the corresponding rigid parts 5 and 17 of the two other cylindrical elements 2, 4. An intermediate part 14 of the intermediate cylindrical element 3 comprises one or more separate steering wires 16 which can have different forms and shapes as will be explained below. They are made from the cylindrical element 3 themselves and have the form of a longitudinal strip. In figure 2, three such steering wires 16 are shown. After assembly of the three cylindrical elements 2, 3 and 4 whereby the element 2 is inserted in the element 3 and the two combined elements 2, 3 are inserted into the element 4 (any other order is possible), at least the first rigid end part 5 of the inner cylindrical element 2, the first rigid end part 10 of the intermediate cylindrical element 3 and the first rigid end part 17 of the outer cylindrical element 4 at the distal end of the instrument are attached to each other, e.g., by means of glue or one or more (laser) welding spots.

[50] In the embodiment shown in figure 2 the intermediate part 14 of intermediate cylindrical element 3 comprises a number of steering wires 16 with a uniform cross-section so that the intermediate part 14 has the general shape and form as shown in the unrolled condition of the intermediate cylindrical element 3 in figure 3a. From figure 2 it also becomes clear that the intermediate part 14 is formed by a number of over the circumference of the intermediate cylindrical part 3, possibly equally, spaced parallel steering wires 16. Advantageously, the number of steering wires 16 is at least three, so that the instrument becomes fully controllable in any direction, but any higher number is possible as well. The number of steering wires 16 may, e.g., be four or eight.

[51] It is observed that the steering wires 16 do not need to have a uniform cross section along their entire length. They may have a varying width along their length, possibly such that at one or more locations adjacent steering wires 16 are only separated by a small slot resulting from the laser cutting in the cylindrical element 3. These wider portions of the steering wires, then, operate as spacers to prevent adjacent steering wires 16 from buckling in a tangential direction in a pushed state.

Spacers may, alternatively, be implemented in other ways.

[52] An embodiment with spacers is shown in figure 3b which shows distal portions of two adjacent steering wires 16 in an unrolled condition. In the embodiment shown in figure 3b each steering wire 16 comprises portions 64 and 62, co-existing with the first flexible part 6, 18 and the intermediate rigid part 7, 19, respectively. In the portion 62 coinciding with the intermediate rigid portion, each pair of adjacent steering wires 16 is almost touching each other in the tangential direction so that in fact only a narrow slot is present there between just sufficient to allow independent movement of each steering wire. The slot results from the manufacturing process and its width is, e.g., caused by the diameter of a laser beam cutting the slot.

[53] In portion 61 each steering wire 16 consists of a relatively small and flexible part 64 as seen in circumferential direction, so that there is a substantial gap between each pair of adjacent flexible parts, and flexible part 64 is provided with a number of spacers 66, extending in the tangential direction and almost bridging completely the gap to the adjacent flexible part 64. Because of these spacers 66 the tendency of the steering wires 16 in the flexible portions of the instrument to shift in tangential direction is suppressed and tangential direction control is improved.

The exact shape of these spacers 66 is not very critical, provided they do not compromise flexibility of flexible part 64. One or more spacers 66 are attached to flexible part 64 and form an integral part with the flexible part 64 and may result from a suitable laser cutting process too. They extend to an adjacent flexible part 64 of an adjacent steering wire 16.

[54] In the embodiment shown in figure 3b the spacers 66 are extending towards one tangential direction as seen from the flexible part 64 to which they are attached.

It is however also possible to have these spacers 66 extending to both circumferential directions starting from one flexible part 64. By using this it is either possible to have alternating types of flexible parts 64 as seen along the tangential direction, wherein a first type is provided at both sides with spacers 66 extending until the next flexible part, and a second intermediate set of flexible parts 64, without spacers 66. Otherwise it is possible to have flexible parts with cams at both sides, where as seen along the longitudinal direction of the instrument the cams originating from one flexible part are alternating with spacers originating from the adjacent flexible parts. It is obvious that numerous alternatives are available.

[55] The production of such an intermediate part is most conveniently done by injection moulding or plating techniques or starting from a cylindrical tube with the desired inner and outer diameters and removing parts of the wall of the cylindrical tube required e.g. by laser or water cutting to end up with the desired shape of the intermediate cylindrical element 3. However, alternatively, any 3D printing method can be used.

[56] The removal of material can be done by means of different techniques such as laser cutting, photochemical etching, deep pressing, conventional chipping techniques such as drilling or milling, high pressure water jet cutting systems or any suitable material removing process available. Preferably, laser cutting is used as this allows for a very accurate and clean removal of material under reasonable economic conditions. The above mentioned processes are convenient ways as the cylindrical element 3 can be made so to say in one process, without requiring additional steps for connecting the different parts of the intermediate cylindrical element as required in the conventional instruments, where conventional steering cables must be connected in some way to the end parts.

[57] The same type of technology can be used for producing the inner and outer cylindrical elements 2 and 4 with their respective flexible parts 6, 18. These flexible parts 6, 18 can be manufactured as hinges resulting from cutting out any desired pattern from the cylindrical elements, e.g., by using any of the methods described in

European patent application 08 004 373.0 filed on 10.03.2008, page 5, lines 15-26, but any other suitable process can be used to make flexible portions.

[58] It is observed that the instrument portions shown in figures 4-9 are known from prior art WO2020/214027. Also in these instruments the present invention can be applied.

[59] Figure 4 shows an exemplary embodiment of longitudinal (steering) elements 16 that have been obtained after providing longitudinal slots 70 to the wall of the intermediate cylindrical element 3. Here, steering wires 16 are, at least in part, spiraling about a longitudinal axis of the instrument such that an end portion of a respective steering wire 16 at the proximal portion of the instrument is arranged at another angular orientation about the longitudinal axis than an end portion of the same steering wire 16 at the distal portion of the instrument. Were the steering wires 16 arranged in a linear orientation, than a bending of the instrument at the proximal portion in a certain plane would result in a bending of the instrument at the distal portion in the same plane but in a 180 degrees opposite direction. This spiral construction of the steering wires 16 allows for the effect that bending of the instrument at the proximal portion in a certain plane may result in a bending of the instrument at the distal portion in another plane, or in the same plane in the same direction. A preferred spiral construction may be such that the end portion of a respective steering wire 16 at the proximal portion of the instrument is arranged at an angularly shifted orientation of 180 degrees about the longitudinal axis relative to the end portion of the same steering wire 16 at the distal portion of the instrument. However, e.g. any other angularly shifted orientation, e.g. 90 degrees, is within the scope of this document. The slots 70 are dimensioned such that movement of a steering wire is guided by adjacent steering wires when provided in place in a steerable instrument. However, especially at the flexible zone 13 of the instrument, the width of steering wires 16 may be less to provide the instrument with the required flexibility / bendability at this location.

[60] Figure 5 provides a detailed perspective view of the distal portion of an embodiment of an elongated tubular body 76 of a steerable instrument which has two deflectable distal deflectable zones 74, 75. Figure 5 shows that the elongated tubular body 76 comprises a number of co-axially arranged layers or cylindrical elements including an outer cylindrical element 104 that ends after a first distal flexible zone 74 at the distal end portion 13. The distal end portion 13 of the outer cylindrical element 104 is fixedly attached to a cylindrical element 103 located inside of and adjacent to the outer cylindrical element 104, e.g. by means of (laser) welding at welding spots 100. However, any other suitable attachment method can be used, including any mechanical snap fit connection or gluing by a suitable glue.

[61] Figure 6 provides a more detailed view of the distal end part 13 and shows that, in this embodiment, it includes three co-axially arranged layers or cylindrical elements, i.e, an inner cylindrical element 101, a first intermediate cylindrical element 102 and a second intermediate cylindrical element 103. The distal ends of inner cylindrical element 101, first intermediate cylindrical element 102 and second intermediate cylindrical element 103 are all three fixedly attached to one another.

This may be done by means of (laser) welding at welding spots 100. However, any other suitable attachment method can be used, including any mechanical snap fit connection or gluing by a suitable glue. The points of attachment may be at the end edges of inner cylindrical element 101, first intermediate cylindrical element 102 and second intermediate cylindrical element 103, as shown in the figures. However, these points of attachment may also be located some distance away from these edges, be it, preferably, between the end edges and the locations of the flexible zone 75.

[62] It will be clear to the skilled person that the elongated tubular body 76 as shown in figure 5 comprises four cylindrical elements in total. The elongated tubular body 76 according to the embodiment shown in figure 5 comprises two intermediate cylindrical elements 102 and 103 in which the steering members of the steering arrangement may be arranged. However, extra or less cylindrical elements may be provided if desired.

[63] An exemplary actual arrangement of the steering members is shown in figure 7A, which provides a schematic longitudinal cross-sectional view of the exemplary embodiment of the elongated tubular body 76 as shown in figure 5.

[64] Flexible zones 74, and 75 are, in this embodiment, implemented by providing the respective cylindrical elements with slits 74a, and 75a, respectively.

Such slits 74a, and 75a may be arranged in any suitable pattern such that the flexible zones 74, and 75 have a desired flexibility in the longitudinal and tangential direction in accordance with a desired design.

[65] Figure 7A shows a longitudinal cross section of the four layers or cylindrical elements mentioned above, i.e. the inner cylindrical element 101, the first intermediate cylindrical element 102, the second intermediate cylindrical element 103, and the outer cylindrical element 104.

[66] The inner cylindrical element 101, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 111, which is arranged at the distal end part 13 of the steerable instrument 10, a first flexible portion 112, a first intermediate rigid portion 113, a second flexible portion 114, and a second intermediate rigid portion 115.

[67] The first intermediate cylindrical element 102, as seen along its length from the distal end to the proximal end of the instrument, comprises a rigid ring 121, a first flexible portion 122, a first intermediate rigid portion 123, a second flexible portion 124, and a second intermediate rigid portion 125. The portions 122, 123, 124, and 125 together form a steering wire 16(1) that can be moved in the longitudinal direction like a wire. The longitudinal dimensions of the rigid ring 121, the first flexible portion 122, the first intermediate rigid portion 123, the second flexible portion 124, and the second intermediate rigid portion 125 of the first intermediate element 102, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, and the second intermediate rigid portion 115 of the inner cylindrical element 101, respectively, and are coinciding with these portions as well. In this description “approximately equal” means that respective same dimensions are equal within a margin of less than 10%, preferably less than 5%.

[68] Similarly, the first intermediate cylindrical element 102 comprises one or more other steering wires 16(2).

[69] The second intermediate cylindrical element 103, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 131, a first flexible portion 132, a second rigid ring 133, a second flexible portion 134, and a first intermediate rigid portion 135. The portions 133, 134, and 135 and 136 together form a steering wire 130(1) that can be moved in the longitudinal direction like a wire. The longitudinal dimensions of the first rigid ring 131, the first flexible portion 132 together with the second rigid ring 133 and the second flexible portion 134 and the first intermediate rigid portion 135 of the second intermediate cylinder 103, respectively, are aligned with, and preferably approximately equal to the longitudinal dimensions of the rigid ring 111, the first flexible portion 112, the first intermediate rigid portion 113, the second flexible portion 114, and the second intermediate rigid portion 115 of the first intermediate element 102, respectively, and are coinciding with these portions as well.

[70] Similarly, the second intermediate cylindrical element 103 comprises one or more other steering wires of which one is shown with reference number 130(2).

[71] The outer cylindrical element 104, as seen along its length from the distal end to the proximal end of the instrument, comprises a first rigid ring 141, a first flexible portion 142, and a first intermediate rigid portion 143. The longitudinal dimensions of the first flexible portion 142 and the of the outer cylindrical element 104, respectively, are aligned with, and preferably approximately equal to the longitudinal dimension of the second flexible portion 134 and the first intermediate rigid portion 135 of the second intermediate element 103, respectively, and are coinciding with these portions as well. The rigid ring 141 may have approximately the same length as the rigid ring 133 and is fixedly attached thereto, e.g. by spot welding or gluing. The rigid rings 111, 121 and 131 are attached to each other, e.g., by spot welding or gluing. This may be done at the end edges thereof but also at a distance of these end edges.

[72] The inner and outer diameters of the cylindrical elements 101, 102, 103, and 104 are chosen in such a way at a same location along the elongated tubular body 76 that the outer diameter of inner cylindrical element 101 is slightly less than the inner diameter of the first intermediate cylindrical element 102, the outer diameter of the first intermediate cylindrical element 102 is slightly less than the inner diameter of the second intermediate cylindrical element 103 and the outer diameter of the second intermediate cylindrical element 103 is slightly less than the inner diameter of the outer cylindrical element 104, in such a way that a sliding movement of the adjacent cylindrical elements with respect to each other is possible. The dimensioning should be such that a sliding fit is provided between adjacent elements. A clearance between adjacent elements may generally be in the order of 0.02 to 0.1 mm, but depends on the specific application and material used.

The clearance may be smaller than a wall thickness of the steering wires to prevent an overlapping configuration thereof. Restricting the clearance to about 30% to 40% of the wall thickness of the steering wires is generally sufficient.

[73] The use of the construction as described above allows the steerable instrument 10 to be used for double bending. The working principle of this construction will be explained with respect to the examples shown in figures 8 and 9.

[74] For the sake of convenience, as shown in figures 7A, 8 and 9, the different portions of the cylindrical elements 101, 102, 103, and 104 have been grouped into zones 151 - 155 that are defined as follows. Zone 151 comprises the rigid rings 111, 121, and 131. Zone 152 comprises the portions 112, 122, and 132. Zone 153 comprises the rigid rings 133 and 141 and the portions 113 and 123. Zone 154 comprises the portions 114, 124, 134 and 142. Zone 155 comprises the portions 115, 125, 135 and 143.

[75] By pushing / pulling steering wires 130(1), 130(2) in the longitudinal direction of the instrument, one side of the attached rigid rings 133/141 can be moved either in the proximal or distal direction of the instrument, whereas at the opposing tangential side of the instrument these attached rigid rings 133/141 can be moved in the opposite direction, resulting in a deflection of the instrument of deflectable zone 154, as shown in figure 8.

[76] When three or more steering wires per set 130) ((= 1, 2,3, ...]), preferably equally tangentially spaced, are applied deflectable zone 154 can be deflected in any desired direction.

[77] By pushing / pulling steering wires 16(1), 16(2) in the longitudinal direction of the instrument, one side of the attached rigid rings 121/131 can be moved either in the proximal or distal direction of the instrument, whereas at the opposing tangential side of the instrument these attached rigid rings 121/131 can be moved in the opposite direction, resulting in a deflection of the instrument of deflectable zone 154, as shown in figure 8.

[78] When three or more steering wires per set 16(1), preferably equally tangentially spaced, are applied deflectable zone 152 can be deflected in any desired direction.

[79] Due to the fact that zones 152 and 154 are deflectable independently with respect to each other, it 1s possible to give the distal end part 13 of the steerable instrument a position and longitudinal axis direction that are independent from each other. In particular the distal end part 13 can assume an advantageous S-like shape.

The skilled person will appreciate that the capability to independently deflect zones 152 and 154 with respect to each other, significantly enhances the manoeuvrability of the distal end part 13 and therefore of the steerable instrument as a whole.

[80] Obviously, it is possible to vary the lengths of the flexible portions shown in figures 7A to 9 as to accommodate specific requirements with regard to bending radii and total lengths of the distal end part 13 and the proximal end part 11 of the steerable instrument.

[81] In the shown embodiment, the steering wires comprise one or more sets of steering wires that form integral parts of the one or more intermediate cylindrical elements 102, 103. Preferably, the steering wires comprise remaining parts of the wall of an intermediate cylindrical element 102, 103 after the wall of the intermediate cylindrical element 102, 103 has been provided with longitudinal slits that define the remaining steering wires.

[82] Whereas in figures 7A, 8, 9 an embodiment is shown in which steering wires 16(1), 16(2) for deflecting the most distal deflectable zone 75 are made in another tube than steering wires 130(1), 130(2) for deflecting deflectable zone 74, all such steering wires can be made in one single tube as shown in figure 7B, in which reference numbers 130 are substituted by reference numbers 16. Figure 7B shows four steering wires 16(1) — 16(4) of a total of eight steering wires all made in tube 102. Figure 7B shows how rigid rings 111 and 121 are attached to another at one or more attachment points 170, e.g. by (laser) welding or gluing, etc. It also shows that steering wires 16(1) and 16(3) are attached to rigid ring 121 (the same is true for steering wires 16(5) and 16(7) but they are not visible in figure 7B). The distal ends of steering wires 16(2), 16(4) (as well as 16(6) and 16(8)) are attached to intermediate rigid portion 113 at attachment points 172, e.g. by (laser) welding or gluing, etc.

[83] By pulling/pushing steering wires 16(1), 16(3), 16(5), 16(7) one can deflect flexible portion 112 and by pulling/pushing steering wires 16(2), 16(4), 16(6), 16(8) one can deflect flexible portion 114, as one will understand based on the above explanations.

[84] Steering unit

[85] The following describes embodiments of instruments, hand held and robotic actuators, and coupling methods that improve cost effectiveness and enable single use of instruments and therefor reduction of the occurrence of post operative complications associated with re-use of instruments. Furthermore, the volume of the disposable instruments is significantly reduced which has a desirable effect on storage and shipment volume and the volume of waste.

[86] The following embodiments show instruments and handles and robot interfaces in which the ‘complexity’ is divided over the single use instrument and the reusable handle or robot such that the main requirements for an optimal solution are addressed. Firstly, the disposable instrument is easy to manufacture and is as compact as possible and requires a minimum of interfacing parts and secondly, an easy and fail safe detachable coupling that can be operated by the end user, on site, is established.

[87] An instrument can be manufactured as proposed in WO2009/1 12060,

WO2009/127236, WO2012128618, W0O201217335a8, WQ2014011049,

WO2015084174, WO2016089202, WO2017010883, WO2017014624,

WO2017082720, WO2017213491, WO2018067004, WO2019009710,

WO2020080938, WO2020214027, WO2020218920, WO2020218921,

WO2022260518, and WO2023287286. These applications propose an instrument in which the required parts and features are manufactured by laser cutting the parts out of the walls of one or more tubes and leave them in a pre-assembled state. The only additional manufacturing step is to slide a number of tubes into each other and attach the layers of tubes to each other at the required locations. Once one has this method in place it is very easy and almost without additional cost, to also laser cut additional parts in the same layers of tubes.

[88] For example, WO2022260518 shows mechanisms that are used for length compensation of longitudinal members in the instrument body, for preventing that the instrument distal tip is actuated (bent) when a flexible instrument body is guided through a curved channel. WO2022260518 describes the use of tube parts, containing slots and sliding members for that purpose. As will be explained hereinafter, one can also use slots and sliding members for direct or indirect actuation of steering wires and/or other longitudinal control elements for other purposes in a steerable instrument.

[89] US2015/0107396 shows that a steering wire can be actuated by a groove, but this application only shows a conventional solution, in which the instrument and the handle are assembled from many individual parts and in which the handle is permanently attached to the instrument body. US2015/0107396 also only shows actuation elements, containing the grooves for steering wire actuation, that have a rotation axis that intersects with the longitudinal axis of the instrument body.

Furthermore, US2015/0107396 is limited to an instrument of which the distal part can only be bent in two directions in one bending plane.

[90] The following describes examples of solutions in which the permanent attachment of a hand held handle or a connection box can be avoided, by making the coupling between individual steering wires to an actuation means such that it can be done by an end user on site.

[91] Figure 10 shows an embodiment of an instrument having three — which in practise can be more - coaxial tubes, i.e, inner tube 2, an intermediate tube in which steering wires 16(1) are made, and an outer tube 203. The instrument has a centre axis 229. Each proximal end portion of steering wire 16(1) is provided with one or more pins 221(1) radially extending from the instrument through a longitudinal slot 205(1) in outer tube 203. The one or more pins 221(1) are fixed to steering wire 16(i). Each such pin 221(1) can be connected or attached to a suitable driving component in order to move the individual steering wires 16(1) to deflect the deflectable tip portion of the instrument. The driving component may be manually controlled or controlled by a robotic device.

[92] Figure 11 shows an embodiment of a steering unit of an instrument provided with four steering wires 16(1), though any other suitable number may be used instead. Outer tube 203 is provided with four longitudinal slots 205(1), each one tangentially aligned with one steering wire. However, these four different longitudinal slots 205(1) are longitudinally off-set relative to one another. Per longitudinal slot 205(1) a ring 223(1) is provided with an inner diameter slightly larger than an outside diameter of outer tube 203 such that ring 223(1) can axially slide along outer tube 203. Moreover, each ring 223(1) is attached to an associated steering wire 16(1) via longitudinal slot 205(1), e.g., by means of a pin-shaped component like pin 221(i) shown in figure 10. Each ring 223(i) has a radially extending pin 225(1). Each such ring 223(1) or pin 225(1) can be connected or attached to a suitable driving component in order to move the individual steering wires 16(1) to deflect the deflectable tip portion of the instrument. The driving component may be manually controlled or controlled by a robotic device.

[93] Figure 12 shows a variant to the embodiment of the steering unit of figure 11. Here, rings 223(1) with extending pins 225(i) are substituted by rings 227(i) with two radially extending flanges 228(1) per ring 227(1). The two flanges 228(1) are arranged at a predetermined longitudinal distance from one another such that together with ring 227(i) they define a circumferential groove.

Again outer tube 203 is provided with four — or any other suitable number of - longitudinal slots 205(1), each one tangentially aligned with one steering wire 16(1), which longitudinal slots 205(1) are longitudinally off-set relative to one another. Each ring 227(1) has an inner diameter slightly larger than the outside diameter of tube 203 such that ring 227(1) can slide along outer tube 203.

Moreover, each ring 227(1) is attached to an associated steering wire 16(1) via longitudinal slot 205(1), e.g., by means of a pin shaped component like pin 221(i) shown in figure 10 or another means of attachment like welding or bolts/screws.

[94] To allow coupling to a controller, such a controller may be provided with sliders configured to be inserted into the grooves defined by rings 227(1) and flanges 228(1) such that any longitudinal movement of the sliders inside the controller results in a longitudinal movement of the steering wires 16(1). The controller may have as many sliders as there are steering wires 16(1) to allow independent control of the steering wires 16(1). Such circumferential grooves ease alignment between each sliders and an associated steering wire 16(1) because only longitudinal alignment is required. The tangential alignment is, in this embodiment, taken care of by the groove defined by ring 227(1) and flanges 228(1). Moreover, once coupled to a controller, the instrument can be freely rotated relative to the controller because the sliders will stay in their associated groove defined by ring 227(1) and flanges 228(1).

[95] Figures 13A and 13B show an embodiment of a steering unit with rings

231(i) having a screw thread 233(i) inside. Figures 13A and 13B show only one such ring 231(1), however, there will be one ring 23 1(i) per steering wire 16(1).

Outer tube 203 is provided with a screw thread 234(1) per steering wire 16(1), longitudinally aligned with longitudinal slot 205(1). Screw thread 233(i) of each ring 231(1) is screwed on screw thread 234(1) on outer tube 203. A pin 221(1) is attached to steering wire 16(i), which pin 221(i) extends through longitudinal slot 205(1) into a circumferential groove 232(i) inside ring 23 1(1). A pin 236(1) is provided on the outer surface of ring 231(1). Figure 13B is a cross sectional view through a plane through a centre line XII through longitudinal slot 205(1) and centre axis 229.

[96] Rotating ring 23 1(i) about outer tube 203 causes ring 23 1(i) to move in the longitudinal direction of instrument I. Then, groove 232(1) rotates about pin 221(i) causing pin 221(1) and thus steering wire 16(i) to also move in the longitudinal direction of the instrument. A controller is implemented to be connected to pin 236(1) such that it is configured to rotate ring 231(i) to move steering wire 16(1) in its longitudinal direction.

[97] As an alternative to pin 236(i) the outside surface of ring 231(1) may be provided with a tooth shaped structure configured to cooperate with a suitable drive wheel inside a a controller, cf. figure 37. Also, as a further alternative, a worm gear construction may be used to drive rotation of ring 23 1(1), cf. figure 38.

[98] Figure 14 shows a further alternative of a possible coupling mechanism between the steering wires 16(1) and a controller. Here, steering wires 16(1) are provided with a set of one or more consecutive openings 235(1). Instead of openings 235(1) grooves or teeth like structures may be used, for example, a involute geared cam might be used with a corresponding involute geared wheel.

For each steering wire 16(1) the controller is provided with a gear 237(1).

Coupling of the instrument can be accomplished by having the gears 237(1) in a correct fixed radial position to engage with the openings 235(1) or the toothed cam on the end of the steering wire 16(1). When one de-couples the gears 237(1) from the drive motor such that they can rotate freely, for example with a mechanical or electro mechanical clutch, one can insert the instrument until the gears 237(i) and steering wire ends are fully engaged. At that moment the gear clutch can be engaged and the gears can be driven by the actuator motor. One could also choose to have the gears attached to a slider with a preloaded radial force, with which the gears can be opened and closed radially. Engaging the teeth of the gears and the steering wires 16(i) can be accomplished by rotating the gears till they engage. In the coupled state between the instrument and the controller every gear 237(i) is arranged and configured to cooperate with the set of one or more consecutive openings 235(1) of steering wire 16(i). Longitudinal movement of steering wires 16(1) can be controlled on an individual basis.

[99] The previous examples of figures 10-14 show simple solutions for attachment of individual steering wires with easy to couple features with which individual steering wires can be coupled to actuation means, like for example robot actuation with linear or rotating motors. Disadvantage of these solutions may be that they require individually manufactured and assembled parts. Furthermore, each individual steering wire coupling means has to be actuated by an individual actuation means in the robot or the hand held handle.

[100] Other, alternative solutions that require less individually manufactured parts and less actuator inputs are presented below. Moreover, these parts can all be manufactured from one or more tubes by providing these tubes with one or more suitable material removal patterns.

[101] One alternative method to actuate a single steering wire 16(1) is shown schematically in figure 15. A sliding member 301(1) 1s configured in the steering unit such that it can only be moved up and down. Sliding member 301(1) has a slit- shaped opening 303(1) and the steering wire 16(1) is provided with a pin 305(1) accommodated in slit-shaped opening 303(1). Slit-shaped opening 303(1) is arranged at an angle a to longitudinal direction of steering wire 16(1) such that 0 < a < 90 degrees. When sliding member 301(1) is moved downward as indicated with an arrow F1, steering wire 16(1) moves to the right, as indicated with an arrow F2, in the direction of the longitudinal axis of the instrument. When sliding member 301 is moved upward, steering wire 16(1) moves to the left.

[102] Figures 16A and 16B show an embodiment of how the steering unit of figure 15 can be incorporated in the instrument as a very easy to make and compact solution, assuming one practices manufacturing methods as described in

WO2009/112060, WO2009/127236, WO2012128618, WO2012173478,

WO2014011049, WO2015084174, WO2016089202, WO2017010883,

WO2017014624, WO2017082720, WO2017213491, WO2018067004,

WO2019009710, WO2020080938, WO2020214027, WO2020218920,

WO2020218921, WO2022260518, and WO2023287286. The embodiment of figures 16A, 16B can be made by making suitable material removal patterns in four tubes. In figures 16A, 16B, all components with a reference number with an affix “a” have the same function as the component with the same reference number without affix “a” in figure 15.

[103] The intermediate tube has, e.g., four steering wires 16(1) and the mechanism of figure 15 is shown to be applied to one of them. Outer tube 203 is provided with longitudinal slots 309(1} - one for each steering wire 16(i) — which are tangentially aligned with respective steering wires 16(1). A sliding notch 307(i) 1s provided in longitudinal slot 309(1). Sliding notch 307(i) is attached to steering wire 16(1) and can move freely in the longitudinal direction of longitudinal slot 309(1). Le, sliding notch 307(i) is guided in the longitudinal direction by longitudinal slot 309(1) and can only move in the desired steering wire direction.

[104] Only one additional tube needs to be added about outer tube 203 to complete the steering mechanism. A distal ring 321 made from this additional tube is attached to outer tube 203 at a distal location from longitudinal slot 309(1), and a proximal ring 323 is attached to outer tube 203 at a proximal location from longitudinal slot 309(1).

[105] As shown in figure 16B, the additional tube includes a control tube portion 301a(i) containing a helical slot 303a(1) and a sliding notch 305a(1) inside helical slot 303a(i). Control tube portion 301a(i) can rotate about outer tube 203 between distal ring 321 and proximal ring 323 but cannot move in the longitudinal direction between distal ring 321 and proximal ring 323 — apart from some possible play resulting from the manufacturing process. Sliding notch 305a(i) is attached to sliding notch 307(1) in outer tube 203, such that also sliding notch 305a(1) is attached to steering wire 16(1). When control tube portion 301a(i) is rotated around the coaxially arranged instrument, helical slot 303a(i) will actuate both sliding notches 307(1) and 305a(i) in a longitudinal direction. In this way, a simple, compact and easy to manufacture solution is created for attaching individual steering wires to a simple to couple element that can be rotated by for example an electric actuation motor in a robot arm directly. The mechanism does not need to be manufactured as separate parts that require individual assembly, but now it can be, for example, (laser) cut integrally and pre-assembled in some tubes, as is, e.g., described in WO2016089202. Methods of how to establish the connection between the rotatable control tube portion 301a(i) and such a motor, or a rotation actuation element in a hand held handle will be described further down in the present document.

[106] For each steering wire 16(i) a separate steering mechanism including rings 321, 323 and control tube portion 301a(i) can be provided in order to provide separate steering control for all steering wires 16(1). However, control tube portion 301a(1) can be arranged to control longitudinal movement of more than one steering wire 16(1). This is, e.g., possible because in practise the instrument may be designed such that each steering wire 16(i) has an opposite steering wire, i.e., at a 180 degrees tangentially rotated location in the instrument. In such a configuration, two opposite steering wires 16(1) when they are operated to deflect the deflectable tip move along identical distances be it in opposite longitudinal directions.

[107] If one applies the principle of figures 16A, 16B one can also envision an embodiment as shown in figure 17. In figure 17 the same reference numbers as used in figure 15 refer to the same components. In addition to figure 15, figure 17 shows two steering wires 16(1), 16(3). It is assumed that steering wire 16(3) is located at a 180 degrees tangentially rotated location relative to steering wire 16(1). The steering unit contains one single sliding member 302(1,3) with slit-shaped opening 303(1) for steering wire 16(1) and an extra slit-shaped opening 303(3) for steering wire 16(3). A pin 305(3) is attached to steering wire 16(3) and accommodated in slit-shaped opening 303(3). Slit-shaped opening 303(3) is arranged at an angle 3 relative to its longitudinal axis. In most practical cases q = 3. When one now moves sliding member 302(1,3) down, as indicated with arrow F 1, steering wire 16(1) will move in the right direction, as indicated with arrow F2, and steering wire 16(3) will move in the left direction, as indicated with arrow F3. If a = B, steering wires 16(1), 16(3) will move along the same length be it in opposite directions such that one of them is generating a pulling force and the other one is developing a pushing force, thus causing the tip to deflect. The two steering wires 16(1), 16(3) are actuated simultaneously by one control element.

[108] Figures 18A, 18B show an implementation of the steering unit of figure 17 in an instrument manufactured from some tubes and in which two steering wires can move the instrument tip in two directions, in one plane, when the slots are configured such that they move the two actuated steering wires in opposite directions. Of course, the slots can be shaped such that one can establish any desired actuation direction and magnitude, when the tube containing the slots is rotated. The embodiment of figures 18A, 18B can be made by making suitable material removal patterns in four tubes. In figures 18A, 18B all components with a reference number with an affix “a” have the same function as the component with the same reference number without affix “a” in figure 17.

[109] As shown in figure 18A, the intermediate tube 3 has, e.g., four equidistant steering wires 16(i). Outer tube 203 is provided with longitudinal slots 309(i) - one for each steering wire 16(1) — which are tangentially aligned with respective steering wires 16(1). A sliding notch 307(i) is provided in longitudinal slot 309(1).

Sliding notch 307(1) is attached to steering wire 16(i) and can move freely in the longitudinal direction of longitudinal slot 309(1). L.e., sliding notch 307(i) is guided in the longitudinal direction by longitudinal slot 309(i) and can only move in the desired steering wire direction.

[110] Steering wire 16(3), longitudinal slot 309(3), and sliding notch 307(3) are explicitly shown in figure 18A. Steering wire 16(1) is located opposite, i.e., at a 180 degrees tangentially rotated location, to steering wire 16(3) and not visible in figure 18A. Outer tube 203 has a longitudinal slot 309(1) with sliding notch 307(1) located on the opposite side but also closer to the proximal (right) end of the instrument than longitudinal slot 309(3).

[111] Only one additional tube needs to be added about outer tube 203 to complete the steering mechanism for steering wires 16(1), 16(3). A first ring 321 made from this additional tube is attached to outer tube 203 at a distal location from longitudinal slot 309(3), and a second ring 323 is attached to outer tube 203 at a proximal location from longitudinal slot 309(1).

[112] As shown in figure 18B, the additional tube includes a control tube portion 302a(1,3) containing a helical slot 303a(3) and a sliding notch 305a(3) inside helical slot 303a(3). The control tube portion 302a( 1,3) also contains a helical slot 303a(1) and a sliding notch 305a(1) [not visible] inside helical slot 303a(1). Helical slots 303a(1) and 303a(3) are spiraling in opposite directions. Control tube portion 302a(1,3) can rotate about outer tube 203 between first ring 321 and second ring 323 but cannot move in the longitudinal direction between first ring 321 and second ring 323 — apart from some possible play resulting from the manufacturing process.

Sliding notches 305a(1) and 305a(3), respectively, are attached to sliding notches 307(1) and 307(3), respectively, in outer tube 203, such that also sliding notches 305a(1) and 305a(3), respectively, are attached to steering wires 16(1) and 16(3), respectively. When control tube portion 302a(1,3) is rotated around the coaxially arranged instrument, as indicated with reference number R1, helical slots 303a(1) and 303a(3), respectively, will actuate both the attached sliding notches 307(1) and 305a(1), and the attached sliding notches 307(3) and 305a(3), respectively, in a longitudinal but opposite way, of which the principles were explained with reference to figure 17.

[113] In this way, a simple, compact and easy to manufacture solution is created for attaching pairs of individual steering wires to a single and simple to couple element that can be rotated by for example an electric actuation motor in a robot arm directly. The mechanism does not need to be manufactured as separate parts that require individual assembly, but now it can be, for example, (laser) cut integrally and pre-assembled in some tubes, as is, e.g., described in

WO2016089202. Methods of how to establish the connection between the rotatable control tube portion 302a(1,3) and such a motor, or a rotation actuation element in a hand held handle will be described further down in this document.

[114] Figure 19 shows an example of a steering unit that one obtains when two of the mechanisms as shown in figure 17 with a single control tube portion are used to control longitudinal movements of two pairs of opposite steering wires 16(1).

[115] In this way, one can actuate a second pair of steering wires 16(1), that for example steer the tip in a plane perpendicular to the first steering plane associated with the first pair of steering wires 16(1), with a second rotatable control tube portion. One can add a steering mechanism for a second pair of steering wires 16(1) easily and without significant extra costs or effort when one cuts a second assembly of the mechanism as in figures 18A, 18B in the same piece of the additional tube located around outer tube 203. This will only add a limited length of additional tube with very low material cost and will only increase the (laser) cutting time with a few seconds.

[116] In figure 19, all reference numbers which are the same as in figure 17 relate to the same components. The extra reference numbers are explained now.

[117] In addition to figure 17, figure 19 shows two steering wires 16(2), 16(4). It is assumed that steering wire 16(4) is located at a 180 degrees tangentially rotated location relative to steering wire 16(2). The mechanism contains a further sliding member 302(2,4) with slit-shaped opening 303(2) for steering wire 16(2) and an extra slit-shaped opening 303(4) for steering wire 16(4). A pin 305(2), 305(4), respectively, is attached to steering wire 16(2), 16(4), respectively, and accommodated in slit-shaped opening 303(2), 303(4), respectively. Slit-shaped opening 303(2), 303(4), respectively, is arranged at an angle y, J, respectively, relative to its longitudinal axis, respectively. In most practical cases a =B=7=20.

When one now moves sliding member 302(2,4) down, as indicated with arrow F6, steering wire 16(4) will move in the right direction, as indicated with arrow F5, and steering wire 16(2) will move in the left direction, as indicated with arrow F4. If y =

J, steering wires 16(2), 16(4) will move along the same length be it in opposite directions such that one of them is generating a pulling force and the other one is developing a pushing force, thus causing the tip to deflect. The two steering wires 16(2), 16(4) are actuated simultaneously.

[118] Figures 20A, 20B show an implementation of the steering unit of figure 19 in an instrument manufactured from some tubes and in which four steering wires can move the instrument tip in all directions. Of course, the slots can be shaped such that one can establish any desired actuation direction and magnitude, when the tube containing the slots is rotated. The embodiment of figures 20A, 20B can be made by making suitable material removal patterns in four tubes. In figures 20A, 20B all components with a reference number with an affix “a” have the same function as the component with the same reference number without affix “a” in figure 19.

[119] As shown in figure 20A, the intermediate tube 3 has, e.g., four equidistant steering wires 16(i). Outer tube 203 is provided with longitudinal slots 309(i) - one for each steering wire 16(i) — which are tangentially aligned with respective steering wires 16(1). So, the longitudinal slots 309(1) are also located at tangentially equidistant locations. A sliding notch 307(i) is provided in longitudinal slot 309(1).

[120] Steering wires 16(3), 16(4), longitudinal slots 309(3), 309(4), and sliding notch 307(3), 307(4) are explicitly shown in figure 20A. Steering wires 16(1), 16(2), respectively, are located opposite, i.e., at a 180 degrees tangentially rotated location, to steering wires 16(3), 16(4), respectively, and not visible in figure 20A.

Outer tube 203 has longitudinal slot 309(1) with sliding notch 307(1) located on the opposite side but also closer to the proximal (right) end of the instrument than longitudinal slot 309(3) and longitudinal slot 309(2) with sliding notch 307(2) located on the opposite side but also closer to the proximal (right) end of the instrument than longitudinal slot 309(4).

[121] Only one additional tube needs to be added around outer tube 203 to complete the steering mechanism for steering wires 16(i). The arrangement with first ring 321 and ring 323 is the same as in figures 18A, 18B made from this additional tube. The embodiment of figures 20A, 20B includes a third ring 327 attached to outer tube 203 at a proximal location from second ring 323 and from longitudinal slots 309(2), 309(4).

[122] Like in figures 18A, 18B longitudinal slots 309(1), 309(3) and sliding notches 307(1), 307(3) are located between first ring 321 and second ring 323.

Longitudinal slots 309(2), 309(4) and sliding notches 307(2), 307(4) are located between second ring 323 and third ring 327.

[123] In figures 20A, 20B the arrangement of control tube portion 302a(1,3), steering wires 16(1), 16(3), first ring 321, second ring 323, longitudinal slots 309(1), 309(3), sliding notches 307(1), 307(3), and helical slots 303a(1), 303a(3) is the same as in figures 18A, 18B.

[124] As shown in figure 20B, the additional tube includes a further control tube portion 302a(2,4) containing a helical slot 303a(4) and a sliding notch 305a(4) inside helical slot 303a(4). The further control tube portion 302a(2,4) also contains a helical slot 303a(2) and a sliding notch 305a(2) [not visible] inside helical slot 303a(2). Helical slots 303a(2) and 303a(4) are spiraling in opposite directions.

Further control tube portion 302a(2,4) can rotate about outer tube 203 between second ring 323 and third ring 327 but cannot move in the longitudinal direction between second ring 323 and third ring 327 — apart from some possible play resulting from the manufacturing process. Sliding notches 305a(2) and 305a(4), respectively, are attached to sliding notches 307(2) and 307(4), respectively, in outer tube 203, such that also sliding notches 305a(2) and 305a(4), respectively, are attached to steering wires 16(2) and 16(4), respectively,. When further control tube portion 302a(2,4) is tangentially rotated around the coaxially arranged instrument, helical slots 303a(2) and 303a(4), respectively, will actuate both sliding notches 307(2) and 305a(2), and 307(4) and 305a(4), respectively, in a longitudinal but opposite way, of which the principles were explained with reference to figure 19.

[125] In this way, a simple, compact and easy to manufacture solution is created for attaching pairs of individual steering wires to a simple to couple element that can be rotated by for example an electric actuation motor in a robot arm directly.

The two control tube portions 302a(1,3), 302a(2,4) can be tangentially rotated individually to steer the instrument tip in any direction. The mechanism does not need to be manufactured as separate parts that require individual assembly, but now it can be, for example, laser cut integrally and pre-assembled in some tubes, as is, e.g., described in WO2016089202. Methods of how to establish the connection between the rotatable further control tube portion 302a(2,4) and such a motor, or a rotation actuation element in a hand held handle will be described further down in this document.

[126] Furthermore, as compared to the embodiments described in figures 10-14, the number of required actuators is reduced. Steering of an instrument tip in any direction can now be accomplished by only two rotating actuation means, instead of four individual mechanisms that one would need for accomplishing tip steering in any direction, with embodiments described in figures 10-14.

[127] Sometimes, however, it might be practical to actuate tip steering with a translation means instead of a rotating means. For example, one can imagine, that in a hand held handle one would like to steer the tip with a sliding knob. In that case it would be beneficial to incorporate a sliding tube instead of a rotating tube to establish tip steering. Figure 21 schematically shows a steering unit that actuates two steering wires as a reaction on sliding one element in a longitudinal direction.

[128] In figure 21 the same reference numbers as used in figure 17 refer to the same components. The principle schematic arrangement of figure 21 includes a longitudinally sliding member 331 which can be moved back and forth in the longitudinal direction as indicated with arrow F6. Longitudinal sliding member 331 includes a slit-shaped opening 335 and the sliding member 302(1,3) is provided with a pin 333 accommodated in slit-shaped opening 335. Slit-shaped opening 335 is arranged at an angle € to longitudinal direction of steering wire 16(1) such that 0 < € < 90 degrees. When sliding member 331 is moved back or forth in its longitudinal direction, sliding member 301 is forced to moved upward/downward as indicated with arrow F1, and steering wires 16(1), 16(3) are forced to move back or forth in the longitudinal direction as indicated with arrow F2, F3 in the direction of the longitudinal axis of the instrument.

[129] Like in figure 17, steering wires 16(1), 16(3) will move along the same length be it in opposite directions such that one of them is generating a pulling force and the other one is developing a pushing force, thus causing the tip to deflect. The two steering wires 16(1), 16(3) are actuated simultaneously.

[130] Figures 22A, 22B show an embodiment in which the principles of figure 21 are implemented. The steering unit arrangement of figures 18A, 18B contains the entire instrument of figures 20A, 20B, as is shown in figure 22A. In addition to the components shown in figures 18A, 18B, the instrument includes a longitudinal slider 33 1a which is configured to actuate rotation of the control tube portion 302a(1,3) by longitudinal movements F6. In figures 22A, 22B all components with a reference number with an affix “a” have the same function as the component with the same reference number without affix “a” in figure 21.

[131] To that end, in the shown example, longitudinal slider 331a is provided with a longitudinal extension 343 which extends into a longitudinal slot 339 of a fourth ring 337. The width of slot 339 matches the width of longitudinal extension 343 such that longitudinal extension 343 can only move in the longitudinal direction of slot 339 and not in the tangential direction. Moreover, fourth ring 337 is attached such that it cannot rotate relative to outer tube 203. To that end, it may be directly attached to outer tube 203, e.g. by (laser) welding or to first ring 321 which is attached to outer tube 203. As a person skilled in the ort will understand, there are many other possible mechanisms to prevent longitudinal slider 331a from rotation relative to outer tube 203.

[132] In an embodiment, fourth ring 337 may have an inner diameter such that it matches the outer diameter of outer tube 203 and can be directly attached to outer tube 203. Alternatively, fourth ring 337 may have an inner diameter such that matched the outer diameter of first ring 321 such that can be attached to first ring 321. In this latter example, fourth ring 337 and longitudinal slider 331a can be made from a further additional tube by providing that further additional tube with a suitable material removal pattern. That further additional tube 1s coaxial with and longitudinally aligned with the additional tube from which the components 321, 302a(1,3), 305a(1), 305a(3), 303a(1), 303a(3), and 323 are made.

[133] Longitudinal slider 331a is provided with a helical slot 335a and a sliding notch 333a which is located inside helical slot 335a. Sliding notch 333a is attached to control tube portion 302a(1,3). Therefore, sliding notch 3334 cannot move in a longitudinal direction and can only move in a tangential direction. In use, sliding notch 333a is forced to rotate in a tangential direction by moving longitudinal slider 331ain the longitudinal direction F6. This will cause control tube portion 302a(1,3) to rotate tangentially and, as a consequence, the deflectable tip is deflected by opposite longitudinal movements of steering wires 16(1), 16(3).

[134] In this way a normally more complex mechanism, made from individually manufactured and assembled parts is again transformed to an easy, cheap and pre- assembled mechanism by the simple addition of one extra tube. In a further embodiment, one can incorporate two of the mechanisms as shown in figures 22A, 22B in the instrument, such that deflection of the tip in all directions, could be established by two linear actuators instead of two rotating actuators. To that end, an arrangement similar to or identical to the one shown in figure 22B with the components 337, 339, 343, 331a, 333a and 335a can be applied on an instrument as shown in figure 20B, where such an arrangement is configured to control rotation of control tube portion 302a(2,4) by an extra longitudinal slider like longitudinal slider 33 1a.

[135] One can even further reduce the number of required steering actuators. For example if one wishes to apply a hand held handle with only one steering input to tully control the direction and magnitude of tip steering and if one wishes to accomplish that with only movement of one finger instead of a less controllable and accurate arm and wrist movement, one can envision the following,

[136] Figure 23 schematically shows a steering unit that comprises one steering input mechanism that can control two sets of steering wires for steering an instrument tip in any direction.

[137] To that end, the setup of figure 23 comprises all features of figure 21. In addition, the setup includes steering wires 16(2), 16(4) and a sliding member 302(2,4) configured to control longitudinal movement of steering wires 16(2), 16(4). It is assumed that steering wire 16(2) is located at a 180 degrees tangentially rotated location relative to steering wire 16(4). The four steering wires 16(1), 16(2), 16(3), 16(4) are located at equidistant locations. Sliding member 302(2,4) contains a slit-shaped opening 303(2) for steering wire 16(2) and a slit-shaped opening 303(4) for steering wire 16(4). A pin 305(2), 305(4), respectively, is attached to steering wire 16(2), 16(4), respectively, and accommodated in slit-shaped opening 303(2), 303(4), respectively. Slit-shaped opening 303(2), 302(4), respectively, is arranged at an angle 1, 9, respectively, relative to the longitudinal direction. In most practical cases 1 = 9. When one now moves sliding member 302(2,4) up/down, as indicated with arrow F7, steering wires 16(2), 16(4) will move in opposite longitudinal directions, as indicated with arrows F4, F5. If 1 = 9, steering wires 16(2), 16(4) will move along the same length be it in opposite directions such that one of them is generating a pulling force and the other one is developing a pushing force, thus causing the tip to deflect. The two steering wires 16(2), 16(4) are actuated simultaneously.

[138] The setup of figure 23 also includes a sliding member 349 provided with a longitudinal slot 351 accommodating a pin 353 which is attached to sliding member 302(2,4). Sliding member 349 can move in longitudinal direction F9 without moving sliding member 302(2,4) in the longitudinal direction. However, when sliding member 349 moves in a direction F8 perpendicular to longitudinal direction

F9 sliding member 302(2,4) will be forced by pin 353 inside slot 351 to move in direction F7.

[139] Moreover, longitudinal sliding member 331 is provided with a slot 355 extending in direction F8 and accommodating a pin 357 which is attached to sliding member 349. Therefore, if sliding member 349 is moved in longitudinal direction

F9, longitudinal sliding member 331 is moved in its longitudinal direction F7 too.

[140] Thus, sliding member 349 can be moved in all directions in a plane of figure 23 and will, thereby, control longitudinal movement of all four steering wires 16(1). The amount of up/down movement F9 will determine the amount of opposite longitudinal movements of steering wires 16(2), 16(4) and the amount of longitudinal back/forth movement F8 will determine the amount of opposite longitudinal movements of steering wires 16(1), 16(3). So, both the amount of deflection and the direction of deflection in 3D space is controlled by a single component, i.e., sliding member 349.

[141] Figure 24 shows the outside of an embodiment of a steering unit in which the mechanism of figure 23 is implemented with coaxially arranged tubes. All components with a reference number with an affix “a” have the same function as the component with the same reference number without affix “a” in figure 23. Note that the steering mechanism for steering wires 16(1), 16(3) is implemented proximally from the steering mechanism for steering wires 16(2) , 16(4).

[142] At its proximal end, the instrument is provided with the same functional mechanism as shown in figures 20A, 20B, be it that the two control tube portions 302a(1,3) and 302a(2,4) are implemented in a reversed longitudinal order.. On top of control tube portion 302a(1,3), a same longitudinal slider 3314 is applied as in figure 22B. The helical slot 335a 1s now spiraling in the opposite direction but that is technically not important. Longitudinal slider 331a is again configured such that it cannot rotate relative to the underlaying rings 321, 323, e.g., by a mechanism including longitudinal extension 343 inside longitudinal slot 339 inside fourth ring 337 which are not shown in figure 24 but visible in figure 22B. However, like in figures 22A, 22B, longitudinal slider 331a can slide in the longitudinal direction, as indicated with F6, in order to rotate control tube portion 302a(1,3) to operate steering wires 16(1), 16(3) as explained above.

[143] Moreover, longitudinal slider 331a is provided with a tangential slot 355a accommodating a notch 357a.

[144] Proximally from longitudinal slider 33 1a, the instrument includes a slider 349a. In the tube underlaying, the instrument includes a rotatable operating mechanism for steering wires 16(2), 16(4) as shown on the proximal end of figure 20B. In this embodiment slider 349a is provided with a longitudinal slot 351a accommodating a sliding notch 353a. Sliding notch 353a is attached to rotatable control tube portion 302a(2,4). Longitudinal slider 33 1a and slider 349a can be made by providing a single tube with a suitable material removal pattern. However, alternatively they can be made from different tubes.

[145] A driving element, like tube 359 (which is not shown in figure 24 but shown in figures 25A, 25B) is provided on top of both longitudinal slider 3314 and slider 3494. At its distal end, driving tube 359 is attached to slider 3494 and at its proximal end driving tube 359 is attached to notch 357a. The result is that if one only rotates the driving tube 359, control tube portion 302a(2,4) is rotated which actuates steering wires 16(2), 16(4) for a first steering plane. Then, longitudinal slider 331a is not actuated because notch 357a can freely move in the tangential direction in tangential slot 355a and does not initiate translation of longitudinal slider 33 1a in the longitudinal direction. However, when driving tube 359 is only translated in the longitudinal direction, longitudinal slider 33 1a is also moved in the longitudinal direction and rotatable control tube portion 302a(1,3) is rotated by notch 333a inside helical slot 335a, as explained with reference to figures 22A, 22B. This actuates steering wires 16(1), 16(3) for a second steering plane. Then, rotatable control tube portion 302a(2,4) is not actuated because sliding notch 353a can freely move in longitudinal slot 351a in the longitudinal direction. When one rotates and translates driving tube 359, both steering planes are actuated. In this way, one control feature (driving element or tube 359) can control two steering planes. This embodiment again only requires the addition of one extra tube with a pre-assembled number of parts and does not significantly increase the required manufacturing effort nor the volume (bulkiness) of the instrument body.

[146] It is observed that many alternative embodiments are possible. E.g., the function of sliding notch 353a and slider 349a may be reversed. I.e., slider 349a may be attached to rotatable control tube portion 302a(2,4) instead of to driving tube 359 and, then, sliding notch 353a is attached to driving tube 359 and not to rotatable control tube portion 302a(2,4). This is a more compact arrangement because, then, slider 349a is configured for rotation only and does not need space for longitudinal movements.

[147] Moreover, slider 3494 and longitudinal slider 3314 can be implemented in reversed longitudinal order such that slider 349a is on the proximal side of longitudinal slider 331a.

[148] This embodiment is for example very useful in case one wants a simple hand held handle with an accurate means of controlling tip steering in all directions in a way that resembles for example the use of a mouse pad by using one finger only.

[149] Figures 25A, 25B show schematic views of a permanently attached handle 363. Figure 25A shows a very schematic cross sectional view of handle 363 and the proximal end of the steerable instrument. It shows driving tube 359 surrounding all other steering tubes (not drawn again in figure 25A) and which driving tube 359 is attached to slider 349a and notch 357a shown in figure 24. An extra operating tube 358 may be applied which is surrounding and attached to driving tube 359 and may be made of a material, e.g., a suitable plastic with a roughened surface, such that one can easily shift and/or rotate the operating tube 358. Thus, operating tube 358 can be moved in a longitudinal direction and/or a circumferential direction by for example a thumb, as is shown in figure 25B. In this way, one can deflect the tip of the steerable instrument in any direction and with any magnitude with only one thumb or other finger, as desired. An extra cover 361 may be applied on top of operating tube 358 with an opening 360 through which a user can operate operating tube 358 with a finger.

[150] Figure 26 shows handle 363 like the one shown in figure 25A but now with a simple coupling mechanism that allows for detaching operating tube 358 and cover 361 from the steerable instrument, to enable multiple uses of the handle and single use of the steerable instrument. As drawn, coupling and detaching can, in an example, be established by for example a locking pin 365 configured to lock operating tube 358 to driving tube 359 and a locking pin 367 configured to lock cover 361 to outer tube 203. Such locking pins can be pulled back to unlock. Once locked locking pin 365 causes operating tube 358 to be only movable together with driving tube 359 in all directions and locking pin 367 causes cover 361 to be locked to outer tube 203 in all directions. Obviously all other well-known detachable locking mechanisms such as bayonet locks, locking balls, levers or other mechanisms can be used, instead of locking pins. It is easy to understand that this configuration has many advantages as compared to currently available solutions.

The instrument part is relatively cheap to manufacture and is very compact although it contains all complexity needed for translating one single finger input to full control of the instrument’s tip. Furthermore, the instrument can be made of one single material, which is very advantageous for improving waste management. The re-useable handle contains a minimum of mechanical parts and potentially can easily be cleaned and re-sterilized and also is relatively cheap to manufacture. 151] Figure 27 presents a more simplified form of the steering unit shown in figure 23. The same reference numbers refer to the same components as in figure 23. Instead of sliding member 331 and sliding member 349, the setup of figure 27 includes one sliding member 371 which can be moved in opposite longitudinal directions F6a, Fob and opposite directions F8a, F8b which are perpendicular to longitudinal directions F6a, F6b. Sliding member 371 includes slot 335 accommodating pin 333 and a further slot 369 accommodating pin 353. In an embodiment further slot is arranged in a direction at a same, but opposite angle relative to the longitudinal direction. In fact, apart from components 371, 333, 335, 353 and 369, the setup of figure 27 is the same as of figure 19.

[452] As a person skilled in the art will understand, independent control of longitudinal movements of the sets of steering wires 16(1)/16(3) and 16(2), 16(4) is also possible with the mechanism of figure 27 by a suitable movement of sliding member 371. For instance, by moving sliding member 371 in a straight direction coinciding with further slot 369 one only operates steering wires 16(1), 16(3), and by moving sliding member 371 in a straight direction coinciding with slot 335 one only operates steering wires 16(2), 16(4). With other movements one controls longitudinal movements of all four steering wires.

[153] Figures 28 A thru 28D show an embodiment in which the mechanism of figure 27 is implemented by several tubes. Figure 28 A shows the tube assembly containing the tubes required for the steering wires 16(1) and the attached notch and guiding slot. Figure 28A is identical to the one shown in figure 20A, be it that rings 321, 323, 327 are not shown in figure 28A. The same reference numbers refer to the same components. Figure 28B shows the rotating tubes with the slots that control steering element displacement when these tubes are rotated. Le, Figure 28B is identical to figure 22B and the same reference numbers refer to the same components.

[154] Figure 28C shows a first tube portion 373 and a second tube portion 375. First tube portion 373 1s arranged on top of a portion of rings 321 and 323 as well as on rotatable control tube portion 302a(1,3). Moreover, first tube portion 373 is attached to rotatable control tube portion 302a(1,3) but can freely rotate around rings 321 and 323. Thus, rotating first tube portion 373 causes opposite longitudinal movements of steering wires 16(1), 16(3). Second tube portion 375 is arranged on top of a portion of rings 323 and 327 as well as on rotatable control tube portion 302a(2,4). Moreover, second tube portion 375 is attached to rotatable control tube portion 302a(2,4) but can freely rotate about rings 323 and 327. Thus, rotating second tube portion 375 causes opposite longitudinal movements of steering wires 16(2), 16(4). [1661 Figure 28D shows a single drive tube 376 provided with a first helical slot 377 and a second helical slot 379. First and second helical slots 377, 379 are spiraling in opposite directions. A notch 381 inside second helical slot 379 is shown, which notch 381 is attached to second tube portion 375. There is also a notch [not visible in figure 28D] inside helical slot 377, which is attached to first tube portion 373. It is observed that first tube portion 373 and second tube portion 375 can be left out. Then, notch 381 is directly attached to rotatable control tube portion 302a(2,4), and the notch inside first helical slot 377 is directly attached to rotatable control tube portion 302a(1,3).

[166] Helical slots 377, 379 force the notches 381 in a rotating direction dependent on the longitudinal and rotational movement of drive tube 376. Each rotational and longitudinal position of drive tube 376 forces the notches 381 in a predetermined discrete position associated with a unique deflected position of the tip in 3D space. Appropriate software and control motors could easily control the movement of drive tube 376 such that the desired tip steering is established. For a hand controlled version, this mechanism is also useable. If one only translates drive tube 376, two steering planes are actuated simultaneously in the same amount. Mentally, if one shifts drive tube 376 forward and back in the longitudinal direction, one would expect that the tip moves down and up in a vertical plane. But because two steering planes are actuated simultaneously, the tip will move in the vertical plane as well as in the horizontal plane with the same magnitude. The tip steering direction therefor has a 45 degree angle deviation from the vertical plane. To solve this, the instrument shaft may be connected with a 45 degrees offset to the handle. This will result in tip steering in planes corresponding to what one would expect.

Pushing forward drive tube 376 and pulling it back will now result in an down and up movement in a vertical plane. Rotating drive tube 376 will now result in tip movement in the horizontal plane.

[157] All above embodiments show mechanisms based on the assumption that either a rotating or a sliding coaxially arranged tube segment is the preferable way to enable a coupling to a robot or a hand held handle that can be established by an end user on site. From the perspective of integral manufacturing an instrument with a minimum of separate parts and a minimum of assembly effort, one could also use the methods as proposed in WO20091 12060, WO2009127236, WO2017213491, and WO2018067004 for creating other interface types.

[158] For example, figures 29A, 29B, 29C show a mechanism that can easily be made integrally and pre-assembled from a tube wall. Figure 29A shows a gear mechanism and figure 29B shows a portion thereof on an enlarged scale. Figure 29A shows a portion of the instrument with intermediate tube 3 provided with steering wires 16(i) of which steering wires 16(1), 16(2) are visible. Outer tube 203 is shown with a first longitudinal slot 413 in which a first serrated slider 403(2) with teeth 406 is located and a second longitudinal slot 415 in which a second serrated slider 403(1) with teeth 408 is located. First serrated slider 403(2) is attached to steering wire 16(2), e.g., by (laser) welding a portion 409 of first serrated slider 403(2) material. Second serrated slider 403(1) is attached to steering wire 16(1), e.g., by (laser) welding a portion 418 of second serrated slider 403(1) material. In between first and second serrated sliders 403(2), 403(1) outer tube 203 has a strip like portion 419 functioning as a spacer between first and second serrated sliders 403(2), 403(1). Strip like portion 419 has a through hole 417 accommodating a gear 401 with teeth 417. Gear 401 has a recess 404 in its centre.

[159] Figure 29A, 29B shows some fracture elements 407 used during the manufacturing process as explained in detail in, e.g., WO2016089202.

[160] As shown in figure 29C, in this embodiment, the instrument has a cover tube 410 outside outer tube 203. Cover tube 410 has an opening 411 aligned with opening 404 of gear 401.

[161] In this embodiment steering wires 16(1), 16(2) can be moved in opposite longitudinal directions by rotating gear 401. Rotation of gear 401 can be established by an actuator from which a suitable axle is inserted in recess 404 via opening 411.

The advantage of a mechanism like this may be that when compared to embodiments as presented in figures 15 thru 28D this configuration does not require additional layers of tubing to form a complete mechanism that works with a rotational input. Note that, here steering wires 16(). 16(2) are shown adjacent to one another but they can be located at tangentially 180 rotated locations by having a suitable further transmission system between gear 401 and steering wires 16(1), 16(2), e.g. implemented in the same tube from which the steering wires 16(1), 16(2) are made.

[162] The steering wires 16(1), 16(2) can be substituted for longitudinal control elements configured to perform a function of the instrument, like locking/unlocking bent instrument parts, operating one or more tools at the distal end, etc.

[163] Another way of using the mechanism of figures 29A-29C provides for even more advantages. The embodiments as described in figures 15 thru 28D, describe mechanisms that can be used to actuate only two opposite moving steering wires that can steer the instrument tip in one plane. By actuation of two planes, independent from each other, one can steer the instrument tip in any direction, by controlling four steering wires.

[164] However, the use of only four steering wires limits the obtainable force with which a tip can be steered and therefor limits the amount of force that the tip can apply to surrounding tissue. These obtainable forces are dependent on the strength of the steering wires. One cannot increase the dimensions, and therefore the strength of the steering wires limitless. With increasing dimensions also the stiffness increases. Also with steering wires that are relatively thick, there is a probability that steering wires are plastically deformed instead of only elastically when the tip is curved sharper than purely elastic deformation of the steering wires allow. Plastic deformation potentially shortens fatigue life of the steering wires to unacceptable levels. Therefore, in some occasions, one would like to use more than four steering wires per steerable section for obtaining the composite steering wires strength without compromising bending stiffness and deformation characteristics (fatigue life). A big disadvantage is as follows. For example, if one wishes to use eight steering wires and one wishes to steer the instrument tip in a certain direction, usually four steering wires have to be pulled and four steering wires have to be pushed simultaneously, each over a different amount of displacement. Of course,

one can increase the number of mechanisms as shown in figure 15 thru 28D to the number of steering wires that are required, but then also the number of actuators has to increase. Controlling an increased number of actuators is practically not doable by hand control and is also more complex to do with for example software and electric motors.

[165] The mechanism of figures 29A, 29B, 29C provides for a solution when used in a slightly different way. Figures 30A, 30B show a mechanism in which gear 401 can rotate around an axle 423(1,2) that 1s inserted in recess 404 of gear 401 and attached to an underlying longitudinal control element 421(1,2) arranged in intermediate layer 3 in which also steering wires 16(1) are located. Axle 423(1,2) can be made from outer tube 203, e.g. by cutting a circular portion in the centre of gear 401 and attaching the circular portion to longitudinal control element 421(1,2).

Gear 401 is arranged in a longitudinal slot 402.

[166] Longitudinal control element 421(1,2) can slide in a longitudinal way, parallel to the instrument’s axis 229. When one translates longitudinal control element 421(1,2), axle 423(1,2) with gear 401, is also moved in a longitudinal way in longitudinal slot 402 and will pull or push the two engaged steering wires 16(1), 16(2) in the same longitudinal direction. However, like in a car’s differential, steering wires 16(1), 16(2) can displace over a different distance, because gear 401 rotates freely. The potentially different displacements of steering wires 16(1), 16(2) ,e.g., caused by one or more bent parts of the instrument body because the body is inserted in a curved channel, will be such that an equilibrium of push or pull forces is reached. Therefore, one automatically gets the correct displacement of two steering wires whilst the composite steering force is equally divided over the two wires.

[167] The mechanisms as explained with reference to figures 15 thru 28D, that each control one steering plane with two steering wires 16(1), 16(i+1) can also be used to control longitudinal movements of several longitudinal control element 421(1,i+1) that hold several respective gears 401 instead of the steering wires directly. Then, each respective longitudinal control element 421(i(,i+1) controls longitudinal movement of two steering wires 16(1), 16(i+1) and compensates mutual path length differences between them. In that way, for example, one can use eight steering wires to steer the tip in any direction instead of four steering wires.

One can arrange the steering wires such that the composite strength of the eight wires 1s much higher than that of four wires at the same flexibility and fatigue life.

The setup is shown in figure 31.

[168] Figure 31 shows a same steering arrangement as figure 17. So, it can be implemented with components (laser) cut in several coaxial tubes in a way as shown in figures 18A, 18B. The steering arrangement is shown for steering four longitudinal control elements 421(1,2), 421(3,4), 421(5,6), 421(7,8) in a steerable instrument with eight steering wires 16(1) — 16(8) which are equidistantly arranged about the circumference of the instrument. So, every steering wire 16(1) 1s located 180 degrees tangentially rotated relative to steering wire 16(i+4). The shown steering arrangement steers longitudinal movements of a first longitudinal control element 421(1,2) and a second longitudinal control element 421(5,6). First longitudinal control element 421(1,2) controls longitudinal movements of steering wires 16(1), 16(2) via serrated sliders 403(1), 403(2) and a gear 401(5,6) as explained with reference to figures 30A, 30B. Second longitudinal control element 421(5,6) controls longitudinal movements of steering wires 16(5), 16(6) via serrated sliders 403(5), 403(6) via a gear 401(5,6) in the same way.

[169] Figure 31 also shows one single sliding member 302(1,2,5,6) with a slit- shaped opening 303(1,2) for longitudinal control element 421(1,2). A pin 305(1,2) is attached to longitudinal control element 421(1,2) and accommodated in slit- shaped opening 303(1,2). Slit-shaped opening 303(1,2) is arranged at angle B relative to the longitudinal axis. Sliding member 302(1,2,5,6) also has a slit-shaped opening 303(5,6) for longitudinal control element 421(5,6). A pin 305(5,6) is attached to longitudinal control element 421(5,6) and accommodated in slit-shaped opening 303(5,6). Slit-shaped opening 303(5,6) is arranged at an angle a relative to the longitudinal axis. In most practical cases o = B. When one now moves sliding member 302(1,2,5,6) down, as indicated with arrow F1, steering wires 16(5,6) will move in the right direction, as indicated with arrow F2, and steering wires 16(1), 16(2) will move in the left direction, as indicated with arrow F3. If a = BB, steering wires 16(1), 16(5) will move along the same length be it in opposite directions such that one of them is generating a pulling force and the other one is developing a pushing force. The same holds for steering wires 16(2), 16(6). The four steering wires 16(1), 16(2), 16(5), 16(6) are actuated simultaneously, and the tip will be deflected. Path length differences between adjacent steering wires 16(1) and 16(2) and between adjacent steering wires 16(5) and 16(6) will be compensated, as explained with reference to figures 30A, 30B. In this way, one can increase steering strength, without adverse effects on flexibility or deformation characteristics of the steering wires.

[170] It is observed that in the setup of figures 30A, 30B, and 31 the longitudinal control elements 421(1,i+1) are cut from the same intermediate tube as steering wires 16(1), 16(i+1) and serrated sliders 403(1), 403(i+1) are cut in outer tube 203.

However, in an alternative arrangement, longitudinal control elements 421(i,i+1) are cut from a tube inside or outside that intermediate tube and the steering wires 16(1), 16(i+1) are serrated themselves. Then, also gear 401 is located in, and possibly cut from the intermediate tube. Then, the longitudinal elements on the distal side in figure 31 are steering wires 16(1), 16(2), 16(5), 16(6) and gears 401(1,2), 401(5,6) drive them directly.

[171] The arrangement of figure 31 can be implemented twice in order to control longitudinal movements of all eight steering wires 16(1) — 16(8). To that effect, all setups of figures 19-28D may be used such that the steering unit drives longitudinal control elements 421(1,1+1) instead of the steering wires 16(1) — 16(8), and each of the longitudinal control elements 421(i,i+1) controls longitudinal movements of two adjacent steering wires 16(1), 16(i+1). Moreover, the embodiment of figure 31 is not restricted to eight steering wires 16(1) — 16(8), but can be used for 8*S steering wires where S=1,2 3, ….

[172] It is also observed that the setup of figure 30A, 30B, 31 can be used to control longitudinal movement of one or more longitudinal control elements 421 having other functions of the instrument, like locking/unlocking bent portions of the instrument in use, or operating one or more tools at the distal end of the instrument.

[173] Figures 32A, 32, B, 32C, 32D show another way of using gears to actuate steering wires. Here, the same reference numbers as used in figures 29A, 29B, 29B refer to the same components. In this embodiment, the serrated sliders 403(1), 403(2) are operated by a geared pinion 425. Figure 32D shows gears 427 of geared pinion 425 which are in contact with teeth 406, 408 of serrated sliders 403(1), 403(2).

[174] In an alternative embodiment, no sliders 403(1), 403(2) are applied but steering wires 16(1), 16(2) are themselves provided with a serrated side like serrated sliders 403(1), 403(2). In such an embodiment, gears 427 of geared pinion 425 directly contacts these serrated sides and drives steering wires 16(1), 16(2).

[175] Figure 32C shows that cover tube 410 may also be applied on top of outer tube 203 where cover tube 410 is provided with a suitable opening for letting pass geared pinion 425. Note that no cover tube 410 needs to be applied if steering wires 16(1), 16(2) are themselves serrated.

[176] Figure 33 shows an alternative for figures 22A, 22B. I.e., figure 33 schematically shows how a longitudinal movement can be translated in a rotating movement and vice versa by using gears. Figure 33 shows a longitudinal serrated element 429 and a rotatable serrated element 431 which are both in contact with the same gear 433. A rotating movement of rotatable serrated element 431 causes a longitudinal movement of longitudinal serrated element 429 and vice versa via gear 433. Longitudinal serrated element 429 can be implemented as a portion of a longitudinal slider like longitudinal extension 343 of longitudinal slider 331a of figure 22A. Rotatable serrated element 431 may be control tube portion 302a(1,3) of figure 22A. The mechanism can also be used as an alternative for figures 16A, 16B. Longitudinal serrated element 429 may be a steering wire 16(1) in which case steering wire 16(1) can be driven by rotation of rotatable serrated element 431.

[177] In a further embodiment, the setup of figure 33 can be used to drive two opposite steering wires 16(1), 16(3). The setup then includes two gears 433 configured to drive the opposite steering wires 16(1), 16(3), respectively, and which are then driven by rotatable element 431 such that rotating rotatable element 431 results in opposite longitudinal movements of the two opposite steering wires 16(1), 16(3).

[178] Moreover, the setup with control tube portion 302(2,4) can be substituted for an arrangement as shown in figure 33 in which another serrated rotatable element drives steering wires 16(2) and 16(4) — which are then also serrated - via gears.

[179] Figure 34 shows that a gear can be used to drive an output element at a different speed or magnitude of displacement as compared to the input element. For example, the arrangement shown in figure 34 includes two serrated longitudinal elements 429, 435. Their serrated sides are both in contact with a gear arrangement

437 having a first gear 439 with a first number of teeth and a second set gear 441with a second number of teeth. Here, the first number is smaller than the second number but that may be the other way around. First gear 437 contacts the serrated side of serrated longitudinal element 429 and gear 441 contacts the serrated side of serrated longitudinal element 435. Then, longitudinal movement of serrated longitudinal element 429 is slower than of serrated longitudinal element 435 depending on the gear ratio between gears 437, 441. Serrated longitudinal element 429 may be a portion of a sliding tube of an instrument. It is obvious that gear arrangement 437 can also be used in the setup of figure 33 instead of gear 433 in order to establish a desired ratio between rotation of rotatable serrated element 431 and translation of longitudinal serrated element 429.

[180] Figure 35 shows a schematic setup of an alternative for figures 28A-28D.

Figure 35 shows a schematic side view of, in this embodiment, a first rotatable element 443 and a second rotatable element 445 which, in this example have the same radius. A third rotatable element 447 is coaxially arranged with the first and second rotatable elements 443, 445. Rotatable element 445 may be proximal from rotatable element 443. Rotatable element 445 is provided with teeth 446 at its distal side and rotatable element 443 is provided with teeth 444 at its proximal side. A gear 450 is provided in between and contacting both teeth 444 and teeth 446. If gear 450 rotates rotatable elements 443, 445 will rotate in opposite directions.

[181] Gear 450 extends radially into a longitudinal opening 449 in third rotatable element 447. Longitudinal opening 449 has a serrated longitudinal side 448 with teeth engaging gear 450. Rotatable element 447 cannot only rotate but can also be moved in the longitudinal direction.

[182] This setup can be applied in the setup of figures 28A-28D, i.e, first rotatable element 443 may be control tube portion 302a(1,3) and second rotatable element 445 may be control tube portion 302a(2,4). Moreover, gear 450 is then located between them and they have opposing serrated sides 444, 446. Third rotatable element 447 then substitutes tubes 373, 375 and 359. If so, one can deflect the deflectable tip section in any direction in 3D space by operating third rotatable element 447, e.g., with a thumb, in its longitudinal and/or tangential direction, as explained with reference to figures 28A-28D.

[183] Mentally, if one shifts third rotatable element 447 forward and back in the longitudinal direction, one would expect that the tip moves down and up in a vertical plane. But because two steering planes are actuated simultaneously, the tip will move in the vertical plane as well as in the horizontal plane with the same magnitude. The tip steering direction therefor has a 45 degree angle deviation from the vertical plane. To solve this, the instrument shaft may be connected with a 45 degrees offset to the handle. This will result in tip steering in planes corresponding to what one would expect. Pushing forward third rotatable element 447 and pulling it back will now result in an down and up movement in a vertical plane. Rotating third rotatable element 447 will now result in tip movement in the horizontal plane.

[184] Figures 29 thru 35 present a few examples of how mechanisms with slotted elements with corresponding slider notches can be replaced with gear elements. In fact all slot and notch mechanisms could be replaced by gears and vice versa.

[185] Obviously, one can apply any number of the mechanisms as presented in all embodiments above to actuate any number of steering wires / longitudinal control elements or sets of steering wires / longitudinal control elements or differential drives. For example, if one would like to control two distal steerable sections, one could apply an appropriate combination of the embodiments above to obtain steering of any desired number of steering wires per steerable section whilst the number of actuator inputs could still be minimized to one actuation element (rotatable and sliding) per steerable section.

[186] One could also use the embodiments described above for actuation of not only steering wires but also for actuation of for example a longitudinal control element used for opening and closing of a surgical gripper or other tools.

[137] As discussed already, the above embodiments provide huge advantages over currently employed solutions. Currently employed solutions for controlling steering wires usually comprise many separately manufactured parts that require significant assembly effort. The above described embodiments show pre-assembled and easily manufactured parts that one almost gets for free when one keeps in mind that to create an instrument body one has to (laser) cut the required features for the flexible sections and the steering wires anyways. The addition of cutting the mechanisms for the described embodiments in the same tubes in the same manufacturing run is not more expensive and does not require more metal. Even the addition of one or two short tubes for completing the described mechanisms barely add effort or costs.

[188] Another huge advantage, which was also already discussed, is that a coupling between the instrument and external controllers like for example a re- useable hand held controller or a robot can easily be established because the difficult part of connecting the instrument’s individual steering wires to the remainder of the needed steering mechanisms is already established in the instrument itself. Also the number of required control elements in the external controllers is already reduced significantly by mechanisms in the instrument itself.

Possible couplings, that can be established easily by the end user on site can easily be envisioned.

[189] For example, when a rotating tube is used as an interface, one can easily cut slots in this tube that engage with a key or splines in the receiving part of the used hand controller or robot. Figures 36A, 36B, 36C show an example of the coupling of a disposable instrument 1 with two rotating tubes that engage in two hollow and keyed or splined axles of two electric actuator motors directly, without the addition of other mechanisms or parts in the robot.

[190] Figure 36A shows the proximal end of an example of the steerable instrument 1. It shows two control tube portions 302a(1,3), 302(2,4). However, there may one or more of such control tube portions as explained before. There may be extra tube portions on top of these control tube portions 302a(1,3), 302(2,4) to protect the helical slits 303a(i) from collecting dust etc. In the shown embodiment, control tube portion 302a(1,3), 302a(2,4), respectively, is provided with a plate 456, 458, respectively, attached to the outer surface of control tube portion 302a(1,3), 302a(2,4), respectively. Here plates 456, 458 are identical and tangentially aligned.

[191] Figure 36A shows a first motor 452 and a second motor 454 as well as first electrical wiring 453 and second electrical wiring 455, respectively, for first motor 452 and second motor 454, respectively. These wirings 453, 455 are configured to carry driving currents and suitable control signals to first and second motors 452, 454. Both first and second motors 452, 454 have a hollow driving shaft. Figure 36A shows both electrical motors 452 and 454 in their decoupled state. Figure 36B shows the state where steerable instrument is inserted in the hollow shafts of first and second motors 452, 454. In that state, plate 457 of control tube portion

302a(2,4) is inserted into a slot 460 of the hollow shaft of second motor 454 such that rotation of this hollow driving shaft causes rotation of control tube portion 302a(2,4), cf. figure 36C. Though not shown, first motor 452 has a similar slot inside its hollow driving shaft for accommodating plate 456 such that rotation of the hollow driving shaft of first motor 452 causes rotation of control tube portion 302a(1,3). In this way rotations of control tube portions 302a(1,3), 302a(2,4) can be independently controlled, e.g., by suitable software stored in a processor of a robotic system such as to deflect the tip of the steerable instrument in any desired direction in 3D space.

[192] In the decoupled state, slot 460 of second motor 454 and similar slot of first motor 452 are tangentially aligned, like plates 457, 456, such that control tube portion 302a(2,4) can pass the slot of first motor 452. In this way the steerable instrument 1 can be easily coupled and decoupled from first and second motors 452, 454.

[183] The embodiment of figures 36A, 36B is but one example of how control tube portions 302a(1,3), 302a(2,4) can be coupled to first and second motors 452, 454 in a detachable way, as will be evident to persons skilled in the art.

[194] Figures 36A, 36B, 36C show that steerable instrument 1 has a tube portion 457 located distally from control tube portions 302a(1,3), 302a(2,4) and forming an outer most tube. Tube portion 457 is provided with a plate 459. In practise, first and second motors 452, 454 will be inside a housing. Such a housing is, in this example, provided with a suitable opening through which control tube portions 302a(1,3), 302a(2,4) with plates 456, 457 can pass towards and away from first and second motors 452, 454. Plate 459 and the opening of the housing are then configured such that they lock in a detachable way to one another such that the steerable instrument 1 is locked in both rotation and translation relative to the housing and control tube portions 302a(1,3), 302a(2,4) are correctly aligned with first and second motors 452, 454. The detachable locking can, e,g,, be made by any suitable mechanism, like a clicking or bayonet mechanism.

[195] Another method is to provide the rotatable or slidable tubular interface of the instrument with spur gear teeth 470 or worm drive gear teeth 472, cf. figures 37 and 38. Advantage of this method is that when one wants to control for example two or more steerable sections in an instrument, one can minimize the length of the total coupling. When coaxial hollow axes with attached motors are used, and one needs four or more motors for controlling two or more sections, the total length of the coupling may get rather long. Now radial placement, as shown, can significantly reduce the length of the coupling, and therefore the total length of the instrument.

[196] Figure 26 already shows an example of a coupling between a reusable hand controller and in instrument with one combined sliding and rotating interface. Of course, a comparable method can be used to couple this interface to a robot controller.

[197] It is obvious that also an instrument with two rotating or sliding interfaces can easily be coupled to a hand held actuator that only contains simple additional mechanisms to enable finger control of these interfaces.

[198] It is observed that the invention is not limited as to the number of tubes.

E.g., the instrument may have more tubes than shown in the present examples.

Steering wires 16(i) may have mutually connected or attached separate portions made from the tube material of two or more such tubes, as explained in

WO2017213491. Moreover, the instrument may have other longitudinal control elements made from the tube material and configured to perform another function than explained before, e.g., to lock or unlock a curvature of a portion of the body portion, as explained in WO2023287289.

[199] Though the invasive instrument is shown with one deflectable tip portion, the invention is not restricted to this. Le, the invasive instrument may have multiple deflectable tip portions.

[200] All tubes may, at least in part, be made of at least one of the following set of materials: a biocompatible polymeric material, including polyurethane, polyethylene or polypropylene, stainless steel alloys, cobalt-chromium alloys, shape memory alloys such as Nitinol®, plastic, polymer, composites, or other curable material.

[201] In an embodiment, components of the tubes, including the one or more steering wires 16(1) and longitudinal control elements, result from a material removal technique applied on a wall of the tubes to make suitable material removal patterns, including at least one of photochemical etching, deep pressing, chipping techniques, laser cutting or water cutting. The material removal means can be a laser beam that melts and evaporates material or a water jet cutting beam and this beam can have a width of 0.01 to 2.00 mm, more typically for this application, between 0.015 and 0.04 mm.

[202] The wall thickness of tubes depend on their application. For applications in steerable surgical instruments the wall thickness may be in a range of 0.03-2.0 mm, preferably 0.03-1.0 mm, more preferably 0.05-0.5 mm, and most preferably 0.08-0.4 mm. The diameter of the tubes depend on their application. For applications in steerable surgical instruments the diameter may be in a range of 0.5-20 mm, preferably 0.5-10 mm, more preferably 0.5-6 mm.

The radial play between adjacent tubes may be in range of 0.01 — 0.3 mm.

[203] Features of the invention explained with reference to the preceding figures may be summarized as follows.

[204] A first aspect relates to a steerable instrument with at least one deflectable tip portion (13; 74; 75) at a distal side, the steerable instrument including a first steering wire (16(1); 429) attached to the at least one deflectable tip portion (13; 74, 75), the first steering wire (16(1); 429) being part of at least one tube (3; 102, 103; 121) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a first material removal pattern such that the first steering wire (16(1); 429) extends from a proximal end to a distal end of the steerable instrument, the steerable instrument including a steering unit including a first control tube portion (301a(i); 302a(1,3); 431) coaxially arranged with the at least one tube (3), the first control tube portion (301a(i); 302a(1,3); 431) and the first steering wire (16(1)) being configured such that rotation of the first control tube portion (301a(i); 302a(1,3), 431) causes longitudinal movement of the first steering wire (16(1); 429) in a first longitudinal direction in order to deflect the at least one deflectable tip portion (13; 74; 75) in a first plane.

[205] The first control tube portion (301a(1)) may be provided with a first helical slot (303a(1)), a first sliding element (305a(1)) attached to the first steering wire (16(1)) being provided in the first helical slot (303a(1)) such that rotation of the first control tube portion (301a(i)) causes the longitudinal movement of the first steering wire (16(1)) in the first longitudinal direction.

[206] The first control tube portion may be a serrated first control portion (431), the steerable instrument being provided with a gear (433) which is configured to translate rotation of the first control tube portion (431) into the longitudinal movement of the first steering wire (429).

[207] In a first example, the steerable instrument may include a second steering wire (16(3); 435) attached to the at least one deflectable tip portion (13; 74, 75), the second steering wire (16(3); 435) also being part of the at least one tube (3) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a second material removal pattern such that the second steering wire (16(3); 435) extends from the proximal end to the distal end, the first control tube portion (302a(1,3); 431) and second steering wire (16(3) 435) being configured such that rotation of the first control tube portion (302a(1,3)) causes longitudinal movement of the second steering wire (16(3)) in a second longitudinal direction in order to deflect the at least one deflectable tip portion (13; 74;75)) in the first plane, the second longitudinal direction being opposite to the first longitudinal direction, the second steering wire (16(3); 435) being optionally located at a location 180 degrees tangentially rotated relative to the first steering wire (16(1)).

[208] In the first example, the first control tube portion (302a(1,3)) may be provided with a second helical slot (303a(3)), a second sliding element (305a(3)) attached to the second steering wire (16(3)) being provided in the second helical slot (303a(3)) such that rotation of the first control tube portion (302a(1,3)) causes the longitudinal movement of the second steering wire (16(3)) in the second longitudinal direction.

[209] In the first example, the first control tube portion may be a serrated first control tube portion (431), the steerable instrument being provided with gears (433) which are configured to translate rotation of the serrated first control tube portion (431) into the opposite longitudinal movements of the first and second steering wires.

[210] In the first example, the steerable instrument may include third and fourth steering wires (16(2), 16(4)), respectively, each attached to the at least one deflectable tip portion (13; 74, 75), the third and fourth steering wires (16(2), 16(4)) also being part of the at least one tube (3) and being separated from other parts of the at least one tube (3; 102, 103; 121) by third and fourth material removal patterns, respectively, such that the second and fourth steering wires (16(2), 16(4)) extend from the proximal end to the distal end, the steering unit including a second control tube portion (302(2,4)) coaxially arranged with the at least one tube (3), the second control tube portion (302a(2,4)) and third and fourth steering wires (16(2), 16(4)) being configured such that rotation of the second control tube portion (302(2,4))) causes longitudinal movements of the third and fourth steering wires (16(2), 16(4)) in opposite longitudinal directions in order to deflect the at least one deflectable tip portion (13; 74; 75)) in a second plane perpendicular to the first plane, the first, second, third and fourth steering wires (16(1), 16(2), 16(3), 16(4)) being optionally located at equidistant locations as seen in the tangential direction of the steerable instrument.

[211] Then the second control tube portion (302(2,4)) may be provided with third and fourth helical slots (303a(2), 303a(4)), a third sliding element (305a(2)) attached to the third steering wire (16(2)) being provided in the third helical slot (303a(2)) and a fourth sliding element (305a(4)) attached to the fourth steering wire (16(4)) being provided in the fourth helical slot (303a(4)) such that rotation of the second control tube portion (302(2,4))) causes the longitudinal movements of the third and fourth steering wires (16(2), 16(4)) in opposite longitudinal directions.

[212] Alternatively, then the second control tube portion may be a serrated second control tube portion, the steerable instrument being provided with gears which are configured to translate rotation of the serrated second control tube portion into the opposite longitudinal movements of the third and fourth steering wires.

[213] The steerable instrument may include a further tube (4; 104; 203) coaxially arranged between the at least one tube (3; 101, 102; 121) and the first control tube portion (301a(1)), the further tube being provided with a first longitudinal slot (309(1)), the first sliding element (305a(1)) being attached to the first steering wire (16(1)) through the first longitudinal slot (309(1)).

[214] Then the first sliding element may include a first sliding notch (305a(1)) and the further tube may include a second sliding notch (307(1)) attached to both the first sliding notch (305a(1)) and to the first steering wire (16(1)).

[215] In the first example, the steerable instrument may include a further tube (4; 104; 203) coaxially arranged between the at least one tube (3; 101, 102; 121) and the first control tube portion (302a(1,3)), the further tube being provided with a first longitudinal slot (309(1)) and a second longitudinal slot (309(3)), the first sliding element (305a(1)) being attached to the first steering wire (16(1)) through the first longitudinal slot (309(1)), the second sliding element (305a(3)) being attached to the second steering wire (16(3)) through the second longitudinal slot (309(3)).

[216] Then the first sliding element may include a first sliding notch (305a(1)), the further tube including a second sliding notch (307(1)) attached to both the first sliding notch (305a(1)) and to the first steering wire (16(1)), the second sliding element including a third sliding notch (305a(3)), the further tube including a fourth sliding notch (307(3)) attached to both the third sliding notch (305a(3)) and to the second steering wire (16(3)).

[217] The steerable instrument may include a first component (321) attached to the further tube (203) at a distal side of the first control tube portion (301a(i); 302a(1,3)) and a second component (323) attached to the further tube (203) at a proximal side of the first control tube portion (301a(i); 302a(1,3)) such as to block longitudinal movement of the first control tube portion (301a(i); 302a(1,3)).

[218] The steerable instrument may include a longitudinal slider (331a) provided with a third helical slot (335a), a third sliding element (333a) attached to the first control tube portion (301a(i); 302a(1,3)) being provided in the third helical slot (335a) such that longitudinal movement of the longitudinal slider (331a) causes rotation of the first control tube portion (301a(i); 302a(1,3)).

[219] The steerable instrument may include a further tube (4; 104; 203) coaxially arranged between the at least one tube (3; 101, 102; 121) and the first and second control tube portions (302a(1,3); 302(2,4)), the further tube being provided with a first longitudinal slot (309(1)), a second longitudinal slot (309(3)), a third longitudinal slot (309(2)) and a fourth longitudinal slot (309(4)), the first sliding element (305a(1)) being attached to the first steering wire (16(1)) through the first longitudinal slot (309(1)), the second sliding element (305a(3)) being attached to the second steering wire (16(3)) through the second longitudinal slot (309(3)), the third sliding element (305a(2)) being attached to the third steering wire (16(2)) through the third longitudinal slot (309(2)), the fourth sliding element (305a(4)) being attached to the second steering wire (16(3)) through the fourth longitudinal slot (309(4)).

[220] The first sliding element may include a first sliding notch (305a(1)), the further tube including a second sliding notch (307(1)) attached to both the first sliding notch (305a(1)) and to the first steering wire (16(1)), the second sliding element including a third sliding notch (305a(3)), the further tube including a fourth sliding notch (307(3)) attached to both the third sliding notch (305a(3)) and to the second steering wire (16(3)), the third sliding element including a fifth sliding notch (305a(2)), the further tube including a six sliding notch (307(2)) attached to both the fifth sliding notch (305a(2)) and to the third steering wire (16(2)), the fourth sliding element including a seventh sliding notch (305a(4)), the further tube including an eighth sliding notch (307(4)) attached to both the seventh sliding notch (305a(4)) and to the fourth steering wire (16(4)).

[221] The steerable instrument may include a first component (321) attached to the further tube (203) at a distal side of the first control tube portion (302a(1,3)), a second component (323) attached to the further tube (203) at a proximal side of the first control tube portion (302a(1,3)), a third component (323) attached to the further tube (203) at a distal side of the second control tube portion (302a(2,4)), a fourth component (327) attached to the further tube (203) at a proximal side of the second control tube portion (302a(2,4)) such as to block longitudinal movements of the first and second control tube portions (302a(1,3), 302a(2,4)).

[222] The steerable instrument may include a longitudinal slider (33 1a) connected to the first control tube portion (302a(1,3)) such that longitudinal movement of the longitudinal slider (331a) causes rotation of the first control tube portion (302a(1,3)), the steerable instrument including a slider (349a) connected to the second control tube portion (302a(2,4)) such that rotation of the slider (349a) causes rotation of the second control tube portion (302a(2,4)), and including a connecting component (359) connecting the longitudinal slider (331a) and the slider (349a) such that when the connecting component (359) moves in the longitudinal direction it causes longitudinal movement of the longitudinal slider (331a) and when connecting component (359) rotates it causes rotational movement of the slider (349a), wherein the connecting component (359) may have a tube- shape.

[223] The slider (349a) may be provided with a fifth longitudinal slot (351a) accommodating a ninth sliding notch (353a), the longitudinal slider (331a) may be provided with a third helical slot (335a) and a tangential slot (355a) accommodating a tenth sliding notch (357a), a third sliding element (333a) attached to the first control tube portion (301a(i); 302a(1,3)) being provided in the third helical slot (33 5a), the connecting component (359) being either attached to both the tenth sliding notch (357a) and to the ninth sliding notch (353a) while the slider (349a) is attached to the second control tube portion (302a(2,4)), or attached to both the tenth sliding notch (35724) and to the slider (349a) while the ninth sliding notch (353a) is attached to the second control tube portion (302a(2,4)).

[224] The steerable instrument may include a driving element (33 1a; 359; 447) connected to the first control tube portion (302a(1,3)) such that longitudinal movement of the driving element (359; 447) causes rotation of the first control tube portion (302a(1,3)) in a first tangential direction, the driving element (359; 447) being connected to the second control tube portion (302a(2,4)) such that longitudinal movement of the drive element (359; 447) causes rotation of the second control tube portion (302a(2,4)) in a second tangential direction opposite to the first tangential direction, the driving element (359; 447) being also connected to the first and second control tube portions (302a(1,3), 302a(2,4)) such that a tangential rotation of the drive element (359; 447) causes tangential rotation of both the first and second control tube portions (302a(1,3), 302a(2,4)) in the same direction.

[225] The driving element (33 1a) may comprise a third helical slot (3352), a third sliding element (333a) attached to the first control tube portion (302a(1,3)) being provided in the third helical slot (3352), and may comprise a fourth helical slot (335a), a fourth sliding element (333a) attached to the second control tube portion (302a(2,4)) being provided in the fourth helical slot (335a).

[226] The driving element may comprise a tube-shaped driving element (447) having a serrated opening accommodating a gear (450) and configured to rotate the gear (450) when tube-shaped driving element (447) moves in the longitudinal direction, the gear (450) being configured to rotate serrated first and second control tube portions (443, 445) in opposite tangential directions when it rotates.

[227] In a second aspect the invention relates to a steerable instrument with at least one deflectable tip portion (13; 74; 75) at a distal side, the steerable instrument including a first steering wire (16(1); 429) attached to the at least one deflectable tip portion (13; 74, 75), the first steering wire (16(1); 429) being part of at least one tube (3; 102, 103; 121) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a first material removal pattern such that the first steering wire (16(1); 429) extends from a proximal end to a distal end of the steerable instrument, wherein longitudinal movement of the first steering wire (16(1); 429) causes deflection of the at least one deflectable tip portion (13; 74,75)) in a first plane, the steerable instrument including at least one longitudinal control element (421(1,2)) and a steering unit including a first control tube portion (301a(i); 302a(1,3); 431) coaxially arranged with the at least one tube (3), the first control tube portion (301a(1); 302a(1,3); 431) and the at least one longitudinal control element (421(1,2)) being configured such that rotation of the first control tube portion (301a(i1); 302a(1,3)) causes longitudinal movement of the at least one longitudinal control element (421(1,2)) such as to control a function of the steerable instrument, such as locking or unlocking a bent portion of the instrument, or operating a tool at the at least one deflectable tip portion.

[228] In this second aspect a first longitudinal control element (421(1,2)) may be connected to the first control tube portion (302a(1); 302a(1,3)) at its proximal end and may be connected to the first steering wire (16(1)) and to a second steering wire (16(2)) via a gear arrangement (401(1,2); 401(1,2), 403(1), 403(2)) at its distal end, the first longitudinal control element (421(1,2)) and gear arrangement (401(1,2); 401(1,2), 403(1), 403(2)) being configured such that a longitudinal movement of the first longitudinal control element (421(1,2)) results in longitudinal movements of both the first and second steering wires (16(1), 16(2)) in the same longitudinal direction, the gear arrangement being configured to compensate path length differences between the first and second steering wires (16(1), 16(2)).

[229] The invention relates to an invasive instrument including a steerable instrument of the first or second aspect.

[230] The invention relates to a control unit and a steerable instrument, wherein the control unit includes a first motor (452) configured to be detachably coupled to the first control tube portion (302a(1,3)).

[231] The invention relates to a control unit and a steerable instrument, wherein the control unit includes a first motor (452) and a second motor (454), the first motor (452) being configured to be detachably coupled to the first control tube portion (302a(1,3)) and the second motor (454) being configured to be detachably coupled to the second control tube portion (302a(2,4)).

[232] In an invasive instrument including a manually operable control unit and a steerable instrument, the manually operable control unit may be configured to allow a user to perform manual movements of the connecting component (359) in both longitudinal and tangential directions with a finger.

[233] In an invasive instrument including a manually operable control unit and a steerable instrument, the manually operable control unit may be configured to allow a user to perform manual movements of the driving element (359) in both longitudinal and tangential directions with a finger.

[234] The manually operable control unit may be detachably coupled to the steerable instrument.

General remark

[235] The examples and embodiments described herein serve to illustrate rather than to limit the invention. The person skilled in the art will be able to design alternative embodiments without departing from the scope of the claims. Reference numbers placed in parentheses in the claims shall not be interpreted to limit the scope of the claims. Items described as separate entities in the claims or the description may be implemented as a single or multiple hardware items combining the features of the items described.

[236] It is to be understood that the invention is limited by the annexed claims and its technical equivalents only. In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".

Claims

Conclusions

1. A steerable instrument having at least one deflectable tip section (13; 74; 75) on a distal side, the steerable instrument comprising a first steering wire (16(1); 429) connected to the at least one deflectable tip section (13; 74; 75), the first steering wire (16(1); 429) being part of at least one tube (3; 102, 103; 121) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a first material removal pattern such that the first steering wire (16(1); 429) extends from a proximal end to a distal end of the steerable instrument, the steerable instrument comprising a steering unit comprising a first steering tube section (301a(i); 302a(1, 3); 431) coaxially disposed with the at least one tube (3), wherein the first control tube portion (301a(i); 302a(1, 3); 431) and the first steering wire (16(1)) are configured such that rotation of the first control tube portion (301a(i); 302a(1, 3); 431) causes longitudinal movement of the first steering wire (16(1); 429) in a first longitudinal direction to deflect the at least one deflectable tip portion (13; 74; 75) in a first plane.

2. The steerable instrument of claim 1, wherein the first steering tube portion (301a(i)) includes a first spiral slot (303a(1)), a first sliding member (305a(1)) attached to the first steering wire (16(1)) being provided in the first spiral slot (303a(1)) such that rotation of the first steering tube portion (301a(i)) causes the longitudinal movement of the first steering wire (16(1)) in the first longitudinal direction.

The steerable instrument of claim 1, wherein the first steering tube portion is a serrated first steering portion (431), the steerable instrument comprising a transmission (433) configured to translate the rotation of the first steering tube portion (431) to the longitudinal movement of the first steering wire (429).

The steerable instrument of claim 1, wherein the steerable instrument comprises a second steering wire (16(3); 435) attached to the at least one deflectable tip portion (13; 74; 75), the second steering wire (16(3); 435) also forming part of the at least one tube (3) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a second material removed pattern such that the second steering wire (16(3); 435) extends from the proximal end to the distal end, the first steering tube portion (302a(1,3); 431) and the second steering wire (16(3); 435) being configured such that rotation of the first steering tube portion (302a(1,3)) causes the longitudinal movement of the second steering wire (16(3)) in a second longitudinal direction to move the at least one deflectable tip portion (13; 74; 75) in the first plane, wherein the second longitudinal direction is opposite to the first longitudinal direction and wherein the second control wire (16(3); 435) is optionally located at a location rotated 180 degrees tangentially relative to the first control wire (16(1)).

5. The steerable instrument of claim 4, wherein the first steering tube portion (302a(1, 3)) is provided with a second spiral slot (303a(3)), a second sliding member (305a(3)) attached to the second steering wire (16(3)) is provided in the second spiral slot (303a(3)) so that rotation of the first steering tube portion (302a(1, 3)) causes the longitudinal movement of the second steering wire (16(3)) in the second longitudinal direction.

6. The steerable instrument of claim 4, wherein the first steering tube portion is a serrated first steering portion (431), the steerable instrument including a transmission (433) configured to translate the rotation of the serrated first steering tube portion (431) to the opposing longitudinal movements of the first and second steering wires.

7. A steerable instrument according to any one of claims 4 to 6, wherein the steerable instrument comprises third and fourth steering wires (16(2), 16(4)), respectively, each connected to the at least one deflectable tip portion (13; 74; 75), the third and fourth steering wires (16(2), 16(4)) also being part of the at least one tube (3) and being separated from other parts of the at least one tube (3; 102, 103; 121) by third and fourth material removed patterns, respectively, such that the second and fourth steering wires (16(2), 16(4)) extend from the proximal end to the distal end, the steering unit comprising a second steering tube portion (302(2, 4)) coaxially disposed with the at least one tube (3), the second steering tube portion (302(2, 4)) and third and fourth steering wires (16(2), 16(4)) are configured such that rotation of the second steering tube portion (302(2, 4)) causes longitudinal movements of the third and fourth steering wires (186{2), 16(4)) in opposite longitudinal directions to deflect the at least one deflectable tip portion (13; 74; 75) in a second plane perpendicular to the first plane, the first, second, third and fourth steering wires (161), 16(2), 16(3), 16(4)) optionally being located at equidistant locations as viewed in the tangential direction of the steerable instrument.

8. The steerable instrument of claim 7, wherein the second steering tube portion (302(2, 4)) comprises third and fourth spiral slots (303a(2), 303a(4)), a third sliding member (305a(2)) attached to the third steering wire (16(2)) is provided in the third spiral slot (303a(2)), and a fourth sliding member (305a(4)) attached to the fourth steering wire (16(4)) is provided in the fourth spiral slot (303a(4)), so that rotation of the second steering tube portion (302(2, 4)) causes the longitudinal movements of the third and fourth steering wires (16(2), 16(4)) in opposite longitudinal directions.

9. The steerable instrument of claim 7, wherein the second steering tube portion is a serrated second steering tube portion, the steerable instrument including a transmission configured to translate the rotation of the second serrated steering tube portion to the opposing longitudinal movements of the third and fourth steering wires.

10. A steerable instrument according to claim 2, wherein the steerable instrument further comprises a tube (4; 104; 203) coaxially disposed between the at least one tube (3; 101, 102; 121) and the first steering tube portion (301a(i)), the further tube having a first longitudinal slot (309(1)), the first sliding member (305a(1)) being attached to the first steering wire (16(1)) via the first longitudinal slot (309(1)).

11. A steerable instrument as claimed in claim 10, wherein the first sliding member comprises a first sliding notch (305a(1)) and the further tube comprises a second sliding notch (307(1)) attached to both the first sliding notch (305a(1)) and the first steering wire (16(1)).

12. A steerable instrument according to claim 5, wherein the steerable instrument further comprises a tube (4; 104; 203) coaxially disposed between the at least one tube (3; 101, 102; 121) and the first steering tube portion (302a(1, 3)), the further tube having a first longitudinal slot (309(1)) and a second longitudinal slot (309(3)), the first sliding element (305a(1)) being attached to the first steering wire (16(1)) via the first longitudinal slot (309(1)), the second sliding element (305a(3)) being attached to the second steering wire (16(3)) via the second longitudinal slot (309(3)).

13. A steerable instrument as claimed in claim 12, wherein the first sliding element comprises a first sliding notch (305a(1)), the further tube comprises a second sliding notch (307(1)) attached to both the first sliding notch (305a(1)) and the first steering wire (16(1)), the second sliding element comprises a third sliding notch (305a(3)), the further tube comprises a fourth sliding notch (307(3)) attached to both the third sliding notch (305a(3)) and the second steering wire (16(3)).

A steerable instrument according to any one of claims 10 to 13, comprising a first part (321) attached to the further tube (203) at a distal side of the first steering tube portion (301a(i); 302a(1, 3)) and a second part (323) attached to the further tube (203) at a proximal side of the first steering tube portion (301a(i); 302a(1, 3)) such that longitudinal movement of the first steering tube portion (301a(i); 302a(1, 3)) is blocked.

A steerable instrument according to any preceding claim, comprising a longitudinal slide (3313) having a third spiral slot (335a), a third sliding element (333a) attached to the first steering tube portion (301a(i); 302a(1, 3))

which is provided in the third spiral slot (3353) such that the longitudinal movement of the longitudinal slide (331a) causes the rotation of the first control tube portion (301a(j); 302a(1, 3)).

16. A steerable instrument according to claim 8, wherein the steerable instrument further comprises a tube (4; 104; 203) coaxially disposed between the at least one tube (3; 101, 102; 121) and the first and second steering tube portions (302a(1, 3); 302(2, 4)), the further tube comprising a first longitudinal slot (309(1)), a second longitudinal slot (309(3)), a third longitudinal slot (309(2)) and a fourth longitudinal slot (309(4)), the first sliding element (305a(1)) being attached to the first steering wire (16(1)) via the first longitudinal slot (309(1)), the second sliding element (305a(3)) being attached to the second steering wire (16(3)) via the second longitudinal slot (309(3)), the third sliding element (305a(2)) is attached to the third control wire (16(2)) via the third longitudinal slot (309(2)) and the fourth sliding element (305a(4)) is attached to the second control wire (16(3)) via the fourth longitudinal slot (309(4)).

17. A steerable instrument according to claim 18, wherein the first sliding element comprises a first sliding notch (305a(1)), the further tube comprises a second sliding notch (307(1)) secured to both the first sliding notch (305a(1)) and the first steering wire (16(1)), the second sliding element comprises a third sliding notch (305a(3)), the further tube comprises a fourth sliding notch (307(3)) secured to both the third sliding notch (305a(3)) and the second steering wire (16(3)), the third sliding element comprises a fifth sliding notch (305a{2)), the further tube comprises a sixth sliding notch (307(2)) secured to both the fifth sliding notch (305a(2)) and the third steering wire (16(2)), and the fourth sliding element comprises a seventh sliding notch (305a(2)) and the fifth steering notch (305a(2)) and the third steering wire (16(2)). notch (305a(4)), the further tube includes an eighth sliding notch (307(4)) which is attached to both the seventh sliding notch (305a(4)) and to the fourth control wire (16(4)).

A steerable instrument according to any one of claims 16 to 17, comprising a first part (321) attached to the further tube (203) at a distal side of the first steer tube portion (302a(1, 3)), a second part (323) attached to the further tube (203) at a proximal side of the first steer tube portion (302a(1, 3)), a third part (323) attached to the further tube (203) at a distal side of the second steer tube portion (302a(2, 4)), a fourth part (327) attached to the further tube (203) at a proximal side of the second steer tube portion (302a(2, 4)), so as to block longitudinal movements of the first and second steer tube portions (302a(1, 3), 302a(2, 4}).

A steerable instrument according to any one of claims 8 or 16 to 18, comprising a longitudinal slide (331a) connected to the first steering tube portion (302a(1, 3)) such that longitudinal movement of the longitudinal slide (3314) causes rotation of the first steering tube portion (302a(1, 3)), the steerable instrument comprising a slide (3493) connected to the second steering tube portion (302a(2, 4)) such that rotation of the slide (349a) causes rotation of the second steering tube portion (302a(2, 4)) and a connecting member (359) connecting the longitudinal slide (3314) and the slide (349a) such that when the connecting member (359) moves in the longitudinal direction, it causes longitudinal movement of the longitudinal slide (331a) and when the connecting member (359) rotates, this provides the rotational movement of the slide (349a), whereby the connecting part (359) can have a tubular shape.

20. The steerable instrument of claim 19, wherein the slide (349a) includes a fifth longitudinal slot (3514) accommodating a ninth sliding notch (3534), the longitudinal slide (3314) includes a third spiral slot (335a) and a tangential slot (3553) accommodating a tenth sliding notch (3574), a third sliding member (3334) attached to the first steering tube portion (301a(i); 302a(1, 3)) provided in the third spiral slot (3354), the connecting member (359) being attached to either both the tenth sliding notch (3573) and the ninth sliding notch (3533), while the slide (349a) is attached to the second steering tube portion (302a(2, 4)), or is attached to both the tenth sliding notch (357a) and the slide (3493), while the ninth sliding notch (3534) is attached to the second control tube portion (302a(2,

4).

A steerable instrument according to any one of claims 8, 9 or 16 to 18, comprising a drive member (3313; 359; 447) connected to the first steering tube portion (302a(1, 3)) such that longitudinal movement of the drive member (359; 447) causes rotation of the first steering tube portion (302a{1, 3)) in a first tangential direction, the drive member (359; 447) connected to the second steering tube portion (302a(2, 4)) such that longitudinal movement of the drive member (359; 447) causes rotation of the second steering tube portion (302a(2, 4}) in a second tangential direction opposite to the first tangential direction, the drive member (359; 447) also connected to the first and second steering tube portions (302a(1, 3); 302(2, 4)), such that tangential rotation of the drive element (359; 447) causes tangential rotation of both the first and second control tube portions (302a(1, 3); 302(2, 4)) in the same direction.

A steerable instrument according to claim 21, being dependent on any one of claims 8 or 16 to 18, wherein the drive member (3314) comprises a third spiral slot (3353), a third sliding member (3333) attached to the first steering tube portion (302a(1, 3)) being provided in the third spiral slot (335a), and a fourth spiral slot (335a), a fourth sliding member (333a) attached to the second steering tube portion (302a(2, 4)) being provided in the fourth spiral slot (3353).

23. A steerable instrument as claimed in claim 21 when dependent on claim 9, wherein the drive element comprises a tubular drive element (447) having a serrated opening housing a gear (450) and configured to rotate the gear (450) as the tubular drive element (447) moves in the longitudinal direction, the gear (450) being configured to rotate the serrated first and second steering tube portions (443, 445) in opposite tangential directions as it rotates.

24. A steerable instrument having at least one deflectable tip section (13; 74; 75) on a distal side, the steerable instrument comprising a first steering wire (16(1); 429) connected to the at least one deflectable tip section (13; 74; 75), the first steering wire (16(1); 429) being part of at least one tube (3; 102, 103; 121) and being separated from other parts of the at least one tube (3; 102, 103; 121) by a first material removed pattern such that the first steering wire (16(1); 429) extends from a proximal end to a distal end of the steerable instrument, wherein longitudinal movement of the first steering wire (16(1); 429) causes deflection of the at least one deflectable tip section (13; 74; 75). 75) in a first plane, the steerable instrument comprising at least one longitudinal control element (421(1, 2) and a control unit comprising a first control tube portion (301a(i); 302a(1, 3); 431) coaxially disposed with the at least one tube (3), the first control tube portion (301a(i); 302a(1, 3); 431) and the at least one longitudinal control element (421(1, 2)) being configured such that rotation of the first control tube portion (301a(i); 302a(1, 3)) causes longitudinal movement of the at least one longitudinal control element (421(1, 2)) to control a function of the steerable instrument, such as locking or unlocking a curved portion of the instrument, or operating a tool on the at least one deflectable tip portion.

25. The steerable instrument of claim 24, wherein a first longitudinal control element (421(1, 2)) is connected to the first steering tube portion (302a(1); 302a(1, 3)) at its proximal end and is connected to the first steering wire (16(1)) and to a second steering wire (16(2)) via a transmission assembly (401(1, 2), 401(1, 2), 401(3), 403(2)) at its distal end, the first longitudinal control element (421(1, 2) and the transmission assembly (401(1, 2), 401(1, 2), 401(3), 403(2)) being configured such that longitudinal movement of the first longitudinal control element (421(1, 2) results in longitudinal movements of both the first and second steering wires (16(1), 16(2)) in the same longitudinal direction, the transmission assembly being configured to compensate for the path length differences between the first and second control wires (16(1), 16(2)).

A steerable instrument according to any preceding claim, wherein the at least one tube (3; 102, 103; 121) comprises an annular end portion (314) at its distal end to which the first steering wire (16(1)) is attached.

27. A steerable instrument according to any preceding claim, wherein parts of the instrument are made of at least one of the following set of materials: a biocompatible polymeric material, comprising polyurethane, polyethylene or polypropylene, stainless steel alloys, cobalt and chromium alloys, shape memory alloy such as Nitinol®, plastic, polymer, composites or other hardenable material.

28. An invasive instrument comprising a steerable instrument according to any preceding claim.

An invasive instrument comprising a control unit and a steerable instrument according to any of claims 1 to 28, wherein the control unit comprises a first motor (452) configured to be removably coupled to the first steering tube portion (302a(1, 3)).

An invasive instrument comprising a control unit and a steerable instrument according to any of claims 7 to 9, 16 to 23, wherein the control unit comprises a first motor (452) and a second motor (454), the first motor (452) configured to be removably coupled to the first control tube portion (302a(1, 3)) and the second motor (454) configured to be removably coupled to the second control tube portion (302a(2, 4)).

An invasive instrument comprising a manually operated control unit and a steerable instrument according to any of claims 19 or 20, wherein the manually operated control unit is configured to enable a user to perform manual movements of the connecting member (359) in both the longitudinal and tangential directions with a finger.

An invasive instrument comprising a manually operable control unit and a steerable instrument according to any of claims 21 or 22, wherein the manually operable control unit is configured to enable a user to perform manual movements of the actuating element (359) in both the longitudinal and tangential directions with a finger.

33. The invasive instrument of claim 31 or 32, wherein the manually operable control unit is detachably coupled to the steerable instrument.