HK1191582A - Dermally affixed device for intravenous access - Google Patents

Description

Skin fixation device for intravenous access

Technical Field

The present invention relates generally to intravenous injection and diagnostic devices, and more particularly to devices having a contact surface for attachment to the skin of a patient and an intravenous cannula for introducing injection fluid or withdrawing blood.

Background

Intravenous infusion sets are widely used in patient care, but their size and complexity make their use largely restricted to dedicated equipment, and mobile use is almost precluded. In recent years, ambulatory use of subcutaneous infusion devices has begun to be in the care of diabetes for delivering insulin, but similar devices do not meet the need for safe and convenient ambulatory use for intravenous infusion without reducing the patient's normal daily activities. The main drawback for mobile use is that they operate with a connection tube to an intravenous catheter and are too large and heavy for the patient to wear directly, so they will be stationary or attached to a stand.

For individual health care, it will be important to monitor the levels of endogenous analytes and drugs over a period of hours to days. This requires frequent blood sampling and therefore can generally only be done at dedicated facilities or hospitals. The patient typically has to remain at the device for the entire duration of the treatment process, causing inconvenience and higher costs. This prevents the widespread use of this technology in personalized medicine.

Disclosure of Invention

The object of the present invention is to overcome the problems of the mobile use of current intravenous injection systems or the problem of a series of blood samples for analyte determination by combining concise and improved individual device components, and the cooperation of these components achieves the desired compactness, resulting in a smaller size and weight, and therefore a safe attachment to the skin.

More specifically, the object of the present invention is a solution for intravenous delivery of injection fluid into a patient or for removal of blood from a patient by means of a device which does not require long connecting tubes to the intravenous catheter and which can be worn by the user by adhering directly to the skin at the site of intravenous access, enabling ambulatory use without interfering with normal daily activities.

According to the present invention, the above problem is solved by an intravenous access device having the specific features of claim 1.

An intravenous access device of the present application for introducing an injection fluid into a patient or removing blood through an intravenous catheter includes: a port at the outer end of the intravenous catheter, the port having a septum; a connection element having an adhesive surface for fixed attachment to the skin, and means for positioning and fixing the port and the injection or blood sampling unit relative to each other and thus piercing the septum of the port by means of a connection cannula ensuring the free passage of injection fluid or blood between the injection or blood sampling unit and the intravenous catheter. The port, the connecting element and the injection or blood sampling unit have means for a simple, secure and functionally safe assembly. The connecting cannula has a tip configured to pierce the septum of the port and sized to introduce an injection fluid into the patient or remove blood therefrom. Typically, the piercing of the septum of the port by the connecting cannula will be performed by structural elements and the start of the infusion and/or blood sampling process will be automatically driven after assembly.

In a preferred embodiment, the device of the invention has a connection cannula which is firmly positioned with respect to the housing and the pump of the infusion or blood sampling unit. This enables a simpler construction and higher performance reliability than flexible connections.

The present invention extends the advantages of a miniature infusion pump (patch pump) directly adhered to the skin for subcutaneous injection of a drug to intravenous access within a single device (without interfering with the connection tubing). The invention also allows easy ambulatory sampling of blood, for example for pharmacokinetics or for determining circadian rhythm, and can be used in hospital settings for determining the concentration of an analyte, such as glucose, by continuous small blood draws, which is important for the treatment of children or in ICU. In a preferred embodiment, the injection or blood sampling unit has a syringe pump, preferably a barrel bent into the shape of a segment of a solenoid, resulting in a significantly reduced footprint (footprint) and suitable reduction of the overall size. In an alternative preferred embodiment, the injection device of the invention has a flexible reservoir integrated with the connecting cannula for containing the injection fluid, the flexible reservoir being preferably manufactured by blow-fill-seal technology, and the delivery of the injection fluid being achieved by controlled compression of the flexible reservoir.

The following definitions are used in this specification:

an "adhesive contact surface" for temporary wear on the skin is made of a material with strong adhesive properties, stretchability and minimal allergenicity. Such an adhesive layer is fixed to the base of the device and preferably the surface of the adhesive layer which is fixed to the skin is significantly larger than the surface of the adhesive layer which is fixed to the base of the device. This can be achieved, for example, by having the adhesive layer extend beyond the surface of the base of the device, or preferably by using an adhesive surface for the skin that is shaped like the surface of the base of the device or only slightly larger than the surface of the base of the device, but that is fixed on the surface of the base of the device in such a way that the outer annular area is not fixed on the base of the device. Such a design is described in EP 0825882.

By "analyte" is meant any endogenous or exogenous substance, the concentration of which can be used to diagnose the health, organ function, metabolic state, or drug metabolizing capacity of an individual. Examples of endogenous substances are glucose, lactic acid, oxygen, creatinine, etc. Examples of exogenous substances are drugs, metabolites of such drugs, diagnostic substances (e.g. insulin) etc.

A "blood sampling unit" is a functional element for collecting a blood sample for on-line determination of an analyte by, but not limited to, biochemical, immunological, HPLC or LC/MS/MS methods, either inside or outside the device. Usually, it comprises a pump which allows the aspiration of the fluid, for example a syringe pump, which is connected to the connecting cannula. For external analysis, samples can be collected in separate containers or in a continuous cavity (e.g., a tube), taking steps to minimize mixing of samples taken at different times. This can be achieved, for example, by introducing an air segment or immiscible fluid into the withdrawn blood, thereby creating separate samples within the continuous cavity.

A "connecting cannula" is a hollow needle having an outer diameter of less than 1mm which is connected to an injection or blood sampling unit and has a tip which is configured and dimensioned to readily penetrate the septum of the port. The insertion into the septum of the port can be achieved by pressing the injection or blood sampling unit against the port, and the insertion into the septum of the port is guided and reinforced by the connecting element.

A "connection element" is a transition between the port and the injection or blood sampling unit. It has a flat or slightly concave base for attachment to the skin, e.g. the forearm, and it also has means for positioning it over the stoma and for securing the stoma, e.g. by a screw mechanism. The connecting element is attached and fixed to the patient's skin by means of an adhesive contact surface on its base, so that the mouth remains firmly attached as well. The connection element also has means for positioning the injection or blood sampling unit relative to the port such that the connection cannula is aligned with the septum of the port, and by pressing the injection or blood sampling unit against the connection element of the holding port, the connection cannula penetrates the septum of the port, thus fluidly connecting the injection or blood sampling unit to the intravenous catheter. Preferably, the means for fixing the injection or blood sampling unit on the connecting element are arranged such that the connection is effected and re-effected automatically after mutual pressing, and the disconnection for detachment is effected manually.

"delivery of injection fluid" includes both relatively rapid infusion (bolus) and relatively slow introduction (also known as infusion or instillation) of liquid into the body.

"drive and control appliance" includes all the necessary mechanical, electronic and software elements for all the necessary functions of the device and the like, but is not limited to: the delivery of injection fluid to the patient or for the withdrawal of blood from the patient in accordance with internal or external signals, in order to initiate, control and measure the correct function of the device, the supply and control of measuring instruments for the analyte and the conversion of sensor signals into analyte measurements, the online or batch storage, display and transmission of the analyte measurements, the preferably wireless interaction with an external device, and the emission of a warning signal when the device is not functioning correctly or when the analyte measurements are not within a predetermined range.

An "injection unit" is a functional element for delivering injection fluid, typically comprising a reservoir, a pump, drive and control means and a connecting cannula. In some types of pumps (e.g., syringe pumps or pressurized systems), the reservoir is an integral part of the pump mechanism, while in other types (e.g., peristaltic pumps or reciprocating piston pumps), it is a separate body. The reservoir can be pre-filled with the injection fluid or filled just prior to use. Preferably, a pump type capable of compact construction and shape (capable of being conveniently worn) is attached to the skin of the patient, such as a syringe pump, the barrel of which is bent into the shape of a segment of a spiral tube, or a pump with a flexible reservoir through which compressed gas from a gas generating chamber causes positive displacement of the injected fluid.

An "intravenous catheter" is a small flexible tube composed of a synthetic polymer that is typically placed in a peripheral vein, preferably on the arm, for administration or withdrawal of blood. The catheter is introduced into the vein through a guiding needle or guide wire (stylet) which is then removed, while the catheter remains in place. The end of the catheter outside the vein terminates in the cavity of the port, and the port forms an integral part of the system for intravenous placement of the catheter and removal of the introducer needle or guide wire.

"measuring instrument for an analyte" is a functional element for determining the concentration of an analyte and means, but is not limited to, any on-line analytical system, such as an electrochemical, optical, thermometric, piezoelectric or magnetic measurement system.

The "port" at the outer end of the intravenous catheter comprises a housing with a cavity and one or more septa for connecting the intravenous catheter with an injection or blood sampling unit via a connecting cannula. Preferably, the port has a septum for withdrawing the introducer needle or guide wire after the intravenous catheter has been introduced into the vein, the septum being closed after removal.

A "septum" is a stopper made of a natural or synthetic rubber type material that can be pierced by a cannula or wire in a contamination-free and sealing manner, and closes itself when the cannula or wire is removed, and forms a seal again.

The term "intravenous inlet" is used for the connection between an inserted intravenous catheter and an external unit for injecting fluid into or removing blood from a vein through the catheter.

Drawings

Exemplary embodiments of the invention will now be described with reference to the accompanying drawings, in which:

fig. 1 is a schematic cross-sectional view of an intravenous access port at the outer end of an intravenous catheter for intravenous delivery of an injection fluid to a patient or for removal of blood from a patient.

Fig. 2 is a schematic top cross-sectional view of a connection element connecting an injection or blood sampling unit with a port.

Fig. 3 is a schematic cross-sectional view of a device for intravenous delivery of injection fluid into a patient with assembled port, connecting element and injection unit.

Fig. 4 is a schematic, horizontal cross-sectional view of an alternative embodiment of a device for intravenous delivery of injection fluid into a patient having an assembled port, connecting element and injection unit.

Detailed Description

At the outer end of the intravenous catheter 3, the intravenous access port shown in fig. 1 comprises a housing 1, the housing 1 having a cavity 2. The catheter is introduced into the vein through the introducer needle 4 (shown here as partially withdrawn) which is then withdrawn by fully withdrawing it through the septum 5 while the catheter remains in place. The introducer needle is configured such that visual confirmation of successful vascular access can be achieved (e.g., by using a grooved needle). The handle 6, which facilitates the introduction of the intravenous port, comprises two elements (shown disassembled during withdrawal of the introducer needle 4) and is arranged so that its sharp bevel is protected after the introducer needle has been removed for added safety. The cavity 2 has a further septum 7 for access to a connected cannula. The housing 1 of the port has a rim 8, which rim 8 is intended to be attached to a connection element intended to be connected between the port and an injection or blood sampling unit. The connecting element will be described below with reference to fig. 2.

In an alternative embodiment, which is preferably used in the case where an intravenous catheter is introduced intravenously at a body location (e.g., the curvature of an arm) that is not suitable for placement of the device directly over the catheterization site, a handle having a stable platform of soft and flexible material is attached to the catheter between its tip and the mouth (not shown). This facilitates proper placement of the catheter and the port and helps minimize movement of the catheter within the vessel.

In detail a, the indwelling tip of the intravenous catheter is shown in a preferred configuration to avoid direct contact of the injected fluid with the vessel wall, which may cause local irritation. The catheter is preformed to take a helical shape with a hole adapted to be centered, the periphery of the helix preventing contact between the hole and the vessel wall, and the injection fluid delivered through the hole is diluted by the blood flowing through it immediately before contact with the vessel wall. To be introduced into a vein, the helix is stretched by an introducer needle or wire, and when the introducer needle or wire is withdrawn, the catheter returns to its previous helical shape (shown in the figures).

The connecting element, which is represented in fig. 2a as a schematic top view, has a base plate 9, preferably of longitudinal shape, for attachment to the arm of the patient, and can be slightly concave in order to better adapt to the shape of the body surface. It has an opening 10 for locating and accommodating the mouth. For the preferred embodiment described in fig. 1 (for the case where the intravenous catheter is introduced into a vein, for example at a bend in the arm, with a separate handle between the tip of the catheter and the port for introduction of the catheter), the opening can transition to a slit (not shown) that opens on one side of the base plate to receive and protect the portion of the intravenous catheter that lies on the skin and between the handle and the port.

In the embodiment shown, the means for locating and securing the port is a U-bolt 11, which U-bolt 11 slides in a slot of the connecting member and, after pushing, is securely engaged with a keyway of the port (facilitated by a handle 12 of the bolt). The means for positioning the injection unit shown in the illustrated example is a rim 13 on the upper surface of the coupling unit, which rim 13 has a key way 14 for securing the spring mechanism of the injection unit. The connecting element is attached to the skin by means of an adhesive layer 15.

Fig. 2b shows a cross-sectional view of the connecting element along the axis indicated by the dash-dot line in fig. 2 a. It shows the instrument 16 for positioning the mouth in the opening of the connecting element and shows in a cross-sectional view: a U-bolt 11 having a handle 12, the U-bolt 11 being used to secure the mouth to a side wall 16 of the opening 10; and a rim 13 for positioning the injection unit.

The means for positioning and securing the port and the injection or blood sampling unit relative to each other are also shown in fig. 3 by way of example in a cross-sectional view. The connection unit is attached directly to the skin by means of an adhesive layer 15, and since the port and the injection or blood sampling unit are firmly attached to the connection unit, this adhesive layer forms an adhesive contact surface for the whole device to be temporarily worn on the skin.

Fig. 3 is a schematic cross-sectional view of a device for intravenous delivery of injection fluid into a patient with assembled port, connecting element and injection unit. The figure shows the housing of the port 1 secured to the connecting member by means of a bolt 11, which bolt 11 is firmly engaged in a keyway in a side wall 16 of the opening 10 of the connecting member. The base plate of the connecting element 9 is attached to the skin by means of an adhesive layer 15.

The injection unit has a housing 17, which housing 17 is fixed to the connecting element by means of a hook mechanism 18, which hook mechanism 18 is formed in this embodiment as a spring mechanism engaging with a fixing 14 in the form of a key slot on the connecting element. Such a spring mechanism can be automatically connected upon mounting the injection unit on the connecting element and manually disconnected by pressing the mechanism simultaneously on both sides of the injection unit.

In the shown embodiment the injection unit has a syringe pump, the barrel of which is preferably bent in the shape of a section of a solenoid 19, but other types of pumps (as known in the art) can be used, also mechanical drives (e.g. a clockwork spring drive) moved by an electric motor or other drives known in the art and various combinations of electronic, mechanical, pneumatic and hydraulic components for delivery and control can be used. For a constant delivery of injection fluid, the drive mechanism can be simplified, for example as a spring, as the displacement element.

The injection fluid can be delivered continuously or in desired amounts, for example relative to the concentration of the active substance delivered or the concentration of the analyte of interest (e.g. glucose, for delivering insulin). Thus, a blood sampling unit with a second cannula 20 'can be connected to a micro sensor for e.g. glucose, which second cannula 20' is also connected to a port through a second septum 5 'and a second cavity 5', and the cavity for injection fluid delivery and blood sampling is preferably connected to a dual lumen intravenous catheter, wherein the bore of the injection fluid delivery lumen is downstream in the vein from the bore of the blood sampling lumen. Alternatively, a blood sampling unit having a measurement instrument for one or more analytes or other devices that measure analyte or vital function (e.g., cardiac or brain signals) at other locations remote from the injection fluid delivery device can provide signals for controlled delivery of injection fluid via wireless transmission.

Alternatively, such a syringe pump can also be used for very precise blood withdrawal, and also due to the construction of the syringe pump, which makes the barrel of the syringe pump bent in the shape of a segment of a solenoid for this application, has the great advantage of a compact footprint, very suitable for direct attachment to the skin.

Fig. 4 shows a schematic view of an alternative embodiment of a device for intravenous delivery of injection fluid into a patient, with assembled port, connecting element and injection unit. In such an alternative preferred embodiment, the pump of the injection unit has a flexible reservoir with a rigidly connected cannula and the flexible fluid reservoir is squeezed through a pressurized container connected to a gas generating chamber with an electrical circuit that controls the amount of gas generated by adjusting the current flowing from the gas generating chamber. The flexible reservoir can preferably be manufactured by means of conventional blow-fill-seal technology. Such a pump forms a very compact design and is therefore very suitable for direct attachment to the skin even at high injection fluid volumes of up to 20 ml.

Whereas in the embodiment shown in fig. 3 the fitting between the housing and the connecting element of the injector unit and the simultaneous piercing of the septum of the port by the cannula will be effected by a vertical movement, in the embodiment of the device shown in fig. 4 the fitting and the connection between the housing and the connecting element of the injector unit and the simultaneous piercing of the septum of the port by the cannula will be effected by a horizontal sliding movement.

Figure 4a shows a cross-sectional view of the device with the assembled port, connecting element and injection unit. The housing of the port 1 is fixed to the connecting element by a bolt mechanism (not shown). The base plate of the connecting element 9 is attached to the skin by means of an adhesive layer 15. The housing 17 of the injection unit is fixed to the connecting element by means of a hook mechanism 18, which hook mechanism 18 slides under a fixing 14 in the form of a recess on the connecting element. The base plate of the connecting element 9 may have a tunnel-shaped appendage 22 formed of a flexible and semi-flexible material, acting as a protection for the intravenous catheter when the device cannot be placed directly over the site of venipuncture, for example when the vein at the bend of the arm is used for venipuncture.

Figure 4b shows a horizontal cross-section of the device. In the illustrated embodiment, the injection unit comprises: a pump having a flexible fluid reservoir 23; and an airtight housing 17, the airtight housing 17 acting as a pressurized container, but other embodiments are also possible, such as a separate discharge bag acting as a pressurized container. The pressurized container exerts pressure against the fluid reservoir to cause positive displacement of injection fluid by compressing the collapsible reservoir. The pressurized container is connected to the gas generation chamber 24. The contents of the flexible reservoir 23 are expelled through the cannula 20, through the septum 5 and into the cavity 2 of the port, which cavity 2 is open to the intravenous catheter 3, thereby delivering the injection fluid into the vein of the patient. In the embodiment shown, the control of the amount of gas generated by the gas generating chamber will be adjusted electronically by the control unit 21, preferably by adjusting the current flowing from the gas generating chamber. The flexible fluid reservoir 23 can be made already filled with injection fluid or can be a vacuum-evacuated bag with a membrane 25 so as to be able to be filled by means of a syringe, for example.

The great advantage of the structure according to the invention compared to similar known devices is that the device is attached to the skin and problems with the connection tube between the infusion pump and the intravenous catheter are avoided.

The replacement of connecting tubing with a direct connection between the intravenous catheter and the device, as well as the simplicity of assembly and operation, will result in improved safety, which is important for patient or non-professional healthcare worker acceptance.

In addition, by using a connecting tube in known devices, the dead volume between the pump and the tip of the intravenous catheter obviously requires blood to be drawn to get air out of the system before infusion can begin. Moreover, sampling of the blood for analysis inevitably leads to leakage of blood, which should be avoided for safety reasons, and the dead volume of the connecting tube requires the extraction of an undesirably large amount of blood. The present invention is capable of incorporating all of the safety features of modern intravenous catheter systems while also solving the above problems by a compact device of simple construction, as shown in figures 3 and 4.

Of course, the pumps and their drive means for delivering injection fluid to the patient or for removing blood from the patient or the connection mechanisms between the ports, the connection elements and the injection or blood sampling unit can be realized by a number of alternative possibilities, as is known from the prior art. Moreover, a variety of diagnostic elements for on-line analysis or for sampling the withdrawn blood, as well as control and measurement devices and control functions for delivering the injection fluid can be provided to the device, and those of ordinary skill in the art will appreciate that numerous changes, modifications, and improvements can be made to the specific applications and requirements while remaining within the spirit and scope of the present invention.

Claims (21)

1. An intravenous device for intravenous delivery of an injection fluid into a patient or for removal of blood from a patient, the intravenous device being adhered to skin and comprising:

a port at an outer end of the intravenous catheter, the port having a cavity with at least one septum;

an injection or blood sampling unit;

a connection element having means for positioning and securing the port and the injection or blood sampling unit relative to each other and having an adhesive contacting surface for securing to a patient.

2. The intravenous device of claim 1, wherein: the injection or blood sampling unit is provided with at least one connection cannula which connects the injection or blood sampling unit with the port by piercing the septum of the port.

3. The apparatus according to any one of claims 1 and 2, wherein: the port has a cavity with two or more integrally formed septums, one of which serves as an entry port for introducing a catheter into the vein through a guide needle or wire which can be removed through the septum after introduction, the other septum serving as an entry port for attaching a cannula.

4. The apparatus of any one of claims 1 to 3, wherein: part of the connecting element is fused to the port or to the injection or blood sampling unit.

5. The apparatus of any one of claims 1 to 4, wherein: the connecting element is provided with elastic means by which the connection and positioning of the port and the injection or sampling unit is automatically effected when pressed against each other, while the septum is pierced by the connecting cannula.

6. The apparatus of any one of claims 1 to 5, wherein: the connection element comprises driving means for the connection element, which regulating the movement of the port and the injection or blood sampling unit relative to each other.

7. The apparatus of any one of claims 1 to 6, wherein: an infusion or blood sampling unit comprises a pump for delivering or withdrawing fluid, which pump is regulated by an integrated control device or remote control.

8. The apparatus of any one of claims 1 to 7, wherein: pumps for delivering or drawing fluids include syringe pumps.

9. The apparatus of claim 8, wherein: the barrel of the syringe pump is bent into the shape of a segment of a solenoid, wherein its axis forms a segment of a circle.

10. The apparatus of any one of claims 1 to 9, wherein: both the injection and blood sampling units are coupled to the port and are simultaneously connected to the port by a double lumen intravenous catheter having a separate septum for connection.

11. The apparatus of any one of claims 1 to 10, wherein: the blood sampling unit further comprises measuring means for one or more analytes, the results of which measurements can be displayed, wirelessly transmitted and/or used for controlled delivery of injection fluid.

12. The apparatus of any one of claims 1 to 11, wherein: the blood sampling unit further comprises means for collecting a plurality of blood samples, avoiding mixing over a period of time.

13. The apparatus of any one of claims 1 to 12, wherein: the blood sampling unit further comprises means for controlled introduction of multiple segments of air or immiscible fluids to avoid mixing over time.

14. The apparatus of any one of claims 1 to 13, wherein: pumps for delivering fluid have a flexible reservoir, a drive mechanism that causes a positive displacement of the injected fluid by compressing the reservoir, and a control mechanism for regulating the flow rate.

15. The apparatus of claim 14, wherein: the drive mechanism for causing positive displacement of the injected fluid by compressing the reservoir is pressurized gas generated by the gas-generating chamber and the control mechanism for regulating the flow is an electrical circuit that regulates the current flowing from the gas-generating chamber.

16. The apparatus of any one of claims 1 to 15, wherein: the components of the injection or blood sampling unit consist of a reusable component and a disposable component.

17. The apparatus of any one of claims 1 to 16, wherein: the intravenous end of the intravenous catheter, which is stretched by means of a guide needle or wire for introduction into the vein, is preformed in the shape of a spiral with a hole adjusted to be centered to avoid direct contact of the hole with the inner wall of the vein.

18. A method for securing a mobile intravenous access port through an intravenous catheter connected to an injection or blood sampling unit by a skin-adherent connecting element, by:

(a) providing an intravenous catheter arrangement with a port having a septum;

(b) positioning and securing an attachment element having an adhesive surface for attachment to the skin over the port as a connection to an injection or blood sampling unit;

(c) attaching an injection or blood sampling unit having a connection cannula to the connection element, the connection cannula piercing the septum of the port;

(d) the mechanism for initiating the injection and/or blood sampling process is actuated.

(e) The method of claim 17, for performing a bolus injection of a drug over an extended period of time.

19. The method of claim 18, for performing a bolus injection of a drug over an extended period of time.

20. The method of claim 18, for moving the concentration-time profile of an analyte in blood over an extended period of time.

21. The method of claim 20, wherein the metabolic and drug metabolic states of the subject are given mobilely by: administering one or more substances or drugs to the individual; and measuring the resulting concentration-time profile, including the metabolite.