HK1228320A1 - Pump arrangement - Google Patents

Abstract

The subject matter of the present invention is a pump arrangement (1, 10, 20, 30, 40, 50), in particular for use in the body's own vessels, having a pump (11, 41, 51) and a sheath (12, 42, 52) receiving the pump, bounding a flow passage (S) and having a distal intake opening (13, 43, 53) and a proximal outflow opening (14, 29, 39, 44, 54) for producing a driving flow by means of the pump, wherein the pump is arranged in a first fluid-tight section (12a, 42a, 52a) having the distal intake opening and a second fluid-tight section (12b, 42b, 52b) includes the proximal outflow opening. In accordance with the invention, a further inlet opening (15) is present between the first section and the second section and is arranged between the intake opening und the outflow opening, with the first section and the second section being arranged with respect to one another such that the inlet opening opens into the flow proximal to the pump.

Description

Pump device

Technical Field

The invention relates to mechanical engineering and precision machines, which can be used advantageously in particular in the medical field.

Background

In this respect, the subject of the invention is a pump device according to the preamble of claim 1.

In the prior art, pump devices are increasingly known, in particular for use in human blood vessels. The pump may be used, for example, for short-term cardiac support to relieve the heart muscle after a patient experiences cardiogenic shock (acute myocardial infarction). In this procedure, it is sometimes used as a microaxial pump implanted through the femoral artery.

Such a pump device is known, for example, from EP2047872a 1. The pump device disclosed therein comprises a pump, a sheath accommodating the pump and having a distal intake opening and a proximal outflow opening, the pump generating in operation a drive flow from the distal intake opening to the proximal outflow opening. This extends a flow path between the inlet and outlet ports. In this regard, the pump may be disposed within a first fluid tight portion of the sheath that constitutes the PU coating of the housing and has a distal intake port. Further, a second fluid tight portion of the sheath is provided, the second fluid tight portion comprising a proximal outflow port and being in the form of an outflow hose. The outflow hose is connected to the PU coating, which connection has material continuity. The pump means is arranged as a pump in the form of a rotor, which may for example be placed in the ventricle, with the outflow hose extending from the ventricle to the aorta.

All blood entering the aorta via the outflow opening of the outflow hose enters the flow channel formed by the sheath via the suction opening and thus flows through the rotor. That is, the pump delivers fluid equivalent to the fluid exiting the outlet port.

The subject matter of documents DE4124299a1, DE102004054714a1, WO2007/112033a2 and US2008/132748a1 also works according to the above-mentioned principle.

Since all blood is in direct contact with the pump, this requires a particularly great effort in the manufacture of the pump to reduce the damaging effect of the moving parts of the pump on the blood. This blood damaging effect is demonstrated in direct mechanical shearing of moving and stationary pump components and in shearing by shear stress fields present as the fluid passes through the flow channel (as described above). The pump geometry is thereby increased and cannot be used in minimally invasive surgery.

Disclosure of Invention

The underlying object of the invention is to reduce the risk of blood or fluid damage through the pump. Of particular note is the choice of materials for the following pump devices when used in the medical field. The material should reasonably meet the requirements of biocompatibility. In addition to the above-described implementations, interaction with foreign body surfaces is the third largest aspect of blood damage and has been well studied for some time.

According to the invention, an additional inflow opening is introduced between the first part and the second part, said first part and said second part being arranged opposite each other such that the inflow opening communicates with the flow channel at the proximal end of the compressible pump. In this connection, the additional inflow opening can also be formed as an inflow channel, the inflow opening of which communicates with the flow channel at the distal or proximal end of the pump or at the same level as the pump, but only at the proximal end of the compressible pump.

By virtue of the features of the invention, the driving flow through the pump flows through the flow channel and through the opening of the inflow opening towards the outflow opening, thus creating a pressure drop relative to the fluid pressure inside the inflow opening, causing fluid to be sucked from the inflow opening into the flow channel. Thus, the total flow out of the outflow is greater than the drive flow that flows directly through the pump and is thus delivered, since an additional suction flow is added at the inflow.

The suction flow is generated due to the suction effect created by the drive flow, which also occurs in some types of turbines or water jet pumps. In the suction effect, the impulse is transmitted from the driving flow to the suction flow by friction or viscous or turbulent mixing of the fluid. In this way, viscous, turbulent shear stresses are generated. The direction of propulsion of the power flow is transmitted to the particles of the medium of the suction flow to be conveyed, which are conveyed to the downstream region within the jacket.

In essence, by means of the features of the invention, the ejector pump principle is achieved in that the drive flow is passed directly through the pump and is conveyed together with the suction flow flowing in from the additional inflow opening.

In this respect, the inflow port is located between the first and second portions and has an inlet, which may be at the proximal or distal end of the pump, which is more advantageous if the inlet is located at the distal end of the outflow port. The opening of the inflow opening into the flow channel should only be at the proximal end of the pump in order to make good use of the suction effect created by the driving flow.

It will be appreciated that the compression pump is preferably a radially compressible pump or pump arrangement. In this regard, the inner diameter of the conduit is smaller than the first and second portions or housings when the pump is in the deployed state, the pump or the first and/or second portions and/or housings and/or rotors being configured such that the pump can be directed to a target location within the conduit. Such pumps or pump arrangements are known, for example, from documents EP2047872a1, WO2010/063494a1, US61/120,095 or WO2010/127871 and US61/175,519a 1.

It is particularly advantageous to form an inflow opening between the suction opening and the outflow opening.

The first and second portions of the sheath may be integrally formed or may be provided as separate components.

In one embodiment, the cross-section of the proximal end of the first portion is smaller than the cross-section of the distal end of the second portion. The transport stream thus converges in the cross-sectional area proximal to the first portion and may carry additional media into the second portion, which media may flow in at least through the remaining area of the cross-section distal to the second portion.

In another embodiment, the cross-section of the first portion converges towards its proximal end. Due to this bunching, the first portion assumes a nozzle shape at its proximal end. This results in an increase in efficiency and thus an increase in the suction flow of the suction. In addition, this feature helps achieve the effect of reducing the overall pump device.

In another embodiment, the distal end of the second portion overlaps the proximal end of the first portion, e.g., the distal end of the second portion is closer to the distal end than the proximal end of the first portion. In this connection, it is advantageous if the inflow opening between the first part and the second part forms in each case a suction flow channel or a passage from the distal end of the second part to the proximal end of the first part. Preferably, the suction flow is here approximately coaxial to the conveying direction of the drive flow, enters the flow channel through the suction flow channel and flows to the outflow opening. In this respect, since the main axis of the suction flow channel is preferably directed towards the fluid to be delivered, the driving flow impulse directed towards the outflow opening has been transmitted to the suction flow. This results in an increase in efficiency.

In another embodiment, the distal end of the second portion is closer to the proximal end than the proximal end of the first portion or at the same level as the proximal end of the first portion. Due to the spacing, the converging drive stream, upon exiting the proximal end of the first portion, encounters fluid of different pressure and direction, such that the converging transport stream, like the more dense fluid, flows into the beginning of the second portion defined by the distal end of the second portion and carries fluid between the first and second portions. Thus, more total flow is provided than drive flow through the pump. In this respect, however, it must be noted that the spacing between the distal end of the second portion and the proximal end of the first portion is kept small so as not to create any dispersion of the transport flow with respect to the fluid outside the sheath. The spacing should be between about 0 and 1/4 of the diameter of the proximal outflow opening of the first portion.

In another embodiment, the second part comprises at least one partial region made of a flexible material. Thus, taking the example of the second part being placed between a heart chamber and a blood vessel, the central chamber and the blood vessel being connected by a rhythmically opening valve, the second part can be pressed into the valve and fluid can thus be delivered sequentially under rhythmic valve motion. For example, PU, PE, PP, silicone or parylene may be suitable materials, provided that they meet mechanical and geometrical requirements, as well as biocompatibility requirements.

In another embodiment, the pump device has a housing therein that houses the pump. This is particularly suitable when the pump is a compressible pump, which can be transported by means of a conduit to its place of operation together with the housing. The housing may be made of, for example, nickel titanium alloy (Nitinol).

When a housing is present, the first part can be made as a shell or coating of the housing, only a partial region of the housing, preferably an axial partial region, having to be provided with a fluid-tight shell or coating. Materials suitable for forming the coating or envelope have been indicated in the description of the second part being formed of a flexible material.

In another embodiment, the housing has a constriction and/or bulge at the proximal end of the pump. In this context, narrowing is understood to mean the convergence of the housing cross section with respect to the region of the housing accommodating the pump. Bulging is the enlargement of the cross section of the housing relative to a narrowing or relative to the area of the housing accommodating the pump. A larger cross-section of the converging portion or of the second portion of the first portion can be achieved in a particularly simple and advantageous manner by means of such a shape. The second portion may also be connected to the housing.

In another embodiment, the first portion and the second portion are connected to each other, the connection having material continuity; or preferably both.

In another embodiment, the second portion is formed as an outflow hose.

In another embodiment the first part, the second part or any housing comprises a support element, such as a support ring, a plastic wire, a metal wire, a connecting strut or preferably a compressible sleeve, for spacing the first part from the second part. In this way, the surface of the second portion is not attracted to the surface of the first portion by the suction flow flowing through the inlet, interrupting the suction flow, or, in this way, ensuring that the additional inlet is always open during operation of the pump. In this respect, the support elements are connected to the first or second part so that they can be compressed together with the pump. This may be achieved by an elastic support element or a support element made of a superelastic material or a memory material such as nitinol.

The second portion may further have a support ring in the flow inlet region, the support ring ensuring that the first portion and the second portion are spaced apart in the flow inlet region such that a surface of the second portion does not adhere to a surface of the first portion to disrupt the suction flow as the suction flow flows through the flow inlet. It is particularly advantageous when the second part is made of a flexible material, such as an outflow hose.

In another embodiment, the second part has a sleeve comprising an additional inflow device or the part comprises an additional inflow opening. The sleeve may be connected as an additional form part, for example, to the flexible region of the second part. In this connection it is advantageous if the sleeve is of stable shape and thus forms a suitable damping with respect to the fluid in the operating state, so that the suction flow is guided by the sleeve and flows into the flow channel. The operating state is defined, for example, by the deployment of the pump device at a work site in the body.

Instead of a sleeve, an additional hose section or tube may also be used.

In another embodiment, the pump is a compressible pump, thereby making it easier to introduce the pump into the blood stream or vessel.

It is further advantageous if the pump is an axial flow pump fastened to a rotatable shaft which can drive the pump.

Drawings

The present invention will be described in further detail below with reference to some examples. Wherein:

FIG. 1 is an application of a pump device in a heart;

FIG. 2 is a schematic view of a pump device in one embodiment;

FIG. 3 is a schematic view of an inflow port of a pump device in one embodiment;

FIG. 4 is a pump assembly in one embodiment;

FIG. 5a is a pump device in another embodiment;

FIG. 5b is a schematic view of the pump apparatus of FIG. 5 a;

FIG. 6 is a pump device in yet another embodiment;

FIG. 7 is a pump apparatus according to yet another embodiment; and

fig. 8a-8c are cross-sections of different pump devices.

List of reference numerals

1, 10, 20, 30, 40, 50 pump device

2 blood vessels

3 ventricle

4 vessel wall

5 cardiac valve

6 blood vessel valve

11, 41, 51 pump

12, 42, 52 sheath

12a, 42a, 52a first part of a sheath

12b, 42b, 52b sheath

13, 43, 53 suction inlet

14, 44, 54 outflow opening

15 flow inlet

16 proximal to the first part

17 pressure drop zone

21, 31 rotor

22, 32 axes

23, 33 outer casing

24, 34 envelope

Length of L24, L34 cladding

25, 35, 420b outflow hose

26, 36 suction flow passage

27 inlet

28 support Ring/spacer (spacer)

33a narrowing

33b bulge

421b sleeve

422b spacer

Q_TTransport stream

Q_sInhalation flow

Q_ATotal flow

A₁，A₂，A_1D，A_1P，A_2DCross section of

Detailed Description

Fig. 1 shows a possible application of a pump device 1. The pump device 1 comprises an elongated catheter extending within the blood vessel 2 and a shaft extending within the catheter for driving a pump in the pump device 1, which pump forms a rotor. The proximal end of the pump device (without catheter when viewed) is located in the blood vessel 2, while the distal end of the pump device 1 including the pump is located in the ventricle 3. The vessel 2 is defined by a vessel wall 4. The rhythmically open and closed valve 5 further defines the ventricle 3 and allows blood to flow from the ventricle 3 into the blood vessel 2.

In addition to the application of the pump device according to the above information, the pump device has further applications. The pump may be used, for example, in different blood vessels in the body to improve delivery performance.

The mode of operation of the pump device of the present invention is explained with reference to fig. 2. The pump device 10 comprises a pump 11 in the form of a rotor. The pump 11 is driven in rotation by a shaft, not numbered, shown, and can thus convey a driving flow Q_T. The pump device 10 has a sheath 12, the sheath 12 comprising a first portion 12a and a second portion 12 b. The suction opening 13 is located in the first section 12a, through which fluid can enter the lumen of the first section 12a, be sucked in by the pump 11 and act as a driving flow Q_TTowards the outflow opening 14. The jacket 11 defines a flow path S between the intake opening 13 and the outflow opening 14, said flow path comprising the entire lumen of the first portion 12a and comprising part of the lumen of the second portion 12 b.

The first and second portions overlap between the proximal end of the first portion 12a and the distal end of the second portion 12 b. An inflow opening 15 is defined by this overlap, through which inflow opening 15 fluid can enter the flow channel S from a region outside the lumen of the first section 12 a. Due to the pump delivering a driving flow Q_TA pressure drop occurs in the region 17 of the proximal end 16 of the first section. This is shown in fig. 3.

Due to the pressure drop in the area 17, more fluid is sucked in through the inflow opening 15 in a direction towards the outflow opening 14 and as a suction flow Q at a location close to the proximal end 16 of the first section_sAnd enters the flow channel.

Both the first portion 12a and the second portion 12b include an internal cavity. In this regard, the lumen of the first portion 12a has a cross-sectional area A₁(ii) a The lumen of the second portion 12b has a cross-sectional area A₂. In this embodimentMiddle, cross section A₁And A₂Each remaining constant over the total length of the first and second portions; however, this is not a necessary feature. Since the flow channel extends parallel to the driving flow between the distal end of the second section 12b and the proximal end of the first section 12a and forms the inflow opening 15, the suction flow has been subjected to a pushing force in the direction towards the outflow opening 14. Volume per unit time Q of the fluid flowing out of the outflow opening 14_AGreater than the driving flow Q through the pump_TDue to the additional suction flow Q_s。

Fig. 4 depicts a pump device in another embodiment. The pump device 20 is located in a blood vessel, which is defined by a vessel wall 4. The distal end of the pump device 20 is located distal to the valve 5; the proximal end is located at the proximal end of the valve 5.

The pump device 20 comprises a compressible rotor 21, which rotor 21 is fastened on one side to a shaft 22. A bearing is located at the proximal end of the rotor. The rotor 21 is surrounded by a housing 23, which housing 23 may be made of nitinol. The housing includes individual wires, wires or struts of nitinol that may be interdigitated to create a diamond pattern. Fluid may flow through the diamond and reach the rotor 21.

The housing 23 is partially covered by an envelope 24 in a fluid-tight manner. In this regard, the envelope 24 extends a length L₂₄So that the rotor-driven drive flow QT converges and leaves the housing 23 at the proximal end of the envelope 24 in the direction of an outflow opening 29, which is provided in the outflow hose 25.

In this embodiment, the enclosure 24 of the pump device 20 forms a first part of the sheath; the outflow hose 25 forms a second part of the sheath. The distal end of the outflow hose is fastened to the housing 23 and is closer to the distal end than the proximal end of the sheath 24.

The sheath 34 is gathered in the proximal direction in the region of the rotor 21. The cross-sectional area A of the cavity formed by the sheath 24 in the region of the rotor 21 is thus_1DGreater than the cross-sectional area A of the proximal end of the sheath 24_1P. Thus producing a nozzle effect which accelerates the driving flow Q according to the venturi principle_TTo cause it to flow upstream at a faster rate proximally of the sheath 24The direction of the outlet 29. The suction channel 26 between the jacket 24 and the outflow hose 25 is open via an inlet 27. As can be seen from fig. 4, a plurality of inlets 27 are provided, which are designed with a circular cross-section at the distal region of the outflow hose. Due to the leaving drive flow Q_TPressure drop, suction flow Q_sIs sucked in through the inlet 27 and the suction channel 26 and flows into the channel S, which delivers all the flow to be delivered to the outflow 29.

In the operating state of the pump, a form-stable support ring 28 is located proximal to the inlet 27 and radially on the periphery of the outflow hose 25. In this way, the surface of the outflow hose 25 caused by the generated suction flow is prevented from catching the sheath 24. Thus, the suction flow channel 26 remains open and drives the flow Q_TMore fluid is drawn into the flow path S through the suction flow path 26.

A pump device according to yet another embodiment of the invention is shown in fig. 5 a. The pump device 30 comprises a rotor 31, both sides, i.e. the distal and the proximal end, of said rotor 31 being supported on a shaft 32. Rotor 31 is placed in housing 33 and housing 33 is partially encased by PU coating 34. In this regard, the length L of the PU coating 34₃₄To a region adjacent the proximal end of the rotor 31. The housing 33 has a constriction 33a and expands at the proximal end of the constriction 33a to form a bulge 33 b. In the region of the bulge 33b, an outflow hose 35 is connected to the housing 33, and the connection has material continuity. The bulge 33b and the constriction 33a are spaced from each other by a spacing d in the direction of the axis 32 of about 0-1/4 of the diameter of the constriction 33 a. In this respect, due to the driving flow Q_TLeaving the proximal end of the PU coating 34 and driven by the rotor 31, the spacing d is chosen such that the flow Q is inhaled_sTo be sucked in from the inflow port 36 formed between the PU coating 34 and the outflow hose 35. Drive flow Q out of wrapper 34_TAt a pressure P₁And (4) flowing out. Pressure P applied externally of envelope 34₂Less than pressure P₁. Suction flow Q_sIs sucked into the inflow opening 36 as a result of this pressure difference and is conveyed via the outflow hose to the outflow opening 39, where it is provided as a total flow Q_AAt a pressure P₃Is discharged at a pressure P₃Greater than pressure P₂. In this respect, the total flow Q_ALess than drive flow Q_T。

Even if the flow path S extending between the suction port and the discharge port 39 at the distal end of the rotor 31 is permeable to the fluid between the proximal end of the PU coating 34 and the distal end of the discharge hose 35, the inflow port 36 communicates with the flow path according to the flow process of the driving flow. If the flow rate of the driving flow is relatively high, it will in fact enter the outflow hose directly.

Since an inflow port other than the suction port is provided at the distal end of the rotor 31, the total flow Q from the outflow port 39_ADoes not pass the rotor 31 and so there is no risk of blood damage by the rotor 31.

Fig. 5b again shows the pump device 30 in the embodiment of fig. 5 a. It can be seen that the cross-sectional area A is at the distal end of the PU coating 34_1DThe area ratio is the cross-sectional area A located proximal to the PU coating 34_1PIs large. The inner cavity surrounded by the PU coating 34 is gathered, and the effect of improving the efficiency is achieved. Cross-sectional area a of the lumen of the outflow hose 35_2DIs correspondingly larger than the cross-sectional area A_1P. Thus, the inflow opening 36 is defined by at least the cross-sectional area A_2DMinus the cross-sectional area A_1PThe area left behind. The inflow openings are correspondingly in communication with the flow channel S.

Figure 6 shows a pump arrangement in a further embodiment. In this regard, a detailed description of the shaft and pump drive is omitted. The pump device 40 comprises a rotor 41 and at the same time a first part 42a and a second part 42b of the sheath. A suction port 43 for supplying fluid to the pump 41 is located at the distal end of the first portion 42 a. The fluid supplied to the pump 41 is accelerated and acts as a drive flow Q_TAnd is expelled at the proximal end of the first portion 42 a. The second part 42b consists of an elastic region 420b, which elastic region 420b is connected to a compressible sleeve 421b having a stable shape and being stiff in the operating state. Compressible sleeve 421b is connected to first portion 42a by a plastic wire or wire 422 b. The cross-section of which extends in a converging manner from the distal end of the cannula 421b to the proximal end of the cannula 421b, with the driving flow Q_TCooperate to draw in the suction flow Q from the inlet 45_sThe inflow port 45 is formed between the sleeve 421b and the first portion 42a, and the flow Q is sucked_sIn the flow path S with the drive flow Q_TAre combined and taken as the total flow Q_AAnd flows out from the outflow port 44. Accordingly, as is apparent from fig. 6, the inflow port 45 communicates with the flow path S.

Fig. 7 shows a pump device in a further embodiment. The pump arrangement 50 comprises a pump 51 which is an axial flow pump with a rotor. Further, a sheath 52 is provided which is separable into a first portion 52a and a second portion 52 b. In this regard, the first and second portions may be connected to one another, the connection may be material continuity, or both may be integrally formed. A suction port 53 for supplying fluid to the rotor is located at the distal end of the sheath 52 to drive the flow Q_TIs transported in the operating state of the rotor. Drive stream Q_TIs conveyed toward the outflow port 54. The inlet 55 is located between the first portion 52a and the second portion 52b, and sucks the flow Q_sDriven flow Q_TThe flow passage S defined by the sheath 52 can be accessed via the inflow opening 55. A particular feature of this embodiment is that in contrast to the previously illustrated embodiment, the first portion is a separate component from the second portion, whereas the sheath 52 of this embodiment is integrally formed.

Some different geometries of the flow inlet are shown in fig. 8a-8 c.

One cross-section in the corresponding embodiment of fig. 6 is shown in fig. 8 a. It can be seen that the suction inlet 543 has a cross-sectional area a_1P. Adjacent the proximal end of the inhalation port, i.e., further into plan view, sleeve 421b has a cross-sectional area A measured at its outermost periphery_2D. A plastic wire 422b connects the sleeve 421b to the first portion 42 a.

The cross-section in the corresponding embodiment of fig. 5a is shown in fig. 8 b. It can be seen that the intake opening 33 is defined by the PU coating 34. PU jacket 34 also defines a cross-sectional area A in the rotor region_1DThe lumen of (a). In addition, it can be seen that the shaft 32 is located at the center of the suction port 33. The proximal end of the rotor (compare fig. 5a), made of wire, nitinol wire or strutThe outer shell 33 converges to a cross-sectional area A defined by a constriction 33a_1P. At the proximal end, the housing 33 widens to form a bulge 33b, to which the outflow hose 35 is connected in the bulge region. As can be clearly seen, with reference to the illustration in fig. 8b, a region 36 as an inflow for the suction flow is located between the outflow 35 and the PU coating 34.

The cross-section in the corresponding embodiment of fig. 4 is shown in fig. 8 c. In this respect, a cross-section of the level (level) at which the support ring 28 is located is shown. It can be seen that is defined by the first portion of the envelope 24 and has a cross-sectional area A_1DThe lumen of (a). The drive flow passes through the lumen of the sheath 24 in a proximal direction, driving additional fluid to be drawn in through the intake flow path 26, the intake flow path 26 being located between the sheath 24 and the outflow hose 25. The outflow hose 25 has a cross-sectional area a in this region_2D. The support ring 28 is clearly visible and it can also be seen that connecting struts 28a connect the support ring to the envelope 24. The support ring is made up of a number of segments 28b which can be brought into a folded state for introduction of the pump device by means of a duct.

Claims (15)

1. A pump device (1, 10, 20, 30, 40, 50), in particular for body vessels, having a compressible pump (11, 41, 51) and a sheath (12, 42, 52) for accommodating the pump, which sheath defines a flow channel (S) and has a distal intake opening (13, 43, 53) and a proximal outflow opening (14, 29, 39, 44, 54) for generating a drive flow (Q) by the pump_T) Wherein the pump is interposed between a first fluid tight section (12a, 42a, 52a) having the distal intake port and a second fluid tight section (12b, 42b, 52b) including the proximal outflow port, characterized in that:

between the first and second parts, an additional inflow (15) is provided, the first and second parts being arranged opposite each other such that the inflow communicates with the flow channel (S) at the proximal end of the pump.

2. Pump device according to claim 1, characterized in that the cross section (A) of the proximal end of the first portion_1P) Smaller than the cross-section (A) of the distal end of the second portion_2P)。

3. Pump device according to any one of the preceding claims, characterized in that the cross section (A) of the first portion_1D，A_1P) Converging towards its proximal end.

4. A pump device according to any one of the preceding claims, wherein the distal end of the second part is arranged closer to the distal end than the proximal end of the first part, and the inflow opening forms an intake channel (26, 36) extending between the first and second parts.

5. A pump arrangement according to any one of the preceding claims, wherein the distal end of the second part is arranged closer to the proximal end than the proximal end of the first part or at the same level as the proximal end of the first part.

6. Pump device according to any one of the preceding claims, characterized in that the second portion (12b, 42b, 52b) comprises a region made of a flexible material.

7. Pump arrangement according to any one of the preceding claims, characterized by a housing (23, 33) for accommodating the pump.

8. Pump apparatus according to claim 7, characterized in that the first part is an envelope (24, 34) of the housing (23, 33).

9. Pump device according to claim 7 or 8, characterized in that the second part is connected with the housing (23, 33).

10. A pump arrangement according to any one of the preceding claims, wherein the first and second parts are interconnected and have material continuity.

11. Pump arrangement according to any of the preceding claims, characterized in that the second part comprises an outflow hose (25, 35, 420 b).

12. A pump arrangement according to any one of the preceding claims, wherein the first or second part has a support element for spacing the first and second parts apart.

13. Pump arrangement according to claim 12, characterized in that the second part has a support ring (28) in the flow inlet region.

14. Pump device according to any of the preceding claims, characterized in that the second part comprises a sleeve (421b) containing an additional inflow (15).

15. Pump arrangement according to any of the preceding claims, characterized in that the pump (11) is arranged on a rotating shaft (16, 22, 32).