Pump arrangement

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 and 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.

Claims

1. A blood pump assembly comprising: an elongate catheter having a proximal end and a distal end; a compressible rotor disposed at a distal end of the elongate catheter; a housing surrounding the compressible rotor, the housing including a proximal end and a distal end, the housing shaped to define a flow-path and comprising: a first fluid-tight section disposed at the distal end of the housing, the first fluid-tight section comprising a distal end defining a distal opening, a proximal end defining a proximal opening, and a central bore extending from the distal opening to the proximal opening, the central bore being radially fluid tight between the distal opening and the proximal opening; a second fluid-tight section at least partially comprised of an elastic material and disposed at the proximal end of the housing, the second fluid-tight section comprising a flared distal end, a first blood inlet disposed at a distal end of the second fluid-tight section, and a blood outlet disposed at a proximal end of the second fluid-tight section, wherein the flared distal end defines the first blood inlet, and wherein the second fluid-tight section is radially fluid-tight between the first blood inlet and the blood outlet; wherein the second fluid-tight section and the first fluid-tight section are coaxial, wherein a cross-sectional area of a proximal end of the first fluid-tight section is smaller than a cross-sectional area of a distal end of the second fluid-tight section, and wherein the proximal end of the first fluid-tight section is distal to a proximal end of the second fluid-tight section.

2. The blood pump assembly of claim 1, wherein the portion of the second fluid-tight section comprised of a flexible material is elastically compressible.

3. The blood pump assembly of claim 2, wherein first fluid-tight section is coupled to the second fluid-tight section by one or more wires.

4. The blood pump assembly of claim 3, wherein the housing comprises nitinol struts.

5. The blood pump assembly of claim 4, wherein the distal opening of the second fluid-tight section defines a second blood inlet.

6. The blood pump assembly of claim 5, wherein the second blood inlet has a circular cross-section.

7. The blood pump assembly of claim 6, wherein the first blood inlet and the second blood inlet are coaxial.

8. The blood pump assembly of claim 7, wherein the cross-sectional area of the central bore of the first fluid-tight section is substantially constant.

9. The blood pump assembly of claim 8, wherein the first fluid-tight section further comprises a bulge.

10. The blood pump assembly of claim 9, wherein the bulge is disposed distal to a constriction of the first fluid-tight section.

11. The blood pump assembly of claim 10, wherein the elongate catheter is sized for percutaneous insertion into a blood vessel of a patient.

12. The blood pump assembly of claim 11, wherein the rotor is disposed within the first fluid-tight section.

13. The blood pump assembly of claim 1, wherein the flared distal end of the second fluid-tight section at least partially encloses the first fluid-tight section.

14. A blood pump assembly comprising: an elongate catheter having a proximal end and a distal end; a compressible rotor disposed at a distal end of the elongate catheter; a housing surrounding the compressible rotor, the housing including a proximal end and a distal end, the housing shaped to define a flow-path and comprising: a first fluid-tight section disposed at the distal end of the housing, the first fluid-tight section comprising a distal end defining a distal opening, a proximal end defining a proximal opening, and a central bore extending from the distal opening to the proximal opening, the central bore being radially fluid tight between the distal opening and the proximal opening, wherein the central bore has a circular cross section; a second fluid-tight section at least partially comprised of an elastic material and disposed at the proximal end of the housing, the second fluid-tight section comprising a flared distal end, a first blood inlet disposed at a distal end of the second fluid-tight section, and a blood outlet disposed at the proximal end of the second fluid-tight section, wherein the flared distal end defines the first blood inlet, wherein the second fluid-tight section is radially fluid tight between the first blood inlet and the blood outlet; wherein the second fluid-tight section and the first fluid-tight section are coaxial, wherein a cross-sectional area of a proximal end of the first fluid-tight section is smaller than a cross-sectional area of a distal end of the second fluid-tight section, wherein the proximal end of the first fluid-tight section is distal to a proximal end of the second fluid-tight section, and wherein the second fluid-tight section is coupled to the first fluid-tight section by one or more wires.

15. The blood pump assembly of claim 14, wherein the first fluid-tight section further comprises a bulge.

16. The blood pump assembly of claim 15, wherein the bulge is disposed distal to a constriction of the first fluid-tight section.

17. The blood pump assembly of claim 16, wherein the housing comprises nitinol struts which form a diamond pattern.

18. The blood pump assembly of claim 17, wherein the elongate catheter is sized for percutaneous insertion into a blood vessel of a patient.

19. The blood pump assembly of claim 18, wherein the rotor is disposed within the first fluid-tight section.

20. The blood pump assembly of claim 14, wherein the flared distal end of the second fluid-tight section at least partially encloses the first fluid-tight section.

Description

(1) The invention will be described in the following in more detail with reference to some embodiments. There are shown:

(2) FIG. 1 the use of a pump arrangement in a heart;

(3) FIG. 2 a schematic representation of an embodiment of the pump arrangement;

(4) FIG. 3 a schematic representation of an inlet opening of an embodiment of the pump arrangement;

(5) FIG. 4 an embodiment of a pump arrangement;

(6) FIG. 5a a further embodiment of a pump arrangement;

(7) FIG. 5b a schematic representation of the pump arrangement of FIG. 5a;

(8) FIG. 6 a further embodiment of a pump arrangement;

(9) FIG. 7 a further embodiment of a pump arrangement; and

(10) FIGS. 8a-8c cross-sections through different pump arrangements.

(11) A possible use for the pump arrangement 1 is shown in FIG. 1. The pump arrangement 1 includes an elongate catheter which extends through the blood vessel 2 and in which a shaft extends which drives the pump present in the pump arrangement 1 and formed as a rotor. The proximal end of the pump arrangement (viewed without the catheter) is located in the blood vessel 2, whereas the distal end of the pump arrangement 1 including the pump is located in the ventricle 3. The blood vessel 2 is bounded by the vessel wall 4. The valve 5 which opens and closes rhythmically furthermore bounds the ventricle 3 and enables the blood flow from the ventricle 3 into the blood vessel 2.

(12) Further uses are possible in addition to the shown use of a pump arrangement in accordance with the information. The pump can thus, for example, be used in a different vessel of the body to increase the conveying performance.

(13) The mode of operation of a pump arrangement in accordance with the invention should be explained with reference to FIG. 2. The pump arrangement 10 includes a pump 11 which is formed as a rotor. The pump 11 is set into rotation by means of a shaft which is shown, but not numbered and can thus transport a driving flow Q.sub.T. The pump arrangement 10 has a sheath 12 which includes a first section 12a and a second section 12b. An intake opening 13 is located in the first section 12a through which intake opening a fluid can enter into the lumen of the first section 12a, is sucked in by the pump 11 and is transported as a driving flow Q.sub.T in the direction of the outflow opening 14. The sheath 11 defines the flow passage S between the intake opening 13 and the outflow opening 14, said flow passage completely including the lumen of the first section 12a and partially including a lumen of the second section 12b.

(14) The first section and the second section overlap between the proximal end of the first section 12a and the distal end of the second section 12b. An inlet opening 15 is defined by the overlap through which the fluid can enter into the flow passage S from a region outside the lumen of the first section 12a. A pressure drop occurs in the region 17 in the region of the proximal end of the first section 16 due to the driving flow Q.sub.T conveyed by the pump. This is shown in FIG. 3.

(15) Further fluid is sucked through the inlet opening 15 in the direction of the outflow opening 14 due to the pressure drop in the region 17 and enters into the flow passage as the intake flow Q.sub.s proximal to the proximal end of the first section 16.

(16) The first section 12a and the second section 12b both include a lumen. In this respect, the lumen of the first section 12a has a cross-sectional area A.sub.1; the lumen of the second section 12b has a cross-sectional area A.sub.2. In the present embodiment, the cross-sections A.sub.1 and A.sub.2 remain the same over the total length of the respective section; however, this is not a compulsory feature. The intake flow already receives an impulse direction in the direction of the outflow opening 14 due to the passage extending parallel to the driving flow between the distal end of the second section 12b and the proximal end of the first section 12a and formed as an inlet opening 15. The volume per time Q.sub.A which has flowed out at the outflow opening 14 is larger due to the additional intake flow Q.sub.S than the driving flow Q.sub.T passing through the pump.

(17) A further embodiment of a pump arrangement is described in FIG. 4. The pump arrangement 20 is located in a blood vessel which is bounded by the vessel walls 4. The distal end of the pump arrangement 20 is located distal of the valve 5; the proximal end is located proximal to the valve 5.

(18) The pump arrangement 20 includes a compressible rotor 21 which is fastened to the shaft 22 at one side. The bearing is located at the proximal end of the rotor. The rotor 21 is surrounded by a housing 23 which can be manufactured from Nitinol. The housing comprises individual threads, wires or struts of Nitinol which mutually cross and produce a diamond pattern. The fluid can pass through the diamonds and so reach the rotor 21.

(19) The housing 23 is partly covered by a jacketing 24 in a fluid-tight manner. In this respect, the jacketing 24 extends over a length L.sub.24 so that a driving flow Q.sub.T driven by the rotor is bundled and exits the housing 23 at the proximal end of the jacketing 24 and flows in the direction of the outflow openings 29 which are arranged in an outflow hose 25.

(20) The jacketing 24 in the embodiment of the pump arrangement 20 forms the first section of the sheath; the outflow hose 25 forms the second section of the sheath. The distal end of the outflow hose is fastened to the housing 23 and is further distal than the proximal end of the sheath 24.

(21) The sheath 34 converges from the region of the rotor 21 in the proximal direction. The lumen formed by the sheath 24 thus has a cross-sectional area A.sub.1D in the region of the rotor 21 which is larger than the cross-sectional area A.sub.1P of the proximal end of the sheath 24. A nozzle effect is hereby produced which accelerates the driving flow Q.sub.T in accordance with the principle of the Venturi tube so that it flows in the direction of the outflow openings 29 at a higher flow speed at the proximal end of the sheath 24. The intake passage 26 which is accessible through the inlets 27 is located between the sheath 24 and the outflow hose 25. It can be recognized from FIG. 4 that a plurality of inlets 27 are present, with the inlets being designed as circular sections of the outflow hose in the region of its distal end. Due to the reduced pressure in the region of the exiting driving flow Q.sub.T an intake flow Q.sub.s is sucked through the inlet 27 and the intake passage 26 and flows into the flow passage S, which transports the total conveyed flow to the outflow openings 29.

(22) A support ring 28 which is stable in shape in the working state of the pump is located radially peripherally proximal to the inlets 27 and the outflow hose 25. A suction of the surface of the outflow hose 25 to the sheath 24 due to the occurring intake flow is thus prevented. The intake passage 26 thus remains open and further fluid is sucked through the intake passage 26, caused by the driving flow Q.sub.T, into the flow passage S.

(23) A further embodiment of the pump arrangement in accordance with the invention is shown in FIG. 5a. The pump arrangement 30 includes a rotor 31 which is supported at both sides, i.e. distal and proximal, at an axle 32. The rotor 31 is arranged in a housing 33 which is sectionally jacketed by a PU coating 34. The PU coating 34 in this respect extends over a length L.sub.34 up to a region disposed proximal to the proximal end of the rotor 31. The housing 33 has a constriction 33a and expands proximal of the constriction 33a to form a bulge 33b. In the region of the bulge 33b, the outflow hose 35 is connected to the housing 33 with material continuity. The bulge 33b and the constriction 33a are spaced apart from one another, measured along the axis 32, by a spacing d which amounts to around 0 to ¼ of the diameter of the constriction 33a. In this respect, the spacing d is selected so that due to the driving flow Q.sub.T exiting the proximal end of the PU coating 34 and driven by the rotor 31, an intake flow Q.sub.s is sucked in through the inlet opening 36 resulting between the PU coating 34 and the outflow hose 35. The driving flow Q.sub.T exiting the jacketing is flowed out at a pressure P.sub.1. A pressure P.sub.2 applies outside the jacketing 34 which is lower than the pressure P.sub.1. An intake flow Q.sub.s is sucked into the inlet opening 36 due to this pressure difference and is transported through the outflow hose toward the outflow opening 39 where it is expelled as a total current Q.sub.A at a pressure P.sub.3 which is greater than the pressure P.sub.2. The total flow Q.sub.A is in this respect lower than the driving flow Q.sub.T.

(24) Even if the flow passage S, which extends between the intake opening distal of the rotor 31 and the outflow opening 39, is permeable for fluid between the proximal end of the PU coating 34 and the distal end of the outflow hose 35, the inflow opening 36 nevertheless opens into the flow passage which is defined by the flow course of the driving flow. If the driving flow is correspondingly high, it enters practically directly into the outflow hose.

(25) It is possible due to the inlet opening present in addition to the intake opening disposed distal of the rotor 31 that a partial flow of the total flow Q.sub.A exiting at the outflow opening 39 does not pass the rotor 31 and there is thus no risk of blood damage by the rotor 31.

(26) The embodiment of the pump arrangement 30 of FIG. 5a is shown again schematically in FIG. 5b. It can be recognized here that the distal end of the PU coating 34 has a cross-sectional area A.sub.10 which is larger with respect to the cross-sectional area A.sub.1P which is present at the proximal end of the PU coating 34. The lumen surrounded by the PU coating 34 thus converges, which has the consequence of an efficiency improvement. The cross-sectional area A.sub.2D of the lumen of the outflow hose 35 is in turn larger than the cross-sectional area A.sub.1P. An inlet opening 36 is thus defined at least by the region of the cross-sectional area A.sub.2D which remains after the subtraction of the cross-sectional area A.sub.1P. Said inlet opening in turn opens into the flow passage S.

(27) A further embodiment of a pump arrangement is shown in FIG. 6. In this respect, a detailed description of the axle and of the pump drive is dispensed with. The pump arrangement 40 includes a rotor 41 as well as a first section 42a and a second section 42b of a sheath. The intake opening 43 which supplies fluid to the pump 41 is located at the distal end of the first section 42a. The fluid supplied to the pump 41 is accelerated and is expelled as a driving flow Q.sub.T at the proximal end of the first section 42a. The second section 42b is composed of a flexible region 420b which is connected to a compressible sleeve 421b which is of stable shape and is rigid in the working state of the rotor. The compressible sleeve 421b is connected to the first section 42a by means of plastic threads or wires 422b. The cross-section extending in converging manner from the distal end of the sleeve 421b to the proximal end of the sleeve 421b has the effect in conjunction with the driving flow Q.sub.T of sucking in an intake flow Q.sub.s through the inlet opening 45 which is formed between the sleeve 421b and the first section 42a, with the intake flow Q.sub.s being combined with the driving flow Q.sub.T and, in the flow passage S, flowing out of the outflow opening 44 as the total flow Q.sub.A. It is in turn obvious from FIG. 6 that the inlet opening 45 opens into the flow passage S.

(28) A further embodiment of a pump arrangement is shown in FIG. 7. The pump arrangement 50 includes a pump 51 which is formed as an axial-flow pump having a rotor. Furthermore, a sheath 52 is present which can be divided into a first section 52a and into a second section 52b. In this respect, the first section and the second section are connected to one another with material continuity or are manufactured in one piece. An intake opening 53, which supplies fluid to the rotor, is located at the distal end of the sheath 52 so that a driving flow Q.sub.T is conveyed in the working state of the rotor. The driving flow Q.sub.T is conveyed in the direction of the outflow opening 54. An inlet opening 55 through which an intake flow Q.sub.s effected by the driving flow Q.sub.T can enter into the flow passage S defined by the sheath 52 is located between the first section 52a and the second section 52b. The special feature of this embodiment is that the sheath 52 is made in one piece, in contrast to the previously shown embodiments in which the first section represents a separate component with respect to the second section.

(29) Some different geometries of entries of the inlet openings should be shown with respect to FIGS. 8a-c.

(30) A cross-section of the embodiment of FIG. 6 is shown in FIG. 8a. What can be seen is the intake opening 543 with a cross-sectional area A.sub.1P. Disposed proximal thereto, i.e. further into the plane of the drawing, the sleeve 421b is located with the cross section A.sub.2D measured at its widest periphery. The plastic threads 422b connect the sleeve 421b to the first section 42a.

(31) The embodiment of FIG. 5a is shown in FIG. 8b. The intake opening 33 can be recognized which is defined by the PU coating 34. The PU coating 34 simultaneously defines a lumen which has a cross-sectional area A.sub.1D in the region of the rotor. In addition, the axle 32 can be recognized at the center of the intake opening 33. Proximal to the rotor (cf. FIG. 5a), the housing 33 which is formed by threads, wires or struts of Nitinol converges to a cross-sectional area A.sub.1P which is defined by the constriction 33a. At proximal, the housing 33 widens to form a bulge 33b, with the outflow hose 35 being connected to the housing in the region of the bulge. It can clearly be recognized with reference to the representation shown in FIG. 8b that the region 36 disposed between the outflow whose 35 and the PU coating 34 serves as an inlet opening for an intake flow.

(32) In FIG. 8c, the embodiment of FIG. 4 is shown. In this respect, the cross-section is shown at the level of the support ring 28. The lumen defined by the jacketing 24 of the first section and having the cross-sectional area A.sub.1D can be recognized. The intake passage 26 through which additional fluid is sucked in, driven by the driving flow running through the lumen of the jacketing 24 in the proximal direction, is located between the jacketing 24 and the outflow hose 25. The outflow hose 25 has a cross-sectional area of A.sub.2D in this region. The support ring 28 can clearly be recognized, as can the connection struts 28a which connect the support ring to the jacketing 24. The support ring is composed of a plurality of segments 28b which can be brought into a folded state for introduction of the pump arrangement with the aid of a catheter.

REFERENCE NUMERAL LIST

(33) 1, 10, 20, 30, 40, 50 pump arrangement 2 blood vessel 3 ventricle 4 vessel wall 5 heart valve 6 vessel valve 11, 41, 51 pump 12, 42, 52 sheath 12a, 42a, 52a 1st section of the sheath 12b, 42b, 52b 2nd section of the sheath 13, 43, 53 intake opening 14, 44, 54 outflow opening 15 inlet opening 16 proximal end of the 1st section 17 region of pressure drop 21, 31 rotor 22, 32 axle 23, 33 housing 24, 34 jacketing L24,-L34 length of the jacketing 25, 35, 420b outflow hose 26, 36 intake passage 27 inlets 28 support ring/spacer 33a constriction 33b bulge 421b sleeve 422b spacer Q.sub.T conveyed flow Q.sub.s intake flow Q.sub.A total flow A.sub.1, A.sub.2, A.sub.1D, A.sub.1P, A.sub.2D cross-section