FLUID PUMP CHANGEABLE IN DIAMETER, IN PARTICULAR FOR MEDICAL APPLICATION

Abstract

The invention relates to a fluid pump device, in particular for the medical application, with a compressible pump housing and rotor, as well as with an actuation means which runs in the sleeve and on whose end the fluid pump is arranged. In order to utilize all possibilities of a space-saving arrangement of the respective pump housing of the rotor, which is compressible per se, and as the case may be, a bearing arrangement, the mentioned elements are displaceable to one another in the axial direction compared to an operation position. In particular these elements may be end-configured by way of an axial movement of the drive shaft after the assembly.

Claims

1-17. (canceled)

18. An intravascular fluid pump device comprising: a pump housing having an open distal inflow end, the pump housing being expandable into an expanded state and compressible into a compressed state; a drive shaft having a proximal drive side end and a distal portion; and a radially compressible rotor coupled to the distal portion of the drive shaft, wherein each of the radially compressible rotor and the drive shaft are laterally displaceable at least relative to the pump housing from a first position to a second position, and wherein, in the first position, the radially compressible rotor is at least partially disposed exterior to the pump housing, and, in the second position, the radially compressible rotor is disposed within the pump housing.

19. The fluid pump device of claim 18, wherein, when the pump housing is in the compressed state, the pump housing is sized for percutaneous insertion into a vascular system of a patient.

20. The fluid pump device of claim 18, wherein the distal portion of the drive shaft is configured to transmit torque and rotate the radially compressible rotor relative to the pump housing.

21. The fluid pump device of claim 18, further comprising a fixation element carried on the open distal inflow end of the pump housing, the fixation element comprises a first fixation ring and a second fixation ring that is coaxially positioned with the first fixation ring on the open distal inflow end of the pump housing, wherein a plurality of pairs of structures connect the first fixation ring and the second fixation ring.

22. The fluid pump device of claim 21, wherein each structure in the plurality of pairs of structures is a connection bar.

23. The fluid pump device of claim 21, further comprising a bearing assembly coupled to the distal portion of the drive shaft, wherein, in the second position, a portion of the bearing assembly is engaged with the fixation element and cooperates with the fixation element to rotatably mount the radially compressing rotor to the pump housing and center the drive shaft with the pump housing.

24. The fluid pump device of claim 23, wherein the bearing assembly comprises a hub having a central bore that receives the drive shaft.

25. The fluid pump device of claim 24, wherein the portion of the bearing assembly comprises a plurality of struts extending from the hub, wherein each strut of the plurality of struts is received between one pair of the plurality of pairs of structures.

26. The fluid pump device of claim 25, wherein when each of the plurality of struts are received between one of the plurality of pairs of structures, the plurality of struts form an inflow cage at the open distal inflow end of the fluid housing.

27. The fluid pump device of claim 26, wherein the plurality of struts are pivotable relative to the hub such that the bearing assembly is compressible.

28. The fluid pump device of claim 23, wherein the bearing assembly is positioned on the drive shaft at a position distal of the radially compressible rotor.

29. The fluid pump device of claim 18, wherein the radially compressible rotor is laterally displaceable relative to the pump housing by actuating the drive shaft along a longitudinal direction.

30. The fluid pump device of claim 29, further comprising an actuation device configured to actuate the drive shaft.

31. The fluid pump device of claim 18, further comprising a catheter having a distal end coupled to the pump housing, wherein the radially compressible rotor and the draft shaft are displaceable relative to the pump housing and the catheter in a longitudinal direction.

32. The fluid pump device of claim 31, wherein the drive shaft is at least partially disposed within the catheter.

33. The fluid pump device of claim 18, wherein the pump housing comprises a membrane covering an elastic framework.

34. The fluid pump device of claim 33, wherein the membrane is made of a polyurethane.

35. The fluid pump device of claim 33, wherein the elastic framework is made of a memory alloy or a plastic.

36. The fluid pump device of claim 18, wherein the radially compressible rotor and the drive shaft are laterally displaceable relative to each other.

37. The fluid pump device of claim 18, wherein the radially compressible rotor comprises at least one compressible helical delivery blade.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0050] FIG. 1 a schematic overview of a fluid pump device, wherein the pump is inserted into a heart chamber,

[0051] FIG. 2 a three-dimensional picture of a pump rotor,

[0052] FIG. 3 a lateral view of the pump housing, of the rotor and of a bearing arrangement,

[0053] FIG. 4 a lateral view of the pump housing with a rotor located therein,

[0054] FIG. 5 a detail of the pump housing in a three-dimensional representation,

[0055] FIG. 6 a bearing arrangement of FIG. 6 in a front view,

[0056] FIG. 7 the bearing arrangement of FIG. 6 in a front view,

[0057] FIG. 8 a further bearing arrangement,

[0058] FIG. 9 a bearing arrangement as from FIG. 8, in a compressed condition,

[0059] FIG. 10 a further bearing arrangement in a lateral view,

[0060] FIG. 11 the proximal end of a drive shaft with a coupling to a rotation drive,

[0061] FIG. 12 another design of the proximal shaft end, with another coupling to a drive,

[0062] FIG. 13 an arrangement without a bearing at the distal end of the rotor, in the condition staggered in the longitudinal direction,

[0063] FIG. 14 the arrangement of FIG. 13, in the operating condition, and

[0064] FIG. 15 a further development of the arrangement according to FIGS. 13 and 14.

DETAILED DESCRIPTION

[0065] FIG. 1 shows a heart chamber, which is connected to a blood vessel 2, into which blood is to be pumped. For supporting the pump activity, a fluid pump 3 is introduced into the heart chamber 1, which there sucks blood and pumps this into the blood vessel 2.

[0066] A catheter 4 is introduced through a lock 5 into the blood vessel 2, through which lock the catheter may also be pulled out again. The catheter 4 at its distal end carries the pump 3 in the form of a pump housing 6 connected to the catheter, and a rotor 7. The rotor 7 is rotatably mounted on a drive shaft 8 and comprises delivery elements, which on rotation suck the blood in the direction of the arrows 9 or eject it in the direction of the arrows 10 into the blood vessel 2. For this, the delivery elements in the shown representation, which shows the explained position of the fluid pump, have a helically arranged delivery blade surface.

[0067] The construction of the pump housing and the rotor will be dealt with in more detail further below.

[0068] The drive shaft 8 runs within the catheter, which forms a sleeve in the context of the invention and is driven by the drive 11, which is accommodated in a housing 12. The drive shaft thereby may form an actuation means. The drive elements are only schematically shown in FIG. 1 and are explained further below likewise, in a more detailed manner.

[0069] FIG. 2 in detail shows a pump motor with two helical delivery blades 13, 14, which are offset to one another by 180□ on the periphery of the drive shaft 8. The individual delivery blades consist of spanning elements such as for example struts 13a, 13b, as well as a frame 13c which is tautened with a membrane, for example of polyurethane or polyethylene. The frame and the struts may for example consist of a memory material which assumes its shape dependent on temperature. Then in a compressed form at a first temperature, preferably cooled, such a pump rotor may be introduced into the body of the patient and there may automatically unfold or expand after heating to the body temperature or subsequent further heating.

[0070] However, it is also conceivable to automatically erect the pump rotor by way of a rotation drive in the operation direction, by way of the fluid to be delivered, thus blood in this example, catching in the delivery blades and leading to an erection of the delivery blades by way of the counter pressure of the fluid.

[0071] The constructional shape of the rotor may also differ from that which has been described above, by way of using collapsible or pivotable elements, in order to form a delivery blade surface. The pivotable parts may then usefully be folded onto the drive shaft in the compressed condition.

[0072] The struts 13a, 13b as well as the frame 13c of the pump housing are usefully tautened, but the frame 13c runs in the direction of the pump housing somewhat beyond the tautening and forms a run-in chamfer there, which serves for a simpler displacement of the rotor into the pump housing.

[0073] FIG. 3 shows a pump housing 6, a rotor 7 as well as a bearing arrangement 15, which are distributed distanced to one another axially on the drive shaft 8. This condition remains at least until the mentioned parts are brought within a body of a patient on location.

[0074] Thereafter, the drive shaft 8 which forms an actuation means, may be retracted in the direction of the arrow 15, in order to form a functioning construction unit of a fluid pump by way of a relative displacement of the rotor, pump housing and bearing arrangement.

[0075] On pulling-back the drive shaft 8, firstly the catch 17 abuts the hub 18 of the bearing arrangement 15. With a continued pulling-back of the shaft, the bearing arrangement is carried along and is pressed against the rotor 7. This is likewise carried along and, with the continued pulling back of the drive shaft 8, is pulled into the inside of the pump housing 6. Thereby, the rotor 7 moves so far into the pump housing, until it is completely covered by this.

[0076] The pump housing 6 at its open end carries a fixation ring 19, in which the struts of the bearing arrangement 15 may clamp.

[0077] FIG. 4 shows the pump housing, the rotor and the bearing arrangement in an axially pushed-together form. The fixation ring 19 is described in more detail in FIG. 5. It consists of two individual rings 19a, 19b which are also coaxially positioned to one another and are connected by way of connection bars which are like ladder rungs. In each case, the ends of the struts 20, 21 of the bearing arrangement 15 have space between the connection bars 19c, 19d, so that after the introduction, the bearing arrangement is radially centered there as well as axially positioned with respect to the ring 19. The bearing arrangement is shown schematically in FIG. 6 and comprises a hub 18 and struts 20, 21. The struts 20, 21 are pivotably movably fastened on the hub 18 either by way of a joint or by way of their flexibility.

[0078] If the bearing arrangement is displaced with respect to the pump housing by way of pulling back the drive shaft, then the ends of the struts 20, 21 are applied elastically into the compartments between the bars 19c, 19d of the ring 19. There, the bearing arrangement braces automatically and centers the drive shaft mounted in its hub, with respect to the pump housing 6.

[0079] FIG. 6 shows a long bearing arrangement, with which in each case a significantly long hub piece is arranged in front of as well as axially behind the struts. The bearing arrangement may also be constructed in a shorter manner by way of a hub only being provided on one side of the struts, as is shown in FIG. 8.

[0080] FIG. 7 shows a front view of the bearing arrangement of FIG. 6

[0081] FIG. 9 shows the movement ability of the struts in the compressed condition.

[0082] On introducing the fluid pump device through a blood vessel into a human body, the struts 20, 21 firstly bear snugly on the hub body, as long as the bearing arrangement is still located within the vessel, and is then elastically expanded. This elasticity after the expansion and the axial contraction of the pump elements ensures that the bearing arrangement remains fixed in the ring 19 of the pump housing.

[0083] FIG. 10 shows a further embodiment of the bearing arrangement with a double shaft mounting and specifically in the region of the bearing 22, 23. The struts are formed and radially extended by way of two hub parts 22, 23 of the bearing arrangement approaching one another by way of axially pulling on the drive shaft. The struts on approaching the two hub parts are folded open on one another in a bead-like manner and extend radially away from the drive shaft. With an adequate expansion, these struts may also brace themselves in the ring 19.

[0084] FIG. 11 shows the proximal end of the shaft 8 and its coupling to a drive, which is to permit an axial displacement ability of the drive shaft by 10 to 14 mm, in order after the introduction of the individual elements of the fluid pump to the application location, to be able to pull back the bearing arrangement and the rotor into the pump housing by way of pulling back the drive shaft.

[0085] FIG. 11 in this context represents a gas-tight coupling of the catheter 4, which forms the sleeve for the shaft 8, onto a fluid-tight housing 24. A drive body 25 is located in the housing 24 and has magnet elements 26, 27 on its periphery, which on the cover side may be driven in a changing magnetic field incorporated outside the housing 24. A drive movement is transmitted by way of this in a simple manner via the fluid-tight wall of the housing 24. For example, a second drive body 28 with permanent magnets or electric magnets may rotate outside the housing 24, or windings may be arranged there, which produce a rotating field.

[0086] A bolt 30 is fastened on the base 29 of the housing 24 and carries a thread 31 which is stationary in the axial direction.

[0087] The rotor 25 carries a ring 32 with an inner thread which runs on the thread 31.

[0088] With a rotation of the drive body 25 in the operating direction, by way of the cooperation of inner and outer thread, the drive body 25 is moved in the direction of the arrow 33, by which means the drive shaft 8 is pulled back. The inner ring 32 after completion of the retraction movement of the shaft runs away from the thread 31, and as a result the drive body 25 may rotate axially in a stationary manner. The fluid pump is thus axially pushed together and set into operation.

[0089] FIG. 12 shows another embodiment at the proximal end of the drive shaft 8. In the representation of FIG. 12, only the magnets 26, 27 of the drive body 25 which are located within a fluid tight housing 34 are represented. The drive body 25 may be mounted in the housing in an axially stationary manner and is driven in a rotational manner from the outside. It transmits the rotation movement onto a polygonal piece 35, which is guided in a complementarily shaped opening (lock) 36 in the drive body in a rotationally fixed manner, but axially displaceable manner with respect to this. For example, the lock 36 and the polygonal piece 35 may be designed as a regular octagonal bolt, square bolt or hexagonal bolt.

[0090] The drive shaft 8 is connected in a rotationally fixed manner in its end region 37 to a bush 38. An armature 39 is rotatably received in the bush 38 with an undercut, and the armature does not rotate with the bush 38, but axially fixed this. The armature 39 is provided with a ring 40 through which a pull tape 41 is pulled. If the armature 39 is pulled back manually in the direction of the arrow 42 by way of the pull tape 41, then the armature pulls the bush 38, which may rotate with respect to the armature, in the direction of the arrow 42 a little out of the catheter 4, so that the necessary displacements may take place in the region of the fluid pump. The drive body 25 may be driven during this without upsetting the pulling movement.

[0091] The armature 39 may be fastened in a fluid-tight manner to the housing 34 by way of a bellows or a sealingly connected membrane 43, in order to ensure the sealedness of the housing 34.

[0092] FIG. 13 shows a pump housing 53 which comprises a membrane which is spanned over a framework and ends in an open manner towards the distal end. The drive shaft 52 or its stiffened extension 52 is displaced distally to the pump housing, just as the rotor 54b. Two bearings 51, 51a are represented on the proximal side of the housing 53 and of the rotor, and are axially distant to one another and provide the drive shaft or its stiffened end with a particularly stable mounting, which also prevents a lateral swinging-open of the unmounted end on the other side of the bearings 51, 51a.

[0093] Instead of two separate bearings, one may also select an individual stable and preferably long bearing on the proximal side of the rotor. A simplified assembly and improved displacement ability with a greater running stability is realized by way of this.

[0094] FIG. 14 shows the arrangement of FIG. 13 in the operating condition in which the shaft is pulled to the proximal end and the rotor 54b is pulled into the housing 53.

[0095] With longer flexible shafts, it makes sense to pull the rotor with locked bearings into the housing, hi FIG. 15, the housing indentation 67 prevents the shaft with the locked bearings from being pulled too far inwards. The housing indentation 68 is thus not as deep as the housing indentation 67 and permits a pulling-in of the bearing combination. An axial displacement of the rotor combination to the outside is no longer possible by way of the snap-in. Bearings 64a+b are loose on the shaft 65. Locking sleeves 66a-c are connected to the shaft in a fixed manner.

[0096] Thus, in all designs, an efficient manner of the drive with a displacement ability of the drive shaft is provided by way of the invention, wherein the displacement of the drive shaft, for completing the fluid pump after introduction to the place of operation, is used in an optimal manner by way of an axial relative displacement of the rotor, bearing arrangement and pump housing.