Pump device having a detection device

Abstract

The invention relates to a pump device having a pump (8) and an energy supply device (5, 18), wherein the pump has a conveying element (9, 11) which conveys a fluid by means of supplied energy, wherein the pump has a transport state and an operating state, and wherein at least one first element (9, 9a, 10, 10′, 11) of the pump has a different shape and/or size in the transport state than in the operating slate. The operating safety of such a pump device is increased by a detection device (12, 20, 21, 22, 23, 24, 25, 27, 28, 29) which detects whether at least the first element is in the operating state with respect to shape and/or size by means of a sensor.

Claims

1. An intravascular pump device, comprising: a first catheter having a proximal end and a distal end; a pump head configured to compress into a compressed state and expand into an expanded state, wherein the pump head is configured to move within the first catheter and the pump head elastically expands into the expanded state upon release from the first catheter; the pump head having a rotor with impeller blades, the impeller blades being elastically compressible and automatically elastically expandable, wherein the impeller blades are configured to convey a fluid by a supplied energy; and a sensor configured to produce an output signal indicative of a load on the rotor.

2. The pump device of claim 1, wherein the sensor is configured to produce the output signal by detecting electrical current driving the rotor.

3. The pump device of claim 1, the intravascular pump device configured to modify a transfer of the supplied energy based on the output signal from the sensor.

4. The pump device of claim 3, wherein the intravascular pump device is configured to interrupt transfer of the supplied energy based on the output signal from the sensor.

5. The pump device of claim 2, wherein the detected electrical current is higher when the pump head is not in the expanded state than when the pump head is in the expanded state.

6. The pump device of claim 2, further comprising: a flexible drive shaft having proximal and distal ends and being coupled to the rotor at the distal end of the drive shaft; and a drive comprising a motor configured to drive the flexible drive shaft to deliver energy to the rotor.

7. The pump device of claim 6, further comprising a second catheter configured to move through the first catheter.

8. The pump device of claim 7, wherein the second catheter is configured to surround the flexible drive shaft.

9. The pump device of claim 7, wherein the second catheter extends along the flexible drive shaft.

10. The pump device of claim 6, wherein the motor is configured to prevent a rotation of the flexible drive shaft when the output signal of the sensor is greater than a threshold value.

11. The pump device of claim 6, wherein the sensor is positioned at the motor.

12. The pump device of claim 1, wherein the sensor is positioned at a motor.

13. The pump device of claim 12, wherein the motor is proximal to the pump head.

14. The pump device of claim 1, wherein the impeller blades comprise an elastic material.

15. The pump device of claim 1, wherein the first catheter is configured to compress the pump head when the pump head is inserted into the first catheter.

16. The pump device of claim 1, wherein the pump head is configured to automatically expand into the expanded state upon release from the first catheter.

17. The pump device of claim 1, wherein the pump head is configured to expand by an application of a force on the pump device.

18. The pump device of claim 17, wherein the pump head is configured to expand by an application of a fluid counter-pressure on the pump device.

19. The pump device of claim 1, further comprising a second sensor configured to indicate movement of the pump head in a longitudinal direction.

20. The pump device of claim 19, wherein the second sensor is positioned on a second catheter, the second catheter configured to move through the first catheter.

21. The pump device of claim 1, further comprising a second sensor positioned on a second catheter, wherein the second catheter is configured to move through the first catheter.

22. The pump device of claim 1, wherein the pump device is configured such that the pump head is positioned in a left ventricle of a heart.

Description

(1) The invention will be shown and subsequently described in the following with reference to an embodiment in a drawing. There are shown

(2) FIG. 1 schematically, a heart catheter pump on being pushed through a blood vessel into a ventricle;

(3) FIG. 2 the pump of FIG. 1 after the reaching of the ventricle and after the expanding;

(4) FIG. 3 a first signal processing of detector signals;

(5) FIG. 4 a second processing of detector signals;

(6) FIG. 5 a processing of detector signals with an additional control of the drive device;

(7) FIG. 6 a signal processing in which the connection between the drive device and the pump is interrupted from case to case;

(8) FIG. 7 a detection device which is arranged at the drive device;

(9) FIG. 8 a pump in compressed form;

(10) FIG. 9 the pump of FIG. 8 in expanded form;

(11) FIG. 10 a pump which is positioned in compressed form in a ventricle;

(12) FIG. 11 a detection device of a pump which measures an electric resistance;

(13) FIG. 12 a detection device which measures the resistance of a wire spanning around a pump;

(14) FIG. 13 a detection device similar to that of FIG. 12 with an interrupted conductor;

(15) FIG. 14 a pump in the compressed state, surrounded by a non-conductive path;

(16) FIG. 15 the pump of FIG. 14 in an at least partly expanded state with a closed conductor path;

(17) FIG. 16 schematically, a pump in a longitudinal section whereas it is compressed in a hollow catheter at the end of said hollow catheter; and

(18) FIG. 17 the pump of FIG. 16 outside the catheter in an expanded state.

(19) FIG. 1 schematically shows a ventricle 1 into which a blood vessel 2 opens through which a hollow catheter 4 is introduced by means of a sluice 3. The hollow catheter has a rotating shat 5 in its hollow space which is drivable at high revolutions, typically more than 10,000 revolutions per minute, by means of a motor 6.

(20) The shaft 5 drives a pump 8 at the distal end 7 of the hollow catheter, said pump being compressed by the hollow catheter in the still compressed state at the end of the hollow catheter in the representation of FIG. 1.

(21) The pump can, for example, be pushed out of the end of the hollow catheter 4 into the ventricle 1 by means of the shaft 5 or by means of further elements not shown. The state which thus arises is shown in FIG. 2 where the pump 8 is shown in the expanded form. A rotor 9 is thus shown in schematic form in the interior of a pump housing 10.

(22) The rotor 9 has impeller blades 11 which project radially from a hub and which are rolled up, folded up or otherwise compressed in the compressed state of the pump.

(23) In the design shown in FIG. 2, the pump 8 is ready for operation, i.e. it is in the expanded state and can convey blood by rotation of the rotor. In FIG. 1, in contrast, the pump 8 is shown in the transport state, i.e. it is compressed within the hollow catheter 4.

(24) The transition from the compressed form of the pump to the expanded form can take place, for example, when the outer compressive forces are removed, by the inherent elasticity of the pump housing 10 and of the rotor 9.

(25) Additional manipulation elements can, however, also additionally be provided such as pulls which extend along the hollow catheter 4 at its outer side or in the lumen and which can effect the folding open and expanding of the pump by the application of a pulling force or pressure onto the pump.

(26) The pump can ultimately, for example, also be expanded in that the rotor is rotated slowly so that, for example, the impeller blades 11 are erected by the fluid counter-pressure of the blood which is trapped in said impeller blades.

(27) The pump housing 10 can likewise be inflated by a slight overpressure which is generated by the rotor.

(28) It is also conceivable to equip the pump with inflatable hollow spaces, in that, for example, the pump housing 10 is produced as a double-wall balloon and the rotor likewise has inflatable hollow spaces both in the impeller blades and, optionally in the hub, wherein the individual elements of the pump in this case have to be connected to a controllable pressure source via hydraulic or pneumatic lines. The named components can also comprise a foam which adopts its expanded form automatically after the removal of compressive forces.

(29) It is decisive for an increased operating security in this respect that the expanded state of the pump is also checked and detected so that, for example, a treating physician can decide whether the pump can be put into operation.

(30) For this purpose, different kinds of sensors can be provided which will be described in more detail further below.

(31) It is shown with reference to FIG. 3 how a signal coming from such a sensor can be processed.

(32) The sensor is marked by 12 in FIG. 3. It delivers a signal to a decision-making device 13 which decides on the basis of the sensor signals whether the pump is expanded or not or whether a specific element of the pump is expanded. If the expanded state has been reached (Yes), the signal path 14 is selected. If the expanded state has not been reached (No), the signal 15 is terminated. Depending on what the state of the pump is, a signal, in FIG. 3, for example, a light signal, is output when the expanded state has been reached or it is suppressed as long as the expanded state has not yet been reached.

(33) The light signal arrangement can also be exactly the opposite so that a light signal is output as long as the expanded state has not been reached and it is extinguished as soon as the expanded state has been reached.

(34) Instead of light signals, other types of signals can also be emitted such as acoustic signals.

(35) It is shown in FIG. 4 that, in accordance with the same structure as in FIG. 3, a switch 16 to a signal element is interrupted on the reaching of the expanded state and a corresponding adoption of the signal state 14 (Yes), whereas the same switch element or also a different switch element is closed when the signal state 15 (No) is adopted.

(36) Different elements which achieve specific desired effects can also be connected to the corresponding switches 16 instead of a signal element.

(37) A constellation is shown in FIG. 5 in which a further switch 17 is provided in series with a switch 16 which is actuated in dependencdt on the signal, and said further switch is actuable by hand and results in the actuation of the drive 18 of the pump This has the consequence that in the event that the expanded state is reached (Yes), the signal 14 is output and the switch 16 is closed. The drive can thus be switched on by actuating the switch 17.

(38) As long as the signal for the reaching of the expanded state has not been given (No), shown by the signal 15, the switch 16 remains open, as shown in the lower half of FIG. 6, so that the switch 17 can admittedly be actuated, but the drive 18 is thereby not set into motion. The drive 18 is thus blocked by means of the sensor 12 or by means of its signal processing.

(39) In FIG. 6, a variant of the circuit shown in FIG. 3 is described in which a switch 19 which permits or blocks the transfer of energy from the drive 18 to the pump 8 is actuated by the signal processing. If the expanded state of the pump has been reached, characterized by the signal 14, the switch 19 is closed and the energy can move from the drive 18 to the pump. As long as the expanded state has not been reached, characterized by the signal 15, the switch 19 remains open and the effect of the drive does not reach the pump.

(40) The examples for a drive control of FIGS. 5 and 6 can also be combined with a signal processing in accordance with the examples of FIGS. 1 to 4 such that both a signal which can be perceived outside the body appears or is extinguished and the energy supply of the drive device is switched free or blocked.

(41) The switch 19 can, for example, be configured as an electric switch, but also as a pneumatic or hydraulic valve which is arranged in the powertrain.

(42) It can also be a coupling which blocks the transmission of the torque via the shaft in that the coupling changes into the disengaged state in which no torque is transmitted.

(43) FIG. 7 schematically shows the arrangement of a sensor 20 directly at the drive 18, with the sensor 20, for example, measuring the current flowing through the drive or measuring the load of the drive in another manner.

(44) If the pump is not yet in the expanded state, the load of the drive becomes higher than in the expanded state since the pump is either unable to be moved at all or can only be moved with large friction losses.

(45) The load is detected by the sensor 20 and is compared by means of a processing device 21 as part of the detection device with reference values or reference patterns, with the device 21 being able to influence the drive 18, for example being able to switch it off when it is detected that the expanded state has not yet been reached.

(46) The sensor 20 is in this case typically arranged remote from the pump and closer to the drive, i.e. in the example shown in FIGS. 1 and 2, in the proximity of the electric motor 6 or its current source.

(47) Provision can also be made in this respect that the corresponding motor, either an electric motor or, for example, also a microturbine, can be arranged at the distal end of the hollow catheter 4 so that in this case the sensor 20 is also arranged there.

(48) In FIG. 8, a pump 8 is shown schematically in the compressed state with a folded-together housing 10 and a rotor 9 whose impeller blades 11 are likewise compressed, for example folded into the hub 9a.

(49) Strain gages 22, 23, 24 are shown, with the strain gage 22 being arranged on an impeller blade, the strain gage 23 in the starting region of an impeller blade at the hub 9a and the strain gage 24 outside at the housing 10.

(50) The strain gages are in each case stuck on and register changes in shape and size of the carrier material. They are each connected via lines to an evaluation device 25 which registers the extent of shape changes during the expansion process of the pump. The signals of the individual strain gages can be combined, with the logic of this combination being able to have a different design. The reaching of the operating state can, for example, only be signaled when all the strain gages report an expansion of the respective element monitored by them or when at least two of these elements or even already a single element reports the reaching of the expanded state. A signal to the drive 18 is accordingly output.

(51) The pump of FIG. 8 is shown in an expanded state in FIG. 9.

(52) FIG. 10 shows the end 7 of a hollow catheter 4 in which a pump 8 is compressed. The pump 8 is connected to the motor 6 by means of the shaft 5 through the hollow catheter 4. Both the housing 10 and the rotor 9 having the impeller blades are compressed.

(53) The housing 10′ is shown by dashed lines in a state which is reached after the expansion of the pump. An introduction cone 26 is moreover shown via which the pump 10 is moved in and is radially compressed there on the pulling into the hollow catheter 4 before the removal from the patient body.

(54) Two sensors 27, 28 are provided within the hollow catheter 4 which signal whether the pump is in the region of the hollow catheter represented and monitored by them or whether it has already been moved out of it. In the representation of FIG. 10, the region of the sensor 27 has already been passed by the pump, but the sensor 28 still signals that the pump is compressed in this region. After the moving out of the hollow catheter, the sensor 28 will report that it is free and that the pump has been moved out of the hollow catheter and has thus expanded. The corresponding signals are processed in a signal processing device 25 and are optionally forwarded to the drive 18.

(55) FIG. 11 shows a sensor 29 which is designed as a resistance measuring sensor and which is connected in series with a current sourced 30 and is connected via two lines 31, 32, to the pump housing 10 and to an impeller blade 11. Both the housing 10 and the impeller blade can, for example, comprise an at least partly conductive material or can be coated with such a material so that the circuit is closed over the lines 31, 32, over the sensor 29 and between the impeller blade 11 and the pump housing 10 as soon as the impeller blade 11 contacts the housing 10.

(56) In this case it would be signaled that the pump is not in the operating state.

(57) As soon as the contact between the impeller blade 11 and the housing 10 is cancelled, the detection device signals the reaching of the expanded state.

(58) FIG. 12 represents a resistance monitoring of a closed wire ring 33 which is spanned around a compressed pump 10. If the wire tears on the expansion of the pump, the resistance in the ring is doubled since one of the current paths is interrupted. This is registered by the sensor 29 and the expanded state is signaled accordingly.

(59) FIG. 13 shows a similar device to FIG. 12 with a ring conductor 34 which is interrupted between the feed lines 35, 36 and which is integrated, for example, into a closed insulation ring. If the insulation ring breaks at a point at which the ring conductor 34 extends, the current path is interrupted by the ring conductor, which is registered by the sensor 29.

(60) FIG. 14 shows a similar apparatus to FIG. 13 with a compressed pump 10, with the current circuit of the ring conductor 33a, however, unlike in FIG. 13, first being open in the transport state and being closed in the expanded state of the pump, that is, in the operating state. The advantage of this variant lies in the fact that the expanded state is only indicated when the ring conductor itself has no defect. In the embodiment in accordance with FIG. 13, a defective ring conductor, interrupted unintentionally, would possibly also indicate the reaching of the expanded state when this has not (yet) been reached. In an embodiment in accordance with FIG. 14, this would not be necessary, which provides additional security against malfunction.

(61) FIG. 15 shows the pump 10 with the apparatus from FIG. 14 in the expanded state with a closed ring conductor 33b.

(62) FIG. 16 shows an apparatus similar to that in FIG. 10 in the transport state, but configured so that a switch 37 is arranged at the proximal end of the catheter 38. In this respect, the length of the catheter 38 in relation to the length of the hollow catheter 39 is dimensioned so that the pump head 40 has already fully adopted the expanded state (that is has left the hollow catheter 39) when the proximal end 41 of the hollow catheter 39 actuates the switch 37 (cf. FIG. 17). To avoid unwanted triggering of the switch 37, it is advantageously configured or arranged so that a triggering of the switch is not possible manually during the manipulation. The switch 37 can be arranged outside a patient's body with a sufficient length of the catheters 38, 39.

(63) FIG. 17 shows the apparatus of FIG. 16 in the operating state.

(64) In FIG. 17, an optical monitoring device is also shown by way of example for the expanded state supplemented with a proximal light source 100, a prism/beam splitter 102, a light guide 103 and an optical sensor 101. The light guide is conducted up to the pump head, conducts light of the light source 100 to there and conducts reflected light back to the optical sensor 101 depending on the compressed or expanded state.

(65) The described invention serves to increase the operating security of compressible pumps and in particular to lower health risks in the medical sector.