TRANSCUTANEOUS ENERGY TRANSFER SYSTEMS

• US 20150290373A1
• Filed: 04/14/2015
• Published: 10/15/2015
• Est. Priority Date: 04/15/2014
• Status: Active Grant

• Current Assignee: Heartware,Inc. (Medtronic Plc)
• Original Assignee: Heartware,Inc. (Medtronic Plc)
• Inventors: Rudser, John, LaRose, Jeffrey A., Gomez, Ramiro
• Granted Patent: US 10,143,788 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2205/8243 by induction
• CPC Class Codes: A61M 60/178 drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices
• CPC Class Codes: A61M 60/216 including a rotating member acting on the blood, e.g. impeller
• CPC Class Codes: A61M 60/422 the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps
• CPC Class Codes: A61M 60/538 Regulation using real-time blood pump operational parameter data, e.g. motor current
• CPC Class Codes: A61M 60/875 specially adapted for optimising alignment of external and implantable coils
• CPC Class Codes: A61N 1/3787 from an external energy source
• CPC Class Codes: H02J 2310/23 The load being a medical device, a medical implant, or a life supporting device
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge

Abstract

The present disclosure relates to an improved transcutaneous energy transfer (TET) system that generates and wirelessly transmits a sufficient amount of energy to power one or more implanted devices, including a heart pump, while maintaining the system'"'"'s efficiency, safety, and overall convenience of use. The disclosure further relates one or more methods of operation for the improved system.

Claims

1. A transcutaneous energy transfer system comprising:

(a) an internal component comprising a power-consuming device and an internal coil electrically connected to the power-consuming device, the internal component being adapted for mounting within the body of an animal;

(b) an external coil adapted for mounting outside of the body;

(c) a coupling detection circuit operative to provide an indication of whether or not the external coil is electromagnetically coupled to the internal coil; and

(d) a drive circuit operative to apply a power-level alternating potential to the external coil responsive to an indication from the coupling detection circuit that the external coil is electromagnetically coupled to the internal coil, and to apply a test-level alternating potential less than the power-level alternating potential to the external coil when the not applying the power-level alternating potential.

2. A system as claimed in claim 1 wherein the drive circuit is operative to cease application of the power-level alternating potential to the external coil in response to an indication from the coupling detection circuit that the external coil is not electromagnetically coupled to the internal coil.

3. A system as claimed in claim 1 wherein the drive circuit is operative to apply the test-level alternating potential intermittently when the drive circuit is not applying the power-level alternating potential.

4. A transcutaneous energy transfer system comprising:

(a) an internal component adapted for mounting within the body of an animal, the internal component including;

an internal coil;

an internal device electrically connected to the internal coil for receipt of power from the internal coil; and

a telemetry transmitter operative to send telemetry signals representing one or more parameters relating to operation of the internal component; and

(b) an external component adapted for mounting outside of the body, the external component including;

an external coil;

a telemetry receiver adapted to receive the telemetry signals from the telemetry transmitter; and

a drive circuit operative in a normal mode of operation when the telemetry receiver receives the telemetry signals, and in a safe mode of operation when the telemetry receiver does not receive the telemetry signals, the drive circuit being operative in both the normal and safe modes to apply power to the external coil so that power applied to the external coil will be coupled to the internal coil, the circuit being operative to control the power applied to the external coil at least in part responsive to the telemetry signals when operating in the normal mode.

5. A system as claimed in claim 4, wherein the drive circuit is operative to apply more power to the external coil in the normal mode than in the safe mode.

6. A system as claimed in claim 5, wherein the drive circuit is operative, in the normal mode, to apply an amount of power to the external coil sufficient to operate the internal device and the telemetry transmitter.

7. A system as claimed in claim 4, further comprising a coupling detection circuit operative to provide an indication of whether or not the external coil is electromagnetically coupled to the internal coil, wherein the drive circuit is configured to operate in the safe mode only when the telemetry receiver does not receive the telemetry signals and the coupling detection circuit indicates that the external coil is electromagnetically coupled to the internal coil.

8. A driver for a transcutaneous energy transfer system, the driver comprising:

a primary coil;

a drive circuit operative to supply an electrical current to the primary coil;

one or more sensors operative to measure one of an electrical current and a temperature associated with the drive circuit; and

a control circuit operative to;

compare the measured current or temperature to a corresponding threshold temperature or current value; and

if the measured current or temperature equals or exceeds the corresponding threshold value, stop operation of the drive circuit until a predetermined condition is met.

9. A driver as claimed in claim 8, wherein if the measured temperature exceeds the corresponding threshold temperature value, the control circuit is operative to stop operation of the drive circuit until the measured temperature equals or is less than a predetermined second threshold temperature value.

10. A driver as claimed in claim 8, wherein if the measured current exceeds the corresponding threshold current value, the control circuit is operative to stop operation of the drive circuit until the passage of a predetermined amount of time.

11. A transcutaneous energy transfer system, comprising a driver as claimed in claim 8 and a component driven by the driver, the driven component including:

a secondary coil;

an implanted power-consuming device electrically connected to the secondary coil; and

an implanted power source electrically coupled to the power-consuming device and secondary coil, and configured to store charge sufficient to operate the power-consuming device,

wherein the control circuit is further configured to instruct the implanted power source to supply power to the implanted medical device if the measured current or temperature equals or exceeds the corresponding threshold value.

15. A wireless energy transfer module comprising a driver as claimed in claim 8, wherein the primary coil and the drive circuit are disposed within a common housing.

16. A wireless energy transfer module as claimed in claim 15, wherein the common housing comprises first surface adapted to be mounted outside the body of an animal, a second curved surface opposite the first surface, and a substantially circular sidewall extending in the direction of the primary axis between the first and second surfaces.

17. A wireless energy transfer module as claimed in claim 16, wherein the sidewall extends in the direction of the primary axis about 10 mm.

18. A wireless energy transfer module as claimed in claim 15, further comprising a thermal isolation layer disposed generally axially from the primary coil, the thermal isolation layer providing a thermal barrier between the primary coil and the skin of an animal onto which the wireless energy transfer module is mounted.

12. A driver for a wireless energy transfer system comprising:

a primary coil having a primary axis and a primary conductor extending in a spiral around the primary axis, the primary conductor having an inner end and an outer end, the inner and outer ends of the primary conductor being disposed substantially on a common radial line of the primary axis; and

a drive circuit electrically connected to the inner and outer ends of the primary coil, and operative to drive the primary coil.

13. A driver as claimed in claim 12, wherein the drive circuit is disposed generally axially from the primary conductor, and the inner and outer ends of the primary conductor extend generally axially from the primary conductor towards the drive circuit.

14. A driver as claimed in claim 12, wherein the drive circuit comprises a printed board circuit including one or more capacitors disposed on the printed board circuit and connected to form a resonant circuit with the primary coil.

19. A wireless energy transfer system comprising a driver as claimed in claim 12 and a component driven by the driver, the driven component including:

a secondary coil having a secondary axis and a secondary conductor extending in a spiral around the secondary axis; and

a power-consuming device electrically connected to the secondary coil.

20. A wireless energy transfer system as claimed in claim 19 wherein the secondary conductor has inner and outer ends disposed substantially on a common radial line perpendicular to the secondary axis.

21. A wireless energy transfer system as claimed in claim 19 further comprising an implantable coil housing having a biocompatible exterior surface, the housing containing the secondary coil and having front and rear sides, a front side of the secondary coil facing toward the front side of the coil housing, the coil housing having one or more visually-perceptible indicia differentiating the front and rear sides of the housing.

22. A transcutaneous energy transfer system including:

(a) a driver including a primary coil and a drive circuit operative to drive the primary coil, the primary coil having a primary axis and a primary conductor extending in a substantially flat spiral around the primary axis;

(b) an implantable secondary coil having a secondary axis and a secondary conductor extending in a substantially flat spiral around the secondary axis; and

(c) an implantable energy-consuming device electrically connected to the secondary coil,

each of the primary and secondary coils having an outer diameter at least about 70 millimeters, the driver being operative to drive the primary coil so as to supply at least about 5 watts of power to the energy-consuming device.

23. A system as claimed in claim 22, wherein the driver is operative to drive the primary coil so as to supply at least about 20 watts of power to the energy-consuming device.

24. A driven element for a wireless energy transfer system comprising:

(a) a secondary coil;

(b) one or more capacitors connected in circuit with the secondary coil to form a resonant circuit;

(c) a rectifier connected to the resonant circuit;

(d) a DC-DC converter having an input connected to the rectifier and an output;

(e) one or more power-consuming devices connected to the output of the DC-DC converter; and

(f) a control circuit constructed and arranged to control a characteristic of the DC-DC converter so that as power consumption by the power-consuming devices increases, one of an output voltage or current at the output of the DC converter remains substantially constant.

25. The driven element as claimed in claim 24, wherein the control circuit is constructed and arranged to control a characteristic of the DC-DC converter so that, as power consumption by the power-consuming devices increases, an input voltage of the DC converter increases.

26. The driven element as claimed in claim 24, wherein the control circuit is constructed and arranged to control a characteristic of the DC-DC converter so that, as power consumption by the power-consuming devices increases, an input impedance of the DC converter decreases.

27. An implantable blood pump system comprising:

(a) an implantable coil housing;

(b) a resonant circuit including a secondary coil and one or more capacitors coupled to the secondary coil, the resonant circuit being disposed entirely within the coil housing and having a pair of load terminals;

(c) an implantable rectifier housing separate from the coil housing;

(d) an internal controller circuit including a rectifier and a drive circuit electrically connected to the rectifier, the rectifier being disposed within the rectifier housing;

(e) a first cable extending between the coil housing and the rectifier housing, the first cable having conductors electrically connected between the load terminals of the resonant circuit and the rectifier, whereby only load current passing from the resonant circuit to the rectifier passes along the conductors of the first cable; and

(e) a pump electrically connected to the drive circuit.

28. An implantable blood pump system as claimed in claim 27, wherein the drive circuit is also disposed within the rectifier housing.

29. An implantable blood pump system as claimed in claim 27, wherein the one or more capacitors are arranged in a circular configuration generally axially from the secondary coil.

30. An implantable blood pump system as claimed in claim 27, and further comprising:

an implantable controller housing separate from the implantable blood pump;

an internal controller circuit disposed within the implantable controller housing and electrically connected to the implantable coil via a first electrical cable and to the blood pump via a second electrical cable.

31. A transcutaneous energy transfer system for supplying power to an implantable blood pump implanted within the body of an animal, comprising:

an implantable blood pump as claimed in claim 27; and

an external coil adapted for mounting to the body of the animal opposite the implantable coil housing.

32. A driver for a wireless energy transfer system comprising:

(a) a primary coil;

(b) a drive circuit operative to drive the primary coil;

(c) a detector circuit operative to determine a degree of coupling between the primary coil and a secondary coil, and to determine a realignment direction for which translating the external coil in the realignment direction would increase the degree of coupling; and

(d) a signal output element connected to the detector and arranged to provide a human-perceptible signal representing the degree of coupling and realignment direction determined by the detector circuit.

33. A driver as claimed in claim 32 wherein the detector circuit includes a telemetry receiver operable to receive telemetry signals indicative of power transfer to the secondary coil.

34. A driver as claimed in claim 32 wherein the detector circuit is operable to receive signals from an accelerometer indicative of a direction of movement of the primary coil, and to determine the realignment direction at least partially based on a change in the degree of coupling between the primary coil and a secondary coil and a signal received from the accelerometer.

35. An implantable blood pump comprising:

(a) a substantially flat secondary coil, the secondary coil having a front side and a rear side facing in opposite directions;

(b) an implantable coil housing containing the secondary coil, the coil housing having front and rear sides, the front side of the secondary coil facing toward the front side of the coil housing; and

(c) a blood pump electrically connected to the secondary coil for receipt of power from the secondary coil, the blood pump having at least one flat end, wherein the rear side of the implantable coil housing is adapted to mount to the flat end of the blood pump.

36. An implantable blood pump as claimed in claim 35, further comprising a shield composed of a ferromagnetic or ferrimagnetic material, the implantable coil housing containing the shield, wherein the shield is positioned between the rear side of the implantable coil housing and the secondary coil.