IMPLANTABLE MEDICAL DEVICES AND SYSTEMS HAVING DUAL FREQUENCY INDUCTIVE TELEMETRY AND RECHARGE

• US 20110190852A1
• Filed: 02/02/2011
• Published: 08/04/2011
• Est. Priority Date: 02/03/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Grevious, John J., Denison, Timothy, Anderson, Joel A., Dinsmoor, David A.
• Granted Patent: US 8,909,351 B2
• Time in Patent Office: Days
• US Class Current: 607/60
• CPC Class Codes: A61B 5/0031 Implanted circuitry
• CPC Class Codes: A61N 1/37223 Circuits for electromagnetic coupling
• CPC Class Codes: A61N 1/37229 Shape or location of the implanted or external antenna
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Implantable devices and related systems utilize coils or coil portions of a coil for inductive telemetry at one frequency and recharge at another frequency. The coils or coil portions are included in one or more tank circuits that share at least one node between the coils or coil portions. The recharge application may be provided with variations for aspects including power management and rectification. The telemetry application may be provided with variations for aspects including receiver connectivity for the downlink and coil driving for the uplink.

Claims

1. An implantable medical device, comprising:

a first tank circuit tuned to a first frequency by comprising a first coil portion and a first capacitance, the first coil portion being connected to a first node;

a second tank circuit tuned to a second frequency by comprising a second coil portion and a second capacitance, the second coil portion being connected to the first node;

a receiver with at least one input connected to a node of the second tank circuit;

a battery;

a rectifier between the battery and the first tank circuit; and

medical circuitry electrically coupled to the battery.

2. The implantable medical device of claim 1, wherein the first coil portion and the second coil portion are coil portions of a single coil having a tap that establishes the first node.

3. The implantable medical device of claim 1, wherein the first coil portion and the second coil portion are geometrically oriented so that current of the first tank circuit sums with current of the second tank circuit at the first node.

4. The implantable medical device of claim 1, wherein the receiver is connected across the second coil portion.

5. The implantable medical device of claim 1, wherein the rectifier is a full-wave rectifier.

6. The implantable medical device of claim 5, wherein the rectifier comprises a first pair of diodes allowing current flowing through the first tank circuit in a first direction to be directed to the battery and a second pair of diodes allowing current flowing through the first tank circuit in a second direction to be directed to the battery.

7. The implantable medical device of claim 5, wherein the rectifier comprises a first synchronized switch allowing current flowing through the first tank circuit in a first direction to be directed to the battery and a second synchronized switch allowing current flowing through the first tank circuit in a second direction to be directed to the battery.

8. The implantable medical device of claim 1, further comprising a switch between one side of the rectifier and ground, and a controller setting the switch to an open state to provide full wave rectification and setting the switch to a closed state to provide half wave rectification.

9. The implantable medical device of claim 1, further comprising a recharge limiter in series with the battery.

10. The implantable medical device of claim 9, further comprising a filter capacitor in parallel with the recharge limiter and battery.

11. The implantable medical device of claim 1, further comprising a tank switch that is connected across the second tank circuit, and a controller that comprises logic that closes the tank switch when receiving telemetry signals.

12. The implantable medical device of claim 11, wherein a first input of the receiver is connected to a node of the tank switch.

13. The implantable medical device of claim 12, wherein a second input of the receiver is connected to a node of the second tank circuit that is opposite the node of the tank switch.

14. The implantable medical device of claim 1, further comprising a capacitor low side switch coupled between the second capacitance and ground and an inductor low side switch coupled between the second coil portion and ground.

15. The implantable medical device of claim 14, wherein a first input of the receiver is connected to a node of the capacitor low side switch and second capacitance or to a node of the inductor low side switch and second coil portion and wherein a second input of the receiver is connected to a node of the second tank circuit other than the node of the first input.

16. The implantable medical device of claim 1, wherein a first input of the receiver is connected to the second coil portion opposite the second capacitance and a second input of the receiver is connected to the second capacitance opposite the second coil portion.

17. The implantable medical device of claim 1, wherein a second input of the receiver is connected to ground.

18. The implantable medical device of claim 1, further comprising a circuit pathway including a switch in series with a resistor, the circuit pathway being in parallel with the first coil portion of the first tank circuit.

19. The implantable medical device of claim 18, further comprising a controller that comprises logic to detect an overcharge condition, to set the switch of the circuit pathway to a first state while an overcharge condition is undetected, and to set the switch of the circuit pathway to a second state upon detecting the overcharge condition.

20. The implantable medical device of claim 1, further comprising:

drive circuitry coupled to opposite sides of the second tank circuit; and

a controller in electrical communication with the drive circuitry, the controller comprising logic to control the drive circuitry to ring the second tank circuit when sending telemetry signals and to not ring the second tank circuit when receiving recharge energy on the first tank circuit.

21. A medical system, comprising:

an external device comprising;

a telemetry module;

a controller that sends telemetry signals through the telemetry module; and

an implantable medical device comprising;

a first tank circuit tuned to a first frequency by comprising a first coil portion and a first capacitance, the first coil being connected to a first node;

a second tank circuit tuned to a second frequency by comprising a second coil portion and a second capacitance, the second coil being connected to the first node;

a receiver with at least one input connected to a node of the second tank circuit;

a battery;

a rectifier between the battery and the first tank circuit; and

medical circuitry electrically coupled to the battery.

22. The medical system of claim 21, wherein the first coil portion and the second coil portion are coil portions of a single coil having a tap that establishes the first node.

23. The medical system of claim 21, wherein the first coil portion and the second coil portion are geometrically oriented so that current of the first tank circuit sums with current of the second tank circuit at the first node.

24. The medical system of claim 21, wherein the receiver is connected across the second coil portion.

25. The medical system of claim 21, further comprising a switch between one side of the rectifier and ground, and a device controller setting the switch to an open state to provide full wave rectification and setting the switch to a closed state to provide half wave rectification.

26. The medical system of claim 21, further comprising a tank switch that is connected across the second tank circuit, and a device controller that comprises logic that closes the tank switch when receiving telemetry signals.

27. The medical system of claim 26, wherein a first input of the receiver is connected to a node of the tank switch.

28. The medical system of claim 27, wherein a second input of the receiver is connected to a node of the second tank circuit that is opposite the node of the tank switch.

29. The medical system of claim 21, further comprising a circuit pathway including a switch in series with a resistor, the circuit pathway being in parallel with the first coil portion of the first tank circuit.

30. The medical system of claim 29, further comprising a device controller that comprises logic to detect an overcharge condition, to set the switch of the circuit pathway to a first state while an overcharge condition is undetected, and to set the switch of the circuit pathway to a second state upon detecting the overcharge condition.

31. A method of providing telemetry and recharging for an implantable medical device, comprising:

receiving energy at a first frequency via a first tank circuit of an implantable medical device that is tuned to the first frequency by a first coil portion and a first capacitance, the first coil being connected to a first node;

receiving energy at a second frequency via a second tank circuit of the implantable medical device that is tuned to the second frequency by a second coil portion and a second capacitance, the second coil portion being connected to the first node;

obtaining the energy from the second tank circuit at a receiver of the implantable medical device with at least one input connected to a node of the second tank circuit;

passing the energy from the first tank circuit through a rectifier of the implantable medical device to a battery of the implantable medical device; and

providing energy from the battery to medical circuitry of the implantable medical device.

32. The method of claim 31, wherein the first coil portion and the second coil portion are coil portions of a single coil having a tap that establishes the first node.

33. The method of claim 31, wherein the first coil portion and the second coil portion are geometrically oriented so that current of the first tank circuit sums with current of the second tank circuit at the first node.

34. The method of claim 31, wherein the receiver is connected across the second coil portion.

35. The method of claim 31, wherein the implantable medical device has a switch between one side of the rectifier and ground, and the method further comprising setting the switch to an open state to provide full wave rectification and setting the switch to a closed state to provide half wave rectification.

36. The method of claim 31, wherein the implantable medical device has a tank switch that is connected across the second tank circuit, the method further comprising closing the tank switch when receiving telemetry signals.

37. The method of claim 36, wherein a first input of the receiver is connected to a node of the tank switch.

38. The method of claim 37, wherein a second input of the receiver is connected to a node of the second tank circuit that is opposite the node of the tank switch.

39. The method of claim 31, wherein the implantable medical device includes a circuit pathway including a switch in series with a resistor, the circuit pathway being in parallel with the first coil portion of the first tank circuit.

40. The method of claim 39, further comprising detecting whether an overcharge condition is occurring, setting the switch of the circuit pathway to a first state while an overcharge condition is undetected, and setting the switch of the circuit pathway to a second state upon detecting the overcharge condition.