Battery Management for an Implantable Medical Device

• US 20160287886A1
• Filed: 06/14/2016
• Published: 10/06/2016
• Est. Priority Date: 07/20/2011
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Parramon, Jordi, Marnfeldt, Goran N., Ozawa, Robert, Feldman, Emanuel, Peterson, Dave, He, Yuping
• Granted Patent: US 9,855,438 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61N 1/3787 from an external energy source

Abstract

Battery management circuitry for an implantable medical device such as an implantable neurostimulator is described. The circuitry has a T-shape with respect to the battery terminal, with charging circuitry coupled between rectifier circuitry and the battery terminal on one side of the T, and load isolation circuitry coupled between the load and the battery terminal on the other side. The load isolation circuitry can comprise two switches wired in parallel. An undervoltage fault condition opens both switches to isolate the battery terminal from the load to prevent further dissipation of the battery. Other fault conditions will open only one the switches leaving the other closed to allow for reduced power to the load to continue implant operations albeit at safer low-power levels. The battery management circuitry can be fixed in a particular location on an integrated circuit which also includes for example the stimulation circuitry for the electrodes.

Claims

1. Circuitry for an implantable medical device, comprising:

charging circuitry for providing power to a battery terminal node; and

isolation circuitry comprising first and second load switches coupled in parallel between the battery terminal node and the load.

2. The circuitry of claim 1, wherein the first load switch has a first resistance, and the second load switch has a second resistance smaller than the first resistance.

3. The circuitry of claim 1,

wherein the first load switch is opened if the voltage at the battery terminal node falls below a threshold, and

wherein the second load switch is opened if either the voltage at the battery terminal node falls below a threshold or if at least one other fault condition is asserted.

4. The circuitry of claim 3, wherein the first load switch has a first resistance, and the second load switch has a second resistance smaller than the first resistance.

5. The circuitry of claim 3, wherein the fault condition comprises an overcurrent between the battery terminal node and the load.

6. The circuitry of claim 3, wherein the fault conditions comprise an overcurrent between the battery terminal node and the load and an emergency shutdown condition.

7. The circuitry of claim 6, wherein the emergency shutdown condition comprises a magnetic field generated external to the implantable medical device.

8. Circuitry useable in an implantable medical device comprising:

an integrated circuit, comprising;

stimulation circuitry for stimulating a plurality of electrodes coupleable to integrated circuit outputs of the integrated circuit;

a battery input/output of the integrated circuit coupleable to a terminal of a battery;

battery management circuitry for (i) receiving an input voltage for charging the battery via the battery input/output, and (ii) producing a power supply voltage from the battery; and

a load powered by the power supply voltage, wherein the load comprises the stimulation circuitry.

9. The circuitry of claim 8, wherein the load further comprises other circuitry on the integrated circuit.

10. The circuitry of claim 9, wherein the load further comprises circuitry coupleable to a load output of the integrated circuit.

11. The circuitry of claim 10, wherein the circuitry coupleable to the load output comprises a microcontroller.

12. The circuitry of claim 8, wherein the input voltage is supplied to an input of the integrated circuit and is used for passively charging the battery or for producing power to charge the battery.

13. The circuitry of claim 12, wherein the input is coupleable to rectifier circuitry for producing the input voltage.

14. The circuitry of claim 8, wherein the battery management circuitry is isolated from other circuitry on the integrated circuit.

15. The circuitry of claim 14, wherein the battery management circuitry is isolated by a ring of insulation around the battery management circuitry.

16. The circuitry of claim 8, wherein the integrated circuit further comprises bus inputs/outputs coupleable to a bus outside of the integrated circuit.

17. The circuitry of claim 16, wherein the bus inputs/outputs couple to a source controller of the integrated circuit for providing at least one control signal to a power source in the battery management circuitry for producing the power for charging the battery.

18. The circuitry of claim 17, wherein the at least one control signal is AC coupled to the power source.