Therapy delivery method and system for implantable medical devices

• US 8,532,785 B1
• Filed: 09/26/2012
• Issued: 09/10/2013
• Est. Priority Date: 09/26/2012
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Crutchfield, Randolph E., Boone, Mark R., Cabelka, Lonny V., Rasmussen, Marshall J.
• Primary Examiner(s): Wieland, Robert N
• Application Number:
  US13/626,977
• Time in Patent Office: 349 Days
• Field of Search: 607/59, 607/2, 607/5, 607/9
• US Class Current: 607/59
• CPC Class Codes: A61N 1/3981 High voltage charging circuitry

Abstract

Recent advancements in power electronics technology have provided opportunities for enhancements to circuits of implantable medical devices. The enhancements have contributed to increasing circuit miniaturization and an increased efficiency in the operation of the implantable medical devices. The therapy delivery circuits and techniques of the disclosure facilitate generation of a therapy stimulation waveform that may be shaped based on the patient'"'"'s physiological response to the stimulation waveform. The generated therapy stimulation waveforms include a stepped leading-edge that may be shaped having a varying slope and varying amplitudes associated with each of the segments of the slope. Unlike the truncated exponential waveform delivered by the conventional therapy delivery circuit which is based on the behavior of the output capacitors (i.e., i=C(dV/dt)), the stimulation waveform of the present disclosure may be dynamically shaped as a function of an individual patient'"'"'s response. The dynamically shaped therapy stimulation waveforms facilitate achieving lower capture thresholds which reduces the device'"'"'s supply consumption thereby increasing longevity of the device and facilitate a reduction of tissue damage.

Claims

1. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:

a microprocessor programmed to detect a predetermined event in response to signals received from the electrode;

a controller coupled to the microprocessor, wherein the controller is programmed to generate a control signal in response to detection of the predetermined event; and

a delivery circuit coupled between the controller and the electrode, the delivery circuit including;

a plurality of capacitors;

a coupling circuit connected to the plurality of capacitors and operable to configure a first of the plurality of capacitors for discharge of energy during one or more intervals,

wherein the coupling circuit configures a second of the plurality of capacitors to be serially stacked onto the first capacitor for discharge of energy during a second of the intervals, and

wherein the coupling circuit controls a timing of the stacking of the second capacitor for discharge of energy from the first and second capacitor to generate a stimulation waveform having a stepped leading-edge.

2. The implantable medical system of claim 1, wherein the plurality of capacitors is an integer equal to or greater than two.

3. The implantable medical system of claim 1, wherein the controller is operable to control the duration between the discharge of the first capacitor to the coupling of the second capacitor.

11. The implantable medical system of claim 1, further comprising a delivery bridge coupled between the delivery circuit and the electrode.

12. The implantable medical system of claim 11, wherein the coupling circuit controls the timing and sequence of the coupling of the plurality of capacitors for discharge to the delivery bridge.

13. The implantable medical system of claim 12, wherein the timing and sequence of the coupling is controlled to generate a therapy stimulation waveform having a predetermined slope.

14. The implantable medical system of claim 1, wherein the coupling circuit couples the first capacitor to the other capacitors of the plurality of capacitors in a combination parallel and serial stacking configuration.

16. The implantable medical system of claim 1, wherein the coupling circuit includes:

a control module;

a plurality of stacking circuit modules coupled to the controller, each stacking circuit group including;

a coupling switch coupled to a first polarity terminal of one of the plurality of capacitors; and

a charging switch coupled between the control module and the first polarity terminal.

17. The implantable medical system of claim 16, wherein the number of the plurality of stacking circuit modules corresponds to the number in the plurality of capacitors minus one.

4. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:

a microprocessor programmed to detect a predetermined event in response to signals received from the electrode;

a controller coupled to the microprocessor, wherein the controller is programmed to generate a control signal in response to detection of the predetermined event; and

a delivery circuit coupled between the controller and the electrode, the delivery circuit including;

a plurality of capacitors;

a coupling circuit connected to the plurality of capacitors and operable to configure a first of the plurality of capacitors for discharge of energy during one or more intervals, wherein the coupling circuit comprises;

a control module;

a first switch coupled to a first of the plurality of capacitors and to the controller;

a second switch coupled to a second of the plurality of capacitors and to the controller; and

a third switch coupled between the first and second capacitors and to the controller, wherein the third switch is selectively actuated to stack the first and second capacitors serially.

5. The implantable medical system of claim 4, further comprising a fourth switch controllable by the controller coupled between the third switch and the controller, the third switch being selectively actuated in response to a signal from the fourth switch.

6. The implantable medical system of claim 5, wherein the first and fourth switches are FETs and the second and third switches are triacs.

7. The implantable medical system of claim 5, further comprising:

a third of the plurality of capacitors;

a fifth switch coupled to the third capacitor and the controller, wherein the fifth switch is actuated by the controller.

8. The implantable medical system of claim 7, further comprising a sixth switch coupled between the second and third capacitors and the controller, wherein the sixth switch is selectively actuated to stack the second and the third capacitor in series.

9. The implantable medical system of claim 8, further comprising a seventh switch coupled between the controller and the sixth switch operable to selectively actuate the sixth switch.

10. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:

a microprocessor programmed to detect a predetermined event in response to signals received from the electrode;

a controller coupled to the microprocessor, wherein the controller is programmed to generate a control signal in response to detection of the predetermined event; and

a delivery circuit coupled between the controller and the electrode, the delivery circuit including;

a plurality of capacitors;

a coupling circuit connected to the plurality of capacitors and operable to configure a first of the plurality of capacitors for discharge of energy during one or more intervals, wherein each of the individual remaining plurality of capacitors is coupled in series to the first capacitor with an interval being defined between the coupling of each of the individual remaining plurality of capacitors.

15. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:

a microprocessor programmed to detect a predetermined event in response to signals received from the electrode;

a controller coupled to the microprocessor, wherein the controller is programmed to generate a control signal in response to detection of the predetermined event; and

a delivery circuit coupled between the controller and the electrode, the delivery circuit including;

a plurality of capacitors;

a coupling circuit connected to the plurality of capacitors and operable to configure a first of the plurality of capacitors for discharge of energy during one or more intervals, further comprising a diode coupled between the plurality of capacitors for biasing a direction of flow of charge from the plurality of capacitors.

18. An implantable medical system having electronic circuitry and an electrode coupled to the electronic circuitry, the electronic circuitry comprising:

a delivery bridge coupled to the electrodes;

a plurality of capacitors coupled to the delivery bridge;

a microprocessor programmed to detect a predetermined event in response to signals received from the electrode and to generate a control signal in response to detection of the predetermined event; and

means for dynamically configuring a coupling of the plurality of capacitors to the delivery bridge in response to the control signal issued by the microprocessor, wherein a configuration for the coupling of the plurality of capacitors is selected from multiple coupling configurations, wherein the means for dynamically controlling a coupling of the plurality of capacitors is operable to configure a first of the plurality of capacitors for discharge of energy during one or more intervals, wherein the means for dynamically configuring the coupling of the plurality of capacitors connects a second of the plurality of capacitors in series with the first capacitor after a first of the one or more intervals.

19. The implantable medical system of claim 18, wherein the second capacitor is coupled to the first capacitor upon expiration of a first interval following initiation of discharge of energy stored in the first capacitor.

20. The implantable medical system of claim 18, wherein a stimulation waveform of the energy that is discharged from the capacitors defines a stepped leading edge.

21. The implantable medical system of claim 18, wherein the means for dynamically configuring the coupling of the plurality of capacitors couples a third of the plurality of capacitors to the first and second capacitors in a first of the multiple coupling configurations.

22. The implantable medical system of claim 21, wherein the means for dynamically configuring the coupling of the plurality of capacitors connects each of a remainder of the plurality of capacitors in series with the first, second and third capacitors upon expiration of a predetermined interval.