ELECTRICAL STIMULATOR WITH VOLTAGE MODE EMULATION USING REGULATED CURRENT

• US 20110264171A1
• Filed: 04/27/2010
• Published: 10/27/2011
• Est. Priority Date: 04/27/2010
• Status: Active Grant

• Current Assignee: Medtronic Incorporated (Medtronic Plc)
• Original Assignee: Medtronic Incorporated (Medtronic Plc)
• Inventors: Torgerson, Nathan A.
• Granted Patent: US 9,020,589 B2
• Time in Patent Office: Days
• US Class Current: 607/59
• CPC Class Codes: A61N 1/36 for stimulation
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters

Abstract

Techniques are described for generating electrical stimulation current pulses for delivery of electrical stimulation therapy via a current-controlled system that emulates voltage pulses generated via a voltage-controlled system. In one example, a method includes receiving user input specifying a voltage level of electrical stimulation to be delivered by one or more of a plurality of electrodes implanted within the patient, selectively coupling the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient, selectively coupling at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient, determining a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths, and delivering the determined regulated currents via the respective regulated current paths.

Claims

1. A method for delivering electrical stimulation therapy, the method comprising:

receiving user input specifying a voltage level of electrical stimulation to be delivered by one or more of a plurality of electrodes implanted within the patient;

selectively coupling the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient;

selectively coupling at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient;

determining a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths; and

delivering the determined regulated currents via the respective regulated current paths.

2. The method of claim 1,

wherein selectively coupling the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient comprises:

coupling a first electrode to a first regulated current path to deliver a first amount of the electrical stimulation current; and

coupling a second electrode to a second regulated current path to deliver a second amount of the electrical stimulation current, and

wherein selectively coupling at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient comprises;

coupling a third electrode to the unregulated current path to deliver a third amount of the electrical stimulation current approximately equal to a sum of the first and second amounts of the electrical stimulation current, wherein the unregulated current path is coupled to a reference voltage.

3. The method of claim 1, wherein at least some of the plurality of electrodes are carried by one or more leads implanted within the patient.

4. The method of claim 1, further comprising coupling the electrodes to the regulated and unregulated current paths on a selective basis to form different electrode configurations.

5. The method of claim 1, wherein determining a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths comprises:

delivering a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

measuring a voltage difference value between the first electrode and one of the plurality of electrodes coupled to the unregulated current path;

calculating an impedance value between the first electrode and the one of the plurality of electrodes coupled to an unregulated current path based on the first electrical current and the measured voltage difference value; and

determining the regulated current based on the calculated impedance value.

6. The method of claim 1, wherein determining a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths comprises:

delivering a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

measuring a voltage at the first electrode; and

adjusting the first electrical current in response to the measured voltage.

7. The method of claim 1, wherein delivering the determined regulated currents via the respective regulated current paths comprises:

generating one of the determined regulated currents via a respective current regulator, the one of the determined regulated currents the having a pulse current level, a pulse voltage level, and a pulse width;

controlling the pulse current level to decrease during the pulse width; and

delivering the one of the determined regulated currents pulse via one or more implantable electrodes.

8. The method of claim 7, wherein generating one of the determined regulated currents via a respective current regulator comprises generating one of the determined regulated currents having first and second sub-pulses, the second sub-pulse following the first sub-pulse in time, wherein the pulse current level of the second sub-pulse is less than the pulse current level of the first sub-pulse.

9. A system for delivering electrical stimulation therapy, the device comprising:

a plurality of implantable electrodes;

a user interface configured to receive user input from a user specifying a voltage level of electrical stimulation to be delivered by one or more of the plurality of electrodes;

a stimulation controller configured to;

selectively couple the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient;

selectively couple at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient; and

a processor configured to;

determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths; and

control delivery of the determined regulated currents via the respective regulated current paths.

10. The system of claim 9,

wherein the stimulation controller configured to selectively couple the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient is further configured to:

couple a first electrode to a first regulated current path to deliver a first amount of the electrical stimulation current; and

couple a second electrode to a second regulated current path to deliver a second amount of the electrical stimulation current, and

wherein the stimulation controller configured to selectively couple at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient is further configured to;

couple a third electrode to the unregulated current path to deliver a third amount of the electrical stimulation current approximately equal to a sum of the first and second amounts of the electrical stimulation current, wherein the unregulated current path is coupled to a reference voltage.

11. The system of claim 9, wherein at least some of the plurality of electrodes are carried by one or more leads implanted within the patient.

12. The system of claim 9, wherein the stimulation controller is further configured to couple the electrodes to the regulated and unregulated current paths on a selective basis to form different electrode configurations.

13. The system of claim 9, wherein the processor configured to determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths is further configured to:

control delivery of a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

control measurement of a voltage difference value between the first electrode and one of the plurality of electrodes coupled to the unregulated current path;

calculate an impedance value between the first electrode and the one of the plurality of electrodes coupled to an unregulated current path based on the first electrical current and the measured voltage difference value; and

determine the regulated current based on the calculated impedance value.

14. The system of claim 9, wherein the processor configured to determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths is further configured to:

control delivery of a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

control measurement of a voltage at the first electrode; and

control adjustment of the first electrical current in response to the measured voltage.

15. The system of claim 9, wherein the processor configured to control delivery of the determined regulated currents via the respective regulated current paths is further configured to:

control generation of one of the determined regulated currents via a respective current regulator, the one of the determined regulated currents the having a pulse current level, a pulse voltage level, and a pulse width;

control the pulse current level to decrease during the pulse width; and

control delivery of the one of the determined regulated currents pulse via one or more implantable electrodes.

16. The system of claim 15, wherein the processor configured to control generation of one of the determined regulated currents via a respective current regulator is further configured to control generation of one of the determined regulated currents having first and second sub-pulses, the second sub-pulse following the first sub-pulse in time, wherein the pulse current level of the second sub-pulse is less than the pulse current level of the first sub-pulse.

17. A computer-readable storage medium comprising instructions that, when executed by a processor, cause the processor to:

receive user input specifying a voltage level of electrical stimulation to be delivered by one or more of a plurality of electrodes implanted within the patient;

selectively couple the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient;

selectively couple at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient;

determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths; and

control delivery of the determined regulated currents via the respective regulated current paths.

18. The computer-readable storage medium of claim 17,

wherein the instructions that selectively couple the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient comprise further instructions that, when executed by a processor, cause the processor to:

coupling a first electrode to a first regulated current path to deliver a first amount of the electrical stimulation current; and

coupling a second electrode to a second regulated current path to deliver a second amount of the electrical stimulation current, and

wherein the instructions that selectively couple at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient comprise further instructions that, when executed by a processor, cause the processor to;

couple a third electrode to the unregulated current path to deliver a third amount of the electrical stimulation current approximately equal to a sum of the first and second amounts of the electrical stimulation current, wherein the unregulated current path is coupled to a reference voltage.

19. The computer-readable storage medium of claim 17, wherein at least some of the plurality of electrodes are carried by one or more leads implanted within the patient.

20. The computer-readable storage medium of claim 17, further comprising instructions that, when executed by a processor, cause the processor to couple the electrodes to the regulated and unregulated current paths on a selective basis to form different electrode configurations.

21. The computer-readable storage medium of claim 17, wherein the instructions that cause the processor to determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths comprise further instructions that, when executed by a processor, cause the processor to:

control delivery of a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

control measurement of a voltage difference value between the first electrode and one of the plurality of electrodes coupled to the unregulated current path;

calculate an impedance value between the first electrode and the one of the plurality of electrodes coupled to an unregulated current path based on the first electrical current and the measured voltage difference value; and

determine the regulated current based on the calculated impedance value.

22. The computer-readable storage medium of claim 17, wherein the instructions that, when executed by a processor, cause the processor to determine a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths comprise further instructions that, when executed by a processor, cause the processor to:

control delivery of a first electrical current via a first electrode of the one or more electrodes selectively coupled to the respective regulated current paths;

control measurement of a voltage at the first electrode; and

adjust the first electrical current in response to the measured voltage.

23. The computer-readable storage medium of claim 17, wherein the instructions that, when executed by a processor, cause the processor to control delivery of the determined regulated currents via the respective regulated current paths comprise further instructions that, when executed by a processor, cause the processor to:

control generation of one of the determined regulated currents via a respective current regulator, the one of the determined regulated currents the having a pulse current level, a pulse voltage level, and a pulse width;

control the pulse current level to decrease during the pulse width; and

control delivery of the one of the determined regulated currents pulse via one or more implantable electrodes.

24. The computer-readable storage medium of claim 23, wherein the instructions that, when executed by a processor, cause the processor to control generation of one of the determined regulated currents via a respective current regulator comprise further instructions that, when executed by a processor, cause the processor to:

control generation of one of the determined regulated currents having first and second sub-pulses, the second sub-pulse following the first sub-pulse in time, wherein the pulse current level of the second sub-pulse is less than the pulse current level of the first sub-pulse.

25. A device for delivering electrical stimulation therapy, the device comprising:

means for receiving user input specifying a voltage level of electrical stimulation to be delivered by one or more of a plurality of electrodes implanted within the patient;

means for selectively coupling the one or more electrodes to respective regulated current paths to deliver the electrical stimulation to the patient;

means for selectively coupling at least another of the plurality of electrodes implanted within the patient to an unregulated current path to deliver the electrical stimulation to the patient;

means for determining a regulated current for each respective regulated current path in order to produce the specified voltage level at the one or more electrodes selectively coupled to the respective regulated current paths; and

means for delivering the determined regulated currents via the respective regulated current paths.