Heuristic safety net for transitioning configurations in a neural stimulation system

• US 8,868,198 B2
• Filed: 03/22/2013
• Issued: 10/21/2014
• Est. Priority Date: 03/23/2012
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Lee, Dongchul, Zhu, Changfang
• Primary Examiner(s): Layno, Carl H
• Assistant Examiner(s): PIATESKI, ERIN M
• Application Number:
  US13/849,375
• Publication Number:
  US 20130253610A1
• Time in Patent Office: 578 Days
• Field of Search: 607/59
• US Class Current: 607/59
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36142 for improving safety
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/37211 Means for communicating with stimulators
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: A61N 1/37264 Changing the program; Upgrading firmware

Abstract

A system and method using a plurality of electrodes. An immediate virtual multipole is defined, an immediate electrode configuration emulating the immediate virtual multipole is defined, electrical energy is conveyed to the electrodes in accordance with the immediate electrode configuration, a new virtual multipole is defined by changing a parameter of the immediate virtual multipole by a step size, a new electrode configuration that emulates the new virtual multipole is defined, a difference value as a function of the immediate virtual multipole and the new virtual multipole is computed, the different value is compared to a limit value, electrical energy is conveyed to the electrodes in accordance with the new electrode configuration if the difference value does not exceed the limit value, and the absolute value of the step size is decreased to create a new step size if the difference value does exceed the limit value.

Claims

1. A system for an electrical neurostimulator coupled to a plurality of electrodes, comprising:

telemetry circuitry configured for communicating with the electrical neurostimulator; and

a controller/processor configured for (a) defining an immediate virtual multipole, (b) defining an immediate electrode configuration that emulates the immediate virtual multipole, (c) instructing the electrical neurostimulator via the telemetry circuitry to convey electrical energy to the plurality of electrodes in accordance with the immediate electrode configuration, (d) defining a new virtual multipole by changing a parameter of the immediate virtual multipole by a step size, (e) defining a new electrode configuration that emulates the new virtual multipole, (f) computing a difference value as a function of the immediate virtual multipole and the new virtual multipole, after the new electrode configuration has been defined, (g) comparing the difference value to a limit value, (h) instructing the electrical neurostimulator to convey electrical energy to the plurality of electrodes in accordance with the new electrode configuration if the difference value does not exceed the limit value, and (i) decreasing the absolute value of the step size to create a new step size, and repeating steps (d)-(i) for the new step size if the difference value exceeds the limit value.

2. The system of claim 1, wherein the controller/processor is configured for (j) not instructing the electrical neurostimulation to convey electrical energy to the plurality of electrodes if the difference value exceeds the limit value.

3. The system of claim 1, wherein the controller/processor is configured for (d) defining the new virtual multipole by changing at least one other parameter of the immediate virtual multipole by another step size, and (i) decreasing the absolute value of the other step size to create another new step size, and repeating steps (d)-(i) for the new step size and the other new step size if the difference value exceeds the limit value.

4. The system of claim 1, wherein the parameter comprises one of a location, focus, and upper anode percentage of the immediate virtual multipole.

5. The system of claim 1, wherein the step size is one of a positive value and a negative value.

6. The system of claim 1, wherein the controller/processor is configured for (f) computing another difference value as another function of the immediate virtual multipole and the new virtual multipole, (g) comparing the other difference value to another limit value, (h) instructing the electrical neurostimulator to convey the electrical energy to the plurality of electrodes in accordance with the new set of stimulation parameters if neither the difference value exceeds the limit value nor the other difference value exceeds the other limit value, and (i) decreasing the absolute value of the step size to create the new step size and repeating steps (d)-(i) for the new step size if either the difference value exceeds the limit value or the other difference value exceeds the other limit value.

7. The system of claim 1, wherein the difference value is a function of the immediate electrode configuration and the new electrode configuration.

8. The system of claim 7, wherein the difference value comprises one of a change in a cathodic current on an individual one of the electrodes, a change in an anodic current on an individual one of the electrodes, a total change in cathodic current on the electrodes, and a total change in anodic current on the electrodes.

9. The system of claim 1, wherein the difference value is a function of one of an electrical field, absolute potential, current density, an activating function, and a total net driving function that is derived from the immediate virtual multipole and the new virtual multipole.

10. The system of claim 1, wherein the difference value is a displacement between one pole of the immediate virtual multipole and a corresponding pole of the new virtual multipole.

11. The system of claim 1, further comprising a user interface configured for receiving a user input, wherein the controller/processor is configured for defining the new virtual multipole in response to the user input.

12. The system of claim 1, wherein the current and new electrode configurations are respectively current and new fractionalized combinations.

13. The system of claim 1, further comprising a housing containing the telemetry circuitry and the controller/processor.

14. A method of providing therapy to a patient using a plurality of electrodes, comprising:

(a) defining an immediate virtual multipole;

(b) defining an immediate electrode configuration that emulates the immediate virtual multipole;

(c) conveying electrical energy to the plurality of electrodes in accordance with the immediate electrode configuration;

(d) defining a new virtual multipole by changing a parameter of the immediate virtual multipole by a step size;

(e) defining a new electrode configuration that emulates the new virtual multipole;

(f) computing a difference value as a function of the immediate virtual multipole and the new virtual multipole;

(g) comparing the difference value to a limit value;

(h) conveying electrical energy to the plurality of electrodes in accordance with the new electrode configuration if the difference value does not exceed the limit value; and

(i) decreasing the absolute value of the step size to create a new step size, and repeating steps (d)-(i) for the new step size if the difference value exceeds the limit value.

15. The method of claim 14, further comprising (j) not instructing the electrical neurostimulator to convey electrical energy to the plurality of electrodes if the difference value exceeds the limit value.

16. The method of claim 14, wherein:

(d) the new virtual multipole is defined by changing another parameter of the immediate virtual multipole by another step size; and

(i) the absolute value of the other step size is decreased to create another new step size, and steps (d)-(i) are repeated for the new step size and the other new step size if the difference value exceeds the limit value.

17. The method of claim 14, wherein the parameter comprises one of a location, focus, and upper anode percentage of the immediate virtual multipole.

18. The method of claim 14, wherein the step size is one of a positive value and a negative value.

19. The method of claim 14, wherein:

(f) another difference value is computed as another function of the immediate virtual multipole and the new virtual multipole;

(g) the other difference value is compared to another limit value;

(h) the electrical energy is conveyed to the plurality of electrodes in accordance with the new set of stimulation parameters if neither the difference value exceeds the limit value nor the other difference value exceeds the other limit value; and

(i) the absolute value of the step size is decreased to create the new step size and steps (d)-(i) are repeated for the new step size if either the difference value exceeds the limit value or the other difference value exceeds the other limit value.

20. The method of claim 14, wherein the difference value is a function of the immediate electrode configuration and the new electrode configuration.

21. The method of claim 20, wherein the difference value comprises one of a change in a cathodic current on an individual one of the electrodes, a change in an anodic current on an individual one of the electrodes, a total change in cathodic current on the electrodes, and a total change in anodic current on the electrodes.

22. The method of claim 14, wherein the difference value is a function of one of an electrical field, absolute potential, current density, an activating function, and a total net driving function that is derived from the immediate virtual multipole and the new virtual multipole.

23. The method of claim 14, wherein the difference value is a displacement between one pole of the immediate virtual multipole and a corresponding pole of the new virtual multipole.

24. The method of claim 14, wherein the new virtual multipole is defined in response to a user input.

25. The method of claim 14, wherein the current and new electrode configurations are respectively current and new fractionalized combinations.