SYSTEMS AND METHODS FOR DETECTING FAULTS AND/OR ADJUSTING ELECTRICAL THERAPY BASED ON IMPEDANCE CHANGES

• US 20130116752A1
• Filed: 11/05/2012
• Published: 05/09/2013
• Est. Priority Date: 11/04/2011
• Status: Active Grant

• Current Assignee: Nevro Corporation
• Original Assignee: Nevro Corporation
• Inventors: Parker, Jon, Walker, Andre B., Singh, Udai
• Granted Patent: US 9,814,884 B2
• Time in Patent Office: Days
• US Class Current: 607/62
• CPC Class Codes: A61N 1/3603 Control systems
• CPC Class Codes: A61N 1/36071 Pain
• CPC Class Codes: A61N 1/36142 for improving safety
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration

Abstract

System and methods for detecting impedance changes and for adjusting electrical therapy based on impedance changes are disclosed herein. A method in accordance with a particular embodiment includes applying a therapeutic, paresthesialess electrical signal to a patient via a patient modulation system that includes a signal delivery device in electrical communication with a target neural population of the patient. The method can include monitoring on a periodic basis an impedance of an electrical circuit that includes the signal delivery device. The method can further include detecting a change in the impedance that indicates a fault and providing an indication that the fault exists.

Claims

1. A method for controlling a patient therapy device, comprising:

applying a therapeutic, paresthesia-less electrical signal to a patient via a patient modulation system that includes a signal delivery device in electrical communication with a target neural population of the patient;

automatically monitoring, on a pre-set periodic basis, the impedance of an electrical circuit that includes the signal delivery device; and

detecting a change in impedance in the electrical circuit that indicates a fault.

2. The method of claim 1 wherein detecting the detecting change in impedance includes detecting the change in impedance before the patient senses a change in therapy resulting from the fault.

3. The method of claim 1 wherein the fault includes an open circuit.

4. The method of claim 1, further comprising providing a notification of the fault.

5. The method of claim 4 providing the notification of the fault includes providing the notification of the fault before the patient senses a change in therapy resulting from the fault.

6. The method of claim 4 wherein the notification includes a vibratory signal.

7. The method of claim 4, further comprising directing the notification to a location external to the patient.

8. The method of claim 1, further comprising checking to determine if the fault has been corrected.

9. The method of claim 1, further comprising automatically correcting or compensating for the fault.

10. The method of claim 9 wherein automatically correcting or compensating includes changing active contacts.

11. The method of claim 9 wherein automatically correcting or compensating includes changing a number of active contacts.

12. The method of claim 9 wherein automatically correcting or compensating includes automatically correcting or compensating before the patient senses a change in therapy resulting from the fault.

13. The method of claim 9, further comprising gradually increasing a strength of the signal in response to the fault being corrected.

14. The method of claim 1, further comprising adjusting a compliance voltage in response to detecting the fault.

15. The method of claim 1 wherein applying the therapeutic, paresthesia-less electrical signal includes applying the signal at a frequency in a range of from about 1.5 kHz to about 100 kHz.

16. A method for controlling a patient therapy device, comprising:

applying a therapeutic, paresthesia-less electrical signal to a patient via a patient modulation system that includes a signal delivery device in electrical communication with a target neural population of the patient, wherein the therapeutic electrical signal has a frequency in the range of from about 1.5 kHz to about 100 kHz;

automatically monitoring, on a pre-set periodic basis, the impedance of an electrical circuit that includes the signal delivery device;

detecting a change in impedance in the electrical circuit that indicates a fault;

automatically correcting the fault before the patient senses a change in therapy resulting from the fault; and

automatically providing a notification of the fault.

17. A patient therapy system, comprising:

a patient-implantable portion that includes a signal generator and a signal delivery device having an electrical contact positioned to be in electrical communication with a target neural population of a patient when implanted;

an impedance detector carried by the implantable portion, the impedance detector being operatively coupled to an electrical circuit that includes the electrode to detect an impedance of the electrical circuit; and

a processor carried by the patient-implantable portion, the processor having a computer-readable medium programmed with instructions that, when executed;

automatically monitor, on a pre-set periodic basis, the impedance of the electrical circuit that includes the signal delivery device; and

receives an indication from the impedance detector corresponding to a fault.

18. The system of claim 17, wherein the processor is configured to automatically correct or compensate for the fault without human intervention, in response to receiving the indication from the impedance detector corresponding to the fault.

19. The system of claim 18 wherein automatically correcting or compensating includes changing a number of active contacts.

20. The method of claim 18 wherein automatically correcting or compensating includes changing active contacts.

21. The system of claim 18, wherein automatically correcting or compensating includes adjusting compliance voltage in response to detecting the fault.

22. The system of claim 18 wherein the processor is configured to:

direct a therapy signal to the electrical contact; and

gradually increase a strength of a therapy signal in response to the fault being corrected.

23. The system of claim 17, wherein the processor is configured to determine if the fault has been corrected.

24. The system of claim 17 wherein the fault includes an open circuit.

25. The system of claim 17, wherein the processor is configured to direct a signal providing notification of the fault.

26. The system of claim 25 wherein the processor is configured to direct a vibratory signal providing notification of the fault.

28. The system of claim 17 wherein the signal generator is configured to direct a paresthesia-less, therapeutic signal at a frequency of from about 1.5 kHz to about 100 kHz.

27. The system of claim wherein 25, wherein the processor is configured to direct a signal providing notification of the fault to a location external to the patient.