Systems and methods for detecting faults and/or adjusting electrical therapy based on impedance changes

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, 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. 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.

1 - 28 . (canceled) 
     
     
         29 . A method for controlling a patient therapy device, comprising:
 applying a therapeutic, paresthesia-less electrical signal to a target neural population in a patient via a patient modulation system that includes a signal delivery device;   monitoring an impedance of an electrical circuit that includes the signal delivery device;   detecting a change in the impedance of the electrical circuit that indicates a fault, before or without the patient sensing a change in therapy resulting from the fault; and   in response to detecting the change in the impedance, automatically correcting or compensating for the fault.   
     
     
         30 . The method of  claim 29  wherein automatically correcting or compensating for the fault is performed before or without the patient perceiving the change in therapy. 
     
     
         31 . The method of  claim 29  wherein automatically correcting or compensating for the fault includes one or more of
 determining if the fault has been corrected, 
 changing an active contact applying the electrical signal to the patient, or 
 changing a number of active contacts used to apply the electrical signal to the patient. 
 
     
     
         32 . The method of  claim 29  wherein automatically correcting or compensating for the fault includes gradually increasing a strength of the electrical signal in response to the fault being corrected. 
     
     
         33 . The method of  claim 29  wherein detecting the change in the impedance occurs while applying the therapeutic, paresthesia-less electrical signal to the patient. 
     
     
         34 . The method of  claim 29  wherein automatically correcting or compensating for the fault includes correcting or compensating for the fault without human intervention. 
     
     
         35 . The method of  claim 29 , further comprising, while applying therapy to the patient, identifying other contacts available to deliver therapy to the patient. 
     
     
         36 . The method of  claim 29  wherein applying the therapeutic, paresthesia-less electrical signal includes applying the electrical signal at a frequency in a range from 1.5 kHz to 100 kHz. 
     
     
         37 . The method of  claim 29  wherein monitoring the impedance includes monitoring the impedance of the electrical circuit on a pre-set periodic basis. 
     
     
         38 . A method for controlling a patient therapy device, comprising:
 applying a therapeutic, paresthesia-less electrical signal to a target neural population in a patient via a patient modulation system that includes an implantable portion having a signal delivery device;   detecting a change in an impedance of the electrical circuit, without the patient sensing a corresponding change in therapy; and   correcting or compensating for the change in impedance without human intervention.   
     
     
         39 . The method of  claim 38  wherein correcting or compensating for the fault is performed before or without the patient perceiving additional pain caused by the corresponding change in therapy. 
     
     
         40 . The method of  claim 38 , further comprising monitoring, on a pre-set periodic basis, the impedance of the electrical circuit. 
     
     
         41 . The method of  claim 38  wherein the electrical signal includes one or more signal delivery parameters, and wherein correcting or compensating for the change in impedance includes updating values of one or more of the signal delivery parameters. 
     
     
         42 . The method of  claim 38  wherein detecting the change in the impedance and correcting or compensating for the change in therapy are each performed by the implantable portion of the patient modulation system. 
     
     
         43 . The method of  claim 38  wherein applying a therapeutic, paresthesia-less electrical signal includes applying a first, paresthesia-less electrical signal to the patient, and wherein correcting or compensating for the change in therapy includes applying a second, paresthesia-less electrical signal to the patient, wherein the second electrical signal is different than the first electrical signal. 
     
     
         44 . 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 neural population in a patient when implanted, wherein the signal generator produces an electrical signal that provides pain relief;   an impedance detector carried by the patient-implantable portion, the impedance detector being operatively coupled to an electrical circuit that includes the electrical contact 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, perform a process that includes
 monitoring the impedance of the electrical circuit; 
 receiving an indication from the impedance detector corresponding to a change in the impedance of the electrical circuit before or without the patient sensing a corresponding change in therapy; and 
 after receiving the indication, automatically correcting or compensating for the change in impedance. 
   
     
     
         45 . The system of  claim 44  wherein the processor is configured to:
 direct the electrical signal to the electrical contact; and 
 gradually increase a strength of the electrical signal in response to the change in impedance being corrected or compensated for. 
 
     
     
         46 . The system of  claim 44  wherein the pain relief lasts at least as long as a duration of the electrical signal that provides the pain relief. 
     
     
         47 . The system of  claim 44  wherein the electrical signal is a paresthesia-less, therapeutic signal at a frequency of from 1.5 kHz to 100 kHz. 
     
     
         48 . The system of  claim 44  wherein the change in impedance results from a fault, and wherein the processor is configured to determine if the fault has been corrected.