Granted Patent B2

US 8,868,203 · App. 11/925,749 · Granted Oct 21, 2014

Abstract

Claims (36)

1. A method comprising:

providing a therapeutic electrical signal to a lead assembly of an implantable medical device;

receiving return signals in response to the therapeutic electrical signal, each return signal comprising a voltage signal associated with the lead assembly for a pulse of the therapeutic electrical signal;

determining, based on the return signals, whether a voltage level of a charge device of the implantable medical device is sufficient to generate a controlled-current level of the therapeutic electrical signal;

comparing the return signals to a threshold range;

asserting a feedback signal for each return signal outside the threshold range; and

determining that a lead condition problem exists when the feedback signal is asserted and the voltage level of the charge device is sufficient to generate the controlled-current level of the therapeutic electrical signal.

2. The method of claim 1 , wherein the feedback signal includes a voltage low signal when the return signal associated with a particular pulse is below the threshold range and wherein the feedback signal includes a voltage high signal when the return signal for the particular pulse is above the threshold range.

3. The method of claim 1 , further comprising determining that the lead condition problem indicates a lead break when the feedback signal indicates an impedance associated with the lead assembly is above a threshold.

4. The method of claim 1 , further comprising determining that the lead condition problem indicates a lead short when the feedback signal indicates an impedance associated with the lead assembly is below a threshold.

5. The method of claim 1 , wherein the threshold range comprises a first range above a predicted lead voltage and a second range below the predicted lead voltage, wherein the predicted lead voltage is based on a desired lead impedance and the controlled-current level of the therapeutic electrical signal.

6. The method of claim 1 , further comprising performing assessments of lead health prior to delivery of subsequent therapeutic electrical signals after determining that the lead condition problem exists.

7. The method of claim 1 , further comprising storing data related to the feedback signal, wherein the data includes a time stamp associated with the feedback signal.

8. The method of claim 1 , further comprising acquiring patient activity data; and in response to the feedback signal being asserted at a particular time, storing data related to the feedback signal and the patient activity data associated with the particular time.

9. The method of claim 8 , further comprising comparing the patient activity data and the data related to the feedback signal at the particular time with corresponding patient activity data and feedback signal data associated with a second particular time when the feedback signal was asserted; and identifying one or more activities common to the particular time and the second particular time.

10. A method comprising:

providing a pulsed therapeutic electrical signal to a lead assembly of an implantable medical device;

measuring a voltage across leads of the lead assembly responsive to each pulse of the pulsed therapeutic electrical signal;

determining, based on the voltage across the leads of the lead assembly responsive to a particular pulse, whether a voltage level of a charge device of the implantable medical device is sufficient to generate a controlled-current level of the pulsed therapeutic electrical signal;

asserting a feedback signal when the voltage corresponding to the particular pulse of the pulsed therapeutic electrical signal is outside a threshold range; and

determining that a lead condition problem exists when the feedback signal is asserted and the voltage level of the charge device is sufficient to generate the controlled-current level of the pulsed therapeutic electrical signal.

11. The method of claim 10 , further comprising storing data associated with the feedback signal.

12. The method of claim 10 , further comprising determining that the lead condition problem indicates a lead short when the feedback signal indicates an impedance above a threshold.

13. The method of claim 10 , wherein the threshold range comprises a first range above a predicted lead voltage and a second range below the predicted lead voltage, wherein the predicted lead voltage is based on a desired lead impedance and the controlled-current level of the pulsed therapeutic electrical signal.

14. The method of claim 10 , wherein the feedback signal is a voltage low signal when the voltage corresponding to the particular pulse is below the threshold range and wherein the feedback signal is a voltage high signal when the voltage corresponding to the particular pulse is above the threshold range.

15. The method of claim 10 , further comprising acquiring physiological data; and in response to the feedback signal being asserted at a particular time, storing data related to the feedback signal and the physiological data associated with the particular time.

16. The method of claim 15 , further comprising comparing the data related to the feedback signal and the physiological data at the particular time with corresponding physiological data and feedback data associated with a second particular time when the feedback signal was asserted; and identifying one or more physiological conditions common between the particular time and the second particular time.

17. A non-transitory computer-readable medium comprising instructions executable by a processor to:

cause a pulsed therapeutic electrical signal to be applied to a lead assembly of an implantable medical device;

determine, based on a measured voltage across leads of the lead assembly responsive to a particular pulse of the pulsed therapeutic electrical signal, whether a voltage level of a charge device of the implantable medical device is sufficient to generate a controlled-current level of the pulsed therapeutic electrical signal;

assert a feedback signal when the measured voltage corresponding to the particular pulse of the pulsed therapeutic electrical signal is outside a threshold range; and

determine that a lead condition problem exists when the feedback signal is asserted and the voltage level of the charge device is sufficient to generate the controlled-current level of the pulsed therapeutic electrical signal.

18. The non-transitory computer-readable medium of claim 17 , wherein the feedback signal is a voltage low signal when the measured voltage corresponding to the particular pulse is below the threshold range and wherein the feedback signal is a voltage high signal when the measured voltage corresponding to the particular pulse is above the threshold range.

19. The non-transitory computer-readable medium of claim 17 , wherein the threshold range comprises a first range above a predicted lead voltage and a second range below the predicted lead voltage, wherein the predicted lead voltage is based on a desired lead impedance and the controlled-current level of the pulsed therapeutic electrical signal.

20. The non-transitory computer-readable medium of claim 17 , further comprising instructions executable by the processor to determine that the lead condition problem indicates a lead break when the feedback signal indicates an impedance associated with the lead assembly is above a threshold.

21. The non-transitory computer-readable medium of claim 17 , further comprising instructions executable by the processor to determine that the lead condition problem indicates a lead short when the feedback signal indicates an impedance associated with lead assembly is below a threshold.

Assignments (6)