APPARATUS AND METHOD FOR DETERMINING THE RELATIVE POSITION AND ORIENTATION OF NEUROSTIMULATION LEADS

• US 20100305631A1
• Filed: 08/16/2010
• Published: 12/02/2010
• Est. Priority Date: 12/04/2001
• Status: Active Grant

• Current Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Neuromodulation Corporation (Boston Scientific Corporation)
• Inventors: Thacker, James R., Bradley, Kerry, Moffitt, Michael A.
• Granted Patent: US 9,192,760 B2
• Time in Patent Office: Days
• US Class Current: 607/2
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/3605 Implantable neurostimulators for stimulating central or peripheral nerve system
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means

Abstract

A method for determining whether the relative position of electrodes used by a neurostimulation system has changed within a patient comprises determining the amplitude of a field potential at each of at least one of the electrodes, determining if a change in each of the determined electric field amplitudes has occurred, and analyzing the change in each of the determined electric field amplitudes to determine whether a change in the relative position of the electrodes has occurred. Another method comprises measuring a first monopolar impedance between a first electrode and a reference electrode, measuring a second monopolar impedance between second electrode and the reference electrode, measuring a bipolar impedance between the first and second electrodes, and estimating an amplitude of a field potential at the second electrode based on the first and second monopolar impedances and the bipolar impedance.

Claims

1. A method of performing a medical procedure using a plurality of electrodes implanted within a patient, comprising:

determining the amplitude of a field potential at each of at least one of the electrodes; and

determining the relative positions of the electrodes based on each of the determined field potential amplitudes.

2. The method of claim 1, wherein the electrodes are carried by a plurality of leads, and wherein the entireties of the leads are implanted within patient, the method further comprising determining the relative positions of the leads based on the determined field potential amplitude of the each of the at least one electrode.

3. The method of claim 1, further comprising:

determining if a change in each of the determined field potential amplitudes has occurred; and

analyzing the change in each of the determined field potential amplitudes to determine whether a change in the relative position of the electrodes has occurred.

4. The method of claim 1, wherein the electrodes are carried by a plurality of leads, wherein the entireties of the leads are implanted within the patient, and wherein the change in each of the determined field amplitudes are analyzed to determine migration of the leads relative to each other.

5. The method of claim 1, further comprising displaying the determined relative positions of the electrodes.

6. The method of claim 1, wherein the at least one electrode comprises a plurality of the electrodes.

7. The method of claim 1, where the field potential amplitude determination comprises directly measuring the field potential amplitude directly at each of the at least one electrode.

8. The method of claim 1, further comprising measuring an electrical impedance at a first one of the electrodes, wherein the determination of the field potential amplitude at each of the at least one electrode comprises estimating each of the field potential amplitudes, at least in part, from the respective measured electrical impedance.

9. The method of claim 8, further comprising:

measuring a first monopolar electrical impedance between the first one of the electrode and a return or reference electrode;

measuring a second monopolar electrical impedance between each of the at least one electrode and the return or reference electrode; and

measuring a molar multipolar electrical impedance between the first one of the electrodes and each of the at least one electrode;

wherein the amplitude of the field potential at each of the at least one electrode is determined based on the measured first monopolar electrical impedance, each of the second monopolar electrical impedances, and each of the measured multipolar electrical impedances.

11. The method of claim 1, further comprising storing each of the determined field potential amplitudes.

12. The method of claim 3, further including initiating corrective action when a determination is made that the relative position of the electrodes has changed.

13. The method of claim 12, wherein the corrective action is initiated automatically.

14. The method of claim 12, wherein the corrective action includes adjusting the amplitude of tissue stimulating electrical energy applied to selected ones of the electrodes.

15. The method of claim 12, wherein the corrective action includes changing selected ones of the electrodes through which tissue stimulating electrical energy is applied.

16. The method of claim 12, wherein the corrective action includes performing a surgical revision on the patient to physically readjust the electrodes.

28. The method of claim 1, further applying conveying tissue stimulating electrical energy to selected ones of the electrodes, thereby providing therapy to the patient.

29. The method of claim 28, further comprising implanting a neurostimulator within the patient, wherein the tissue stimulating electrical energy is conveyed from the neurostimulator to the selected ones of the electrodes.

30. The method of claim 1, wherein the electrodes are implanted within a spinal column of the patient.

10. (canceled)

17. A method for performing a medical procedure using a plurality of electrodes implanted within a patient, comprising:

measuring a first monopolar impedance between a first one of the electrodes and a return or reference electrode;

measuring a second monopolar impedance between a second one of the electrodes and the return or reference electrode;

measuring a multipolar impedance between the first electrode and the second electrode; and

estimating an amplitude of a field potential at the second electrode based on the first and second monopolar impedances and the multipolar impedance.

18. The method of claim 17, wherein the estimated field potential amplitude is approximately equal to the actual field potential at the second electrode when an electrical stimulus is conveyed between the first electrode and the return or reference electrode.

19. The method of claim 17, further comprising determining whether a change in the relative positions of the electrodes has occurred based on the estimated field potential amplitude.

20. The method of claim 19, further comprising performing a function unrelated to the determining whether a change in the relative positions of the electrodes has occurred based on at least one of the first monopolar impedance, second monopolar impedance, and multipolar impedance.

21. The method of claim 20, wherein the function is one or more of determining a remaining battery life of neurostimulator and detecting an electrical short within the neurostimulator.

22. The method of claim 19, further including initiating corrective action when a determination is made that the relative position of the electrodes has changed.

23. The method of claim 19, wherein the corrective action is initiated automatically.

24. The method of claim 19, further comprising displaying the determined relative positions of the electrodes.

25. (canceled)

26. A method for performing a medical procedure using a plurality of electrodes implanted within a patient, comprising:

performing two of the following;

(1) measuring a first monopolar impedance between a first one of the electrodes and a return or reference electrode, and measuring a second monopolar impedance between a second one of the electrodes and the return or reference electrode;

(2) measuring a multipolar impedance between the first electrode and the second electrode; and

(3) measuring a field potential at the second electrode; and

estimating a remaining one of the (1) first and second monopolar impedances;

(2) the multipolar impedance; and

(3) the field potential based on the performance of the two measurements.

27. (canceled)