Electromyographic lead positioning and stimulation titration in a nerve stimulation system for treatment of overactive bladder

• US 9,555,246 B2
• Filed: 08/14/2015
• Issued: 01/31/2017
• Est. Priority Date: 08/15/2014
• Status: Active Grant

• Current Assignee: Axonics, Inc.
• Original Assignee: Axonics Modulation Technologies, Inc.
• Inventors: Jiang, Guangqiang, Woock, John, Schroeder, Dennis, Schmid, Eric
• Primary Examiner(s): Levicky, William
• Application Number:
  US14/827,108
• Publication Number:
  US 20160045747A1
• Time in Patent Office: 536 Days
• US Class Current: 1/1
• CPC Class Codes: A61N 1/0504 Subcutaneous electrodes
• CPC Class Codes: A61N 1/0551 Spinal or peripheral nerve electrodes
• CPC Class Codes: A61N 1/36007 of urogenital or gastrointestinal organs, e.g. for incontinence control
• CPC Class Codes: A61N 1/36017 with leads or electrodes penetrating the skin
• CPC Class Codes: A61N 1/3606 adapted for a particular treatment
• CPC Class Codes: A61N 1/36107 Sexual dysfunction stimulating genital organs A61N1/36007
• CPC Class Codes: A61N 1/36125 Details of circuitry or electric components
• CPC Class Codes: A61N 1/3614 based on impedance measurement
• CPC Class Codes: A61N 1/36146 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36157 Current A61N1/3616 takes precedence
• CPC Class Codes: A61N 1/36185 Selection of the electrode configuration
• CPC Class Codes: A61N 1/37241 providing test stimulations
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means

Abstract

The present invention provides improved methods for positioning of an implantable lead in a patient with an integrated EMG and stimulation clinician programmer. The integrated clinician programmer is coupled to the implantable lead, wherein the implantable lead comprises at least four electrodes, and to at least one EMG sensing electrode minimally invasively positioned on a skin surface or within the patient. The method comprises delivering a test stimulation at a stimulation amplitude level from the integrated clinician programmer to a nerve tissue of the patient with a principal electrode of the implantable lead. Test stimulations are delivered at a same stimulation amplitude level for a same period of time sequentially to each of the four electrodes of the implantable lead. A stimulation-induced EMG motor response is recorded with the integrated clinician programmer for each test stimulation on each electrode of the implantable lead via the at least one pair of EMG sensing electrodes so as to facilitate initial positioning of the implantable lead at a target stimulation region.

Claims

1. A method for improved positioning of an implantable lead in a patient in proximity of a sacral nerve so as to treat a bladder and/or bowel related dysfunction, wherein the implantable lead comprises at least four electrodes electrically coupled to an integrated electromyography (EMG) and stimulation clinician programmer, the method comprising:

performing a sweeping cycle comprising;

delivering a test stimulation at a plurality of stimulation amplitude levels from the integrated clinician programmer to the sacral nerve tissue of the patient with a principal electrode of the implantable lead until a desired stimulation-induced EMG motor response is obtained that corresponds to the principal electrode being positioned in a target stimulation region adjacent the sacral nerve, wherein the principal electrode is selected from the at least four electrodes of the implantable lead;

recording the stimulation amplitude level at which the desired stimulation-induced EMG motor response is obtained with the principal electrode;

delivering test stimulations at a same stimulation amplitude level as the recorded stimulation amplitude level for a same period of time sequentially to each remaining electrode of the at least four electrodes of the implantable lead; and

simultaneously recording with the integrated clinician programmer a first stimulation-induced EMG motor response associated with a big toe of the patient and a second stimulation-induced EMG motor response associated with an anal bellows of the patient for the same level test stimulation on each electrode of the implantable lead during the sweeping cycle so as to facilitate positioning of the implantable lead at the target stimulation region along the sacral nerve; and

performing one or more subsequent sweeping cycles after lateral and/or axial adjustment of a position of the implantable lead based on the first and second stimulation-induced EMG motor responses simultaneously recorded during the last performed sweeping cycle until stimulation-induced EMG motor response recordings are indicative of multiple electrodes of the at least four electrodes being in the target region along the sacral nerve.

2. The method of claim 1, further comprising receiving user input related to adjustment of the stimulation amplitude level of the test stimulation for the principal electrode in proportional increments to achieve a desired stimulation-induced EMG motor response via a graphical user interface of the integrated clinician programmer.

3. The method of claim 1, further comprising automatically adjusting the stimulation amplitude level of the test stimulation for the principal electrode in proportional increments until a desired stimulation-induced EMG motor response is detected.

4. The method of claim 1, further comprising calculating an EMG response value for each test stimulation delivered at a given stimulation amplitude level to each electrode based on a maximum EMG response amplitude associated with each electrode which is normalized relative to an EMG response amplitude associated with the principal electrode, wherein the EMG response value associated with each electrode provides visual feedback to a user on how to laterally or axially position the implantable lead at the target stimulation region via a graphical user interface of the integrated clinician programmer.

5. The method of claim 1, further comprising receiving user input related to an adjustment of a stimulation amplitude threshold of the test stimulation for each electrode in proportional increments to achieve a desired stimulation-induced EMG motor response at a minimum stimulation amplitude threshold via a graphical user interface of the integrated clinician programmer.

6. The method of claim 5, further comprising receiving user input related to the first or second recorded stimulation-induced EMG motor response or a sensory response from the patient associated with the stimulation amplitude threshold for each electrode.

7. The method of claim 1, further comprising automatically adjusting a stimulation amplitude threshold of the test stimulation for each electrode in proportional increments to achieve a desired stimulation-induced EMG motor response at a minimum stimulation amplitude threshold.

8. The method of claim 7, further comprising:

displaying visual feedback to a user on the stimulation amplitude threshold for each electrode via a graphical user interface of the integrated clinician programmer, wherein the visual feedback comprises color coding from at least three contrasting colors.

9. The method of claim 1, further comprising automatically storing or displaying data for each test stimulation delivered at incremental or proportional stimulation amplitude levels for each individual electrode of at least four electrodes of the implantable lead and the associated EMG recording of the big toe and the anal bellows of the patient for each test stimulation.

10. The method of claim 1, further comprising delivering the test stimulation to the sacral nerve tissue via a foramen needle and recording the stimulation-induced EMG motor response for each test stimulation delivered to the foramen needle so as to provide for initial positioning of the implantable lead at a target stimulation region.

11. The method of claim 10, further comprising receiving user input related to an adjustment of a stimulation amplitude level of the test stimulation for the foramen needle in proportional increments to achieve a desired stimulation-induced EMG motor response via a graphical user interface of the integrated clinician programmer.

12. The method of claim 10, further comprising automatically adjusting a stimulation amplitude level of the test stimulation for the foramen needle in proportional increments until a desired stimulation-induced EMG motor response is detected.

13. The method of claim 1, further comprising automatically selecting the principal electrode.

14. The method of claim 1, further comprising receiving user input related to selection of the principal electrode via a graphical user interface of the integrated clinician programmer.

15. The method of claim 1, further comprising automatically adjusting the stimulation amplitude level of the test stimulation for the principal electrode until a desired stimulation-induced EMG motor response is detected.

16. The method of claim 15, wherein automatically adjusting comprises increasing the stimulation amplitude in increments of 0.05 mA for a test stimulation less than or equal to 1 mA.

17. The method of claim 15, wherein automatically adjusting comprises increasing the stimulation amplitude in increments of 0.1 mA for a test stimulation more than or equal to 1 mA and less than or equal to 2 mA.

18. The method of claim 15, wherein automatically adjusting comprises increasing the stimulation amplitude in increments of 0.2 mA for a test stimulation more than or equal to 2 mA and less than or equal to 3 mA.

19. The method of claim 15, wherein automatically adjusting comprises increasing the stimulation amplitude in increments of 0.25 mA for a test stimulation more than or equal to 3 mA.

20. The method of claim 1, further comprising receiving user input related to adjustment of the stimulation amplitude level of the test stimulation for the principal electrode in increments in a range from 0.05 mA to 0.25 mA to achieve a desired stimulation-induced EMG motor response via a graphical user interface of the integrated clinician programmer.

21. The method of claim 1, wherein the period of time is such that the sweeping cycle of the implantable lead is completed in 5 seconds or less.

22. The method of claim 1, further comprising calculating an EMG response value for each test stimulation delivered at a given stimulation amplitude level to each electrode based on a maximum EMG response amplitude associated with each electrode.

23. The method of claim 22, wherein the maximum EMG response amplitude associated with each electrode is normalized relative to an EMG response amplitude associated with the principal electrode.

24. The method of claim 22, wherein the EMG response value associated with each electrode provides visual feedback to a user on how to laterally or axially position the implantable lead at the target stimulation region via a graphical user interface of the integrated clinician programmer to facilitate placement of the at least four electrodes in the target stimulation region.

25. The method of claim 24, wherein the visual feedback provides directional indication to the user to advance the implantable lead distally along an insertion axis, to retract the implantable lead proximally along the insertion axis, or to steer the implantable lead along a lateral direction from the insertion axis so that a middle of the implantable lead is positioned at the target stimulation region.

26. The method of claim 24, further comprising repeating the delivering test stimulations to each of the four electrodes of the implantable lead and recording steps after lead re-positioning to confirm the calculated EMG response value for each electrode are within a desired value range, or the maximum EMG response amplitude for each electrode are within a desired response range and the associated simulation amplitude for each electrode is within a desired stimulation range.

27. The method of claim 22, further comprising calculating a relative distance or position of each electrode to the target stimulation region based on the EMG response value associated with each electrode.

28. The method of claim 1, wherein the lead is configured to be inserted through a foramen of a sacrum and positioned in proximity of a sacral nerve root so as to treat overactive bladder or bladder related dysfunction.

29. The method of claim 28, wherein the target stimulation region comprises an area between emergence of a sacral nerve from a sacral canal and its convergence with other spinal nerves to form a sciatic nerve.

30. The method of claim 1, further comprising displaying a visual image of the recorded stimulation-induced EMG motor response during each test stimulation on a graphical user interface of the integrated clinician programmer, wherein the visual image includes a waveform comprising a compound muscle action potential (CMAP).

31. The method of claim 1, further repeating the sweeping cycle after lateral and/or axial adjustment of a position of the implantable lead based on the simultaneous recording of the first and second stimulation-induced EMG motor responses during the last previously performed sweeping cycle until at least three electrodes of the at least four electrodes are positioned in the target stimulation region.