Apparatus, system, and method for mapping the location of a nerve

• US 9,155,503 B2
• Filed: 10/27/2010
• Issued: 10/13/2015
• Est. Priority Date: 10/27/2010
• Status: Active Grant

• Current Assignee: Cadwell Laboratories, Incorporated (Cadwell Industries Incorporated)
• Original Assignee: Cadwell Laboratories, Incorporated (Cadwell Industries Incorporated)
• Inventors: Cadwell, John
• Primary Examiner(s): Dougherty, Sean
• Assistant Examiner(s): Stout, Michael C
• Application Number:
  US12/913,603
• Publication Number:
  US 20120109004A1
• Time in Patent Office: 1,812 Days
• Field of Search: 600/546, 600/547, 600/587
• US Class Current: 1/1
• CPC Class Codes: A61B 34/10 Computer-aided planning, simulation or modelling of surgical operations
• CPC Class Codes: A61B 5/055 involving electronic [EMR] or nuclear [NMR] magnetic resonance, e.g. magnetic resonance imaging
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 6/5247 combining images from an ionising-radiation diagnostic technique and a non-ionising radiation diagnostic technique, e.g. X-ray and ultrasound
• CPC Class Codes: A61B 8/5261 combining images from different diagnostic modalities, e.g. ultrasound and X-ray

Abstract

An apparatus, system, and method are disclosed for mapping the location of a nerve. The apparatus includes at least one stimulation module, a stimulation detection module, a distance module, and a mapping module. The stimulation module stimulates a nerve with an electrical stimulation current from at least one stimulation electrode. A stimulation detection module detects a muscle reaction resulting from stimulation of the nerve by the at least one stimulation electrode. The distance module uses information from the at least one stimulation electrode and from the stimulation detection module to calculate a distance between the at least one stimulation electrode and the nerve. The mapping module maps a location on the nerve using at least two distances calculated by the distance module and position information of the at least one stimulation electrode for each of the at least two distances calculated.

Claims

1. An apparatus to map the location of a nerve, the apparatus comprising:

a first stimulation electrode configured to stimulate the nerve from a first position, a second stimulation electrode configured to stimulate the nerve from a second position, and a third stimulation electrode configured to stimulate the nerve from a third position, each of the first, second, and third stimulation electrodes remaining stationary during stimulation of the nerve from the first, second, and third positions, and wherein each of the first, second, and third stimulation electrodes is a discrete elongated member configured to penetrate tissue;

a muscle electrode that detects a muscle reaction, the muscle reaction resulting from stimulation of the nerve by the first, second and third stimulation electrodes; and

circuitry configured to;

process information associated with the first, second, and third stimulations and the muscle reaction to calculate a first, second, and third distance corresponding to the distances between the first, second, and third stimulation electrodes and the nerve;

identify a location on the nerve using the first, second, and third distances and position information of the first, second, and third stimulation electrodes for each of the first, second, and third distances; and

map a route of the nerve in three dimensions, wherein the route is determined from the identified location.

2. The apparatus of claim 1, wherein the circuitry is configured to move at least one of the first stimulation electrode, the second stimulation electrode, and the third stimulation electrode to a new position, wherein at each new position of a stimulation electrode, the circuitry is configured to determine one or more additional locations on the nerve.

3. The apparatus of claim 1, further comprising an imaging device that captures an image of a patient'"'"'s anatomy, wherein the circuitry is further configured to overlay the map of the route of the nerve on the image of the patient'"'"'s anatomy captured by the imaging device.

4. The apparatus of claim 3, wherein the circuitry is further configured to mark a position of a marker on at least one of the first, second or third stimulation electrodes, the marker comprising a material detectable by the imaging device, wherein the circuitry is configured to detect the marker to position the map of the route of the nerve on the image of the patient'"'"'s anatomy captured by the imaging device.

5. The apparatus of claim 3, wherein the imaging device captures a three dimensional image of the patient'"'"'s anatomy and wherein the circuitry is configured to overlay the map of the route of the nerve in three dimensions such that the route of the nerve within the patient'"'"'s anatomy is identified in three dimensions.

6. The apparatus of claim 3, wherein the imaging device comprises one or more of an imaging device selected from an x-ray device, a computerized axial tomography device, a magnetic resonance imaging device, and an ultrasound device.

9. The apparatus of claim 1, wherein at least one of the first, second or third stimulation electrode is disposed at a stimulating site on a surgical dilator.

10. The apparatus of claim 1, wherein the circuitry is configured to identify a location on the nerve by finding an intersection of at least two loci of potential sites, each locus being determined by the position information of each stimulation electrode and the calculated distance between the electrode and the nerve.

11. The apparatus of claim 10, wherein each locus of potential sites is one of a spherical or an elliptical shape based on the electrical field associated with each electrode.

12. The apparatus of claim 1, wherein the circuitry is configured to map the route by one of connecting the identified location on the nerve and an additional location on the nerve or fitting a curve that is determined from the identified location and the additional location on the nerve.

13. The apparatus of claim 12, wherein the curve is a least squares fitting curve.

16. The apparatus of claim 2, wherein the first, second and third stimulation electrodes are configured to be moved independently.

17. The apparatus of claim 1, wherein the first, second and third stimulation electrodes are mounted to a mounting member in a triangular pattern.

18. The apparatus of claim 1, wherein a stimulation current I is delivered sequentially to each of the first, second or third stimulation electrodes.

19. The apparatus of claim 1, wherein a stimulation current I is simultaneously delivered to two or more of the first, second or third stimulation electrodes.

7. A method for mapping the location of a nerve, the method comprising:

stimulating a nerve with a stimulation current from a first stimulation electrode configured to stimulate the nerve from a first position, a second stimulation electrode configured to stimulate the nerve from a second position, and a third stimulation electrode configured to stimulate the nerve from a third position, each of the first, second and third stimulation electrodes remaining stationary during stimulation of the nerve from the first, second and third positions, and wherein each of the first, second, and third stimulation electrodes is a discrete elongated member configured to penetrate tissue;

detecting a muscle reaction, the muscle reaction resulting from stimulation of the nerve by the first, second and third stimulation electrodes;

calculating a first, second, and third distance corresponding to the distances between the first, second and third stimulation electrodes and the nerve using information associated with the stimulation that elicits the muscle reaction;

identifying a location on the nerve using the first, second and third distances and position information of the first, second and third stimulation electrodes for each of the first, second and third distances; and

mapping a route of the nerve in three dimensions using the identified location.

8. The method of claim 7, further comprising:

capturing an image of a patient'"'"'s anatomy; and

overlaying a map of the route of the nerve on the image of the patient'"'"'s anatomy.

14. The method of claim 7, wherein the location on the nerve is identified by finding an intersection of at least two loci of potential sites, each locus being determined by the position information of each stimulation electrode and the calculated distance between the electrode and the nerve.

15. The method of claim 14, wherein each locus of potential sites is one of a spherical or an elliptical shape based on the electrical field associated with each electrode.