System and methods for performing neurophysiologic assessments with pressure monitoring

• US 20070021682A1
• Filed: 07/20/2006
• Published: 01/25/2007
• Est. Priority Date: 07/20/2005
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Martinelli, Scot, Gharib, James, Farquhar, Allen, Ivanko, David, Verhage, Benjamin
• Granted Patent: US 8,740,783 B2
• Time in Patent Office: Days
• US Class Current: 600/546
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/388 Nerve conduction study, e.g. detecting action potential of peripheral nerves
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/395 Details of stimulation, e.g. nerve stimulation to elicit EMG response
• CPC Class Codes: A61B 5/4029 for evaluating the peripheral nervous systems A61B5/24 takes precedence
• CPC Class Codes: A61B 5/4893 Nerves

Abstract

Systems and methods for performing neurophysiologic assessments of neural tissue including nerve pathology monitoring which may or may not be augmented by adding the ability to assess or monitor the pressure being exerted upon a nerve or nerve root before, during and/or after retraction.

Claims

1. A system for assessing the pathology of a nerve, comprising:

at least one stimulation electrode, said stimulation electrode configured to deliver an electrical stimulation signal to a nerve within a patient;

at least one sensor configured to detect neuromuscular responses evoked by said stimulation signal; and

a nerve retractor equipped with a pressure sensor.

2. The system of claim 1, wherein said pressure sensor is communicatively linked to a processing unit and said processing unit calculates the pressure exerted on a nerve by said nerve retractor.

3. The system of claim 2, wherein said processing unit further includes a display, wherein said display provides at least one of alpha-numeric and graphic indicia relating to said calculated pressure.

4. The system of claim 3, wherein said alpha-numeric and graphic indicia includes at least one of a maximum pressure value, time value, color, 3-dimesional pressure map, 2-dimensional pressure map, chart, and a graph.

5. The system of claim 2, wherein said stimulation electrode and said sensor are communicatively linked to a control unit and said control unit is configured to determine a relationship between said stimulation signal and said neuromuscular response.

6. The system of claim 5, wherein said control unit includes a display and said display provides at least one of alpha-numeric and graphic indicia relating to said identified relationship.

7. The system of claim 5, wherein said identified relationship is the lowest stimulation current necessary to evoke a neuromuscular response.

8. The system of claim 7, wherein said control unit is further configured to perform a threshold hunting algorithm to identify the lowest stimulation current necessary to evoke a neuromuscular response.

9. The system of claim 8, wherein said stimulation electrode is positioned on said nerve retractor.

10. The system of claim 5, wherein said control unit and said processing unit are a single unit.

11. The system of claim 5, wherein said control unit and said processing unit are distinct units.

12. A method for assessing the pathology of a nerve, comprising the steps of:

retracting a nerve within a patient using a nerve retractor equipped with a pressure sensor;

stimulating said nerve with an electrical stimulation signal delivered by at least one stimulation electrode; and

using at least one sensor to detect neuromuscular responses evoked by said stimulation signal.

13. The method of claim 12, wherein said pressure sensor is linked to a processing unit and said processing unit calculates the pressure exerted on said nerve by said nerve retractor.

14. The method of claim 13, wherein said processing unit further includes a display, wherein said display provides at least one of alpha-numeric and graphic indicia relating to said calculated pressure.

15. The method of claim 14, wherein said alpha-numeric and graphic indicia includes at least one of a maximum pressure value, time value, color, 3-dimesional pressure map, 2-dimensional pressure map, chart, and a graph.

16. The method of claim 13, comprising the additional steps of:

using a control unit communicatively linked to said stimulation electrode and said sensor to identify a relationship between said stimulation signal and said neuromuscular response.

17. The method of claim 16, wherein said control unit includes a display and said display provides at least one of alpha-numeric and graphic indicia relating to said identified relationship.

18. The method of claim 16, wherein said identified relationship is the lowest stimulation current necessary to evoke a neuromuscular response.

19. The method of claim 18, wherein said control unit is configured to perform a threshold hunting algorithm to identify the lowest stimulation current necessary to evoke a neuromuscular response.

20. The method of claim 12, wherein said stimulation electrode is positioned on said nerve retractor.

21. The method of claim 16, wherein said control unit and said processing unit are a single unit.

22. The method of claim 16, wherein said control unit and said processing unit are distinct units.