Neurophysiologic monitoring system

• US 8,255,045 B2
• Filed: 04/03/2008
• Issued: 08/28/2012
• Est. Priority Date: 04/03/2007
• Status: Active Grant

• Current Assignee: Nuvasive Incorporated
• Original Assignee: Nuvasive Incorporated
• Inventors: Gharib, James, Farquhar, Allen, Layman, Doug, Scholl, Thomas, Kim, Albert, Pothier, Albert, Miles, Patrick, Gorek, Josef, Peterson, Mark
• Primary Examiner(s): DOUGHERTY, SEAN PATRICK
• Application Number:
  US12/080,630
• Publication Number:
  US 20090054804A1
• Time in Patent Office: 1,608 Days
• Field of Search: 600/546, 600/547, 600/554, 606/32, 606/41, 607/2, 607/48
• US Class Current: 600/547
• CPC Class Codes: A61B 17/00 Surgical instruments, devices or methods, e.g. tourniquets A61B18/00 takes precedence; contraceptive devices, pessaries, or applicators therefor A61F6/00; eye surgery A61F9/007; ear surgery A61F11/00
• CPC Class Codes: A61B 17/1626 Control means; Display units
• CPC Class Codes: A61B 17/1671 for the spine
• CPC Class Codes: A61B 17/1757 for the spine
• CPC Class Codes: A61B 2017/00022 Sensing or detecting at the treatment site
• CPC Class Codes: A61B 2017/00026 Conductivity or impedance, e.g. of tissue
• CPC Class Codes: A61B 34/20 Surgical navigation systems; Devices for tracking or guiding surgical instruments, e.g. for frameless stereotaxis
• 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 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• 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 5/407 Evaluating the spinal cord A61B5/4896 takes precedence
• CPC Class Codes: A61B 5/4566 Evaluating the spine A61B5/4561 takes precedence
• CPC Class Codes: A61B 5/4893 Nerves
• CPC Class Codes: A61B 5/7271 Specific aspects of physiological measurement analysis A61B5/316, A61B5/349 and A61B5/374 take precedence
• CPC Class Codes: A61B 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/7455 characterised by tactile indication, e.g. vibration or electrical stimulation
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61N 1/0551 : Spinal or peripheral nerve electrodes

Abstract

The present invention relates to a system and methods generally aimed at surgery. More particularly, the present invention is directed at a system and related methods for performing surgical procedures and assessments involving the use of neurophysiology.

Claims

1. A system for avoiding harm to nervous tissue during surgery, comprising:

an instrument capable of advancement to a surgical target site and configured to deliver a stimulation signal at least one of while advancing to said target site and after reaching said target site; and

a processing system programmed with a set of at least three threshold ranges and configured to direct a first stimulation signal to said instrument at a first magnitude corresponding to a boundary between a pair of said ranges, direct a second stimulation signal at a second magnitude corresponding to a boundary between a different pair of said ranges, and to measure at least one response of nerves depolarized by said stimulation signals to indicate at least one of nerve proximity and pedicle integrity.

2. The system of claim 1, wherein the at least one response of said depolarized nerves is measured by monitoring EMG waveforms of myotomes associated with said depolarized nerves.

3. The system of claim 1, wherein said system includes a display for communicating said at least one of nerve proximity and pedicle integrity.

4. The system of claim 3, wherein said system indicates at least one of nerve proximity and pedicle integrity by displaying at least one of the colors red, yellow, and green.

5. The system of claim 4, wherein said processing system automatically determines a stimulation threshold after displaying said one of red, yellow, and green.

6. The system of claim 5, wherein said processing system augments the display of said one of red, yellow, and green with a numerical value after determining said threshold.

7. The system of claim 1, wherein said instrument is a device for forming a hole in a pedicle.

8. The system of claim 7, wherein said instrument is further coupled to an orientation sensor operable to determine a first angular relationship in a first plane between said sensor and a reference direction and operable to determine a second angular relationship in a second plane between said sensor and said reference direction.

9. The system of claim 8, wherein said orientation sensor is communicatively linked to said processing system.

10. The system of claim 8, wherein said processing unit communicates information to a user regarding at least one of said determined first and second angular relationships between said sensor and said reference direction.

11. The system of claim 1, wherein said instrument is part of a system for establishing an operative corridor to a surgical target site.

12. The system of claim 11, wherein said operative corridor is a lateral approach to a spinal target site.

13. The system of claim 12, wherein said instrument is further coupled to an orientation sensor operable to determine a first angular relationship in a first plane between said sensor and a reference direction and operable to determine a second angular relationship in a second plane between said sensor and said reference direction, wherein said orientation sensor is communicatively linked to said processing system, and said processing unit communicates information to a user regarding at least one of said determined first and second angular relationships between said sensor and said reference direction.

14. The system of claim 1, wherein an individualized closed circuit is formed between the instrument and the processing system.

15. The system of claim 14, wherein at least one of said processing system and said instrument possess an indicator when said closed circuit is formed.

16. The system of claim 15, wherein said indicator is an LED.

17. The system of claim 1, comprising a plurality of sensors for measuring said nerve responses.

18. The system of claim 17, wherein said plurality of sensors comprises at least one of an anode and a common electrode.

19. The system of claim 18, wherein said plurality of sensors connect to said processing system through a single connector.

20. The system of claim 19, wherein said single connector comprises an identifier that is recognized by said processing unit.

21. The system of claim 20, wherein the identification of said connector alters system parameters employed by said processing system.

22. The system of claim 18, wherein the status of said sensors is checked prior to measuring said nerve responses.

23. The system of claim 22, wherein said status is checked with an impedance measurement.

24. The system of claim 23, wherein the status of every sensor is determined independently from the other sensors.

25. The system of claim 24, wherein said anode sensor switches to a cathode to measure impedance.

26. The system of claim 18, further comprising at least one additional sensor not for measuring nerve responses.

27. The system of claim 26, wherein said sensor is a stimulation electrode.

28. The system of claim 27, wherein said sensor delivers stimulation to a peripheral nerve.

29. The system of claim 28, said sensor delivers stimulation signals to the motor cortex.

30. The system of claim 1, wherein said processing system is further configured to:

(a) deliver an electrical stimulation signal to the motor cortex of a patient;

(b) receive evoked neuromuscular response data from a sensor employed on the patient;

(c) assess spinal cord health by identifying a relationship between the stimulation signal and the neuromuscular response; and

(d) communicate the relationship between the stimulation signal and the neuromuscular response to a user via at least one of alpha-numeric indicia and audio.

31. The system of claim 1, wherein said processing system is further configured to:

(a) deliver an electrical stimulation signal to a peripheral nerve of the patient;

(b) measure an action potential related to said stimulation signal;

(c) assess spinal cord health by identifying a relationship between the stimulation signal and the measured action potential; and

(d) communicate the relationship between the stimulation signal and the action potential response to a user via at least one of alpha-numeric indicia and audio.

32. The system of claim 30, wherein said processing system is further configured to:

(a) deliver an electrical stimulation signal to a peripheral nerve of the patient;

(b) measure an action potential related to said stimulation signal;

(c) assess spinal cord health by identifying a relationship between the stimulation signal and the measured action potential; and

(d) communicate the relationship between the stimulation signal and the action potential response to a user via at least one of alpha-numeric indicia and audio.