System and methods for performing neurophysiologic assessments during spine surgery

Patent metadata

Field	Value
Publication number	US-11033218-B2
Application number	US-201916449364-A
Country	US
Kind code	B2
Filing date	Jun 22, 2019
Priority date	Feb 2, 2005
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A system and methods for performing neurophysiologic assessments during surgery, such as assessing the health of the spinal cord via at least one of MEP and SSEP monitoring and assessing bone integrity, nerve proximity, neuromuscular pathway, and nerve pathology during spine surgery.

First claim

What is claimed is:

1. A method for performing neurophysiologic assessments during surgery, comprising:
providing a signal to transmit a first set of electrical stimulation signals and a second set of electrical stimulation signals to the motor cortex of a patient via a stimulator, each of said first and second sets of electrical stimulation signals including stimulation signals having different electrical current amplitude;
receiving evoked motor evoked potential response data from at least one sensor, wherein the at least one sensor is configured to detect at least one motor evoked potential response evoked by the first and second sets of electrical stimulation signals;
determining a first lowest stimulation current amplitude for a first channel from the first set of electrical stimulation signals that evokes a motor evoked potential response greater than a threshold level, wherein the first channel is associated with a first sensor of the at least one sensor;
determining a second lowest stimulation current amplitude for a second channel from the second set of electrical stimulation signals that evokes a motor evoked potential response greater than said threshold level, wherein the second channel is associated with a second sensor of the at least one sensor, wherein determining the second lowest stimulation current amplitude is based at least in part on a determination of the lowest stimulation signal amplitude of the first set of electrical stimulation signals that recruited on the second channel and the highest stimulation signal amplitude of the first set of electrical stimulation signals that did not recruit on the second channel; and
displaying an onscreen assessment of a spinal cord health status based on at least one of (i) the determination of the first lowest stimulation current amplitude and (ii) the determination of the second lowest stimulation current amplitude.

2. The method of claim 1 , wherein each of the first and second sets of electrical stimulation signals comprises a predetermined number of pulses separated by an interpulse gap, each pulse having a pulse width.

3. The method of claim 2 , wherein the number of pulses ranges from 1 to 8 monophasic pulses, the interpulse gap ranges from 1 millisecond to 10 milliseconds, and the pulse width ranges from 50 microseconds to 400 microseconds.

4. The method of claim 3 , wherein the monophasic pulses are positive phases pulses for all stimulation signals in the first and second sets of electrical stimulation signals.

5. The method of claim 2 , wherein each of the first and second sets of electrical stimulation signals have amplitudes within a range from 0 milliamps to 1000 milliamps.

6. The method of claim 2 , further comprising:
optimizing at least one stimulation signal from the first and second sets of electrical stimulation signals at least one of before conducting a neurophysiologic assessment of the spinal cord of the patient and after a response to the stimulation signal stops being detected during a neurophysiologic assessment of the spinal cord of the patient.

7. The method of claim 6 , wherein optimizing the at least one stimulation signal comprises modifying at least one of the predetermined number of pulses, the interpulse gap, the pulse width, and the current level before the neurophysiologic assessment of the spinal cord.

8. The method of claim 1 , further comprising:
providing a second signal to transmit a third set of electrical stimulation signals to one or more nerves within the patient via a second stimulator;
receiving evoked neuromuscular response data from the at least one sensor in response to the third set of stimulation signals,
determining a status of at least one of bone integrity, nerve direction, nerve pathology, and neuromuscular pathway integrity by identifying a relationship between a third lowest stimulation current amplitude from the third set of electrical stimulation signals that evokes a neuromuscular response greater than a predefined threshold; and
displaying the status of the at least one of bone integrity, nerve direction, nerve pathology, and neuromuscular pathway integrity.

9. The method of claim 1 , wherein determining at least one of the first lowest stimulation current amplitude and the second lowest stimulation current amplitude further comprises:
establishing a bracket within which at least one of the first lowest stimulation current amplitude and the second lowest stimulation current amplitude is contained; and
successively bisecting the bracket until at least one of the first lowest stimulation current amplitude and the second lowest stimulation current amplitude is determined within a specified accuracy.

10. The method of claim 1 , wherein providing the signal to transmit the first and second sets of electrical stimulation signals to the motor cortex of the patient occurs after receiving a start signal from a bite-block positioned within the patient's mouth, wherein the bite-block contains at least one electrode configured to initiate the start signal.

11. A method for performing neurophysiologic assessments during surgery, comprising:
providing a signal to transmit a first set of electrical stimulation signals to the motor cortex of a patient to perform motor evoked potential monitoring, a second set of electrical stimulation signals to the motor cortex of the patient to perform the motor evoked potential monitoring, and a third set of electrical stimulation signals to one or more peripheral nerves within the patient to perform somatosensory evoked potential monitoring;
receiving data from a plurality of sensors configured to detect one or more responses to the first, second, and third sets of electrical stimulation signals;
determining a first lowest stimulation current amplitude from the first set of electrical stimulation signals that evokes a motor evoked potential response greater than a first threshold level;
determining a second lowest stimulation current amplitude from the second set of electrical stimulation signals that evokes a corresponding neuromuscular response greater than a second threshold level, wherein determining the second lowest stimulation current amplitude is based at least in part on a determination of the lowest stimulation signal amplitude of the first set of stimulation signals that recruited and the highest signal amplitude of the first set of electrical stimulation signals that did not recruit;
determining a third lowest stimulation current amplitude from the third set of electrical stimulation signals delivered that evokes a corresponding neuromuscular response greater than a third threshold level;
displaying an onscreen assessment of a spinal cord health status based on at least one of (i) the determination of the first lowest stimulation current amplitude and (ii) the determination of the second lowest stimulation current amplitude; and
displaying an onscreen assessment of at least one of nerve direction, nerve pathology, and neuromuscular pathway integrity status based on the determination of the third lowest stimulation current amplitude.

12. The method of claim 11 , wherein each stimulation signal of the first set of electrical stimulation signals comprises a predetermined number of pulses separated by an interpulse gap, each pulse having a pulse width.

13. The method of claim 12 , wherein the number of pulses ranges from 1 to 8 monophasic pulses, the interpulse gap ranges from 1 millisecond to 10 millisecond, the pulse width ranges from 50 microseconds to 400 microseconds and the respective current level falls within a range from 0 milliamps to 1000 milliamps.

14. The method o

Assignees

• Nuvasive Inc

Inventors

• Gharib James E
• Farquhar Allen
• Layman Doug

Classifications

• A61B5/4041

  Evaluating nerves condition · CPC title

• A61B5/407 Primary

  Evaluating the spinal cord (for locating the epidural space A61B5/4896) · CPC title

• A61N1/37247

  User interfaces, e.g. input or presentation means · CPC title

• A61N1/0548

  Oral electrodes · CPC title

• A61B5/4504 Primary

  Bones (A61B5/4547 takes precedence) · CPC title