Intraoperative neurophysiological monitoring system
An intraoperative neuromonitoring system for evaluating nerve function via a plurality of neural monitoring modalities includes an invasive medical instrument, a plurality of stimulating electrodes, a plurality of peripheral sensors, a patient module, and a control unit in communication with the patient module. The control unit is configured to maintain a range of acceptable values for each of a plurality of different neural monitoring modalities, determine, for each of the plurality of different neural monitoring modalities, whether the respective modality is within the range of acceptable values for that respective modality based on the indication of neuromuscular activity from one or more of the plurality of peripheral sensors, and provide an indication on a common screen displayed via the display, whether each respective neural monitoring modality is inside or outside of the range of acceptable values for that modality.
1 . A method of evaluating nerve function via a plurality of neural monitoring modalities, the method comprising:
applying a first electrical stimulus within a surgical target site of a patient via a first electrode provided on a surgical access instrument during a surgical procedure;
providing a second electrical stimulus via a plurality of peripheral electrodes acting as stimulating electrodes, the plurality of peripheral electrodes located apart from the surgical target site and the surgical access instrument;
monitoring neuromuscular activity of the patient via a plurality of peripheral sensors disposed on the patient for an indication of neuromuscular activity, each peripheral sensor of the plurality of peripheral sensors being one of: a recording peripheral electrode of the plurality of peripheral electrodes and a mechanical sensor, the recording peripheral electrode being a particular peripheral electrode of the plurality of peripheral electrodes acting as a recording electrode;
determining a nerve conduction velocity (NCV) measurement based on reception of the second electrical stimulus within the surgical target site by a second electrode applied on the surgical access instrument, and the indication of neuromuscular activity from one or more of the plurality of peripheral sensors;
providing an indication via a display if the NCV measurement is within a predefined range;
detecting a neuromuscular response from the indication of neuromuscular activity, the neuromuscular response comprising at least one of a somatosensory evoked potential (SSEP) response; a motor evoked potential (MEP) response; a spontaneous electromyography (EMG) response, a triggered EMG response, or a mechanomyography (MMG) response; and
providing an indication of the detected neuromuscular response via the display.
2 . The method of claim 1 , further comprising determining a minimum electrical current for the first electrical stimulus provided by the surgical access instrument that is required to elicit a sensed neuromuscular response from at least one of the plurality of peripheral sensors.
3 . The method of claim 1 , wherein the surgical access instrument comprises a nerve root retractor having a curved distal end portion with a concave inner surface, and wherein the first electrode is disposed on the concave inner surface; the method further comprising:
contacting a nerve root of a nerve with concave inner surface, and wherein the applied first electrical stimulus is applied directly to the nerve via the first electrode.