Neurophysiologic monitoring system

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.

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 the response of nerves depolarized by said stimulation signals to indicate at least one of nerve proximity and pedicle integrity, said processing system programmed to perform a plurality of neurophysiologic testing functions including at least two of static pedicle integrity testing, dynamic pedicle integrity testing, nerve proximity detection, neuromuscular pathway assessment, manual motor evoked potential monitoring, automatic motor evoked potential monitoring, somatosensory evoked potential monitoring, and non-evoked monitoring.   
     
     
         2 . The system of  claim 1 , wherein said instrument is a device for forming a hole in a pedicle. 
     
     
         3 . The system of  claim 2 , 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. 
     
     
         4 . The system of  claim 3 , wherein said orientation sensor is communicatively linked to said processing system. 
     
     
         5 . The system of  claim 3 , 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. 
     
     
         6 . The system of  claim 1 , wherein said instrument is part of a system for establishing an operative corridor to a surgical target site. 
     
     
         7 . The system of  claim 6 , wherein said operative corridor is a lateral approach to a spinal target site. 
     
     
         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, 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. 
     
     
         9 . The system of  claim 1 , comprising a plurality of sensors for measuring said nerve responses. 
     
     
         10 . The system of  claim 9 , wherein said plurality of sensors comprises at least one of an anode and a common electrode. 
     
     
         11 . The system of  claim 10 , wherein said plurality of sensors connect to said processing system through a single connector. 
     
     
         12 . The system of  claim 11 , wherein said single connector comprises an identifier that is recognized by said processing unit. 
     
     
         13 . The system of  claim 12 , wherein the identification of said connector alters system parameters employed by said processing system. 
     
     
         14 . The system of  claim 10 , wherein the status of said sensors is checked prior to measuring said nerve responses. 
     
     
         15 . The system of  claim 14 , wherein said status is checked with an impedance measurement. 
     
     
         16 . The system of  claim 15 , wherein the status of every sensor is determined independently from the other sensors. 
     
     
         17 . The system of  claim 1 , further comprising a stimulation electrode, wherein said stimulation electrode is configured to deliver stimulation to a peripheral nerve. 
     
     
         18 . The system of  claim 1 , wherein said processing system is further configured to: deliver an electrical stimulation signal to the motor cortex of a patient; receive evoked neuromuscular response data from a sensor employed on the patient; assess spinal cord health by identifying a relationship between the stimulation signal and the neuromuscular response; and communicate the relationship between the stimulation signal and the neuromuscular response to a user via at least one of alpha-numeric indicia and audio. 
     
     
         19 . The system of  claim 1 , wherein said processing system is further configured to: deliver an electrical stimulation signal to a peripheral nerve of the patient; measure an action potential related to said stimulation signal; assess spinal cord health by identifying a relationship between the stimulation signal and the measured action potential; and 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.