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 surgical target site and after reaching said surgical 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   measure responses of nerves depolarized by said stimulation signals to indicate at least one of nerve proximity and pedicle integrity,   wherein the processing system is 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 system is configured to communicate 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   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   wherein said processing system 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 system. 
     
     
         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 a 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 a patient's motor cortex;   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 patient's peripheral nerve;   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 an action potential response to a user via at least one of alpha-numeric indicia and audio.   
     
     
         20 . A system comprising:
 a processing system programmed with a set of at least three threshold ranges and configured to:   direct a first stimulation signal to an instrument at a first magnitude corresponding to a boundary between a pair of the ranges;   direct a second stimulation signal at a second magnitude corresponding to a boundary between a different pair of the ranges; and   measure the response of nerves depolarized by the stimulation signals to indicate at least one of nerve proximity and pedicle integrity,   wherein the processing system is 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.   
     
     
         21 . The system of  claim 20 , comprising:
 a plurality of sensors for measuring the nerve responses that include at least one of an anode and a common electrode,   wherein the plurality of sensors connect to the processing system through a single connector;   wherein the single connector comprises an identifier;   wherein the processing system is programmed to recognize the identifier and alter system parameters based thereon;   wherein the status of the sensors is checked with an impedance measurement prior to measuring the nerve responses.   
     
     
         22 . The system of  claim 20 , wherein the processing system is further configured to:
 deliver an electrical stimulation signal to a patient's motor cortex;   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.   
     
     
         23 . The system of  claim 20 , wherein the processing system is further configured to:
 deliver an electrical stimulation signal to a peripheral nerve of the patient;   measure an action potential related to the 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 an action potential response to a user via at least one of alpha-numeric indicia and audio.   
     
     
         24 . A method comprising:
 advancing an instrument to a surgical target site;   directing a first stimulation signal to the instrument at a first magnitude corresponding to a value between a predetermined pair of ranges;   directing a second stimulation signal at a second magnitude corresponding to a value between a different predetermined pair of ranges;   measuring the response of nerves depolarized by the stimulation signals to indicate at least one of nerve proximity and pedicle integrity; and   performing a first neurophysiologic testing function selected from the group consisting 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; and   performing a second neurophysiologic testing function selected from the group consisting 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,   wherein the first neurophysiologic testing function is different from the second neurophysiologic testing function.   
     
     
         25 . The method of  claim 24 , further comprising:
 determining a first angular relationship in a first plane between a sensor of the instrument and a reference direction;   determining a second angular relationship in a second plane between the sensor and the reference direction; and   communicating information to a user regarding one or both of the first angular relationship and the second angular relationship.   
     
     
         26 . The method of  claim 24 , further comprising:
 delivering an electrical stimulation signal to a patient's motor cortex;   receiving evoked neuromuscular response data from a sensor employed on the patient;   assessing spinal cord health by identifying a relationship between the stimulation signal and the neuromuscular response; and   communicating the relationship between the stimulation signal and the neuromuscular response to a user via at least one of alpha-numeric indicia and audio.   
     
     
         27 . The method of  claim 24 , further comprising:
 delivering an electrical stimulation signal to a patient's peripheral nerve;   measuring an action potential related to the stimulation signal;   assessing spinal cord health by identifying a relationship between the stimulation signal and the measured action potential; and   communicating the relationship between the stimulation signal and an action potential response to a user via at least one of alpha-numeric indicia and audio.