Method and Apparatus for Measurement of Neural Response

Abstract

A method for determining a desired location at which to apply a neural therapy. An array of electrodes is positioned proximal to neural tissue. A stimulus is applied from the array which evokes a neural compound action potential response in the neural tissue proximal to the array. A plurality of electrodes of the array simultaneously obtain respective measurements of the neural compound action potential response. From the measurements of the neural compound action potential response a desired location for a neural therapy is determined.

1 . A method for determining a desired location at which to apply a neural therapy, the method comprising:
 positioning an array of electrodes proximal to neural tissue;   applying a stimulus from the array which evokes a neural compound action potential response in the neural tissue proximal to the array;   using a plurality of electrodes of the array to simultaneously obtain respective measurements of the neural compound action potential response; and   determining from the measurements of the neural compound action potential response a desired location for a neural therapy.   
     
     
         2 . The method of  claim 1  wherein the array comprises a large number of electrodes configured to obtain simultaneous measurements of a neural response, in order to yield fine spatial resolution of the neural sensitivity map of the area alongside the array. 
     
     
         3 . The method of  claim 2  wherein the array comprises 24 electrodes arranged in 3 columns and 8 rows. 
     
     
         4 . The method of  claim 1  when applied intra-operatively in order to provide intra-operative information regarding the neural response. 
     
     
         5 . The method of  claim 4 , when used for intra-operative DREZ localization, by generating a neural sensitivity map around the DREZ in order to guide DREZ lesioning. 
     
     
         6 . The method of  claim 5 , wherein DREZ lesioning is performed in progressive increments, iteratively with neural sensitivity mapping, whereby the ongoing neural sensitivity mapping provides a progressive intra-operative gauge of the effects of lesioning. 
     
     
         7 . The method of  claim 5  wherein the DREZ lesioning is performed by RF ablation, applied from the same electrode array as is used for the sensitivity mapping. 
     
     
         8 . The method of  claim 7 , when used iteratively with cortical lesioning, so as to give a progressive measure of the efficacy of incremental lesioning of the origin site. 
     
     
         9 . The method of  claim 1 , when used intra-operatively in order to optimize the position of an electrode or electrode array being implanted. 
     
     
         10 . The method of  claim 9 , when used for intra-operative positioning of an electrode array being implanted, laterally relative to the spinal cord. 
     
     
         11 . The method of  claim 9 , when used for intra-operative caudorostral positioning of an electrode array being implanted, relative to the spinal cord. 
     
     
         12 . The method of  claim 1  when used intra-operatively and wherein intra-operative information representing the measurements of the neural compound action potential response is presented to a surgeon by way of an amplitude meter. 
     
     
         13 . The method of  claim 1  when used post-operatively to give ongoing guidance as to the suitability of the site of the neural therapy. 
     
     
         14 . The method of  claim 13 , further comprising determining when manual or automated re-fitting of a therapeutic device is required, to cause a site of the neural therapy to be revised in response to the ongoing measurements. 
     
     
         15 . The method of  claim 13  wherein a selection of which electrode(s) to use to apply a therapeutic stimulus is post-operatively altered in response to an updated map of neural sensitivity as measured at each electrode. 
     
     
         16 . The method of  claim 1  wherein the stimulus is applied under the control of a remote control of the implanted array. 
     
     
         17 . A system for determining a desired location at which to apply a neural therapy, the system comprising:
 an array of electrodes configured to be positioned proximal to neural tissue;   a control unit configured to cause application of a stimulus from the array which evokes a neural compound action potential response in the neural tissue proximal to the array, the control unit further configured to simultaneously obtain a plurality of measurements of the neural compound action potential response from a plurality of electrodes of the array, and the control unit further configured to determine from the measurements of the neural compound action potential response a desired location for a neural therapy.