Radiopaque electrical needle

Abstract

A method and apparatus are disclosed for improving accuracy of placement of needles during delivery of high frequency signals near a neural structure to form lesions. The apparatus includes a needle that can deliver electrical current where a portion of the needle is electrically insulated and a portion of the needle is exposed and electrically active, thereby causing lesions. The needle includes radiopaque marking to differentiate the electrically insulated region from the exposed region, allowing it to be better discerned in the body under fluoroscopy.

We claim:  
     
         1 . A needle for insertion into a patient's body comprising: 
 an electrically insulated shaft having an electrically conductive tip portion; and    a radiopaque marker associated with at least one of the shaft and the tip portion.    
     
     
         2 . The needle of  claim 1 , wherein the radiopaque marker is located on at least a portion of the periphery of the shaft.  
     
     
         3 . The needle of  claim 1 , wherein the radiopaque marker is band-shaped.  
     
     
         4 . The needle of  claim 1 , wherein the shaft comprises an insulating coating.  
     
     
         5 . The needle of  claim 4 , where the insulating coating covers the radiopaque marker.  
     
     
         6 . The needle of  claim 4 , wherein the insulating coating is radiopaque.  
     
     
         7 . The needle of  claim 1 , wherein the needle is operable to connect to an energy source.  
     
     
         8 . The needle of  claim 7 , wherein the needle is operable to deliver high frequency electrical current.  
     
     
         9 . The needle of  claim 1 , wherein the tip portion is beveled and the radiopaque marker is shaped to indicate the direction of the tip.  
     
     
         10 . The needle of  claim 1 , wherein the radiopaque marker comprises at least two bands defining the tip portion.  
     
     
         11 . The needle of  claim 1 , wherein the tip portion is radiopaque.  
     
     
         12 . The needle of  claim 1 , wherein the insulated shaft is radiopaque.  
     
     
         13 . The needle of  claim 1  comprising a stylet and wherein the shaft is hollow for receiving the stylet and wherein the radiopaque marker is associated with at least one of the shaft, the tip portion and the stylet.  
     
     
         14 . A needle for insertion into a patient's body comprising: 
 an electrically insulated hollow shaft having an electrically conductive tip portion; and    a stylet having a radiopaque marker, the stylet operable to be located in the needle during insertion and operable to be removed therefrom after insertion.    
     
     
         15 . An apparatus for delivering high frequency electrical current to neural structures comprising: 
 an energy source for supplying high frequency electrical current;    a needle connected to the energy source comprising an electrically insulated shaft having an electrically conductive tip portion located at one end of the shaft and a radiopaque marker associated with at least one of the shaft and the tip portion; and    at least one reference electrode for completing the electrical circuit.    
     
     
         16 . A method for positioning a needle for delivering high frequency electrical current to neural structures comprising the steps of: 
 (i) providing a needle operable for connection to an energy source, said needle comprising an electrically insulated shaft having an electrically conductive tip portion located at one end of the shaft and a radiopaque marker associated with at least one of the shaft and the tip portion;    (ii) positioning the needle to a location to treat the neural structure; and    (iii) verifying the position of the needle using the radiopaque marker.    
     
     
         17 . The method of  claim 16  comprising: 
 (iv) delivering high frequency electrical current through the needle to the neural structure.  
 
     
     
         18 . The method of  claim 16 , wherein the needle comprises a stylet received within the shaft and the radiopaque marker is associated with at least one of the shaft the tip portion and the stylet.  
     
     
         19 . The method of  claim 18  comprising removing the stylet prior to delivering high frequency electrical current.  
     
     
         20 . The method of  claim 19  comprising inserting an electrical probe into the needle and delivering high frequency electrical current via the electrical probe.