Catheter system cannula

Abstract

A radiofrequency cannula can be configured for placement in the epidural space.

1 . A cannula that includes a hollow shaft, the shaft including a proximal end and a distal end, the distal end of the shaft including an electrically-conductive tip that conducts radiofrequency current to tissue, the distal end of the shaft including a bevel that is configured for introduction of a catheter into the epidural space. 
     
     
         2 . The apparatus of  claim 1  wherein the bevel is configured for introduction of a catheter into the epidural space. 
     
     
         3 . The apparatus of  claim 1  wherein the bevel's heel and inner edge are rounded. 
     
     
         4 . The apparatus of  claim 1  wherein the cannula includes a connection between the conductive tip and an output pole of a radiofrequency generator. 
     
     
         5 . The apparatus of  claim 4  wherein the output pole is the reference jack of the radiofrequency generator. 
     
     
         6 . The apparatus of  claim 1  that additionally includes a radiofrequency electrode configured to electrify the radiofrequency cannula and to monitor a temperature within the uninsulated tip of the radiofrequency cannula. 
     
     
         7 . The apparatus of  claim 6  wherein the electrode is a catheter-style electrode configured to pass through the cannula's hollow shaft and to protrude from the bevel of the cannula. 
     
     
         8 . The apparatus of  claim 7  wherein the electrode is configured for use in the epidural space. 
     
     
         9 . An epidural needle that includes a conductive shaft, wherein the conductive shaft is at least partially covered by electrical insulation. 
     
     
         10 . The apparatus of  claim 9  wherein the shaft includes a distal end that is not covered by electrical insulation. 
     
     
         11 . A system that includes a flexible electrode and an introducer needle, wherein the electrode is configured for placement in the human body and includes at least one conductive region configured for delivery of electric current to the human body; and wherein the introducer needle has a conductive shaft with a proximal and a distal end, the proximal end is covered by electrical insulation, a lumen through which the electrode can pass into the human body, and a bevel whose heel and inner edges are rounded to prevent damage to the electrode. 
     
     
         12 . The apparatus in  claim 11  wherein the electrode includes a shaft having a proximal and a distal end, the proximal end is covered by electrical insulation, and the conductive region is at the distal end. 
     
     
         13 . The apparatus of  claim 11  wherein the electrode and the needle are both configured for delivery of radiofrequency signals to the human body. 
     
     
         14 . The apparatus of  claim 11  wherein the electrode and needle are both configured for placement in the epidural space of the living body. 
     
     
         15 . An epidural needle whose bevel includes at least two surfaces wherein the most distal surface is curved. 
     
     
         16 . An electrode that includes a tissue-piecing shaft and bevel that are configured for placement in the epidural space, wherein a first tip of the shaft conducts radiofrequency current to bodily tissue.