Abstract

A radio frequency (rf) lesion electrode design with a thermocouple temperature sensor in its distal uninsulated tip is described, having special design features which enable it to be made with very small tip diameters, flexible tip geometrics, very close proximity of the thermocouple sensor to the tissue the temperature of which must be measured, and very accurate and rapid temperature response. The two metal elements which are the two sides of the thermocouple junction, and the thermocouple junction itself are located in part on the external surface of the electrode's lesioning tip, essentially in direct physical contact with the tissue which is to be heated. This externalized sensor design is in contrast to all other temperature monitoring rf lesion electrodes to date where the sensors have been internalized, i.e., built inside the tip and not adjacent to heated tissue. The new design makes possible very small, sharpened-tip electrodes for micro surgical lesion procedures such as in making lesions in the spinal cord, i.e., cordotomies. Tip diameters of much less than 0.3 mm are practical, which is much smaller than previously achieved.