Heat pipe nerve cooler

Abstract

The invention provides a method and apparatus for producing reversible focal hypothermia of the nervous system to control chronic pain. Nerve conduction is blocked by mild cooling (0 to 25° C.), or hypothermia. At these temperatures, nerve tissue is not destroyed and recovers completely when cooling is terminated, such that the treatment is reversible. By blocking conduction in pain nerves, pain sensation is eliminated in a manner analogous to drugs such as lidocaine that also block nerve conduction to provide anesthesia. The invention can be applied to a variety of conditions such as urge incontinence, muscle spasticity, and epilepsy. Many of these disorders are mediated by nerve and nervous tissue that could be interrupted by cooling. In addition, neurologic dysfunction found in multiple sclerosis may improve by cooling of the nerves. The method and apparatus may be used to cool areas of the nervous system affected by multiple sclerosis to allow more normal functions.

What is claimed is:  
     
         1 . An apparatus for cooling a portion of tissue, comprising: 
 an evaporator to be placed in thermal communication with a portion of tissue;    a condenser disposed in thermal communication with a source or sink of heat, the condenser including an upper chamber and a lower chamber; and    a conduit disposed between the evaporator and the condenser, the conduit including a wick structure, to communicate working fluid between the two.    
     
     
         2 . The apparatus of  claim 1 , wherein the lower chamber is separated from the upper chamber by a porous structure.