Heat pipe nerve cooler

• US 6,364,899 B1
• Filed: 06/09/1999
• Issued: 04/02/2002
• Est. Priority Date: 01/23/1998
• Status: Expired due to Fees

• Current Assignee: Innercool therapies Incorporated (Taxus Cardium Pharmaceuticals Group, Inc.)
• Original Assignee: Innercool therapies Incorporated (Taxus Cardium Pharmaceuticals Group, Inc.)
• Inventors: Dobak, John D. III
• Primary Examiner(s): Kearney, R.
• Application Number:
  US09/328,854
• Time in Patent Office: 1,028 Days
• Field of Search: 607/96, 607/101, 607/105, 607/106, 607/107, 607/113, 607/114, 606/20, 606/21, 606/22, 606/23, 606/24, 606/25, 606/26
• US Class Current: 607/113
• CPC Class Codes: A61B 18/02 by cooling, e.g. cryogenic techniques devices for cooling specific reflex points of the body within cell-life limits A61H39/06
• CPC Class Codes: A61B 2017/00292 mounted on or guided by flexible, e.g. catheter-like, means
• CPC Class Codes: A61B 2018/0212 using an instrument inserted into a body lumen, e.g. catheter
• CPC Class Codes: A61B 2018/0262 using a circulating cryogenic fluid
• CPC Class Codes: A61F 2007/0056 for cooling
• CPC Class Codes: A61F 2007/126 for invasive application, e.g. for introducing into blood vessels
• CPC Class Codes: A61F 7/12 Devices for heating or cooling internal body cavities

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.

Claims

1. A method of cooling a portion of a spinal cord of a patient, comprising:

delivering a portion of a heat pipe to a spinal cord of a patient, the heat pipe including an evaporator and a condenser, including disposing the evaporator at least in partial thermal communication with the spinal cord; and

cooling the evaporator by passing a working fluid between the evaporator and the condenser.

2. The method of claim 1, wherein the delivering further comprises disposing the evaporator at least in partial thermal communication with the dorsal root entry zone of the spinal cord.

3. The method of claim 1, further comprising passing the working fluid between the evaporator and the condenser through a conduit.

4. The method of claim 3, wherein the conduit is a tube.

5. The method of claim 3, wherein the conduit is a wick structure.

6. The method of claim 3, further comprising implanting the condenser within the patient.

7. The method of claim 3, further comprising locating the condenser externally of the patient.

8. The method of claim 6, wherein the condenser has an insulated lower chamber into which the conduit enters and an upper chamber into which the return tube enters, the lower and upper chambers separated by a porous structure, farther comprising passing the working fluid in gaseous form from the evaporator through the return tube within the conduit to the upper chamber, condensing the working fluid at least partially from the gaseous form into the liquid form, passing the working fluid from the upper chamber to the lower chamber through the porous structure, and passing the condensed working fluid from the lower chamber to the evaporator through the conduit.

9. The method of claim 8, further comprising disposing the upper chamber in thermal communication with a cold source.

10. The method of claim 1, further comprising disposing the evaporator adjacent the dura mater.

11. The method of claim 10, further comprising disposing the evaporator between the spinal cord and the dura mater.

12. The method of claim 10, further comprising disposing the evaporator on the side of the dura mater opposite the spinal cord.