(19) United States
(12) Patent Application Publication (io) Pub. No.: US 2006/0030914 Al
Eggers et al. (43) Pub. Date: Feb. 9,2006
(54) SYSTEM, METHOD AND APPARATUS FOR EVALUATING TISSUE TEMPERATURE
(75) Inventors: Philip E. Eggers, Dublin, OH (US);
John L. Ridihalgh, Columbus, OH
(US); Mark Mayerchak, Bothell, WA
(US); Gary Altman, Kirkland, WA
(US)
Correspondence Address:
Gerald L. Smith
Mueller and Smith, LPA
7700 Rivers Edge Drive
Columbus, OH 43235 (US)
(73) Assignee: Apsara Medical Corporation
(21) Appl. No.: 11/241,202
(22) Filed: Sep. 30, 2005
Related U.S. Application Data
(60) Division ol application No. 10/733,970, filed on Dec. 11, 2003, which is a continuation-in-part ol application No. 10/246,347, filed on Sep. 18, 2002, which is a continuation-in-part ol application No. 10/201,363, filed on Jul. 23, 2002, now abandoned.
Method, system and apparatus for monitoring target tissue temperatures wherein temperature sensors are configured as passive resonant circuits each with a unique resonating signature at monitoring temperatures extending below a select temperature setpoint. The resonant circuits are configured with an inductor component formed ol windings about a lerrite core having a Curie temperature characteristic corresponding with a desired temperature setpoint. By selecting inductor winding turns and capacitance values, unique resonant center frequencies are detectable. Temperature monitoring can be carried out with implants at lower threshold and upper limit temperature responses. Additionally, the lower threshold sensors may be combined with auto-regulated heater implants having Curie transitions at upper temperature limits.
