Folded Antenna For Implanted Medical Device

Abstract

A folded monopole RF telemetry antenna is contained within a dielectric portion of an implantable medical device housing, which dielectric portion can be a biocompatible epoxy. The monopole antenna is formed from a wire or strip of conductive material which may be conformed inside the outer boundary of the epoxy housing. One end of the monopole antenna is free inside the epoxy, the other end of the antenna is electrically coupled to the circuit ground which, in turn, is connected to the metal housing portion, acting as a ground plane. The length of the antenna can be sized to be self-resonating at a frequency of about 403.5 MHz with at least a 3 MHz bandwidth.

1 . An implantable medical device, comprising:
 a housing comprising a dielectric portion; and   an antenna with a folded portion and positioned within the dielectric portion, wherein transmissions from the folded portion are receivable outside the dielectric portion.   
   
   
       2 . The implantable medical device of  claim 1 , wherein the dielectric portion of the housing comprises a curved region, and wherein the folded portion of the antenna comprises first and second arcuate portions that conform to the curved region. 
   
   
       3 . The implantable medical device of  claim 1 , wherein the antenna is embedded in the dielectric portion of the housing. 
   
   
       4 . The implantable medical device of  claim 1 , further comprising a conductive housing portion. 
   
   
       5 . The implantable medical device of  claim 4 , wherein the conductive housing portion comprises a tissue stimulation circuit. 
   
   
       6 . The implantable medical device of  claim 1 , wherein the folded portion comprises a first section and a second section substantially parallel to each other. 
   
   
       7 . An implantable medical device, comprising:
 a housing comprising a dielectric portion; and   an antenna, with a folded portion comprising first and second portions, the folded portion positioned entirely within the dielectric portion.   
   
   
       8 . The implantable medical device of  claim 7 , wherein the dielectric portion includes a curved region, and wherein the first and second potions are arcuate and extend along the curved region. 
   
   
       9 . The implantable medical device of  claim 7 , wherein the first arcuate portion is in a first plane and the second arcuate portion is in a second plane substantially parallel to the first plane. 
   
   
       10 . The implantable medical device of  claim 7 ,
 wherein the housing further comprises a conductive portion, and   wherein the implantable medical device further comprises a transmitter/receiver circuit, connected to the conductive portion of the housing and operably connected to the antenna.   
   
   
       11 . The implantable medical device of  claim 10 , wherein the conductive portion of the housing provides a ground plane for the antenna. 
   
   
       12 . The implantable medical device of  claim 7 , wherein the antenna is self-resonating about a predetermined frequency range. 
   
   
       13 . The implantable medical device of  claim 7 , further comprising a conductive housing portion. 
   
   
       14 . The implantable medical device of  claim 13 , wherein the conductive housing portion comprises a tissue stimulation circuit. 
   
   
       15 . The implantable medical device of  claim 7 , wherein the folded portion comprises a first section and a second section, substantially parallel to each other. 
   
   
       16 . An implantable medical device, comprising:
 a housing comprising a dielectric portion;   an antenna, positioned entirely within the dielectric portion and having a folded portion with a fold between a first end and a second end of the folded portion, the first end and the second end closer to each other than to the fold.   
   
   
       17 . The implantable medical device of  claim 16 , wherein the folded portion conforms to a curved region of the dielectric portion. 
   
   
       18 . The implantable medical device of  claim 16 , wherein the antenna is embedded in the dielectric portion of the housing. 
   
   
       19 . The implantable medical device of  claim 16 , further comprising a conductive housing portion. 
   
   
       20 . The implantable medical device of  claim 19 , wherein the conductive housing portion comprises a tissue stimulation circuit. 
   
   
       21 . The implantable medical device of  claim 16 , wherein the folded portion comprises a first section and a second section, substantially parallel to each other.