Leadless implantable medical device with fixation antenna member

Abstract

Devices and methods are provided for a leadless implantable medical device (LIMD) comprising a housing. An electrode is disposed on the housing. An electronics circuit is disposed in the housing and is configured to sense cardiac signals, and/or generate and deliver pacing signals to the electrode. A transceiver circuit is disposed in the housing, and is configured to communicate wirelessly with an external device. A fixation antenna electrically separate from the electrode is disposed on a distal portion of the housing and is electrically coupled to the transceiver circuit, and configured to operate as an antenna for communication between the transceiver circuit and the external device.

What is claimed is: 
     
         1 . A method for providing an implantable medical device, comprising:
 providing a device housing having electronic circuits therein;   disposing an electrode on the housing; and   disposing a fixation antenna on a distal end of the housing, the fixation antenna being configured for operation as an antenna to communicate with an external device,wherein the fixation antenna has a predetermined length to tune the fixation antenna to a communication frequency.   
     
     
         2 . The method of  claim 1 , further comprising: connecting a feedthrough assembly to the device housing; connecting the electrode to the feedthrough assembly; and connecting the fixation antenna to the feedthrough assembly. 
     
     
         3 . The method of  claim 1 , wherein the electrode is disposed on a distal portion of the housing. 
     
     
         4 . The method of  claim 1 , further comprising tuning the fixation antenna to communicate in accordance with at least one of a MICS protocol, Bluetooth protocol, BLE protocol, or WiFi protocol. 
     
     
         5 . The method of  claim 1 , further comprising setting a length of the fixation antenna to be a multiple of a wavelength for a frequency for one of  400 MHz or 2.4 GHz. 
     
     
         6 . The method of  claim 1 , further comprising forming the fixation antenna of a material having a deflection DEF=LEN REST /LEN EXTEND  that is no more than 50%, wherein LEN REST  represents a rest length of the fixation antenna along the longitudinal axis when in a rest non-extended state, and LEN EXTEND  represents an extended length of the fixation antenna along the longitudinal axis when deflected to a fully extended state. 
     
     
         7 . The method of  claim 1 , wherein the fixation antenna is electrically separate from the electrode and partially disposed on a distal portion of the housing, the fixation antenna being configured to penetrate cardiac tissue to affix the leadless implantable device to the cardiac tissue, the fixation antenna being electrically coupled to a transceiver circuit and configured to operate as an antenna for communication between the transceiver circuit and the external device. 
     
     
         8 . The method of  claim 7 , wherein: the housing includes a feedthrough, the fixation antenna including a proximal end connected through the feedthrough to the transceiver circuit, and the fixation antenna including a distal end that is electrically open. 
     
     
         9 . The method of  claim 1 , wherein the fixation antenna is configured to operate as a monopole antenna for communication between the transceiver circuit and the external device. 
     
     
         10 . The method of  claim 1 , wherein the fixation antenna includes a body that extends between the proximal and distal ends, the body having a length defined based on a wavelength of a carrier frequency for communication with the external device. 
     
     
         11 . The method of  claim 10 , wherein the length of the body is a quarter multiple of the wavelength of the carrier frequency. 
     
     
         12 . The method of  claim 1 , further comprising shaping a body of the fixation antenna as one of a helix, hook or straight needle. 
     
     
         13 . The method of  claim 1  wherein the fixation antenna has a diameter between 2.5 mm and 5 mm. 
     
     
         14 . A leadless implantable medical device, comprising:
 a housing;   a pacing electrode disposed on a distal portion of the housing;   a fixation antenna disposed on a distal end of the housing, the fixation antenna configured for operation as a monopole antenna to communicate with an external device; and   an electronics circuit disposed in the housing, the electronics circuit configured to generate and deliver pacing signals to the pacing electrode.   
     
     
         15 . The leadless implantable medical device of  claim 14 , further comprising a feedthrough assembly operatively connecting the fixation antenna to the electronic circuit. 
     
     
         16 . The leadless implantable medical device of  claim 14 , wherein the fixation antenna includes a body that extends between a proximal end and the distal end, the body having a length defined based on a wavelength of a carrier frequency for communication with the external device. 
     
     
         17 . The leadless implantable medical device of  claim 16 , wherein the length of the body is a quarter multiple of the wavelength of the carrier frequency. 
     
     
         18 . The leadless implantable medical device of  claim 16 , wherein the fixation antenna is shaped as a helix with less than five turns of rotation from the distal end to the proximal end. 
     
     
         19 . The leadless implantable medical device of  claim 16 , wherein the fixation antenna comprises less than one and a quarter turns of rotation from the distal end of the fixation antenna to the proximal end of the fixation antenna. 
     
     
         20 . The leadless implantable medical device of  claim 14 , wherein the fixation antenna has a body that is shaped as one of a helix, hook or straight needle.