detecting, by the implantable device, failure to receive {TAIL ~ a response communication} from the external device within {HEAD ~ a specified maximum response time value} 
detecting , by the implantable device , failure to receive { TAIL ~ a response communication } from the external device within { HEAD ~ a specified maximum response time value }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD