US Patent 9402545 Medical devices with proximity detection

A wireless medical device is disclosed. The wireless medical device comprises a processor, a memory, a sensor for detecting a physiological signal, a radio and a proximity detector to measure a distance of the wireless medical device relative to a second wireless medical device. The proximity detector includes a ranging functionality. A wireless communication channel is created when a distance between the wireless medical device and the second wireless medical device is within a first predetermined threshold. The distance is greater than zero.