1. A medical device, comprising: a wireless radio frequency digital communication transceiver adapted for local communications; a physiological interface adapted to communicate medical prognostic, diagnostic or therapeutic information, by at least one of receiving a physiological signal, producing a physiological stimulation, producing a motion or displacement, infusing a drug, and acquiring a biological sample; and at least one programmable automated electronic processor within the medical device, configured to: communicate through the wireless radio frequency digital communication transceiver to a proximate relay device external to the medical device; control the relay device to communicate with a plurality of remote servers, the relay device being configured to establish a secure communication tunnel between the medical device and a selected one of a plurality of different endpoints through a public network, the plurality of different endpoints each being associated with a respective public key infrastructure security certificate; receive a request for opening a communication channel with a respective endpoint based on a message received through the wireless radio frequency digital communication transceiver from the relay device; verify the received request based on communications through the relay device, by receiving a respective security certificate associated with the respective endpoint, verifying a public key associated with the respective security certificate, and checking a certificate revocation list for presence of the security certificate; after verifying the received request, establish the secure communication tunnel between the medical device and the respective endpoint according to the verified security certificate; and communicate the medical prognostic, diagnostic or therapeutic information through the secure communication tunnel.