Disclosed systems and methods include electronic devices attached to a patient or object that transmit data to other devices over a secure communication channel. The devices can track and/or monitor object(s) and/or patient(s) and transmit the tracked and/or monitored data to other electronic devices. Such data can include monitored patient physiological parameter(s) received and/or sensed by the device, for example. A master of the two devices transmits a communication signal to another device that, in response, initiates a secure wireless communication channel, causes one or more modules on the device to be powered, and, when powered, transmits the tracked and/or sensed physiological data over the secure wireless communication channel to the master device. Some example master devices transmit the communication signal with an instruction to the device to activate an onboard power source that later may be disconnected after the tracked and/or physiological data is transmitted.