A portable signal transfer unit for relaying a signal representative of physiological data of a mammalian subject from a remote physiological sensor to a remote receiver unit. The portable transfer unit includes an input device which operably receives the signal, a memory for buffering the signal, and an output device which wirelessly transmits the signal to the remote unit. The signal transfer unit also includes a signal processor for relaying the signal from the signal input to the output device, wherein the signal processor has two or more receivers each receiver adapted to handle a specified signal carrier frequency. An indicator is also provided which indicates to the subject whether the signal transfer unit is within range of the remote unit to enable effective transmission of the signal from the signal transfer unit to the remote unit.
