Low-power radio telemetry: the potential for remote patient monitoring

Radio-based signalling devices will play an important role in future generations of remote patient monitoring equipment, both at home and in hospital. Ultimately, it will be possible to sample vital signs from patients, whatever their location and without them necessarily being aware that a measurement is being taken. This paper reviews current methods for the transmission by radio of physiological parameters over ranges of 0.3, 3 and 30 m, and describes the radiofrequency hardware required and the carrier frequencies commonly used. Future developments, including full duplex systems and the use of more advanced modulation schemes, are described. The paper concludes with a case study of a human temperature telemeter built to indicate ovulation. Clinical results clearly show the advantage to be had in adopting radio biotelemetry in this instance.