Monitoring heart and breath sounds by telemetry

A system for FM radiotelemetry of heart and breath sounds is described. Patients' heart and breath sounds are detected by oesophageal or precordial stethoscopes. The anaesthetist, carrying a portable radio receiver, is then free to move around theatre while listening to these sounds through headphones or an ear-piece. The FM telemetry system has also been used to assist patient monitoring in noisy environments such as ambulances.