Abstract

A patient vital signs monitoring system includes an elongated flexible esophageal stethoscope catheter including a microphone and a thermister measuring means detachably connected to a processing monitor through a patient interface unit for electrical isolation of the patient from the processing system to assure patient safety from electrical currents. A single microphone, including an amplifier, picks up and transmits sound from the stethoscope catheter through a processing system including an audio filter system in the patient interface unit which amplifies the heartbeat and breathing sounds and transmits signals to the monitor/transmitter unit through a fiberoptic link to the microprocessor where the signals are compared against reference limits for generating alarm signals in response to critical deviations from preset norm. The monitor/transmitter unit is programmed to be self-monitoring prior to going into the normal patient monitoring mode and while in the monitoring mode. An IR transmitter in the monitor/transmitter unit transmits the vital breath and heart sounds by way of an infrared signal which is received by a portable receiver carried by the operator and monitored by an earphone to eliminate interference from electrical systems and avoiding additional hardline electrical connections within the operating room.

Other References

• Linnarsson et al, "Oesophageal Probe . . . ", Med & Biol. Eng & Comp., 1982