Abstract: A message waiting feature added to a PABX using the attendant's console and busy lamp field. The message waiting indication is provided by causing the busy lamp associated with the subscriber station that has the message waiting to blink.

Abstract: A supporting surface establishes a positional relationship between a sensor and an anatomical site which is to be monitored. The supporting surface may also act as an enclosure and as an acoustic baffle. An electronic circuit produces visible and audible output responsive to changes in a property of the sensor and therefore to changes in the physiological variable being monitored. The output may be used for physiological monitoring or for biofeedback training. The output format, the control placement, and the supporting surface make possible an improved biofeedback training method.