Abstract: Several techniques are provided for aiding in the discrimination of detected biological signals indicative of blood pressure from detected signals not indicative of blood pressure (e.g., noise). In one technique, mixed signals which include biological signals indicative of blood pressure and noise signals not indicative of blood pressure are detected during time periods, and are evaluated over a plurality of the time periods to aid in discriminating the biological signals from the noise signals. This enhances the signal-to-noise ratio of the biological signals. In a related technique, the mixed signals are analyzed in different ways based on whether the noise level exceeds a threshold to discriminate the biological signals from the noise signals. Still another technique includes determining whether a candidate blood pressure signal should be used to measure blood pressure based on whether it exceeds a plurality of different thresholds.

Abstract: A calibration method and apparatus capable of being calibrated according to the method that allows a remote sensor to be transferred from analyzing instrument to analyzing instrument within a group of analyzing instruments without the need to recalibrate. The device includes a separate memory capability associated with the sensor as well as each instrument while the method requires the use of an arbitrarily selected sensor to initially be transferred from instrument to instrument, while being subjected to the same calibration standards in order to generate calibration data for entry into each instrument's memory. With such data entered in the instruments' memories, any remote sensor, calibrated on any one instrument and having such calibration data stored in its own memory, can then readily be interconnected to any instrument of the group to immediately yield accurate results.