Patent ID: 7162288

Claim:
A pulse oximeter system comprising: a drive interface that controls drive current of light emitting elements in a pulse oximeter sensor; and a feedback loop coupled around the pulse oximeter sensor and the drive interface that dynamically adjusts the drive current of the light emitting elements based on results of a comparison between a signal-to-noise ratio of a pulse oximeter signal and a threshold, wherein the feedback loop comprises: a pulse detection block that calculates a moving average of a derivative of the pulse oximeter signal to generate a first output, calculates a moving average of the first output to generate a second output, calculates a moving average of the second output to generate a third output, and identifies a moving minimum and a moving maximum of the third output in order to determine the signal-to-noise ratio; and a comparator that performs the comparison of the signal-to-noise ratio of the pulse oximeter signal to the threshold, wherein the pulse oximeter signal is generated by a photodetector in the pulse oximeter sensor.