Adaptive alarm system

An improved method of obtaining pulse oximetry measurements and reducing false alarms therefrom, the method comprising:

• continuously measuring, with a pulse oximeter in communication with an optical sensor, a physiological parameter over a first time window;
• establishing, with the pulse oximeter, a baseline for the physiological parameter, the parameter baseline being determined from values of the physiological parameter taken during a second window of time within the first time window, the baseline is reestablished using a new window of data on a continuing basis over the first time window;
• automatically determining, with the pulse oximeter, an upper alarm threshold and a lower alarm threshold at a delta difference from a most recent value of the baseline, the delta difference for the upper alarm threshold increases when the baseline drifts away from a maximum parameter limit and decreases when the baseline drifts toward the maximum parameter limit, the delta difference for the lower alarm threshold increases when the baseline drifts away from a minimum parameter limit and decreases when the baseline drifts toward the minimum parameter limit;
• dynamically adjusting, with the pulse oximeter, at predetermined regular intervals the delta difference between the alarm thresholds and the baseline during the first time window, the delta difference is adjusted based on a current value of the baseline, and the alarm thresholds are re-determined at the predetermined regular intervals over the first time window using the current delta difference;
• and
• triggering an alarm in response to the parameter measurement crossing either of the alarm thresholds.