Parallel alarm processor

1. A parallel alarm processor comprising:

a sensor signal responsive to multiple wavelengths of light transmitted into a tissue site and detected after attenuation by pulsatile blood flow within the tissue site;

a first processor having an input responsive to the sensor signal and a smoothing output responsive to relatively long duration oxygen desaturations;

a second processor having an input responsive to the sensor signal and a predictor output responsive to relatively short duration, intermittent oxygen desaturations;

a threshold detector responsive to the smoothing output so as to generate a first alarm when the smoothing output crosses a predetermined threshold; and

a pattern processor responsive to the predictor output so as to generate a second alarm when a predetermined pattern is detected in a series of oxygen desaturations.

2. The parallel alarm processor according to claim 1 wherein the pattern processor comprises:

a pattern memory storing a predetermined reference pattern;

a pattern extractor generating an extracted pattern of oxygen desaturations from the predictor output; and

a comparator in communications with the pattern memory and the pattern extractor so as to trigger the second alarm when the reference pattern generally matches the extracted pattern.

3. The parallel alarm processor according to claim 2 wherein the first and second processors comprise a variable mode averager.

4. A parallel alarm processor method comprising: transmitting light having multiple wavelengths into a patient tissue site;

detecting the light after attenuation by pulsatile arterial blood flow within the tissue site so as to generate a sensor signal;

generating a first blood oxygen saturation measurement responsive to the sensor signal and to short duration, intermittent oxygen desaturations of the patient;

generating a second smoother blood oxygen saturation measurement responsive to the sensor signal and to long duration oxygen desaturations of the patient;

detecting a threshold crossing of the smoother blood oxygen saturation measurement;

recognizing a pattern in the first blood oxygen saturation measurement; and

triggering a first alarm in response to the recognized pattern and a second alarm in response to the threshold crossing.

5. The parallel alarm processor method according to claim 4 wherein generating a first blood oxygen saturation measurement comprises predicting an oxygen saturation parameter.

6. The parallel alarm processor method according to claim 5 wherein generating a second blood oxygen saturation measurement comprises smoothing an oxygen saturation parameter.

7. A parallel alarm processor comprising:

a threshold detector having a first output responsive to relatively long duration oxygen desaturations;

a pattern extractor having a second output responsive to relatively short duration oxygen desaturations;

a predetermined reference pattern indicative of a series of intermittent oxygen desaturations;

a first alarm triggered when the first output crosses a lower limit threshold; and

a second alarm triggered when the second output matches the predetermined reference pattern.

8. The parallel alarm processor according to claim 7 further comprising:

an integrator inputting smoothed oxygen saturation measurements to the threshold detector; and

a predictor inputting predictive oxygen saturation measurements to the pattern extractor.

9. The parallel alarm processor according to claim 8 wherein the integrator and the predictor are a variable mode averager.