Signal processing apparatus

A physiological monitor comprising:

• a detector to provide intensity signals resulting from light of first and second wavelengths attenuated by body tissue carrying pulsing blood, each intensity signal containing a primary signal portion and a secondary signal portion, said intensity signals adhering to a predefined signal model;
• and
• a signal processor coupled to said detector, said signal processor receiving said intensity signals, transforming said signals, identifying a plurality of peaks of magnitudes from the transformed signals, and applying a plurality of rules to the peaks of magnitudes in order to calculate at least two estimates for said oxygen saturation.

A physiological monitor comprising:

• a detector to provide intensity signals resulting from light of first and second wavelengths attenuated by body tissue carrying pulsing blood, each intensity signal containing a primary signal portion and a secondary signal portion, said intensity signals adhering to a predefined signal model;
• and
• a signal processor coupled to said detector, said signal processor receiving said intensity signals, Fourier transforming said signals, identifying a plurality of peaks of magnitudes from the Fourier transformed signals, and applying a plurality of rules to the peaks of magnitudes in order to determine an estimate for said oxygen saturation, wherein said signal processor comprises a neural network.

A physiological monitor comprising:

• a detector to provide intensity signals resulting from light of first and second wavelengths attenuated by body tissue carrying pulsing blood, each intensity signal containing a primary signal portion and a secondary signal portion, said intensity signals adhering to a predefined signal model;
• and
• a signal processor coupled to said detector, said signal processor receiving said intensity signals, Fourier transforming said signals, identifying a plurality of peaks of magnitudes from the Fourier transformed signals, and applying a plurality of rules to the peaks of magnitudes in order to determine an estimate for said oxygen saturation, wherein the plurality of rules comprises analysis of a phase from the Fourier transformed signals.