Patent ID: 7570979

Claim:
A method of detecting disordered respiration in a patient, the method comprising: (a) exposing the patient's cerebral tissue to radiation, the radiation having at least first and second predetermined wavelengths, the first and second predetermined wavelengths being between about 730 nm to 770 nm, and 790 nm to 830 nm, respectively; (b) sensing the levels of radiation reflected by the cerebral tissue at the first and second predetermined wavelengths; (c) in a calibration step: (i) determining reflection levels for first and second patient orientations; and, (ii) using the determined reflection levels to determine a calibration factor; and (d) in a monitoring step: (i) calculating a blood oxygen index in accordance with the sensed reflected radiation and the calibration factor; and, (ii) detecting a presence or absence of disordered respiration in the patient based at least in part on changes in the blood oxygen index determined in accordance with the calibration factor.