Advanced pulse oximetry sensor

A method to determine a constituent or analyte in a patient's blood, the method comprising:

• emitting, from an emitter, light of a wavelength;
• spreading, with a diffuser, the emitted light and emitting the spread light from the diffuser to a tissue measurement site, wherein the diffuser spreads the light over a greater area of the tissue measurement site than would otherwise be illuminated by the emitter directly emitting light at a tissue measurement site;
• and
• detecting, with the detector, the emitted concentrated light.

A pulse oximeter sensor comprising:

• an emitter configured to emit light at a wavelength;
• a diffuser configured to receive the emitted light, to spread the received light, and to emit the spread light, wherein the emitted spread light is directed at a tissue measurement site;
• and
• a detector configured to detect the emitted spread light, the spread light having been attenuated by the tissue measurement site, the detector further configured to output a signal responsive to the detected light.

A pulse oximeter sensor comprising:

• an emitter configured to emit light at a wavelength;
• a concentrator which concentrates the emitted light after it has been attenuated by the tissue measurement site;
• and
• a detector configured to detect the emitted spread, the spread light having been attenuated by or reflected from the tissue measurement site, the detector further configured to output a signal responsive to the detected light.