#$%^&*AU2010227077B220111103.pdf#####ABSTRACT An apparatus for non-invasively determining a blood oxygen saturation level of the microcirculation within a subjects tissue, having at least one spectrophotometric sensor having at least one light source and at least one light detector, wherein the light source is operable to transmit light along a plurality of wavelengths into the subjects tissue, and the light detector is operable to detect light from the light source after the light has travelled through the subjects tissue, and the sensor is operable to produce signal data attributable to non-pulsatile blood flow within the microcirculation of the subjects tissue from the detected light and a processor operably connected to the at least one sensor, the processor having an algorithm operable to process the signal data to account for the physical characteristics of the subjects tissue. 1/
