Patent ID: 7221969

Claim:
Apparatus for spectrophotometrically monitoring hemoglobin oxygenation in a test subject, comprising in combination: a source of photons having a desired wavelength; a probe coupled to said source to optically access a single location on the test subject by injecting photons into said subject from said source at said location and for receiving photons exiting said subject at said location after injection; a photon-conducting device operatively associated with said probe to receive a stream of said exiting photons and to produce at least two differently timed streams of photons therefrom; a shuttered device coupled to said photon-conducting device to receive said at least two differently-timed photon streams and simultaneously switch each of said two streams on and off to create a pair of different photon bursts therefrom; and a detector coupled to said shutter device to receive said pair of separate photon bursts and provide corresponding output signals for processing.