An Electronc Circuit for Red/Infrared Oximeters
Eugen G. Schibli, Sinclair S. Yee, Vedavalli M. Krishnan · IEEE Transactions on Biomedical Engineering · 1978
An inexpensive electronic circuit is described for operation of a red/infrared oximeter that does not use fiberoptics. The circuit provides low-evel amplitude modulation of the LED currents. Narrow-band detectors separate the backscattered signal into the red and infrared components. An AGC loop performs the division (Ei/Er).