A living tissue light transmission simulator system (208, 308) includes receptors of light (215, 216, 315, 316) in portions of the infrared and red spectral bands and the receptors (215, 216, 315, 316), together with amplification (217, 218, 317, 318), infrared detection (239, 371), spectral separation circuitry (219, 319), and post-separation amplification (220, 221, 338, 339, 340, 320, 321), that may be used to drive at least one light source (222, 223, 322, 361). The living tissue light transmission simulator system (208, 308) includes at least one shutter (225, 235, 324, 363, 450) to mechanically modulate generated light from the at least one driven light source (222, 223, 322, 361) where the modulated light may be directed to a pulse oximeter.