摘要 |
<p>A system and method, for measuring phase delay and amplitude of a near infrared signal emanating from tissue of an animal subject in response a near infrared signal input to such tissue, operate by processing a signal from an optical detector and a corresponding signal from an optical detector emulation circuit. In some aspects, the processed signals are fed into zero crossing detectors that in turn feed a time-to-digital converter providing at an output thereof a digital measure of the phase delay of the received optical signal.</p> |