Pulse transducer with artifact signal attenuator

摘要

In combination with a pulse transducer characterized by a source of light and a detector for light reflected from blood vessels of a living body, to provide heart signal consisting of a modulated dc signal voltage indicative of the pulse rate for the body, an artifact signal resulting from a reflection of light from the skin of the body, which includes both a constant dc signal component and a modulated dc signal component the amplitude of which is greater and the frequency of which is less than said heart signal, a signal attenuator circuit including an operational amplifier for canceling said artifact signal from the output signal of the pulse transducer.