Heart frequency monitor of two-level detecting type, converts amplified impedance signal into rectangular wave and determines average frequency of peaks

摘要

The monitor includes two conductive contacts for contacting with the two hands or feet of a person. An amplifier/filter circuit detects an impedance signal between the contacts, to amplifier the pulse of the signal and remove noise. A waveform converter converts the output from the amplifier/filter circuit into a rectangular wave. A processing circuit determines the average frequency of the peaks of the rectangular signal using a computer-assisted process, and the result is indicated on a display.