Digital Cardiac Period Meter With DA Converter


Address requests for reprints to: H. Shimizu, Center of Educational Technology, Aichi Educational College, Kariya-Shi Aichi-Ken, Japan.


A new type of cardiac period meter, which allows the simultaneous collection of digital and analog records, was designed. The wave-shaper and the pulse sequencer in a digital counter were modified for the purpose of measuring successive heartbeat intervals. The output terminals of the counter were connected directly to a digital-to-analog (DA) converter. The pen-oscillograph record of the analog output produces a stair-case waveform characterized by sharp edges and stable horizontal lines.