A low-cost microcomputer system for automated analysis of intracellular cardiac action potentials

A microcomputer system for automated analysis of action potentials recorded from cardiac Purkinje fibers is described. The system is based upon a DMD 800 microcomputer built around a Z80 microprocessor. Two different sampling intervals are used for analog-to-digital conversion of action potential recorded from driven fibers. The following parameters can be obtained on-line: action potential amplitude; overshoot; maximum diastolic potential; action potential duration measured both at -60 mV and at 90% of complete repolarization; and maximum rate of rise of the upstroke. The digitized form of five consecutive action potentials can be stored on a floppy disk. The automated system eliminates hand measurements; the on-line analysis of the action potentials during pharmacological interventions allows a rapid appreciation of drug effects.