Dual Microcomputer Analysis of Cardiac Transmembrane Action Potentials

A dual microcomputer system has been developed for automating the analysis of cardiac transmembrane action potentials. This system consists of two microcomputers and supporting function modules which digitize, detect, analyze, and plot the transmembrane action potentials from a cardiac cell impaled with a microelectrode. The action potentials are digitized at two sampling rates for computer processing; a sampling rate of 10 kHz is used to obtain the rapid initial upstroke, while a rate of 100 Hz is used to obtain the slower repolarization phase. The action potentials are characterized by graphic displays using the derived measurements. The system measures the resting potential, overshoot amplitude, dV/dtmax and time for 50, 70, and 95 percent repolarization of the action potential.