The personal website of Scott W Harden

ECG Simulator Circuit

This page describes a simple circuit which produces ECG-like waveform. The waveform is not very detailed, but it contains a sharp depolarizing (rising) component, a slower hyperpolarizing (falling) component, and a repetition rate of approximately one beat per second making it potentially useful for testing heartbeat detection circuitry.

In 2019 I released a YouTube video and blog post showing how to build an ECG machine using an AD8232 interfaced to a computer’s sound card. At the end of the video I discussed how to use a 555 timer to create a waveform roughly like an ECG signal, but I didn’t post the circuit at the end of that video. I get questions about it from time to time, so I’ll share my best guess at what that circuit was here using LTSpice to simulate it.

Design Notes