Electrocardiography (ECG) is one of the most widely used methods in clinical diagnosis. Here we describe an experimental approach that offers hands-on learning of its basic principles. An experimental model that consists of a rubber foil with a low electrical conductivity and a DC power unit is used to simulate the body and the electric dipole of the heart. It enables students to learn about the main features of the electric dipole and to visualize the induced electric potential in the body. The determination of the characteristic equipotential lines around the dipole and the measurement of simple electrocardiograms, comprising bipolar and unipolar leads, are made with a low-cost voltmeter. To make the exercise more relevant to clinical ECG, as well as making it more interesting, the students are additionally tasked to measure their own electrocardiogram with a simple, personal handheld ECG device.
Keywords: basic principles; electric dipole; electrocardiography; equipotential lines; teaching.