School of Physics Lecture Demonstration Manual

Ej-1 Rotating Dipole Analogue of the Electrocardiograph

Published: Tuesday 14 March 2006 - Updated: Tuesday 29 March 2011


To demonstrate a simple model of the electrocardiograph.



Click on pictures to enlarge.

Analogue ECG Diagram


A potential difference occurs across the heart during its operation. The complex rhythmic potentials can be picked up by suitably placed electrodes on the body to obtain an E.C.G.

To simulate this a battery is placed in a conducting salt water solution. Two electrodes in the container are connected to a galvanometer. Rotating the battery causes the galvanometer deflection to vary sinusoidally.

The heart is being represented by a rotating dipole. The salt solution represents the conducting electrolyte of the body.

Safety notes

Electrical safety 

Sharps safety 


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