Non-contact measurement of cardiac electromagnetic field in mice by use of a microfabricated atomic magnetometer

The development of clinical applications of magnetocardiography has been impeded by the large size of the systems used to measure magnetic fields. Here we present the first measurements of the cardiac electromagnetic field with a highly miniaturized (20 mm
³
), atomic magnetometer constructed by microfabrication techniques. Measurements were performed in two mice. The magnetometer was placed close to the sternum region, approximately 2 mm away from the surface of the skin. QRS complexes were identifiable in the magnetocardiographic signals in all recordings except for those performed when the animal was moved far away (>10 cm) from the sensor. Non-contact recording of cardiac electromagnetic fields with a microfabricated magnetometer is feasible in a shielded environment.