Principles of Device Operation

Ionic (cellular) currents of the heart muscle generate local magnetic fields, which the CMI Magnetocardiograph can measure with astounding accuracy, when placed close to, but not touching, the torso. These same currents generate electric potential differences on the patient’s body surface, which are measured by conventional electrocardiography. Not surprisingly, and as we will see later, the temporal trace of a local magnetic field (the magnetocardiographic trace) is similar and analogous to an EKG trace.

Here is an image showing the position of the nine CMI sensors (shown outside of their housing) which measure the magnetic field above the patient. The device does not emanate any magnetic field or harmful radiation.

Contrast this with the picture shown below illustrating the typical attachment of EKG leads to a patient.