Electrical effects of a highly conductive mass inside the thorax

Abstract

Model experiments were conducted using an artificial dipole to determine the effect of the volume of a highly conducting mass (such as the heart) inside a finite volume conductor (such as the body) on the dipole moment obtained from integrals of body surface potentials, and on the boundary potential distribution. In one series of experiments, a dog's urinary bladder filled with fluid of conductivity similar to that of the blood, was placed in a tank having the shape of the human thorax and filled with fluid of conductivity similar to that of the tissues. An electric dipole was placed in direct contact with the bladder, and the effect of varying the volume and the position of the bladder on the boundary potential distribution was studied. It was found that the surface potentials depended greatly on the position and the volume of the bladder. In another series of experiments, the effect of the volume of the bladder on the magnitude of the dipole moment was studied. The results showed that the physical presence of the bladder and the volume of the bladder had a definite effect on the magnitude of the resultant dipole moment. Two empirical equations, describing this effect, were derived.