Noninvasive magnetic detection of cardiac mechanical activity: Experiments

Publisher Website
Google Scholar
Abstract
The magnetic susceptibility of the heart and the intracardiac blood is substantially greater than that of the surrounding lung tissue. The periodic redistribution of blood and tissue during the cardiac cycle will alter an externally applied magnetic field. These magnetic field changes can be detected by a magnetometer outside the [human] body, and were termed magnetic susceptibility plethysmography (MSPG) signals. A differential magnetometer, a liquid helium dewar and a superconducting persistent-current magnet were developed to detect the x component of the MSPG signal. The theoretical analysis of this instrument is presented to understand the spatial sensitivity of an MSPG susceptometer with a nonuniform magnetizing field. Preliminary measurements are in fair agreement with the model calculations. Several possible improvements of the technique are discussed.

This publication has 2 references indexed in Scilit: