Comparing of Frequency Components of Rest and Exercise-induced Three-Dimensional Magnetocardiogram

Abstract

Magnetocardiogram (MCG) is a non-invasive method for measuring functional information concerning the electrical activities of the heart. In this study, the exercise-induced MCG and body surface potential map (BSPM) were measured for normal subjects. MCG were measured by a three dimensional second-order gradiometer connected to 39-channel superconducting quantum interface device (SQUID), which can detect magnetic field components perpendicular to the chest wall (Bz) and tangential to the chest wall (Bx, By) simultaneously. Time-frequency analysis (wavelet analysis) was applied to the MCG to not examine the change of power spectrum of QRS complex and ST segment. We found that the frequency component of Bx, By, Bz in MCG with cross-correlation function was different. When I watch a temporal response of the frequency, 2-8Hz components showed a remarkable change. It is thought that frequency components may affect between rest time and after the exercise.