Mapping of Human Heart Beat Dynamics by Atomic Magnetometers

摘要

Stimulated by recent progress in laser-based optical magnetometry and in developments of powerful signal denoising techniques we initiated the development of a low-cost laser-driven optically pumped magnetometer (OPM) for biomagnetic applications. The OPM uses optically pumped cesium atoms in glass cells of a few cm3. Its sensitivity (<70 fT in 1 Hz bandwidth), bandwidth (140 Hz), and spatial resolution (cm) were optimized for the two-dimensional mapping of the magnetic field produced above the chest by the beating human heart. Signal averaging using an electrocardiographic signal as a reference and gradiometric detection reduces residual noise significantly so that the dynamics of the heart field can be displayed a movie. We discuss the principle of the technique and give a status report on ongoing work towards the development of a multichannel device.