Comparison of Magnetocardiographic Mapping with SQUID-based and Laser-pumped Magnetometers in Normal Subjects

From the point of view of the average clinician, an ideal instrument for magnetocardiographic mapping (MCG) should be multichannel, easy to operate and maintainance-free, low cost, and reliable at patient bedside. Presently available systems for multichannel magnetocardiography are based on SQUID technology, which is expensive and implies the additional difficulty and cost of continuous system refrigeration with liquid helium. Also HT-SQUID technology, which would at least cut the cost of refrigeration, although rapidly progressing, is still very expensive. Recently, interesting results have been reported with a novel single-channel optical-pumping magnetometer (OPM) [1,2], which technology could simplify most of the above mentioned problems. However so far preliminary measurementes with the OPM were carried out in a non clinical environment Therefore it was necessary to validate their quality and reproducibility through comparison with recordings carried out in the same subjects with a multichannel MCG system designed for clinical use in an unshielded hospital environment. This has been the aim of our cooperative pilot study, which preliminary results are reported here.