title: Optimal Magnetic Sensor Vests for Cardiac Source Imaging.
abstract: Magnetocardiography (MCG) non-invasively provides functional information about the heart. New room-temperature magnetic field sensors, specifically magnetoresistive and optically pumped magnetometers, have reached sensitivities in the ultra-low range of cardiac fields while allowing for free placement around the human torso. Our aim is to optimize positions and orientations of such magnetic sensors in a vest-like arrangement for robust reconstruction of the electric current distributions in the heart. We optimized a set of 32 sensors on the surface of a torso model with respect to a 13-dipole cardiac source model under noise-free conditions. The reconstruction robustness was estimated by the condition of the lead field matrix. Optimization improved the condition of the lead field matrix by approximately two orders of magnitude compared to a regular array at the front of the torso. Optimized setups exhibited distributions of sensors over the whole torso with denser sampling above the heart at the front and back of the torso. Sensors close to the heart were arranged predominantly tangential to the body surface. The optimized sensor setup could facilitate the definition of a standard for sensor placement in MCG and the development of a wearable MCG vest for clinical diagnostics.
authors.affiliation: Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany. stephan.lau@tu-ilmenau.de.|Biomagnetic Center, Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany. stephan.lau@tu-ilmenau.de.|NeuroEngineering Laboratory, Department of Electrical and Electronic Engineering, The University of Melbourne, 3010 Parkville, Australia. stephan.lau@tu-ilmenau.de.
authors.forename: Stephan
authors.initials: S
authors.lastname: Lau
authors.affiliation: Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany. bojana.petkovic@tu-ilmenau.de.
authors.forename: Bojana
authors.initials: B
authors.lastname: Petković
authors.affiliation: Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany. jens.haueisen@tu-ilmenau.de.|Biomagnetic Center, Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany. jens.haueisen@tu-ilmenau.de.
authors.forename: Jens
authors.initials: J
authors.lastname: Haueisen
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D002318:Cardiovascular Diseases / Q000000981:diagnostic imaging; D006801:Humans; D008280:Magnetics; D053798:Magnetocardiography / Q000379:methods*
keywords: boundary element method; cardiovascular diseases; heart; inverse problems; magnetocardiography (MCG); magnetostatics; matrix condition; particle swarm optimization; source analysis; wearable multi-sensor systems