{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T14:51:14Z","timestamp":1781880674713,"version":"3.54.5"},"reference-count":80,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2016,5,24]],"date-time":"2016-05-24T00:00:00Z","timestamp":1464048000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"German Research Council","award":["GK 1567-C4"],"award-info":[{"award-number":["GK 1567-C4"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>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.<\/jats:p>","DOI":"10.3390\/s16060754","type":"journal-article","created":{"date-parts":[[2016,5,24]],"date-time":"2016-05-24T21:53:40Z","timestamp":1464126820000},"page":"754","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Optimal Magnetic Sensor Vests for Cardiac Source Imaging"],"prefix":"10.3390","volume":"16","author":[{"given":"Stephan","family":"Lau","sequence":"first","affiliation":[{"name":"Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany"},{"name":"Biomagnetic Center, Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany"},{"name":"NeuroEngineering Laboratory, Department of Electrical and Electronic Engineering, The University of Melbourne, 3010 Parkville, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bojana","family":"Petkovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jens","family":"Haueisen","sequence":"additional","affiliation":[{"name":"Institute of Biomedical Engineering and Informatics, Ilmenau University of Technology, P.O. Box 100565, D-98684 Ilmenau, Germany"},{"name":"Biomagnetic Center, Department of Neurology, Jena University Hospital, Erlanger Allee 101, D-07747 Jena, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2016,5,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Leder, U., Haueisen, J., Huck, M., and Nowak, H. (1998). Non-invasive imaging of arrhytmogenic left-ventricular myocardium after infarction. Lancet, 352.","DOI":"10.1016\/S0140-6736(98)00082-8"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Andr\u00e4, W., and Nowak, H. (2006). Magnetism in Medicine: A Handbook, Wiley. [2nd ed.].","DOI":"10.1002\/9783527610174"},{"key":"ref_3","unstructured":"D\u00f6ssel, O. Inverse Problem of Electro- and Magnetocardiography: Review and Recent Progress. Available online: http:\/\/www.ijbem.org\/volume2\/number2\/doessel\/paper_ijbem.htm."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Freitas, P.P., Ferreira, R., Cardoso, S., and Cardoso, F. (2007). Magnetoresistive sensors. J. Phys. Condens. Matter, 19.","DOI":"10.1088\/0953-8984\/19\/16\/165221"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"3273","DOI":"10.1103\/PhysRevLett.74.3273","article-title":"Large magnetoresistance at room temperature in ferromagnetic thin film tunnel junctions","volume":"74","author":"Moodera","year":"1995","journal-title":"Phys. Rev. Let."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"17E501","DOI":"10.1063\/1.4859036","article-title":"Room temperature direct detection of low frequency magnetic fields in the 100 pT\/Hz1\/2 range using large arrays of magnetic tunnel junctions","volume":"115","author":"Paz","year":"2014","journal-title":"J. App. Phys."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Cardoso, S., Gameiro, L., Leitao, D.C., Cardoso, F., Ferreira, R., Paz, E., and Freitas, P.P. (2013, January 24\u201326). Magnetic tunnel junction sensors with pTesla sensitivity for biomedical imaging. Proceedings of the SPIE Smart Sensors, Actuators, and MEMS VI, Grenoble, France.","DOI":"10.1117\/12.2018070"},{"key":"ref_8","first-page":"08B317","article-title":"Progress toward a thousandfold reduction in 1\/f noise in magnetic sensors using an AC microelectromechanical system flux concentrator","volume":"99","author":"Edelstein","year":"2006","journal-title":"Appl. Phys. Lett."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Bison, G., Castagna, N., Hofer, A., Knowles, P., Schenker, J.L., Kasprzak, M., Saudan, H., and Weis, A. (2009). A room temperature 19-channel magnetic field mapping device for cardiac signals. Appl. Phys. Lett., 95.","DOI":"10.1063\/1.3255041"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1038\/nphys566","article-title":"Optical magnetometry","volume":"3","author":"Budker","year":"2007","journal-title":"Nat. Phys."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"981","DOI":"10.1364\/BOE.3.000981","article-title":"Magnetoencephalography with a chip-scale atomic magnetometer","volume":"3","author":"Sander","year":"2012","journal-title":"Biomed. Opt. Express"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"14201","DOI":"10.1364\/OE.20.014201","article-title":"Characteristics and performance of an intensity-modulated optically pumped magnetometer in comparison to the classical MX magnetometer","volume":"20","author":"Schultze","year":"2012","journal-title":"Opt. Express"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1051\/epn\/2012301","article-title":"Optically pumped alkali magnetometers for biomedical applications","volume":"43","author":"Weis","year":"2012","journal-title":"Europhys. News"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Yin, X.L., Liu, Y.F., Ewing, D., Ruder, C.K., De Rego, P.J., Edelstein, A.S., and Liou, S.H. (2015, January 9\u201313). Tuning magnetic nanostructures and flux concentrators for magnetoresistive sensors. Proceedings of the SPIE 9551 Spintronics VIII, San Diego, CA, USA.","DOI":"10.1117\/12.2188712"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3306","DOI":"10.1109\/TMAG.2006.879752","article-title":"Magnetic-field dependence of the noise in a magnetoresistive sensor having MEMS flux concentrators","volume":"42","author":"Ozbay","year":"2006","journal-title":"IEEE Trans. Magn."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Guo, Y., Wang, J., White, R.M., and Wang, S.X. (2015). Reduction of magnetic 1\/f noise in miniature anisotropic magnetoresistive sensors. Appl. Phys. Lett., 106.","DOI":"10.1063\/1.4921764"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Wang, Y., Li, J., and Viehland, D. (2015). A differential magnetoelectric heterostructure: Internal noise reduction and external noise cancellation. J. Appl. Phys., 118.","DOI":"10.1063\/1.4936263"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Valadeiro, J.P., Amaral, J., Leit\u00e3o, D.C., Ferreira, R., Freitas Cardoso, S., and Freitas, P.J.P. (2015). Strategies for pTesla field detection using magnetoresistive sensors with a soft pinned sensing layer. IEEE Trans. Magn., 51.","DOI":"10.1109\/TMAG.2014.2352115"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Edelstein, A., Fischer, G.A., Burnette, J.E., Egelhoff, W.E., and Cheng, S.F. (2009, January 25\u201328). Achieving 1\/f noise reduction with the MEMS flux concentrator. Proceedings of the 2009 IEEE Sensors, Christchurch, New Zealand.","DOI":"10.1109\/ICSENS.2009.5398411"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Liou, S.H., Sellmyer, D., Russek, S.E., Heindl, R., Da Silva, F.C.S., Moreland, J., and Pappas, D.P. (2009, January 25\u201328). Magnetic noise in a low-power picotesla magnetoresistive sensor. Proceedings of the 2009 IEEE Sensors, Christchurch, New Zealand.","DOI":"10.1109\/ICSENS.2009.5398414"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Fischer, G.A., and Edelstein, A.S. (2010, January 1\u20134). Magnetic modeling of a MEMS flux concentrator. Proceedings of the 2010 IEEE Sensors, Kona, HI, USA.","DOI":"10.1109\/ICSENS.2010.5690690"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Hu, J., Pan, M., Tian, W., Chen, D., and Luo, F. (2012). Integrating magnetoresistive sensors with microelectromechanical systems for noise reduction. Appl. Phys. Lett., 101.","DOI":"10.1063\/1.4769903"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"793","DOI":"10.1007\/s00542-013-2035-1","article-title":"Magnetic tunnel junction sensors with pTesla sensitivity","volume":"20","author":"Cardoso","year":"2014","journal-title":"Microsyst. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Tian, W., Hu, J., Pan, M., Chen, D., and Zhao, J. (2016). Magnetic flux vertical motion modulation for 1\/f noise suppression in magnetoresistance field sensors using MEMS device. IEEE Trans. Magn., 52.","DOI":"10.1109\/TMAG.2013.2264061"},{"key":"ref_25","unstructured":"Multi Dimension TMR9001 Linear Sensor, Datasheet. Available online: http:\/\/www.dowaytech.com\/en\/1866.html."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Yin, X., and Liou, S.H. (2012, January 28\u201331). Novel magnetic nanostructured multilayer for high sensitive magnetoresistive sensor. Proceedings of the 2012 IEEE Sensors, Taipei, Taiwan.","DOI":"10.1109\/ICSENS.2012.6411027"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Supek, S., and Aine, C.J. (2014). Magnetoencephalography, Springer.","DOI":"10.1007\/978-3-642-33045-2"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"27167","DOI":"10.1364\/OE.18.027167","article-title":"Femtotesla atomic magnetometry in a microfabricated vapor cell","volume":"18","author":"Griffith","year":"2010","journal-title":"Opt. Express"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Knappe, S., Sander, T.H., Kosch, O., Wiekhorst, F., Kitching, J., and Trahms, L. (2010). Cross-validation of microfabricated atomic magnetometers with superconducting quantum interference devices for biomagnetic applications. Appl. Phys. Lett., 97.","DOI":"10.1063\/1.3491548"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"2247","DOI":"10.1364\/OL.37.002247","article-title":"Optical magnetometer array for fetal magnetocardiography","volume":"37","author":"Wyllie","year":"2012","journal-title":"Opt. Lett."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"8153","DOI":"10.1088\/0031-9155\/58\/22\/8153","article-title":"A compact, high performance atomic magnetometer for biomedical applications","volume":"58","author":"Shah","year":"2013","journal-title":"Phys. Med. Biol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"876","DOI":"10.1364\/BOE.5.000876","article-title":"Optical multichannel room temperature magnetic field imaging system for clinical application","volume":"5","author":"Lembke","year":"2014","journal-title":"Biomed. Opt. Express"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4797","DOI":"10.1088\/0031-9155\/60\/12\/4797","article-title":"Fetal magnetocardiography measurements with an array of microfabricated optically pumped magnetometers","volume":"60","author":"Alem","year":"2015","journal-title":"Phys. Med. Biol."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Dang, H.B., Maloof, A.C., and Romalis, M.V. (2010). Ultrahigh sensitivity magnetic field and magnetization measurements with an atomic magnetometer. Appl. Phys. Lett., 97.","DOI":"10.1063\/1.3491215"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Kamada, K., Taue, S., and Kobayashi, T. (2011). Optimization of bandwidth and signal responses of optically pumped atomic magnetometers for biomagnetic applications. Jpn. J. Appl. Phys., 50.","DOI":"10.7567\/JJAP.50.056602"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"6976","DOI":"10.1364\/OE.23.006976","article-title":"Noise reduction and signal-to-noise ratio improvement of atomic magnetometers with optical gradiometer configurations","volume":"23","author":"Kamada","year":"2015","journal-title":"Opt. Express"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1108\/03321640710727719","article-title":"Numerical comparison of sensor arrays for magnetostatic linear inverse problems based on a projection method","volume":"26","author":"Haueisen","year":"2007","journal-title":"COMPEL"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"5085","DOI":"10.1063\/1.1146524","article-title":"Multichannel SQUID system detecting tangential components of the cardiac magnetic field","volume":"66","author":"Tsukada","year":"1995","journal-title":"Rev. Sci. Instrum."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"631","DOI":"10.1109\/TMAG.2004.824891","article-title":"Information content in single-component versus three component cardio-magnetic fields","volume":"40","author":"Arturi","year":"2004","journal-title":"IEEE Trans. Magn."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"869","DOI":"10.1108\/03321640510598193","article-title":"Three component magnetic field data: Impact on minimum norm solutions in a biomedical application","volume":"24","author":"Haueisen","year":"2005","journal-title":"COMPEL"},{"key":"ref_41","unstructured":"Schnabel, A., Burghoff, M., Hartwig, S., Petsche, F., Steinhoff, U., Drung, D., and Koch, H. (2004). A sensor configuration for a 304 SQUID vector magnetometer. Neurol. Clin. Neurophys., 1, PMID 16012698."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"3444","DOI":"10.3938\/jkps.53.3444","article-title":"Performance investigation of a three-dimensional SQUID magnetocardiography system by using a computer simulation","volume":"53","author":"Kang","year":"2008","journal-title":"J. Korean Phys. Soc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1109\/TBME.1978.326332","article-title":"Limited lead selection for estimation of body-surface potential maps in electrocardiography","volume":"25","author":"Lux","year":"1978","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"186","DOI":"10.1161\/01.RES.49.1.186","article-title":"Redundancy reduction for improved display and analysis of body-surface potential maps \u2160. Spatial compression","volume":"49","author":"Lux","year":"1981","journal-title":"Circ. Res."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"125","DOI":"10.1109\/TBME.1971.4502813","article-title":"Selection of the number and position of measuring locations for electrocardiography","volume":"18","author":"Barr","year":"1971","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Finlay, D.D., Nugent, C.D., Donnelly, M.P., Lux, R.L., McCullagh, P.J., and Black, N.D. (2006). Selection of optimal recording sited for limited lead body surface potential mapping: A sequential selection based approach. BMC Med. Inform. Decis. Mak., 6.","DOI":"10.1186\/1472-6947-6-9"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"852","DOI":"10.1016\/0002-9149(85)90768-4","article-title":"Identification of best electrocardiographic leads for diagnosing myocardial infarction by statistical analysis of body surface potential maps","volume":"56","author":"Kornreich","year":"1985","journal-title":"Am. J. Cardiol."},{"key":"ref_48","unstructured":"D\u00f6ssel, O., Schneider, F., and M\u00fcller, M. (November, January 29). Optimization of electrode positions for multichannel electrocardiography with respect to electrical imaging of the heart. Proceedings of the 20th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, Hong Kong, China."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"257","DOI":"10.1016\/j.jelectrocard.2008.02.004","article-title":"Lead selection: Old and new methods for locating the most electrocardiogram information","volume":"41","author":"Donnelly","year":"2008","journal-title":"J. Electrocardiol."},{"key":"ref_50","first-page":"174","article-title":"Selection of optimal recording sites in electrocardiography and magnetocardiography","volume":"48","author":"Burghoff","year":"2004","journal-title":"Biomed. Eng. Biomed. Te."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1016\/j.ics.2007.01.060","article-title":"Influence of limited lead selection on source localization in magnetocardiography and electrocardiography","volume":"1300","author":"Hren","year":"2007","journal-title":"Int. Congr. Ser."},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"254","DOI":"10.1016\/S0921-4534(02)00683-4","article-title":"Comparison of sensor arrangements of MCG and ECG with respect to information content","volume":"372\u2013376","author":"Nalbach","year":"2002","journal-title":"Physica. C Supercond."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"1442","DOI":"10.1109\/TMAG.2007.915911","article-title":"Tabu search optimization of magnetic sensor systems for magnetocardiography","volume":"44","author":"Lau","year":"2008","journal-title":"IEEE Trans. Magn."},{"key":"ref_54","unstructured":"Golub, G.H., and Loan, C.F.V. (1996). Matrix Computations, John Hopkins University Press."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1145\/322139.322148","article-title":"Scaling for numerical stability in Gaussian elimination","volume":"26","author":"Skeel","year":"1979","journal-title":"J. ACM"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1137\/0614001","article-title":"Improved error bounds for underdetermined system solvers","volume":"14","author":"Demmel","year":"1993","journal-title":"SIAM J. Matrix Anal. Appl."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"1081","DOI":"10.1007\/s11517-012-0950-4","article-title":"Adapting source grid parameters to improve the condition of the magnetostatic linear inverse problem of estimating nanoparticle distributions","volume":"50","author":"Eichardt","year":"2012","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_58","unstructured":"Engelbrecht, A.P. (2005). Fundamentals of Swarm Intelligence, Wiley."},{"key":"ref_59","unstructured":"SimBio: A generic environment for bio-numerical simulations. Available online: https:\/\/www.mrt.uni-jena.de\/simbio."},{"key":"ref_60","unstructured":"Dodge, Y. (1987). Statistical Data Analysis Based on the L1 Norm and Related Methods, North Holland\/Elsevier."},{"key":"ref_61","doi-asserted-by":"crossref","unstructured":"Fisher, N.I., Lewis, T., and Embleton, B.J.J. (1987). Statistical Analysis of Spherical Data, Cambridge University Press.","DOI":"10.1017\/CBO9780511623059"},{"key":"ref_62","unstructured":"Tilg, B., Wach, P., Lafer, G., Nenonen, J., and Katila, T. (November, January 31). Simultaneous use of multiple MCG sensor arrays\u2014A study on the localization accuracy. Proceedings of the 18th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1996, Amsterdam, The Netherlands. Bridging Disciplines for Biomedicine."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"305","DOI":"10.1023\/A:1015597910933","article-title":"Visualization of atrial excitation by magnetocardiogram","volume":"28","author":"Sato","year":"2002","journal-title":"Int. J. Cardiovasc. Imaging"},{"key":"ref_64","first-page":"698","article-title":"Filtering characteristics of the human body and reconstruction limits in the inverse problem of electrocardiography","volume":"25","author":"Schneider","year":"1998","journal-title":"Comput. Cardiol."},{"key":"ref_65","unstructured":"Kim, K., Lee, Y.H., Kwon, H., Kim, J.M., Kim, I.S., and Park, Y.K. (2004). Optimal sensor distribution for measuring the tangential field components in MCG. Neurol. Clin. Neurophys., 1, PMID 16012625."},{"key":"ref_66","unstructured":"Jazbin\u0161ek, V., Kosch, O., Meindl, P., Steinhoff, U., Trontelj, Z., and Trahms, L. (2000, January 13\u201317). Multichannel vector MFM and BSPM of chest and back. Proceedings of the 12th International Conference on Biomagnetism Biomag, Espoo, Finland."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"55","DOI":"10.1088\/0143-0815\/12\/A\/011","article-title":"A comparison of normal and tangential magnetic field component measurements in biomagnetic investigations","volume":"12","author":"Diekmann","year":"1991","journal-title":"Clin. Phys. Physiol. Meas."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"1705","DOI":"10.1088\/0031-9155\/41\/9\/010","article-title":"Reconstruction of two-dimensional current distribution from tangential MCG measurement","volume":"41","author":"Kandori","year":"1996","journal-title":"Phys. Med. Biol."},{"key":"ref_69","first-page":"56","article-title":"Design of a SQUID sensor array measuring the tangential field components in magnetocardiogram","volume":"45","author":"Kim","year":"2004","journal-title":"Prog. Supercond."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"648","DOI":"10.1109\/TASC.2005.849983","article-title":"Tangential cardiomagnetic field measurement system based on double relaxation oscillation SQUID planar gradiometers","volume":"15","author":"Lee","year":"2005","journal-title":"IEEE Trans. Appl. Supercond."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"40","DOI":"10.1109\/10.553711","article-title":"Magnetoencephalography with diversely oriented and multicomponent sensors","volume":"44","author":"Hochwald","year":"1997","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"285","DOI":"10.1016\/0033-0620(78)90015-4","article-title":"The pre-excitation syndromes","volume":"20","author":"Gallagher","year":"1978","journal-title":"Prog. Cardiovasc. Dis."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1109\/10.7268","article-title":"Effect of torso boundaries on electric potential and magnetic field of a dipole","volume":"35","author":"Purcell","year":"1988","journal-title":"IEEE Trans. Biomed. Eng."},{"key":"ref_74","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1007\/BF02520014","article-title":"Comparison between electrocardiographic and magnetocardiographic inverse solutions using the boundary element method","volume":"34","author":"Hren","year":"1996","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_75","unstructured":"Mulyadi, I.H., Fiedler, P., Eichardt, R., Zelle, D., Haueisen, J., and Supriyanto, E. (2016). Optimal electrode placement for smart clothing: Compromises between electrophysiological and practical aspects. IEEE J. Biomed. Health Inform., in press."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"237","DOI":"10.1016\/S0167-5273(01)00440-5","article-title":"Reproducibility of HTS-SQUID magnetocardiography in an unshielded clinical environment","volume":"79","author":"Leder","year":"2001","journal-title":"Int. J. Cardiol."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"704","DOI":"10.1002\/pd.1205","article-title":"Prenatal diagnosis of a long QT syndrome by fetal magnetocardiography in an unshielded bedside environment","volume":"25","author":"Schneider","year":"2005","journal-title":"Prenat. Diagn."},{"key":"ref_78","doi-asserted-by":"crossref","unstructured":"Zhang, S.L., Zhang, G.F., Wang, Y.L., Liu, M., Li, H., Qiu, Y., Zeng, J., Kong, X.Y., and Xie, X.M. (2013). Multichannel fetal magnetocardiography using SQUID bootstrap circuit. Chin. Phys. B, 22.","DOI":"10.1088\/1674-1056\/22\/12\/128501"},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"5509","DOI":"10.1088\/0031-9155\/50\/23\/006","article-title":"Optimal filter design for shielded and unshielded ambient noise reduction in fetal magnetocardiography","volume":"50","author":"Comani","year":"2005","journal-title":"Phys. Med. Biol."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"105","DOI":"10.1111\/anec.12140","article-title":"Noninvasive imaging of cardiac excitation: Current status and future perspective","volume":"19","author":"Bhagirath","year":"2014","journal-title":"Ann. Noninvasive Electrocardiol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/754\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:24:25Z","timestamp":1760210665000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/6\/754"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,5,24]]},"references-count":80,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2016,6]]}},"alternative-id":["s16060754"],"URL":"https:\/\/doi.org\/10.3390\/s16060754","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,5,24]]}}}