{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,16]],"date-time":"2026-06-16T14:51:36Z","timestamp":1781621496345,"version":"3.54.5"},"reference-count":39,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,21]],"date-time":"2024-08-21T00:00:00Z","timestamp":1724198400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"SandboxAQ"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Decades of research have shown that magnetocardiography (MCG) has the potential to improve cardiac care decisions. However, sensor and system limitations have prevented its widespread adoption in clinical practice. We report an MCG system built around an array of scalar, optically pumped magnetometers (OPMs) that effectively rejects ambient magnetic interference without magnetic shielding. We successfully used this system, in conjunction with custom hardware and noise rejection algorithms, to record magneto-cardiograms and functional magnetic field maps from 30 volunteers in a regular downtown office environment. This demonstrates the technical feasibility of deploying our device architecture at the point-of-care, a key step in making MCG usable in real-world settings.<\/jats:p>","DOI":"10.3390\/s24165402","type":"journal-article","created":{"date-parts":[[2024,8,23]],"date-time":"2024-08-23T12:58:07Z","timestamp":1724417887000},"page":"5402","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Bedside Magnetocardiography with a Scalar Sensor Array"],"prefix":"10.3390","volume":"24","author":[{"given":"Geoffrey Z.","family":"Iwata","sequence":"first","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0259-6309","authenticated-orcid":false,"given":"Christian T.","family":"Nguyen","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kevin","family":"Tharratt","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9116-6214","authenticated-orcid":false,"given":"Maximilian","family":"Ruf","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tucker","family":"Reinhardt","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jordan","family":"Crivelli-Decker","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Madelaine S. Z.","family":"Liddy","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alison E.","family":"Rugar","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Frances","family":"Lu","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kirstin","family":"Aschbacher","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ethan J.","family":"Pratt","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kit Yee","family":"Au-Yeung","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-2999-457X","authenticated-orcid":false,"given":"Stefan","family":"Bogdanovic","sequence":"additional","affiliation":[{"name":"SandboxAQ, Palo Alto, CA 94301, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,21]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Murzin, D., Mapps, D.J., Levada, K., Belyaev, V., Omelyanchik, A., Panina, L., and Rodionova, V. (2020). Ultrasensitive Magnetic Field Sensors for Biomedical Applications. Sensors, 20.","DOI":"10.3390\/s20061569"},{"key":"ref_2","first-page":"2441","article-title":"Diagnostic outcomes of magnetocardiography in patients with coronary artery disease","volume":"8","author":"Li","year":"2015","journal-title":"Int. J. Clin. Exp. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"022005","DOI":"10.1088\/2631-8695\/ac0838","article-title":"Magnetic sensors-A review and recent technologies","volume":"3","author":"Khan","year":"2021","journal-title":"Eng. Res. Express"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"291","DOI":"10.1111\/j.1542-474X.2012.00538.x","article-title":"Magnetocardiography for the diagnosis of coronary artery disease: A systematic review and meta-analysis","volume":"17","author":"Agarwal","year":"2012","journal-title":"Ann Noninvasive Electrocardiol."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1424","DOI":"10.1253\/circj.CJ-09-0975","article-title":"Non-Invasive Magnetocardiography for the Early Diagnosis of Coronary Artery Disease in Patients Presenting with Acute Chest Pain","volume":"74","author":"Kwon","year":"2010","journal-title":"Circ. J."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Bhat, V.R., Pal, B., Anitha, H., and Thalengala, A. (2022). Localization of magnetocardiographic sources for myocardial infarction cases using deterministic and Bayesian approaches. Sci. Rep., 12.","DOI":"10.1038\/s41598-022-25919-3"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1016\/j.jelectrocard.2019.07.009","article-title":"Clinical utility of magnetocardiography in cardiology for the detection of myocardial ischemia","volume":"57","author":"Camm","year":"2019","journal-title":"J. Electrocardiol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"M\u00e4ntynen, V., Konttila, T., and Stenroos, M. (2014). Investigations of sensitivity and resolution of ECG and MCG in a realistically shaped thorax model. Phys. Med. Biol., 59.","DOI":"10.1088\/0031-9155\/59\/23\/7141"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Alday, E.A.P., Ni, H., Zhang, C., Colman, M.A., Gan, Z., and Zhang, H. (2016). Comparison of Electric- and Magnetic-Cardiograms Produced by Myocardial Ischemia in Models of the Human Ventricle and Torso. PLoS ONE, 11.","DOI":"10.1371\/journal.pone.0160999"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"ehab724.1171","DOI":"10.1093\/eurheartj\/ehab724.1171","article-title":"Value of magnetocardiography in chronic coronary disease detection: Results of multicenter trial","volume":"42","author":"Chaikovsky","year":"2021","journal-title":"Eur. Heart J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e038804","DOI":"10.1136\/bmjopen-2020-038804","article-title":"MAGNETO cardiography parameters to predict future Sudden Cardiac Death (MAGNETO-SCD) or ventricular events from implantable cardioverter defibrillators: Study protocol, design and rationale","volume":"10","author":"Lachlan","year":"2020","journal-title":"BMJ Open"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1111\/j.1542-474X.2008.00217.x","article-title":"Resting Magnetocardiography Predicts 3-Year Mortality in Patients Presenting with Acute Chest Pain without ST Segment Elevation","volume":"13","author":"Park","year":"2008","journal-title":"Ann. Noninvasive Electrocardiol."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"152","DOI":"10.1111\/j.1542-474X.2005.05611.x","article-title":"Magnetocardiogram Recordings in a Nonshielded Environment-Reproducibility and Ischemia Detection","volume":"10","author":"Steinberg","year":"2005","journal-title":"Ann. Noninvasive Electrocardiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"100466","DOI":"10.1016\/j.ijcha.2019.100466","article-title":"A 90-second magnetocardiogram using a novel analysis system to assess for coronary artery stenosis in Emergency department observation unit chest pain patients","volume":"26","author":"Pena","year":"2020","journal-title":"IJC Heart Vasc."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"107","DOI":"10.1007\/s10439-008-9598-5","article-title":"Magnetocardiography based spatiotemporal correlation analysis is superior to conventional ECG analysis for identifying myocardial injury","volume":"37","author":"Goernig","year":"2009","journal-title":"Ann. Biomed. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"116","DOI":"10.2152\/jmi.54.116","article-title":"Visualization of cardiac dipole using a current density map: Detection of cardiac current undetectable by electrocardiography using magnetocardiography","volume":"54","author":"Ikefuji","year":"2007","journal-title":"J. Med. Investig."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"533","DOI":"10.1080\/07853890903107883","article-title":"Detection of non-ST-elevation myocardial infarction using magnetocardiogram: New information from spatiotemporal electrical activation map","volume":"41","author":"Kim","year":"2009","journal-title":"Ann. Med."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Chang, Y.C., Wu, C.C., Lin, C.H., Wu, Y.W., Yang, Y.C., Chang, T.J., Jiang, Y.D., and Chuang, L.M. (2015). Early Myocardial Repolarization Heterogeneity Is Detected by Magnetocardiography in Diabetic Patients with Cardiovascular Risk Factors. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0133192"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Fokoua-Maxime, C.D., Lontchi-Yimagou, E., Cheuffa-Karel, T.E., Tchato-Yann, T.L., and Pierre-Choukem, S. (2021). Prevalence of asymptomatic or \u201csilent\u201d myocardial ischemia in diabetic patients: Protocol for a systematic review and meta-analysis. PLoS ONE, 16.","DOI":"10.1371\/journal.pone.0252511"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1016\/j.hrthm.2008.02.035","article-title":"Magnetocardiography for fetal arrhythmias","volume":"5","author":"Strasburger","year":"2008","journal-title":"Heart Rhythm."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.jacep.2017.08.009","article-title":"Detection of Fetal Arrhythmia by Using Optically Pumped Magnetometers","volume":"4","author":"Batie","year":"2018","journal-title":"JACC Clin. Electrophysiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"S2","DOI":"10.1016\/j.annemergmed.2018.08.008","article-title":"Magnetocardiography Using a Novel Analysis System (Cardioflux) in the Evaluation of Emergency Department Observation Unit Chest Pain Patients","volume":"72","author":"Pena","year":"2018","journal-title":"Ann. Emerg. Med."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Mooney, J.W., Ghasemi-Roudsari, S., Banham, E.R., Symonds, C., Pawlowski, N., and Varcoe, B.T.H. (2017). A portable diagnostic device for cardiac magnetic field mapping. Biomed. Phys. Eng. Express, 3.","DOI":"10.1088\/2057-1976\/3\/1\/015008"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Yang, Y., Xu, M., Liang, A., Yin, Y., Ma, X., Gao, Y., and Ning, X. (2021). A new wearable multichannel magnetocardiogram system with a SERF atomic magnetometer array. Sci. Rep., 11.","DOI":"10.1038\/s41598-021-84971-7"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Zhai, Y., Yue, Z., Li, L., and Liu, Y. (2022). Progress and applications of quantum precision measurement based on SERF effect. Front. Phys., 10.","DOI":"10.3389\/fphy.2022.969129"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"598","DOI":"10.1016\/j.neuroimage.2019.05.063","article-title":"Optically pumped magnetometers: From quantum origins to multi-channel magnetoencephalography","volume":"199","author":"Tierney","year":"2019","journal-title":"NeuroImage"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2552","DOI":"10.1109\/TIM.2019.2949205","article-title":"1-pT Noise Fluxgate Magnetometer for Geomagnetic Measurements and Unshielded Magnetocardiography","volume":"69","author":"Janosek","year":"2020","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"060018","DOI":"10.1063\/1.5028788","article-title":"Feasibility study on measurement of magnetocardiography (MCG) using fluxgate magnetometer","volume":"1942","author":"Sengottuvel","year":"2018","journal-title":"AIP Conf. Proc."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Kurashima, K., Kataoka, M., Nakano, T., Fujiwara, K., Kato, S., Nakamura, T., Yuzawa, M., Masuda, M., Ichimura, K., and Okatake, S. (2023). Development of Magnetocardiograph without Magnetically Shielded Room Using High-Detectivity TMR Sensors. Sensors, 23.","DOI":"10.3390\/s23020646"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Clancy, R.J., Gerginov, V., Alem, O., Becker, S., and Knappe, S. (2021). A study of scalar optically-pumped magnetometers for use in magnetoencephalography without shielding. Phys. Med. Biol., 66.","DOI":"10.1088\/1361-6560\/ac18fb"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"ehaa946.0386","DOI":"10.1093\/ehjci\/ehaa946.0386","article-title":"Performance of miniature scalar atomic magnetometers for magnetocardiography in an unshielded hospital laboratory for clinical electrophysiology","volume":"41","author":"Fenici","year":"2020","journal-title":"Eur. Heart J."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"025001","DOI":"10.1088\/1367-2630\/acb840","article-title":"How to build a magnetometer with thermal atomic vapor: A tutorial","volume":"25","author":"Fabricant","year":"2023","journal-title":"New J. Phys."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"eadg1746","DOI":"10.1126\/sciadv.adg1746","article-title":"A movable unshielded magnetocardiography system","volume":"9","author":"Xiao","year":"2023","journal-title":"Sci. Adv."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.sna.2005.09.036","article-title":"Laser-pumped cesium magnetometers for high-resolution medical and fundamental research","volume":"129","author":"Groeger","year":"2006","journal-title":"Sens. Actuators Phys."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"A15392","DOI":"10.1161\/circ.148.suppl_1.15392","article-title":"Abstract 15392: Performance of a Novel Unshielded Magnetocardiography Device in a First-in-Human Study","volume":"148","author":"Lu","year":"2023","journal-title":"Circulation"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Zhang, R., Smith, K., and Mhaskar, R. (November, January 30). Highly sensitive miniature scalar optical gradiometer. Proceedings of the 2016 IEEE SENSORS, Orlando, FL, USA. Available online: https:\/\/ieeexplore.ieee.org\/document\/7808768.","DOI":"10.1109\/ICSENS.2016.7808768"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"135","DOI":"10.1007\/BF02534144","article-title":"Signal-space projection method for separating MEG or EEG into components","volume":"35","author":"Uusitalo","year":"1997","journal-title":"Med. Biol. Eng. Comput."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1016\/j.jelectrocard.2007.03.013","article-title":"Detection of patients with coronary artery disease using cardiac magnetic field mapping at rest","volume":"40","author":"Gapelyuk","year":"2007","journal-title":"J. Electrocardiol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"e12715","DOI":"10.1111\/anec.12715","article-title":"Magnetocardiography for identification of coronary ischemia in patients with chest pain and normal resting 12-lead electrocardiogram","volume":"25","author":"Ramesh","year":"2020","journal-title":"Ann. Noninvasive Electrocardiol."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5402\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:40:29Z","timestamp":1760110829000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5402"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,21]]},"references-count":39,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["s24165402"],"URL":"https:\/\/doi.org\/10.3390\/s24165402","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,21]]}}}