Noninvasive magnetocardiography of a living rat based on a diamond quantum sensor

Diamond-based nitrogen-vacancy (N-V) centers hold the potential to overcome the sensor limitations for magnetocardiography (MCG), but their invasive measurement scheme is incompatible with clinical settings. This study presents a noninvasive diamond MCG system based on N-V center ensembles enhanced by techniques such as magnetic flux concentration, and demonstrates a practical instance of noninvasive MCG measurement on a living animal. These results mark a substantial step toward deploying diamond MCG in biophysical applications, highlighting its future potential in biomagnetic observations.