Mainz, Stuttgart, Freiburg and Q.ANT Recorded a Human Magnetocardiogram With Room-Temperature Diamond Sensors: What the 16 September 2026 Science Advances Paper Shows
Quentir Medicine Monitor
Evidence-based insights for quantum medicine.
Three research groups in Germany have measured the magnetic field of a beating human heart with diamond sensing crystals smaller than half a cubic millimeter, at room temperature and without touching the skin. The paper appeared in Science Advances on 16 September 2026 under the coordination of Muhib Omar and Arne Wickenbrock of Johannes Gutenberg University Mainz, with Dmitry Budker and Jörg Wrachtrup among its 30 authors.
The instruments are diamond nitrogen-vacancy magnetometers: a nitrogen atom sitting beside a missing carbon atom in the diamond lattice, whose electron spin shifts its energy in proportion to the surrounding magnetic field. The three systems, built independently at Mainz, at the University of Stuttgart and by the Stuttgart startup Q.ANT GmbH, each produced a human magnetocardiogram in proof-of-concept self-experiments on members of the research groups, with sensitivities between 6 and 26 picotesla per square-root hertz. The result is a laboratory measurement on a handful of volunteers from the teams themselves, with no patient involved. It establishes that room-temperature diamond sensors can read the heart's field at all, after averaging, which is the step a cryogenic SQUID cleared decades ago and an optically pumped magnetometer clears with a heated vapor cell. The half-cubic-millimeter figure describes the sensing crystal, not the complete instrument with its fiber, optics and electronics, and the diamond heads recorded without touching the skin while a conventional electrocardiogram supplied the timing reference for the averaging, so the experiments did not show an electrode-free workflow.
The heart's magnetic signal is faint. The paper puts the average R-peak, the sharpest feature of each beat, at about 25 picotesla, roughly two million times weaker than the field of the Earth. That is why magnetocardiography has stayed inside hospitals that could afford superconducting detectors and the shielding around them, and why a SQUID magnetocardiograph still counts as deployable news when a Chinese manufacturer places one. The Mainz group's own line of work reached a related milestone on 6 August 2026 with a levitated-magnet sensor at 32 femtotesla per square-root hertz, a sensitivity reached only in a narrow resonance near 305 hertz, on a benchtop device that is far less suited than a diamond to sitting near a chest.