Medicine · In service today
Biomagnetic sensing
SQUIDs read the magnetic field of brain activity through the skull.
The record behind biomagnetic sensing
Superconducting magnetometers for brain investigations · PMCSuperconductors in biomagnetic sensing
The magnetic field produced by activity in the brain is a minute fraction of the earth’s own, and measuring it through the skull was impossible until superconducting quantum interference devices existed. A SQUID is a superconducting loop interrupted by Josephson junctions, and its output swings through a full cycle for one quantum of magnetic flux threading the loop. Its sensitivity therefore comes from a physical constant rather than from an amplifier. Nothing built on conventional electronics has caught up.
What is stopping biomagnetic sensing
Everything around the sensor. A magnetically shielded room and a helium dewar held over a patient’s head are the cost, not the SQUID, and that is what has kept the technique inside research hospitals. The competition is not a better superconductor: it is a class of room-temperature optical magnetometer that needs no cryogen at all.
What a better material would change for biomagnetic sensing
A sensor that reached this noise floor at liquid-nitrogen temperature would take the dewar, and most of the cost, out of the room. That is a materials problem rather than an electronics one: the families that reach the temperature are also noisier, and closing that gap is what would put a scanner in a clinic instead of a research hospital.
Conductors used in biomagnetic sensing
Near biomagnetic sensing, in medicine
SuperMatics is a platform infrastructure company for superconducting devices: software that finds the material and the process, lab work that makes and measures it, and pilot manufacturing with industrial partners.If you are working on something in this field and a material is what stands in the way, tell us about it.