Quantum diamond magnetometry for magnetocardiography

Diamonds are best known as jewellery but by adding particular impurities called nitrogen vacancy centres (NVCs) they become pink instead of colourless. Each NVC behaves like an atom with useful quantum behaviour including the fact that they are sensitive to magnetic fields. We have used a diamond with many NVCs to build a very sensitive magnetometer. It doesn't require cooling or heating which makes it more suitable for applications including the medical applications we are focusing on.

In this project we aim to improve the sensitivity enough to see the tiny magnetic fields created by our heartbeats. This is called magnetocardiography (MCG). The magnetic field from a heartbeat is one million times weaker than the Earth's magnetic field. We will make our diamond magnetometer up to ten times more sensitive in this project, but then we would still need to make it at least 10 times more sensitive again to be medically useful. We will combine quantum and classical engineering to achieve this.

Detecting MCG should help us (in further work after the timescale of this 6-month project) to predict sudden cardiac death (SCD), which is responsible for half of all heart disease deaths. SCD occurs when the electrical function of the heart malfunctions and unregulated patterns of conduction predominate. This can cause the heart to fail to output blood and rapidly lead to a life threatening situation. MCG is known to be medically useful but has not been successfully commercialised so far because it has required expensive magnetometers that must be cryogenically cooled. An advantage of MCG is that it is completely non-invasive as it simply involves detecting the magnetic fields that are naturally emitted by our hearts.