Heart disease is the most common cause of death worldwide. When someone complains of chest pains it may be that there is nothing to worry about, but doctors need to check, which can take up to 12 hours. A quicker test would be reassuring for the patient and save NHS resources. In future this may be done by measuring magnetic fields with our diamond sensors: Every time your heart beats, it emits a tiny magnetic field that is a million times weaker than the Earth’s magnetic field.

How can a diamond detect magnetic fields? We have built our sensors around diamonds grown in the UK by Element Six. They are pink because of defects we’ve put in called nitrogen vacancy defects: a nitrogen atom next to a missing carbon atom. We shine in a green laser and detect the pink light the defects give off. The amount of pink light tells us the quantum state of the defects, and this depends on the magnetic field when we shine in microwaves. Our sensors work at room temperature with no need for vacuum, so would be convenient for doctors. We’re working with cardiologists and companies towards bringing our research into hospitals.

Read more:

• MW Dale & GW Morley, Medical applications of diamond magnetometry: commercial viability, arXiv:1705.01994 (2017).
• NQIT Impact Case Study: Diamond Sensors with Bruker

Image: diamond containing nitrogen vacancies fluorescing due to illumination with green light, by Jon Newland