Quantum diamond magnetometry for magnetocardiography

钻石是最有名的珠宝，但通过添加称为氮空位中心（NVCs）的特殊杂质，它们变得粉红色而不是无色。每个NVC的行为就像一个原子，具有有用的量子行为，包括它们对磁场敏感的事实。我们已经使用了一个钻石与许多NVCs建立一个非常敏感的磁力计。它不需要冷却或加热，这使得它更适合于包括我们正在关注的医疗应用在内的应用。在这个项目中，我们的目标是提高灵敏度，足以看到我们心跳产生的微小磁场。这就是所谓的心磁图（MCG）。心跳产生的磁场比地球磁场弱一百万倍。在这个项目中，我们将使我们的金刚石磁力计的灵敏度提高10倍，但是我们仍然需要使它的灵敏度再次提高至少10倍才能在医学上有用。我们将结合联合收割机量子和经典工程来实现这一点。检测MCG应该有助于我们（在这个为期6个月的项目的时间表后的进一步工作中）预测心源性猝死（SCD），这是所有心脏病死亡的一半原因。当心脏的电功能发生故障并且不受调节的传导模式占主导地位时，就会发生SCD。这可能导致心脏无法输出血液，并迅速导致危及生命的情况。已知MCG在医学上是有用的，但迄今为止还没有成功地商业化，因为它需要昂贵的磁力计，磁力计必须被低温冷却。MCG的一个优点是它是完全非侵入性的，因为它只涉及检测我们心脏自然发出的磁场。

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.