Realising the potential of magnetoencephalography (MEG) using Optically Pumped Magnetometers (OPMs)

在英国，大约有60万人患有癫痫；超过22万人正在接受精神分裂症的治疗；70万人患有自闭症谱系障碍(ASD)，每90秒就有一人因头部受伤而入院。对于这些人中的许多人来说，常规的脑部扫描(例如核磁共振)的价值将是有限的。例如，在癫痫儿童中，MRI通常无法发现异常，而当发现异常时，往往无法确定该异常是否会导致癫痫发作。在创伤性脑损伤(TBI)中，大多数损伤(~70%)被归类为“轻度”(mTBI-更常被称为脑震荡)。其中，大约30%的人会出现衰弱的症状，但结构成像没有显示异常。同样，在精神分裂症和自闭症患者中，个体不太可能在常规成像中显示异常。这些例子(以及许多其他例子)突显了开发新的成像形式的迫切需要，这种成像形式可以为一系列神经和精神疾病提供客观的诊断、预后和治疗计划。脑磁图(MEG)是一种测量大脑功能(即我们的脑细胞做什么)的成像技术。使用放置在头部附近的传感器，脑磁图测量了当我们执行心理任务时流经神经元集合的小电流。它可以跟踪健康的大脑活动，以及这种活动在疾病中是如何分解的。它已被证明具有癫痫的能力，它可以以95%的准确率对脑震荡患者进行分类。它还可以看到精神分裂症和自闭症患者的大脑活动有何不同。然而，它也有缺点：在传统扫描仪中，传感技术笨重、复杂、极其昂贵；患者不得不长时间保持不动；它不能适应不同头部大小的人，难以在儿童身上使用。即使在成年人中，敏感度(大脑接收信号的能力)和空间分辨率(我们能准确定位大脑的特定区域)都是有限的。我们设计了一种新型的脑磁图扫描仪，使用的传感器又小又轻(就像乐高积木一样)。传感器可以安装在轻便的头盔中(类似于自行车头盔)。由于传感器与头部一起移动，即使患者四处移动，也可以生成良好的扫描结果。头盔可以有不同的尺寸，所以我们可以改装扫描仪来扫描任何年龄的人。这种“可穿戴”系统还能以更高的空间分辨率和灵敏度测量大脑活动。它的购买价格要便宜得多，而且更容易维护。这种被称为OPM-MEG扫描仪的设备是非常新的。我们已经用一个拥有192个传感器的原型证明了它的能力，但这还不足以提供OPM-MEG所允许的高灵敏度和精确度。此外，目前的版本有笨重的电子设备，使得它很难使用。在这里，我们寻求购买设备，以便建造一个大大增强的系统，可以用于尖端医学研究。该系统将拥有384个传感器；它将比世界上任何其他脑磁图扫描仪都更灵敏，空间分辨率更高。它将拥有紧凑的电子设备，放在受试者佩戴的小背包中。这将使我们能够在人们行走时扫描他们。该扫描仪将作为国家设施运行，这意味着来自英国各地的研究人员将使用它进行许多不同的研究项目。一些例子项目包括扫描患有癫痫的婴儿，了解脑震荡，测量精神分裂症的大脑活动，扫描走路时容易摔倒的老年人，同时扫描母亲和婴儿，以了解婴儿是如何从父母那里学习的，以及在自闭症等疾病中这种学习是如何出错的。这些只是我们将支持的几个项目的例子。由于OPM-MEG简单、实用、成本较低，因此非常适合临床应用。这种设备是在医院使用这项新技术的第一步。

In the UK around 600,000 people are living with epilepsy; over 220,000 people are being treated for schizophrenia; 700,000 people have autistic spectrum disorder (ASD), and every 90 seconds one person is admitted to hospital with a head injury. For many of these individuals, conventional brain scanning (e.g. MRI) will be of limited value. For example, in children with epilepsy, MRI often fails to spot an abnormality, and when it does it is frequently unclear whether that abnormality is driving seizures. In traumatic brain injury (TBI), most injuries (~70%) are classified as "mild" (mTBI - more often called concussion). Of these, around 30% go on to produce debilitating symptoms, yet structural imaging shows no abnormality. Likewise in schizophrenia and ASD, individuals are unlikely to show anomalies in conventional imaging. These examples (and many others) highlight the critical need to develop new forms of imaging which can provide objective diagnosis, prognosis, and treatment planning for a range of neurological and psychiatric disorders.Magnetoencephalography (MEG) is an imaging technology which measures brain function (i.e. what our brain cells do). Using sensors placed close to the head, MEG measures the small currents that flow through assemblies of neurons as we carry out mental tasks. It can track healthy brain activity, and how such activity breaks down in disease. It has proven capability in epilepsy, and it can classify patients with concussion with >95% accuracy. It can also see how brain activity differs in people with schizophrenia, and autism. However, it has drawbacks: In conventional scanners, the sensing technology is bulky, complicated and extremely expensive; patients have to stay still for long periods; it cannot adapt to people with different head size and is difficult to use in children. Even in adults, both sensitivity (how well it picks up signals from the brain) and spatial resolution (how well we can pinpoint a specific area of the brain) is limited. We have designed a new type of MEG scanner using sensors that are small and lightweight (like Lego bricks). The sensors can be mounted into lightweight helmets (similar to bike helmets). Because the sensors move with the head, good scans can be generated even if patients move around. Helmets can come in different sizes, so we can adapt the scanner to scan people of any age. This "wearable" system can also measure brain activity with greater spatial resolution and sensitivity. It is much cheaper to buy, and easier to maintain. This device - called an OPM-MEG scanner - is very new. We have proven its capability with a prototype which has 192 sensors, but this isn't enough to offer the high sensitivity and precision that OPM-MEG allows. Also, the current version has cumbersome electronics which make it hard to use. Here, we seek to buy the equipment to allow construction of a greatly enhanced system, which can be used for cutting-edge medical researchThe system will have 384 sensors; it will be more sensitive and have higher spatial resolution than any other MEG scanner in the world. It will have compact electronics which will sit in a small backpack worn by the subject. This will allow us to scan people as they walk. The scanner will be operated as a national facility meaning researchers from across the UK will use it for lots of different research projects. Some example projects include scanning infants with epilepsy, understanding concussion, measuring brain activity in schizophrenia, scanning elderly people who are prone to falling as they walk, and scanning a mother and baby at the same time to understand how infants learn from their parents, and how that goes wrong in disorders like autism. These are just a few examples of projects we will support. Because OPM-MEG is simple, practical, and lower cost, it is highly suited to clinical practice. This equipment is the first step along a path to using this new technology in hospitals.