DeepBrain: A novel human brain interface that non-invasively writes using focused ultrasound

我们如何与人类大脑建立直接的接口？目前的方法是研究植入式电极。然而，由于手术的风险，虽然植入物对患者来说是好的，但它们对一般人群没有吸引力。即使是患者也常常不情愿：尽管人工耳蜗手术越来越多，但成年患者的吸收率仅为5.6%。这项提议旨在测试一种新的非侵入性神经接口，该接口使用超声波直接刺激（写在）人脑上。超声具有高空间分辨率，可到达深部脑结构，可用于引发神经活动（聚焦超声神经调节）和读取神经活动（功能性超声成像）。不幸的是，实现这项技术潜力的障碍是头骨阻碍了声音的传播，吸收了大部分的声能。这使得较低波长的高频超声和较小的刺激焦点不可行。因此，当前的脑深部病灶大于10mm，阻碍了对一个区域内目标的精确刺激。为了实现高分辨率的刺激，我们将避免声音通过头骨传播，并测试一种潜在的替代途径。与目前使用的0.5 MHz经颅刺激频率相比，这种方法将允许使用更高的频率（bbb1mhz）进行“写入”。由于频率更高，因此我们可以在更高的空间分辨率下书写。

How can we build direct interfaces with the human brain? Current approaches are looking at implantable electrodes. However, due to the risks of surgery, while implants are fine for patients, they are not appealing to the general population. Even patients are often reluctant: despite increasing numbers of cochlear implant surgeries, uptake in the adult patient population is only 5.6%. This proposal aims to test a novel non-invasive neural interface that uses ultrasound to directly stimulate (write onto) the human brain. Ultrasound can have a high spatial resolution, reach deep-brain structures, and can be used to both elicit neural activity (focused ultrasound neuromodulation) and to read neural activity (functional ultrasound imaging). Unfortunately, the barrier to realising the potential of this technology is that the skull is in the way of sound propagation, absorbing most of the acoustic energy. This makes higher frequency ultrasound with lower wavelengths and thus a smaller focus of stimulation unfeasible. As a result, current deep-brain foci are more than 10mm large preventing the precise stimulation of targets within a region. To realize high-resolution stimulation, we will avoid sound propagation through the skull and test a potential alternative route. This approach will allow 'writing' using higher frequencies (>1 MHz) compared to the currently used frequencies of 0.5 MHz for transcranial stimulation. Due to the higher frequency, we can therefore write at higher spatial resolutions.