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

我们如何才能与人脑建立直接的接口？目前的方法是寻找可植入的电极。然而，由于手术的风险，虽然植入物对患者来说很好，但对普通民众来说并不吸引人。即使是患者也常常不情愿：尽管人工耳蜗手术的数量不断增加，但成年患者群体的吸入率只有5.6%。这项提议旨在测试一种新型的非侵入性神经接口，它使用超声波直接刺激(写入)人脑。超声波具有很高的空间分辨率，可以到达大脑深层结构，可以用来诱发神经活动(聚焦超声神经调节)和读取神经活动(功能超声成像)。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，吸收了大部分声能。这使得高频超声波的波长更低，因此刺激的焦点更小是不可行的。因此，目前的脑深部病灶超过10毫米，阻碍了对区域内目标的精确刺激。为了实现高分辨率刺激，我们将避免声音通过头骨传播，并测试一条潜在的替代路线。与目前用于经颅刺激的0.5 MHz频率相比，这种方法将允许使用更高的频率(&gt；1 MHz)进行写入。由于频率较高，因此我们可以以较高的空间分辨率进行写入。

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.