IEEE Trans Biomed Eng. 2021 Jul;68(7):2313-2325. doi: 10.1109/TBME.2021.3069119. Epub 2021 Jun 17.
Individuals with neurological disease or injury such as amyotrophic lateral sclerosis, spinal cord injury or stroke may become tetraplegic, unable to speak or even locked-in. For people with these conditions, current assistive technologies are often ineffective. Brain-computer interfaces are being developed to enhance independence and restore communication in the absence of physical movement. Over the past decade, individuals with tetraplegia have achieved rapid on-screen typing and point-and-click control of tablet apps using intracortical brain-computer interfaces (iBCIs) that decode intended arm and hand movements from neural signals recorded by implanted microelectrode arrays. However, cables used to convey neural signals from the brain tether participants to amplifiers and decoding computers and require expert oversight, severely limiting when and where iBCIs could be available for use. Here, we demonstrate the first human use of a wireless broadband iBCI.
Based on a prototype system previously used in pre-clinical research, we replaced the external cables of a 192-electrode iBCI with wireless transmitters and achieved high-resolution recording and decoding of broadband field potentials and spiking activity from people with paralysis. Two participants in an ongoing pilot clinical trial completed on-screen item selection tasks to assess iBCI-enabled cursor control.
Communication bitrates were equivalent between cabled and wireless configurations. Participants also used the wireless iBCI to control a standard commercial tablet computer to browse the web and use several mobile applications. Within-day comparison of cabled and wireless interfaces evaluated bit error rate, packet loss, and the recovery of spike rates and spike waveforms from the recorded neural signals. In a representative use case, the wireless system recorded intracortical signals from two arrays in one participant continuously through a 24-hour period at home.
Wireless multi-electrode recording of broadband neural signals over extended periods introduces a valuable tool for human neuroscience research and is an important step toward practical deployment of iBCI technology for independent use by individuals with paralysis. On-demand access to high-performance iBCI technology in the home promises to enhance independence and restore communication and mobility for individuals with severe motor impairment.
患有肌萎缩性侧索硬化症、脊髓损伤或中风等神经系统疾病或损伤的个体可能会四肢瘫痪,无法说话甚至无法交流。对于这些情况的患者,目前的辅助技术通常无效。脑机接口正在被开发出来,以增强独立性并在没有身体运动的情况下恢复交流。在过去的十年中,四肢瘫痪的个体使用皮层内脑机接口(iBCI)实现了快速屏幕打字和点击平板电脑应用程序的控制,该接口通过植入微电极阵列记录的神经信号解码意图的手臂和手部运动。然而,用于从大脑传递神经信号的电缆将参与者束缚到放大器和解码计算机上,并需要专家监督,严重限制了 iBCI 何时何地可用于使用。在这里,我们展示了第一个无线宽带 iBCI 的人体使用。
基于之前在临床前研究中使用的原型系统,我们用无线发射器取代了 192 电极 iBCI 的外部电缆,并实现了瘫痪患者宽带场电位和尖峰活动的高分辨率记录和解码。正在进行的试点临床试验中的两名参与者完成了屏幕上的项目选择任务,以评估 iBCI 支持的光标控制。
有线和无线配置之间的通信比特率相等。参与者还使用无线 iBCI 控制标准商业平板电脑浏览网页和使用几个移动应用程序。在有线和无线接口的日内比较中,评估了误码率、数据包丢失以及从记录的神经信号中恢复尖峰率和尖峰波形。在一个代表性的用例中,无线系统连续记录了一名参与者的两个阵列的皮层内信号,持续了 24 小时。
无线宽带神经信号的多电极记录为人类神经科学研究引入了一种有价值的工具,并且是向瘫痪患者独立使用 iBCI 技术的实际部署迈出的重要一步。按需访问家庭中的高性能 iBCI 技术有望增强独立性并恢复严重运动障碍患者的交流和移动能力。