Cajigas Iahn, Davis Kevin C, Meschede-Krasa Benyamin, Prins Noeline W, Gallo Sebastian, Naeem Jasim Ahmad, Palermo Anne, Wilson Audrey, Guerra Santiago, Parks Brandon A, Zimmerman Lauren, Gant Katie, Levi Allan D, Dietrich W Dalton, Fisher Letitia, Vanni Steven, Tauber John Michael, Garwood Indie C, Abel John H, Brown Emery N, Ivan Michael E, Prasad Abhishek, Jagid Jonathan
Department of Neurological Surgery, University of Miami, Miami, FL 33136, USA.
Department of Biomedical Engineering, University of Miami, Miami, FL 33146, USA.
Brain Commun. 2021 Oct 21;3(4):fcab248. doi: 10.1093/braincomms/fcab248. eCollection 2021.
Loss of hand function after cervical spinal cord injury severely impairs functional independence. We describe a method for restoring volitional control of hand grasp in one 21-year-old male subject with complete cervical quadriplegia (C5 American Spinal Injury Association Impairment Scale A) using a portable fully implanted brain-computer interface within the home environment. The brain-computer interface consists of subdural surface electrodes placed over the dominant-hand motor cortex and connects to a transmitter implanted subcutaneously below the clavicle, which allows continuous reading of the electrocorticographic activity. Movement-intent was used to trigger functional electrical stimulation of the dominant hand during an initial 29-weeks laboratory study and subsequently via a mechanical hand orthosis during in-home use. Movement-intent information could be decoded consistently throughout the 29-weeks in-laboratory study with a mean accuracy of 89.0% (range 78-93.3%). Improvements were observed in both the speed and accuracy of various upper extremity tasks, including lifting small objects and transferring objects to specific targets. At-home decoding accuracy during open-loop trials reached an accuracy of 91.3% (range 80-98.95%) and an accuracy of 88.3% (range 77.6-95.5%) during closed-loop trials. Importantly, the temporal stability of both the functional outcomes and decoder metrics were not explored in this study. A fully implanted brain-computer interface can be safely used to reliably decode movement-intent from motor cortex, allowing for accurate volitional control of hand grasp.
颈脊髓损伤后手功能丧失严重损害功能独立性。我们描述了一种方法，在家庭环境中，使用便携式完全植入式脑机接口，为一名21岁的完全性颈髓损伤男性患者（美国脊髓损伤协会损伤分级C5，A级）恢复手部抓握的自主控制。该脑机接口由置于优势手运动皮层上方的硬膜下表面电极组成，并连接至植入锁骨下方皮下的发射器，从而能够持续读取皮层电图活动。在最初为期29周的实验室研究中，利用运动意图触发优势手的功能性电刺激，随后在家庭使用期间通过机械手部矫形器进行触发。在整个29周的实验室研究中，运动意图信息能够持续被解码，平均准确率为89.0%（范围78 - 93.3%）。在各种上肢任务的速度和准确性方面均有改善，包括拿起小物体以及将物体转移至特定目标。开环试验期间的家庭解码准确率达到91.3%（范围80 - 98.95%），闭环试验期间的准确率为88.3%（范围77.6 - 95.5%）。重要的是，本研究未探讨功能结果和解码器指标的时间稳定性。完全植入式脑机接口可安全用于可靠地从运动皮层解码运动意图，从而实现对手部抓握的精确自主控制。
