Research press release


Scientific Reports

Neuroscience: A brain-powered wheelchair



今回、Miguel Nicolelisたちは、2匹のアカゲザルに多電極アレイを移植し、これによって無線で脳内の前運動皮質ニューロンと感覚運動皮質ニューロンの活動記録を得られるようにした。次に、この2匹のアカゲザルをそれぞれの車椅子ロボットに座らせて、一定の空間内を移動させ、その間、アカゲザルに車椅子の動きを受動的に観察させ、BMIデコーダーの訓練を行った。これが完了すると、アカゲザルがワイヤレスBMIシステムを使って車椅子で移動できるようにして、3つの出発点のいずれか1つから食物の報酬(ブドウ)の置かれた目標地点まで移動させてみた。その結果、このBMIがサルの脳活動を車椅子の方向性のある動きに変換して、この課題を完了できることが分かった。また、Nicolelisたちは、サルが車椅子を操縦する能力が時間の経過とともに向上したことも明らかにしたが、訓練を受けたサルの脳構造が変化したことが関係している可能性もある。

A wireless brain-machine-interface (BMI) which allows a monkey to control the movements of a robotic wheelchair is described in Scientific Reports this week. The results suggest that BMIs similar to this one may be able to help restore mobility to severely paralysed patients in the future.

BMIs have previously been developed which allow primates to use cortical activity to control artificial limbs. However, it is unknown if recordings from cortical implants in the brain could be translated into whole-body movements.

Miguel Nicolelis and colleagues implanted two rhesus monkeys with multi-electrode arrays that allowed wireless recordings to be made of premotor and sensorimotor cortical neurons in the brain. The monkeys were then seated in a robotic wheelchair and passively observed the movements of the chair as it navigated around a space, in order to train a BMI decoder. Once this had been completed, the monkeys attempted to navigate in the wheelchair, using the wireless BMI system, from one of three starting positions to a target location, where a food reward (grape) had been placed. The authors found that the BMI was capable of translating the monkeys’ brain activity into directional movements in the wheelchair in order to complete the task. They also found that over time the monkeys improved their ability to navigate in the wheelchair, which may have been mediated by changes in their brain structure in response to training.

doi: 10.1038/srep22170


メールマガジンリストの「Nature 関連誌今週のハイライト」にチェックをいれていただきますと、毎週各ジャーナルからの最新の「注目のハイライト」をまとめて皆様にお届けいたします。