バイオフィードバックを用いたポリオ経験者の筋神経系制御能力の改善とロボットスーツHALによる麻痔肢動作支援

摘要

Polio survivors with severe limb paralysis cannot move their limbs voluntarily because they have a significantly reduced number of motor neurons due to the poliovirus infection. There is a danger that their ability to control their neuromuscular system, in particular fundamental abilities such as balancing flexors and extensors in the neuromuscular system may decrease dramatically in the long term. If such polio survivors could improve their ability to balance, it would be possible for them to use the "Robot Suit HAL" wearable movement support device. HAL anticipates its wearer's intended movements through the measurement of bioelectrical signals, and generates assistive torques to support their movements. This study proposes a biofeedback training method using visual information, with the objective of restoring motor functions using HAL. A biofeedback system that feeds back bioelectrical signals visually was developed, and tested with a polio survivor. The polio survivor was able to adjust the balance of their muscular control through the proposed training method, and voluntary motion was recorded to a paralyzed knee using a single joint type HAL. These results suggest that polio survivors who have been paralyzed for a long time may improve their ability to control their neuromuscular system by using the proposed training method.%ポリオウイルスの感染によって運動神経の数が著しく減少してしまうと，脳から送られる電気信号が筋肉に届かず，極度の筋力低下や麻痺が起きる．感染者の内，1~2％の人々に弛級性麻痺が生じ，その麻痺が永久に残る場合もある．世界保健機関（WHO）は世界のポリオ経験者数は1000~2000万人と推定している．また，ポリオウイルス感染後，一時的に運動機能が回復しても，数十年後に突然四肢が麻痺するというポストポリオ症候群（PPS:Post Polic Syndrome）も報告されており，潜在的な麻痺予備軍の数は相当数に上ると考えられる．