2023-02-15 ジョージア工科大学
◆人間のバランスは複雑なダンスであり、最先端のロボットやロボット型外骨格のようなウェアラブルでさえ、人間の脳と身体がどのように連携して直立しているかを再現するのは困難である。ジョージア工科大学とエモリー大学の研究者による新しい研究は、バランスの問題に取り組むための第一歩を踏み出すものです。
◆2月15日にScience Robotics誌に掲載された論文で、研究グループは、足首の外骨格がバランスを改善するためには、我々の身体よりも速く反応する必要があることを示した。参加者は、脚と足首の筋肉がバランスを回復するために活動するのと同じ時間まで、外骨格が力を加えるのを遅らせた場合、それ以上早く回復することはありませんでした。
<関連情報>
- https://research.gatech.edu/help-recover-balance-robotic-exoskeletons-have-be-faster-human-reflexes
- https://coe.gatech.edu/news/2023/02/help-recover-balance-robotic-exoskeletons-have-be-faster-human-reflexes
- https://www.science.org/doi/10.1126/scirobotics.adf1080
外骨格は、立位バランスを改善するために、生理的反応より速く反応する必要がある Exoskeletons need to react faster than physiological responses to improve standing balance
Owen N. Beck,Max K. Shepherd,Rish Rastogi,Giovanni Martino,Lena H. Ting,Gregory S. Sawicki
Science Robotics Published:15 Feb 2023
DOI:https://doi.org/10.1126/scirobotics.adf1080
Abstract
Maintaining balance throughout daily activities is challenging because of the unstable nature of the human body. For instance, a person’s delayed reaction times limit their ability to restore balance after disturbances. Wearable exoskeletons have the potential to enhance user balance after a disturbance by reacting faster than physiologically possible. However, “artificially fast” balance-correcting exoskeleton torque may interfere with the user’s ensuing physiological responses, consequently hindering the overall reactive balance response. Here, we show that exoskeletons need to react faster than physiological responses to improve standing balance after postural perturbations. Delivering ankle exoskeleton torque before the onset of physiological reactive joint moments improved standing balance by 9%, whereas delaying torque onset to coincide with that of physiological reactive ankle moments did not. In addition, artificially fast exoskeleton torque disrupted the ankle mechanics that generate initial local sensory feedback, but the initial reactive soleus muscle activity was only reduced by 18% versus baseline. More variance of the initial reactive soleus muscle activity was accounted for using delayed and scaled whole-body mechanics [specifically center of mass (CoM) velocity] versus local ankle—or soleus fascicle—mechanics, supporting the notion that reactive muscle activity is commanded to achieve task-level goals, such as maintaining balance. Together, to elicit symbiotic human-exoskeleton balance control, device torque may need to be informed by mechanical estimates of global sensory feedback, such as CoM kinematics, that precede physiological responses.
