Yoshikawa Dan, Kawamoto Hiroaki, Sankai Yoshiyuki
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:4941-4946. doi: 10.1109/EMBC44109.2020.9176179.
Thumb movement is very important for object gripping. However, when a cerebrovascular disorder or spinal cord injury causes hand paralysis, which impairs the motor function of the fingers, it becomes impossible to flex and extend the fingers and to move the thumb to the opposition position; this makes it difficult to grip objects in daily life. Several assistive devices have been developed for people with hand paralysis. However, they only assist flexion/extension of the thumb, narrow the type of grip by fixing the thumb position, or have large sizes and weights due to using links and frames to assist thumb adduction and opposition. They are not effective for daily use. Thumb motion assistance that does not hinder the degree of freedom of the thumb is important for gripping objects in everyday life. In this study, we developed a wearable ring and a fingertip-cap that assist two-degree-of-freedom thumb motion by means of a tendon-drive based on the hand's anatomy; the feasibility of the device is confirmed through basic experiments, in which the device was evaluated by a hand in a weakened state. It was confirmed that opposing movement and flexion/extension motion of the thumb were possible. In addition, we confirmed that it was possible to grip thin objects by using only thumb motion assistance. In conclusion, we developed a tendon-driven thumb motion assistive device using a ring-shaped component and confirmed the feasibility of this system to support the opposition/reposition and flexion/extension motions of the thumb.
拇指运动对于抓握物体非常重要。然而，当脑血管疾病或脊髓损伤导致手部麻痹，从而损害手指的运动功能时，手指就无法屈伸，拇指也无法移动到对掌位置；这使得在日常生活中抓握物体变得困难。已经为手部麻痹患者开发了几种辅助装置。然而，它们只能辅助拇指的屈伸，通过固定拇指位置来缩小抓握类型，或者由于使用连杆和框架来辅助拇指内收和对掌而尺寸和重量较大。它们在日常使用中效果不佳。不妨碍拇指自由度的拇指运动辅助对于日常生活中的抓握物体很重要。在本研究中，我们基于手部解剖结构开发了一种可穿戴指环和指尖帽，通过肌腱驱动辅助拇指的两自由度运动；通过基础实验证实了该装置的可行性，在实验中用处于虚弱状态的手对该装置进行了评估。证实了拇指的对掌运动和屈伸运动是可行的。此外，我们证实仅使用拇指运动辅助就可以抓握薄物体。总之，我们开发了一种使用环形部件的肌腱驱动拇指运动辅助装置，并证实了该系统支持拇指对掌/复位和屈伸运动的可行性。
