Development of Gait-Training Orthosis with Water Hydraulic McKibben Muscles

This paper is concerned with development of water hydraulic gait-training orthosis. In particular, underwater gait-training is focused on, in order to reduce weight and some mechanism of gait-training orthosis. The proposed orthosis consists of McKibben muscles driven by tap water and rubber belts supporting human’s body weight. For this reason, the orthosis can easily be put on and off. In addition, the orthosis has enough flexibility. In this paper, two topics are examined; first, characteristics of water hydraulic McKibben muscle are shown by carrying out several experiments. Then two new estimation methods of joint angle are proposed, because the proposed orthosis cannot use any metallic frame and rigid-body sensor. In other words, we have to obtain the angle of hip joint without potentiometer. The one is the method using flex sensor and another is the method using dynamic model. As a result, both methods without potentiometer are verified by experiments and the affectivities of both methods are shown.