Application of multibody dynamics techniques to active orthosis design for gait assistance

Abstract

Today, there is an urgent need for the healthcare world to be “re-engineered”, which necessarily means cooperation between physicians and engineers. Following this trend, biomechanics is becoming one of the most attractive fields to the mechanical research community. In this project, the expertise accumulated by the UDC group on multibody system dynamics is to be applied to the development of a computer tool aimed to simulate the gait of incomplete spinal cord injured subjects wearing active orthoses. Such a tool is expected to serve for the design or adaptation and testing of subject-tailored orthoses in the computer, so that patients are minimally disturbed. Due to the mentioned interdisciplinary character of the addressed field, the UDC group includes two physicians actively involved in the corresponding medical area, and is complemented by the UEX group, which has got experience on human motion analysis, and by the UPC group, which has carried out research on the dynamics and energetics of bipedal walking systems. The main challenges of the project are the development of a robust and efficient method to determine muscle effort during gait, the adequate modeling of the disability effect on muscle behavior, the simulation of the interaction between the orthosis actuation and the muscular response, the construction of an active orthosis prototype and the implementation of its controller. Provided the project is successful, the obtained computer tool could then be extended to gait disabilities due to other causes -like acquired brain damage, cerebral palsy or postpolio syndrome-, or to other types of assistive devices.