A New Design of Active Lower Limb Orthosis with One Degree of Freedom for Paraplegia

Abstract

This paper has proposed a new design of active lower limb orthosis which is called as oneDHALO (one-actuator Drive Hip and Ankle Linked Orthosis). The oneDHALO has a linking mechanism which connects both ankle joints with a medial hip joint and an actuator which drives the rotation angle. The joints linkage mechanism keeps feet always in parallel with the floor to avoid stumbling and assists swinging of the leg. In addition, one servo motor has been introduced to assist and control the movement constrained by the mechanism. To match the active movement to walking phase, optical sensors have been introduced at soles of the feet. The control device which consists of internal communication system, sensor interfaces and a single board computer (Raspberry Pi) is designed for all in one with the mechanical part of the orthosis. This presentation reveals the preliminary experimental results of the system to show the good points of the design.