Continuous passive motion-based rehabilitation equipment for the recovery of lower limb bearing joints

Applying continuous passive rehabilitation movements as part of the recovery programme of patients with post-traumatic disabilities of the bearing joints of the lower limbs requires the development of new high performance equipment. The proposed equipment is designed to be deployed in rehabilitation medical care, its specific objectives being maintenance and recovery of body functions, prevention of dysfunctions, using in this respect kinetic and orthotic techniques, as well as various supporting and adaptive accessories. This paper presents a variant of rehabilitation equipment the novelty of which consists in the utilisation of compliant (soft) fluidic actuators of linear type and variable stiffness. The proposed rehabilitation equipment benefits from a cost efficient, simple and robust construction, being easy to use by persons affected by dysfunctions of the bearing joints. By deploying compliant (soft) actuators, which allow slight deviations from the given position, the human-machine interaction can occur in a gentle and more comfortable manner. This paper presents cinematic and dynamic modelling of the proposed rehabilitation equipment, highlighting its advantages compared to equipments endowed with electric-mechanical linkages.