Designing and Creating a Prototype of Robotic Skeleton Systems for Computerized Lower Limb Prosthesis

Abstract

Recent statistics reveal that more than 40 million people of all ages from all over the world suffer amputations, and only 5% of them in need have access to assistive products. Common causes of amputation include congenital deformities, vascular diseases, diabetes, and accidents. A prosthesis is an assistive device that is used to substitute and restore the normal functions of the missing part of body. A prosthesis can be either functional or cosmetic, and can be either attached to the body externally or implanted surgically. Without prosthetic innovations, lower-limb amputees are required to have ordinary ambulatory skills sufficient to perform the basic movement functions and the ability to stand, walk, sit, reach with hands and arms, and manipulate (lift, carry, move) light to medium weights. Unfortunately, some amputees are unable even to stand and use their prosthesis to meet their demand. It has been found that traditional prostheses are mostly passive products with limitations and drawbacks. Recent research suggests that a trend in the utilization of active actuators/prostheses can overcome limitations and drawbacks of passive prostheses. Major functions of active prostheses are real-time intent recognitions, control strategies, torque requirements reduction, and energy saving. This paper presents the design of robotic skeletal system of the lower limb for computerized prosthetic leg development. The major structure of robotic skeletal systems consists of lower-limb joints modules, kinematics sensors and kinetics sensors. By taking advantage of the modern microprocessor-based controllers and low-power transmitters, the new robotic skeleton systems are created with better control performance in nearly real-time basis, lighter weight, higher flexibility, greater range of movement around a join, and better safety. The preliminary experiments are performed to evaluate the new design of robotic skeletal system by measuring sensors data while walking on ground, and climbing up-down stairs. Findings indicate the new design of a robotic skeletal system can provide the useful biomechanics parameters, which can be used for the development of computerized lower limb prosthesis.