Experimental Testing of a Prototype of an Active Elbow Orthosis Based on in vivo Investigation of Elbow Flexion/Extension of Healthy Subjects

• Published in: Bioautomation Vol. 26; no. 2; pp. 161 - 174
• Main Authors: Angelova, Silvija, Petrov, Emil, Raykov, Plamen, Raikova, Rositsa
• Format: Journal Article
• Language: English
• Published: Sophia Bulgarska Akademiya na Naukite / Bulgarian Academy of Sciences 01.06.2022; Bulgarian Academy of Sciences
• Subjects: active orthosis; Elbow; Experiments; flexion/extension; human experiments; Patients; Power; Rehabilitation; Robotics; Trauma; Velocity
• ISSN: 1314-1902; 1314-2321
• DOI: 10.7546/ijba.2022.26.2.000865

Many people have problems with elbow joint driving because of different diseases, sport trauma, road traffic injuries, etc. A good way for restoring elbow motions is a self-rehabilitation using an active orthosis. It has to be light, convenient for daily use, active, easy to control by patients, and safe. The paper presents a prototype of an active elbow orthosis. The plastic details were designed using a CAD system and were 3D printed. The joint was driven by a Dynamixel actuator. To increase the joint moment, a reduction gear-belt drive was constructed and applied. Experiments with six healthy subjects were performed using a Noraxon measuring system, aiming to investigate elbow joint angles in natural movements with four different velocities of elbow flexion and extension without and with a load of 0.5 kg in the hand. The four velocities (from very slow to very fast) were controlled by a specialized PC application. In order to achieve similar motions of the orthosis, the angle profiles were approximated so that the motion was between 10° and 120° because of electro/mechanical and software safety stoppers. Experiments were performed with the orthosis following the given angle profile without load and with a load of 0.5 kg. The results show that the orthosis’ forearm performs the given angle and angular speed profiles with enough precision.