This case study is based on a gentleman named Stan who was in a motorbike accident more than 6 years ago. The accident left him with no movement, function or feeling in his left arm, from the shoulder down. Doctors were not able to reconnect the nerve endings that connected to his left arm, due to their severity of damage. However they were able to connect these nerves to his diaphragm allowing him on inhalation to automatically lift his arm upwards. However for Stan to hold his arm up, he has to hold his breath for long durations, proving impractical for daily use or movement.

 

The end goal for the exoskeleton arm is to be 3D printed in ABS plastic as this proves to be the most cost effective, affordable, lightweight, customisable and hardier for daily use and wear. 3D printing will also make it easier and affordable for maintenance and replacment of parts. Having started the exoskeleton, the main focus currently is restoring the correct and appropriate range of movement for the elbow. Restoring the movement alone however is not enough, having looked at mechanisms to duplicate into the design, a ratchet strap mechanism proved to be the most appropriate. The ratchet strap was re-fabricated and modified to not only give the arm up and down motion, but to also lock in at certain points in the range of motion, allowing Stan to now hold his arm up effortlessly. A release mechanism was also attached to the ratchet fabricated elbow joint, to allow the arm to release back to resting.

 

Now having basic measurements of the arm and a working prototype for the elbow, the next stage and development begins converting it into 3D modeled data. New and extra components will be added and tested to achieve a whole working exoskeleton arm for Stan. This will be practical, customisable, cost effective and most importantly enable him to not only feel capable but achieve daily tasks which were once physically impossible.