Abstract

A prosthetic device aims to improve an amputee’s ability to perform activities of daily living, by mimicking the function of a biological arm. The use of a prosthesis has also been shown to minimise some of the issues facing amputees, such as poor posture and muscular skeletal pain. Active, myoelectric-controlled prosthetic arms have primarily focused on adults, despite evidence showing the benefits of early adoption in reducing the rejection rates and aiding in proper motor neural development.

This work presents SIMPA, a low-cost 3D-printed prosthetic arm with a soft-gripper based end device. The arm has been designed using CAD and 3D-scaning and manufactured using predominantly 3Dprinting techniques. This all serves the aim of reducing cost and lead-time, both crucial aspects for prosthetic manufacturing, particularly with the rapid growth rates of young children.

A voluntary opening control system utilising an armband based (surface electromyography) sEMG has been developed concurrently. This simple control system acts as a base for more advanced control structures as the child develops. Grasp tests have resulted in an average effectiveness of 87%, with objects in excess of 400g being securely grasped. Force tests have shown that the arm is performing in line with current adult prosthetic devices. The results highlight the effectiveness of soft grippers as an end device in prosthetics, as well as viability of toddler-scale 3D-printed myoelectric devices.