A Biomedical Engineering Approach to Select an Appropriate Upper Limb Prosthesis

Abstract

The loss of a hand or arm is physically and emotionally devastating.  The amputees must learn to perform activities of daily living (ADL) and job-related activities with the aid of a prosthesis.  Upper limb prostheses are divided into two main control types: body-powered and externally powered.  The most common interface for externally-powered prostheses utilizes the electromyogram (EMG) as a signal. This type of device is called myoelectric prosthesis.

The fitting process of an upper-limb prosthetic device onto an amputee is not straight forward. The device has to be well-fit, comfortable, and easy-to-use for the ADL and work. Myoelectric prostheses tend to be the first choice of many but they are not suitable for all type of amputations. Therefore, the objective of this study is to assess whether an amputee should be fitted with a body-powered or myoelectric prosthesis.

The study started with a survey of the local prosthetists to identify the key factors for fitting upper-limb amputees. The factors will be used to develop criteria for favoring either bodypowered or myoelectric devices. Then, selected engineering measurements of terminal devices such as grip force and slip can be obtained for body-powered and myoelectric prostheses. Then, a prescription process can be developed by using the criteria with the right type of prosthesis to achieve the amputee’s vocational, recreational and psychosocial requirements.