Study of the Different Types of Actuators and Mechanisms for Upper Limb Prostheses

Abstract

Research in the area of actuators and mechanisms has shown steadily growing technological advances in externally activated upper limb prostheses. From among the actuators, advances include the use of piezoelectric materials, special metal alloys, polymers, and new motor applications, while the advances in mechanisms include mechanical designs based on the anatomy of the human hand and improvements in the way these components are combined. These efforts are aimed at meeting the need for anthropomorphic and functional prosthetic devices that enable patients to carry out basic daily tasks more easily and reduce the rejection rate of prostheses. This article technically discusses the several types of actuators and mechanisms, listing their main characteristics, applications, and advantages and disadvantages, and the current state of research in the area of rehabilitation of upper limb functions through the use of active prostheses. Comparisons of these devices are made with regard to the main criteria of construction and operation required to achieve optimal prosthetic performance.

The Developments of piezoelectric Materials and Shape Memory Alloys in Robotic Actuator Systems

“…These actuators have a small size and low mass density. Moreover, since they have a high range of power density and they have a high torque (Cura et al, 2003), therefore they have plenty of technological applications in automotive, aerospace, and biological and medical purposes. They are one of the best-known actuators for robotic systems because they have high bandwidth, high power density and ability to operate on direct current (DC) without need for lubrication or cooling.…”

Artificial Organs 2003: A Year in Review

“…Vanderlei O. Del Cura et al of the University of São Paulo at São Carlos reviewed the various types of actuators and mechanisms for upper limb prostheses (149). The diversity of the technology and operating principles reveal a high potential for improving and developing new designs to meet clinical needs.…”

Mechanical design of an anthropomorphic prosthetic hand for shape memory alloy actuation

“…A comprehensive review of the mechanisms and actuators used in prosthetic hands still in the research phase was published by Del Cura et al [1]. Anthropomorphic designs, which follow human anatomy, provide more natural prehension (grip) patterns.…”

“…These have articulated fingers and hence more DOF. A system of cables (tendons) and actuators is used to cause finger flexion [1]. The problem with increasing the DOF is the need for more control inputs if each DOF is to be separately controlled.…”

“…Several different types of actuators have been used in prosthetic applications. These include motors, hydraulic actuators, piezoelectric actuators, shape memory alloys (SMA) and contractile polymer gels [1]. SMA wires have the ability to contract when heated (activated) and thus are sometimes called artificial muscles.…”