To read this content please select one of the options below:

Design of a myoelectric prosthetic hand implementing postural synergy mechanically

Shunchong Li (State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China)
Xinjun Sheng (State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China)
Honghai Liu (State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China)
Xiangyang Zhu (State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China)

Industrial Robot

ISSN: 0143-991x

Article publication date: 12 August 2014

678

Abstract

Purpose

This paper aims to describe the design of a multi-degree of freedom (DOF) prosthetic hand prototype implementing postural synergy mechanically, which is actuated by two motors via a transmission unit, and is controlled using surface electromyography (sEMG) signal.

Design/methodology/approach

First, an anthropomorphic robotic hand is designed to imitate the human hand. The robotic hand has 18 DOF, 12 of which are actively driven by Bowden cables. Next, a set of different grasp modes are performed on a “full actuation” robotic hand, and principal component analysis (PCA) method is used to extract the first two postural synergies. Then, they are used to design a differential pulley-based transmission unit using two independent inputs to drive 12 output tendons. Finally, two control signals extracted from six channels of sEMG signals are used to proportionally control the two motors for achieving hand posture synthesis.

Findings

Using a differential pulley-based mechanical transmission unit to implement the synthesis of the first two postural synergies can make the prosthetic hand achieve different grasps by two motors, such as power, precision and lateral grasps. It is also feasible to control this “two actuation” prosthetic hand by relating the two-dimensional sEMG inputs with the first two postural synergies.

Originality/value

Mechanical implantation of postural synergies reduces the number of independent actuators without sacrificing the prosthetic hand’s versatility and simplifies its controller. Two-dimensional control extracted from sEMG is mapped into the combination coefficients of postural synergy synthesis. It shows potential application in the practical prosthetic hand.

Keywords

Acknowledgements

This work is supported by the National Basic Research Program (973 Program) of China (Grant No. 2011CB013305), the National Natural Science Foundation of China (Grant No. 51375296) and the Science and Technology Commission of Shanghai Municipality (Grant No. 13430721600).

Citation

Li, S., Sheng, X., Liu, H. and Zhu, X. (2014), "Design of a myoelectric prosthetic hand implementing postural synergy mechanically", Industrial Robot, Vol. 41 No. 5, pp. 447-455. https://doi.org/10.1108/IR-03-2014-0312

Publisher

:

Emerald Group Publishing Limited

Copyright © 2014, Emerald Group Publishing Limited

Related articles