Tactile and Slip Sensation Acquisition in Prosthetic Hands and Proprioceptive Feedback of Perception for Arm Amputees

Review Article

Phys Med Rehabil Int. 2015;2(2): 1032.

Tactile and Slip Sensation Acquisition in Prosthetic Hands and Proprioceptive Feedback of Perception for Arm Amputees

Fang P and Li G*

Key Laboratory of Human-Machine Intelligence Synergic Systems, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, China

*Corresponding author: Prof Li G, Key Laboratory of Human-Machine Intelligence Synergic Systems, Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Nanshan, Shenzhen, China

Received: January 10, 2015; Accepted: February 12, 2015 Published: February 13, 2015

Abstract


Prosthetic hands are expected by upper-limb amputees as useful tools to restore lost hand abilities. Possible real-time and intuitive perception of touching and slipping through prosthetic hands would help amputees a lot in daily activities. In this review paper, the results of several surveys on user demands were firstly summarized, indicating the importance of tactile and slip perception feedback for prosthesis users. A possible way to build artificial sensation in prosthetic hands is to develop one or more sensor systems that can detect sensation signals of, for example, touching and/or slipping. In the second part of this paper, different sensing techniques for tactile and slip signal acquisition, which were especially investigated for the application in prosthetic hands, were reviewed. To transfer the sensor-detected sensation signals into users’ nerve systems is very critical to realize a proprioceptive feedback of perception for amputees. The final part of the paper introduced some possible perception feedback modalities. Stimulations on residual limb surface, such as vibration, temperature, and pressure, are low-cost and easy to realize, but usually considered as distracting and still unintuitive. A direct neural interface may provide intuitive and accurate perception feedback. Electrical stimulations of both somatosensory cortex and peripheral never are possible approaches to regenerate perception feedback for limb amputees. But more research work and clinical verification should be performed before an actual application.

Keywords: Prosthetic hand; Limb amputee; Sensation; Perception; Feedback

Introduction

Dexterous prosthetic arms would be always necessary and expected for upper-limb amputees to restore their lost arm/hand functions. In order to improve the control performance of multifunctional prostheses, several control methods have been proposed and realized by using different neural signals related to motor commands, such as surface electromyogram (sEMG) [1], brain-computer interface (BCI) [2], peripheral nerve interface (PNI) [3], targeted muscle reinnervation (TMR) [4], etc. In addition, some control strategies based on fusion of multisource information have also been suggested and investigated [5]. For upper-limb amputees, an intuitive and real-time perception of external environments through their prostheses would be very helpful to enhance the prosthesis operation safety and satisfaction [6]. Up to now, however, almost all the commercially available prosthetic hands do not have this kind of sensation function, and they usually are operated only with a visual feedback. Thus users have to pay considerable concentration on the actions of their prosthetic hands and estimate the operation condition by means of eye observation, which is much less natural and cumbersome [7]. Without a proper feedback of tactile and slip perception, an “over-grasp” may occur where an object in hand may be deformed or damaged, or an “undergrasp” may occur where the object may slip down from hand. A basic schematic diagram of possible closed-loop control with perception feedback for prostheses is presented in Figure 1.

Citation: Fang P and Li G. Tactile and Slip Sensation Acquisition in Prosthetic Hands and Proprioceptive Feedback of Perception for Arm Amputees. Phys Med Rehabil Int. 2015;2(2): 1032. ISSN:2471-0377