Multichannel electrotactile feedback with spatial and mixed coding for closed-loop control of grasping force in hand prostheses
Author(s)
Type
Journal Article
Abstract
Providing somatosensory feedback to the user of a myoelectric prosthesis is an important goal since it can improve the utility as well as facilitate the embodiment of the assistive system. Most often, the grasping force was selected as the feedback variable and communicated through one or more individual single channel stimulation units (e.g., electrodes, vibration motors). In the present study, an integrated, compact, multichannel solution comprising an array electrode and a programmable stimulator was presented. Two co ding schemes (15 levels), spatial and mixed (spatial and frequency) modulation, were tested in able-bodied subjects, psychometrically and in force control with routine grasping and force tracking using real and simulated prosthesis. The results demonstrated that mixed and spatial coding, although substantially different in psychometric tests, resulted in a similar performance during both force control tasks. Furthermore, the ideal, visual feedback was not better than the tactile feedback in routine grasping. To explain the observed results, a conceptual model was proposed emphasizing that the performance depends on multiple factors, including feedback uncertainty, nature of the task and the reliability of the feedforward control. The study outcomes, specific conclusions and the general model, are relevant for the design of closed-loop myoelectric prostheses utilizing tactile feedback.
Date Issued
2016-04-07
Date Acceptance
2016-02-29
Citation
IEEE Transactions on Neural Systems and Rehabilitation Engineering, 2016, 25 (3), pp.183-195
ISSN
1534-4320
Start Page
183
End Page
195
Journal / Book Title
IEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume
25
Issue
3
Copyright Statement
© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
Subjects
0903 Biomedical Engineering
0906 Electrical And Electronic Engineering
Biomedical Engineering
Publication Status
Published