BACKGROUND: Despite important advancements in control and mechatronics of myoelectric prostheses, the communication between the user and his/her bionic limb is still unidirectional, as these systems do not provide somatosensory feedback. Electrotactile stimulation is an attractive technology to close the control loop since it allows flexible modulation of multiple parameters and compact interface design via multi-pad electrodes. However, the stimulation interferes with the recording of myoelectric signals and this can be detrimental to control. METHODS: We present a novel compact solution for simultaneous recording and stimulation through dynamic blanking of stimulation artefacts. To test the system, a feedback coding scheme communicating wrist rotation and hand aperture was developed specifically to stress the myoelectric control while still providing meaningful information to the subjects. Ten subjects participated in an experiment, where the quality of closed-loop myoelectric control was assessed by controlling a cursor in a two degrees of freedom target-reaching task. The benchmark performance with visual feedback was compared to that achieved by combining visual feedback and electrotactile stimulation as well as by using electrotactile feedback only. RESULTS: There was no significant difference in performance between visual and combined feedback condition with regards to successfully reached targets, time to reach a target, path efficiency and the number of overshoots. Therefore, the quality of myoelectric control was preserved in spite of the stimulation. As expected, the tactile condition was significantly poorer in completion rate (100/4% and 78/25% for combined and tactile condition, respectively) and time to reach a target (9/2 s and 13/4 s for combined and tactile condition, respectively). However, the performance in the tactile condition was still good, with no significant difference in path efficiency (38/8%) and the number of overshoots (0.5/0.4 overshoots), indicating that the stimulation was ...
A compact system for simultaneous stimulation and recording for closed-loop myoelectric control
2021-05-25
Garenfeld , M A , Jorgovanovic , N , Ilic , V , Strbac , M , Isakovic , M , Dideriksen , J L & Dosen , S 2021 , ' A compact system for simultaneous stimulation and recording for closed-loop myoelectric control ' , Journal of NeuroEngineering and Rehabilitation , vol. 18 , no. 1 , 87 . https://doi.org/10.1186/s12984-021-00877-5
Article (Journal)
Electronic Resource
English
DDC: | 629 |
Closed-loop multi-amplitude control for robust and dexterous performance of myoelectric prosthesis
BASE | 2020
|