Evaluation of Electrotactile Feedback Schemes in a Closed-Loop Myoelectric Prosthesis
Authors
Garenfeld, Martin Alexander ; Mortensen, Christian Korfitz
Term
4. term
Publication year
2019
Submitted on
2019-06-06
Pages
67
Abstract
This thesis examines how electrotactile feedback can provide intuitive proprioceptive information about a myoelectric prosthesis’ position, reducing reliance on vision. Two compact feedback schemes were developed and tested in a simulated closed‑loop prosthesis: a spatial scheme that varied activation of electrode pads around the forearm, and an amplitude‑based scheme that modulated stimulation strength from selected pads. Both schemes conveyed two degrees of freedom (wrist rotation and hand aperture) in five discrete intervals. Fourteen able‑bodied participants completed a Fitts’ Law–inspired target‑reaching task after brief training, with randomized scheme order. The amplitude scheme achieved a higher completion rate (93% ± 6%) than the spatial scheme (87% ± 11%, p = 0.044) and was preferred by 64% of participants; visual feedback yielded higher performance (99% ± 2%, p < 0.001). The high completion rates and positive subjective ratings indicate that both schemes are intuitive, easy to understand, and can simultaneously convey two feedback variables via a compact stimulation interface, supporting practical integration in future prostheses.
Denne afhandling undersøger, hvordan elektrotaktil feedback kan give intuitiv proprioceptiv information om en myoelektrisk proteses stilling og dermed mindske behovet for synskontrol. To kompakte feedbackskemaer blev udviklet og testet i en simuleret lukket‑loop protese: et spatialt skema, der varierede aktivering af elektrodepuder omkring underarmen, og et amplitudebaseret skema, der modulerede stimuleringens styrke fra udvalgte puder. Begge skemaer formidlede to frihedsgrader (håndrotation og håndåbning) i fem diskrete intervaller. Fjorten raske forsøgspersoner gennemførte en Fitts’ Law‑inspireret målrammeopgave efter kort træning, med randomiseret rækkefølge af skemaer. Amplitudeskemaet gav en højere succesrate (93 % ± 6 %) end det spatiale (87 % ± 11 %, p = 0.044) og blev foretrukket af 64 % af deltagerne; visuelt feedback gav højere succes (99 % ± 2 %, p < 0.001). De høje succesrater og positive subjektive vurderinger tyder på, at begge skemaer er intuitive, lette at forstå og kan samtidig formidle to feedbackvariable via et kompakt stimuleringsinterface, hvilket understøtter praktisk integration i en fremtidig protese.
[This apstract has been generated with the help of AI directly from the project full text]
Keywords