Affiliations: [a] Instituto de Biomecánica de Valencia (IBV) Universidad Politécnica de Valencia, Camino de Vera s/n, 46022 Valencia, Spain | [b] Sociology University of Valencia, Universitat de València, Valencia, Spain | [c] Department of Anatomy and Human Embryology, Faculty of Medicine, Universitat de València, Valencia, Spain | [d] Universitat Jaume I, Castelló, Spain | [e] Centro de Automática y Robótica, CAR UPM-CSIC, Madrid, Spain | [f] Avapace, Asociación Valenciana de ayuda a la parálisis Cerebral, Valencia, Spain | [g] Grupo de Tecnología Sanitaria del IBV, CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Valencia, Spain
Correspondence:
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Corresponding author: Amparo López-Vicente, Sociology University of Valencia, Universitat de València, Valencia, Spain. E-mail:amparo.lopez@ibv.upv.es
Abstract: This study concerns the difficulty in accessing computers faced by people
with Dyskinetic Cerebral Palsy (DCP). Thus diminishing their opportunities
to communicate or learn. This population usually needs an alternative input
human-computer interface (HCI). The paper presents an alternative multimodal
HCI that incorporates a head-mounted interface and superficial
electromyography sensors (sEMG). The aim of the study is to assess the
usability and the suitability of these two HCI devices. Six non-disabled
subjects and ten subjects with DCP participated in the iterative process in
which each test follows an improvement of an input. The results indicated
that for both systems, the improvements in the usability are remarkable when
there were previous training programmes with both interfaces. These tests
allowed the identification of the main difficulties associated with
disability: poor control of the voluntary muscle contraction, which affects
the EMG signal, and abnormal postures, which affect the head-mounted
interface control. Regarding the EMG signal, the characterisation of the
involuntary patterns of muscle contractions may prevent false positives. In
the case of the inertial interface, a relative mode control (based on the
velocity of the movement instead of posture) may be a solution to increasing
the usability and task performance.
Keywords: Cerebral palsy, dyskinesia, usability, augmentative and alternative communication, human-machine interaction, assistive technology, user-adaptation, sEMG, inertial sensors, motor disorders
