JMIR Publications

ABSTRACT

Background:

People suffering from motor impairment often rely on Augmentative and Alternative Communication and/or environmental control systems controlled by screen-based eye-tracking devices. These systems suffer from many limitations, such as: bulkiness, poor portability and susceptibility to movement-related calibration errors. Mixed Reality (MR) technologies are a potential alternative, offering hands-free interfaces that can adapt to dynamic daily environments.

Objective:

The objective of the current study is to develop and evaluate, among people with motor and communication impairments, the usability and acceptability of a human-centred MR-AAC and environmental control system, operated via eye-tracking on a Microsoft HoloLens 2.

Methods:

The application has been iteratively developed using Universal Design and Design4All principles, including two focus groups with assistive technology experts. A pilot study has been conducted on 12 adults who had been using an AAC or environmental control system for at least three months. Participants had to navigate holographic grids to compose sentences and control a smart home in a single session of 90 minutes. The outcomes were assessed through the Individual Prioritized Problems Assessment (IPPA), the Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), the System Usability Scale (SUS), and an ad-hoc feedback questionnaire.

Results:

10 out of 12 participants completed the protocol, while 2 were excluded due to failure of the calibration procedure. Most tasks were completed within 15s. The SUS yielded a median score of 50 (IQR: 36–62), reflecting a moderate and variable perceived usability. QUEST scores averaged 2.95 out of 5, indicating moderate satisfaction. IPPA scores showed a median improvement of 1.8 (IQR: 0.75–5.1) with great variability. Holographic element visibility received high ratings with a mean of 4.5 out of 5, while ease of gaze selection had a lower score with a mean or 2.7out of 5. Key issues included eye strain, device overheating, and cognitive load from multi-level grid navigation.

Conclusions:

The current study proves the technical feasibility and clinical relevance of an AAC and environmental control system developed in MR. Despite some limitations like a small sample size, the participants appreciated the visual clarity of the holograms, innovativeness of the solution and integration of communication and smart home control. Future iterations should address selection accuracy, device comfort, and include longitudinal evaluations.