Virtual Reality Impact on Powered Mobility: a Feasibility Study

This outcome assesses the capability of using the VR-PMP (Virtual Reality-Powered Mobility Program) simulator by observing dropout rates, from 0 participant to 10 participants due to technology issues (e.g., equipment usability, motion sickness), as well as satisfaction levels with VR (Virtual Reality) hardware and software.

The Powered Mobility Program (PMP) score assesses assistance, supervision, and autonomy in driving powered wheelchairs through 34 tasks. These tasks are categorized into basic skills, structured environment driving, and unstructured environment driving domains. Each task is scored from 0 (task not attempted) to 5 (age-appropriate supervision), with a maximum total score of 170 points. The total score is calculated by summing individual item scores and dividing by the number of completed tasks.

The QUEST 2.0 questionnaire score is an outcome measurement that evaluates user's satisfaction with their assistive device. It is used to document the real-life benefits of assistive devices and justify their necessity. It comprises 12 items divided into two parts: Device (8 items) and Services (4 items). Each item is rated on a 5-point scale from 1 ("not satisfied at all") to 5 ("very satisfied"). The total score is the sum of valid item scores divided by the number of valid items.

The MSAQ questionnaire assesses motion sickness. It consists of 16 questions divided into four subcategories: Gastrointestinal (G), Central (C), Peripheral (P), and Sopite-related (S). Responses are scored on a scale from 1 to 9 points. Each subcategory is scored individually, contributing to a total score ranging from 11 to 144 points. The overall motion sickness score is calculated as the percentage of total points scored: (sum of all item points / 144) × 100. Subscale scores are calculated similarly as percentages within each factor: (sum of gastrointestinal items / 36) × 100; (sum of central items / 45) × 100; (sum of peripheral items / 27) × 100; (sum of sopite items / 36) × 100.

The IPQ questionnaire assesses sense of presence (SOP - level of immersion in VR) of a VR user. The IPQ consists of 14 items divided into four subcategories: spatial presence, involvement, perceived realism level, and a "sense of being present." All items are rated on a seven-point scale (0-6), with a higher score indicating greater SOP. The total score is obtained by summing the scores of individual items (from 0 to 84 points).

The NASA-TLX questionnaire score (National Aeronautics and Space Administration Task Load Index) measures physical and mental workload using six items related to mental load, physical activity, speed of performance, performance, effort, and frustration. Each item is accompanied by a 12 cm line scale divided into 20 equal intervals, anchored by binary descriptors (e.g., low/high), delimited by 21 vertical markers, and then converted to a scale from 0 to 100 points. To calculate the score for each scale, the number of lines marked by a participant is counted, 1 is subtracted, and the result is multiplied by 5. Weights from 0-5 will be assigned to the 15 subscale comparisons, which will be multiplied by the corresponding subscale score. The total score (from 0 to 100 points) is estimated by summing the weighted scores and dividing by 15.

Participants will be asked to fill out a modified version of the NASA-TLX (mNASA-TLX), using the same questions but with a different scale ranging from 1 (low) to 5 (high). The scores will be then converted using the 0-100 points scale, as for the NASA-TLX.

The GDQ is a questionnaire to evaluate the user's satisfaction of the VR-PMP simulator. It assesses the usability of the graphical interface and user preferences (measured on a scale from 1 to 9 points) regarding colors, game animation, and avatars used. The total score is estimated by averaging the items.