Automated Orientation & Mobility Training in Virtual Reality for Low Vision Rehabilitation

The human subject research is a randomized, controlled training trial that tests the effectiveness of three Virtual Reality-based Intelligent Orientation and Mobility Specialists (VR-IOMSs) in teaching orientation and mobility (O&M) task skills to individuals with low vision (LV). It will be conducted on two sites, University of Alabama at Birmingham (UAB) and Alabama Institute for Deaf and Blind (AIDB). The same protocol will be used on both sites. UAB will be the sIRB for the trial.

Three O&M tasks will be studied, timing to cross a signalized street using the near lane parallel traffic surge skill (Task NLPT), timing to cross an uncontrolled street using the traffic gap judgment skill (Task TGJ) and learning outdoor numbering system (Task ONS). A VR-IOMS will be developed and validated for each task. The training does not involve research subjects walking into street traffic.

Low vision subjects who have difficulties with these O&M tasks due to their impaired vision will be recruited from UAB and AIDB according to procedures approved by UAB IRB. Specifically, clinicians of UAB Center for Low Vision Rehabilitation will identify potential study subjects from records of existing patients and from new patient population. Recruitment letters from the clinicians will be sent to potential subjects. Patients who are interested in participating will initiate contact with UAB research team for initial evaluation and scheduling an enrollment visit. Certified O&M specialist (COMS) faculty of AIDB's School for the Blind, the Gentry Facility and Alabama Freedom Center for the Blind will identify potential study subjects from new students/clients and will use a recruitment script to inform them about the study. Students/clients who are interested will contact the AIDB team to arrange initial evaluation and enrollment session.

Initial evaluation includes inquiries of visual and hearing impairment, mental status and O&M training history. Potential subjects who pass the initial evaluation will attend an enrollment session where demographic information will be collect, visual and hearing functions will be assessed, if necessary and functional vision and ability to perform the study O&M tasks will be evaluated by COMS on real streets. Informed consent/assent material approved by UAB IRB will be presented to potential subjects who meet the inclusion criteria and/or their legally authorized representatives. Research activity will not begin until written informed consent/assent is obtained according to approved procedure.

Enrolled subjects will be randomized into three groups, learning the task from a VR-IOMS (experimental group), from a human COMS in real streets (active control group) and not learning the task but spending the same amount of time watching LV education videos (placebo group). All subjects will be evaluated by COMSs in real streets around the two study sites before training (pre-training), within 3 days after the completion of training (post-training) and 3 months after the completion of training (follow up). Their ability to perform the O&M tasks in real streets will be assessed quantitatively using objective methods. Specifically, in Task NLPT, the performance is measured by a safety score, which is determined by the time of the onset of the steady pedestrian WALK signal, the time when the first straight going car in the same direction as the traveler's crossing direction entering the street intersection and the time when the subject decides to start crossing (say GO). These times will be measured by the COMS using a stopwatch. The safety score, ranges from 0 to 1, represents the proportion of the duration of the pedestrian phase after the subject says GO. A larger score indicate a larger portion of pedestrian phase is available for the subject to walk across the street and is thus safer. A GO call in the steady DON'T WALK phase will be recorded as a negative number and is unsafe. This safety score was developed and used in the investigators' pilot research. The rule of thumb used by COMSs, start crossing within 7 seconds after the onset of the pedestrian WALK signal, will also be used. In Task TGJ, the performance is measured by a safety margin, which is the traffic gap width in seconds (the time interval in seconds between the first and second car passing in front of the traveler) minus the delay of the subject's crossing decision (say GO) and minus the time needed for the subject to walk across the street at the participant's preferred walking speed. Validated objective methods to measure the three times involved in safety margin determination have been used in previous studies of low vision patient TGJ performance and will be used in this research. A positive safety margin represents the time left of the traffic gap when the subject has reached the opposite side of the road, thus indicates a safe crossing decision. A negative safety margin represents the time when the subject is still in the road after the traffic gap has closed. It indicates an exposure of the subject to the traffic and thus indicates an unsafe decision. In Task ONS, the performance is measured by the correctness of the subject's plan to reach a destination in the neighborhood. The subject earns two points for making no error in the direction and the side of street of the destination, earns 1 point for getting one wrong and earns no point for getting both wrong. The subject will not walk into the traffic in any of the task evaluations in real streets.