smarthmd for improved mobility

Conditions: Low Vision; Orientation; Mobility Limitation; Navigation, Spatial; Visual Impairment

Summary: the national eye institute estimated about 3 million people over age 40 in the us had low vision in 2010 and projects an increase to nearly 5 million in 2030 and 9 million in 2050. current assistive technologies are a patchwork of mostly low-technology aids with limited capabilities that are often difficult to use, and are not widely adopted. this shortfall in capabilities of assistive technology often stems from lack of a user-centered design approach and is a critical barrier to improve the everyday activities of life (edal) and the quality of life (qol) for individuals with low vision. an intuitive head mounted display (hmd) system on enhancing orientation and mobility (o\&m) and crosswalk navigation, could improve independence, potentially decrease falls, and improve edal and qol. the central hypothesis is that an electronic navigation system incorporating computer vision will enhance o\&m for individuals with low vision. the goal is to develop and validate a smarthmd by incorporating advanced computer vision algorithms and flexible user interfaces that can be precisely tailored to an individual's o\&m need. this project will address the specific question of mobility while the subject crosses a street at a signaled crosswalk. this is a dangerous and difficult task for visually impaired patients and a significant barrier to independent mobility.

this study was originally intended as a single-arm study. early results and unanticipated events related to component availability made it clear that multiple configurations of the device would be necessary to produce a functional device. therefore, the study was split into multiple cohorts representing each iteration of the device and testing process, as follows: as the trial progressed, the participants recruited were consistently unable to perform tasks without smarthmd. this is due to the recruitment of participants with severe vision loss. due to this finding, data was only acquired when participants used the smarthmd when active instead of collecting data with and without the system being active. the participants performed a subset of experiments due to time constraints. some performed only outdoor trials; some performed only indoor trials; others performed both. the outcome measures depend on which experiments were performed. after the first test involving the initial three participants, the odg system became unsupported by the company that produced the device. in response, the study team developed a prototype system (rgbd), which was used in the odg system's place for the remaining tests. the rgbd was initially used indoors with laptop and subsequently outdoors with mobile hardware and new software.

Eligibility criteria:
inclusion criteria: * diagnosed with low vision * self reported difficulty with mobility and finding doors (either indoors or outdoors) and using signalized crosswalks. * ability to cooperate for tests * able to participate in all visits exclusion criteria: * unable to use head mounted display technology * unstable age-related macular degeneration within the past 3 months * unstable diabetic retinopathy within the past 3 months * unstable diabetes within the past 3 months * ocular infection or ocular inflammation in the past 3 months * ocular trauma within the past 6 months * intraocular surgery within 6 months * optical coherence tomography retinal findings of concern to investigator for unstable vision during the study * women who are pregnant (due to risk of falls and change in gait). * uncontrolled seizure disorder in the past 6 months * cerebrovascular accident occurring in the past 6 months * parkinson disease or neurological condition that limits mobility * alzheimer disease or other forms of dementia * conditions of concern to investigator that would confound orientation and mobility, such as severe arthritis, pain that limits ambulatory activities, or orthopedic surgery (e.g., hand, arm, shoulder, knee, or hip surgery within 12 months)