Wearable Technology to Enable Independent Wayfinding for People with Visual Impairment
Creators: name: Son, Hojun
Publisher: name: My University
Year: 2022
Subjects: subject: Wearable Technology to Enable Independent Wayfinding for People with Visual Impairment
subject: Biomedical Engineering
subject: FOS: Medical engineering
subject: Engineering

description: A smart wearable system can provide significant benefits to people with visual impairment to improve their quality of life. There are more than 7,500,000 people with a visual disability in the United State and they face challenges regularly. In particular, a difficult problem for people with visual impairment is wayfinding. Wayfinding provides independence and is important with respect to the quality of life and the equity of opportunity. Numerous studies have researched the topic to identify technology for independent traveling for people with visual impairment. However, previous studies have suggested partial solutions due to limitations in resources like computing devices. I propose a smart wearable system to process all difficult tasks typically performed by vision during wayfinding and provide non-visual guidance cues to direct motion. As a test case for wayfinding, I choose a street crossing at a signalized crosswalk. This is a challenging task without vision. Initially, I reprogrammed a commercial smart-glasses system to classify a crosswalk sign and localize the user based on the location of the sign. Two study participants with visual impairment were able to use this system to successfully cross the street, but the system has constraints such as loss of tracked signs for user localization and initial independent alignment. To improve the smart wearable system, I created a prior map which is like a high-density map for autonomous vehicles at the defined intersection where we conducted human subject experiments. To estimate user position on the prior map, I created a semantic segmentation network running in real-time on the resources available with a portable computing device. Proper positioning on the map enabled people with visual impairment to align independently toward destinations. Including a wider field of view camera and real-time simultaneous localization and mapping algorithm allowed reliable position estimation while they crossed the street, with verbal cues to guide their motion. Three blind test subjects used the system to cross a real crosswalk with an average percent preferred walking speed of 94.75%. To evaluate different feedback methods, I built a system to measure the reactions of people with visual impairment while wayfinding with variable types of feedback. The feedback methods contain verbal, vibrotactile, and a combination of both. In addition to these feedback, artificial visual feedback through Argus 2 is included. I expect that our research can be helpful to design optimal feedback for wayfinding. The prototype wearable system supports the idea that people with visually impairment can be integrated with extensive systems for autonomous vehicles using developed technologies without redundant and complex requirements such as a separate map only for people with visual impairment. Dynamic environments must be considered to improve the system, but sighted people typically yield their path to a pedestrian with visual impairment, thus focusing first on static objects can still provide significant benefit. Soon, a wearable electronic aid can be a bridge between people with visual impairment and a vast information infrastructure for autonomous systems, and this will increase the quality of life for people with visual impairment.