Behavior Verification of a Smartphone-Based Fall Risk Alert System and Visually Impaired Users on a Station Platform

We have been working on a system that alerts visually impaired people who get closer to fall risk areas, such as platform edges and stairs, in their walking direction to reduce accidental falls. This system, known as electronic travel aid (ETA), is usually attached to a white cane and assists the user to avoid collisions and falling down. Utilizing recent advancements in information technology, we have introduced a smartphone as an ETA. The proposed fall risk alert system detects fall risk areas in the walking direction of the user based on a depth image obtained by a smartphone. The system calculates the fall risk based on the shortest distance to the edge of a platform and generates an alert as vibration from the smartphone or smartwatch. We conduct verification experiments using the smartphone-based fall risk alert system on a train platform in collaboration with visually impaired persons, who walk according to scenarios expected in daily life. The experimental results demonstrate that the system generates fall risk alerts on station platforms. Based on the walking paths and questionnaire answers, the proposed system is considered to provide similar information with tactile paving.