Abstract
There are approximately 300, 000 visually impaired persons in Japan. Most of them are old and cannot make appropriate use of their white cane. Therefore, it is imperative to develop some instruments that support the independent activities of the visually impaired.
In this paper, we will discuss an instrument developed by us, which enables the visually impaired to walk independently in an indoor space. This instrument consists of a map information system and a navigation system. Optical beacons and a receiver for these beacons are used in the map information system. The optical beacons are set on the ceiling and emit the position code as an infrared signal. The receiver receives this signal from the beacons and notifies map information to the user by a pre-recorded voice. This navigation system can follow a colored guideline that is set on the floor. In this system, a color sensor installed on a white cane senses the colored guideline, and by vibration, the system informs the visually impaired that he/she is walking along the guideline.
Three normal subjects and two low-vision subjects who were blindfolded with an eye mask were tested with this system. All of them were able to walk along the guideline. The performance of the map information system was good. Therefore, we have concluded that our system will be extremely valuable in supporting the activities of the visually impaired.
