Seeing Aid for the Visual Impaired

A group of students from University of Washington’s Human Interface Technology Laboratory have been working on a wearable low-vision device. Meant to aid the sight-impaired, the device is a first of its kind and has its advantages over the canine friend.

Developed under the keen eye of Eric Seibel, a research assistant professor in mechanical engineering, the digital device was funded by the National science foundation.

According to Seibel, the low-vision device was designed to be both portable and economical. The device consists of a laptop computer carried in a backpack. A pair of glasses hosts the imaging system and combines a ring of light emitting diodes and a small camera. The diodes discharge spurts of infrared light while the camera collects the subsequent infrared illuminated scene.

Since closer objects reflect more light than distant ones, the system focuses on all items that stay within the field of view. The system then assesses the situation and transmits a warning signal to the wearer when they may be in danger. The different hazards that a person could face are allotted different icons to give the wearer a better idea of the surroundings.

The device can be customized to the needs of the individual. Seibel holds this aspect of the device as “one of the beauties” of it. Seibel points out that the obstacles for a person moving around in a small town are different from the obstacles that a person is bound to encounter in a city. This calls for tailoring the device to suit the change.

The device’s display is constructed of vibrating crystal fiber attached to a laser diode. Vibrating at high speeds of over a thousand times a second, the fiber forms a translucent “screen.” This image is beamed into the user’s eye and painted onto the retina. The brightness is variable and can be observed both indoors and outside.

The image also gets around the visual problems of many of its users. The bright laser light goes right through the optical problem of the eye and paints a larger image on the retina, at times even for people with retinal problems. Using visual prompts, the device leaves intact the other key sense dear to people with low vision - hearing.

Ryland Bryant, a master’s graduate and author of the Seattle conference paper, built a new circuit board that drops the general weight of the system by a half-pound at least. The team is likely to use an improved micro–optical scanner with higher resolution but one-tenth the original size.

Seibel and his team are preparing themselves to experiment with laser light on the neurons in the eye, enabling sight even if the eye’s photoreceptors are dead. Though in its nascent stage, Seibel and his collaborators have tentatively worked out some possible ways to develop the futuristic device .

Source: UWNews