Posted by Vision Monday

One of the most enjoyable parts of my job as a tech journalist is reporting about designers who reimagine a familiar object and imbue it with new capabilities. I recently came across such a story involving four engineering students at Texas A&M University who set out to update the white cane. This simple but effective tool has been used since the 1920s by blind and visually impaired people to navigate surroundings and visually notify others of visual impairments.

The researchers developed a white cane attachment that can provide object detection and turn-by-turn navigation assistance via haptic feedback. Their project, the Navigational & Object Visual Assistant (NOVA), uses an ultrasonic sensor and vibration motors to alert white cane users of any obstacles above the waist with specific vibration patterns. The team also created a mobile application that will interact with the NOVA to signal directions to the user (e.g., turn left, or turn right).

NOVA’s ultrasonic sensor sends out a different voltage based on how far away the object is, then the voltage is read through an analog to digital converter and the vibration intensity fluctuates based upon the values read.

Hunter Schwedler, a software engineer who worked on the project and who consulted with visually impaired students on its development, offered insight on why vibration would be useful for users.

“[NOVA] has no auditory feedback at all, which is a big thing that the visually impaired students stressed that they wanted,” he explained. “They need to closely listen to their surroundings, and any sort of unnecessary sound can be distracting.”

By having the left and right motor for navigation and the center motor attached to the ultrasonic sensor, a user will be able to feel the difference between navigational and obstacle detection vibrations.

 

Although the idea of a high tech white cane might intrigue some potential users, it’s not for everyone. Elise Grossman, manager of vocational rehabilitation services for the Lighthouse Guild in New York City, said that few of the clients she works with are interested in new technology. “Most of them feel it’s too expensive, and are not comfortable with it. For example, MIT created this technology that involves wearing a sensor around your neck. It’s too cumbersome for our clients to wear.”

Grossman has not tested NOVA, but she is concerned that a device that emits vibrations may pose problems for visually impaired people in a real world situation. “Anytime you get close to wall, you could be overwhelmed by vibration,” she pointed out. “Users need to rely on all their senses to read environment. Some are afraid that with all the other sensations competing for their attention, they won’t be able to concentrate.”

However, others see potential benefits in NOVA and other assistive devices that use haptic or audio feedback to provide obstacle detection and avoidance information. “Identifying overhead obstacles without using a dog guide can be difficult, so this device could be a benefit to a blind traveler,” said Aaron Preece, a technology and information specialist for AccessWorld, a publication produced by the American Foundation for the Blind (AFB).

Although Preece hasn’t tried NOVA yet, he noted its unique properties. “The use of haptic feedback to provide what I gather would be GPS turn-by-turn directions is something I have not seen elsewhere in the industry.”