Created by [Nilay Roy Choudhury], the device is intended to be worn on the waist, and features two sets of ultrasonic sensors. One set is aimed straight ahead, while the other points upwards at an angle of 45 degrees. An infrared sensor then points downward at an angle of 45 degrees, aimed at the ground.
The distance readings from these sensors are then collated by a microcontroller, which uses trigonometry to determine the user’s actual distance to the object. When objects are closer than a given threshold, the device provides feedback to the user via a buzzer and a vibration motor. The combination of three sensors looking out at different angles helps capture a variety of obstacles, whether they be at head, chest, or knee height.
It’s unlikely that a complex electronic device would serve as a direct replacement for solutions like the tried-and-tested cane. However, that’s not to say there isn’t value in such tools, particularly when properly tested and designed to suit user’s needs.
The white cane (and its many variants) is an everyday carry for many visually impaired people. This low-tech tool allows those afflicted by visual impairment to safely navigate the world around them, and has been ubiquitous in many parts of the world for decades. [Madaeon] has been hard at work going one step further in prototyping an open-source assistive wearable that could help in situations where a cane is not practical, or useful.
The T.O.F Wristband V2 alerts its wearer to nearby obstacles through vibrations, and is able to detect objects up to four meters away. As the wearer veers closer and closer to an obstacle, the vibration increases in frequency. A time-of-flight distance sensor is controlled by a Feather, and the whole system is powered by a small lithium-polymer battery. The prototype consists of just four components plus a 3D printed case and bracelet, which inevitably keeps down costs and complexity.
Version two of this project picks up where version one left off. In that project, [Madaeon] mentioned the possibility of squeezing this project down to the size of a ring. Perhaps with better battery technology, a ring-sized sensor might just be possible one day.
This isn’t the first wearable that has set out to assist the visually impaired. Back in 2019 we covered a laser-augmented glove that attempts something very similar.
By some estimates, nearly one billion people worldwide have some degree of visual impairment. Assistive devices like the T.O.F Wristband V2, and others like it, offer these people the potential for greater independence and an improved standard of living.
Visual impairment has been a major issue for humankind for its entire history, but has become more pressing with society’s evolution into a world which revolves around visual acuity. Whether it’s about navigating a busy city or interacting with the countless screens that fill modern life, coping with reduced or no vision is a challenge. For countless individuals, the use of braille and accessibility technology such as screen readers is essential to interact with the world around them.
For refractive visual impairment we currently have a range of solutions, from glasses and contact lenses to more permanent options like LASIK and similar which seek to fix the refractive problem by burning away part of the cornea. When the eye’s lens itself has been damaged (e.g. with cataracts), it can be replaced with an artificial lens.
But what if the retina or optic nerve has been damaged in some way? For individuals with such (nerve) damage there has for decades been the tempting and seemingly futuristic concept to restore vision, whether through biological or technological means. Quite recently, there have been a number of studies which explore both approaches, with promising results.