Before deciding on the specificities of our project, we did some market research to gather information on the needs of the visually impaired. The research on the existing products in the market also helped out glean insight into what the visually impaired are currently using and what is lacking.
More specific to what we were interested in is Sensor-based Assistive Device For The Visually Impaired.
Visual Assistive Technology is generally divided into three categories: visual enhancement, vision substitution and vision replacement [2]. Each category is elaborated on below:
The estimated number of people visually impaired in the world is 285 million, 39 million blind and 246 million having low vision [1]. Because of the large number of visually impaired people around us, there have been many ventures to improve the current state of technology to help increase the mobility of the visually impaired. Here’s what we have gathered:
There are also devices that make use of electrodes placed on the roof of the mouth, sending pulses to the tongue. Some others are worn on the chest level, hands, waist area, or on the head. Some technologies are rather bulky, requiring not only sensors and cameras but also for the visually impaired to carry laptops with them. Because 65% of people visually impaired and 82% of all blind are 50 years and older [1], these bulky technologies may actually hinder their movement as the agility of the visually impaired in that age group is decreased. Thus, we hope that our device will be light and not be a hindrance to the visually impaired’s day-to-day activities.
Apart from bulkiness, there are features that help gauge the efficiency and reliability of the electronic devices provided for the blind. The end product devised should try to incorporate all the features below [2]. This table would guide our ideation as we try to tune and find a fine balance between each feature.
Vibrations and auditory responses are most commonly used with visual aid devices. Some considerations that we had were that the visually impaired could not differentiate all vibrational patterns. It is crucial that the display (either vibrational or auditory) is clear to ensure the safety of the user.
Another consideration arose from the need for the device to be worn for long periods of time, as well as when the user is outdoors. It needs to be functionally able in both night and day. The device needs to be energy saving and efficient for the convenience of the user, to reduce the need for portable batteries or charging frequently. Also, if it is to be worn for long periods of time, the comfort and convenience of wear are paramount.
Other devices
Royal National Institute of Blind People (RNIB) Assisted Vision Smart Glasses
RNIB’s smart glasses have:
- a transparent display – lenses appear clear to others and allow eyes to be seen.
- two cameras at the front of the glasses which mimic the location of your eyes to determine distance (stereoscopic vision).
- the ability to be adjusted to suit different eye conditions.
- night vision – smart glasses work both during day and night!
They are constructed using transparent OLED displays, two small cameras, a gyroscope, a compass, a GPS unit, and a headphone.
The cameras could also work with the computing module and the right software to recognize the number on an approaching bus,or to read a sign. The GPS module can be used to give directions. The gyroscope helps the glasses to calculate changes in perspective as the wearer moves. All of the information is spoken aloud through the built-in earpiece [3].
ARIANNA
Arianna is a phone application that maps out a route through a building by sticking coloured tape on the ground. A smartphone camera is pointed towards the ground and a finger is placed on the screen. The user then waves the camera back and forth to scan the ground for the line. In so doing, the app analyses the frames produced by the camera, picking out the line as it moves across the screen. When the line passes under the user’s finger on the screen, the app causes the smartphone to vibrate, providing a tactile indication of where the line falls. Scanning the smartphone back and forth allows the user to follow the line in the same way as he or she might use a cane (see diagram above). At the same time, QR codes placed on the ground can give the user other information such as the location of places such as toilets, water coolers, shops and so on [4].
The app provides positioning service indoors where it is difficult for GPS to work. It can also be widely used because the cost of an app will be significantly cheaper than a bespoke device.
Smart canes
Smart canes are assistive devices for the blind. They extend the capabilities of existing white canes being able to detect both above and below knee level obstacle and provides audio feedback, provides voice navigation, emergency alert to loved ones, and transportation services. The BAWA cane is an example of a smart cane.
The BAWA cane is extremely light, weighing less than 350 grams, and promises a battery life of more than 10 hours. It is greatly ergonomic and scrupulously engineered to detect and alert users of above knee level obstacles up to 1.2 meters above the waist, detect and alert users of objects as small as 25.4 millimetres on the ground, and detect and alert users of steps or sudden drops as small as 25.4 millimetres [5].
Citations:
[1] World Health Organisation
[2] Sensor-Based Assistive Devices for Visually-Impaired People: Current Status, Challenges, and Future Directions/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5375851/
[3] RNIB/ https://www.rnib.org.uk/smart-glasses
[4] Technology Review/ https://www.technologyreview.com/s/523401/app-turns-smartphone-into-virtual-cane-for-the-blind/
[5] BAWA cane/ https://www.bawa.tech/product/