Assistive techonologies and devices for visually impaired

1. BY
UMAR SHUAIBU
(ROLL NO. 140125014)
ASSISTIVE TECHNOLOGIES AND
DEVICES FOR VISUALLY IMPAIRED

2. 1.0 INTRODUCTION
 The human eye is like camera that receives and
focus light into retina which is then transmitted to
the brain.
 Without retina, eye cannot see thus, render vision
impossible, hence the visual impairment.

3. 1.1 VISUAL IMPAIREMENT
 The decrease in the ability to see to the extent
that causes problem which cannot be restore to
the normal vision is known as visual impairment.
According to international organisation for
disease classification, there are for level of visual
function which are:

4.  Normal vision
 Moderate visual impairment
 Severe visual impairment and
 Blindness.
The visually impaired persons face real challenges in
moving through dynamically changing environment,
in learning, and many other activities for his daily
living, thus tend to undermine his independence, as
such different assistive technologies and devices
were developed

5. ASSISTIVE TECHNOLOGIES AND
DEVICES
 Assistive Technology is a generic term incorporating
technology, equipment, devices, appliances, services,
systems, processes and environmental change
(Environmental Modifications) used by people with
disabilities or older people to overcome social, and
infrastructural barriers, to actively participate in society
and to perform day-to-day activities easily, safely, and
efficiently.
 The visually impaired persons need security, safety,

6. And devices can be grouped into the following
 Assistive technologies and devices for daily living
 Assistive technologies and devices for navigation and
orientation
 Assistive technologies and devices for learning. etc

7. 2.0 ASSISTIVE TEHNOLOGIES AND
DEVICES
FOR DAILY LIVING
This can also be grouped into the following
 Personal care,
 Timekeeping, alarms and alerting,
 Food preparation and consumption,
 Environmental control/ household appliances,
 Money, finance and shopping

8. The personal care assistive technology refers to two main aspects:
labelling and health care monitoring systems.
LABELLING SYSTEM
Visually impaired people need assistance in identifying different
elements of their clothing. Labelling can be grouped in the
following types of systems
2.0.1 ASSISTIVE TEHNOLOGIES AND
DEVICES
FOR PERSONAL CARE

9. Tactile labelling system which is based on different
alphabets used for visually impaired like Braille,

10. Barcode labelling system which is using barcode
reader and scanner, where a beam of light is send to
the barcode to be read, and the reflected ray is then
read by the reader.

11. And the radio frequency identification labelling
system
Where by a tag is given to each items, and then the
tag is read by the reader using radio signal
whenever the tag is within the field of the reader

12. HEALTH CARE MONITORING SYSTEM to assist visually
impaired people in monitoring their general health, among
which are:
Talking blood pressure meter which measure the blood
pressure and give audio output of the result.

13. talking blood glucose meter that measure blood
glucose level and give the voice output of the result.

14. 2.0.2 TIME KEEPING, ALARM AND
ALARTING
One can meet different types of time devices that exist for
blind and visually impaired people. Many of these have
speech or tactile output,
Among which are:
Braille watch that give the time in Braille text

15. Talking watch with tactile output that provide both audio
as well as the Braille output.

16. And talking carbon monoxide detector which when
detect the carbon monoxide inform this through voice
output

17. 2.0.3 FOOD PREPARATION AND
CONSUMPTION
The food preparation and consumption play a significant role
in the independent living of a visually impaired. There are
different assistive technologies and devices in food
preparation and consumption among which are:
Talking kitchen thermometer which provide the audio
output of the cooking temperature for the visually impaired

18. Talking kitchen scale which provide the audio output of
the cooking ingredient and the foodstuff for visually
impaired. And many more

19. 2.0.4 ENVIRONMENTAL
CONTROL
The control of the immediate home environment of the
visually impaired people is a condition for their
independent life. This means that they have to control a
number of home devices and that they have a constant
need for feedback from their environment, so that they
can accommodate to changes. Light probe and colour
probe devices can be used to get information from the
environment. talking and tactile thermometers and
barometers, washing machine with special functions for

20. 2.0.5 MONEY, FINANCE AND
SHOPPING
Money is another important aspect of independent life.
Accessing it by visually impaired people can be difficult,
because of different currency systems. Thus the
development of tools that can recognize more, or at
least the most commonly used, currencies is an
important aspect of assisting visually impaired people in
gaining independence.

21. DEVICES
FOR NAVIGATION AND
ORIENTATION
Navigation of visually impaired people raises questions
about orientation, the appropriate route selection,
objects and obstacles detection and avoidance.
Electronic systems used in navigation can be grouped
into two categories:
 Electronic travelling aids(ETAs)
 Electronic orientation aids(EOAs)

22. 3.0.1 ELECTRONIC TRAVELLING
AID(ETAs)
In recent years the traditional tools used by visually impaired
people for ETA systems are complex tools to support
navigation and are composed of several basic modules
among which are:
obstacle detection system
trajectory planning module,
Monitoring system.

23. Electronic travelling aids is a form of assistive technology
having the purpose of enhancing mobility of visually
impaired. Perhaps the most widely known electronic
travelling aids for improving or enhancing the mobility
of a visually impaired can be discuss as follow

24. ULTRACANE
Ultra cane mimics the innate echolocation capability of bat and
dolphin. Bat and dolphin make high frequency sound that
bounce off whatever is in front of them. They received these
sound and can sense the size, shape, density, distance and
even texture of an object

25. The ultra cane emit ultrasound in two mode, the short range
for detecting an object within two meters, and the long
range for detecting object within four metres of the
handle

26. There are two in the handle of the cane which vibrate at
various intensity to indicate an object proximity and
position. Object on the ground in front of the visually
impaired is detected by the lower tactile button. while the
top tactile button is vibrate when the visually impaired
approached an object between hip and the head level

27. BIONIC EYE
The bionic eye ( also known as argus11) system
consisted of pair of glasses with small video
camera mounted on it, which capture image. A
small prosthesis is surgically implanted on the
surface of the retina, and the information from the
camera is transmitted wirelessly to electrode on the
artificial retina. Where it is converted into electrical
pulses, any remaining cells that haven’t been

29. 3.0.2 ELECTRONIC ORIENTATION
AIDS(EOTs)
Electronic orientation aids have been designed to give
orientation and way finding information to blind and
partially sighted people. The information they can
provide includes location and direction information as
well as information on objects in the user’s
environment. An example of an electronic orientation
aid is the RNIB REACT system, this system is in use
in a number of places including

30. Leeds bus and train stations. The RNIB REACT sign speaks
a message as the blind or partially sighted user walks up to
it. The blind and partially sighted person can then follow
the spoken instructions to find the help point or their stop.
The available GPS devices for blind people are the Way
finder system, like the The geotact which basically is a
GPS sensor. In this system the direction and distance to
the next point are given in form of voice, the visually
impaired is then required to utilizes the locomotion skills

32. 4.0 ASSISTIVE TECHNOLOGIES AND
DEVICE
FOR LEARNING
Students with visual impairments face unique challenges in the
educational environment. Not only must they be able to access
text information across all curricular areas, but they also need
to be able to participate fully in instruction that is often rich
with visual content. Assistive technology is one way of
supporting them in that process. Hence assistive technologies
in learning can be categorizes into two
 Assistive technologies and devices for reading and
 Assistive technologies and devices for writing

33. Assistive technology tools to support reading should reflect the
student’s level of visual functioning, their literacy development,
as well as the environmental and task demands. Some of which
are:
Braille: which is a system of touch reading and writing for blind
persons in which raised dots represent the letters of the alphabet.
DEVICE
FOR READING

35. Audio book which recorded using human voice, and
can be accessed through the use of specialized
computer software, devices, or mainstream tools like
MP3 players. etc

36. reading pen which provided the audio output of the
scanned text. etc

37. The assistive technologies for writing for the visually
impaired are also significant for their independent
living among which are:
Braille note taker which is a portable word
processing device that utilizes the eight key Braille
input system and has an integrated refreshable
Braille display.
4.0.2 ASSISTIVE TECHNOLOGIES AND
DEVICE
FOR WRITING

38. Close circuit television (cctv) which allow magnification
of the writing for the visually impaired, and many others

39. 5.0 CONCLUSION
The assistive technologies used by visually impaired people
are very complex. A wide range of different electronic
assistive technologies exist and are used by visually
impaired. Some of these tools are unreachable by most of
the visually impaired persons. The integration of different
assistive solutions in a single assistive system is a great
challenge.