Kc techsem tds

TONGUE DRIVE SYSTEM

BY

N.CH.KRISHNA CHAITANYA (10P71A0437)

INTRODUCTION :- It is a tongue

operated assistive technology developed for people with severe disability to control their environment

Tongue is considered to be an excellent appendage in severely disabled people for operating an assistive device

What is this all about??

The novel system that allows individuals with disabilities to operate a computer, control a powered wheel chair and interact with their environment simply by moving their tongues

This device could revolutionize the field of assistive technologies by helping individuals with severe disabilities such as those with high-level spinal cord injuries return to rich, active, independent and productive lives

Why Tongue??

Unlike hands and feet ,which are controlled by the brain through the spinal cord, the tongue is directly connected to the brain by a cranial nerve that generally escapes damage in severe spinal cord injuries or neuromuscular diseases

Tongue movements are also fast, accurate and does not require much thinking, concentration or effort

PARTS OF TONGUE DRIVE SYSTEM:-

Permanent magnet

Magnetic

sensors

Control unit

External receiver

IMPLANTATION :-

Permanent magnet placed on the tongue

Magnetic sensors wore as a head set or as a orthodontic trace inside the mouth

Wireless t transceiver connected to the headset and wore to head

How does it work?

To operate the Tongue Drive System, potential users only need to be able to move their tongues.

Attaching a small magnet, the size of a grain of rice, to an individual’s tongue by implantation, piercing or tissue adhesive allows tongue motion to direct the movement of a cursor across a computer screen or a powered wheel chair around a room

How does it work??

Movement of the magnetic tracer attached to the tongue is detected by an array of magnetic field sensors mounted on a headset outside the mouth or an orthodontic brace inside the mouth. The sensor output signals are wirelessly transmitted to a portable computer(PDA), which can be carried on user’s clothing or wheel chair

An SSP Algorithm running on the portable computer classifies the sensor signals and converts them into user control commands that are wirelessly communicated to target devices in user’s environment

Operation of Tongue computing ( TDS) :-

Internal working :-

Control unit :The sensor output signals are

processed to determine the relative motion of magnet with respect to the array of sensors in real-time .This information is then used to control the movements of a cursor on the computer screen or to substitute for the joystick function in a powered wheel chair. This SSP algorithm running on PC is developed by LABVIEW or MATLAB

The system can potentially capture a large number of tongue movements, each of which can represent a different user command. A unique set of specific tongue movements can be tailored for each individual based on user’s abilities, oral anatomy, personal preferences and lifestyle

Training and TestingEach participant defined 6 tongue commands that

would substitute for computer mouse tasks –left,right,up and down pointer movements

For each trail, the individual began by training the system. During a 5 minute training session, the individual repeated each of six designated tongue movements 10 times

During testing session, the user moved his/her tongue to one of the predefined command positions and the mouse pointer started moving in the selected direction. To move cursor faster, users could hold their tongue in the position of issued command to gradually accelerate the pointer until it reached a maximum velocity

Advantages Due to continuously position dependent property of

linear functions of magnetic field only few sensors are able to capture a wide variety of tongue variations

Advantageous over switch based devicesSmoother, faster and more natural controls as user is

saved the trouble of multiple on-ff switch operations Noise effective and Robust against interference due

to proximity of the magnet and Hall-effectASIC along with transmitted antenna can be

incorporated into a miniaturized package that may be fitted under the tongue as a part of dental retainer

Disadvantages

Implementation is slightly harder Slightly costlier

Too much load on tongue and oral cavity

Applications A disabled person can

drive a wheel chair.

Can operate a computer in which the person can type words, play games.

Manipulation of a mobile device through an assistive tongue computing.

Future of TDS To control a robotic

arm to use it to eat, drink, hold any thing and use it as a natural arm.

To use in everyday purpose and to control the activities going on around without any difficulties.

Conclusion

The operating principle and set up of such a novel passive tongue HCI has been established with successful laboratory trials & experiments

Further clinical trials will be required to test out the devices on disabled persons before it is ready for future commercial development

Result The device is able to perform two main pc functions that

of the keyboard and mouse. Results of test conducted by novice users showed response time of less than one second with 100% accuracy for 6 individual commands which is approximately equal to

bit rate of 150 bits/minute

The results show that this device allows the severely disabled person to have some control in his environment such as to turn on/off or control daily electrical appliances.

Researches are planning to add control commands such as switching the system into standby mode to

permit user to eat, sleep or engage in a conversation

References :-An IEEE Paper on “Tongue Drive: A Tongue operated

Magnetic Sensor Based wireless Assistive technology for people with Severe Disabilities”

From the website of School of Electrical and Computer Engineering, Georgia Institute of Technology

http://users.ece.gatech.edu/mghovan/index_files/TongueDrive.htm

From the website of GT Bionics Laboratory, Department of ECE, Georgia Institute of Technology.

http://www.ece.gatech.edu/research/labs/gt-bionics/research_tds.shtml

Krishna Chaitanya Nallan Chakravartula www.kc-nallanchakravartula.blogspot.in 10P71A0437