Wireless control of powered wheelchairs with tongue motion using tongue drive

assistive technology(TDS)

PROJECT ASSOCIATES

•Shijo John (1MV10EC099)•Santhoop K S (1MV10EC090)•Sudharshan R (1MV10EC108)•Vijay Narayan Reddy P S(1MV10EC117)

Bhuvaneswari N (Assistant Professor, Dept. of Electronics and Communication)

Under the guidance of

What is TDS?

TONGUE–OPERATED assistive technology for people with severe disability to control their environment

PURPOSE OF THE PROJECT

Traumatic spinal cord injury

Paralysis

EXISTING ASSISTIVE TECHNOLOGIES…

Sip-and-Puff wheel chairJoystick Controlled

Voice activated powered wheelchair Head control

Why Tongue?...

• MUSCLE fibers in tongue is similar to heart muscle fibers

• LOW rate of Perceived Exertion

• DIRECTLY connected to the brain

• HIDDEN inside mouth will give a certain degree of privacy

FRONT BACK

LEFT RIGHT

MAGNET POSITION

BASIC PRINCIPLE

TRANSMITTER BLOCK DIAGRAM

HALL SENSOR

HALL SENSOR

HALL SENSOR

HALL SENSOR

MICROCONTROLLER

(AT89S52)

RF Transmitter

Front

Back

Left

Right

TRANSMITTER CIRCUIT

RECEIVER BLOCK DIAGRAM

MICROCONTROLLER

(P89V51RD2)

RF Receiver

Motor2

Motor1

Motor Driver

PROXIMITY

SENSOR

RECEIVER CIRCUIT

INDUSTRIAL MODEL

HARDWARE

SENSOR- Hall effect sensor

• TRANSDUCER which varies its output voltage in response to changes in magnetic field

• Input Voltage: 4.5V - 24V• Output is a digital voltage 0 and 0.3 V

• 8K Bytes of In-System Reprogrammable Flash Memory.• 256 x 8-bit Internal RAM• 32 Programmable I/O Lines• Three 16-bit Timer/Counters• Eight Interrupt Sources

Microcontroller(AT89S52)

RF Transceiver

• Its frequency is 433MHZ

• It can transmit upto 100 meters distance

• HT12E is the Encoder

• HT12D is the Decoder

H-BRIDGE DRIVER

• L293

• Bidirectional-H Bridge driver

• 5V power supply is given

DC MOTORS

• 12V DC motors

• USED 2 motors: Left and right

• LEFT motor at rest and right in motion turn vehicle left and vice versa

• FOR forward and backward motion both the motors are driven in same direction with same speed

SOFTWARES

• Keil µVision 3• Language : Embedded C• Flash Magic

APPLICATION AND FUTURE SCOPE•It empowers people with disability to achieve maximum independence at home and in the community by enabling them to drive a power wheelchair and control their environment in a smoother and more intuitive way.

•Future scope of the project includes the ability to control various household devices like TV, air-condition etc. Also the user can control computers and mobile phones.

DISADVANTAGES

• USERS should avoid inserting ferromagnetic objects in their mouth.

• MAGNETIC tracer should be removed if the user is undergoing MRI.

CHALLENGES

We have faces a number of challenges in this project and also learned a number of new terms and microcontroller terminology.

• Hall sensor output voltage was not enough to activate a microcontroller pin.

• Back E.M.F produced by motors.• Exact Positioning of sensors.• Turning the vehicle Left or Right.

DEVELOPMENTS

QU

ES

TIO

N T

IME

REFERENCES•Yousefi, Xueliang Huo, Ghovanloo M "Preliminary assessment of Tongue Drive System in medium term usage for computer access and wheelchair control", Engineering in Medicine and Biology Society, EMBC, 2011 Annual International Conference of the IEEE, Pages 5766 - 5769, Aug.30 2011 - Sept.3 2011

•http://www.news.gatech.edu/features/tongue-drive-wheelchair

•Assistive technology devices, Available: http://www.wheelchairnet.org/WCNProdServ/Products/OtherATprod.htmI