Brain computer interface.

It is a direct communication path way

between a human brain or animal brain

and external device.

BRAIN WAVES

There are four categories

Beta waves

Alpha waves

Theta waves

Delta waves

BETA WAVES:-

• Low amplitude

•Faster of all waves

•15-40c/s

ALPHA WAVES:-

•High amplitude

•Non-arousal

•9-14c/s

THETA WAVES:-

•Greater amplitude

•Day dream

•5-8c/s

DELTA WAVES:-

•Greater amplitude

•1.5-4c/s

•Never become zero

• It contains electrodes which are placed on the skull in an arrangement called 10-20 system.

• Main function of the electrode cap is to take the brain signals in the form of electrical signals

Output signal from the electrode cap will

be in the range of milli volt & microvolt

Hence there is a need for amplification

Pair of electrodes-one amplifier

Output signals are analog in nature

So the signals are sent to ADC to convert

the analog signals to the digital signals

Using the ouput signal from the a/d conv.

Parameter extraction, pattern classification & pattern identification are done.

Then the signal is fed to FFT unit for simplifying the calculations

It performs the robotic operations with

the help of stepper motor

It will control the operations like walking,

running etc.

•Waves are pre recorded for operation

•Signals are stored in micro controller

•If brain wave matches with the pre recorded signals then

operation is performed

•Idea can be extended for both the legs

•System is versatile

•Feasible in real time environment

• It uses Li-ion battery

• It require to charge once in 2days

• The life time will be longer when compared to other batteries

Brain Controlled Artificial Legs Normal Artificial Legs

1. Ease of Construction 1. Complex in construction

2.Cost is not more than Rs.5,00,000 2. Cost is about $80,000-

$90,000(Rs.35,00,000 to Rs.40,00,000)

3.User can have full control over the

artificial leg.

3. User cannot have full control over the

artificial leg.

4.Semi-Automatic 4. Fully Automatic

5.Sensors are absent. 5.Sensors are present

6.Requires simple control unit. 6. Requires complex control unit.

• The performance of the proposed system will be better than the existing artificial legs

• With the system life can be made easier for the differently abled persons