main seminar pp1t ambika

8/7/2019 main seminar pp1t ambika

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Brain Computer Interface

by- AMBIKA K VBE 8th Sem.

VCET,PUTTUR


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Overview

Introduction

What is BCI

History

Neuroimaging in BCIs

Architecture

Output device

Advantages and Disadvantages

Applications

Current projects Conclusion

References


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Introduction

It is the study of brain functions

BCI are system that provide translation of theelectrical activity of the human brain intocommand which can control device in realtime.

An Electroencephalogram based Brain-

Computer-Interface (BCI) provides a newcommunication channel between the humanbrain and a computer.


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What is BCI

Brain-Computer Interfaces (BCI)

Interaction between the human neural system and

machines

It often aimed at assisting, augmenting or repairing

human cognitive or sensory-motor functions.

Goal

Enabling people (especially disabled) to

communicate and control devices by mere

thinking.

BCI is a control system


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History- Discovering the Basics

1924: Hans Berger discovers the EEG

Analyses the interrelation of EEG and braindiseases.

1970: First developments to use brain waves asinput

ARPA has vision of enhanced human

First step in the right direction


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History-Monkey first

1990: First successful experiments with

monkeys

Implanting electrode arrays into monkeybrains

Recording of monkeys brain waves

2000: Monkeys control robots by thoughts


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History - Humans follow

More non-invasive than invasive approaches

Brain reading by eg. EEG, MEG or fMRI

2004: First human benefits from research Matt Nagle is able to control a computer and

move a prosthetic hand


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Reading the brain

Direct Neural

Contact

- Most accurate method

- Highly invasive

- Not possible with current

technologies

- Perhaps possible in future with e.g.

nanobots

Electroencephalogy

(EEG)

- Measures electical activity in brain

- Non-invasive

- Susceptible to noise

- Easy to use + low cost + portable

- Most commonly used device in BCIs

- It proposes 10-20 electrode

placement system


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Reading the brain

Magnetoencephalogy

(MEG)

- Measures magnetic fields produced

by electrical activity in brain

- Non-invasive

- Very accurate

- High equiment requirements and

maintenance costs

Functional Magnetic

Resonance Imaging

(fMRI)

- Measures blood flow in brain using

MRI (haemodynamics)

- Blood flow correlates to neural

activity

- Studies the brains function

- Very accurate

- Very high costs due to MRI


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Architecture


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Elements of a BCI

1) Signal Acquisition: the EEG signals are obtained from the brain

through invasive or non-invasive methods (for example,electrodes). After, the signal is amplified and sampled.

2) Signal processing: the signals are cleaned, they will beprocessed andclassified to find out which kind of mental task thesubject is performing.

1) Signal Pre-Processing: once the signals are acquired, it isnecessary to clean them.

2)feature extraction: emotions is one form of feature. Theyare 4 approaches.

3)pattern recognition: They are two basic reaction patterns

-Approach(love and joy): positive emotions.

-Avoidance(sorrow, fear): negative emotions.

3) Computer Interaction(output): once the signals are classified,&converted into commands, they will be usedby an appropriatedevice for the development of a certain application.


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Ouput Device

Wheel ChairAnswering yes/no questions


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Output device

Virtual Reality

U. S. Navy personnel using a virtual

reality parachute trainer


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BCI Pros/cons

Advantages:

- Increased the possibilities in treating disabilities related to

Nervous system.

- Used for Physically disabled.

- Techniques like EEG and MEG came in to existence by the

development of BCI concept

Disadvantages:

- Invasive BCI results in Scar tissues.

- Extensive training is required for user before using EEG and

other BCI components.

- BCI systems are complex and expensive


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BCI Applications

Medical applications : possibly only communicationchannel for people suffering from eg paraplegia,amyotrophia.

Human enchancement: any attempt to overcome thecurrent limitations of human cognitive and physicalabilities.

Human manipulation: a two way communication

between human and computer. Neuroprosthetics : surgically implanted devices used

as replacement for damaged neurons.


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Current Projects

Berlin Brain-Computer-Interface

Joint Venture of several German research

organisations

Supported by the Ministry of Education and

Research

Graz Brain-Computer-Interface

Wide range of research topics

Impressive combination of BCI and FES (Functional

Electrical Stimulation)


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Conclusions

Brain Computer Interface(BCI) is a method of communication

based on voluntary neural activity generated by the brain and

independent of its normal output pathways of peripheral

nervous and muscles.

The neural activity used in BCI can be recorded using invasive

or noninvasive techniques.

We can say as detection techniques and experimental designs

improve ,the BCI will improve as well and would provide

wealth alternatives for individuals to interact with their

environment.


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REFERENCES

[1] Wikipedia - internet encyclopedia

http://en.wikipedia.org/wiki/Brain-computer_interface

[2] http://www.seminarprojects.com/Thread-brain-

computer-interface-- 5412#ixzz1EbgIzsox

[3] IEEE Xplorer Digital Library website

http://ieeexplore.ieee.org/Xplore


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Any Questions..?


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Thank You

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