Brain Computer Interface

by- MANEESH RANJAN MCA 4th Sem. SJCE,MYSORE

Overview

• Introduction• Application• History• What is BCI• Structure and signals• Architecture/Logical structure• Brain waves• Functionality• Future Work• Conclusion• References

Introduction

• It is the study of brain functions• BCI are system that provide translation of the

electrical activity of the human brain into command which can control device in real time.

• An Electroencephalogram based Brain-Computer-Interface (BCI) provides a new communication channel between the human brain and a computer.

Applications

• Bioengineering applications: assist devices for disabled people.

• Human subject monitoring: sleep disorders, neurological diseases, attention monitoring, and/or overall "mental state".

• Neuroscience research: real-time methods for correlating observable behavior with recorded neural signals.

• Man – Machine Interaction: Interface devices between human and computers, machines.

History- Discovering the Basics

• 1924: Hans Berger discovers the EEG Analyses the interrelation of EEG and brain

diseases.• 1970: First developments to use brain waves as

input• ARPA has vision of enhanced human First step in the right direction

History-Monkey first

• 1990: First successful experiments with monkeys

• Implanting electrode arrays into monkey brains

• Recording of monkeys‘ brain waves• 2000: Monkeys control robots by thoughts

History - … Humans follow

• More non-invasive than invasive approaches• Brain reading by eg. EEG, MEG or fMRI• 2004: First human benefits from research

KEY ISSUES IN BCI RESEARCH AND USERS

RESEARCH DISCIPLINES

–Engineering–Clinical ...–Psychological–Neuroscience

KEY ISSUES IN BCI RESEARCH AND USERS

• Target users:Researchers - clinical researchers, neuroscientists,

signal processing experts, etc.Technical operators - caregivers, therapists who

are in charge of training someone on BCI operation.

End-users -people with disabilities who rely on the system for communication

Casual end-users -those who use a BCI as an alternative input for entertainment devices.

What is BCI

• Brain-Computer Interfaces (BCI) – Interaction between the human neural system and

machines– Goal• Enabling people (especially disabled) to communicate

and control devices by mere thinking.

– BCI is a control system

Structure of a BCI

Structure 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 Pre-Processing: once the signals are acquired, it is necessary to clean them.

• 3) Signal Classification: once the signals are cleaned, they will be processed and classified to find out which kind of mental task the subject is performing.

• 4) Computer Interaction: once the signals are classified, they will be used by an appropriate algorithm for the development of a certain application.

Signal Processing

• Feature Extraction• The Translation Algorithm

Output Device

• Any controllable machines– For answering yes/no questions– For word processing – Wheelchair– Virtual Reality

• Usually, Computer screen and the output is the selection of targets or cursor movement

Existing Solution Successful Story, Wearable BCI

◦ A successful transition of the whole BCI system to the portable device◦ No machine learning◦ Limited computational power (limited signal processing)

BCI2000◦ A general-purpose system for (BCI) research

Source Module (new device new driver) Signal Processing Module (reusable, No Machine Learning) User Application Module (UDP/IP support to be running in any machine)

◦ Platform Microsoft Windows™ 2000/XP C++ language

Wearable BCI

• Mobility– Communication technologies

• Bluetooth• 802.11(wire less –WLAN)• GSM/GPRS

– PDA instead of stationary computer• Dry Electrode instead of wet (reducing montage

time)• Making the BCI transparent– No need to change electrodes for a reasonable long time

Architecture

Logical scheme of BCI

PsychologicalEffort

(Intention)

Modification ofBrain Signals

Signal Features

ClassificationOf Intent

Increase of performance

appropriate feature extraction

user

train

ing com

pu

ter tra

inin

g

Environmentappropriate feedback strategy

CHARACTERISTICS OF BRAINWAVESTheta waves [4, 7.5] associated with reverie, daydreaming, meditation, creative ideas

Delta waves [0,4] Hz associated with deep sleep and in the awake state were thought to indicates physical defects in the brain.

CHARACTERISTICS OF BRAINWAVESAlpha wave(8-13hz)-its indicates both a relaxed and attention mode of the brain. Beta wave(13-30 hz)-it is the brain wave usually associated with activity thinking, active attention.

MU AND ALPHA WAVES

CHARACTERISTICS OF BRAIN WAVES

Gamma waves-within 35Hz-it reflect the mechanism of consciousness.

Mu wave(8-12)hz –associated with Motor activity,

Functionality of BCI

• Steps for the function of BCI.1.user wired to a multi-electrode EEG skin cap, which is

connected to a pc running BCI2000.2.user of the signal asked to generate a series of signals.3.EEG potential record and analyze the signal4.the software attempt to match these signal to

previous recorded signals.5.at last identified words are wrapped on output

devices like-screen or speech synthesizer.

Risk factors and alternate solution

Undergone through hurdle brain surgery.

New surgery for each up gradation

Risky and complicated eyes surgery.

Use wearable computing devices.

External device is good option.

Glasses and Lasik operation is best options.

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)

Future Work

• Virtual Reality • Bluesense,Sniff mode• Bluesense, Security

ConclusionsDistributed framework

◦ Controlling the Breakout video game through brain signalsBluesenseAD No ribbon cable

◦ Acceptable delay, sampling frequency ◦ Reliable◦ Robust

Game Server Application◦ TCP support◦ Simplicity

Video Game◦ Suitable for BCI experiment◦ Can be run on Java-enabled handsets

REFERENCES

• [1] IEEE Xplorer Digital Library website(Through SJCE Server) http://ieeexplore.ieee.org/Xplore • [2] Wikipedia - internet encyclopedia

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

Any Questions..…?

Thank You……