BRAIN COMPUTER BRAIN COMPUTER INTERFACEINTERFACE

Presented by:

V.Lakshana

Regd. No.: 0601106040

Information Technology

CET, Bhubaneswar

Brain Computer InterfaceBrain Computer Interface

from fiction from fiction from fiction from fiction

to reality ...to reality ...to reality ...to reality ...

In the futuristic vision of the Wachowski brothers’ movie

trilogy “The Matrix”, humans dive into a virtual world by

connecting their brains directly to a computer……..

MOVIE FICTION: THE MATRIX

OVERVIEWOVERVIEWDefinition

General Principle

Background

Component

Simplified model of BCI

Training of BCI system

Current BCI approaches

EEG Based BCIEEG Based BCI

BCI for Tetraplegics

Brain controlled robots

Present Development and Future

Applications

BCI for Healthy Users

Advantages

Computational Challenges

Future Expansion

Conclusion

DEFINITIONDEFINITION

A Brain ComputerInterface (BCI) is acollaboration in which a brain accepts and a brain accepts and controls a mechanical device as a natural part of its representation of the body.

GENERAL PRINCIPLEGENERAL PRINCIPLE

(a) (b) (c)

(a) In healthy subjects, primary motor area sends movement commands to muscles via spinal cord.

(b) In paralyzed people this pathway is interrupted.(c) Computer based decoder translates this activity into

commands for muscle control.

BACKGROUNDBACKGROUND

Signals from an array of neurons read.

Cerebral electric activity recorded.

Signals are amplified.

Transmitted to computer

Transformed to device

control commands.

Using computer chips and programs.

Signals translated into action.

BASIC COMPONENTSBASIC COMPONENTS

The implant device, or chronic multi-electrode array

The signal recording and processing section

An external device An external device the subject uses to produce & control motion

A feedback section to the subject

Implant DeviceImplant Device

Conduct electricity Biocompatible material(teflon)Placed on the scalpChemically inertProvide the electrical contact

between the skin and the EEGbetween the skin and the EEGrecording apparatus AN ARRAY OF MICROELECTRODES

BLOCK DIAGRAM OF THE NEUROTROPHIC ELECTRODES FOR IMPLANTATION IN HUMAN PATIENTS

Signal Processing SectionSignal Processing Section

Multichannel Acquisition Systems

Spike Detection

SIMPLIFIED MODEL OF THE BCI SYSTEMSIMPLIFIED MODEL OF THE BCI SYSTEM

TRAINING OF BCI SYSTEMTRAINING OF BCI SYSTEM

Two different approaches:

Pattern Recognition Approach

Operant Conditioning Approach

BLOCK DIAGRAM FOR LEARNING MODE

BLOCK DIAGRAM FOR LEARNING MODE

CURRENT BCI APPROACHESCURRENT BCI APPROACHES

BCI

APPROACHES

INVASIVESEMI-

INVASIVE

NON-

INVASIVE

EEG Based BCIEEG Based BCIElectroencephalography (EEG) is a method used in measuring the electrical activity of the brain.

The basic frequency of the EEG range is classified into five bands for

Band Frequency [Hz]

Delta 0.5- 4

Theta 4- 8

Alpha 8- 13

Beta 13- 22

Gamma 22-30

into five bands for purposes of EEG analysis called brain rhythms .

The alpha rhythm is one of the principal components of the EEG and is an indicator of the state of alertness of the brain.

Development of BCIDevelopment of BCIEarly workAlgorithms to reconstruct movements from motor cortex neurons, which control movement were developed in 1970s.

The first Intra-Cortical Brain-Computer Interface was built by implanting neurotrophiccone electrodes into monkeys.

After conducting initial studies in rats during the 1990s, researchers developed Brain Computer Interfaces that decoded brain activity in monkeys and used the devices to reproduce monkey movements in monkeys and used the devices to reproduce monkey movements in robotic arms.

Present Developments BCI for Tereaplegics

Brain controlled Robot

‘BRAINGATE’ BCI

ATR and HONDA’s new BCI

BCI2000

BCI for TetraplegicsBCI for Tetraplegics

6- channel EEG BCI used.

Sensory & motor cortices activated during attempts.

Control scheme sends movement intention to movement intention to Prosthetic Controller.

Prosthetic returns force sensory information to Controller.

Feedback processed and grip is adjusted.

BRAIN CONTROLLED ROBOTSBRAIN CONTROLLED ROBOTS

Robot hand mimics subject’s finger movements.

Signals extracted and decoded by computer program.

Transferred to hand shaped robot.

To simulate original movement performed.

Robot executes commands using onboard sensor readings.

‘BRAINGATE’ BCI‘BRAINGATE’ BCI

The ‘Braingate’ device can provide motor-impaired patients amode of communication through the translation of thought intodirect computer control.

FEATURES OF BRAINGATE BCIFEATURES OF BRAINGATE BCI

Neural Interface Device.

Consists of signal sensor and external processors.

Converts neural signals to output signals.

Sensor consists of tiny chip with Sensor consists of tiny chip with electrode sensors.

Chip implanted on brain surface.

Cable connects sensor to external signal processor.

Create communication o/p using decoding software.

ATR & HONDA DEVELOP NEW BCIATR & HONDA DEVELOP NEW BCI

BCI for manipulating robots using brain signals.

Enables decoding natural brain activity.

MRI based neural decoding.MRI based neural decoding.

No invasive incision of head and Brain.

By tracking haemodynamicresponses in brain.

Accuracy of 85%

BCI2000BCI2000

BCI2000 is an open-source, general-purpose system for BCI research.

It can also be used for data acquisition, stimulus presentation, and brain monitoring applications.

During operation, BCI2000 stores data During operation, BCI2000 stores data in a common format (BCI2000 native or GDF).

BCI2000 also includes several tools for data import or conversion and export facilities into ASCII.

BCI2000 also facilitates interactions with other software.

BCI APPLICATIONSBCI APPLICATIONS

Medical applications(restoration of a

communication channel for patients with locked-

in syndrome and the control of neuroprostheses

in patients affected by spinal cord injuries )

Military applicationsMilitary applications

Counter terrorism(10 times faster image search)

multimedia and virtual reality applications

BCI FOR HEALTHY USERSBCI FOR HEALTHY USERS

Induced disability.

Ease of use in hardware.

Ease of use in software.

Otherwise unavailable information.information.

Improved training or performance.

Confidentiality.

Speed.

Novelty.

DRAWBACKSDRAWBACKS

EEGs measure tiny voltage potentials. The signal is weak and prone to interference.

Each neuron is constantly sending and receiving signals through a complex web receiving signals through a complex web of connections. There are chemical processes involved as well, which EEGs can't pick up on.

The equipment heavy(~10 lbs.) & hence not portable.

COMPUTATIONAL CHALLENGES COMPUTATIONAL CHALLENGES ANDAND

FUTURE IMPLEMENTATIONSFUTURE IMPLEMENTATIONS

Minimally invasive surgical methods.

Next generation Neuroprosthesis.

Vision prosthesis.Vision prosthesis.

BCI for totally paralyzed.

Minimal number of calibration trials.

Development of telemetry chip to collect

data without external cables.

CONCLUSIONCONCLUSION

A potential therapeutic tool.

BCI System is nominated for the

European ICT Grand Prize.European ICT Grand Prize.

Potentially high impact technology.

REFERENCESREFERENCES

www.howstuffworks.com

www.techalone.com

www.brainlab.org

Brain- computer –interface # Invasive-BCIs. Brain- computer –interface # Invasive-BCIs. Berlin Brain- Computer Interface

Brain Computer Interface, www.wikipedia.org http://en.wikipedia.org/wiki/

www.betterhumans.com

Thank youThank you