Scrib Brain Computer Interface

8/9/2019 Scrib Brain Computer Interface

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BRAIN COMPUTER

INTERFACE

Presented by:

Shri Charan K.M.

Roll no. 1DB06CS051.Department of Computer Science Engg.

DonBosco Institute of Technology.


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OVERVIEW

Definition

General Principle

Background

Components

Simplified Model of BCI

Current Brain ComputerInterface (BCI) Approaches

Invasive Approach

Semi-Invasive Approach

Non-Invasive Approach

BCI Applications

BCI Drawbacks

ConclusionReferences


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from fiction

to reality ..


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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


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DEFINITION

A brain-computerinterface,

sometimes called adirect neural

interface or a brainmachine interface, is

a direct

communicationpathway between a

human or animalbrain (and brain cell

culture) and an

external device.


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BrainBrain NeuronsNeurons BrainBrain isis filledfilled withwith

NeuronsNeurons..

SignalsSignals areare inin formform ofof smallsmall

NerveNerve cellscells areare connectedconnected

byby DendritesDendrites && AxonsAxons..

Electronic,Electronic, asas fastfast asas 250250mphmph..

SignalsSignals areare generatedgenerated byby

differencedifference inin ElectricElectric potentialpotential

carriedcarried byby IonsIons onon thethe

MembraneMembrane ofof eacheach NeuronNeuron..


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GENERAL PRINCIPLE

(a) (b) (c)

(a) In healthy subjects, primary motor area sends movementcommands 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.


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BACKGROUND

Signals from an array ofneurons read.

Cerebral electric activity

recorded.Signals are amplified.

Transmitted to computer

Transformed to device

control commands.Using computer chips andprograms.

Signals translated into action.


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CURRENT BCI APPROACHES

BCI

APPROACHES

INVASIVESEMI

INVASIVE

NONINVASIVE


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INVASIVE BCIOne of the first scientists to comeup with a working brain interface torestore sight as private researcher,William Dobelle IN 1978.

Are directly implanted into the greymatter of the brain duringneurosurgery.

Targeted in repairing damagedsight and providing newfunctionality to paralyzed people.

But these BCIs are prone tobuilding up of scar-tissue whichcauses the signal to becomeweaker and even lost as bodyreacts to a foreign object in the

brain.


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SEMI-INVASIVE BCI

Partially invasive BCI devices are implantedinside the skull but rest outside the brainrather than amidst the grey matter.

Electrocardiography (ECoG), electrodesare embedded in a thin plastic pad that isplaced above the cortex, beneath the Duramater.

Light Reactive Imaging BCI,The laserwould be trained on a single neuron and the

neurons reflectance measured by a separatesensor. When neuron fires, the laser lightpattern and wavelengths it reflects wouldchange slightly.


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M1 Handarea RoI

Scalp EEG

Virtual electrode

NON-INVASIVE BCI


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One of the biggest challenges BCI

facing is the Basic Mechanism of the

Interface itself

The Easiest & least invasive method is

a set of electrodes & the device whichis attached to the scalp is known as

ELECTROENCEPHALOGRAPH(EEG)ELECTROENCEPHALOGRAPH(EEG)..

The Electrodes can read the Brain

signals.

BCI EEG


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EEG COMPONENTS

Signal acquisition

Preprocessing

Feature extraction

Classification

Application Interface

Feedback

Brain signal

Control signal


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Electrode Placement

Standard 10-20 System

Spaced apart 10-20%

Letter for region

F - Frontal Lobe

T - Temporal Lobe

C - Center

O - Occipital Lobe

Number for exact position Odd numbers - left

Even numbers - right


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Electrode Placement

A more detailed view:


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J.R. Wolpaw et al. 2002

SIMPLIFIED MODEL OF THE BCI SYSTEM


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BCI Applications1.Development of devices that can be

controlled by thoughts.

2.If you think, a remote control is convenient,

imagine changing channels with your mind.

3.A more difficult task is interpreting the

brain signals for movement in someone who

can't physically move their own arm.

4.Once the basic mechanism of convertingthoughts to computerized or robotic action is

perfected, the potential uses for the technology

are almost limitless.


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BCI Applications

Medical applications:

Possibly only communication

channel for people sufferingfrom e.g. paraplegia,amyotrophia

Neuroprosthetics: Surgically implanted devices

used as replacement fordamaged neurons

Currently available: cochlear

implant (bionic ear)


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BCI Applications

Human enhancement

BCI that translates brainsignals into computer control

signals Exocortex (intelligence

booster)

Human manipulation Mind-Control

Neurohacking: unwantedreading of information from

the brain


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EEG

University college, London & TU Graz

VR application, controlling a wheelchair


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BCI Drawbacks There are about 100billionThere are about 100billion

neurons in a human brain.neurons in a human brain.Each neuron is constantlyEach neuron is constantlysending & receivingsending & receivingsignals through a WEB ofsignals through a WEB ofconnectionsconnections..

EEG measure tiny voltageEEG measure tiny voltagepotentials, sometimes apotentials, sometimes asimple as the blinkingsimple as the blinkingeyelids of the subject caneyelids of the subject cangenerate much Strongergenerate much Stronger

Signals.Signals. Some BCIs still require aSome BCIs still require a

wired connection to thewired connection to theequipment, & those thatequipment, & those thatare wireless require theare wireless require thesubject to carry asubject to carry a

computer that can weighcomputer that can weigharound 10pounds.around 10pounds.


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CONCLUSION

Brain-Computer Interface (BCI) is a

method of communication based on

voluntary neural activity generated by thebrain and independent of its normal output

pathways of peripheral nerves and

muscles.

The neural activity used in BCI can berecorded using invasive or noninvasive

techniques.


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REFERENCES

BCI-info.org

Brain- computer interface, www.wikipedia.org

http://en.wikipedia.org/wiki/ Brain- computer-interface#Invasive-BCIs

www.bci2000.org

Berlin Brain-Computer Interface

http://ida.first.fraunhofer.de/projects/bci/bbci-official/index-en.html

Lebedev MA, Nicoleis MA(2006), Brain-machine

interfaces: past, present and future.


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THANK YOU

FOR YOUR

ATTENTION

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