BRAIN COMPUTER INTERFACE

A

Presentation

On

Brain-Computer Interfacing

Prepared by Mr.Rushi Prajapati A.I.E.T. Jaipur

Saturday, April 8, 2023 1BCI

Scope of presentation

Basic IdeaGeneric BCI systemTypes of BCI systemEEG techniqueApplicationsAdvantagesDisadvantagesBCI InnovatorsFuture developments


MAN AND THE WORLD

Man interacts with the world using his five senses and limb movements


THOUGHTS faster than ACTIONS

Actions are mechanical movements while thoughts are electrical impulses.

Thoughts are faster than actions

So direct interaction with the world through thoughts would be faster.


Brain Computer Interface

Brain-computer interface (BCI) is a fast-growing emergent technology in which researchers aim to build a direct channel between the human brain and the computer.

BCI- The Ultimate in Human Computer Interfacing


Saturday, April 8, 2023 BCI 6

Components of BCI

Generation of signals from brain

Preprocessing,

Feature extraction,

Classification,

Device control.

Generic BCI System


EEG - Electro encephalography

ECoG - Electro cortico graphy

MEG - Magneto encephalo graphy

BOLD - Blood-Oxygen-Level-Dependent (signal)

MRI - Magnetic Resonance Imaging

Different neuroimaging methods are used to derive meaningful interpretations from the brain signals which are captured by microelectrodes:

signal extraction techniques


Types of BCI

Invasive-

inside grey matter of brain

Partially Invasive-

inside the skull but outside the grey matter

Non Invasive-

outside the skull, on the scalp


Invasive BCI S

Electrode inserted directly into grey matter

Highest quality signal can obtain

But are prone to scar-tissue build-up


Sensors Used in BCI-Microelectrodes

Silicon MicroelectrodeSaturday, April 8, 2023 11BCI

Wire-typeSilicon-basedCeramic-based Polyimide-based. Diagram of silicon-based

ACREO microelectrode arrays

Microelectrodes are used to capture electrical/magnetic signals of the brain.

Types:

Microelectrodes


Microwires emerging from the green and orange tubes connect to two arrays of 16 microelectrodes embedded in a small mat of clear, rubbery silicone - the larger, numbered electrodes are part of the patient’s original surgery (Photo: University of Utah Department of Neurosurgery) Saturday, April 8, 2023 13BCI

Implanted inside the skull but rest outside the grey matter of the brain

Produce better resolution signals than non-invasive BCIs where the bone tissue of the cranium deflects and deforms signals

Carry lower risk of forming scar-tissue in the brain than fully-invasive BCIs.

Partially Invasive BCIs


low signal quality due to electrodes are not directly interact with neurons

It is safest as no surgery required.

EEG is widely used for this technique

Non-Invasive BCIs


EEG Technique for BCI Electrodes attached to the

scalp

Electric signals of the brain

are amplified.

Transmitted to the computer

Software converts them into technical control signals ( computer commands)

These computer commands controls the computer.Saturday, April 8, 2023 16BCI

EEG WAVES

There are 5 major types of EEG waves

1. Delta Waves

2. Theta Waves

3. Alpha Waves

4. Beta Waves

5. Gamma Waves



Continuous Brain Waves Generally grouped by frequency: (amplitudes are about 100µV max)

Type Frequency Location Use

Delta <4 Hz everywhere occur during sleep, coma

Theta 4-7 Hz temporal and parietal correlated with emotional stress(frustration & disappointment)

Alpha 8-12 Hz occipital and parietal reduce amplitude with sensory stimulation or mental imagery

Beta 12-36 Hz parietal and frontal can increase amplitude during intense mental activity

Mu 9-11 Hz frontal (motor cortex) diminishes with movement or intention of movement

Lambda sharp, jagged

occipital correlated with visual attention

Vertex higher incidence in patients with epilepsy or encephalopathy

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


Electrode Placement

A more detailed view:


Area of implementation

Medical science Enabling disabled people

o Vision and hearing

o Paralysis treatment

o Prosthetic devices (legs, hands etc)

o Provide a means of communication to completely paralyzed patients

o Surgically implanted devices used as replacement for paralyzed patients


General application

Control a robot

Playing games

For physically weak persons to handle the computer

Cursor control

o Allow those with poor muscle control too communicate and control physical devices


Example of BCI application

A phsically handicapped man operates a BCI wheelchair


A single handed man interfaced with BCI

Japanese student walking in the virtual world with the character controlled by his brain waves.

More examples


ADVANTAGES

• BCIs will help creating a Direct communication between a human or animal brain and computers.

• Also it provides better living, more features, more advancement in technologies etc.

• High Precision (can be used reliably)

• Low bandwidth


Difficulty in Implementation of BCI:

COST require for BCI is very high.

It is RISKy, because it operates with brain.

Effective BCI technique requires invasive method.

Requires magnetically shielded room and special kind of helmet.

It is SLOW



BCI INNOVATORS

Pioneers

Nasa

Cyberkinetics neurotechnology system,

Japanese reaserch team

Future developments Better signal detection

Shortening training time

Improving learning (neurobiological and psychological basis)

New recording methods (NIRS, ECoG)

Broader range of applications (interface to commercially available assistive devices; treatment of diseases)


Conclusion

BCI is highly promising.

Provide high standard of living.

Extend our limits.

Impart a new level to the popular quote-

“I think therefore I am!”


ANY……???

Thank u…Saturday, April 8, 2023 30BCI

Date post:	31-Oct-2014
Category:	Education
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BRAIN COMPUTER INTERFACE

Education