brain computer interface ppt
TRANSCRIPT
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