09-05-2011, 03:12 PM
BCI ppt.ppt (Size: 4.3 MB / Downloads: 121)
BRAIN COMPUTER INTERFACE(BCI)
Brain Computer Interface
A brain-computer interface is a direct communication pathway between a human or animal brain ( or brain cell culture) and an external device.
Sometimes called a direct neural interface or a brain machine interface (BMI).
Motivation for BCI Research
In USA, more than 200,000 patients live with the motor sequelae (consequences) of serious injury. There are two ways to help them restore some motor function:
Repair the damaged nerve axons.
Build neuroprosthetic device.
Detecting neural activity
Invasive BCI
Invasive BCI are directly implanted into the grey matter of the brain during neurosurgery.
They produce the highest quality signals of BCI devices .
Prone to building up of scar-tissue
Targeted repairing damaged sight and providing new functionality to paralyzed people (neuroprosthetics).
Detecting neural activity
Non Invasive BCI
Neuroimaging technologies as interfaces are used.
Signals recorded in this way have been used to power muscle implants and restore partial movement in an experimental volunteer.
Non-invasive implants produce poor signal resolution .
EEG
Using BCI
Neuron spike based BCI
High speed real time control
Precise control of movement
Invasive
High risk for clinical application
Working of Simple BCI
BCI Methods
P300 detection
How can you type words by mind?
The P300 (P3) wave is an event related potential (ERP) which can be recorded via electroencephalography (EEG) as a positive deflection in voltage at a latency of roughly 300 ms in the EEG.
EEG mu-Rhythm Conditioning
VEP Detection
Experiment Design
Alphabet row/column was flashing randomly on the computer screen
Human subject was gazing at the screen
Human EEG was recorded simultaneously
P300 components in EEG was extracted in real time for letter guess
EEG amplifier Human
subject Visual feedback
Experiment Design
Application
Artificial Sensory channel
Artificial Hearing
Artificial Vision
Artificial Motor Channel
3. Neural Disorder Control Parkinson’s disease Seizure prediction and control
Artificial Sensory channel
Artificial Motor Channel
Neural Disorder Control Parkinson’s disease Seizure prediction and control
Future : Silicon Cognition
Advantages
BCIs will help creating a Direct communication pathway between a human or animal brain and any external devices like computers.
BCI has increased the possibility of treatment of disabilities related to nervous system along with the old technique of Neuroprosthetics.
Techniques like EEG, MEG and neurochips have come into discussions since the BCI application have started developing.
This has provided a new work area for scientists and researchers around the world.
Disadvantages
In case of Invasive BCI there is a risk of formation of scar tissue.
There is a need of extensive training before user can use techniques like EEG
BCI techniques still require much enhancement before they can be used by users as they are slow.
Ethical implications of BCI will arise in future
BCI techniques are costly. It requires a lot of money to set up the BCI environment.
Conclusion
Brain-Computer Interface (BCI) is a method of communication based on voluntary neural activity generated by the brain and independent of its normal output pathways of peripheral nerves and muscles.
The neural activity used in BCI can be recorded using invasive or noninvasive techniques.
We can say as detection techniques and experimental designs improve, the BCI will improve as well and would provide wealth alternatives for individuals to interact with their environment.