brain computer interface ppt
DESCRIPTION
TRANSCRIPT
Brain Computer Interface
By,
Ajay George
S8 - IT
04/08/23 IT Department, JECC
What is BCI
• Direct communication pathway between the brain and an external device
• Reads electrical signals from brain
• Signals translated into a digital form
04/08/23 IT Department, JECC
History
• Research started from 1970
• BCI Project by Jacques Vidal
• Implanting simple BCI sensors within rats, mice, monkeys, and humans.
04/08/23 IT Department, JECC
History
• 1990 - implanting an electrode in the motor cortex of a paralyzed patient.
• Makes the patient communicate by moving a cursor.
• 1999 – Trained rats to use their brain signals to move a robotic water-dispensing arm.
04/08/23 IT Department, JECC
How BCI work
04/08/23 IT Department, JECC
How BCI work
04/08/23 IT Department, JECC
How BCI work
• Uses optical nerves for image input
• Camera input directed to brain
04/08/23 IT Department, JECC
Types of BCI
• Invasive• Partially Invasive• Non-Invasive
04/08/23 IT Department, JECC
Invasive BCI
04/08/23 IT Department, JECC
• Targeted for people with paralysis
• Implanted directly into the grey matter
• Produce the highest quality signals
• scar-tissue build-upJens Naumann, a man with acquired blindness, being
interviewed about his vision
Partially Invasive BCI
04/08/23 IT Department, JECC
• BCI devices are implanted inside the skull
• produce better resolution signals
• lower risk of forming scar-tissue
Cathy Hutchinson, who was one of the first persons to have a
direct connection between her brain and a computer implanted
Non-Invasive BCI
04/08/23 IT Department, JECC
• Easy to wear• produce poor signal• dispersing the
electromagnetic waves created by the neurons
Recording Domains
04/08/23 IT Department, JECC
Electrocorticography(ECoG )
04/08/23 IT Department, JECC
• Pioneered in the early 1950s• Measures the electrical activity of the brain• Taken from beneath the skull• Embeds electrodes in a plastic bag placed
above cortex• A surgical incision is required
MRI technology
04/08/23 IT Department, JECC
• Uses brain signals to control
• Detects the subject’s brain signals and sends the MRI signals over Ethernet cables, via TCP/IP, to a computer.
MRI technology
04/08/23 IT Department, JECC
Magnetoencephalography (MEG)
04/08/23 IT Department, JECC
• Magnetic Field of 10-15 T to 10-13 T
• S.Q.U.I.D Sensors are required
• Shielded room is needed
Electroencephalography (EEG)
04/08/23 IT Department, JECC
• Recording of electrical activity along the scalp
• Measures voltage fluctuations resulting from ionic current.
• Fine temporal resolution• Ease of use, portable and low set-up cost
Electroencephalography (EEG)
Emotiv Cap, 14 Electordes,
Wireless connection. Commercial BCI from NeuroSky
04/08/23 IT Department, JECC
Electroencephalography (EEG)
04/08/23 IT Department, JECC
P300
Electroencephalography (EEG)
04/08/23 IT Department, JECC
• Described in frequency ranges• Delta ( ) < 4 Hz. Most apparent in deep δ
sleep states.• Theta ( ) waves 4-8 Hz, appear in a relaxed θ
state and during light sleep and meditation.
Electroencephalography (EEG)
04/08/23 IT Department, JECC
• Alpha ( ) waves 8-12 Hz, associated with αmeditation and relaxation.
• Beta ( ) 13-30 Hz waves, connected to βalertness and focus.
• Gamma ( ) waves > 30 Hz, rγ elated to subjective awareness
Electroencephalography (EEG)
04/08/23 IT Department, JECC
System Block Diagram
Processes
04/08/23 IT Department, JECC
• Bandpass Filter - to filter out frequencies that do not fall within the α and β ranges.
• Related to senseorimotor activities
• Common Spatial Patterns (CSP) – enhances the discriminability between classes.
Processes
04/08/23 IT Department, JECC
Feature Extraction methods used to collect useful vectors
• Log Variance• Power Density Estimation (PSD)• Wavelet Packet Decomposition (WPD)
Processes
04/08/23 IT Department, JECC
• Principle Component Analysis (PCA) -reduce the dimensionality of the feature vector
• Classification Method - to build classifier which discriminate between labels. Linear Discriminant Analysis (LDA) is used
Electroencephalography (EEG)
04/08/23 IT Department, JECC
Applications
04/08/23 IT Department, JECC
• Medicinal• Military• Bioengineering• Brain operated wheelchair• Multimedia and Virtual Reality
Conclusion
04/08/23 IT Department, JECC
• Enables people to communicate and control appliances with use of brain signals
• Open gates for disabled people.• Development of new brain imagining
techniques• Numerous future applications
Bibliography
04/08/23 IT Department, JECC
• Toward Inexpensive and Practical Brain Computer Interface by Hamzah S. AlZu’bi Nayel S. Al-Zubi Waleed Al-Nuaimy
• Robot Navigation using Brain-Computer Interfaces by Athanasios Vourvopoulos and Fotis Liarokapis
Bibliography
04/08/23 IT Department, JECC
• A general framework of Brain-Computer Interface with Visualization and Virtual Reality Feedback by Gufei Sun, Kuangda Li, Xiaoqiang Li, Bofeng Zhang, Shizhong Yuan, Gengfeng Wu
Thank You
04/08/23 IT Department, JECC