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Introduction to Brain-Computer Interface (BCI) | PDF
Brain
Computer
Interface
Isuru Jayarathne
University of Aizu
10/01/2018
Content
◎ BCI related applications
◎ Biosignals
◎ What is BCI
◎ Related subject areas
◎ Technologies
◎ Basics of EEG
◎ Brain lobes
◎ Electrode placement
2
◎ Frequency bands
◎ Basic flow
◎ EEG devices
◎ Artifacts
◎ Pre-Processing
◎ Feature extraction
◎ Pattern recognition
◎ More...
BCI Applications
◎ Controlling robots
3
BCI Applications
◎ Controlling drones
4
BCI Applications
◎ BCI with VR
5
BCI Applications
◎ BCI speller
6
BCI Applications
◎ BCI mouse
7
BCI Applications
◎ BCI exoskeleton
8
BCI Applications
◎ NeuroPhone
9
BCI Applications
◎ Brain signal-based authentication system
◎ Epilepsy seizure detection
◎ Meditation applications
◎ Educational applications
◎ Emotion classification
◎ Sleep disorder studies
◎ etc.
10
Biosignals
◎ Signals that can be continually measured and
monitored from the living being
◎ Can be electrical or non-electrical
○ Electrocardiogram (ECG)
○ Electroencephalogram (EEG)
○ Magnetoencephalogram (MEG)
○ Electromyogram (EMG)
○ Electrooculography (EOG)
○ Galvanic skin response (GSR)
○ Mechanomyogram (MMG)
11
What is BCI
◎ Direct communication between enhanced brain and
an external device.
◎ Methods
○ Invasive
○ Partially invasive
○ Non-invasive
12
Related subject areas
◎ Neuroscience
◎ Digital Signal Processing (DSP)
◎ Digital Image Processing (DIP)
◎ Machine Learning (ML) - in the most cases
13
Technologies
◎ fMRI: functional Magnetic Resonance Imaging
◎ EEG: Electroencephalography
◎ MEG: Magnetoencephalography
◎ NIRS: Near-infrared spectroscopy
14
Basics of EEG
◎ Electroencephalography (EEG): Electrophysiological
monitoring method to record electrical activity of
one’s brain
◎ Subtle electric field is generated by neurons
◎ EEG electrodes can capture the electric field of group
of neurons
15
Brain lobes
◎ Four brain lobes
○ Frontal
○ Parietal
○ Temporal
○ Occipital
16
Electrode placement
◎ 10-20 system
◎ 10-10 system or 10%
◎ 10-5 system
17
Electrode placement (Cont.)
◎ 10-20 system & 10% system
18
Basic flow
19
Data
Collection
Pre-Processing
Feature
Extraction
Classification
EEG devices
◎ Clinical- and consumer-grade devices are available
◎ Two types of electrodes, Wet and dry
◎ Comes with different number of electrodes
20
EEG devices (Cont.)
21
Device Number of Channels Electrode type
NeuroSky Mindwave 1 Dry
Muse 2 Dry
EMOTIV Insight 5 Dry
EMOTIV Epoc+ 14 Wet
OpenBCI 16 Dry
mBrainTrain 24 Wet
ENOBIO 32 32 Dry
Cognionics Mobile- 72 64 Dry
Pre-Processing
◎ Filtering
○ Separate frequency bands
◎ Artefact removal
○ Blind Source Separation (BSS)
◎ Fourier Transform/Fast Fourier Transform
22
Frequency bands
◎ Delta: 1 - 4 Hz
○ Highest amplitude
○ Presents during deep sleep
◎ Theta: 4 - 8 Hz
○ Focused attention, memory recall (frontal)
◎ Alpha: 8 - 13 Hz
○ Mental and physical relaxation (occipital, parietal)
23
Frequency bands (Cont.)
◎ Beta: 13 - 30 Hz
○ Active thinking, active concentration
◎ Gamma: < 30 Hz
○ Binding of different populations of neurons
24
Artifacts
◎ EOG, EMG, ECG interferes the EEG signals
◎ Impact of power line noise
◎ Head swaying and swinging
To remove
◎ Record other biosignals as well
◎ Filtering
◎ Record gyroscope data
25
Feature extraction
◎ Power Spectral Density (PSD)
◎ Common Spatial Patterns (CSP)
◎ Autoregressive Coefficients (AR)
◎ Frontal Asymmetry
◎ Inter-Hemispheric Power Difference
◎ Inter-Hemispheric Linear Complexity
◎ Spectral Coherence
◎ Peak frequency
26
Pattern recognition/Machine Learning
◎ Linear Discriminant Analysis
◎ Quadratic Discriminant Analysis
◎ Support Vector Machine (Linear, Quadratic, Cubic,
Gaussian)
◎ k-Nearest Neighbour
◎ Deep Learning techniques
27
References
◎ IMOTION EEG Pocket Guide (url: https://imotions.com/eeg-guide-ebook/)
◎ Wikipedia
◎ https://www.youtube.com/watch?v=Zd9WhJPa2Ok
◎ https://youtu.be/hLjxMjBlB9k
◎ https://www.youtube.com/watch?v=yamA5yM2h0Q
◎ https://www.youtube.com/watch?time_continue=87&v=tc82Z_yfEwc
◎ https://youtu.be/wKDimrzvwYA
◎ https://youtu.be/LvJk420Bbts
◎ https://youtu.be/jeLghZ8GASA
◎ www.emotiv.com
◎ www.choosemuse.com
28
Other interesting stuffs
◎ rTMS, tDCS
◎ Neuromorphic chips
◎ Quantum Computers (ibm.biz/qx-introduction)
◎ Augmented Reality (AR) and Virtual Reality (VR) with
HMDs and smart glasses
29
30
Thanks!
Any questions?
Blog: www.i-linkz.net

Introduction to Brain-Computer Interface (BCI)

  • 1.
  • 2.
    Content ◎ BCI relatedapplications ◎ Biosignals ◎ What is BCI ◎ Related subject areas ◎ Technologies ◎ Basics of EEG ◎ Brain lobes ◎ Electrode placement 2 ◎ Frequency bands ◎ Basic flow ◎ EEG devices ◎ Artifacts ◎ Pre-Processing ◎ Feature extraction ◎ Pattern recognition ◎ More...
  • 3.
  • 4.
  • 5.
  • 6.
  • 7.
  • 8.
  • 9.
  • 10.
    BCI Applications ◎ Brainsignal-based authentication system ◎ Epilepsy seizure detection ◎ Meditation applications ◎ Educational applications ◎ Emotion classification ◎ Sleep disorder studies ◎ etc. 10
  • 11.
    Biosignals ◎ Signals thatcan be continually measured and monitored from the living being ◎ Can be electrical or non-electrical ○ Electrocardiogram (ECG) ○ Electroencephalogram (EEG) ○ Magnetoencephalogram (MEG) ○ Electromyogram (EMG) ○ Electrooculography (EOG) ○ Galvanic skin response (GSR) ○ Mechanomyogram (MMG) 11
  • 12.
    What is BCI ◎Direct communication between enhanced brain and an external device. ◎ Methods ○ Invasive ○ Partially invasive ○ Non-invasive 12
  • 13.
    Related subject areas ◎Neuroscience ◎ Digital Signal Processing (DSP) ◎ Digital Image Processing (DIP) ◎ Machine Learning (ML) - in the most cases 13
  • 14.
    Technologies ◎ fMRI: functionalMagnetic Resonance Imaging ◎ EEG: Electroencephalography ◎ MEG: Magnetoencephalography ◎ NIRS: Near-infrared spectroscopy 14
  • 15.
    Basics of EEG ◎Electroencephalography (EEG): Electrophysiological monitoring method to record electrical activity of one’s brain ◎ Subtle electric field is generated by neurons ◎ EEG electrodes can capture the electric field of group of neurons 15
  • 16.
    Brain lobes ◎ Fourbrain lobes ○ Frontal ○ Parietal ○ Temporal ○ Occipital 16
  • 17.
    Electrode placement ◎ 10-20system ◎ 10-10 system or 10% ◎ 10-5 system 17
  • 18.
    Electrode placement (Cont.) ◎10-20 system & 10% system 18
  • 19.
  • 20.
    EEG devices ◎ Clinical-and consumer-grade devices are available ◎ Two types of electrodes, Wet and dry ◎ Comes with different number of electrodes 20
  • 21.
    EEG devices (Cont.) 21 DeviceNumber of Channels Electrode type NeuroSky Mindwave 1 Dry Muse 2 Dry EMOTIV Insight 5 Dry EMOTIV Epoc+ 14 Wet OpenBCI 16 Dry mBrainTrain 24 Wet ENOBIO 32 32 Dry Cognionics Mobile- 72 64 Dry
  • 22.
    Pre-Processing ◎ Filtering ○ Separatefrequency bands ◎ Artefact removal ○ Blind Source Separation (BSS) ◎ Fourier Transform/Fast Fourier Transform 22
  • 23.
    Frequency bands ◎ Delta:1 - 4 Hz ○ Highest amplitude ○ Presents during deep sleep ◎ Theta: 4 - 8 Hz ○ Focused attention, memory recall (frontal) ◎ Alpha: 8 - 13 Hz ○ Mental and physical relaxation (occipital, parietal) 23
  • 24.
    Frequency bands (Cont.) ◎Beta: 13 - 30 Hz ○ Active thinking, active concentration ◎ Gamma: < 30 Hz ○ Binding of different populations of neurons 24
  • 25.
    Artifacts ◎ EOG, EMG,ECG interferes the EEG signals ◎ Impact of power line noise ◎ Head swaying and swinging To remove ◎ Record other biosignals as well ◎ Filtering ◎ Record gyroscope data 25
  • 26.
    Feature extraction ◎ PowerSpectral Density (PSD) ◎ Common Spatial Patterns (CSP) ◎ Autoregressive Coefficients (AR) ◎ Frontal Asymmetry ◎ Inter-Hemispheric Power Difference ◎ Inter-Hemispheric Linear Complexity ◎ Spectral Coherence ◎ Peak frequency 26
  • 27.
    Pattern recognition/Machine Learning ◎Linear Discriminant Analysis ◎ Quadratic Discriminant Analysis ◎ Support Vector Machine (Linear, Quadratic, Cubic, Gaussian) ◎ k-Nearest Neighbour ◎ Deep Learning techniques 27
  • 28.
    References ◎ IMOTION EEGPocket Guide (url: https://imotions.com/eeg-guide-ebook/) ◎ Wikipedia ◎ https://www.youtube.com/watch?v=Zd9WhJPa2Ok ◎ https://youtu.be/hLjxMjBlB9k ◎ https://www.youtube.com/watch?v=yamA5yM2h0Q ◎ https://www.youtube.com/watch?time_continue=87&v=tc82Z_yfEwc ◎ https://youtu.be/wKDimrzvwYA ◎ https://youtu.be/LvJk420Bbts ◎ https://youtu.be/jeLghZ8GASA ◎ www.emotiv.com ◎ www.choosemuse.com 28
  • 29.
    Other interesting stuffs ◎rTMS, tDCS ◎ Neuromorphic chips ◎ Quantum Computers (ibm.biz/qx-introduction) ◎ Augmented Reality (AR) and Virtual Reality (VR) with HMDs and smart glasses 29
  • 30.