Transcript Brain Wave Group 1

Brain Wave Group 1
Final Presentation
James Lin
Son Phan
Michael Oduselu
Purpose
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Research Thought Controlled
Applications
Observe how mind control can be used
Open new means of communication
Enhance quality of life and mental wellbeing
Potential Applications
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EEG Biofeedback
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Computer Control & Communication
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Control brain rhythms
Thought controlled systems
Entertainment & Virtual Reality
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Brain influcenced music and graphics
Adaptive Virtual Worlds
Applications Cont.
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Education and Research
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Brainwave experiments and labs
Military and Commercial Applications
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Monitor health and concisousness (NASA)
Controlling planes (Air Force)
Monitor consumer reactions to Ads and
Products
Research Background
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John Chapin
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Trained 6 rats to push a lever
Computer established pattern for pushing
lever
Mice pushed lever with thought
Gloria Calhoun
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Used brainwaves to pilot a flight simulator
EEG
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Stands for Electroencephalogram
Records bioelectric activity of brain
Monitors Frequencies from 0.5 to 20 Hz
Dependent on brain activity
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Age, arousal level, sleeping state, cerebral
dysfunctions
EEG Machines Available
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Brainmaster
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2-channel general purpose brainwave
monitor
Performs data storage, retrieval, real-time
signal processing, display, and feedback
WaveRider Jr
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Has Audiovisual feedback
More integrated and configured for easy
use but less sophisticated
EEG Machines Cont.
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POD
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EEG feedback machine
Used to improve self in areas ranging from
studying to golf
ProComp
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8 channel machine capable of EEG, EMG,
EKG, skin conductance, temperature, heart
rate, etc.
Expensive
Goals
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Tackle first task of reading brainwaves
Research and design EEG circuit
Assemble EEG circuit
Read brainwave on oscilloscope
Design Objective
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Build EEG Circuit
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Get parts
Use BrainMaster schematicsd
Test/Optimize EEG
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Test for heartbeat
Test for brainwave
Solder final circuit
Previous Design
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Amplifier didn’t work
Revised Design
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First step: EEG Monitor
Amplifier Schematic
Analysis Objectives
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Understanding Circuit
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Implement Circuit in P-spice
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Brain-Master Schematic
Part Functions
Ideal Op-Amps
AD620
OP90
Simulate and Examine Result
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Input and Output
Total Gain
Implement Circuit in P-spice
Simulate and Examine Result
Voltage
The Output Voltage
5
4
Voltage
3
2
1
0
1
10
100
Frequency
1000
Continued…
Gain
Total Amplifier Gain
2 10
4
1.5 10
4
1 10
4
Gain
2.5 10
4
5000
0
1
10
100
Frequency
1000
Specifications
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Type: differential
Gain: 20,000
Bandwidth: 1.7 – 34
Hz
Input Range 200uV
Output Range 4 V
CMRR >100dB
Other components
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Midpoint Voltage circuit
Other components
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Clean power source
Navigation: Waves vs Emotion
Heartbeat Test Results
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Breadboard circuit
measurement of
heart beat
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Second figure shows
a close up.
Compare with EKG
Assemble working circuit
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Solder circuit together
for better performance
Cleaner signal with
better electrodes and
pads
Flat signal = good sign
Signal from head
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Tested signal to amp
by biting down.
First capture shows
one bite.
Second capture
shows 3 bites.
Measure Brainwaves
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Results from head
show fluctuating
signal between 3
and 30 Hz.
Wave compared to
Brainmaster
screenshot.
Brain results cont.
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Waves look similar
Need to use filtering to
isolate frequency
energy of wave in a
specific time.
FFT Response
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FFT shows that range of
frequncies is 0 – 30 Hz
Closer insepection
shows a consistant
frequency spike around
10 Hz.
Frequency corresponds
to Alpha waves at front
of head.
Muscle induced response
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First capture shows
response of raising
eyebrows once.
Second capture
shows two eyebrow
raises.
Results continued
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Capture shows
signal created by a
hard blink
Conclusions
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EEG amplifier worked well in collecting
signals from the head.
Muscles signals were far easier to see
and create. No training involved.
Application such as a vehicle requires
instantaneous responses which muscle
signals may be better suited for.