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NeuroPhone : Brain-Mobile Phone
Interface using a wireless EEG
Headset
11-03-2014
Ilho nam
BCI (Brain–computer interface)
Science and technology of devices and
systems responding to neural and/or
cognitive processes, which enable their
user - who may have neural pathways that
have been damaged by amputation,
trauma or disease – to :
- Control their environment through reanimation of paralyzed limbs
- Control robotic devices
- Control computer devices
Emotiv Headset
•14 Channel EEG(Electroencephalograph)
•Designed for gaming,
•consumer biofeedback
•Affordable
–$399 basic headset
–$799 research edition
•Wireless, highly portable
Some Important Things they Tell you about
the Hardware
• Includes gyro output (captures head
movements)
• Samples at 128 Hz from a 2048Hz
internal rate
• Records voltage from easy to use
saline sponge sensors
• SDKs available in C++ & Python
Some Important Things they Don’t Tell you
about the Hardware
• Hair is a huge issue for getting a good
connection with the saline sensors.
• When batteries are low the sensors will
continue operating but start returning
increasingly random data (always keep
charged)
• For some reason you can’t record while
the device is plugged in
• Saline + exposed metal parts = corrosion
The NeuroPhone
A dial system for smartphones based on the P300 BCI, and using the EMOTIV headset
For EEG acquisition
The NeuroPhone : System architecture
EEG(Electroencephalograph)
• An EEG records electrical signals from
the brain
– Measures postsynaptic potentials of
neurons, via electrodes on the scalp
• An EEG detects the summed ionic
currents of thousands of pyramidal
neurons beneath each electrode.
• The signals relayed to the EEG are typically amplified 10,000
times and filtered.
Brain Wave Types
• EEGs record brain waves which are oscillating electrical voltages in the
brain measuring a few volts.
• There are six widely recognized brain waves:
– Delta: 1-4 Hz.
– Theta: 4-7 Hz.
– Alpha: 8-12 Hz.
– Mu rhythm is alpha-range activity that is seen over the
sensorimotor cortex.
– Beta:12-30 Hz.
– Gamma: 30–100 Hz.
The P300-based BCI
Imagine you are waiting in your car… The traffic light is red…
The P300-based BCI
The P300-based BCI
About 300ms after it turns green, a specific phenomenon
appears in your brain : the << P300 Potential >>
What Does the Signal Look Like?
Three Example Electrodes
The simplest BCI
EYES OPEN
EYES CLOSED
1 sec
Emotiv Epoc TestBench - 3D Brain
Activity Map Windows 8 EEG
http://youtu.be/Erb-N3OD6nc
EVALUATION
This preprocessing separately for all 6 stimuli corresponding
to the six images of the Dial Tim application.
The different time durations of data accumulation for averaging.
Contact pictures are flashed once every half a second in random order;
each of the 6 pictures has a 1/6 chance for each flash.
Conclusion
•
The EMOTIV headset, although cheap, is able to detect most important EEG
features exploited in medical Brain-Computer Interfaces
•
As all EGG system, EMOTIV is very sensitive to all kinds of artifacts. Some
solutions are emerging to address this issue but anyway, extra care should be
taken to avoid them as much as possible
Future?
• Whole brain coherence measures, recurrence analysis, synchrony,
entrainment etc….
• Sniffing packets could take on a very new meaning if brain-mobile phone
interfaces become widely used.
Thank you