NeuroPhone : Brain-Mobile Phone Interface using a wireless EEG Headset

11-03-2014Ilho 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 re-animation of paralyzed limbs

- Control robotic devices- Control computer devices

•14 Channel EEG(Electroencephalograph)

•Designed for gaming, •consumer biofeedback

•Affordable– $399 basic headset– $799 research edition

• Wireless, highly portable

Emotiv Headset

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 NeuroPhoneA dial system for smartphones based on the P300 BCI, and using the EMOTIV headsetFor 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 BCIImagine you are waiting in your car… The traffic light is red…

The P300-based BCI

The P300-based BCIAbout 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 BCIEYES CLOSEDEYES OPEN

1 sec

http://youtu.be/Erb-N3OD6nc

Emotiv Epoc TestBench - 3D Brain Activity Map Windows 8 EEG

EVALUATION

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.

This preprocessing separately for all 6 stimuli correspondingto the six images of the Dial Tim application.

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