li_zhuo_late_268457_10995134_ece5320-hw01-sensor-zhuo li

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ECE5320 Mechatronics

Assignment#01: Literature Survey on Sensors and Actuators

Topic: Brain Wave Sensor

Prepared by: Zhuo Li

Dept. of Electrical and Computer EngineeringUtah State University

3/9/2012


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10/14/2014 ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators

Slide-2

Outline

Reference list To probe further

Major applications

Working principle Typical setup

Major specifications

Advantages

Disadvantages

Products on-shelf

Outlook


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Slide-3

Reference list [1]. A. S. Hellera, Tom Johnstonec, A. J. Shackmana, S. N. Lighta, M. J. Petersond, G. G. Koldenb, N. H. Kalinb,

and R. J. Davidsona,Reduced capacity to sustain positive emotion in major depression reflects diminished

maintenance of fronto-striatal brain activation, PNAS, December 29, 2009, vol. 106, no. 52, 2244522450.

[2]. Yasui Y,A brainwave signal measurement and data processing technique for daily life applications,

NeuroSky White Paper, [online], http://www.ncbi.nlm.nih.gov/pubmed/19483376.

[3]. Hamalainen, M., Riitta, H., Ilmoniemi, R., Knuutila, J., and Lounasmaa, O. (1993).

Magnetoencephalographytheory, instrumentation, and applications to noninvasive studies of the working

human brain. Reviews of Modern Physics, 65(2), 414-497.

[4]. O'Regan, S., Faul, S., and Marnane, W. (2010).Automatic detection of EEG artefacts arising from head

movements. Engineering in Medicine and Biology Society (EMBC), 2010 Annual International Conference of the

IEEE, Buenos Aires, Argentina, August 31 - September 4, 2010, 6353-6356.

[5]. Fisher, R., Webber, W., Lesser, R., Arroyo, S., and Uematsu, S. (1992).High-frequency EEG activity at the

start of seizures. J Clin Neurophysiol, 9(3): 441-8.

[6]. Pfurtscheller G, Lopes da Silva FH (1999).Event-related EEG/MEG synchronization and desynchronization:

basic principles. Clin Neurophysiol, 110(11): 18421857.

[7]. Niedermeyer E. and da Silva F.L. (2004).Electroencephalography: Basic Principles, Clinical Applications,

and Related Fields. Lippincot Williams & Wilkins. ISBN 0781751268.

[8]. Yasuno et al (2008). The PET Radioligand [11C]MePPEP Binds Reversibly and with High Specific Signal to

Cannabinoid CB1 Receptors in Nonhuman Primate Brain. Neuropsychopharmacology, 33, 259-269.

[9]. Schlgl, A., Slater, M., & Pfurtscheller, G. (2002).Presence research and EEG Properties of EEG

recordings. Proceedings of the 5th Annual International Workshop PRESENCE. Porto, Portugal, October 9-11.
http://www.ncbi.nlm.nih.gov/pubmed/19483376http://www.ncbi.nlm.nih.gov/pubmed/19483376


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Slide-4

To explore further [i]. Droids sensor Blog, A Headset Sensor That Reads Your Brainwaves,

http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/

[ii]. TED Talk, A Headset Sensor That Reads Your Brainwaves,

http://www.ted.com/talks/view/lang/en//id/921

[iii]. Lab For Affective Neuroscience, Univ. of Wisconsin Madison,

http://psyphz.psych.wisc.edu/web/research.html

[iv]. EEG Used to Convict Murder Suspecthttp://medgadget.com/2008/09/eeg_used_to_convict_murder_suspect.html

[v]. Iyad Obeid, Temple Univ, TEDxPhilly, Mapping the brain,

http://www.youtube.com/watch?v=HV-k7EwZVNQ

[vi]. NeuroSky, http://www.neurosky.com/Default.aspx

[vii]. Mind Flex, Duel, http://mindflexgames.com/

[viii]. Uncle Milton, Star Wars Science, http://unclemilton.com/star_wars_science/

[ix]. National Center for Biotechnology Information,http://www.ncbi.nlm.nih.gov/guide/

[x]. Brain Waves & Brainwave entrainment, http://www.sleepwarrior.com/brain-waves-brainwave-

entrainment
http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://www.ted.com/talks/view/lang/en//id/921http://psyphz.psych.wisc.edu/web/research.htmlhttp://medgadget.com/2008/09/eeg_used_to_convict_murder_suspect.htmlhttp://www.youtube.com/watch?v=HV-k7EwZVNQhttp://www.neurosky.com/Default.aspxhttp://mindflexgames.com/http://unclemilton.com/star_wars_science/http://www.ncbi.nlm.nih.gov/guide/http://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.sleepwarrior.com/brain-waves-brainwave-entrainmenthttp://www.ncbi.nlm.nih.gov/guide/http://unclemilton.com/star_wars_science/http://mindflexgames.com/http://www.neurosky.com/Default.aspxhttp://www.youtube.com/watch?v=HV-k7EwZVNQhttp://www.youtube.com/watch?v=HV-k7EwZVNQhttp://www.youtube.com/watch?v=HV-k7EwZVNQhttp://medgadget.com/2008/09/eeg_used_to_convict_murder_suspect.htmlhttp://psyphz.psych.wisc.edu/web/research.htmlhttp://www.ted.com/talks/view/lang/en//id/921http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/http://droidsensors.com/2010/07/a-headset-sensor-that-reads-your-brainwaves/


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Slide-5

Major applications

Ordinary life Smart home

Medical

Assistant devices for handicapped

Clinical examination Depression, sleep disorder analysis [1] [iii]

Academic research

Exploring the brain

Entertainment Game console

Security

Convict criminal suspect by Brain Electrical Oscillations Signature test (BEOS) [iii]

Fig5. [x]


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Introduction

What are brain waves? Allbrain cells communicate via electrical signals. Ones brain contains about 100 billion

neurons, well over the number of stars in our galaxy. Each neuron is connected to about 10,000

other neurons, making for about 100 to 500 trillion neuron-to-neuron connections in the

brain. [x]

Our current technology cannot see whats happening at the neuron level. Theyre just too

small, and theres just too many of them. However, our technologycansee overallpatternsofbrain activity. [x]

Neurons firing

Brainwave Entrainment

Also called brainwave synchronization. It purportedly depends upon a "frequency following"

response on the assumption that the human brain has atendency to change its dominant EEG

frequency towards the frequency of a dominantexternal stimulus. [Wikipedia.org] One study showed that when two people are in the same room, their brainwaves and heartbeats

become entrainedthat is, their brainwaves become matched up in frequency. [x]

Here is a video of TED talk by Keith Barry demonstrating Brainwave Entrainment

http://www.ted.com/talks/keith_barry_does_brain_magic.html


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Introduction

Methods to study brain function Functional magnetic resonance imaging (fMRI)

Nuclear magnetic resonance spectroscopy ()

Electroencephalography (EEG)

Magnetoencephalography

Electrocorticography (ECG)

Brain-computer interface (BMI)

often called a mind-machine interface (MMI), is a direct communication pathway between the

brain and an external device. BCIs are often directed at assisting, augmenting, or repairing

human cognitive or sensory-motor functions. [Wikipedia.rog]

Brain wave sensor

Brain wave sensor is the sensor to capture the signals generated by brain activities.

Data acquisition device implementing EEG measurement is nothing but a net of voltmeters.

Nowadays, the brain wave sensor refers more on the data fusion and processing technology than

sensing itself. Most products are turnkey (whole set) involving sensing with applications.


Slide-7


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Working principle Electroencephalography (EEG)

An electroencephalogram is a test that measures and records the electrical activity of ones

brain. [Wikipedia.org]

Source of EEG activity

The brain's electrical charge is maintained by billions of

neurons. Neurons are electrically charged (or "polarized")by membrane transport proteins that pump ions across their

membranes. Neurons are constantly exchanging ions with

the extracellular milieu, for example to maintain resting

potential and to propagate action potentials. Ions of like

charge repel each other, and when many ions are pushed

out of many neurons at the same time, they can push their

neighbors, who push their neighbors, and so on, in a wave.

This process is known as volume conduction.

When the wave of ions reaches the electrodes on the scalp, they can push or pull electrons on the metal on the

electrodes. The difference in push or voltage between any two electrodes can be measured by a voltmeter.

Recording these voltages over time gives us the EEG. [Wikipedia.org]


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Fig7. An EEG recording net. [iii]


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Working principle

EEG Wave patterns [Wikipedia.org] Deltais the frequency range up to 4 Hz. It tends to be the highest in amplitude and the slowest

waves.

Thetais the frequency range from 4 Hz to 7 Hz. Theta is seen normally in young children. It

may be seen in drowsiness or arousal in older children and adults; it can also be seen in

meditation.

Alphais the frequency range from 8 Hz to 12 Hz. Hans Berger named the first rhythmic EEGactivity he saw as the "alpha wave".

Betais the frequency range from 12 Hz to about 30 Hz. It is seen usually on both sides in

symmetrical distribution and is most evident frontally. Beta activity is closely linked to motor

behavior and is generally attenuated during active movements. [6]

Gammais the frequency range approximately 30100 Hz. Gamma rhythms are thought to

represent binding of different populations of neurons together into a network for the purpose ofcarrying out a certain cognitive or motor function. [7]

Muranges 813 Hz., and partly overlaps with other frequencies. It reflects the synchronous

firing of motor neurons in rest state.


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Working principle

EEG Wave patterns


Slide-10

Deltawaves

Thetawaves

Alphawaves

Sensorimotor rhythm aka murhythm.

Betawaves

Gammawaves

Fig8. Brain wave patters. [Wikipedia.org]


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Typical setup

Please refer to the video in [ii]


Slide-12


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Advantages

EEG based brain wave sensor EEG sensors can be used in more places than fMRI, SPECT, PET, MRS, or MEG,

as these techniques require bulky and immobile equipment. For example, MEG

requires equipment consisting of liquid helium-cooled detectors that can be used

only in magnetically shielded rooms, altogether costing upwards of several million

dollars[3]; and fMRI requires the use of a 1-ton magnet in, again, shielded room.

EEG has higher temporal resolution - milliseconds, rather than seconds - it can, in

fact, take as many as 2000 samples per second [5] Only MEG rivals these speeds.[3]

EEG is relatively tolerant of subject movement, unlike all other neuroimaging

techniques. There even exist methods for minimizing, and even eliminating

movement artefacts in EEG data [4]


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Disadvantages

EEG based brain wave sensor Significantly lower spatial resolution compared to other measuring approaches.

EEG determines neural activity that occurs below the upper layers of the brain (the

cortex) very poorly

Unlike PET and MRS, cannot identify specific locations in the brain at which

various neurotransmitters, drugs, etc. can be found. [8] Often takes a long time to connect a subject to EEG, as it requires precise placement

of dozens of electrodes around the head and the use of various gels, saline solutions,

and/or pastes to keep them in place. While the length of time differs dependent on

the specific EEG device used, as a general rule it takes considerably less time to

prepare a subject for MEG, fMRI, MRS, and SPECT.

Signal-to-noise ratio is very poor, so sophisticated data analysis and relatively large

numbers of subjects are needed to extract useful information from EEG. [9]


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On-shelf Products

NeuroSky [vi] MindSet Headset

MindWave Headset w/ Education Bundle

MindBand

ThinkGear AM

Brain Athlete


Slide-15

Fig13-1. NeuroSky ThinkGear AM. [vi]

Fig13-2. NeuroSky Brain Athlete. [vi]


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NeuroSky MindSet Overview [vi]

The MindSet was the first mass market EEG headset when it debuted in 2009. The device consists of earphone, a microphone, and a sensorarm. The headsets reference and ground electrodes are on the ear phones and the EEGelectrode is on the end of the sensor arm, sitting on the

forehead above the eye. Not only can it collect research-grade EEG data, but it features a set of high-quality Bluetooth enabled wireless headphones

complete with microphone. The MindSet is versatile, compact, and portable. It is an excellent choice for gaming, research, or public installations.

Measures:

Raw-Brainwaves

EEG power spectrums (Alpha, Beta, etc.)

eSense meter for Attention and Meditation

Physical:

190g weight

Length 21cm X width 17.5cm X height 5.0cm

Signal and EEG:

Maximum signal input range: 1mV pk-pk

Hardware filter range: 3Hz to 100Hz

MS001: includes 60Hz environmental AC noise filtering

MS002: includes 50Hz environmental AC noise filtering

Amplification gain: 2000x

ADC resolution: 12 bits (-2048 to 2047)

Sampling rate: 512Hz

eSense interpretation update rate: 1Hz 0% byte loss (ie packet loss)

1Hz eSense interpretation rate

UART Baudrate: 57,600 Baud

SPP through put: 9600 Baud

S/N ratio: >70dB

Class 2 Bluetooth Radio Range: 10 m 6dBm RF max power

250kbit/s RF data rate

On-shelf Products


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Fig. NeuroSky MindSet Headset


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On-shelf Products

Mind Flex Duel [vii]Brainwave entertainment/toy


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Fig15. Mind Flex Duel. [vii]


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On-shelf Products

Uncle Milton Star Wars Science [viii]Brainwave entertainment/toy


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Fig16. Uncle Milton Star Wars Science [viii]


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Outlook

Since brainwaves are weak electric signals, contactless monitoring is difficult.Hence, contactless brainwave sensor appears technically hard but appealing.


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