THE DEVELOPMENT OF PORTABLE EEG DEVICES FOR THE TREATMENT AND DIAGNOSIS

OF MENTAL AND NEUROLOGICAL DISORDERS

Personal Neuro Devices Inc.

Outline

1) Regular EEG – basic primer

2) Mechanisms behind EEG – how it works

3) Current uses of EEG

4) Future direction of EEG

5) Current state of personal EEG, and its limitations

6) Demo of personal EEG device

7) Introspect (portable personal EEG)

8) Potential uses of Introspect

9) Conclusion (and summary)

1) Regular EEG – basic primer Device for

determining what areas on the surface of the brain are displaying activity

Uses electrodes placed around the scalp to pick up electrical activity produced by neurons in the brainAction potentials

Action potential

2) Mechanisms behind EEG: how it works Neurons always produce

electrical activity When excited, neural membrane

transport proteins pump ions through cell membraneBiggest effect in action potential

Released ions then push nearby ions in extracellular fluidContinues indefinitely, in wavesThese waves eventually reach the

scalp, where they can be detected through their magnetic “push” on the metal of the electrodes

Called volume conductionA membrane transport protein

3) Current uses of EEG Medical diagnostics in a

lab or clinicEpilepsyBrain death testingSleep disordersPhotosensitivityADHDNarcolepsyVarious brain cancersEncephalitis

Coma patient being tested for brain death

Current uses of EEG Continuous

monitoring for seizures in ICU

Depth of anaesthesia monitoring

Evaluation of head injuriesFinds white matter

damageFinds brain regions

that have become isolated

EEG bispectral index monitor for monitoring brain activity during surgery

Current uses of EEG Neurofeedback

Patients trained to directly alter their EEG output

Still experimentalUsed to a small

degree for epilepsy, depression, addictive disorders, and anxiety

Primarily used for treating ADHD○ Easiest use, as beta

waves are strongly associated with attention EEG wave patterns, from top to bottom: beta, alpha,

theta, stage 2 sleep, and delta (stage 4 sleep)

Example of a neurofeedback game tailored to young children with ADHD

Current uses of EEG Brain function research, when some or all of the following are

required: High temporal resolution – allows for study of the stages of brain

processing, rather than just the activity that results at the end of a task Study of subjects unable to give direct responses Monitoring of sleep Longer-term monitoring than is feasible with fMRI Study in an environment other than a clinic or lab

EEG in use at a sleep lab

4) Future direction of EEG

MEG is considerably better than EEG for most of EEG’s current usesCost and device size is

all that prevents MEG from entirely supplanting EEG for these particular purposes, but this is dropping

A magnetoencephalography (MEG) device

Future direction of EEG However, MEG is not

the end for EEG Not every use of EEG can

be replaced by MEGAlso, two new major

directions EEG is currently taking that no other existing neuroimaging technique could go:○ Personal neuroimaging○ Portable neuroimaging

MEG could never be used in research like this

5) Personal EEG EEG has become

more accessible to the general public in recent yearsMuch lower quality than

professional equipment○ However, other

advantagesMost simply use EEG

as a component in certain toys and games○ Jedi Force Trainer○ Mindflex

Mindflex

I can lift a ball! $100 well spent.

Mindflex

Personal EEG 3 companies making

programmable EEG platforms - primarily for the purpose of brain-computer interfacing, each with one major device on the marketNeurosky’s Think-Gear

○ Simple device for lay public and software developers

○ 6 electrodes

Neurosky’s Think-gear

Personal EEG

OCZ Technology’s Neural Impulse Actuator○ Weakest of the

customizable commercial BCI headsets

○ Only 3 electrodes○ Not really EEG,

though marketed as such

Neural Impulse Actuator

Neural Impulse Actuator in use

Personal EEG

Emotiv Inc.’s EPOC Neuroheadset○ More advanced

16 electrodes

○ Still a BCI○ Still primarily for games

and software○ However, more

conducive to therapeutic applicationsParaplegic using Emotiv to move wheelchair

6) Limitations of current personal EEG

Complete focus on brain-controllers, rather than gaining information about the user

Lose connection easily Not really portable Small number of

electrodes Clunky

For the look that screams “don’t bother talking, I’m reading your thoughts directly”, why not pick

up a Neurosky Mindset?

Personal Neuro Devices: Introspect

7) Introspect Will be commercially

availableLower costMarketed to public

Truly portableActive electrodes

○ Improves resolution, sensitivity, resistance to movement noise

Exterior mesh that clips to a series of hats○ Hiring fashion design

company to make catalogue of hats to fit over Introspect

For all you know, Indiana Jones could be wearing a portable

EEG device

Introspect Level of sensitivity

equivalent to Emotiv Modified 10-20 electrode

placement system Open-source API

Applications open to creation by outside developers

Easier to hydrate electrodes Will run tubes through arms

attaching to electrodes; pressing pump will transport fluid to back of electrode pads – will soak through

10-20 system

How active electrode system works – stepwise (very simplified):1) Removes noise caused by circuits themselves2) Ups voltage of incoming signals in relation to one another (multiplies differences between nearby electrode inputs) – makes signal larger without distorting waveform3) Rejects all wavelengths known not to be associated with EEG information (which represent some sort of noise)4) Microcontroller in electrode transmits binary data corresponding to wave inputs5) Base unit receives signal, and sends it through USB to the portable device

8) Potential uses - Epilepsy Epilepsy

Advance seizure detection○ Prevention of secondary injuries○ Stop seizure before it hits

Early drug administration, IE midazolamElectrical stimulation

○ Effective algorithms already existAutoregressive models and support vector

machines- Can get 100% sensitivity, low false alarm rate

Schematic representation of combined SVM andAR model seizure prediction system

Midazolam – the most popular emergency

antiepileptic

Importance of being in a safe location and position when a seizure begins

Potential uses - EpilepsyAssess severity of

seizure○ Automatically contact

emergency services if over a certain severity level [check-in sys]

Track quantity of seizures, pre-seizure states, and potential triggering factors○ Would allow

elimination of triggering factors

○ [life-tracking software; diet, etc info; find trigs]

Emotional stress is implicated in 30-66% of seizures reported by epileptics

Potential uses - stroke

Advance detection of strokesEarly detection massively mitigates damage caused by

strokes○ Administering tissue plasminogen activators within the first 3

hours will dissolve the stroke-inducing clot, immediately stopping the stroke Minimizes brain damage

Monitoring could be done on high-risk populations [geriat pops]

Tissue plasminogen activator – protein stucture [clot-breaker; admin alot kills stroke clot]

Potential uses – Mood-tracking Algorithms to detect mood from

EEG signals already exist Currently a bit weak, but ever-

improving [*SVN, algorithms] Use in bipolar disorder,

depression Self-report method already used

○ NIMH Life Chart○ Adjective Mood Scale○ Etc.

Used in:○ Diagnosis [always low=depr; high pers=BP]

○ Symptom management Insight, prep, meds

Automating mood tracking would increase adherence, and remove the potential confounding factors inherent in a self-rating system

Mood-tracking graph from Introspect software demo [*Impr]

Potential uses – Neurofeedback As discussed earlier, potentially a useful treatment for a

variety of mental disordersEspecially ADHD

Increase opportunity for neurofeedbackHuge hurdles to using the therapy: number of required

sessions and costPortable device could allow patients to do neurofeedback daily

on their own, incr rate of progress [& cost] Could allow incorporation of neurofeedback into daily life

Small alarms to inform user of problematic thought patterns, excessive anxiety states, wandering attention, etc. [Caveat: effective?]

Neurofeedback when walking or waiting○ Possibly more persistent benefits if done as a daily exercise?

Potential uses - sleep Will allow daily tracking of

sleep quantity and qualitySleep quality detection

algorithms are at a relatively high level

Already similar commercial products○ Sleeptracker, Zeo Personal

Sleep Coach, etc. Advantage of Introspect: it

will integrate it with other functions○ Search for relationships

between sleep quality and levels of attention, mood, anxiety, etc.;

Zeo Personal Sleep Coach

Potential uses - sleepCould aid in diagnosis of:

○ Sleep disorders○ Mental disorders that

involve sleep disruptionsWill also include

neurofeedback application to help chronic insomnia sufferers train their thinking to help induce sleep○ However, more evidence

required Chronic insomnia

Potential uses - research The list of mental phenomena

that could be examined by a portable EEG device is endless:Formation of autobiographical

memories – this is impossible in the lab

Minute-to-minute fluctuations in mood in those with mental and neurological disorders, and in the general population

Naturalistic social interaction, outside the artificial constraints inherent in social research in the lab

Average level of activation of particular areas of the brain on a day-to-day basis

etc.

Autobiographical memory formation could easily be studied in this circumstance with a

portable EEG device

Potential uses - research It could also determine the external validity of

laboratory and clinic-based EEG researchCombined with studies correlating EEG with fMRI,

MEG and PET activity, it could determine the external validity of the entire field of neuroimaging

A combined fMRI-EEG device

9) In conclusion... EEG’s future value lies in its portability

As its price drops, MEG likely to slowly replace EEG for all uses requiring no portability

Many potential uses for portable EEG Advance seizure and stroke detection Tracking of mood disorders Neurofeedback that can be done on a daily basis and incorporated into

day-to-day life Tracking of sleep quality and quantity that can be used in conjunction

with other measures for diagnostic purposes, and for the treatment of sleep disorders

Diagnosis of multiple mental disorders Research

EEG technology in the process of being commercialized Multiple consumer EEG devices already released – IE Emotiv, Neurosky

Thus, the time is right for the release of a portable consumer EEG device Currently in development by Personal Neuro Devices, under the

working title Introspect

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