Development of portable eeg for treatment & diagnosis of disorders
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Transcript of Development of portable eeg for treatment & diagnosis of disorders
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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