Non-Invasive BCI
1929
Hans Berger – Discovered the EEG Electroencephalograph –
Signal Reflecting the electrical field produced by trillions of individual synaptic connections in the cortex and subcortical structures of the brain
EEG
EEG
EEG
Niels Birbaumer – Trained severely paralyzed people to self-regulate
the slow cortical potentials in their EEG in such a way that these signals could be used as a binary signal to control a computer cursor (1990s)
Tests included writing characters with the cursor System users require training just as any person is
trained to use a keyboard or a computer
Those who depend
ALS
Amyotrophic Lateral sclerosis –Muscle weakness and atrophy throughout the body
caused by the degeneration of upper and lower motor neurons.
Individuals may ultimately lose ability to initiate and control all voluntary movement
For the most part, cognitive function is preserved Sensory nerves and the autonomic nervous system
are generally unaffected
ALS
BCI systems have the ability to allow a paralyzed, “locked-in” patient to communicate words, letters and simple commands to a computer interface that recognizes different outputs of EEG signals and translates them through use of assigned algorithms into a specific function or computing output that the user has the ability to control.
A complex mechanical BCI system would allow a user to control an external system possibly an artificial limb by creating an output of specific EEG frequency
P300 Speller
User observes 6x6 matrix where each cell contains a character or symbol
User receives stimuli that coordinate with a specific output
User learns to recognize certain stimuli that exist in relation to a specific output
System created successful feedback when tested among the ALS population
EEG Rhythms
For analyzing EEG signals, studies suggest that frequencies of 8-12 Hz (mu) and 13-28 Hz (Beta) are most sensible for human control
The form or magnitude of a voltage change evoked by a stereotyped stimulus is known as an evoked potential and can serve as a command
ie. The amplitude of the EEG in a particular frequency band, can be used to control movement of a cursor on a computer screen
Non-Invasive BCI
Forefront of human experimentation
Cost effective
No implantation
Susceptible to noise
Cranial barrier dampens signal
What about right now
Today, BCIs are already being incorporated into modern technologically dependent society As they were once thought to be strictly
a bridge between a neurologically
disconnected brain to an outside mechanism
of replacing neuromuscular function,
the commercial exploitations have already
begun as devices can now be purchased that
allow users to control an exterior system
and navigate and control a graphical
Interface using only EEG output signals
NeuroSky
Developers at NeuroSky created the Brainwave, a comprehensive non-invasive BCI that connects the user to iOS and Android platforms, and transfers all signal information through Bluetooth as opposed to radio.
The EEG outputs for this setup are controlled primarily by variations in brain-state. In order to achieve a specific level of EEG the user may be prompted to relax or improve focus, thus altering the specific output of brain energy and ultimately changing the level of expressed EEG signals
Emotiv
Devolped a BCI called the EPOC
16 sensors capture EEGs to the extent of which the system can return feedback to let the user know whether or not they blinked, or sneezed, or smiled
The device allows a user to connect to a computer, and perform all basic functions that they otherwise would control using a keyboard, but with the mind. That includes control of gaming platforms as well
Future
For the future, BCI technology seems very applicable in a wide variety of areas whether it be medically or commercially
The possibilities of how far the systems can go is virtually limitless
Control of subvocalization and more advanced EEG processing could lead to telepathic communication and active learning mechanisms
This all would bring up an unfeasible amount of ethical discomfort and confrontation
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