Brain-Computer Interfaces in Medicine
Jerry J. Shih
Department of Neurology, Mayo Clinic, Jacksonville, FL
Dean J. Krusienski
bDepartment of Electrical and Computer Engineering, Old
Dominion University, Norfolk, VA
Jonathan R. Wolpaw
laboratory of Neural Injury and Repair, Wadsworth Center,
New York State Department of Health and State University of New York, Albany
Abstract
Brain-computer interfaces (BCIs) accumulate mind signals,
analyze them, and translate them into commands transmitted to output devices
performing preferred movements. BCIs do not use ordinary neuromuscular output
pathways. The predominant intention of BCI is to replace or repair beneficial
features to people disabled by using neuromuscular disorders such as
amyotrophic lateral sclerosis, cerebral palsy, stroke, or spinal cord damage.
From initial demonstrations of electroencephalography-based
totally spelling and single-neuron-based device manipulation, researchers have
long gone on to use electroencephalographic, intracortical,
electrocorticographic, and different mind alerts for increasingly more complex
management of cursors, robot arms, prostheses, wheelchairs, and other gadgets.
Brain-computer interfaces can also benefit rehabilitation after stroke and
other issues. In the future, they might increase the overall performance of
surgeons or different clinical specialists. Brain-pc interface technology is
the focal point of an unexpectedly developing research and development employer
that significantly thrilling scientists, engineers, clinicians, and the public.
Its destiny achievements will depend upon advances in 3 critical areas.
Brain-computer interfaces want signal-acquisition hardware
this is convenient, transportable, secure, and able to be characteristic in all
environments. Brain-computer interface systems wish to be tested in
lengthy-term research of real-international use by using humans with severe
disabilities, and effective and feasible fashions for their huge dissemination
should be implemented. Finally, the daily and moment-to-moment reliability of
BCI overall performance should be advanced in order that it procedures the
reliability of natural muscle-based totally feature. @ Read More daimondcreations jdesignfashion
Until lately, the dream of being capable of manipulate one's
environment thru mind had been inside the realm of science fiction. However,
the advance of generation has brought a brand new fact: Today, humans can use
the electric indicators from mind pastime to have interaction with, influence,
or trade their environments. The emerging area of mind-computer interface (BCI)
technology can also allow people unable to speak and/or use their limbs to yet
again communicate or perform assistive devices for on foot and manipulating
objects. Brain-laptop interface research is an area of high public attention.
Videos on YouTube in addition to news reports in the lay media indicate severe
curiosity and hobby in a field that with any luck in the future quickly will
dramatically enhance the lives of many disabled people affected by some of
extraordinary disease procedures.
This evaluation seeks to provide the overall medical network
with an creation to BCIs. We outline BCI and then overview a number of the
seminal discoveries on this hastily rising discipline, the mind indicators
utilized by BCIs, the essential additives of a BCI gadget, current BCI
structures, and the key problems now attractive researchers. Challenges are
inherent in translating any new generation to practical and useful medical
programs, and BCIs are no exception. We talk the ability makes use of and users
of BCI structures and deal with a number of the constraints and challenges
facing the sector. We also don't forget the advances that may be viable inside
the next numerous years. A particular presentation of the primary principles,
cutting-edge nation, and destiny potentialities of BCI generation become
recently published.1
What is a BCI?
A BCI is a pc-based totally system that acquires brain
alerts, analyzes them, and translates them into instructions which can be
relayed to an output device to carry out a favored movement. Thus, BCIs do not
use the mind's everyday output pathways of peripheral nerves and muscle
tissues. This definition strictly limits the term BCI to structures that degree
and use signals produced by means of the primary anxious system (CNS).
Thus, for instance, a voice-activated or muscle-activated
communique machine isn't a BCI. Furthermore, an electroencephalogram (EEG)
system on my own isn't a BCI because it handiest records mind indicators but
does now not generate an output that acts on the person's environment.
It is a misconception that BCIs are thoughts-reading devices.
Brain-laptop interfaces do no longer read minds in the feel of extracting data
from unsuspecting or unwilling customers however enable customers to behave on
the world by using the use of mind alerts in place of muscle tissues. The
person and the BCI paintings collectively. The consumer, frequently after a
duration of schooling, generates mind signals that encode intention, and the
BCI, additionally after training, decodes the indicators and translates them
into instructions to an output tool that accomplishes the consumer's intention.
Milestones in BCI Development
Can observable electric brain alerts be placed to paintings
as carriers of statistics in individual-pc communique or for the motive of
controlling devices together with prostheses? That became the query posed via
Vidal in 1973.2 His Brain-Computer Interface Project changed into an early
attempt to evaluate the feasibility of the use of neuronal alerts in someone-pc
communicate that enabled computer systems to be a prosthetic extension of the mind.
Although paintings with monkeys inside the overdue 1960s
showed that alerts from single cortical neurons can be used to govern a meter
needle,three systematic investigations with people honestly commenced inside
the Seventies. Initial progress in human BCI studies turned into sluggish and
restricted via pc capabilities and our own information of mind physiology.
By 1980, Elbert et al4 established that persons given
biofeedback sessions of gradual cortical potentials in EEG hobby can alternate
those potentials to govern the vertical actions of a rocket image travelling
throughout a tv screen.
In 1988, Farwell and Donchin5 showed how the P300
event-related capacity could be used to allow everyday volunteers to spell
phrases on a laptop screen. Since the 1950s, the mu and beta rhythms (ie,
sensorimotor rhythms) recorded over the sensorimotor cortex were recognized to
be associated with movement or movement imagery.
6 In the overdue 1970s, Kuhlman7 showed that the mu rhythm
may be stronger by EEG remarks schooling. Starting from this statistics, Wolpaw
et al8-10 educated volunteers to govern sensorimotor rhythm amplitudes and use
them to move a cursor on a pc screen as it should be in 1 or 2 dimensions. By
2006, a microelectrode array was implanted inside the primary motor cortex of a
younger man with complete tetraplegia after a C3-C4 cervical damage. Using the
indicators obtained from this electrode array, a BCI device enabled the
affected person to open simulated email, operate a television, open and near a
prosthetic hand, and perform rudimentary movements with a robot arm.11 In 2011,
Krusienski and Shih12 verified that indicators recorded without delay from the
cortical floor (electrocorticography [ECoG]) may be translated by means of a
BCI to allow someone to correctly spell phrases on a pc display. Brain-laptop
interface studies is developing at an exceptionally speedy price, as evidenced
by using the range of peer-reviewed publications on this subject over the last
10 years (Figure 1).
Brain-laptop interface articles inside the peer-reviewed
clinical literature. Over the beyond 15 years, BCI studies, which changed into
previously limited to 3 laboratories, has turn out to be an extremely energetic
and hastily developing clinical discipline. Most articles have regarded in the
closing 5 years. BCI = mind-computer interface.
Physiologic Signals Used By BCIs
In principle, any sort of brain sign can be used to
manipulate a BCI device. The most usually studied signals are the electrical
signals produced specially by means of neuronal postsynaptic membrane polarity
adjustments that arise due to activation of voltage-gated or ion-gated
channels. The scalp EEG, first described by using Hans Berger in 1929,14 is
essentially a degree of these alerts. Most of the early BCI work used
scalp-recorded EEG indicators, which have the advantages of being easy, safe,
and cheaper to accumulate. The essential disadvantage of scalp recordings is
that the electric signals are considerably attenuated in the method of passing
thru the dura, skull, and scalp.15 Thus, crucial records can be misplaced. The
problem is not surely theoretical: epileptologists have long recognised that
some seizures which are definitely identifiable throughout intracranial
recordings aren't visible on scalp EEG. Given this feasible difficulty, recent
BCI work has also explored approaches of recording intracranially.
Small intracortical microarrays just like the one implanted
within the formerly stated case of tetraplegia11 can be embedded in the cortex.
These intracortical microarray structures can document the movement potentials
of person neurons and the nearby area potentials (basically a micro-EEG)
produced by using a pretty limited population of nearby neurons and synapses.
The negative aspects of such implants are the degree of invasiveness, with the
want for craniotomy and neurosurgical implantation, the limited place of
recording, and the nonetheless unanswered question of the lengthy-time period
functional balance of the recording electrodes. In addition to scalp EEG and
intracortical BCIs, ECoG-primarily based BCIs use every other technique to
report mind alerts. These BCIs use alerts obtained by means of grid or strip
electrodes at the cortical surface12 or stereotactic depth macroelectrodes that
document intraparenchymally16 or from inside the ventricles.17 These electrode
arrays have the advantage of recording intracranially and might document from
large areas of the mind than intracortical microarrays. However, those
electrodes additionally need neurosurgical implantation, and the query of
long-term electrode signal recording stability is as yet unanswered. Each of
these strategies has its own strengths and weaknesses. Which ones are
first-class for which functions and which person populations remains to be
visible. As BCIs come into scientific use, the selection of the recording
technique is likely to depend in full-size measure on the needs of the
individual BCI consumer and the technological support and sources available
(Table).
TABLE
Brain Signal Recording Techniques to Control Brain-Computer
Interface Systems
The advance of useful neuroimaging strategies with excessive
spatiotemporal decision now affords capability new techniques for recording
mind signals to govern a BCI. Magnetoencephalography (MEG) measures specially
the magnetic fields generated by using electrical currents shifting alongside
pyramidal mobile axons. The mu rhythm as detected with the aid of MEG became
utilized by a sensorimotor BCI machine to manipulate a computer cursor.18
Modulation of the posterior alpha rhythm as recorded via MEG became felt to
supply satisfactory manage of a 2-dimensional BCI undertaking.19 Functional
magnetic resonance imaging (fMRI) and purposeful near-infrared imaging (fNIR)
degree the blood oxygenation of a cerebral place and correlate with neural
pastime.1 Lee et al20 proven that control of a robot arm handiest via the
character's concept procedures became viable the use of a real-time
fMRI-primarily based BCI. These BCI strategies are within the early phases of
studies and development. MEG and fMRI are at gift extraordinarily costly and
cumbersome, and fMRI and fNIR have noticeably slow response instances. Thus,
the potential price of those more moderen practical imaging strategies for BCI
functions remains uncertain (although fMRI could prove precious in finding
suitable places for implantations of microelectrode arrays).
Components of a BCI System
The reason of a BCI is to detect and quantify features of
mind signals that imply the consumer's intentions and to translate these
features in real time into device commands that accomplish the consumer's
rationale (Figure 2). To gain this, a BCI gadget includes four sequential
components22: (1) signal acquisition, (2) feature extraction, (three)
characteristic translation, and (4) tool output. These 4 components are
controlled by an working protocol that defines the onset and timing of
operation, the information of sign processing, the character of the device
commands, and the oversight of overall performance. An effective working
protocol permits a BCI device to be bendy and to serve the precise needs of
each user.
Components of a BCI device. Electrical alerts from mind
interest are detected by way of recording electrodes placed on the scalp, on
the cortical floor, or within the mind. The brain indicators are amplified and
digitized. Pertinent signal characteristics are extracted after which
translated into commands that manage an output tool, along with a spelling
application, a motorized wheelchair, or a prosthetic limb. Feedback from the
tool allows the consumer to alter the mind signals so one can keep effective
tool performance. BCI = brain-pc interface; ECoG = electrocorticography; EEG =
electroencephalography. @ Read More technologyiesbusiness fitforvogue
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