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Brain Computer Interface

Brain Computing Interface
A paralyzed man has become the first man to tweet using only his “direct
thought”. Yes, you read it right! Philip O’ Keefe suffers from Amyotrophic
Lateral Sclerosis or ALS, that has made him completely paralyzed, unable to
move his limbs. But how could such a person be able to tweet without the use of
his voice or keystrokes? Well, that was quite simple. He was able to turn his
thoughts directly to text using the Stentrode Brain Computer Interface (or BCI).
Now the question is, what exactly is this BCI? How did it help Philip to tweet
stuffs without any keystrokes or voice?
The Brain Computer Interface (BCI) is the linkage of the brain to computers
through scalp, subdural or intracortical electrodes. In simple terms, Brain
Computing Interface or BCI basically refers to the Neurobionics methodology
that enables communication based on the brain signals without any use of
peripheral nerves or muscles. In today’s world of advanced technology, BCI has
emerged as one of the most efficient methods that are being developed to enable
individuals with any sort of motor disorders (for example, amyotrophic lateral
sclerosis (ALS), brainstem stroke, cerebral palsy, and spinal cord injury) or
neuromuscular diseases (like Motor Neurone Disease (MND), Full Sliding Status
(TSD)) etc to communicate with their environment. In the last 15 years, the pace
of BCI has grown rapidly, emerging as an exciting advance in neuroscience and
BCIs are transforming the brain activities taken from the individual into
movement or writing through this application. For this purpose, it uses brain
signals to visualize the brain activities. BCI basically uses the EEG signals. After
obtaining the brain signals using a particular sensor modality like electrodes,
brain implants etc, the signals are amplified to levels suitable for electronic
processing (and they may also be subjected to filtering to remove electrical noise
or other undesirable signal characteristics, such as 60-Hz power line
interference). The signals are then digitized and transmitted to a computer. Then
feature extraction is performed for analysing the digital signals to distinguish
pertinent signal characteristics (i.e., signal features related to the person’s intent)
from extraneous content and representing them in a compact form suitable for
translation into output commands. These features should have strong correlations
with the user’s intent. The resulting signal features are then passed to the feature
translation algorithm, which converts the features into the appropriate commands
for the output device (i.e., commands that accomplish the user’s intent). Then
finally commands from the feature translation algorithm operate the external
device, providing functions such as letter selection, cursor control, robotic arm
operation, and so forth. The device operation provides feedback to the user, thus
closing the control loop.
In the case of Philip, the brain implant Stentrode, is using blood vessels as a
natural highway to the brain, which are laced with sensors that record activity.
These signals are then sent through a telemetry unit to a small computer taped to
the patient’s chest, which interprets what actions the individual wants to perform
on the nearby PC, such as texting, emailing and shopping online.
Many researchers throughout the world are developing BCI systems that a few
years ago were in the realm of science fiction. These systems use different brain
signals, recording methods, and signal-processing algorithms. A few people with
severe disabilities are already using a BCI for basic communication and control
in their daily lives. With better signal-acquisition hardware, clear clinical
validation, viable dissemination models, and, probably most important, increased
reliability, BCIs may become a major new communication and control
technology for people with disabilities—and possibly for the general population
1. News
2. Research Article (https://pubmed.ncbi.nlm.nih.gov/28446119/)
3. Research