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BCI, Brain Computer Interfacing, what is it?

bci

INTRODUCTION

A brain-computer interface, sometimes called a direct neural interface or a brain machine interface, is a direct communication pathway between a human or animal brain(or brain cell culture) and an external device. In one BCIs, computers either accept commands from the brain or send signals to it but not both. Two way BCIs will allow brains and external devices to exchange information in both directions but have yet to be successfully implanted in animals or humans. Brain-Computer interface is a staple of science fiction writing. In its earliest incarnations no mechanism was thought necessary, as the technology seemed so far fetched that no explanation was likely. As more became known about the brain however, the possibility has become more real and the science fiction more technically sophisticated. Recently, the cyberpunk movement has adopted the idea of 'jacking in', sliding 'biosoft' chips into slots implanted in the skull(Gibson,W.1984).Although such biosofts are still science fiction, there have been several recent steps toward interfacing the brain and computers. In this definition, the word brain means the brain or nervous system of an organic life form rather than the mind. Computer means any processing or computational device, from simple circuits to silicon chips (including hypothetical future technologies like quantum computing). Research on BCIs has been going on for more than 30 years but from the mid 1990’s there has been dramatic increase working experimental implants. The common thread throughout the research is the remarkable cortical-plasticity of the brain, which often adapts to BCIs treating prostheses controlled by implants and natural limbs. With recent advances in technology and knowledge, pioneering researches could now conceivably attempt to produce BCIs that augment human functions rather than simply restoring them, previously only the realm of science fiction.


Brain Computer Interface


         What is a Brain Computer Interface? As mentioned in the preface a BCI represents a direct interface between the brain and a computer or any other system. BCI is a broad concept and comprehends any communication between the brain and a machine in both directions: effectively opening a completely new communication channel without the use of any peripheral nervous system or muscles.
            In principle this communication is thought to be two way. But present day BCI is mainly focusing on communication from the brain to the computer. To communicate in the other direction, inputting information in to the brain, more thorough knowledge is required concerning the functioning of the brain. Certain systems like implantable hearing-devices that convert sound waves to electrical signal which in turn directly stimulate the hearing organ already exist today. These are the first steps. The brain on the other hand is on a whole other complexity level compared to the workings of the inner ear.
From here on the focus is on communication directly from the brain to the computer. Most commonly the electrical activity (fields) generated by the neurons is measured, this measuring technique is known as EEG (Electroencephalography). An EEG-based BCI system measures specific features of the EEG-activity and uses these as control signals.
Over the past 15 years the field of BCI has seen a rapidly increasing development rate and obtained the interest of many research groups all over the world. Currently in BCI-research the main focus is on people with severe motor disabilities. This target group has little (other) means of communication and would be greatly assisted by a system that would allow control by merely thinking.







Medical Rehabilitation Uses

Worldwide, stroke is one of the leading causes of severe disabilities. Each year, there are around fifteen million new stroke cases across the world. Although more than two third stroke patients get satisfactory recovery after emergency treatment, medication and rehabilitation, the rest of stroke survivors have to undergo a long-term rehabilitation including physio and occupational therapies. For these stroke patients, upper limb weakness and loss of hand function are among the most devastating types of disabilities, which affect their daily lives. Although physiotherapy and occupational therapy are the most common treatments for those patients, the outcome of these treatments is limited by: (i) difficulty in improving the function of the plegic hand, (ii) difficulty in delivering intensive repetitions to patients with plegic hands for neuroplastic change and functional improvements, (iii) lack of motivation to sustain interest in the repetitive exercises, especially when patients go back home, and (iv) lack of immediate biofeedback.
         BCI used to teach patient how to move muscles to which the brain has forgotten how to control.

Communication ( Brain Gate )
Dummy unit illustrating the design of a Brain Gate interface Brain Gate is a brain implant system developed by the bio-tech company Cyberkinetics in 2003 in conjunction with the Department of Neuroscience at Brown University. The device was designed to help those who have lost control of their limbs, or other bodily functions, such as patients with amyotrophic lateral sclerosis (ALS) or spinal cord injury. The computer chip, which is implanted into the brain, monitors brain activity in the patient and converts the intention of the user into computer commands. Currently the chip uses 100 hair-thin electrodes that sense the electromagnetic signature of neurons firing in specific areas of the brain, for example, the area that controls arm movement. The activities are translated into electrically charged signals and are then sent and decoded using a program, which can move either a robotic arm or a computer cursor.


Gaming
Recently research into Brain-Computer Interfacing (BCI) applications for healthy users, such as games, has been initiated. But why would a healthy person use a still-unproven technology such as BCI for game interaction? BCI provides a combination of information and features that no other input modality can offer.
BCI types
·         Invasive BCI : Invasive Brain Computer Interface devices are those implanted directly into the brain and have the highest quality signals. These devices are used to provide functionality to paralyzed people. Invasive BCIs are also used to restore vision by connecting the brain with external cameras and to restore the use of limbs by using brain controlled robotic arms and legs. As they rest in the grey matter, invasive devices produce the highest quality signals of BCI devices but are prone to scar-tissue build-up, causing the signal to become weaker or even lost as the body reacts to a foreign object in the brain.
·         Non-Invasive BCI : Non invasive brain computer interface has the least signal clarity when it comes to communicating with the brain (skull distorts signal) but it is considered to be very safest when compared to other types. This type of device has been found to be successful in giving a patient the ability to move muscle implants and restore partial movement. Non-Invasive technique is one in which medical scanning devices or sensors are mounted on caps or headbands read brain signals. This approach is less intrusive but also read signals less effectively because electrodes cannot be placed directly on the desired part of the brain. One of the most popular devices under this category is the EEG or electroencephalography capable of providing a fine temporal resolution. It is easy to use, cheap and portable.
·         Partially Invasive BCI : Partially invasive BCI devices are implanted inside the skull but rest outside the brain rather than within the grey matter. Signal strength using this type of BCI is bit weaker when it compares to Invasive BCI. They produce better resolution signals than non-invasive BCIs. Partially invasive BCIs have less risk of scar tissue formation when compared to Invasive BCI. Electrocorticography (ECoG) uses the same technology as non-invasive electroencephalography, but the electrodes are embedded in a thin plastic pad that is placed above the cortex, beneath the dura mater. ECoG technologies were first trade-in humans in 2004 by Eric Leuthardt and Daniel Moran from Washington University in St Louis. In a later trial, the researchers enabled a teenage boy to play Space Invaders using his ECoG implant. This research indicates that it is difficult to produce kinematics BCI devices with more than one dimension of control using ECoG. Light Reactive Imaging BCI devices are still in the realm of theory. These would involve implanting laser inside the skull. The laser would be trained on a single neuron and the neuron’s reflectance measured by a separate sensor. When neuron fires, the laser light pattern and wavelengths it reflects would change slightly. This would allow researchers to monitor single neurons but require less contact with tissue and reduce the risk of scar-tissue build up.

Ethical Considerations
The use of BCIs is still rather controversial. One ethical problem is whether it is permissible to use BCIs to treat patients when their informed consent cannot be obtained. This is only an issue with people who are completely unable to communicate (like those with total locked-in syndrome). There are several ways to address the problem. Most patients who cannot communicate probably have family members acting as legal guardians, and the doctors can inform them about the procedure and obtain their informed consent because they are responsible for the patient. In this way, the guardian has established a legal contract with the doctor. If a patient does not have any legal guardian, then the question remains. Should doctors refuse to treat a person who is unable to legally agree to surgery, or should they treat the person with the 9 aim of simply trying to improve the person's life? This problem is encompassed by the larger question of whether it is ethical to perform BCI surgery at all. This question can be viewed through two lenses: is it ethical to intentionally violate a person's body, even for therapeutic reasons? Or, is it unethical to use BCIs at all because by doing so we are “playing God?” Consequentialism is an ethical theory that it is moral to act in ways that produce good outcomes and avoid bad ones. The Principle of Utility states that actions are ethical which create the most happiness or pleasure for the most people and the least unhappiness or pain for the most people after considering everyone's perspective. According to this principle, treatment with BCIs is moral because it aims to improve the lives of people who have been disabled. The ACM Code of Ethics and Professional Conduct can also be used to address the ethical issues with therapeutic BCIs. Guideline 2.5 is “Give comprehensive and thorough evaluations of computer systems and their impacts, including analysis of possible risks.” This is exactly what a doctor must do when informing a patient about BCI treatment. As long as the doctor obtains a patient's informed consent, they are acting ethically and professionally in accordance with the ACM Code of Ethics. Therapy is just one aspect of the use of BCIs. The technology has made great strides in the past 20 years, with some devices, like the Intendix, already available to the public. In the future, therapeutic BCIs will become more and more prevalent as people realize that it may be possible for them to restore lost capability.


CONCLUSION

     Brain-Computer Interface (BCI) is a method of communication based on voluntary neural activity generated by the brain and independent of its normal output pathways of peripheral nerves and muscles. The neural activity used in BCI can be recorded using invasive or Noninvasive techniques. We can say as detection techniques and experimental designs improve, the BCI will improve as well and would provide wealth alternatives for individuals to Interact with their environment.


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