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Interface to the brain
For the past eighteen months Paul Gnanayutham (De Montfort University), Chris
Bloor (University of Sunderland) and Eamon Doherty (Fairleigh Dickinson University)
have been working on new applications for brain computer interface devices.
Gaining control
Cyberlink can be used as a control technology that combines eye movement, eye blink, facial muscle and brain wave bio-potentials detected at the user's forehead to generate a mouse input that can be used for communicating. Cyberlink uses the forehead as a non-invasive site for convenience and also because it has a rich variety of bio-potentials. The signals for communicating are obtained by attaching probes on the forehead of the patients. Three silver/silver chloride contact electrodes (i.e. non-invasive) are placed on a headband to pick up EEG (brain wave), EMG (muscle movement wave) and EOG (eyeball movement) signals when applied on the forehead. These are then fed into an amplifier box and then to the mouse port, so the computer just sees the device as a mouse, which is used to control the cursor. Cyberlink comes with various games for recreation and training which are used to introduce Cyberlink to new users. However, there is one particular program of interest in the study, and that is the CAT part of the Cyberlink program. This application allows a user to access a computer desktop via the Cyberlink, using EOG, EMG and EEG to move around the desktop and open files and applications by blinking or other signals from the cyberlink. CAT can be configured according to he needs of individual users. The team in all the applications described in this article used CAT. Doherty and Bloor used the Cyberlink to communicate with brain-injured, non-verbal persons in the United States. Previously any communication would have been impossible with this group. The special users were also able to write simple words when prompted using the soft keyboard and Cyberlink. In the UK the University of Sunderland has been carrying out extensive research in the area of brain-body interface devices as a means of communication for brain-injured persons, who for many years were written off as vegetative patients. Now, some groups of brain-injured people are able to communicate using the brain body interface devices, although there is still more research to be done in this area. A taste of things to come
In the last two years Gnanayutham, Doherty and Bloor have been working on further research into diverse areas. This article deals with some of this new research, although many of the ideas still need extensive testing on users with special needs. Robots have been part of science fiction for many years, although some users with special needs already use robots for simple household chores. However, the brain-injured group has not harnessed this technology. The team has therefore been working to help a brain-injured user perform simple tasks using a robotic arm. A paper, presented at ICCIT New Jersey last year, explained how a robotic arm can be interfaced with a Cyberlink to perform simple tasks for brain-injured people, using a computer with one serial port for the Cyberlink and a parallel port for the interface to the robotic arm. Robotics aid movement
A Visual Basic program displayed six paths for controlling the robotic arm. The paths ended up in one of the functions of: arm up, arm down, arm left, arm right, open claw and close claw. When one of these six functions was triggered, the program drove a motor to perform the operation requested by the user, and the robotic arm was able to move left, right up, down and use claws to pick up a small object. This showed that in future brain-injured people could use robotics to do some basic tasks such as picking up a small object and moving it closer to the Cyberlink user. Gnanayutham took this technology to India, where the brain computer technology was tried using simple Visual Basic interfaces which allowed the users to communicate by using simple phrases and access applications such as the internet. The interfaces were translated to the local language and included simple phrases such as 'Thank you', 'Yes', 'No', 'I am hungry' and so on. The users were able to go to the internet site and access the sites set as default by their carers. Using the internet worked as long as the browser refreshed periodically without any user intervention. Sites that could be viewed using the interface were news and sports, which gave the users some recreation. The participants in India were a mixed sample aged from eight to 70 years. The older participants had Parkinson's disease, the after-effects of strokes or had become non-verbal after various illnesses. They were able to use a simple Visual Basic Yes/No interface to communicate with their families for the first time in many months. The brain-body interface was also tested at Mother Theresa's Institute for children with cerebral palsy. Out of 30 children tested, 12 were able to use the brain-body interface via the Visual Basic interfaces to communicate with their carers. The other children couldn't communicate because they were unable to comprehend the text on the Visual Basic interface. Valuable lessons
The main lesson learnt in India was that it is impossible to create one interface and expect it to be used for every participant with traumatic brain injury. Every person has a slightly different version of disability, therefore any program we create has to cater for individual needs. Cyberlink was the best choice of brain computer interface for this research since it used a variety of signals to communicate. There is still a lot of research being done at the University of Sunderland in this area and the team is grateful to the following Indian Institutes for their help and encouragement Vimhams, AIMS and Missionaries of Charities. Posted: 5 March, 2002
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