Improved virtual keyboard design for P300-based brain-computer interface

Amyotrophic lateral sclerosis (ALS), brainstem stroke, brain or spinal cord injury, cerebral palsy, muscular dystrophies, multiple sclerosis, and numerous other diseases impair the neural pathways that control muscles or impair the muscles themselves. Those most severely affected may lose all volunt...

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Main Author: Tay, Abel Ping Liang.
Other Authors: Vinod Achutavarrier Prasad
Format: Final Year Project
Language:English
Published: 2009
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Online Access:http://hdl.handle.net/10356/16939
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-169392023-03-03T20:34:17Z Improved virtual keyboard design for P300-based brain-computer interface Tay, Abel Ping Liang. Vinod Achutavarrier Prasad School of Computer Engineering A*STAR Institute for Infocomm Research (I2R) Forensics and Security Lab DRNTU::Engineering::Computer science and engineering::Computer applications::Life and medical sciences Amyotrophic lateral sclerosis (ALS), brainstem stroke, brain or spinal cord injury, cerebral palsy, muscular dystrophies, multiple sclerosis, and numerous other diseases impair the neural pathways that control muscles or impair the muscles themselves. Those most severely affected may lose all voluntary muscle control, including eye movements and respiration, and may be completely locked in to their bodies, unable to communicate in any way. The locked-in syndrome is a condition in which patients are fully conscious and aware of what is happening in their environment but are not able to communicate or move. Modern life-support technology can allow most individuals, even those who are locked-in, to live long lives, so that the personal, social, and economic burdens of their disabilities are prolonged and severe. Brain computer interfaces are used for patients who are locked-in, unable to use their limbs. It allows them to communicate with other people using solely brain signals. There is an existing brainy communicator interface that works by having the user focus on the alphabet that he wants to spell and P300 signals are read from the user’s scalp. A C# program written as part of the final year project has shown that the algorithm for word predictions as well as multiple button flashing simultaneously works and can be integrated into the P300 system to speed up word entry. The current program flashes all buttons randomly in a round for a few rounds, and then takes all values to determine which character has the highest probability. Algorithms for both word predictions and multiple letter flashing has been written and tested without integration. Both methods can be employed for testing of speed of entering letters and words into the system. However, having word predictions may increase the number of flashes as the number of buttons has been increased. Word predictions and multiple letter flashing are currently disabled in order to integrate with the P300 interface. Integration has been done incrementally and tested at every stage. Steps that help toward integration include spacing the characters with a bigger gap on the screen, changing non-flashing colours to blend into the background and making the flashing character as contrasting as possible. Experiments have shown that the speed has been improved by more than 30%. This will reduce fatigue in the user and allow the user to key in more characters. However, the accuracy is lowered by about 7% on the new program. Bachelor of Engineering (Computer Engineering) 2009-05-29T02:11:43Z 2009-05-29T02:11:43Z 2009 2009 Final Year Project (FYP) http://hdl.handle.net/10356/16939 en Nanyang Technological University 46 p. application/pdf
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic DRNTU::Engineering::Computer science and engineering::Computer applications::Life and medical sciences
spellingShingle DRNTU::Engineering::Computer science and engineering::Computer applications::Life and medical sciences
Tay, Abel Ping Liang.
Improved virtual keyboard design for P300-based brain-computer interface
description Amyotrophic lateral sclerosis (ALS), brainstem stroke, brain or spinal cord injury, cerebral palsy, muscular dystrophies, multiple sclerosis, and numerous other diseases impair the neural pathways that control muscles or impair the muscles themselves. Those most severely affected may lose all voluntary muscle control, including eye movements and respiration, and may be completely locked in to their bodies, unable to communicate in any way. The locked-in syndrome is a condition in which patients are fully conscious and aware of what is happening in their environment but are not able to communicate or move. Modern life-support technology can allow most individuals, even those who are locked-in, to live long lives, so that the personal, social, and economic burdens of their disabilities are prolonged and severe. Brain computer interfaces are used for patients who are locked-in, unable to use their limbs. It allows them to communicate with other people using solely brain signals. There is an existing brainy communicator interface that works by having the user focus on the alphabet that he wants to spell and P300 signals are read from the user’s scalp. A C# program written as part of the final year project has shown that the algorithm for word predictions as well as multiple button flashing simultaneously works and can be integrated into the P300 system to speed up word entry. The current program flashes all buttons randomly in a round for a few rounds, and then takes all values to determine which character has the highest probability. Algorithms for both word predictions and multiple letter flashing has been written and tested without integration. Both methods can be employed for testing of speed of entering letters and words into the system. However, having word predictions may increase the number of flashes as the number of buttons has been increased. Word predictions and multiple letter flashing are currently disabled in order to integrate with the P300 interface. Integration has been done incrementally and tested at every stage. Steps that help toward integration include spacing the characters with a bigger gap on the screen, changing non-flashing colours to blend into the background and making the flashing character as contrasting as possible. Experiments have shown that the speed has been improved by more than 30%. This will reduce fatigue in the user and allow the user to key in more characters. However, the accuracy is lowered by about 7% on the new program.
author2 Vinod Achutavarrier Prasad
author_facet Vinod Achutavarrier Prasad
Tay, Abel Ping Liang.
format Final Year Project
author Tay, Abel Ping Liang.
author_sort Tay, Abel Ping Liang.
title Improved virtual keyboard design for P300-based brain-computer interface
title_short Improved virtual keyboard design for P300-based brain-computer interface
title_full Improved virtual keyboard design for P300-based brain-computer interface
title_fullStr Improved virtual keyboard design for P300-based brain-computer interface
title_full_unstemmed Improved virtual keyboard design for P300-based brain-computer interface
title_sort improved virtual keyboard design for p300-based brain-computer interface
publishDate 2009
url http://hdl.handle.net/10356/16939
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