الگوی تحریک مبتنی‌بر شکلک -تصویری در هجی‌کنندة P-300 با صفحه شطرنجی

نوع مقاله: مقاله کامل پژوهشی

نویسندگان

1 دانشجوی کارشناسی ارشد، گروه مهندسی پزشکی، دانشکده مهندسی برق، دانشگاه علم و صنعت ایران، تهران

2 استادیار، گروه مهندسی پزشکی، دانشکده مهندسی برق، دانشگاه علم و صنعت ایران، تهران

10.22041/ijbme.2017.70699.1254

چکیده

هجی‌کنندة P300، یکی از رایج‌ترین واسط‌های مغز-کامپیوتر مبتنی‌بر ثبت الکتروانسفالوگرام است که توانایی‌های ارتباطی ساده‌ای را برای افراد دچار عارضه‌های شدید گفتاری یا حرکتی فراهم می‌کند، تا قادر باشند بهتر با محیط اطراف خود ارتباط برقرار کنند. استفاده از الگوی صفحة شطرنجی معرفی‌شده توسط Townsend و همکارانش [1]، به‌جای الگوی سطری-ستونی، یکی از موفق‌ترین الگوهای تحریک ارائه‌شده در مطالعات قبلی برای افزایش دقت هجی‌کننده بوده است. هدف روش پیشنهادی این مطالعه، که با عنوان الگوی شطرنجی با تحریک شکلک-تصویری نام‌گذاری شده است، بررسی اثر جایگزینی تحریک شکلک-تصویری در الگوی صفحة شطرنجی و مقایسة کارآیی آن با تحریک چشمک زدن کاراکترها است. در این مطالعه، چشمک زدن کاراکترها در الگوی شطرنجی را با نمایش یک شکلک-تصویری به‌جای کاراکتر‌ها جایگزین کردیم. برای ارزیابی و مقایسة کارایی الگوی پیشنهادی با الگوی شطرنجی، برای هر‌یک از دو الگو، هجی‌کننده روی داده‌های ثبت‌شده از ده فرد سالم در فاز برون خط، تعلیم داده شد و دقت هجی‌کننده در فاز برخط محاسبه شد. ارزیابی آزمون برخط نشان داد، میانگین دقت طبقه‌بندی هجی‌کننده با استفاده از الگوی پیشنهادی این مطالعه نسبت به الگوی شطرنجی، 14% بهبود یافته است. یافته‌های این مطالعه نشان می‌دهد که تحریک ناشی از نمایش شکلک-تصویری به‌جای چشمک زدن کاراکترها، نقش مؤثری در افزایش دقت طبقه‌بندی هجی‌کننده داشته است.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Using Emoji Stimuli for Checker-Board P300 Speller

نویسندگان [English]

  • Hesam Moradkhani 1
  • Vahid Shalchyan 2
1 MSc. Student, Electrical Engineering Faculty, Iran University of Science and Technology, Tehran, Iran
2 Assistant Professor, Electrical Engineering Faculty, Iran University of Science and Technology, Tehran, Iran
چکیده [English]

P300 Speller as a most commonly used brain–computer interface (BCI) has been able to provide simple communication capabilities for people with severe motor or speech disabilities in order to have a better interaction with the outer world over the past years. Checker-board paradigm introduced by Townsend et al. [1] is one of the most practical alternatives for row-column paradigm, enhancing the performance of the speller by preventing row-column induced errors. In this study, we investigated the effect of substituting presentation of an emoji stimulus instead of flashing the characters in the performance of a checker-board P-300 speller. The performance of the proposed paradigm was evaluated and compared to the traditional stimuli in checker-board paradigm in an online experiment over ten healthy subjects. For each paradigm, the recorded data from an offline session was used to calibrate the speller classifier; and consequently, the classification accuracy was calculated over online sessions. The proposed paradigm, showed 14% enhancement in classification accuracy with respect to the checker-board paradigm. The results of this study obviously showed that the stimuli obtained by presenting emoji instead of character flashing, effectively improved the speller classification accuracy.

کلیدواژه‌ها [English]

  • Brain-Computer Interface (BCI)
  • P300 Speller
  • Checker-Board Paradigm

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