Authors:
Minoru Nakayama
1
;
Keiko Yamamoto
2
and
Fumio Kobayashi
2
Affiliations:
1
CRADLE (The Center for Research and Development of Educational Technolgy), Tokyo Institute of Technology, Japan
;
2
Aichi Medical University, Japan
Keyword(s):
Pupil size, Estimation, Support Vector Regression, Sleepiness test, Pupil Unrest Index.
Related
Ontology
Subjects/Areas/Topics:
Applications and Services
;
Biomedical Engineering
;
Biomedical Signal Processing
;
Computer Vision, Visualization and Computer Graphics
;
Informatics in Control, Automation and Robotics
;
Medical Image Detection, Acquisition, Analysis and Processing
;
Physiological Processes and Bio-Signal Modeling, Non-Linear Dynamics
;
Signal Processing, Sensors, Systems Modeling and Control
;
Time and Frequency Response
;
Time-Frequency Analysis
Abstract:
Pupillary response has been used for an index of sleepiness, but the validity of the index is not clear. In this paper, the influence of blinks on the Pupillary Unrest Index (PUI) and the Power Spectrum Density (PSD) for the frequency range 0.01 < f < 0.8H z, as indices of pupil’s instability during a sleepiness test, was examined. To estimate pupil size during blink, a procedure for collecting the clinical data was developed using Support Vector Regression (SVR). The values of PUI increased with experimental time, and the values and deviations of PUI for experimental observation were larger than the ones with SVR estimation. The blink time also increased with experimental time, and there were significant correlation relationships between the value of PUI and blink time. The mean PSD also correlated significantly with blink time. The relationship between pupillary indices and a subjective sleepiness index was not significant, as it was not in other previous works. These results provi
de evidence that pupillary indices were significantly affected by blink, and they did not reflect sleepiness correctly.
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