1. Department of Orthoptics and Visual Sciences, Niigata University of Health and Welfare, Niigata 950-3198, Japan
2. Department of Health Informatics, Niigata University of Health and Welfare, Niigata 950-3198, Japan
3. Department of Clinical Engineering and Medical Technology, Niigata University of Health and Welfare, Niigata 950-3198, Japan