1. (1) http://www.hke.co.jp/products/dennosin/denindex.htm
2. (2) http://www.sensa.co.jp/jpn/japanese.html
3. (3) K. Itoh, Y. Sudoh, and T. Ifukube: “Eye Gaze Communication System for People with Severe Physical Disabilities”, Trans. of IEICE D-I, Vol. J83-D-I, No. 5, pp. 495-503 (2000-5) (in Japanese)
4. (4) R. Cipolla and A. Pentland (edited): “A Computer Vision for Human-Machine Interaction”, Cambridge University Press (1998)
5. (5) H. Nakai, M. Watanabe, Y. Miyake, K. Takada, K. Yamashita, H. Shimmori, and K. Ishihara: “Automatic Respiration Monitoring System by Time-Varying Image Analysis”, Trans. of IEICE D-II, Vol. J83-D-II, No. 1, pp. 280-288 (2000-1) (in Japanese)