Complex-Valued Wavelet Spectrum Analysis of Respiratory Conditions and Its Feasibility in the Detection of Low-Functional Respiration oleh Yoshikazu Nakajima, Takaaki Sugino, Masashi Kobayashi, Yasuhiro Nakashima, Yohei Wada, Yasuro Okumiya, Koji Yataka, Katsunori Suzuki, Toshihiro Kawase, Shinya Onogi, Kenichi Okubo