Tribute to Dr. Takuo Aoyagi, inventor of pulse oximetry. - Miyasaka, Katsuyuki; Shelley, Kirk; Takahashi, Shosuke; Kubota, Hironami; Ito, Kazumasa; Yoshiya, Ikuto; Yamanishi, Akio; Cooper, Jeffrey B.; Steward, David J.; Nishida, Hiroshi; Kiani, Joe; Ogino, Hirokazu; et al. (Journal of Anesthesia, 2021)