A living body is irradiated with a first light beam having a first wavelength and a second light beam having a second wavelength which is different from the first wavelength. The first light beam and the second light beam, which have been reflected or transmitted from the living body, are converted into...http://www.google.com/patents/US20040267140?utm_source=gb-gplus-sharePatent US20040267140 - Method for reducing noise, and pulse photometer using the method
