Naoki Kobayashi,Kenji Miyata,Masaru Yarita,Kazumasa Ito
申请号：
US11508995
公开号：
US08175669B2
申请日:
2006.08.24
申请国别(地区):
US
年份:
2012
代理人:
摘要：
In an apparatus for measuring an oxygen saturation in blood, a plurality of light emitters irradiate a living tissue with a plurality of light beams having different wavelengths. A light receiver receives the light beams reflected from or transmitted through the living tissue to generate pulse wave signals in accordance with pulsations of the blood in the living tissue. A separator separates each of the pulse wave signals into a plurality of amplitude signals each of which is associated with one frequency, thereby generating pairs of amplitude signals each of which is associated with one of a plurality of frequencies. A first processor calculates a ratio between the amplitude signals in each of the pairs of the amplitude signals. A selector selects one of the pairs of the amplitude signals. A second processor calculates the oxygen saturation from the ratio of the selected pair of the amplitude signals.
