Patent ID: 8060172

Claim:
An in-vivo information measurement apparatus comprising: an insertion part for insertion into a body cavity; a tubular cover member disposed at the outermost periphery of the insertion part; a plurality of transparent window portions disposed with gaps therebetween on the cover member; a light projection unit, provided at a tip of the insertion part, that irradiates an examination site inside the body cavity via the window portion with intensity-modulated light intensity modulated at a first frequency; a light receiving unit, provided at the tip of the insertion part, that receives return light from the examination site via the window portion at a different position from the light projection unit; an optical detector that detects return light from the examination site received at the light receiving unit; an in-vivo information calculation unit that calculates in-vivo information for the examination site based on a phase shift between a modulated detection signal, formed by modulating a detection signal from the optical detector at a second frequency, and a reference signal having a difference frequency equal to the difference between the first frequency and the second frequency; and moving mechanism that moves at least one of the light projection unit and the light receiving unit in a disposition direction of the plurality of transparent window portions.