Optical measurement device

An optical measurement device configured to be inserted into an inside of a subject via an insertion portion of an endoscope radiating observation light for observing a target from a distal end of the insertion portion to be inserted into the inside of the subject to shoot the inside of the subject, and to measure optical characteristics of a living tissue in the subject, the optical measurement device comprising:

• a measurement light source unit that emits measurement light including at least part of a wavelength band of the observation light radiated by the endoscope;
• a measurement probe including
• an illumination fiber configured to radiate the measurement light emitted from the measurement light source unit to the living tissue, and
• a light-receiving fiber configured to receive return light of the measurement light reflected and/or scattered from the living tissue;
• a detection unit that detects the return light of the measurement light received by the light-receiving fiber;
• an illumination control unit that causes the measurement light source unit to execute alternately emission and stoppage of the measurement light within the time from the start to end of the measurement by the optical measurement device, and causes the measurement light source unit to emit the measurement light such that the emission time during which the measurement light source unit emits the measurement light is longer than the stoppage time during which the measurement light source unit stops the measurement light;
• and
• a computation unit that removes, from an intensity of return light of the measurement light detected by the detection unit, a detected intensity of return light of the observation light radiated by the endoscope device and reflected from the living tissue, wherein
• the computation unit computes a detected intensity I_C in which the detected intensity of return light of the observation light is removed from the detected intensity of return light of the measurement light by the following equation (1):
• I—C=I—ton−I—toff×(ton/toff) (1)
• where ton denotes the emission time, toff denotes the stoppage time, I_ton denotes the intensity detected by the detection unit during the emission time, and I_toff denotes the intensity detected by the detection unit during the stoppage time.