Patent ID: 8406847

Claim:
A biological observation apparatus comprising: a sound wave radiating unit configured to radiate a sound wave into an object to be examined; a light radiating unit configured to radiate a first light having a first wavelength and a second light having a second wavelength into a portion of the object influenced by the sound wave; a detector configured to detect reflected light of the first light and reflected light of the second light; and a calculator configured to calculate characteristic information of the object based on the reflected light of the first light and the reflected light of the second light, wherein a first absorption characteristic of the first light and a second absorption characteristic of the second light have sensitivities that are lower with respect to a change of oxygen saturation in blood of the object, and the first absorption characteristic and the second absorption characteristic are substantially equal to each other with respect to blood having different oxygen saturations, and the calculator configured to calculate a difference value between intensity of the reflected light of the first light and an intensity of reflected light of the second light and to produce image data of the object based on the difference value, and wherein the calculator is configured to apply a frequency analysis to the difference value, thereby calculating a variation of an amount of frequency modulation at the portion of the object influenced by the sound wave, and to produce the image data of the object based on the amount of frequency modulation.