Irradiating the tooth 10 multiple wavelengths of light, such as absorption wavelength which is not affected by oxygen saturation of hemoglobin, by receiving the light transmitted through the teeth 10, the light from (dentin 14 and enamel 12) tooth I ask the blood flow and pulp cavity blood concentration excluding the impact of the scattering and absorption of. Furthermore, the light of such absorption wavelength which is not affected by oxygen saturation of hemoglobin, and, the transmitted light attenuation when irradiated to the teeth light non isosbestic wavelengths affected by oxygen saturation of hemoglobin, the Using the pulp cavity total amount of hemoglobin was determined by the method, to determine the oxygen saturation of the blood pulp cavity. Thus, without giving pain to the patient, and objective non-invasive, and can be quantitatively measured blood concentration of the pulp cavity (hemoglobin concentration), the oxygen saturation and blood flow volume in the light.ヘモグロビンの酸素飽和度の影響を受けない等吸収波長の複数の波長の光を歯10に照射し、歯10を透過した光を受光して、歯質(エナメル質12と象牙質14)による光の散乱・吸収の影響を除いた歯髄腔内血液濃度や血流量を求める。更に、ヘモグロビンの酸素飽和度の影響を受けない等吸収波長の光、及び、ヘモグロビンの酸素飽和度の影響を受ける非等吸収波長の光を歯に照射した時の透過光減衰度と、前記の方法で求めた歯髄腔内総ヘモグロビン量とを用いて、歯髄腔内血液の酸素飽和度を求める。これにより、患者に痛みを与えることなく、明所でも非侵襲的かつ客観的に、歯髄腔内の血液濃度(ヘモグロビン濃度)、血流量及び酸素飽和度を定量的に測定可能とする。
