Abstract: A light emission unit that emits a laser beam to a region of a subject portion that includes a measurement-target portion; a photodetector that receives reflected light based on the laser beam and detects an intensity of the reflected light; a first lens that is disposed between the subject portion and the photodetector in a position where the reflected light from a specific region in the subject portion can form a focused image on the photodetector; and a measurement controller that, based on the intensity of the reflected light, measures a concentration of the substance in blood in the specific region as a concentration of the substance in blood in the measurement-target portion, and the light emission unit selectively emits a first laser beam that is absorbed by a first substance in blood, and a second laser beam that is absorbed by a second substance in blood.

Abstract: A light emission unit that condenses and emits a laser beam to a specific region in a subject portion, the specific region being present in skin located on the reverse side of a living body from a skin surface on a side of the living body facing a main surface of a base, a photodetector that, on the main surface-side of the base, receives signal light having lower light intensity than the laser beam in some wavelengths and detects an intensity thereof, a lens that is disposed in a position where a focused image of the signal light from a laser-beam condensing region can be formed on the photodetector, and a measurement controller that measures a concentration of a substance in blood based on the intensity of the signal light are provided.

Abstract: A control section as a tissue identification device includes: an absorbance ratio calculating section configured to calculate the ratio of an absorbance indicated by a transmitted portion of first inspection light transmitted through biological tissue to an absorbance indicated by a transmitted portion of second inspection light transmitted through the biological tissue; and an identification information generating section configured to generate identification information indicative of the type or state of the biological tissue by determining within which of a plurality of preset numerical ranges the ratio falls.

Abstract: A substance-in-blood concentration measurement device for measuring concentration of a substance in blood of a living body, including: a target placement unit on which the living body that includes a measurement target portion is placed; a light emission unit that irradiates the measurement target portion with a laser beam; a photodetector that receives reflected light from the measurement target portion and detects intensity of the reflected light; and a condenser lens disposed on an optical path of the reflected light between the measurement target portion and the photodetector. On the optical path from the measurement target portion to the photodetector, in a section from the target placement unit to the photodetector, the reflected light propagates through space, except where transmitted through the condenser lens, and the condenser lens forms an image of the reflected light on the photodetector.