Patent ID: 8655426

Claim:
A device for measuring concentration of a constituent in blood comprising: a main body unit having dimensions capable of accommodating an inserted living body; an irradiation unit disposed on an inner surface of the main body unit, for irradiating light toward the living body when inserted, the light having a wavelength disposed in a light absorption band of the constituent in the blood; a light receiving unit for receiving light, which is reflected in the living body when inserted, or transmitted through the living body when inserted; and a concentration measurement unit for measuring the concentration of the constituent in the blood based on variation of light intensity of light received by the light receiving unit, the variation attributed to a pulse wave of the living body when inserted, wherein the main body unit has a V-shaped bottom, wherein the irradiation unit and the light receiving unit are disposed on the V-shaped bottom, and wherein the irradiation unit has an optical axis, which intersects with an optical axis of the light receiving unit, wherein the irradiation unit has a rounded irradiation surface, wherein the light receiving unit has a rounded reception surface, and wherein the rounded irradiation surface and the rounded reception surface are each capable of contacting the living body.