Patent ID: 7551282

Claim:
A body fluid constituents measurement device which utilizes a test paper holding a coloring reagent which reacts to a predetermined constituent of body fluid, and optically measures a quantity of the predetermined constituent in the body fluid specimen by means of colorimetry, the body fluid constituents measurement device comprising: a light-emitting element configured to emit irradiating light to said test paper, a light-receiving element configured to receive reflected light from said test paper, a driving control unit configured to control driving of said light-emitting element, a temperature measurement unit configured to measure ambient temperature in the vicinity of said light-emitting element, and a determination unit configured to determine a first light emission condition for driving said light-emitting element prior to performing measurement of a quantity of the predetermined constituent based on the ambient temperature measured by said temperature measurement unit, wherein after said light-emitting element is driven for a predetermined period of time under said first light emission condition, the body fluid is provided to said test paper under a second light emission condition different from the first light emission condition, and the measurement of the quantity of the predetermined constituent of the body fluid is performed by detecting at said light-receiving element a reflected light intensity from the test paper where color change occurs according to the quantity of the predetermined constituent of the body fluid.