| 摘要 |
PROBLEM TO BE SOLVED: To appropriately determine a light irradiation position and a light-receiving position according to the depth of a blood vessel from a skin surface in a measurement of a noninvasive blood component measurement.SOLUTION: A tentative measurement light-emitting element 52S' to become an illumination position of measurement light is selected at a same or substantially same (W±α) position as a distance W, and a tentative measurement light-receiving element 52m' to become a light-receiving position, and a tentative reference light-receiving element 54r' are selected along the orthogonal direction of a center line L, while gradually adding and spreading the distance W from a blood vessel site 7b subject to a measurement to an upper limit value. The tentative measurement light-emitting element 52S' is made to emit light. A transmittance as a ratio of photometric luminance at the tentative measurement light-receiving element 52m' to photometric luminance at the tentative reference light-receiving element 54r' is calculated as an index of the blood vessel depth D of the blood vessel site from the skin surface. A light-emitting element and a light-receiving element selected corresponding to the distance W as a minimum transmittance are determined as the light-emitting element and the light-receiving element for use in the measurement. |
