Optical sensor, method of measuring optical signal, and apparatus for estimating blood concentration of analyte

An apparatus for estimating a blood concentration, the apparatus comprising:

• a light source configured to emit light;
• a photodetector array comprising a plurality of photodetectors positioned at different distances from the light source, each photodetector being configured to detect an optical signal returning from an object irradiated by the light emitted by the light source, and to measure a light intensity of the detected optical signal;
• and
• a processor configured to determine a correlation coefficient between variables based on the measured light intensity, to determine a quality of the optical signal based on the determined correlation coefficient, and based on a determination that the quality of the optical signal is an acceptable level or higher, to estimate a blood concentration of an analyte based on the measured light intensity.

A method of measuring an optical signal, the method comprising:

• emitting, by a light source, light onto an object;
• detecting an optical signal returning from the object irradiated by the light emitted by the light source, and measuring a light intensity of the detected optical signal;
• determining a correlation coefficient between variables based on the measured light intensity;
• and
• determining a quality of the optical signal based on the determined correlation coefficient.