Oxygen saturation measuring sensor, and oxygen saturation measuring apparatus

An oxygen saturation measuring apparatus comprising:

• a sensor unit;
• and
• a main body, wherein
• the sensor unit comprises:
• a pad attachable to a human body;
• a plurality of light sources comprising a light source A and a light source B arranged on the pad adjacent to and spaced apart from one another, and that irradiate near-infrared light;
• a plurality of light receiving elements comprising a light receiving element A and a light receiving element B arranged on the pad adjacent to and spaced apart from one another and correspond one to one to the plurality of light sources with reference to a common center between 1) the light sources A and B, and 2) the light receiving elements A and B, and that receive transmitted light from the corresponding plurality of light sources, wherein distances between 1) the light source A and the light source B, 2) the light source B and the and the light receiving element B, and 3) the light receiving element A and the light receiving element B are the same;
• and
• a ROM unit that stores a reference value through measuring transmitted light using a phantom in advance, and
• the main body comprises:
• an arithmetic processing unit that calculates actual absorbance on the basis of a light receiving value and a reference value regarding an amount of receiving light stored by the ROM and computes an oxygen state of a living body to comply with the Beer-Lambert law while comparing the reference value.