Method and device for measuring oxyhemoglobin saturation of central vein

The invention relates to a measuring device and method for the oxyhemoglobin saturation of a central vein, the measuring device comprises a central vein catheter, a first wafer, a second wafer and a photoelectric device, the first wafer and the second wafer are arranged on the central vein catheter, the photoelectric device is used for collecting optical signals, and the first wafer and the second wafer are respectively used for emitting at least two paths of light rays with different wavelengths to blood to be measured; the signal processing circuit is used for calculating the oxyhemoglobin saturation of the blood to be measured according to the first light intensity ratio and the second light intensity ratio; wherein in the light rays emitted by the first wafer and the second wafer, the value of the optical signal intensity corresponding to at least one path of light rays is smaller than the values of the optical signal intensity corresponding to other paths of light rays, so that at least one light intensi