1A high-performance MCU with a value of 5 seconds is adopted to significantly improve the operation speed. The second-generation LFC PLUS optical frequency digital conversion technology is adopted to greatly improve the measurement accuracy. 2Sound and light alarm, automatic alarm in the case of over-limit, alarm limit can be set according to needs. 3Intelligent power saving, automatic boot monitoring after finger inserted into the machine, automatic shutdown after finger removed 5s. 4When the pulse filling degree is 0.4%, the accuracy of oxygen saturation is 4%, and the accuracy of pulse rate is 2 BPM or 2%. 5Can be arbitrary rotation, small size and easy to carry, 0.95inch screen, dual color LED display.