At present, the blood oxygen test of Apple Watch Ultra is only used for fitness and health. According to the official, the measurement results of the blood oxygen app are not used for medical purposes (including self-diagnosis or consultation with doctors), but only for general fitness and health purposes.
That is to say, if you take it as an observation means of fitness and health at ordinary times, just look at the approximate value of blood oxygen, which can't be used as medical diagnosis data.
It is understood that the pulse oximeter has two light-emitting diodes, facing the patient's part to be measured, usually the fingertip or earlobe. One diode emits a light beam with a wavelength of 660 nm, and the other diode emits a light beam with a wavelength of 905, 9 10 or 940 nm. The absorption rate of oxygenated hemoglobin at these two wavelengths is very different from that in the absence of oxygen. Using this characteristic, the oximeter can calculate the ratio of two hemoglobin.
Yan Cheng, the head of medical device license application consulting business of Beijing Hongcheng Consulting Co., Ltd., told the reporter of China Consumer News: "For the measured value of blood oxygen saturation, the value detected by home oximeter is more accurate than that of smart wearable devices. General household oximeters are registered through medical instruments, that is to say, they have medical device production licenses, that is to say, these products have passed clinical experiments. Smart watches and bracelets are electronic products that can be produced and sold without clinical trials and registration by relevant departments. "
The technical person in charge of a medical device company said that the blood oxygen monitoring technology has been relatively mature since the 1970s, and the technical threshold is low, but this does not mean that the blood oxygen monitoring technology of smart watches has reached the medical level. Moreover, wrist movement, skin temperature, fat thickness, blood vessels and other factors will affect the accuracy of blood oxygen monitoring of smart watches. Therefore, the monitoring accuracy of smart watches is theoretically not as high as that of medical oximeter measuring fingertips.