Blood Pressure Watch
1. The pulse wave waveform of the wrist is collected by the photoelectric sensor (PPG) to judge the blood pressure. This is the cheapest and least accurate solution.
2. It is expensive to measure by means of air pressure pump. It is expected that Huawei may adopt this method.
3. Photoelectric + ECG integrated algorithm, adding metal sheet to collect ECG signal to estimate blood pressure on the basis of photoelectric signal.
Neither method can completely replace the measurement of the sphygmomanometer, in other words, it is only a reference value. The data shows that there is a big error in the measurement data of smart watch bracelets on the market. The systolic (high pressure) error value was the smallest at 6.4 mmHg; the largest error was 19.5 mmHg. Diastolic blood pressure (low pressure) is similar, with the smallest error value of 5.7 mmHg and the largest reaching 12.4 mmHg. The medical standard is no more than 12.4 mmHg.