The standard version of sphygmomanometer adopts oscillation method.

Select the time with the highest fluctuation as the reference point, and use this as a basis. Looking forward at the fluctuation point with a peak value of 0.45 is the systolic blood pressure, and looking back at the fluctuation point with a peak value of 0.75. The corresponding pressure at this point is the diastolic blood pressure, while the corresponding pressure at the highest fluctuation point is the average pressure. It is worth mentioning that the constants of 0.45 and 0.75 vary depending on the manufacturer and are determined based on the statistical results of clinical trials. The sphygmomanometer is a commonly used sphygmomanometer, and 80% of families with sphygmomanometer are using it. It is only advanced in electronic blood pressure measurement, but the measurement technology is not very good.

Due to the fluctuating and irregular blood pressure values, there may be a certain maximum value, so the calculated data cannot reflect the blood pressure value. Therefore, the dosage of blood pressure is also based on assumptions. Standardization of the first waveform; Secondly, the formulas and coefficients used to calculate blood pressure (0.45 and 0.75) are the same as those used by the subjects. Healthy people can generally approach this coefficient, while unhealthy people usually cannot, but only unhealthy people require more blood pressure monitoring. Based on extensive human experiments, statistical methods are used, which inevitably result in some population measurement errors, sometimes reaching tens of millimeters of mercury. According to statistics, the oscillographic method is only applicable to 70% of the population, with a significant error for the remaining 30% of the population. For the same person, sometimes it is accurate, sometimes it is a significant error.