Principle Of Arm-type Electronic Blood Pressure Monitor

Indirect blood pressure measurement methods are divided into auscultatory method and oscillometric method.
The auscultation method has its inherent shortcomings: first, there has been a debate on whether diastolic blood pressure corresponds to the fourth phase or the fifth phase, resulting in a large discrimination error. The second method is to identify systolic blood pressure and diastolic blood pressure by listening to Korotkoff sounds. The readings are affected by a series of factors such as the doctor's mood, hearing, environmental noise, and the subject's nervousness. It is easy to introduce subjective errors and is difficult to standardize.
Although the electronic sphygmomanometer made based on the principle of auscultation has achieved automatic detection, it has not completely solved its inherent shortcomings, namely, large errors, poor repeatability, and susceptibility to noise interference.
Most blood pressure monitors and automatic electronic sphygmomanometers use the oscillometric method to indirectly measure blood pressure. Oscillometric blood pressure measurement determines blood pressure by establishing the relationship between systolic blood pressure, diastolic blood pressure, mean blood pressure and cuff pressure shock wave.
Because the pulse pressure oscillation wave has a relatively stable correlation with blood pressure, in actual home self-measurement of blood pressure, the blood pressure results measured using the oscillometric principle are more accurate than the auscultation method. Moreover, when measuring blood pressure with the oscillometric method, there is no pickup device in the cuff, which is simple to operate, has strong ability to resist external noise interference, and can also measure the average pressure at the same time.