Good day, today I will discuss the principle of electronic sphygmomanometer.
Principle of electronic sphygmomanometers
Indirect blood pressure measurement methods are divided into auscultation method and oscillometric method.
The auscultation method has its inherent shortcomings: First, whether the diastolic blood pressure corresponds to the fourth phase or the fifth phase has always been disputed, and the discrimination error caused by this is very large. The second is to judge the systolic and diastolic blood pressure by listening to Korotkoff’s voice. The readings are affected by a series of factors such as the doctor’s mood, hearing, environmental noise, and subject’s nervousness. Subjective errors are easy to introduce and difficult to standardize.
Although the electronic sphygmomanometer made according to the principle of auscultation has realized automatic detection, it has not completely solved its inherent shortcomings such as large error, poor repeatability, and easy noise interference.
Most sphygmomanometers and automatic electronic sphygmomanometers use the oscillometric method to measure blood pressure indirectly. The oscillometric method determines blood pressure by establishing the relationship between systolic, diastolic, average pressure, and cuff pressure shock waves.
Because the pulse pressure oscillation wave has a relatively stable correlation with blood pressure, the blood pressure measured by the principle of the oscilloscope is more accurate than the auscultation method in the application of self-measurement of blood pressure at home. Moreover, when using the oscillometric method to measure blood pressure, there is no pickup device in the cuff, which is easy to operate and has strong anti-interference ability against external noise. It can also measure the average pressure at the same time.
It must be pointed out that from the point of view of measurement principle, the two indirect measurement methods do not have the problem of which is more accurate.
Well, today’s knowledge about the principle of electronic sphygmomanometers is introduced here. Next time I will continue to talk about the product structure of the blood pressure monitor