What's the Blood Pressure Monitor ?

Electronic sphygmomanometer is a kind of medical equipment which uses modern electronic technology and indirect blood pressure measurement principle to measure blood pressure.

The electronic sphygmomanometer can be divided into arm type, wrist type and watch type. Its technology has experienced the development of the first generation (mechanical constant speed exhaust valve), the second generation (electronic servo valve), the third generation (pressure synchronous measurement) and the fourth generation (integrated gas circuit).

It is usually composed of blocking cuff, sensor, air pump and measuring circuit. Electronic equipment for blood pressure measurement using oscillographic method, Kirschner method or similar non-invasive indirect blood pressure measurement principle.

The principle of electronic sphygmomanometer is oscillographic, which is accurate in principle. The clinical verification of electronic sphygmomanometer is based on auscultation and statistical methods. But this does not mean that auscultation with mercury manometer is more accurate than that of electronic sphygmomanometer. Of course, it is not necessarily correct to think that the result of electronic sphygmomanometer is more accurate than that of auscultation with mercury manometer.

As mercury is too destructive to the environment, it is recommended not to use mercury sphygmomanometer. The state also banned the use of mercury sphygmomanometer from legislation.

The mercury sphygmomanometer used by doctors in hospitals is only a tool for pressure measurement. The view that mercury sphygmomanometer is an accurate sphygmomanometer is one-sided, because the mercury sphygmomanometer is only a manometer, and the key point lies in the auscultation conducted by doctors through stethoscope. Mercury sphygmomanometers are generally prohibited in developed countries, and pressure gauges are used. However, due to the mechanical design principle of pressure gauges, they must be calibrated once every three months.

Nowadays, the electronic sphygmomanometer has realized automatic intelligent measurement. The measured data can be automatically transmitted to the health management platform through the network, and the generated health data report will be fed back to users. The measurement results are more accurate than the traditional electronic sphygmomanometer because of the advanced technology.

It is normal for individual subjects to have differences between electronic sphygmomanometer and auscultation.

The indirect blood pressure measurement methods include auscultation method and oscillometric method.

Auscultation has its inherent shortcomings: first, there has been a debate on whether the diastolic blood pressure corresponds to the fourth phase or the fifth phase, which leads to a large error of discrimination. The other is to judge systolic and diastolic blood pressure by listening to the Coriolis voice. The readings are affected by a series of factors such as doctors' mood, hearing, environmental noise, and the tension of the subjects. It is easy to introduce subjective errors and is difficult to standardize.

Although the electronic sphygmomanometer based on auscultation has realized automatic detection, it has not completely solved its inherent shortcomings, such as large error, poor repeatability and easy to be disturbed by noise.

Most blood pressure monitors and automatic electronic sphygmomanometers use oscillographic method to measure blood pressure indirectly. The relationship between systolic blood pressure, diastolic blood pressure, mean pressure and cuff pressure shock wave was established.

Because of the stable correlation between pulse pressure shock wave and blood pressure, the blood pressure measured by Oscillographic principle is more accurate than auscultation method in the practical application of home blood pressure measurement. In addition, there is no pick-up device in the sleeve when the oscillographic method is used to measure blood pressure. It is easy to operate and has strong ability to resist external noise interference. The average pressure can also be measured at the same time.

It must be pointed out that in terms of measurement principle, there is no more accurate problem between the two indirect measurement methods.