What Is The Working Principle Of The Blood Pressure Monitor?

The instrument that measures blood pressure is called a sphygmomanometer. Sphygmomanometers can be divided into two types: direct and indirect. The working principles of the two sphygmomanometers are different. The direct type uses a pressure sensor to directly measure pressure changes; the indirect type uses a pressure sensor to directly measure the pressure change; The generation and disappearance of Korotkoff sounds are judged. The former can be tested continuously regardless of the artery or vein, while the latter can only measure the systolic and diastolic blood pressure of the artery. Indirect measurement instruments include mercury sphygmomanometer, random zero-point sphygmomanometer, spring-loaded sphygmomanometer, automatic electronic sphygmomanometer, intermittent long-term sphygmomanometer, skin arteriole sphygmomanometer, etc. These sphygmomanometers are designed according to different needs. For example, the random zero-point sphygmomanometer is used to overcome human errors such as visual observation and more accurately study blood pressure changes; the intermittent long-term sphygmomanometer is used to monitor blood pressure continuously for 24 hours Change; Skin arteriole blood pressure meter is designed for infants, infants, and newborns; due to the development of intelligence, the electronic blood pressure meter can automatically inflate the inflatable cuff and display the blood pressure value. The finger cuff type electronic sphygmomanometer only needs to wear a finger cuff on the finger to automatically measure blood pressure, which is more convenient. It should be noted that the blood pressure values measured by these automatic electronic sphygmomanometers may have a certain difference with the blood pressure values measured by the mercury column sphygmomanometer, which should be verified in advance and this difference should be remembered. In recent years, in accordance with the International Recommendation "Sphygmomanometer Revision Draft Regulations" put forward by the International Legal Metrology Organization, the scale of the sphygmomanometer has been changed from millimeter mercury (mmHg) to dry Pascal (kPa). 1kPa=7.5mmHg and the graduation value on the scale is 0.5kPa. At present, there are two scales on the sphygmomanometer, please pay attention when using them. Before the spring-loaded sphygmomanometer is activated, it should be checked first. Normally the sphygmomanometer that can be used normally should point to the zero position on the dial pointer. After pressurization, the response is flexible and can still return to the original zero position.