Classification of sphygmomanometers and basic construction

Mercury sphygmomanometer. There are two types of sphygmomanometers: desktop and vertical. The desktop mercury sphygmomanometer is well constructed, sturdy and reliable; the vertical sphygmomanometer can be adjusted to any height because its results are reliable and most used. However, the vertical sphygmomanometer is slightly larger and more difficult to carry, and there is a risk of mercury leakage. The principle of blood pressure measurement is the auscultation method, which consists of three main parts: the air capsule, the cuff, and the manometry group. The rubber capsule of the sphygmomanometer cuff is connected to the balloon and manometer, respectively, and the three form a gas-tight tube system. There are two types of manometers: mercury column type and spring type.

Electronic sphygmomanometer. According to the measurement, a part can be subdivided into upper arm type, wrist type, finger type, manual type, automatic type, etc. The advantages of electronic sphygmomanometers are ease of operation, intuitive readings, and automatic with only a toggle switch for measurement, making them suitable for home use. However, electronic sphygmomanometers also have the disadvantage of large errors, and they also require frequent calibration to a standard mercury column sphygmomanometer. The electronic sphygmomanometer principle has the auscultation method (also known as the Koch sound method) or the oscillation method (also known as the oscillation method). Mainly by the air pressure sensor, pressurized micro air pump, electronically controlled exhaust valve, the

Barometer type sphygmomanometer. It is also known clinically as the non-liquid sphygmomanometer and the spring-loaded sphygmomanometer. Using a pneumatic pump to operate the pressure measurement is small and portable, but as the number of applications increases, the accuracy of the results is affected by spring-like changes, so the standard mercury column sphygmomanometer needs to be calibrated periodically and is rarely used clinically.