A sphygmomanometer is a medical device used to measure human blood pressure. Its core function is to obtain systolic and diastolic blood pressure values by monitoring changes in intravascular pressure. According to measurement principles and technical differences, sphygmomanometers are mainly divided into three categories: mercury sphygmomanometer, electronic sphygmomanometer and ambulatory blood pressure monitor. The following four dimensions are selected from the working principle, type characteristics, usage methods and brands to expand the analysis:
First, the working principle
sphygmomanometer realizes measurement by sensing pressure fluctuations in the blood vessel. There are essential differences in the technical paths of different types of devices:
Mercury sphygmomanometer: Based on Pascal's law, the blood flow of the brachial artery is blocked by cuff pressure, and the change of the Korotkoff sound is captured by a stethoscope. When the cuff pressure is higher than the systolic blood pressure, the blood vessel is completely closed. When the pressure drops to the systolic blood pressure level, the blood breaks through the resistance of the blood vessel wall to form turbulence to produce the first Coriolis sound, which corresponds to the systolic blood pressure value. When the pressure continues to drop to the diastolic blood pressure level, the blood flow returns to a stable level, and the Coriolis sound disappears, corresponding to the diastolic blood pressure value.
Electronic sphygmomanometer: Using the oscilloscope method (oscillation method) technology, the pressure fluctuation in the cuff is captured by the pressure sensor. During the pressurization process, the pressure amplitude generated by the vibration of the blood vessel wall is mathematically related to the blood pressure value. The built-in algorithm of the device calculates the systolic and diastolic blood pressure by analyzing the peak amplitude and the characteristics of the front and rear fluctuations. Some high
Ambulatory Blood Pressure Monitor: Add data storage and timing measurement functions on the basis of oscilloscope method, and obtain blood pressure circadian rhythm data through 24-hour continuous monitoring to provide dynamic basis for hypertension diagnosis and treatment effect evaluation.