Technology used: MWD technology (measured at reduced pressure)
Major components used: rapid pressure air pump, electronic quick exhaust valve, mechanical constant speed exhaust valve, pneumatic pressure sensor
Measurement features: rapid pressurization to a certain pressure value, venting at a rate of 2 to 7 mmHg/s through a mechanical constant speed vent valve, and blood pressure measurement during this deflation.
Feature 1: Use two exhaust valves ------ electronic quick exhaust valve, mechanical constant speed exhaust valve;
Feature 2: Initial pressurization pressure is usually set at about 200mmHg. The emphasis on pressurization speed is fast, usually within 10 seconds to reach the set pressure;
Feature 3: Immediately after the pressurization stops, the bleed air speed exceeds 7 mmHg/s. After a few seconds, the air release rate is approximately 2-7 mmHg/s. This generation of products will generally increase the initial pressurization pressure due to the instability (principle defects) of the mechanical constant-rate exhaust valve. For example, most domestic sphygmomanometers have their initial pressurization pressure mostly set at 190~200 mm. Hg, to a certain extent, can overcome the problem of measurement instability caused by the deflation velocity at the time of just stopping the pressurization.
The drawback is that the user's arm (or wrist) has a significant sense of pressure. At the same time, the measurement results are sometimes unstable due to the instability of the mechanical constant speed exhaust valve.
The second disadvantage of the mechanical fixed speed exhaust valve is that its exhaust speed is usually set according to the middle-thickness arm, while the actual user's arm is thick or thin, which affects the measurement accuracy.
The third drawback of the mechanical fixed-rate exhaust valve is that the rubber in it begins to age roughly six months to a year, and the exhaust speed set by the manufacturer is affected, eventually affecting the measurement accuracy.
The fourth disadvantage of the mechanical fixed-rate exhaust valve is that, even for the same measurement on the same subject, the exhaust velocity is high when the pressure is high, and the exhaust velocity is slow when the pressure is low. This will directly affect the accuracy of blood pressure measurement.
This generation of sphygmomanometer technology, the Japanese manufacturer, mostly stopped using it more than ten years ago. However, some domestic manufacturers who purchase electronic sphygmomanometer solutions are mostly in the first generation. And all solution providers only have this generation of technology solutions.