Medical electronic sphygmomanometer and mercury sphygmomanometer relationship problems
The mercury column sphygmomanometer is used Korotkoff means, electronic blood pressure monitor using the oscillometric method, Korotkoff means is through the doctor with a stethoscope to listen to the voice of blood flow in a vessel, oscillometric method is by measuring the blood flow to the vessel wall to produce vibration; although the measurement principle is different, but the the test results from the theory is the same. But in fact, Korotkoff means because each doctor listening to reflect a different speed, sometimes due to blood pressure readings in measurement immediately down and have bigger error. Therefore each physician measurements will produce error, and electronic sphygmomanometer eliminates the difference between person and person, the doctor often omit some error integral. For example: 128mmHg, 131mmHg, doctors are read into 130mmHg. Electronic blood pressure meter is measured and what value display what value, and users, at home when measuring is always low, go to a hospital volume on high blood pressure, which is known as the white hypertension. That is to say in front of the hospital doctor, will imperceptibly produced some degree of anxiety, tension and stress, resulting in elevated blood pressure, and in a more relaxed, the blood pressure is low, this is the true reflection of human blood pressure.
The above phenomena together, can give a person a kind of electronic sphygmomanometer and the doctors measured blood pressure value does not match, and think the electronic sphygmomanometer no impression. In fact, according to the regulations, in a production license before, electronic sphygmomanometer must undergo clinical trials.