1733, a priest named Hayes measured the blood pressure of animals for the first time. He inserted a 270-cm-long glass tube into a horse's carotid artery with a small metal tube at the end. At this time, blood immediately poured into the glass tube, reaching a height of 270cm. This means that the blood pressure in the horse's carotid artery can maintain a blood column height of 270cm, which will increase or decrease slightly due to the horse's heartbeat. Blood pressure will increase when the heart contracts (systolic pressure) and decrease when the heart relaxes (diastolic pressure).
1835, Julius Harrison invented a sphygmomanometer, which transmits the pulse to a narrow mercury column. When the pulse beats, mercury will jump up and down accordingly. For the first time, doctors can measure pulse and blood pressure without cutting off the artery. However, due to inconvenient use, rough production and inaccurate reading, other scientists improved it.
A sphygmomanometer measures blood pressure according to the height of a mercury column, and a barometer measures air pressure in the same way.
1860, Etienne Jules Marie (French scientist) developed the best sphygmomanometer at that time. It amplifies the pulse and records the pulse track on the roll paper. This sphygmomanometer can also be carried around. Horses use this sphygmomanometer to study the abnormal beating of the heart.
The sphygmomanometer used by doctors today was invented by Scipione Riva Roach (an Italian scientist) in 1896. It has an inflatable cuff to stop blood flow. The doctor listens to the pulse with a stethoscope and reads the blood pressure on the scale.
(Note: The earliest sphygmomanometer was used to measure the blood pressure of horses. After the changes of the times, sphygmomanometer has become more and more advanced. Many people have them at home, in order to understand their health. The measuring principle of sphygmomanometer can be divided into direct measurement and indirect measurement.
Direct measurement is also called invasive measurement, that is, the blood pressure measured after the catheter is inserted into the blood vessel through puncture. For example, it is necessary to monitor the invasive blood pressure of patients during the diagnosis and treatment of cardiac intervention. Blood pressure was measured directly by invasive method. Because of the different parts and methods, it can't fully reflect the blood pressure of human body.
Indirect measurement is also called noninvasive measurement, that is, after placing a catheter in a blood vessel without puncture, blood pressure is measured indirectly.
Indirect measurement method is divided into auscultation method and oscillometric method.
1, auscultation
The method of measuring human blood pressure by listening to Coriolis sound with a stethoscope is called auscultation, and the sphygmomanometer for measuring blood pressure by auscultation is called auscultation sphygmomanometer. Such as mercury sphygmomanometer, sphygmomanometer, etc. For more than 100 years, people have been exploring more reliable blood pressure measurement methods and instruments, but all failed, including oscillometric electronic sphygmomanometer. Therefore, domestic regular hospitals have to continue to use mercury sphygmomanometers, and developed countries in Europe and America have banned the use of mercury sphygmomanometers for environmental reasons, and their medical institutions use sphygmomanometers. In the face of previous failures, some people in the world call auscultation the gold standard for measuring blood pressure. Hundreds of years of historical facts have proved that auscultation is irreplaceable so far, and auscultation sphygmomanometer is a scientific and classic blood pressure measurement instrument.
Auscultation classification:
Auscultation sphygmomanometer can be divided into manual auscultation sphygmomanometer, semi-automatic auscultation sphygmomanometer and automatic auscultation sphygmomanometer. Manual auscultation sphygmomanometer is common with mercury sphygmomanometer and sphygmomanometer; Semi-automatic auscultation sphygmomanometer is helpful to read sphygmomanometer; Automatic auscultation sphygmomanometer has auscultation automatic sphygmomanometer.
1, artificial auscultation sphygmomanometer uses mercury as manometer. The measurer listens to the Coriolis sound of the original blood pressure through the stethoscope (from heavy to light, and then disappears or changes), and reads the systolic and diastolic blood pressure according to the Coriolis sound heard by the manometer; Although auscultation is the most accurate method to measure blood pressure at present, artificial auscultation is affected by the following factors: (1) training level; (2) listening; (3) attention; (4) The witness is not good at judgment. The reliability of blood pressure measurement depends entirely on the professional level, hearing, fatigue and working attitude of the measurer, and because blood pressure is instantaneous, unrepeatable and irrecomposable, it is as much as the measurer says. 2. Semi-automatic stethoscope sphygmomanometer uses an electronic probe similar to a stethoscope to listen to the Coriolis sound of blood pressure and amplify the volume through electronic technology. Everyone next to the sphygmomanometer can hear the Coriolis sound of blood pressure (all sounds are of the same weight), and read the systolic pressure and diastolic pressure according to the Coriolis sound. This method excludes the level of (1) training; (2) listening; (3) attention, etc. However, it is still affected by the difference of witness judgment. Although it can be used by more people to measure blood pressure, some people still find it troublesome to use. 3. The automatic stethoscope sphygmomanometer is to listen to the Coriolis sound of blood pressure with an electronic probe similar to a stethoscope, convert the Coriolis sound of blood pressure into a digital signal through modern digital technology, and finally display it on the monitor of the sphygmomanometer, thus realizing the automation of blood pressure measurement. This sphygmomanometer can also be divided into semi-automatic and full-automatic: manual inflation and automatic deflation are called semi-automatic; Automatic inflation and automatic deflation are called automatic. This sphygmomanometer has no influence on the training level, hearing, attention and witness difference in judgment, and everyone can use it to measure blood pressure accurately.
2. Oscillographic method
Oscillographic method, also known as oscillation method, is a relatively advanced electronic measurement method developed in the 1990s.
Its principle is briefly described as follows:
First, the cuff is tied to the arm, and the cuff automatically inflates. After reaching a certain pressure (generally 30~ 50 mmHg higher than systolic blood pressure), pressurization stops and deflation begins. When the air pressure reaches a certain level, the blood flow can pass through the blood vessel, and a certain oscillation wave appears, which propagates to the pressure sensor through the trachea, and the pressure sensor can detect the pressure and fluctuation in the cuff in real time. Gradually deflate, and the oscillation wave is getting bigger and bigger. Re-deflation Because the contact between the cuff and the arm is looser, the pressure and fluctuation detected by the pressure sensor are smaller and smaller. Select the time with the largest fluctuation as the reference point, and on this basis, look forward for the fluctuation point with the peak value of 0.45, that is, systolic blood pressure, and look backward for the fluctuation point with the peak value of 0.75, and the pressure corresponding to this point is diastolic blood pressure, and the pressure corresponding to the point with the largest fluctuation is average blood pressure. It is worth mentioning that the constants are 0.45 and 0.75. It is different for each manufacturer and should be based on the results of clinical tests. Moreover, it is also possible for large manufacturers to segment different blood pressures and set different constants.
Several international advanced enterprises have developed the pressurized synchronous measurement technology (MWI technology), that is, the technology of measuring blood pressure during pressurization, which greatly shortens the measurement time. At the same time, through the linear pressurization technology, the measurement accuracy is also greatly improved. Electronic sphygmomanometers are divided into two categories according to the place of use: medical electronic sphygmomanometers and household electronic sphygmomanometers.
Medical electronic sphygmomanometer is mainly used in public health such as hospitals, clinics, blood stations, blood collection vehicles, medical examination vehicles, health management examination centers, rehabilitation centers, sanatoriums, communities, schools, banks, factories, sports fields, etc.
Household electronic sphygmomanometer, mainly used in families. Family medical treatment has become the fashion of modern medical treatment. In the past, people had to go to the hospital to measure their blood pressure. Now, as long as they have a home electronic sphygmomanometer, they can monitor the changes of blood pressure at any time while sitting at home. If they find abnormal blood pressure, they can go to the hospital for treatment in time to prevent sudden attacks of diseases such as cerebral hemorrhage and heart failure. According to the international proposal "Provisions on the Revised Draft of Sphygmomanometer" put forward by the International Organization for Legal Metrology, the scale of sphygmomanometer was changed from mmHg to kPa. 1 kpa = 7.5 mmhg, the graduation value on the scale is 0.5kPa, and there are two scales on the sphygmomanometer, so please pay attention to it when applying. There are three forms of electronic sphygmomanometer, one is arm type, the other is wrist type and the third is finger type. Among the three types of electronic sphygmomanometers, the finger electronic sphygmomanometer, even for healthy people, has been proved to be unusable. It should be noted that wrist electronic sphygmomanometer is not suitable for patients with blood circulation disorders, such as diabetes, hyperlipidemia, hypertension and other diseases will accelerate arteriosclerosis, thus causing peripheral circulation disorders. The blood pressure measurements of these patients' wrists and upper arms vary greatly. It is suggested that these patients and the elderly choose the arm electronic sphygmomanometer. In addition, you should measure it on the spot before buying, so that you can choose an electronic sphygmomanometer that suits you.
Firstly, the principle of electronic sphygmomanometer technology has gone through two development stages: auscultation (also known as Coriolis sound method) and oscillometry (also known as oscillation method). Only a few companies use auscultation principle on electronic sphygmomanometer, while most mainstream electronic sphygmomanometer manufacturers use oscillometric principle. In view of the fact that the principle of oscillometric method is adopted by mainstream enterprises at present, the technical intergenerational division to be discussed here is the technical intergenerational division of oscillometric (also known as oscillation method) electronic sphygmomanometer.
The first generation of electronic sphygmomanometer (G 1-NIBPM)
Technology used: MWD technology (measured under reduced pressure)
Main components used: fast pressurizing air pump, electronic quick exhaust valve, mechanical constant-speed exhaust valve, pneumatic pressure sensor.
Measurement characteristics: quickly pressurize to a certain pressure value, deflate at a speed of 2~7mmHg/s through a mechanical constant-speed exhaust valve, and measure blood pressure during this deflation process.
Features 1: Two exhaust valves are adopted-electronic quick exhaust valve and mechanical constant-speed exhaust valve;
Feature 2: The initial pressurization is mostly set at about 200mmHg, which emphasizes that the pressurization speed should be fast, and usually reaches the set pressurization value within 10 second;
Feature 3: when the pressurization is just stopped, the deflation speed exceeds 7mmHg/s, and it can be stabilized at 2~7mmHg/s after a few seconds. Due to the instability (principle defect) of mechanical constant-speed exhaust valve, this generation of products will generally increase the initial boost pressure. For example, most domestic sphygmomanometers set the initial pressurization pressure at190 ~ 200mm Hg, which can overcome the measurement instability caused by the deflation speed when the pressurization just stops.
Its disadvantage is that the user's arm (or wrist) has obvious oppressive feeling, and at the same time, the measurement result is sometimes unstable because of the instability of the mechanical constant-speed exhaust valve.
The second disadvantage of mechanical constant-speed exhaust valve is that its exhaust speed is usually set according to the arm with medium thickness, but the arm of the actual user is thick or thin, which affects the measurement accuracy.
The third disadvantage of mechanical constant-speed exhaust valve is that the rubber in it begins to age in about six months to one year, and the exhaust speed set by the manufacturer is affected, which will eventually affect the measurement accuracy.
The fourth disadvantage of mechanical constant-speed exhaust valve is that even if the same person makes the same measurement, the exhaust speed is fast when the pressure is high and slow when the pressure is low. This will directly affect the accuracy of blood pressure measurement.
This generation of sphygmomanometer technology, Japanese manufacturers, mostly stopped using it more than ten years ago. And some domestic manufacturers who purchase electronic sphygmomanometers are mostly the first generation. And all solution providers only have this generation of technical solutions.
Second generation electronic sphygmomanometer (G2-NIBPM)
Technology used: MWD technology (measured under reduced pressure)
Main components used: booster pump, electronically controlled exhaust valve and air pressure sensor.
Measurement characteristics: Because of the servo technology of electronically controlled exhaust valve (ECV servo technology ogy), the speed of constant-speed exhaust is really constant, and it can be intelligently pressurized according to the blood pressure of the measurer, so the measurement result is more stable (and other factors).
Features 1: only one exhaust valve-electrically controlled exhaust valve is used, which is also used for constant speed exhaust and rapid exhaust after measurement;
Feature 2: Intelligent pressurization. That is to say, the sphygmomanometer will make a rough judgment on the blood pressure of the measurer in advance during the pressurization process, so as to determine the final pressure value to be added. Usually, the pressure value plus the systolic blood pressure of the measurer+30mmhg; Feature 3: the deflation speed can be stabilized at 3~4mmHg/s from the beginning.
The technical difficulty of this generation of electronic sphygmomanometer is the servo technology of electronically controlled exhaust valve. The first and second generation measurement technologies are also collectively referred to as MWD technology (measurement under reduced pressure), which corresponds to the following third generation MWI technology (measurement under increased pressure).
Third, the third generation electronic sphygmomanometer (G3-NIBPM)
Technology used: MWI technology (measured under pressure)
Main components used: servo booster pump, electronically controlled exhaust valve and air pressure sensor.
Measurement characteristics: the pressure is constant and there is no pressure during blood pressure measurement.
Features 1: servo pressurizing air pump is used to control the pressurizing speed and measure the blood pressure during pressurizing;
Feature 2: Only one exhaust valve-electronic quick exhaust valve is used to measure the rapid exhaust at the end. The technical difficulty of this generation of electronic sphygmomanometer is MWI technology (pressurized synchronous measurement), and there are roughly the following companies in the world that master this generation of technology: Jin Yidi, Omron and Panasonic.
The third generation electronic sphygmomanometer technology
MWI technology (with pressure measurement) has become the mainstream technology of wrist electronic sphygmomanometer, and Jin Yidi, Omron and Panasonic have eliminated the previous measurement technology.
On the application of the third generation electronic sphygmomanometer technology
Judging from the products of mainstream electronic sphygmomanometer manufacturers in the world, the first generation of electronic sphygmomanometer technology is basically on the verge of being eliminated; The second generation of electronic sphygmomanometer technology is mainly used for upper arm electronic sphygmomanometer; The third generation electronic sphygmomanometer technology is mainly used for wrist electronic sphygmomanometer.
The difference between the third generation electronic sphygmomanometer and the first and second generation electronic sphygmomanometer
The difference between the third generation and the first and second generation electronic sphygmomanometers is very obvious. The third generation electronic sphygmomanometer measures blood pressure during pressurization, and there is no slow exhaust process. After the blood pressure is displayed, exhaust quickly immediately. The first and second generation electronic sphygmomanometers need to be quickly pressurized to a certain pressure, and then slowly deflated, and the blood pressure is measured during the slow deflation.
Difference between the first and second generation electronic sphygmomanometer
The difference between the first generation electronic sphygmomanometer and the second generation electronic sphygmomanometer is that the first generation electronic sphygmomanometer uses two exhaust valves-electronic quick exhaust valve and mechanical constant speed exhaust valve; The second generation electronic sphygmomanometer only uses one exhaust valve-electrically controlled exhaust valve, which is used for constant speed exhaust and rapid exhaust at the end of measurement.
Encountered the following picture:
According to the pressurization mode of electronic sphygmomanometer, electronic sphygmomanometer can be divided into full-automatic electronic sphygmomanometer and semi-automatic electronic sphygmomanometer.
semiautomatic
In the early stage of the development of electronic sphygmomanometer, there was a semi-automatic electronic sphygmomanometer-manual pressurization electronic sphygmomanometer. Although most manufacturers have stopped the production of semi-automatic electronic sphygmomanometer, it is necessary to analyze its defects. When using semi-automatic electronic sphygmomanometer to measure blood pressure, manual pressurization will affect the blood pressure of the tested person, thus affecting the accuracy of blood pressure measurement! Of course, if there is a third party to help pressurize, the accuracy of blood pressure measurement is no problem.
full automatic
Compared with the semi-automatic electronic sphygmomanometer, the fully automatic electronic sphygmomanometer was developed later, that is, the electronic booster pump inside the sphygmomanometer pressurized the sphygmomanometer without the need for the subject to manually pressurize it. Fully automatic electronic sphygmomanometer overcomes the above shortcomings of semi-automatic electronic sphygmomanometer. On this basis, the intelligent pressurization technology of electronic sphygmomanometer is developed.
Intelligent supercharging
Intelligent pressurization means that the electronic sphygmomanometer will roughly judge the systolic blood pressure of the measurer in advance during pressurization, so as to determine the final pressure value to be added. Usually, the pressure value will be added to about +30mmHg of the systolic blood pressure of the measurer. Intelligent pressurization technology is mainly used in the second generation electronic sphygmomanometer. Corresponding to intelligent supercharging is fixed supercharging. Fixed pressurization refers to setting the initial pressurization value of the electronic sphygmomanometer at a fixed position, usually around 190mmHg. The first generation of electronic sphygmomanometers mostly used fixed pressurization technology.
What are the benefits of intelligent pressurization?
The first is comfort, because there will be no excessive pressure on the arm. For example, the systolic blood pressure 1.20 mmHg, and the pressurization value only needs to reach 1.50 mmHg. The second is accuracy. Intelligent pressurization can avoid the instability of blood pressure measurement caused by discomfort caused by excessive pressurization, thus avoiding the influence on measurement accuracy. Finally, it is quiet, because the intelligent pressurization technology needs to use a silent air pump, and the air pump with loud noise cannot be used for the intelligent pressurization sphygmomanometer. Therefore, using the electronic sphygmomanometer with intelligent pressurization technology will make users more comfortable and the measurement results will be more accurate.
Where is the difficulty of intelligent supercharging technology?
The difficulty lies in predicting the systolic blood pressure of the measurer while pressurizing, and the interference of the air pump is great when pressurizing, which makes it difficult to detect the blood pressure signal. Therefore, only a few manufacturers with the third generation electronic sphygmomanometer technology-pressurized synchronous measurement (MWI) technology have intelligent pressurization technology.
Reading assistance type
265438+At the beginning of the 20th century, scientists developed a more practical and simple reading-aid sphygmomanometer by further improving the traditional mercury sphygmomanometer and modern electronic sphygmomanometer, which brought the development of sphygmomanometer into a new stage. Compared with other sphygmomanometers, the invention has the following remarkable characteristics:
1, accurate measurement. The reading-aid sphygmomanometer adopts the only Kirchhoff sound measurement method recognized by the International Health Organization (WHO), and the measurement is accurate.
2, easy to use, no need to take off clothes and sleeves. The reading-assisting sphygmomanometer can directly measure through clothes with a thickness of less than 2 cm, thus avoiding the trouble of users taking off clothes and putting on clothes.
3. Electronic voice prompts blood pressure value. When measuring, there will be electronic prompts of "drip" and "drip" between high pressure and low pressure. The blood pressure value corresponding to the first sound is high, and the blood pressure value corresponding to the last sound is low.
4, can prompt other health conditions. The electronic prompt sound from the reading-aid sphygmomanometer can accurately reflect the heartbeat. Prompt tone is rapid, indicating that the heartbeat is too fast; The delay of prompt tone indicates bradycardia, and early diseases such as arrhythmia can be judged by the analysis of prompt tone. If the high pressure is too close to the low pressure, it means that the blood viscosity is too high; If the prompt tone appears every few seconds, the measurer may have intermittent heart disease.
5. Compared with the traditional electronic sphygmomanometer, the reading-aid sphygmomanometer is cheap and has a long service life.