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High or low blood pressure is a fairly common problem. Most people, especially the elderly, need constant monitoring of blood pressure and heart rate. For this, blood pressure monitors are designed, which can be used without problems at home. It is important to understand that pressure control allows you to identify serious diseases or their consequences in time. In addition, the doctor can get a more complete picture of the disease, based on the readings of the tonometer.
The modern market provides a huge variety of different models of tonometer for use at home. In general, tonometers can be divided into 2 types: mechanical and automatic.
Both the first and the second are equally popular and in demand among the population. Automatic devices are more modern and are becoming more and more in demand every day. There are mechanical blood pressure monitors in almost every home and medical institution.
Purpose of the device
The tonometer is able to detect deviations in blood pressure from the norm. It is known that normal pressure is 120 and 80 millimeters of mercury. Naturally, the norm is different for everyone and can vary within 10 units above and below the indicated numbers.
Such a device must be in the first-aid kit of every person, regardless of age. If a person suffers from hypertension, he should even have a tonometer at home. To avoid a hypertensive crisis, such patients should systematically assess blood pressure. Based on these results, the doctor can choose the necessary treatment.
It is important to understand that pressure can increase not only due to illness, but also one-time due to increased physical exertion and as a result of a deterioration in overall well-being. If a person often has dizziness, nausea, pain in the head and heart, this may indicate deviations in blood pressure readings from the norm.
Principle of operation of the device
Blood pressure can be measured by two methods: Korotkoff and oscillometric. It depends on the model of the tonometer. The Korotkov method involves listening to the pulse with a phonendoscope. The oscillometric method involves displaying the result immediately on the screen. It should be noted that both in the first and in the second case, the principle of operation is the same.
A cuff is put on the arm in the area of uXNUMXbuXNUMXbthe shoulder or wrist – a sleeve that has a pneumatic chamber inside. This sleeve is supplied with air, which increases its size. Thus, the arteries are compressed and the blood flow is blocked. If a phonendoscope is used to measure pressure, then at this moment all sounds disappear due to the fact that blood does not flow through the veins.
The blower is equipped with a valve that releases pressure gradually. As soon as the blood begins to circulate again, a person hears a knock (pulse) through the device. Thus, the indicator of the upper (systolic) blood pressure is fixed – it shows the pressure in the arteries at the moment when the heart contracts and pushes blood into the arteries. Further, the blood flow begins to increase, but after it is fully restored, the audible sound stops – this is an indicator of the lower (diastolic) blood pressure – it shows the pressure in the arteries at the moment of relaxation of the heart muscle. Automatic devices do not need human intervention, since the result is determined using electronics.
Classification of tonometers
Tonometers are classified according to the method of measurement:
- on the shoulder;
- on the wrist;
- on thumb.
The device that is worn on the finger is the least accurate, however, it can also correctly determine the pressure. It is very compact and easy to use. Most often it is used to measure blood pressure in athletes, as it takes a minimum of time.
The carpal tonometer is also very convenient to use, because there is no need to take off your clothes to measure. It is suitable for those people who lead an active lifestyle. The device is small in size, so you can easily take it with you to work, on a trip or just for a walk. In addition to blood pressure readings, it also displays a heart rate reading. For this reason, it is sometimes referred to as a heart rate monitor.
A device with a cuff that is worn on the upper arm is the most popular. He appeared first and is still quite common. Such a tonometer can be automatic and mechanical.
Automatic blood pressure monitors
Automatic blood pressure monitors are very convenient, because they do not require any special skills. To measure, you just need to position the cuff correctly on your arm. They do not require human assistance, they are fully automatic. Such devices are ideal for older people whose limbs are already weakened. To get started, you need to put on the cuff and press the button. The result then appears on a small screen.
There are models that provide a clock, voice messages and other additional features. It should be noted that depending on the number of functions, the price of the device changes.
These devices operate on batteries. Some models have network adapters that allow you to use the blood pressure monitor when connected to a network.
The disadvantages of such a device may be a small error, high cost and large dimensions. You also need to make sure that the battery does not sit down or the battery is discharged.
There are also semi-automatic tonometers. Their difference from automatic ones is that the cuff needs to be filled with air using a special pear. Otherwise, the result is also displayed on a small display, as in an automatic device.
The semi-automatic device is easy to use and is more affordable. Its advantage is a wide functionality for a small price, the absence of self-calculation of pressure indicators, as well as an electronic form of the results. In addition, there is no need to constantly change the batteries, as the cuff is filled with air manually. The disadvantage is a small error.
Mechanical blood pressure monitors
Mechanical devices are highly accurate, which is why they are most often used by medical professionals.
Such blood pressure monitors require some skills, good vision and hearing, because the pressure is determined by a person.
Such models are convenient to use in domestic conditions. The cuff has a special metal ring with which you can put it on your arm yourself. In addition, due to the different sizes of the cuff, it can be used by both children and adults. The advantage of this tonometer is high accuracy, affordable price, long service life. The disadvantages include the fact that the device requires certain skills and it is inconvenient for them to measure pressure on themselves.
Cuff for tonometer
The cuff is made of fabric, inside of which there is a rubber chamber and Velcro. It is worn on the wrist or shoulder. In addition, this part of the tonometer can have different sizes, so it can be chosen according to the circumference of a person’s arm.
For convenience, there are 3 main sizes:
- children;
- average;
- big.
The wrist blood pressure monitor also has a cuff, but usually its size is very small, so it is unlikely to be suitable for a full person.
Rules and Recommendations
The accuracy of the tonometer readings depends not only on its type, but also on human behavior. If you follow some simple recommendations, the result will be as accurate as possible.
Half an hour before the start of measuring blood pressure, it is not recommended to smoke and drink drinks containing caffeine: tea, coffee. You can not measure the pressure at a time when a person is nervous or too tired. Also, do not measure after training and taking a bath.
Inaccurate readings can also occur after a heavy dinner, and if a person suffers from constipation. The condition should be calm, and the stomach and intestines should not be overcrowded. The ideal time to measure blood pressure is 1-2 hours after a meal.
In addition, the electromagnetic field also affects the quality of the tonometer, so you should not keep a phone near the device. It is recommended to measure pressure in a sitting position with a straight back, do not cross or bend your legs, or in a prone position, but so that the arm lies along the body.