Types of tonometers

Devices that measure blood pressure are divided into three types:

1. Mechanical (manual). The oldest and most common device, consisting of a cuff for putting on the shoulder, a bulb for pumping air and, directly, a measuring device - a manometer. A phonendoscope is required for a complete set, with which the heart rhythm is listened to.

The advantages are low cost and measurement accuracy. They do not require battery power and rarely break down.

The disadvantages are in the certain complexity of the process. If you do not have the skills, you can get a large error in the readings. In addition, the mechanical device does not measure the pulse, this has to be done manually, by placing your fingers on the wrist and counting the beats. Sometimes manual tonometers themselves can be guilty of incorrect readings, so it is recommended to periodically give them to a specialist for verification.

Mechanical tonometer.

2. Automatic tonometer. Consists of a cuff on the shoulder or wrist and a measuring device with a display and a built-in electronic sensor and compressor that pumps air into the cuff. This model is more expensive than a manual one, but it is easier to use and does not require special skills. Just put the cuff on, press the button, and the device will do everything itself. The disadvantage is the need for power (batteries or network), which you will have to constantly take care of. Doctors do not like automatic devices either, considering them a purely home diagnostic option. Although expensive models are quite accurate in their readings, they can malfunction, like any electronics.

Popular automatic tonometers

3. Semi-automatic. The device has an electronic sensor and display, like an automatic tonometer, but the cuff is not inflated automatically, but manually, using a bulb. The device has an average price compared to the two above-mentioned models. Among the advantages, it is worth noting reduced energy consumption, diagnostic functionality similar to an automatic tonometer, and among the disadvantages - perhaps manual inflation.

Semi-automatic tonometer.

4. Smart tonometer. A blood pressure monitor can be part of the functionality of a smart watch or fitness bracelet, but in this design it has not yet fully taken root, since it is a secondary function in gadgets. Portable smart tonometers are a transitional link from traditional automatic meters to smart watches with a blood pressure monitoring function. They also have a cuff and a measuring unit with a display, and the main difference is compatibility with a PC. This allows you to analyze readings with the help of special software, put them into graphs, keep statistics, transfer them to a smartphone via Wi-Fi or Bluetooth, and even perform voice measurements. And a smart tonometer can also replace a barometer and thermometer, recording the temperature and pressure of the environment. The only downside of a smart device is its high price.

Tonometers with PC connection

When choosing a tonometer, preference should be given to a device that you can use without outside help. For example, you should not buy a manual device if you do not have enough strength to inflate the cuff, and a smart one if you do not plan or cannot use its full functionality.

Functions and capabilities of tonometers

Each tonometer takes measurements in its own way. Let's consider the capabilities of all types in order.

Manual tonometer

The mechanical device requires some effort to obtain blood pressure data. It is necessary to apply the cuff to the shoulder and pump air into it with a bulb until the reading on the manometer exceeds the patient's usual upper (systolic) pressure by 20-30 points. Then gently release the valve. Air will begin to come out of the cuff, the pressure on the blood vessel will decrease, which will make it possible to hear the pulsation of the artery with a phonendoscope, and record the digital value on the dial of the manometer. The beginning of the pulsation will show the systolic pressure, and the end - the diastolic (lower).

A mechanical tonometer does not perform any other functions except for determining pressure. When buying, you should pay attention to the quality of the phonendoscope and connecting tubes. The accuracy of the readings directly depends on them.

Automatic and semi-automatic tonometer

Automatic and semi-automatic tonometers have a number of common properties:

  • lack of a pressure gauge and phonendoscope;
  • generation of readings using an electronic sensor with subsequent output to the display;
  • operation from batteries and/or the network.

Measurement of blood pressure in electronic devices is performed using a microprocessor, which recognizes not the pulsation of blood, but the vibrations of air in the cuff, and performs analysis and calculations using special algorithms.

Popular semi-automatic tonometers

In addition to measuring blood pressure, both types of tonometers also perform other functions, such as:

  • pulse measurement. Shows the number of heartbeats per minute;
  • calculation of average pressure. Derived from the results of the last three measurements;
  • storing measurement results in memory (from 30 to 200 readings with date and time of measurement);
  • arrhythmia detection. If the patient has an irregular pulse, a heart-shaped indicator on the display will notify about it.

Smart tonometer

A smart watch or fitness bracelet equipped with a blood pressure measurement function, depending on the model, may also have other activity and health monitoring capabilities, including:

  • pulse measurement;
  • counting steps, calories;
  • electrocardiogram (ECG) recording.
Fitness bracelets with heart rate monitor

When choosing a smart device for monitoring blood pressure, it is important to determine what the main goal is. If monitoring blood pressure and pulse is a secondary task, and you need more watch/fitness bracelet functions, you should choose them. If you need constant blood pressure monitoring with accurate readings, it is better not to combine several devices in one and specifically buy a smart tonometer, such as Xiaomi iHealth 2 .

The reliability of the blood pressure measurement algorithm in smart gadgets has not yet been fully studied. Although many predict a great future for them, and the development of smart technologies does not give reason to doubt this.

Fitness bracelet with tonometer.

Types and sizes of cuffs

The cuffs are placed on the shoulder or wrist. The first option is divided into three main types, depending on the patient's arm circumference:

  • children's (from 15 to 22 cm);
  • standard (22 – 32 cm);
  • universal (22 – 42 cm).

That is, we measure the circumference of the shoulder and see what numbers we get. In practice, the universal cuff is the most common and fits almost all adults, regardless of build.

There are cuffs of greater length, but not all manufacturers. Only leading brands, such as Omron or Microlife, offer a wide range of sizes.

With a wrist cuff, things are much simpler. Here it is important to focus only on your own comfort and take into account your age. A wrist tonometer will be more accurate for people under 50. This is due to the fact that the artery in the wrist is thinner than in the shoulder, and with age it becomes even weaker, so the data in older people with such a device may not be read correctly.

Wrist tonometer.

Types of power supply for tonometers

Mechanical meters do not require power, they work only from human muscle power. Smart devices are equipped with Li-ion batteries of different capacities, but in general the charge lasts for several days, and in some cases - months.

Automatic and semi-automatic tonometers operate from different power sources:

Batteries. Elements can be of the AA or AAA type (finger or microfinger). They serve from 1 month to a year, depending on the quality of the batteries and the device itself. The battery charge indicator, like on a mobile phone, can notify that the charge is running low.

A battery-powered tonometer is advantageous due to its autonomy, because you can take it with you on the road, take measurements in any convenient place, without being tied to an outlet.

Network/batteries. The devices are equipped with an adapter for a 220 V power supply, but also have a slot for batteries. The advantages of a tonometer with two types of power supply are obvious:

  • saves battery power, you need to buy it less often;
  • the user has no restrictions on movement;
  • The tonometer will still work even if the batteries are dead and there are no new ones at hand.
Tonometer with batteries and network adapter.

Battery. Tonometers with a battery are mobile, convenient, work for a long time, and recharging from the mains takes only a few hours. The main disadvantage of such devices is their short life. The average service life of batteries is 2 years, after which most tonometers are subject to disposal, since their design does not provide for battery replacement.

As we can see, the medical equipment market is full of offers of tonometers for every taste and budget. It is important not to get confused and buy the device that is most suitable for your body and which you can use without outside help. We hope that our article helped you with this.