Electronic sensors for analyzing the body composition of rituals. How to choose a scale that measures the mass fraction of fat and muscle mass in the body

Modern developments allow everyone who monitors their weight and health to evaluate important indicators body: find out the exact fat/muscle tissue/fluid content, metabolic status, biological age. By understanding how they work, you will ensure that the measurements taken are correct.

Operating principle of analyzers

The analyzer is an improved version of floor scales. A touch sensor that detects weight is built into the legs. Some analyzer models allow weighing to be carried out as an independent procedure, while others only carry out comprehensive study(which is not always convenient). The analyzer determines additional data by using the BIA (bioimpedance analysis of body composition) method. Its work is based on the electrical conductivity of tissues.

How does the analyzer work? A weak current is passed through the electrodes built into the platform from foot to foot (average values: 400 μA, 50 kNz) - this does not harm the human body and does not cause physical discomfort. Electrical conductivity tissues is different, which is reflected in the speed of signal transmission and makes it possible to determine body composition. Fat and bones have high resistance because they contain almost no liquid. The electrical resistance of muscles is lower due to its high content (70-75%). The indicators obtained by the analyzer are subject to software processing and displayed. Devices of different brands differ in their functionality - “pioneers” are characterized by the greatest information content and accuracy. The Japanese company Tanita was the first to introduce new technologies into the production of scales - the secret of success was the presence of its own medical research center. As a result of many years of research related to determining the effect of excess weight on physical health, the Tanita company released a professional analyzer scale (this happened in 1992). Continuing to work on the problem, specialists created the first household analyzers that could be used outside medical institutions to determine weight and body composition:

• muscle and bone mass;
• percentage of water and fat;
• shares of visceral fat.

Individual approach

The operating principle of Tanita analyzer scales is based on individual approach. The electrical resistance of human tissue depends on a number of factors, so to get an accurate picture you need to enter the necessary data (by programming the analyzer, you can create profiles for yourself and all family members). Measurements are compared with:

• floor;
• height;
• age.

To use the detection function daily consumption calories the user must set the level physical activity. It will be useful for women to enter information about menstrual cycle(an analyzer with such a function will make a “discount” on critical days, indicating that the fluid rate has increased situationally).

The technique used is capable of working with high accuracy, but it is necessary to take into account the influence on the operation of the analyzer of such factors as:

• nutrition and physical activity (measurements should be taken no earlier than 3 hours after playing sports or eating);
• surface vibration (this factor must be excluded);
• poor contact with the electrodes (the scales need to be cleaned bare feet, ensuring that the heels are located in the required area of ​​the measuring platform).

Please note: since the analyzer operates based on the passage of electric current, there are contraindications for determining body composition. People with implanted medical devices (pacemaker, etc.) can only use the device to determine their weight (Tanita analyzers are capable of operating in this mode). Despite the fact that Roszdravnadzor confirms the safety and high quality Tanita analyzers, yet manufacturers do not recommend using them during pregnancy (you can control weight, but not body composition).

The operating principle of the analyzers is simple and clear, but the device itself is quite complex system, requiring strict adherence to operating rules (carefully read the instructions). You need to check your weight and control the ratio of muscle and fat tissue at the same time under the same conditions (a systematic approach is important, otherwise it will be impossible to track the progress of your work on yourself).

The main purpose of the scale is to determine body weight. But the models we tested have an additional feature: by standing on them, you can find out how much fat and how much water is in your body. However, not everyone can use such devices, because during the procedure an electric current passes through the body.

Know yourself

Health is on the scales

When conceiving this test, we wanted to “test for accuracy” the most popular models of electronic household scales. But when we came shopping, we learned that for “the same money” – from 900 to 2300 rubles you can buy not just electronic scales, but body composition analyzer scales. Models in this price group from chain stores household appliances and took part in the test: Cameron BFS-333, Vitek VT-1953 BK, Bork SC EFG 4315 TR And Tefal BodyUp. Later we learned that Tanita was the first to create such scales, so we purchased a model from the Medtekhnika store Tanita BC-532(3200 rubles). At first they wanted to take it as a standard in determining body composition. And then they decided not to create idols for themselves and test them on a general basis.

Table 1 "Specifications and measured parameters of floor scales-analyzers"

Under load

To check the accuracy of the samples, we sent them to the laboratory. There, reference weights were installed on the platform of each model, weighing from the minimum to the maximum value specified in the instructions. Thus, according to manufacturers, all models can withstand up to 150 kg, and scales Tefal– up to 160.

Under the heaviest load, all the scales held up well, only two made the experts worry - plastic Cameron and glass Bork. The first ones creaked desperately, and the second ones had to be placed with the greatest care. But in the end everything worked out - the maximum weight was reached.

Courtesy of Kings

Based on the results of all measurements, the Tanita sample turned out to be the most accurate - it has almost zero error and the highest stability of readings. Laboratory specialists assumed that these scales were calibrated and verified at the factory.

In second place in terms of accuracy were scales Bork– error is only +0.1 kg. This is very good for household scales.

Vitek(-0.2 kg) and Cameron(+0.2 kg) also showed a good result, corresponding to GOST. The readings for both are stable.

Here's a sample Tefal, on the contrary, demonstrated low stability. With the same load, it showed different weights, and deviations reached 0.5 kg, which does not meet the standards. You should not trust such scales, because when the readings fluctuate, it is impossible to determine whether you are gaining or losing weight.

Hold me!

Stepping on the scale is not a tricky thing. But how safe is it? The laboratory staff checked this too.

Let’s say right away: there were no samples that were one hundred percent stable. This is due to the design features of electronic scales. The fact is that the touch sensor (weight detector) is built into their legs, and to prevent the scales from turning over during weighing, you need to stand strictly on the zones intended for this. Safety also depends on the material from which the platform is made and its size.

Model Cameron a bit tall, but quite stable due to the width and weight of the platform. Transverse relief stripes will prevent you from slipping on it.

Feet practically do not slip even on scales Tefal made of matte plastic. However, if you stand on the platform not exactly in the center, the scales may tip over.

The model should be used with great care Bork– its surface is entirely made of smooth glass, which is easy to slip on.

Scales are recognized as the most unstable Tanita. Their developers sacrificed safety for the sake of design delights. The platform of this model is raised almost like a skateboard, and the surface has a surreal shape, with slight differences in height. The areas for the feet are combined from glass and metal, so they cannot be called anatomical.

Rabbits are not only valuable fur...

Knowing your weight is, of course, important. But it is equally important to understand why we gain or lose weight. For example, are we losing weight due to water loss? Does your weight stay stable because fat is transferred to muscle? Or maybe the person just has a “heavy bone”?

Modern scales with a body composition analyzer provide answers to these questions, as they determine the ratio of fat and water in the body. A model Tanita also distinguishes muscle tissue from bone, tells you how much fat you have accumulated on your internal organs(visceral fat), and at the same time determines biological age.

Believe it or not?

How to check the accuracy of the body composition analyzer readings? Isn't this quackery?

In search of an answer, we turned to the clinic of the Institute of Nutrition of the Russian Academy of Sciences, to the office of bioimpedancemetry (measurement of body composition). The owner of the office, a senior researcher at the clinic, Candidate of Medical Sciences Yunna Pavlovna Popova, explained the principle of operation of such devices, and then made a control measurement on a laboratory device for bioimpedance analysis of body composition. We took the data obtained as a standard and compared the average readings of our models with them.

Almost all test samples, except one, showed very good result– deviation from the standard is no more than 1–2%. And only scales Bork They made a mistake with the definition of fat: they flatter their owners by claiming that their body fat is 6-7% less than it actually is. This is such an optimistic analyzer with built-in “rose-colored glasses”.

It's better not to take risks

Having learned that the bioimpedance analysis procedure involves passing an electric current through the body, we decided to find out whether this is harmful to health. And can everyone use such scales?

It turned out that there is no clarity on this issue. The instructions for some models state that they are contraindicated for pregnant women and those who use a pacemaker. The instructions for others say that there are no contraindications for pregnant women. With a pacemaker, everything is clear - an electrical discharge can really cause malfunctions in its operation. But the question remains open regarding contraindications for pregnant women.

It is known that expectant mothers often weigh themselves: they need to monitor how their body weight increases as the fetus develops. What will happen if they buy not simple scales, but scales with an analyzer? Moreover, there are more and more such models on sale.

We again turned to Yunna Pavlovna Popova with this question. She replied that there are no special contraindications to the use of bioimpedance measurements for pregnant women. However, guided common sense, women expecting to add to their family are better off not taking risks and not using the analyzer. And if such scales have already been purchased, you can simply disable the additional function. By the way, four out of five tested models are Tanita, Vitek, Cameron And Bork provide this opportunity. And only as a sample Tefal“weighing only” mode is not provided.

Not for all

Another important question: Is the body composition analyzer scale easy to use? With models Vitek, Cameron And Bork There are no difficulties thanks to detailed instructions. In addition, the basic functions of these scales (“switch on”, “weighing only”) can be understood intuitively.

At the sample Tanita There are 13 buttons, while the rest have no more than 4. However, the thoughtfulness, logic, clarity and excellent description of the functions of each key in the instructions make this model easy to operate.

But in the instructions for the scales Tefal Not only is it not said how to use the “fat analyzer,” but there is not even information on how to turn on the scale. True, on the packaging itself with reverse side Among other advertising inscriptions you can find the phrase: “ Automatic switching on when standing on the platform.” And although the automatic operating principle of this device is quite convenient (the user has to perform a minimum of actions), the lack of a description in the instructions can make the purchase useless.

table 2"Test results of floor scales-analyzers"

Test conclusions:

• Tanita BC 532– original shaped scales with pharmaceutical precision and advanced analyzer functions. This is the most expensive test model (3,200 rubles), but, alas, not the most stable.
• Vitek VT-1953 BK– accurate, stable and convenient scales for a reasonable price (RUB 1,400).
• Sample Cameron BFS-333 demonstrated the best price-quality ratio (900 rubles). The scale and fat analyzer readings are accurate and stable.
• At the scales Bork SC EFG 4315 good weighing accuracy. But this device is let down by the slippery glass surface and significant discrepancies between the fat analyzer readings and the standard.
• Model indications Tefal BodyUp 2024 They are not accurate and stable enough, and the instructions do little to help you master the controls. In addition, it is impossible to simply weigh yourself on a scale by turning off the electric current.

Brief characteristics of the models

• TANITA BC-532

  VITEK VT-1953 VK

  Advantages: Accuracy and stability of readings within the standard. High accuracy body composition analyzer. The most stable dough model, light and compact. The scales are turned on by tapping on the body. The areas where the feet are located are clearly defined. The supporting surface is made of non-slip plastic, pleasant to the touch.

  Flaws: Small display. The scale may turn on spontaneously, for example during transport. This shortens the battery life.

  We would like to thank you for your assistance in conducting the tests:

  • Nazarov Vladimir Nikolaevich, Candidate of Technical Sciences, Head of the Department of “Metrological Support of Weighing Equipment” of the All-Russian Research Institute of Metrological Service, (FSUE “VNIIMS”);
  • Popova Yunna Pavlovna, candidate of medical sciences, senior research fellow clinics of the Institute of Nutrition of the Russian Academy of Medical Sciences.

1. Accuracy is a guarantee of the quality of the equipment presented.
2. The products are the result of careful development and an excellent manufacturing process.
3. Calibration may be required after 300 thousand sessions, and if necessary, regional service centers will perform cost-effective and quick repairs.

A good investment option is in highly progressive scales under the Tanita brand!

Many medical centers and world-famous fitness clubs were convinced of the advisability of deciding to buy a body composition analyzer from TANITA. First of all, this is due to the design of the device, like this one. The basis is unique technique analysis of bioelectrical resistance.

For full inspection the patient is placed on the platform of the measuring installation, after which safe and practically imperceptible low frequency currents. As a result, the state of muscle, fat, bone mass, various indices and levels of determined components are assessed. The data is recorded and submitted for printing.

Depending on the model, the water/fat/muscle ratio may be assessed. For this purpose, it is best to buy scales with a fat analyzer. They usually run on batteries and have useful options such as “Auto power off”, “Weight only”, “Athlete”. If necessary, previous data can be recalled, while the memory is designed mainly for 4-5 people.

For our visitors, we also offer Tanita segment-based analyzer scales, which you can buy at a very affordable price. Other models can surprise you with their design style, large touch screen and auto-detection of the personal user. Therefore, look at the catalog and you will definitely find the required control and measuring equipment.

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How body composition analyzers work

Body composition analysis devices help to understand many aspects. They come to the aid of nutritionists, fitness trainers, athletes and just people leading healthy life. Allows you to monitor the body and find out:

1. presence of excess body weight;
2. volume of body fat;
3. metabolic level;
4. muscle mass ratio;
5. degree of obesity;
6. the presence of internal fatty tissue;
7. the number of calories needed;
8. condition of the skeletal system.

Thus, they help determine how high the risk of cardiovascular diseases, diabetes and even some types of cancer is. Determine effectiveness physical activity in accordance with muscle growth. Allows you to find out at what metabolic age health approaches. Of course, this is a lot. But what is the determination mechanism? How do new generation scales work with a body composition analyzer?

Operating principle of diagnostic scales

The peculiarity of the functioning of devices for analyzing body composition and the state of the body is associated with the ability of tissues to resist the passage of electrical impulses. More precisely - electric current. This technique has its own name - BIA (BIA, bioelectrical impedance analysis). It is based on calculating the electrical resistance of various tissues when current is passed through them. Of course, safe, low intensity.

Organic mass, which does not contain fat, easily passes such impulses. This is due to the sufficient presence of liquid in them. In muscles it reaches a concentration of 75%. Whereas in fatty tissue its volume is minimal. Hence the higher resistance (impedance) to electric current.

Typically, 400 μA (small direct current) of a constant frequency of 50 kHz, which is sent between the electrodes, simply passes through the body. And reducing the standard voltage between them makes it possible to calculate the impedance. The received data is subjected to software processing - BIA. All body composition analyzer devices are equipped with it.

Methods of calculations and their meaning

Body composition analyzers instantly calculate and display the total presence of water in the body. It is usually proportional to the degree of resistance electric current. It also instantly indicates lean (skinny) and fat mass. The latter is calculated by establishing the difference between lean mass and nominal body weight.

Impedance (resistance of biological tissues to electrical impulses) consists of 2 components:

• active resistance;
• reactance.

The specific characteristics (properties) of fluids present in the body determine the component of its active resistance. Cell membranes act as capacitors in it. They contribute a reactive component, which is directly dependent on the frequency of the electrical pulse.

Finding out the impedance in different frequency ranges(200 kНz and 5 kНz, for example) using predictive equations it is possible to obtain the results of ECW (extracellular water) and TBW (its total content in the entire body). Data on the presence of ICW (intracellular fluid) are then calculated by normal subtraction. Further. ECW readings may be related to ECM (extracellular mass). Whereas ICW – with information on the level of BCM (cell mass).

How do scales with a body mass analyzer work?

A safe low-frequency pulse is passed through metal electrodes mounted in the platform of the analyzer scales. When a person stands on them, the signal travels through the body. And the different resistance of parts of the body helps to establish the exact ratio of water and fat, which contains much less moisture than muscle mass.

Then the resulting resistance is compared with the age, height, and gender of the person being studied. And a personal calculation of fat levels and other body composition indicators is displayed. It is also possible to obtain data on metabolic age, abdominal fat volume, etc. The accuracy of body composition analyzers is achieved through:

• size and location of electrodes;
• the quality of the formula used for calculations;
• reliability of weighing readings.

The first depends on technical knowledge, the second on research skills, the third on the reliability of the weighing mechanism. The quality of the analyzer platform also plays an important role.

You can buy a body composition analyzer in our store at a discount 5 %. To get a discount use the promo code: DISCOUNT2017