The surface areas of three-dimensional figures known from the school course of stereometry, such as a cube, parallelepiped, pyramid, prism, cylinder and others, are not difficult to calculate. Their sides and bases are the simplest. They can be squares, rectangles, triangles, circles, and so on. If the figure is more complicated, it is divided into small ones and the areas of their surface faces are added up. Thus, they achieve the desired result. But if a certain object of volumetric space is endowed with the most intricate shape, for example, the human body. The area formula in this case is not so simple. Moreover, each of the people is endowed by nature with their own characteristics.
Practical application
But why do such calculations at all? In addition to scientific interest, the practical importance of this is undeniable. And a striking example of this is medicine and physiology. From skinsurface depends on air exchange with the surrounding space. From the area of the body - metabolism, that is, the internal metabolic processes of the body. These include the processing of food elements, turning it into the smallest particles and removing unnecessary substances. The mechanics of the most important human organs, which means he alth and life, depend on proper metabolism.
Body weight is largely built from adipose tissue, which can be observed in the body as an excess or deficiency. Therefore, the weight of a person is not always able to be an indicator of the metabolic process due to individual characteristics. With this in mind, in medicine it is believed that the surface area of the human body is an important factor. Therefore, its formula is considered necessary.
Chemotherapy
Chemotherapy often plays an important role in getting rid of infectious and parasitic diseases. Usually it has a greater effect than the treatment of drugs known to science today, while sometimes giving less negative consequences for the body. Its purpose is the destruction of infectious agents or parasites, and not a simple correction of violations, as occurs in the case of the use of pharmacological methods. The result is the restoration of organ functions. The same method is used to rid the patient of cancer cells, which in many cases has a tangible result.
The exact formula for human body area for chemotherapy is very important. Based on this indicator, the dose is calculatednecessary drugs. Without knowing this, it is difficult to expect a positive outcome.
Other uses
Knowing the area of body cover opens up additional opportunities for physiological research. Its characteristics for different ages can be calculated and systematized. Here, the chance is significantly increased not only to detect a tendency to obesity and other diseases in time, but also to conduct valuable scientific research based on the data obtained.
Such calculations are needed to calculate the dosage of drugs with great accuracy, drugs that have an extremely compressed therapeutic index, that is, a small border between the dose that causes a positive effect and harms the body. This is vitally important not only in chemotherapy, but also in the appointment of hormonal agents. Ultrasound examinations of cardiac functions also require knowledge of the formula for the area of the human body. In addition, it is used to study the intensity of glomerular filtration in nephrology. This is an important indicator of the study of kidney activity.
How to measure?
There are special formulas for calculating the area of three-dimensional geometric shapes. Most of them were bred in antiquity, and modern people recognize them from reference books and school textbooks.
It is also easy to calculate the volume of the human body, even despite its complex parameters. The great Archimedes coped with a similar task. He found that it is enough to immerse an object in a tank filled to the top with water, and collect the liquid displaced by it in a vessel, then the volume of water,which is easy to measure, and will be equal to the volume of the body. According to a legend that came to us from ancient times, such a simple, like all ingenious, idea came to the great ancient Greek scientist while he was taking a bath.
What would Archimedes say?
But what about the formula for calculating the area of a human body? Here, even Archimedes would have found it difficult to answer, this, at first glance, elementary task turns out to be so difficult. Let us immediately clarify that by area we mean not at all the outlines of the human body, which can be obtained by leaning it against the wall and chalking around the silhouette. This refers to the surface of the skin. But how to measure it? After all, the skin cannot be removed, like clothes, and spread out on the floor, make the necessary measurements.
Of course, you can cover someone from head to toe with a band-aid, then remove it and measure the surface area. There is also a chance to try to cover the entire body of a person with napkins, but neatly, evenly and without overlaps. And then remove all the elements, recalculate and multiply by the surface area of one napkin. However, this is too cumbersome and complex process, in reality it is almost impossible to implement. Moreover, the probability of error is so high! But still, people, in the end, found a solution to this problem.
Calculation principles
The first formula for such calculations was developed by the American Dubois. All calculation methods proposed later, purely fundamentally, do not differ much from the indicated method. They useindicators of body weight and height of a person, that is, its length, raised to a certain degree. Then their product is multiplied by a coefficient less than 1 calculated in advance in a practical way. This is the most convenient option, since without such a formula, measuring the area of a human body is an extremely complicated process in terms of spatial geometry.
Most of the methods require data on the weight and height of a person to calculate. However, in the Livingston and Scott calculation, only the mass is used. This is also characteristic of the Costeff and Mattard formulas.
Example
Yu's method can be cited as an example of calculating the area of a human body. This formula is the simplest, and therefore in our time has become widespread. It is similar to the Mosteller method. Here, the numerical values \u200b\u200bof height and weight are raised to the power of 0.5 (that is, the square root is extracted). And then the result is multiplied by 0.015925. In this case, the mass should be converted to kilograms. The length is taken in centimeters. For all that, the value of the area is obtained in square meters, and this circumstance should also be taken into account.
Now it is easy to calculate the surface area with a height of 169 cm and a weight of 64 kg. After calculating the square roots of the proposed values, it will be 0.015925 x 13 x 8. The final result will be after rounding 1.66m2.
Having figured out how to calculate the surface area of the human body and the formula, you can now do similar calculations for variousages under certain parameters and, if desired, to compile tables and diagrams from them. They help reveal the overall pattern of changes in body surface area during a person's life from infancy to adulthood.
Below is the data for boys aged 8 to 12, calculated according to Dubois.
Dubois nomogram
But is it possible to find out all the data without inconvenient calculations? Clearly, without complications and formulas, the area of a person's body can be found using a nomogram. It was also proposed and compiled by Dubois. It is presented below. How to use it?
The numbers on the horizontal indicate the weight of the body, on the vertical - the height of the person. To find out the surface area according to this nomogram, it is necessary to mentally draw perpendicular lines horizontally and vertically from the desired indicators until they intersect. The resulting point on the presented curves will show the desired result, according to Dubois's calculations. For example, using a nomogram, it is easy to find out that with a height of 160 cm and a weight of 75 kg, the body surface area will be 1.8 m2.
Medicine and mathematics
After considering the issue, we realized that knowledge about the area of the human body and the formula by which it is possible to determine it, which is so necessary for a he althy life, is provided by mathematics.
And this is far from the only information that doctors can get fromscience queens. After all, the language of numbers in this world can express almost everything. The geometry of the human body is a huge world full of amazing discoveries. And many organs: joints, bones and muscles, it is no coincidence that they got their name from the name of geometric shapes. Mathematics is also important in genetics, ophthalmology, medical statistics and many other areas of medicine.
Indicators of height and weight are necessary for the correct calculation of the diet. After all, accurate measurements of human organs, both internal and external, are essential for the manufacture of modern electronic prostheses, and not just damaged limbs. Nowadays, even artificial heart valves are being produced and successfully used in practice. And this is just another one of the possible bright examples.
