MEDICAL APPLICATIONS OF VOLUME | REAL LIFE MATH

 

As you probably know “An object’s volume describes the amount of space it contains”. But, have you ever thought what could be the practical applications of volume?

In medicine, volume measurements are used to characterize brain damage, lung function, sexual maturity, anemia, body fat percentage, and many other aspects of health. A few of these uses of volume are described below.

1.) Brain Damage from Alcohol

Using modern medical imaging technologies such as magnetic resonance imaging (MRI), doctors can take three-dimensional digital pictures of organs inside the body, including the brain. Computers can then measure the volumes of different parts of the brain from these digital pictures, using geometry and calculus to calculate volumes from raw image data.

MRI volume studies show that many parts of the brain shrink over time in people who are addicted to alcohol. The frontal lobes—the wrinkled part of the brain surface that is just behind the forehead—are strongly affected. It is this part of the brain that we use for reasoning, making judgments, and problem solving. But other parts of the brain shrink, too, including structures involved in memory and muscular coordination. Alcoholics who stop drinking may regain some of the lost brain volume, but not all. MRI studies also show that male and female alcoholics lose the same amount of brain volume, even though women alcoholics tend to drink much less. Doctors conclude from this that women are probably even more vulnerable to brain damage from alcohol than are men.

2.) Diagnosing Disease

Almost half of Americans alive today who live to be more than 85 years old will suffer eventually from Alzheimer’s disease. Alzheimer’s disease is a loss of brain function. In its early stages, its victims sometimes have trouble remembering the names for common objects, or how they got somewhere, or where they parked their car; in its late stages, they may become incurably angry or distressed, forget their own names, and forget who other people are. Doctors are trying understand the causes of Alzheimer’s disease and develop treatments for it. All agree that preventing the brain damage of Alzheimer’s—starting treatment in the early stages—is likely to be much more effective than trying to treat the late stages. But how can Alzheimer’s be detected before it is already damaging the mental powers of the victim?

Recent research has shown that the part of the brain called the hippocampus, which is a small area of the brain located in the temporal lobe (just below the ear), is the first part of the brain to be damaged by Alzheimer’s. The hippocampus helps the brain store memories, which is why forgetting is one of Alzheimer’s first symptoms. But instead of waiting for memory to fail badly, doctors can measure the volume of the hippocampus using MRI. A shrinking hippocampus can be observed at least 4 years before Alzheimer’s disease is bad enough to diagnose from memory loss alone.

3.) Pollution’s Effects on Teenagers

Polychlorinated aromatic hydrocarbons (PCAHs) are a type of toxic chemical that is produced by bleaching paper to make it white, improper garbage incineration, and the manufacture of pesticides (bug-killing chemicals). These chemicals, which are present almost everywhere today, get into the human body when we eat and drink. In 2002 scientists in Belgium studied the effects of PCAHs on the sexual maturation of boys and girls living in a polluted suburb. They compared how early boys and girls in the polluted suburb went through puberty (grew to sexual maturity) compared to children in cleaner areas. They found that high levels of PCAH-related chemicals in the blood significantly increased the chances of both boys and girls of having delayed sexual maturity. Once again, volume measurements proved useful in assessing health. The researchers estimated the volume of the testicles as a way of measuring sexual maturity in boys, while they assessed sexual maturity in girls by noting breast development. This study, and others, show that some pollutants can injure human health and development even in very low concentrations. Testicular volume measurements are also used in diagnosing infertility in men.

4.) Body Fat

Doctors speak of “body composition” to refer to how much of a person’s body consists of fat, muscle, and bone, and where the fat and muscle are located on the body. Measuring body composition is important to monitoring the effects of diet and exercise programs and tracking the progress of some diseases. Volume measurement is used to measure some aspects of body composition.

For example, the overall density of the body can be used estimate what percentage of the body consists of fat. Measuring body density requires the measurement of the body’s weight—which can be done easily, using a scale and two volumes.

The first volume needed is the volume of the body as a whole. Since the body is not made of simple shapes like cubes and cylinders, its volume cannot be found by taking a few measurements and using standard geometric formulas. Instead, its volume must be measured by submerging it in water. The body’s overall volume can then be found by measuring how much the water level rises or, alternatively, by weighing the body while it is underwater to see how much water it has displaced. (Underwater weighing is the same method used to measure the density of jewelry containing mixed metals). The body’s overall volume is equal to the water displaced.

However, doctors want to know the weight of the solid part of the body; the air in the lungs does not count. And even when a person has pushed all the air they can out of their lungs, there is still some left, the “residual lung volume.” Residual lung volume must therefore also be measured, as well as overall body volume. This is done using special machines that measure how much gas remains in the lungs when the person exhales. The body’s true, solid volume is approximately calculated by subtracting the residual lung volume from the body’s water displacement volume.

Dividing the body’s weight by its true, non-air volume gives its density. This is used to estimate body fat percentage by a standard mathematical formula.