Definition of Doppler Effect

The Doppler effect is a phenomenon in which an apparent change occurs in the frequency of sound, or in the wavelength of light, which is due to the movement relative of the entity that emits it in relation to an observer who is fixed.

If a sound source approaches a fixed observer, it will emit a higher-pitched sound than when it is moves away from him, which commonly occurs when hearing the characteristic sound of an ambulance in movement. In the case of light, when a light source gets closer it takes on a bluish hue while when it moves away it tends the color red, this is not always visible to the naked eye, being necessary to use instruments to be able to put it in evidence.

The Doppler effect has a large number of uses in different fields, in the case of sound it is of great useful in the detection of objects that are outside the visual field such as radar and in the location satellite by GPS. It is also used to locate submerged objects in seas and oceans, or to decide the course and velocity of military targets.

In the case of light, astrophysicists have been able to use this effect to determine the movements of stars and galaxies, it has also highlighted the fact that the universe is in a process of expansion and not close up.

One of the areas of knowledge in which he has had the greatest app It is in medicine, specifically in the diagnosis by imaging through ultrasound studies in the cardiovascular system, in this sense cardiac ultrasound or echocardiogram allows to visualize the dimensions of the various cavities of heart and the vessels that arrive and depart from it, as well as the pressure inside them, which allows a large number of diagnoses without the need to resort to procedures invasive.

The speed and direction of blood flow can also be identified, which makes it possible to reveal abnormal conditions such as obstructions. to the flow compatible with stenosis, or its abnormal retrograde flow known as regurgitation in states of insufficiency of the different valves. This is best visualized with the doppler effect added to the ultrasound showing the blood flows being approach the observer in blue and those who move away in red, thus being able to identify the meaning of said flow. It is also used in the evaluation of the blood vessels of the extremities, both in the arterial and venous systems.