Whether it is a health checkup or a hospital visit, doctors always ask their patients to undergo ultrasound. Most people understand ultrasound to mean that a pregnant woman should have an ultrasound, but the truth is that ultrasound is not only used to examine the fetus, it is only a small part of the clinical application of ultrasound. But what exactly is ultrasound? How does it examine the human body?
Ultrasound, that is, ultrasound, which is a mechanical wave. Our human ear can hear the frequency of sound waves for 20 to 20 000 Hz. when the vibration frequency of sound waves is greater than 20 000 Hz or less than 20 Hz, we will not hear. Therefore, we will be higher than the frequency of 20 000 Hz sound waves called "ultrasound". Ultrasound has good directionality, strong penetrating ability, easy to obtain more concentrated sound energy, in the water to spread far and so on, can be used for measuring distance, speed, cleaning, welding, stone crushing, etc., in medicine, military, industry, agriculture is widely used.
Usually used for medical diagnosis of ultrasonic frequency of 2 ~ 10MHz, it can be propagated in the human body, and after encountering different tissues can reflect part of back. Based on this physical property, scientists have developed various ultrasound instruments. Ultrasound waves are generated and emitted by a probe, and after entering the human body, according to the differences in the acoustic properties of human organs and tissues, some of the ultrasound waves are reflected back, and then accepted by the probe and processed by a computer, and displayed and traced out in the form of waveforms, curves or images.
