Popularno znanstveno znanje oultrazvuk
Whether it's a health check-up or a visit to the hospital, doctors always ask patients to have an ultrasound. Most people's understanding of ultrasound is that pregnant women need B-ultrasound, but in fact, ultrasound is not only used for pregnant women to check the fetus, this is only a small part of the application of ultrasound in clinical medicine. But what exactly is ultrasound? How does it examine the human body?
Ultrasound, that is, ultrasound, is a mechanical wave. The frequency of sound waves that can be heard by the human ear is between 20 and 20 000 Hz. When the vibration frequency of sound waves is greater than 20 000 Hz or less than 20 Hz, we cannot hear them. Therefore, we call sound waves with frequencies higher than 20 000 Hz "ultrasonic". Ultrasonic has the characteristics of good directionality, strong penetrating ability, easy to obtain relatively concentrated sound energy, long distance in water, etc. It can be used for distance measurement, speed measurement, cleaning, welding, gravel, etc., in medicine, military, industry, agriculture widely used.
Ultrazvučna frekvencija koja se obično koristi za medicinsku dijagnozu je 210MHz. Može putovati tijelom i reflektirati dio natrag nakon udara u različita tkiva. Prema ovom fizičkom svojstvu znanstvenici su razvili različite ultrazvučne instrumente. Ultrazvučni val generira i emitira sonda. Nakon ulaska u ljudsko tijelo, dio ultrazvučnog vala se reflektira natrag prema razlici u akustičkim svojstvima ljudskih organa i tkiva, a zatim ga prima sonda i obrađuje računalo, prikazuje i prati u obliku valnih oblika, krivulja ili slike. , Ultrazvuk je dijagnostička metoda kojom liječnik ultrazvukom može razlikovati fiziološka i patološka stanja prema karakteristikama slike.
