Ultrasound

Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Ultrasound is a 'normal' sound in its physical properties, except that humans cannot hear it. This limit changes from person to person and is approximately 20 kilohertz (20,000 hertz) in healthy, young adults. Ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.

Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging (sonography) is often used in medicine. In the nondestructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning, mixing, and to accelerate chemical processes. Animals such as bats and porpoises use ultrasound for locating prey and obstacles. Scientist are also studying ultrasound using graphene diaphragms as a method of communication.

Human medicine
Ultrasound sonography is a method that uses sound waves to produce pictures of the inside of the body. This method helps diagnose the causes of pain, swelling and infection in the body’s internal organs, also to examine a baby in pregnant women and the brain and hips in infants. It’s also used to help guide biopsies, diagnose heart conditions, and assess damage after a heart attack. Ultrasound is noninvasive method, and does not use ionizing radiation.

An instrument called a transducer emits high-frequency sound, unable to hear to human ears, and then records the echoes as the sound waves bounce back to determine the size, shape, and consistency of soft tissues and organs.

These informations are produced on a computer screen in a real time. Ultrasound technicians, or sonographers, have special training in how to perform the test. Then a radiologist will interpret the ultrasound images. This technology can help diagnose and treat certain conditions.

Physiotherapy
Ultrasound has been used since the 1940s by physical and occupational therapists for treating connective tissue: ligaments, tendons, and fascia (and also scar tissue).Conditions for which ultrasound may be used for treatment include the follow examples: ligament sprains, muscle strains, tendonitis, joint inflammation, plantar fasciitis, metatarsalgia, facet irritation, impingement syndrome, bursitis, rheumatoid arthritis, osteoarthritis, and scar tissue adhesion.

Biomedical applications

Ultrasound also has therapeutic applications, which can be highly beneficial when used with dosage precautions relatively high power ultrasound can break up stony deposits or tissue, accelerate the effect of drugs in a targeted area, assist in the measurement of the elastic properties of tissue, and can be used to sort cells or small particles for research.

How ultrasound works in 60 sec: https://www.youtube.com/watch?v=I1Bdp2tMFsY

Ultrasonic cleaning
Ultrasonic cleaners, sometimes mistakenly called supersonic cleaners, are used at frequencies from 20 to 40 kHz for jewellery, lenses and other optical parts, watches, dental instruments, surgical instruments, diving regulators and industrial parts. An ultrasonic cleaner works mostly by energy released from the collapse of millions of microscopic cavitations near the dirty surface. The bubbles made by cavitation collapse forming tiny jets directed at the surface.

Links
https://www.webmd.com/a-to-z-guides/what-is-an-ultrasound

https://www.radiologyinfo.org/en/info.cfm?pg=genus

http://www.wikiskripta.eu/w/Ultrazvuk

https://www.medicinenet.com/ultrasound/article.htm

http://www.ultrazvuk-simonovsky.cz/sonography_ultrasound.html