Ultrasound

Ultrasound is a cyclic sound pressure wave with a frequency greater than the upper limit of the human hearing range. Ultrasound is thus not separated from "normal" (audible) sound based on differences in physical properties, only the fact that humans cannot hear it. Although this limit varies from person to person, it 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. Ultrasonic imaging (sonography) is used in human and veterinary medicine. In non-destructive testing of products and structures, ultrasound is used to detect invisible flaws. Industrially, ultrasound is used for cleaning and for mixing, and to accelerate chemical processes. Organisms such as bats and porpoises use ultrasound for locating prey and obstacles.

Ultrasonics is the application of ultrasound. Ultrasound can be used for imaging, detection, measurement, and cleaning. At higher power levels ultrasonics are useful for changing the chemical properties of substances.

Read more about Ultrasound:  History, Imaging, Acoustic Microsopy, Processing and Power, Other Uses, Nonlinear Propagation Effects, Safety

Other articles related to "ultrasound":

Cirrhosis - Diagnosis - Imaging
... Ultrasound is routinely used in the evaluation of cirrhosis, where it may show a small and nodular liver in advanced cirrhosis along with increased echogenicity with irregular appearing areas ... Ultrasound may also screen for hepatocellular carcinoma, portal hypertension and Budd-Chiari syndrome (by assessing flow in the hepatic vein) ... The FibroScan produces an ultrasound image of the liver (from 20–80 mm) along with a pressure reading (in kPa) ...
Acoustic Microscopy - Behavior of Ultrasound in Materials
... Ultrasound is broadly defined as any sound having a frequency above 20 kHz, which is approximately the highest frequency that can be detected by the human ear ... However, the acoustic microscopes emit ultrasound ranging from 5 MHz to beyond 400 MHz so that micrometre size resolution can be achieved ... The ultrasound that penetrates a sample may be scattered, absorbed or reflected by the internal features or the material itself ...
Ultrasound - Safety
... Occupational exposure to ultrasound in excess of 120 dB may lead to hearing loss ... This report recommended an exposure limit for the general public to airborne ultrasound sound pressure levels (SPL) of 70 dB (at 20 kHz), and 100 dB (at 25 kHz and above) ...
Acoustic Targeted Drug Delivery - How ATDD Works
... Focused ultrasound similar to High intensity focused ultrasound, but at much lower powers is applied to tissues in conjunction with the local application of pharmological agent ... The ultrasound source (or transducer) is pulsed on and off, and moved in a defined pattern to sonicate the tissue of interest ... The pulsing of the ultrasound serves two purposes 1 ...
American Institute Of Ultrasound In Medicine
... The American Institute of Ultrasound in Medicine is a multidisciplinary association dedicated to advancing the use of ultrasound in medicine through professional and public education ... sonographers, physicians, scientists, engineers, other health care providers, manufacturers of ultrasound equipment, and students ... by committees and a Council on Sections, representing many ultrasound specialties ...