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Encyclopedia > Ultrasound

Ultrasound is cyclic sound pressure with a frequency greater than the upper limit of human hearing. Although this limit varies from person to person, it is approximately 20 kilohertz (20,000 hertz) in healthy, young adults and thus, 20 kHz serves as a useful lower limit in describing ultrasound. The production of ultrasound is used in many different fields, typically to penetrate a medium and measure the reflection signature or supply focused energy. The reflection signature can reveal details about the inner structure of the medium. The most well known application of this technique is its use in sonography to produce pictures of fetuses in the human womb. There are a vast number of other applications as well. Look up ultrasound in Wiktionary, the free dictionary. ... This article is about audible acoustic waves. ... For other uses, see Frequency (disambiguation). ... This article is about modern humans. ... Hearing (or audition) is one of the traditional five senses, and refers to the ability to detect sound. ... This article is about the SI unit of frequency. ...

Approximate frequency ranges corresponding to ultrasound, with rough guide of some applications
Approximate frequency ranges corresponding to ultrasound, with rough guide of some applications
A fetus in its mother's womb, viewed in a sonogram (brightness scan)
A fetus in its mother's womb, viewed in a sonogram (brightness scan)


Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... ImageMetadata File history File links Baby_in_ultrasound. ... ImageMetadata File history File links Baby_in_ultrasound. ...

Ability to hear ultrasound

The upper frequency limit in humans (approximately 20 kHz) is caused by the middle ear, which acts as a low-pass filter. Ultrasonic hearing can occur if ultrasound is fed directly into the skull bone and reaches the cochlea without passing through the middle ear. Carefully-designed scientific studies have been performed and confirmed what they call the hypersonic effect - that even without consciously hearing it, high-frequency sound can have a measurable effect on the mind. The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. ... A low-pass filter is a filter that passes low frequencies but attenuates (or reduces) frequencies higher than the cutoff frequency. ... Ultrasonic hearing is a recognised auditory effect which allows humans to perceive sounds of a much higher frequency than would ordinarily be audible using the physical inner ear, usually by stimulation of the base of the cochlea through bone induction. ... The cochlea is the auditory portion of the inner ear. ... The hypersonic effect is a term coined to describe the phenomenon reported in some scientific studies, which demonstrate that although humans cannot consciously hear sounds at very high frequency (above around 20 kHz), the presence or absence of those frequencies has a measurable effect on their psychological reaction. ...

It is a fact in psychoacoustics that children can hear some high-pitched sounds that older adults cannot hear, because in humans the upper limit pitch of hearing tends to become lower with age.[1] [2][3] A cell phone company has used this to create ring signals supposedly only able to be heard by younger humans[4]; but many older people claim to be able to hear it, which is likely given the considerable variation of age-related deterioration in the upper hearing threshold. Psychoacoustics is the study of subjective human perception of sounds. ... Motorola T2288 mobile phone A mobile phone is a portable electronic device which behaves as a normal telephone whilst being able to move over a wide area (compare cordless phone which acts as a telephone only within a limited range). ...

Some animals – such as dogs, cats, dolphins, bats, and mice – have an upper frequency limit that is greater than that of the human ear and thus can hear ultrasound. Trinomial name Canis lupus familiaris The dog (Canis lupus familiaris) is a domestic subspecies of the wolf, a mammal of the Canidae family of the order Carnivora. ... Cats may refer to: Felines, members of the animal family Felidae The domesticated animal, cat The musical, yeah right, I bet that this was really dumb. ... This article is about the dolphin mammal. ... “Chiroptera” redirects here. ... This article is about the rodent. ... For other uses, see Ear (disambiguation). ...

Diagnostic sonography

Sonogram of a fetus at 14 weeks (Profile)
Sonogram of a fetus at 14 weeks (Profile)
A fetus, aged 29 weeks, in a "3D ultrasound"
A fetus, aged 29 weeks, in a "3D ultrasound"

Medical sonography (ultrasonography) is an ultrasound-based diagnostic medical imaging technique used to visualize muscles, tendons, and many internal organs, their size, structure and any pathological lesions with real time tomographic images. It is also used to visualize a fetus during routine and emergency prenatal care. Ultrasound scans are performed by medical health care professionals called sonographers. Obstetric sonography is commonly used during pregnancy. Ultrasound has been used to image the human body for at least 50 years. It is one of the most widely used diagnostic tools in modern medicine. The technology is relatively inexpensive and portable, especially when compared with modalities such as magnetic resonance imaging (MRI) and computed tomography (CT). As currently applied in the medical environment, ultrasound poses no known risks to the patient.[5] Sonography is generally described as a "safe test" because it does not use ionizing radiation, which imposes hazards, such as cancer production and chromosome breakage. However, ultrasonic energy has two potential physiological effects: it enhances inflammatory response; and it can heat soft tissue.[6] Ultrasound energy produces a mechanical pressure wave through soft tissue. This pressure wave may cause microscopic bubbles in living tissues, and distortion of the cell membrane, influencing ion fluxes and intracellular activity. When ultrasound enters the body, it causes molecular friction and heats the tissues slightly. This effect is very minor as normal tissue perfusion dissipates heat. With high intensity, it can also cause small pockets of gas in body fluids or tissues to expand and contract/collapse in a phenomenon called cavitation (this is not known to occur at diagnostic power levels used by modern diagnostic ultrasound units). The long-term effects of tissue heating and cavitation are not known.[7] There are several studies that indicate the harmful side effects on animal fetuses associated with the use of sonography on pregnant mammals. A noteworthy study in 2006 suggests exposure to ultrasound can affect fetal brain development in mice. This misplacement of brain cells during their development is linked to disorders ranging "from mental retardation and childhood epilepsy to developmental dyslexia, autism spectrum disorders and schizophrenia, the researchers said. However, this effect was only detectable after 30 minutes of continuous scanning. [8] A typical fetal scan, including evaluation for fetal malformations, typically takes 10-30 minutes.[9] There is no link made yet between the test results on animals, such as mice, and the possible outcome to humans. Widespread clinical use of diagnostic ultrasound testing on humans has not been done for ethical reasons. The possibility exists that biological effects may be identified in the future, currently most doctors feel that based on available information the benefits to patients outweigh the risks.[10] Obstetric ultrasound can be used to identify many conditions that would be harmful to the mother and the baby. For this reason many health care professionals consider that the risk of leaving these conditions undiagnosed is much greater than the very small risk, if any, associated with undergoing the scan. According to Cochrane review, routine ultrasound in early pregnancy (less than 24 weeks) appears to enable better gestational age assessment, earlier detection of multiple pregnancies and earlier detection of clinically unsuspected fetal malformation at a time when termination of pregnancy is possible.[11] Image File history File links Embryo_at_14_weeks_profile. ... Image File history File links Embryo_at_14_weeks_profile. ... Image File history File links 3dultrasound. ... Image File history File links 3dultrasound. ... 4D Ultrasound (also known as 3D/4D Ultrasound) is the most advanced technology used by sonographers during pregnancy to evaluate the unborn fetus. ... Sonography redirects here. ... Medical imaging designates the ensemble of techniques and processes used to create images of the human body (or parts thereof) for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and function). ... Skin lesions caused by Chickenpox A lesion is any abnormal tissue found on or in an organism, usually damaged by disease or trauma. ... A doctor performs a prenatal exam. ... Sonographers are medical professionals who operate ultrasonic imaging devices to produce diagnostic images and scans, videos, or 3D volumes of anatomy and diagnostic data. ... Obstetric sonogram of a fetus at 16 weeks. ... This article is about human pregnancy in biological females. ... MRI redirects here. ... negron305 Cat scan redirects here. ... Night writing was a system of code that used symbols of twelve dots (2 wide and 6 high) designed by Charles Barbier in response to Napoleons demand for a code that soldiers could use to communicate silently and without light at night. ...

Sonography is used routinely in obstetric appointments during pregnancy, but the FDA discourages its use for non-medical purposes such as fetal keepsake videos and photos, even though it is the same technology used in hospitals. Night writing was a system of code that used symbols of twelve dots (2 wide and 6 high) designed by Charles Barbier in response to Napoleons demand for a code that soldiers could use to communicate silently and without light at night. ...

Obstetric ultrasound is primarily used to:

  • Date the pregnancy (gestational age)
  • Confirm fetal viability
  • Determine location of fetus, intrauterine vs ectopic
  • Check the location of the placenta in relation to the cervix
  • Check for the number of fetuses (multiple pregnancy)
  • Check for major physical abnormalities.
  • Assess fetal growth (for evidence of intrauterine growth restriction (IUGR))
  • Check for fetal movement and heartbeat.
  • Determine the sex of the baby

Unfortunately, results are occasionally wrong,[citations needed] producing a false positive (the Cochrane Collaboration is a relevant effort to improve the reliability of health care trials). False detection may result in patients being warned of birth defects when no such defect exists. Sex determination is only accurate after 12 weeks gestation [Ultrasound in Obstetrics and Gynecology 1999]. When balancing risk and reward, there are recommendations to avoid the use of routine ultrasound for low risk pregnancies [ACOG]. In many countries ultrasound is used routinely in the management of all pregnancies. Gestational age is age of a fetus (or newborn infant) from presumed conception. ... For other uses, see Fetus (disambiguation). ... Ectopia is a displacement or malposition of an organ of the body. ... Identical triplet brothers Quadruplet, quintuplet, etc. ... Intrauterine growth retardation or Intrauterine growth restriction (IUGR) refers to the condition during pregnancy where a fetus is considered to be too small for its gestational age (generally in the 10th percentile). ... Intrauterine growth retardation or Intrauterine growth restriction (IUGR) refers to the condition during pregnancy where a fetus is considered to be too small for its gestational age (generally in the 10th percentile). ... The Cochrane Collaboration developed in response to Archie Cochranes call for systematic, up-to-date reviews (currently known as systematic reviews) of all relevant randomized clinical trials of health care. ...

According to the European Committee of Medical Ultrasound Safety (ECMUS) "Ultrasonic examinations should only be performed by competent personnel who are trained and updated in safety matters. Ultrasound produces heating, pressure changes and mechanical disturbances in tissue. Diagnostic levels of ultrasound can produce temperature rises that are hazardous to sensitive organs and the embryo/fetus. Biological effects of non-thermal origin have been reported in animals but, to date, no such effects have been demonstrated in humans, except when a microbubble contrast agent is present."[12]

A study on rodent fetus brains that are exposed to ultrasound showed signs of damage. Speculation on human fetuses can be in a range of no significant complications to a variety of mental and brain disorders. The study shows that rodent brain cells failed to grow to their proper position and remained scattered in incorrect parts of the brain. The conditions of this experiment are different from typical fetal scanning because of the long dwell times. [National Institute of Neurological Disorders; Proceedings of the National Academy of Sciences]. Care should be taken to use low power settings and avoid pulsed wave scanning of the fetal brain unless specifically indicated in high risk pregnancies.

It should be noted that obstetrics is not the only use of ultrasound. Soft tissue imaging of many other parts of the body is conducted with ultrasound. Other scans routinely conducted are cardiac, renal, liver and gallbladder (hepatic). Other common applications include musculo-skeletal imaging of muscles, ligaments and tendons, ophthalmic ultrasound (eye) scans and superficial structures such as testicle, thyroid, salivary glands and lymph nodes. Because of the real time nature of ultrasound, it is often used to guide interventional procedures such as fine needle aspiration FNA or biopsy of masses for cytology or histology testing in the breast, thyroid, liver, kidney, lymph nodes, muscles and joints. The liver is an organ in vertebrates including humans. ... Ophthalmology is the branch of medicine which deals with the diseases of the eye and their treatment. ... Look up testes in Wiktionary, the free dictionary. ... The salivary glands produce saliva, which keeps the mouth and other parts of the digestive system moist. ... Lymph nodes are components of the lymphatic system. ... It has been suggested that Real-time computing be merged into this article or section. ... Needle aspiration biopsy (NAB), also known as fine needle aspiration cytology (FNAC), fine needle aspiration biopsy (FNAB) and fine needle aspiration (FNA), is a diagnostic procedure sometimes used to investigate superficial (just under the skin) lumps or masses. ... Brain biopsy A biopsy (in Greek: bios = life and opsy = look/appearance) is a medical test involving the removal of cells or tissues for examination. ... Cytology (also known as Cell biology) is the scientific study of cells. ... A thin section of lung tissue stained with hematoxylin and eosin. ...

Ultrasound scanners using pulsed wave and colour Doppler are used to visualize arteries and veins. This is a disambiguation page — a navigational aid which lists other pages that might otherwise share the same title. ...

Figures released for the period 2005-2006 by UK Government (Department of Health) show that non-obstetric ultrasound examinations contributed to more than 65% of the total number of ultrasound scans conducted.

Biomedical ultrasonic applications

Ultrasound also has therapeutic applications, which can be highly beneficial when used with dosage precautions:[13]

  • According to RadiologyInfo [14], ultrasounds are useful in the detection of Pelvic abnormalities and can involve techniques known as abdominal (transabdominal) ultrasound, vaginal (transvaginal or endovaginal) ultrasound in women, and also rectal (transrectal) ultrasound in men.
  • Treating benign and malignant tumors and other disorders, via a process known as Focused Ultrasound Surgery (FUS) or HIFU, High Intensity Focused Ultrasound. These procedures generally use lower frequencies than medical diagnostic ultrasound (from 250 kHz to 2000 kHz), but significantly higher time-averaged intensities. The treatment is often guided by MRI, as in Magnetic Resonance guided Focused Ultrasound.
  • Delivering chemotherapy to brain cancer cells and various drugs to other tissues, via a process known as Acoustic Targeted Drug Delivery [15] These procedures generally use high frequency ultrasound (from 1 MHz to 10 MHz) and a range of intensities from 0-20 watts/cm2. The acoustic energy is focused on the tissue of interest to agitate its matrix and make it more permiable to therapeutic drugs.[16][17]
    Enhanced drug uptake using Acoustic Targeted Drug Delivery
    Enhanced drug uptake using Acoustic Targeted Drug Delivery
  • Therapeutic ultrasound, a technique that uses more powerful ultrasound sources to generate local heating in biological tissue, e.g. in occupational therapy, physical therapy, Athletic Training and cancer treatment.
  • Cleaning teeth in dental hygiene.
  • Focused ultrasound sources may be used for cataract treatment by phacoemulsification.
  • Additional physiological effects of low-intensity ultrasound have recently been discovered, e.g. the ability to stimulate bone-growth and its potential to disrupt the blood-brain barrier for drug delivery.
  • Ultrasound is used in UAL (ultrasound-assisted lipectomy), or liposuction.
  • Doppler ultrasound is being tested for use in aiding tissue plasminogen activator treatment in stroke sufferers. This procedure is called Ultrasound-Enhanced Systemic Thrombolysis.
  • Low intensity pulsed ultrasound is used for therapeutic tooth and bone regeneration.
  • Ultrasound can also be used for elastography. This can be useful in medical diagnoses, as elasticity can discern healthy from unhealthy tissue for specific organs/growths. In some cases unhealthy tissue may have a lower system Q, meaning that the system acts more like a large heavy spring as compared to higher values of system Q (healthy tissue) that respond to higher forcing frequencies. Ultrasonic elastography is different from conventional ultrasound, as a transceiver (pair) and a transmitter are used instead of only a transceiver. One transducer (a single element {or array of elements} acts as both the transmitter and receiver to image the region of interest over time. The extra transmitter is a very low frequency transmitter, and perturbs the system so the unhealthy tissue oscillates at a low frequency and the healthy tissue does not. The transceiver, which operates at a high frequency (typically MHz) then measures the displacement of the unhealthy tissue (oscillating at a much lower frequency). The movement of the slowly oscillating tissue is used to determine the elasticity of the material, which can then be used to distinguish healthy tissue from the unhealthy tissue.
  • Ultrasound has been shown to act synergistically with antibiotics in bacterial cell killing.[18]
  • Ultrasound has been postulated to allow thicker eukaryotic cell tissue cultures by promoting nutrient penetration.Scientific Article
  • Ultrasound in the low MHz range in the form of standing waves is an emerging tool for contactless separation, concentration and manipulation of microparticles and biological cells. The basis is the acoustic radiation force, a non-linear effect which causes particles to be attracted to either the nodes or anti-nodes of the standing wave depending on the acoustic contrast factor, which is a function of the sound velocities and densities of the particle and of the medium in which the particle is immersed.

The abdomen (from the Latin word meaning belly) is the part of the body between the pelvis and the thorax. ... Human female internal reproductive anatomy The vagina (from the Latin for sheath or scabbard ) is the tubular tract leading from the uterus to the exterior of the body in female mammals, or to the cloaca in female birds and some reptiles. ... The posterior aspect of the rectum exposed by removing the lower part of the sacrum and the coccyx. ... HIFU, or high intensity focused ultrasound, also referred to as Focused Ultrasound Surgery (FUS), is a term used describe a minimally or non-invasive method to deposit acoustic energy into tissue. ... The mri are a fictional alien species in the Faded Sun Trilogy of C.J. Cherryh. ... Magnetic Resonance guided Focused Ultrasound, often shortened to MRgFUS, uses magnetic resonance imaging (MRI) to identify tumors or fibroids in the body, and focused high-intensity ultrasound to destroy them. ... Therapeutic ultrasound is a technique that uses high-frequency sound waves (ultrasound) to speed healing in injured joint or muscle tissue. ... Occupational therapy refers to the use of meaningful occupation to assist people who have difficulty in achieving healthy and balanced life; and to enable an inclusive society so that all people can participate to their potential in daily occupations of life. ... Physical therapy (or physiotherapy[1]) is the provision of services to people and populations to develop, maintain and restore maximum movement and functional ability throughout the lifespan. ... Experimental cancer treatments are medical therapies intended or claimed to treat cancer (see also tumor) by improving on, supplementing or replacing conventional methods (surgery, chemotherapy, radiation, and immunotherapy). ... A Dental hygienist attends to a patient A dental hygienist is a licensed dental auxiliary who specializes in preventive dental care, typically but not limited to focusing on techniques in oral hygiene . ... Human eye cross-sectional view, showing position of human lens. ... Phacoemulsification: Cataract surgery, by a temporal approach, using a phacoemulsification probe (in right hand) and chopper(in left hand), being done under operating microscope at a Navy medical center Phacoemulsification refers to modern cataract surgery in which the eyes internal lens is emulsified with an ultrasonic handpiece, and aspirated... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... United Airlines Boeing 777 taking off at Schiphol, Amsterdam. ... Liposuction, also known as lipoplasty (fat modeling), liposculpture or suction lipectomy (suction-assisted fat removal) is a cosmetic surgery operation which removes fat from many different sites on the human body. ... Liposuction, also known as lipoplasty (fat modeling), liposculpture or suction lipectomy (suction-assisted fat removal) is a cosmetic surgery operation that removes fat from many different sites on the human body. ... In blood coagulation, tissue plasminogen activator (tPA) is an enzyme (EC 3. ... For other uses, see Stroke (disambiguation). ... Ultrasound-Enhanced Systemic Thrombolysis is a medical technology. ... Low intensity pulsed ultrasound (LIPUS) is a medical technology. ... Elastography is an emerging method in which stiffness or strain images of soft tissue are used to detect tumors. ... This article or section does not cite any references or sources. ... Vibration and standing waves in a string, The fundamental and the first 6 overtones A standing wave, also known as a stationary wave, is a wave that remains in a constant position. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... To do: 20th century mathematics chaos theory, fractals Lyapunov stability and non-linear control systems non-linear video editing See also: Aleksandr Mikhailovich Lyapunov Dynamical system External links http://www. ... A standing wave. ... A standing wave. ... The acoustic contrast factor is a number used to describe the relationship between the densities and the sound velocities (or, equivalently because of the form of the expression, the densities and compressibilities) of two media. ... This article is about functions in mathematics. ... The speed of sound varies depending on the medium through which the sound waves pass. ... For other uses, see Density (disambiguation). ...

Industrial ultrasound

Main article: Ultrasonic testing
Non-destructive testing of a swing shaft showing spline cracking
Non-destructive testing of a swing shaft showing spline cracking

Ultrasonic testing is a type of nondestructive testing commonly used to find flaws in materials and to measure the thickness of objects. Frequencies of 2 to 10 MHz are common but for special purposes other frequencies are used. Inspection may be manual or automated and is an essential part of modern manufacturing processes. Most metals can be inspected as well as plastics and aerospace composites. Lower frequency ultrasound (50 kHz to 500 kHz) can also be used to inspect less dense materials such as wood, concrete and cement. An example of Ultrasonic Testing (UT) on blade roots of a V2500 IAE aircraft engine. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Spline can refer to: Spline, a mechanical device used for drawing curves. ... An example of Ultrasonic Testing (UT) on blade roots of a V2500 IAE aircraft engine. ... // Nondestructive testing (also called NDT, nondestructive evaluation, NDE, and nondestructive inspection, NDI) is testing that does not destroy the test object. ... This article is about metallic materials. ... The term plastics covers a range of synthetic or semi-synthetic organic condensation or polymerization products that can be molded or extruded into objects or films or fibers. ... Look up aerospace in Wiktionary, the free dictionary. ... Composite materials (or composites for short) are engineering materials made from two or more components. ... For other uses, see Wood (disambiguation). ... This article is about the construction material. ... For other uses, see Cement (disambiguation). ...

Ultrasound can also be used for heat transfer in liquids.[19]

Researchers recently employed ultrasound in dry corn milling plant to enhance ethanol production.[20]

Ultrasonic cleaning

Ultrasonic cleaners, sometimes mistakenly called supersonic cleaners, are used at frequencies from 20-40 kHz for jewellery, lenses and other optical parts, watches, dental instruments, surgical instruments 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. Home ultrasonic cleaners are available and cost about US $60 or more. Ultrasonic cleaners, sometimes mistakenly called supersonic cleaners, are cleaning devices that use ultrasounds (usually from 20-40 kHz) to clean delicate items. ... A United States Navy F/A-18E/F Super Hornet in transonic flight. ... This article is about the SI unit of frequency. ... For the Korean music group, see Jewelry (group). ... This article is about the optical device. ... For other uses, see Watch (disambiguation). ... This article is about the dental profession. ... Surgeon excising an arrow from a wounded soldier, Stele from Herculaneum, Rome, 1 BC A surgical instrument is a specially designed tool or device for performing specific actions of carrying out desired effects during a surgery or operation, such as modifying biological tissue, or to provide access or viewing it. ... Cavitating propeller model in a water tunnel experiment High speed jet of fluid impact on a fixed surface. ... Cavitating propeller model in a water tunnel experiment High speed jet of fluid impact on a fixed surface. ...

Ultrasonic humidifier

The ultrasonic humidifier, one type of nebulizer (a device that creates a very fine spray), is a popular type of humidifier. It works by vibrating a metal plate at ultrasonic frequencies to nebulize (sometimes incorrectly called "atomize") the water. Because the water is not heated for evaporation, it produces a cool mist. The ultrasonic pressure waves nebulize not only the water but also materials in the water including calcium, other minerals, viruses, fungi, bacteria[21], and other impurities. Illness caused by impurities that reside in a humidifier's reservoir fall under the heading of "Humidifier Fever". A humidifier is a household appliance that increases humidity (moisture) in a single room or in the entire home. ... A nebulizer with an attached inhaling apparatus In medicine, a nebulizer is a device used to administer medication to people in forms of a liquid mist to the airways. ...

Ultrasound Identification (USID)

Ultrasound Identification (USID) is a Real Time Locating System (RTLS) or Indoor Positioning System (IPS) technology used to automatically track and identify the location of objects in real time using simple, inexpensive nodes (badges/tags) attached to or embedded in objects and devices, which then transmit an ultrasound signal to communicate their location to microphone sensors. The RTLS capability is somewhere referred as Real Time Location Systems. ...

Ultrasound and animals


Bats use a variety of ultrasonic ranging (echolocation) techniques to detect their prey. They can detect frequencies as high as 100 kHz, although there is some disagreement on the upper limit.[22] “Chiroptera” redirects here. ... Echolocation, also called Biosonar, is the biological sonar used by several mammals such as bats (although not all species), dolphins and whales (though not baleen whales). ...


Dogs can hear sound at higher frequencies than humans can. A dog whistle exploits this by emitting a high frequency sound to call to a dog. Many dog whistles emit sound in the upper audible range, but some, such as the silent whistle, emit ultrasound at a frequency in the range of 18 kHz to 22 kHz. Trinomial name Canis lupus familiaris The dog (Canis lupus familiaris) is a domestic subspecies of the wolf, a mammal of the Canidae family of the order Carnivora. ... A dog whistle (also known as silent whistle or Galtons whistle) is a type of whistle used in the training of dogs and cats. ...

Dolphins and whales

It is well known that some whales can hear ultrasound and have their own natural sonar system. Some whales use the ultrasound as a hunting tool (for both detection of prey and as an attack). This article is about underwater sound propagation. ...


Several types of fish can detect ultrasound. Of the order Clupeiformes, members of the subfamily Alosinae (shad), have been shown to be able to detect sounds up to 180 kHz, while the other subfamilies (e.g. herrings) can hear only up to 4 kHz.[23] Families Denticipitidae (denticle herring) Engraulidae (anchovies) Pristigasteridae (pristigasterids) Chirocentridae (wolf herring) Clupeidae (herrings) Clupeiformes is the order of ray-finned fish that includes the herring family, Clupeidae, and the anchovy family, Engraulidae. ... For the Canadian hip hop musician, see Shad (rapper). ... Species Clupea alba Clupea bentincki Clupea caspiopontica Clupea chrysotaenia Clupea elongata Clupea halec Clupea harengus Clupea inermis Clupea leachii Clupea lineolata Clupea minima Clupea mirabilis Clupea pallasii Clupea sardinacaroli Clupea sulcata Herrings are small, oily fish of the genus Clupea found in the shallow, temperate waters of the North Atlantic...


There is evidence that ultrasound in the range emitted by bats causes flying moths to make evasive manoeuvres because bats eat moths. Ultrasonic frequencies trigger a reflex action in the noctuid moth that cause it to drop a few inches in its flight to evade attack. [1] “Chiroptera” redirects here. ... For other uses, see Moths. ... Diversity 4,200 genera 35,000 species Type Species Noctua pronuba (Large Yellow Underwing) Subfamilies Acontiinae Acronictinae Aganainae Agaristinae Amphipyrinae Amphipyrinae Bagisarinae Bryophilinae Calpinae Catocalinae Cocytiinae Condicinae Cuculliinae Dilobinae Eucocytiinae Eustrotiinae Euteliinae Glottulinae Hadeninae Heliothinae Herminiinae Hypeninae Ipimorphinae Noctuinae Plusiinae Psaphidinae Raphiinae Stictopterinae Stiriinae Strepsimaninae Ufeinae The Noctuidae or Owlets...


Ultrasound generator/speaker systems are sold with claims that they frighten away rodents and insects, but there is no scientific evidence that the devices work. Laboratory tests conducted by Kansas State University did show positive results for products from specific manufacturers. Controlled tests on some of the systems have shown that rodents quickly learn that the speakers are harmless. Suborders Sciuromorpha Castorimorpha Myomorpha Anomaluromorpha Hystricomorpha Rodentia is an order of mammals also known as rodents, characterised by two continuously-growing incisors in the upper and lower jaws which must be kept short by gnawing. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera...


Main article: Sonochemistry

Power ultrasound in the 20-100 kHz range is used in chemistry. The ultrasound does not interact directly with molecules to induce the chemical change, as its typical wavelength (in the millimeter range) is too long compared to the molecules. Instead: In chemistry, the study of sonochemistry is concerned with understanding the effect of sonic waves and wave properties on chemical systems. ... For other uses, see Chemistry (disambiguation). ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ...

  • It causes cavitation which causes local extremes of temperature and pressure in the liquid where the reaction happens.
  • It breaks up solids and removes passivating layers of inert material to give a larger surface area for the reaction to occur over.

Both of these make the reaction faster. Cavitating propeller model in a water tunnel experiment High speed jet of fluid impact on a fixed surface. ... Passivation is the process of making a material passive in relation to another material prior to using the materials together. ... In English, to be inert is to be in a state of doing little or nothing. ... Area is the measure of how much exposed area any two dimensional object has. ...

Ultrasonic disintegration

Some sorts of ultrasound can disintegrate biological cells including bacteria. This has uses in biological science and in killing bacteria in sewage. High power ultrasound at frequency of around 20 kHz produces cavitation that facilitates particle disintegration. Dr. Samir Khanal of Iowa State University employed high power ultrasound to disintegrate corn slurry to enhance liquefaction and saccharification for higher ethanol yield in dry corn milling plants. Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... For the song by Girls Aloud see Biology (song) Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: Βιολογία - βίος, bio, life; and λόγος, logos, speech lit. ... Sewage is the mainly liquid waste containing some solids produced by humans which typically consists of washing water, faeces, urine, laundry waste and other material which goes down drains and toilets from households and industry. ...

See examples:-

Ultrasonic range finding

Main article: sonar

A common use of ultrasound is in range finding; this use is also called SONAR, (sound navigation and ranging). This works similarly to RADAR (radio detection and ranging): An ultrasonic pulse is generated in a particular direction. If there is an object in the path of this pulse, part or all of the pulse will be reflected back to the transmitter as an echo and can be detected through the receiver path. By measuring the difference in time between the pulse being transmitted and the echo being received, it is possible to determine how far away the object is. This article is about underwater sound propagation. ... A rangefinder is a device that measures distance from the observer to a target, for the purposes of surveying, determining focus in photography, or accurately aiming a weapon. ... This article is about underwater sound propagation. ... For other uses, see Radar (disambiguation). ... In audio signal processing and acoustics, an echo (plural echoes) is a reflection of sound, arriving at the listener some time after the direct sound. ...

The measured travel time of SONAR pulses in water is strongly dependent on the temperature and the salinity of the water. Ultrasonic ranging is also applied for measurement in air and for short distances. Such method is capable for easily and rapidly measuring the layout of rooms.

Although range finding underwater is performed at both sub-audible and audible frequencies for great distances (1 to several ten kilometers), ultrasonic range finding is used when distances are shorter and the accuracy of the distance measurement is desired to be finer. Ultrasonic measurements may be limited through barrier layers with large salinity, temperature or vortex differentials. Ranging in water varies from about hundreds to thousands of meters, but can be performed with centimeters to meters accuracy.

Other uses

Ultrasound when applied in specific configurations can produce short bursts of light in an exotic phenomenon known as sonoluminescence. This phenomenon is being investigated partly because of the possibility of bubble fusion (a nuclear fusion reaction hypothesized to occur during sonoluminescence). Long exposure image of multi-bubble sonoluminescence created by a high intensity ultrasonic horn immersed in a beaker of liquid. ... Bubble fusion or sonofusion is the common name for a nuclear fusion reaction hypothesized to occur during sonoluminescence, an extreme form of acoustic cavitation; officially, this reaction is termed acoustic inertial confinement fusion (AICF) since the inertia of the collapsing bubble wall confines the energy causing a rise in temperature. ... The deuterium-tritium (D-T) fusion reaction is considered the most promising for producing sustainable fusion power. ...

Recently researchers at the University of Alberta in Canada have successfully used ultrasound to regenerate dental material[citation needed]. The University of Alberta (U of A) is a public coeducational research university located in Edmonton, Alberta, Canada. ...

Ultrasound is used when characterizing particulates through the technique of ultrasound attenuation spectroscopy or by observing electroacoustic phenomena. Ultrasound attenuation spectroscopy is a method for characterizing properties of fluids and dispersed particles. ... Electroacoustic phenomena arises when ultrasound propagates through a fluid containing ions. ...

In rheology, an acoustic rheometer relies on the principle of ultrasound. In fluid mechanics, fluid flow can be measured using an ultrasound flow meter. Rheology is the study of the deformation and flow of matter under the influence of an applied stress. ... This article is about instrument for studying extensional rheology. ... This box:      Fluid mechanics is the study of how fluids move and the forces on them. ... Ultrasonic flowmeters come in three different types: Transmission (contrapropagating transit time) flowmeters Reflection (Doppler) flowmeters Open-channel flowmeters // Transit Time flowmeters The most commonly used is the transit time flowmeter which is applied for clean or nearly clean fluids, as well as natural gas pipe systems. ...

Ultrasound also plays a role in Sonic weaponry. Sonic and ultrasonic weapons (USW) are weapons of various types that use sound to injure, incapacitate, or kill an opponent. ...

Audio can be propagated by modulated ultrasound. Ultrasound can be modulated to carry an audio signal (like radio signals are modulated). ...

Nonlinear propagation effects

Because of their high amplitude to wavelength ratio, ultrasonic waves commonly display nonlinear propagation. This article or section is in need of attention from an expert on the subject. ...

See also

Acoustics is the interdisciplinary sciences that always deals with the study of sound, ultrasound and infrasound (all mechanical waves in gases, liquids, and solids). ... Infrasound is sound with a frequency too low to be detected by the human ear. ... // This page is about modulated ultrasound that can make its carried signal audible without needing a receiver set. ... Sonography redirects here. ... When an ultrashort light pulse (duration: ~ 100 fs, energy: <1 nJ) is absorbed at the surface of a thin metal film, the resulting thermal expansion of the surface results in the generation of a strain pulse (composed of longitudinal acoustic phonons) that propagates into the film and the substrate. ... This article is about audible acoustic waves. ... Surface waves in water This article is about waves in the most general scientific sense. ... For other uses, see Light (disambiguation). ...


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  7. ^ FDA Radiological Health - Ultrasound Imaging
  8. ^ Ultrasound Can Affect Fetal Brain Development | LiveScience
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  10. ^ Patient Information - Ultrasound Safety
  11. ^ Ultrasound for fetal assessment in early pregnancy.
  12. ^ http://www.efsumb.org/efsumb/committees/Safety_Committee/Safety_Eng/Clinical%20Safety%20Statement%202006.pdf
  13. ^ Essentials of Medical Ultrasound: A Practical Introduction to the Principles, Techniques and Biomedical Applications, edited by M. H. Rapacholi, Humana Press 1982
  14. ^ Ultrasound - Pelvis.
  15. ^ Acoustic targeted drug delivery in neurological tissue.
  16. ^ A phantom feasibility study of acoustic enhanced drug delivery to neurological tissue.
  17. ^ Acoustics and brain cancer.
  18. ^ Citation list.
  19. ^ Milton B. Larson, Study of the Effects of Ultrasonic Vibrations on Convective Heat Transfer in Liquids, (1960)
  20. ^ Using Infrared To See If You're Lit
  21. ^ Microbial contamination by ultrasonic humidifier
  22. ^ Cancel, Juan (1998). Frequency of Bat Sonar. The Physics Factbook.
  23. ^ Mann DA, et al. (2001) Ultrasound detection by clupeiform fishes. JASA 109 (6), 3048-3054 | doi:10.1121/1.1368406

Further reading

  • Kundu, Tribikram. Ultrasonic nondestructive evaluation : engineering and biological material characterization. Boca Raton, FL: CRC Press, c2004. ISBN 0849314623.

  Results from FactBites:
Ultrasound - Wikipedia, the free encyclopedia (873 words)
Ultrasound is sound with a frequency greater than the upper limit of human hearing, this limit being approximately 20 kilohertz (20,000 hertz).
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Medical ultrasonography - Wikipedia, the free encyclopedia (2626 words)
Ultrasound image quality is limited by the amount of overlying adipose(fat) tissue, as the fatty tissue tends to scatter the sound and greater depth leads to attenuation of the sound beam.
Ultrasound is commonly used during pregnancy to check on the development of the fetus.
Ultrasound performs very poorly when there is a gas between the scan head and the organ of interest, due to the extreme differences in acoustical impedance.
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