Ultrasound is sound with frequencies greater than 20 kHz. This frequency is the approximate upper audible limit of human hearing.
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Ultrasound or ultrasonic may also refer to:
Ultrasound is sound with frequencies greater than 20 kHz. This frequency is the approximate upper audible limit of human hearing.
Ultrasound or ultrasonic may also refer to:
Ultrasound is sound with frequencies greater than 20 kilohertz. This frequency is the approximate upper audible limit of human hearing in healthy young adults. The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz.
Ultrasonic welding is an industrial process whereby high-frequency ultrasonic acoustic vibrations are locally applied to work pieces being held together under pressure to create a solid-state weld. It is commonly used for plastics and metals, and especially for joining dissimilar materials. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. When used to join metals, the temperature stays well below the melting point of the involved materials, preventing any unwanted properties which may arise from high temperature exposure of the metal.
Sonic and ultrasonic weapons (USW) are weapons of various types that use sound to injure or incapacitate an opponent. Some sonic weapons make a focused beam of sound or of ultrasound; others produce an area field of sound. As of 2023 military and police forces make some limited use of sonic weapons.
Plastic welding is welding for semi-finished plastic materials, and is described in ISO 472 as a process of uniting softened surfaces of materials, generally with the aid of heat. Welding of thermoplastics is accomplished in three sequential stages, namely surface preparation, application of heat and pressure, and cooling. Numerous welding methods have been developed for the joining of semi-finished plastic materials. Based on the mechanism of heat generation at the welding interface, welding methods for thermoplastics can be classified as external and internal heating methods, as shown in Fig 1.
An electric toothbrush is a toothbrush that makes rapid automatic bristle motions, either back-and-forth oscillation or rotation-oscillation, in order to clean teeth. Motions at sonic speeds or below are made by a motor. In the case of ultrasonic toothbrushes, ultrasonic motions are produced by a piezoelectric crystal. A modern electric toothbrush is usually powered by a rechargeable battery charged through inductive charging when the brush sits in the charging base between uses.
Ultrasonic cleaning is a process that uses ultrasound to agitate a fluid, with a cleaning effect. Ultrasonic cleaners come in a variety of sizes, from small desktop units with an internal volume of less than 0.5 litres (0.13 US gal), to large industrial units with volumes approaching 1,000 litres.
Ultrasonic testing (UT) is a family of non-destructive testing techniques based on the propagation of ultrasonic waves in the object or material tested. In most common UT applications, very short ultrasonic pulse-waves with center frequencies ranging from 0.1-15 MHz, and occasionally up to 50 MHz, are transmitted into materials to detect internal flaws or to characterize materials. A common example is ultrasonic thickness measurement, which tests the thickness of the test object, for example, to monitor pipework corrosion.
Sound from ultrasound is the name given here to the generation of audible sound from modulated ultrasound without using an active receiver. This happens when the modulated ultrasound passes through a nonlinear medium which acts, intentionally or unintentionally, as a demodulator.
A scanning acoustic microscope (SAM) is a device which uses focused sound to investigate, measure, or image an object. It is commonly used in failure analysis and non-destructive evaluation. It also has applications in biological and medical research. The semiconductor industry has found the SAM useful in detecting voids, cracks, and delaminations within microelectronic packages.
Ultrasonic transducers and ultrasonic sensors are devices that generate or sense ultrasound energy. They can be divided into three broad categories: transmitters, receivers and transceivers. Transmitters convert electrical signals into ultrasound, receivers convert ultrasound into electrical signals, and transceivers can both transmit and receive ultrasound.
Ultrasound energy, simply known as ultrasound, is a type of mechanical energy called sound characterized by vibrating or moving particles within a medium. Ultrasound is distinguished by vibrations with a frequency greater than 20,000 Hz, compared to audible sounds that humans typically hear with frequencies between 20 and 20,000 Hz. Ultrasound energy requires matter or a medium with particles to vibrate to conduct or propagate its energy. The energy generally travels through most mediums in the form of a wave in which particles are deformed or displaced by the energy then reestablished after the energy passes. Types of waves include shear, surface, and longitudinal waves with the latter being one of the most common used in biological applications. The characteristics of the traveling ultrasound energy greatly depend on the medium that it is traveling through. While ultrasound waves propagate through a medium, the amplitude of the wave is continually reduced or weakened with the distance it travels. This is known as attenuation and is due to the scattering or deflecting of energy signals as the wave propagates and the conversion of some of the energy to heat energy within the medium. A medium that changes the mechanical energy from the vibrations of the ultrasound energy into thermal or heat energy is called viscoelastic. The properties of ultrasound waves traveling through the medium of biological tissues has been extensively studied in recent years and implemented into many important medical tools.
Ultrasonic soldering is a flux-less soldering process that uses ultrasonic energy, without the need for chemicals to solder materials, such as glass, ceramics, and composites, hard to solder metals and other sensitive components which cannot be soldered using conventional means.
Acoustic microscopy is microscopy that employs very high or ultra high frequency ultrasound. Acoustic microscopes operate non-destructively and penetrate most solid materials to make visible images of internal features, including defects such as cracks, delaminations and voids.
Thermoacoustic imaging was originally proposed by Theodore Bowen in 1981 as a strategy for studying the absorption properties of human tissue using virtually any kind of electromagnetic radiation. But Alexander Graham Bell first reported the physical principle upon which thermoacoustic imaging is based a century earlier. He observed that audible sound could be created by illuminating an intermittent beam of sunlight onto a rubber sheet. Shortly after Bowen's work was published, other researchers proposed methodology for thermoacoustic imaging using microwaves. In 1994 researchers used an infrared laser to produce the first thermoacoustic images of near-infrared optical absorption in a tissue-mimicking phantom, albeit in two dimensions (2D). In 1995 other researchers formulated a general reconstruction algorithm by which 2D thermoacoustic images could be computed from their "projections," i.e. thermoacoustic computed tomography (TCT). By 1998 researchers at Indiana University Medical Center extended TCT to 3D and employed pulsed microwaves to produce the first fully three-dimensional (3D) thermoacoustic images of biologic tissue [an excised lamb kidney ]. The following year they created the first fully 3D thermoacoustic images of cancer in the human breast, again using pulsed microwaves. Since that time, thermoacoustic imaging has gained widespread popularity in research institutions worldwide. As of 2008, three companies were developing commercial thermoacoustic imaging systems – Seno Medical, Endra, Inc. and OptoSonics, Inc.
The photoacoustic Doppler effect is a type of Doppler effect that occurs when an intensity modulated light wave induces a photoacoustic wave on moving particles with a specific frequency. The observed frequency shift is a good indicator of the velocity of the illuminated moving particles. A potential biomedical application is measuring blood flow.
In the field of industrial ultrasonic testing, ultrasonic thickness measurement (UTM) is a method of performing non-destructive measurement (gauging) of the local thickness of a solid element based on the time taken by the ultrasound wave to return to the surface. This type of measurement is typically performed with an ultrasonic thickness gauge.
Ultrasound-modulated optical tomography (UOT), also known as Acousto-Optic Tomography (AOT), is a hybrid imaging modality that combines light and sound; it is a form of tomography involving ultrasound. It is used in imaging of biological soft tissues and has potential applications for early cancer detection. As a hybrid modality which uses both light and sound, UOT provides some of the best features of both: the use of light provides strong contrast and sensitivity ; these two features are derived from the optical component of UOT. The use of ultrasound allows for high resolution, as well as a high imaging depth. However, the difficulty of tackling the two fundamental problems with UOT have caused UOT to evolve relatively slowly; most work in the field is limited to theoretical simulations or phantom / sample studies.
Home ultrasound is the provision of therapeutic ultrasound via the use of a portable or home ultrasound machine. This method of medical ultrasound therapy can be used for various types of pain relief and physical therapy.
Ultrasonic antifouling is a technology that uses high frequency sound (ultrasound) to prevent or reduce biofouling on underwater structures, surfaces, and medium. Ultrasound is just high frequency sound. Ultrasound has the same physical properties as human-audible sound. The method has two primary forms: sub-cavitation intensity and cavitation intensity. Sub-cavitation methods create high frequency vibrations, whilst cavitation methods cause more destructive microscopic pressure changes. Both methods inhibit or prevent biofouling by algae and other single-celled organisms.
Ultrasound computer tomography (USCT), sometimes also Ultrasound computed tomography, Ultrasound computerized tomography or just Ultrasound tomography, is a form of medical ultrasound tomography utilizing ultrasound waves as physical phenomenon for imaging. It is mostly in use for soft tissue medical imaging, especially breast imaging.