Products or parts of products used to detect, manipulate, or analyze light, such as LENSES, refractors, mirrors, filters, prisms, and OPTICAL FIBERS.
Measurement of the index of refraction (the ratio of the velocity of light or other radiation in the first of two media to its velocity in the second as it passes from one into the other).
The property of nonisotropic media, such as crystals, whereby a single incident beam of light traverses the medium as two beams, each plane-polarized, the planes being at right angles to each other. (Cline et al., Dictionary of Visual Science, 4th ed)
Equipment used to prevent contamination of and by patients, especially those with bacterial infections. This includes plastic surgical isolators and isolators used to protect immunocompromised patients.
Behavior of LIGHT and its interactions with itself and materials.
A physical property showing different values in relation to the direction in or along which the measurement is made. The physical property may be with regard to thermal or electric conductivity or light refraction. In crystallography, it describes crystals whose index of refraction varies with the direction of the incident light. It is also called acolotropy and colotropy. The opposite of anisotropy is isotropy wherein the same values characterize the object when measured along axes in all directions.
Exclusive legal rights or privileges applied to inventions, plants, etc.
Materials that have a limited and usually variable electrical conductivity. They are particularly useful for the production of solid-state electronic devices.
Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).
The theory that the radiation and absorption of energy take place in definite quantities called quanta (E) which vary in size and are defined by the equation E=hv in which h is Planck's constant and v is the frequency of the radiation.
A mild astringent and topical protectant with some antiseptic action. It is also used in bandages, pastes, ointments, dental cements, and as a sunblock.
An X-linked inherited metabolic disease caused by a deficiency of lysosomal ALPHA-GALACTOSIDASE A. It is characterized by intralysosomal accumulation of globotriaosylceramide and other GLYCOSPHINGOLIPIDS in blood vessels throughout the body leading to multi-system complications including renal, cardiac, cerebrovascular, and skin disorders.
Nanometer sized fragments of semiconductor crystalline material which emit PHOTONS. The wavelength is based on the quantum confinement size of the dot. They can be embedded in MICROBEADS for high throughput ANALYTICAL CHEMISTRY TECHNIQUES.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
An island in the Gulf of St. Lawrence constituting a province of Canada in the eastern part of the country. It is very irregular in shape with many deep inlets. Its capital is Charlottetown. Discovered by the French in 1534 and originally named Ile Saint-Jean, it was renamed in 1799 in honor of Prince Edward, fourth son of George III and future father of Queen Victoria. (From Webster's New Geographical Dictionary, 1988, p981 & Room, Brewer's Dictionary of Names, 1992, p433)
Surgical insertion of synthetic material to repair injured or diseased heart valves.
A device that substitutes for a heart valve. It may be composed of biological material (BIOPROSTHESIS) and/or synthetic material.
A pathological constriction that can occur above (supravalvular stenosis), below (subvalvular stenosis), or at the AORTIC VALVE. It is characterized by restricted outflow from the LEFT VENTRICLE into the AORTA.
Measurement of the various properties of light.
Strong alkaline chemicals that destroy soft body tissues resulting in a deep, penetrating type of burn, in contrast to corrosives, that result in a more superficial type of damage via chemical means or inflammation. Caustics are usually hydroxides of light metals. SODIUM HYDROXIDE and potassium hydroxide are the most widely used caustic agents in industry. Medically, they have been used externally to remove diseased or dead tissues and destroy warts and small tumors. The accidental ingestion of products (household and industrial) containing caustic ingredients results in thousands of injuries per year.
The recording of images in three-dimensional form on a photographic film by exposing it to a laser beam reflected from the object under study.
Regulations to assure protection of property and equipment.
Protective measures against unauthorized access to or interference with computer operating systems, telecommunications, or data structures, especially the modification, deletion, destruction, or release of data in computers. It includes methods of forestalling interference by computer viruses or so-called computer hackers aiming to compromise stored data.
The misinterpretation of a real external, sensory experience.
Methods utilizing the principles of MICROFLUIDICS for sample handling, reagent mixing, and separation and detection of specific components in fluids.
The study of fluid channels and chambers of tiny dimensions of tens to hundreds of micrometers and volumes of nanoliters or picoliters. This is of interest in biological MICROCIRCULATION and used in MICROCHEMISTRY and INVESTIGATIVE TECHNIQUES.
Solutions prepared for exchange across a semipermeable membrane of solutes below a molecular size determined by the cutoff threshold of the membrane material.
Silicone polymers which consist of silicon atoms substituted with methyl groups and linked by oxygen atoms. They comprise a series of biocompatible materials used as liquids, gels or solids; as film for artificial membranes, gels for implants, and liquids for drug vehicles; and as antifoaming agents.
A specialized field of physics and engineering involved in studying the behavior and properties of light and the technology of analyzing, generating, transmitting, and manipulating ELECTROMAGNETIC RADIATION in the visible, infrared, and ultraviolet range.
Sterile solutions used to clean and disinfect contact lenses.
Process that is gone through in order for a device to receive approval by a government regulatory agency. This includes any required preclinical or clinical testing, review, submission, and evaluation of the applications and test results, and post-marketing surveillance. It is not restricted to FDA.
Expendable and nonexpendable equipment, supplies, apparatus, and instruments that are used in diagnostic, surgical, therapeutic, scientific, and experimental procedures.
Freedom of equipment from actual or potential hazards.
Laws and regulations pertaining to devices used in medicine, proposed for enactment, or enacted by a legislative body.
Inorganic compounds that contain iodine as an integral part of the molecule.
Stable elementary particles having the smallest known negative charge, present in all elements; also called negatrons. Positively charged electrons are called positrons. The numbers, energies and arrangement of electrons around atomic nuclei determine the chemical identities of elements. Beams of electrons are called CATHODE RAYS.
The branch of science that deals with the geometric description of crystals and their internal arrangement. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
Information systems, usually computer-assisted, designed to store, manipulate, and retrieve information for planning, organizing, directing, and controlling administrative activities associated with the provision and utilization of radiology services and facilities.
Calamities producing great damage, loss of life, and distress. They include results of natural phenomena and man-made phenomena. Normal conditions of existence are disrupted and the level of impact exceeds the capacity of the hazard-affected community.
That portion of the electromagnetic spectrum usually sensed as heat. Infrared wavelengths are longer than those of visible light, extending into the microwave frequencies. They are used therapeutically as heat, and also to warm food in restaurants.
Inorganic compounds that contain cadmium as an integral part of the molecule.
The professional practice of primary eye and vision care that includes the measurement of visual refractive power and the correction of visual defects with lenses or glasses.
A surgical specialty concerned with the structure and function of the eye and the medical and surgical treatment of its defects and diseases.
A vacuum tube equipped with an electron emitting CATHODE and a fluorescent screen which emits visible light when excited by the cathode ray. Cathode ray tubes are used as imaging devises for TELEVISIONS; COMPUTER TERMINALS; TEXT TELECOMMUNICATION DEVICES; oscilloscopes; and other DATA DISPLAY devices.
The prevention of access by infecting organisms to the locus of potential infection.
Hafnium. A metal element of atomic number 72 and atomic weight 178.49, symbol Hf. (From Dorland, 28th ed)
The study, control, and application of the conduction of ELECTRICITY through gases or vacuum, or through semiconducting or conducting materials. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
The continuous measurement of physiological processes, blood pressure, heart rate, renal output, reflexes, respiration, etc., in a patient or experimental animal; includes pharmacologic monitoring, the measurement of administered drugs or their metabolites in the blood, tissues, or urine.
Any of the 23 plates of fibrocartilage found between the bodies of adjacent VERTEBRAE.
An INTERVERTEBRAL DISC in which the nucleus pulposus has protruded through surrounding fibrocartilage. This occurs most frequently in the lower lumbar region.
Degenerative changes in the INTERVERTEBRAL DISC due to aging or structural damage, especially to the vertebral end-plates.
An extraction method that separates analytes using a solid phase and a liquid phase. It is used for preparative sample cleanup before analysis by CHROMATOGRAPHY and other analytical methods.
The total process by which organisms produce offspring. (Stedman, 25th ed)