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Slit Lamp
In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segment and posterior segment of the human eye, which includes the eyelid, sclera, conjunctiva, iris (anatomy), iris, natural crystalline lens, and cornea. The binocular slit-lamp examination provides a stereoscopic magnified view of the eye structures in detail, enabling anatomical diagnoses to be made for a variety of eye conditions. A second, hand-held lens is used to examine the retina. History Two conflicting trends emerged in the development of the slit lamp. One trend originated from clinical research and aimed to apply the increasingly complex and advanced technology of the time. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermann Von Helmholtz
Hermann Ludwig Ferdinand von Helmholtz (; ; 31 August 1821 – 8 September 1894; "von" since 1883) was a German physicist and physician who made significant contributions in several scientific fields, particularly hydrodynamic stability. The Helmholtz Association, the largest German association of research institutions, was named in his honour. In the fields of physiology and psychology, Helmholtz is known for his mathematics concerning the eye, theories of vision, ideas on the visual perception of space, colour vision research, the sensation of tone, perceptions of sound, and empiricism in the physiology of perception. In physics, he is known for his theories on the conservation of energy and on the electrical double layer, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics. Although credit is shared with Julius von Mayer, James Joule, and Daniel Bernoulli—among others—for the energy conservation principles that e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscope
A microscope () is a laboratory equipment, laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisible to the eye unless aided by a microscope. There are many types of microscopes, and they may be grouped in different ways. One way is to describe the method an instrument uses to interact with a sample and produce images, either by sending a beam of light or electrons through a sample in its optical path, by detecting fluorescence, photon emissions from a sample, or by scanning across and a short distance from the surface of a sample using a probe. The most common microscope (and the first to be invented) is the optical microscope, which uses lenses to refract visible light that passed through a microtome, thinly sectioned sample to produce an observable image. Other major types of microscopes are the fluorescence micro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the world's countries participated, with many nations mobilising all resources in pursuit of total war. Tanks in World War II, Tanks and Air warfare of World War II, aircraft played major roles, enabling the strategic bombing of cities and delivery of the Atomic bombings of Hiroshima and Nagasaki, first and only nuclear weapons ever used in war. World War II is the List of wars by death toll, deadliest conflict in history, causing World War II casualties, the death of 70 to 85 million people, more than half of whom were civilians. Millions died in genocides, including the Holocaust, and by massacres, starvation, and disease. After the Allied victory, Allied-occupied Germany, Germany, Allied-occupied Austria, Austria, Occupation of Japan, Japan, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joystick
A joystick, sometimes called a flight stick, is an input device consisting of a stick that pivots on a base and reports its angle or direction to the device it is controlling. Also known as the control column, it is the principal control device in the cockpit of many civilian and military aircraft, either as a centre stick or side-stick. It has various switches to control functions of the aircraft controlled by the Pilot and First Officer of the flight. Joysticks are often used to control video games, and usually have push-buttons whose state can be read by the computer. A popular variation of the joystick used on modern video game consoles is the analog stick. Joysticks are also used for controlling machines such as cranes, trucks, underwater unmanned vehicles, wheelchairs, surveillance cameras, and Zero-turn mower, zero turning radius lawn mowers. Miniature finger-operated joysticks have been adopted as input devices for smaller electronic equipment such as mobile phones. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hans Goldmann
Hans Goldmann (20 November 1899 in Komotau, Kingdom of Bohemia, Austro-Hungarian Empire – 19 November 1991 in Bern) was an Austrian-Swiss ophthalmologist and inventor. Biography Goldmann completed his Gymnasium education in Komotau (now known as Chomutov). At the urging of his father, from 1919 he studied medicine at the Charles University in Prague although he originally wanted to study astronomy. In 1923 he completed his studies and received his doctorate in medicine. From 1919 to 1924 he was an assistant to the physiologist Armin von Tschermak-Seysenegg at the Institute of Physiology of Charles University and was assistant to the ophthalmologist Anton Elschnig at the eye clinic of Charles University. In 1924 Goldmann went to Bern as assistant to August Siegrist at the eye clinic of the University of Bern. In 1927 he became there a senior physician (''Oberarzt''). In 1930 he received his ophthalmic Habilitation and became a Privatdozent. In 1935 he married Erna Renfer. In 19 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stereo Camera
A stereo camera is a type of camera with two or more lenses with a separate image sensor or film frame for each lens. This allows the camera to simulate human binocular vision, and therefore gives it the ability to capture three-dimensional images, a process known as stereo photography. Stereo cameras may be used for making stereoviews and 3D pictures for movies, or for range imaging. The distance between the lenses in a typical stereo camera (the intra-axial distance) is about the distance between one's eyes (known as the intra-ocular distance) and is about 6.35 cm, though a longer base line (greater inter-camera distance) produces more extreme 3-dimensionality. In the 1950s, stereo cameras gained some popularity with the Stereo Realist and similar cameras that employed 135 film to make stereo slides. 3D pictures following the theory behind stereo cameras can also be made more inexpensively by taking two pictures with the same camera, but moving the camera a few ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Arc
An arc lamp or arc light is a lamp that produces light by an electric arc (also called a voltaic arc). The carbon arc light, which consists of an arc between carbon electrodes in air, invented by Humphry Davy in the first decade of the 1800s, was the first practical electric light. It was widely used starting in the 1870s for street and large building lighting until it was superseded by the incandescent light in the early 20th century. It continued in use in more specialized applications where a high intensity point light source was needed, such as searchlights and movie projectors until after World War II. The carbon arc lamp is now obsolete for most of these purposes, but it is still used as a source of high intensity ultraviolet light. The term is now used for gas discharge lamps, which produce light by an arc between metal electrodes through a gas in a glass bulb. The common fluorescent lamp is a low-pressure mercury arc lamp. The xenon arc lamp, which produces a high ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incandescent Light Bulb
An incandescent light bulb, also known as an incandescent lamp or incandescent light globe, is an electric light that produces illumination by Joule heating a #Filament, filament until it incandescence, glows. The filament is enclosed in a glass bulb that is either vacuum, evacuated or filled with inert gas to protect the filament from oxidation. Electric current is supplied to the filament by terminals or wires embedded in the glass. A bulb socket provides mechanical support and electrical connections. Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external Regulator (automatic control), regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent bulb became widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Koehler Illumination
Koehler is a transliteration of the German occupational surname Köhler, literally meaning "charcoal burner". Notable people with the surname include: * Ana Luiza Koehler (born 1977), Brazilian comics artist and architect. * Arthur Koehler (1885–1967), American investigator notable for his role in the Lindbergh kidnapping investigation * Bernhard Koehler (1849–1927), German industrialist and art collector *Carl-Erik Koehler (1895–1958), German general during World War II * Carla Koehler, American biochemist * Don Koehler (1925–1981), American recognized as tallest man in the world from 1969 to 1981 * Ernest Koehler (1903–1960), American Olympic racewalker * Florence Koehler (1861–1944), American craftswoman, designer and jeweler *Frederick Koehler (born 1975), American actor * Garry Koehler (1955–2019), Australian songwriter * Greg Koehler (born 1975), Canadian ice hockey player for the Bloomington Prairie Thunder in the International Hockey League *Herman Koehl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophthalmoscope
Ophthalmoscopy, also called funduscopy, is a test that allows a health professional to see inside the fundus of the eye and other structures using an ophthalmoscope (or funduscope). It is done as part of an eye examination and may be done as part of a routine physical examination. It is crucial in determining the health of the retina, optic disc, and vitreous humor. The pupil is a hole through which the eye's interior can be viewed. For better viewing, the pupil can be opened wider (dilated; mydriasis) before ophthalmoscopy using medicated eye drops ( dilated fundus examination). However, undilated examination is more convenient (albeit not as comprehensive), and is the most common type in primary care. An alternative or complement to ophthalmoscopy is to perform a fundus photography, where the image can be analysed later by a professional. Types There are two major types of ophthalmoscopy: * direct ophthalmoscopy, which produces an upright (unreversed) image of approxim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nernst Glower
The Nernst lamp was an early form of incandescent lamp. Construction Nernst lamps did not use a glowing tungsten filament. Instead, they used a ceramic rod that was heated to incandescence. Because the rod (unlike tungsten wire) would not further oxidize when exposed to air, there was no need to enclose it within a vacuum or noble gas environment; the burners in Nernst lamps could operate exposed to the air and were only enclosed in glass to isolate the hot incandescent emitter from its environment. A ceramic of zirconium oxide – yttrium oxide was used as the glowing rod. Efficiency Developed by the German physicist and chemist Walther Nernst in 1897 at the University of Göttingen, these lamps were about twice as efficient as carbon-filament lamps and emitted a more "natural" light (more similar in spectrum to daylight). The lamps were quite successfully marketed for a time, although they eventually lost out to the more efficient tungsten-filament incandescent light b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
