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Von Frey Hair
An esthesiometer (British spelling aesthesiometer) is a device for measuring the tactile sensitivity of the skin (or mouth, or eye, etc.). The measure of the degree of tactile sensitivity is called aesthesiometry. The device was invented by Edward Henry Sieveking. There are different types of aesthesiometers depending on their particular function. Two-point discrimination The simplest is a manual tool with adjustable points similar to a caliper. It can determine how short a distance between two impressions on the skin can be distinguished. To differentiate between two points and one point of equal area (the sum of the areas of the two points equals the area of the third point), Dr. Sidney Weinstein created the three-point esthesiometer. A scale on the instrument gives readings in millimeter gradients. Monofilaments Another type of manual aesthesiometer is used to test lower thresholds of touch or pain. The tool uses nylon monofilaments with varying calibrated diameters. The for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esthesiometer From C
An esthesiometer (British spelling aesthesiometer) is a device for measuring the Somatosensory system, tactile sensitivity of the skin (or mouth, or eye, etc.). The measure of the degree of tactile sensitivity is called aesthesiometry. The device was invented by Edward Henry Sieveking. There are different types of aesthesiometers depending on their particular function. Two-point discrimination The simplest is a manual tool with adjustable points similar to a caliper. It can determine how short a distance between two impressions on the skin can be distinguished. To differentiate between two points and one point of equal area (the sum of the areas of the two points equals the area of the third point), Dr. Sidney Weinstein created the three-point esthesiometer. A scale on the instrument gives readings in millimeter gradients. Monofilaments Another type of manual aesthesiometer is used to test lower thresholds of touch or pain. The tool uses nylon Monofilament fishing line, monofila ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatosensory System
In physiology, the somatosensory system is the network of neural structures in the brain and body that produce the perception of touch (haptic perception), as well as temperature (thermoception), body position (proprioception), and pain. It is a subset of the sensory nervous system, which also represents visual, auditory, olfactory, and gustatory stimuli. Somatosensation begins when mechano- and thermosensitive structures in the skin or internal organs sense physical stimuli such as pressure on the skin (see mechanotransduction, nociception). Activation of these structures, or receptors, leads to activation of peripheral sensory neurons that convey signals to the spinal cord as patterns of action potentials. Sensory information is then processed locally in the spinal cord to drive reflexes, and is also conveyed to the brain for conscious perception of touch and proprioception. Note, somatosensory information from the face and head enters the brain through periphera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edward Henry Sieveking
Sir Edward Henry Sieveking (24 August 1816 – 24 February 1904) was an English physician. Life Sieveking was born in Bishopsgate, London. He studied medicine at the University of Berlin under eminent physiologist Johannes Peter Muller, and also at University College London and the University of Edinburgh, where he received his doctorate in 1841. In 1847, he settled in London, England. In 1851, he was named a physician and lecturer at St Mary's Hospital in London, where he remained for most of his medical career. He was also a physician at London Lock Hospital and the National Hospital for the Paralyzed and Epileptic. Sieveking had many and varied interests in medicine. He was closely involved in the training of nurses and treatment of the poor, and had a keen interest concerning treatment of epilepsy and other neurological disorders. In 1858, he devised an aesthesiometer, a device for measuring tactile sensitivity of the skin. He wrote several books, and was responsible for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aesthesiometer
An esthesiometer (British spelling aesthesiometer) is a device for measuring the tactile sensitivity of the skin (or mouth, or eye, etc.). The measure of the degree of tactile sensitivity is called aesthesiometry. The device was invented by Edward Henry Sieveking. There are different types of aesthesiometers depending on their particular function. Two-point discrimination The simplest is a manual tool with adjustable points similar to a caliper. It can determine how short a distance between two impressions on the skin can be distinguished. To differentiate between two points and one point of equal area (the sum of the areas of the two points equals the area of the third point), Dr. Sidney Weinstein created the three-point esthesiometer. A scale on the instrument gives readings in millimeter gradients. Monofilaments Another type of manual aesthesiometer is used to test lower thresholds of touch or pain. The tool uses nylon monofilaments with varying calibrated diameters. The forc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caliper
A caliper (British spelling also calliper, or in plurale tantum sense a pair of calipers) is a device used to measure the dimensions of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display. Some calipers can be as simple as a compass with inward or outward-facing points, but no scale. The tips of the caliper are adjusted to fit across the points to be measured and the dimension read by measuring between the tips with another measuring tool, such as a ruler. It is used in many fields such as mechanical engineering, metalworking, forestry, woodworking, science and medicine. Plural vs. singular A single tool might be referred to as a "caliper" or as "calipers", like a pair of scissors or glasses (a "plural only" or ''plurale tantum'' form). In colloquial usage, the phrase "pair of verniers" or just " vernier" might refer to a vernier caliper. Colloquially these phrases can also refer to dial calipers, although they in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Millimeter
330px, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is between 1 meter to 1 millimeter. The millimetre (American and British English spelling differences#-re, -er, international spelling; International System of Units, SI unit symbol mm) or millimeter (American and British English spelling differences#-re, -er, American spelling) is a Units of measurement, unit of length in the International System of Units (SI), equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to micrometres or nanometres. Since an inch is officially defined as exactly 25.4 millimetres, a millimetre is equal to exactly (≈ 0.03937) of an inch. Definition Since 1983, the metre has been defined as "the length of the path travelled by light in vacuum during a time interval of of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nylon
Nylon is a generic designation for a family of synthetic polymers composed of polyamides ( repeating units linked by amide links).The polyamides may be aliphatic or semi-aromatic. Nylon is a silk-like thermoplastic, generally made from petroleum, that can be melt-processed into fibers, films, or shapes. Nylon polymers can be mixed with a wide variety of additives to achieve many property variations. Nylon polymers have found significant commercial applications in fabric and fibers (apparel, flooring and rubber reinforcement), in shapes (molded parts for cars, electrical equipment, etc.), and in films (mostly for food packaging). History DuPont and the invention of nylon Researchers at DuPont began developing cellulose based fibers, culminating in the synthetic fiber rayon. DuPont's experience with rayon was an important precursor to its development and marketing of nylon. DuPont's invention of nylon spanned an eleven-year period, ranging from the initial research pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monofilament Fishing Line
Monofilament fishing line (shortened to just mono) is fishing line made from a single fiber of plastic material, as opposed to multifilament or braided fishing lines constructed from multiple strands of fibers. Most fishing lines are now nylon monofilament because they are cheap to produce and can be produced in a range of diameters which have different tensile strengths (called "tests" after the process of tensile testing, or possibly as a portmanteau of "tensile" and "strength"). Monofilament line is also manufactured in different colors, such as clear, white, green, blue, red, and fluorescent. Monofilament is made by melting and mixing polymers and then extruding the mixture through tiny holes, forming strands of line, which is then spun into spools of various thicknesses. The extrusion process controls not only the thickness of the line but its test as well. History DuPont made public in 1938 that their company had invented nylon. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximilian Von Frey
Maximilian (Max) Ruppert Franz von Frey (16 November 1852 – 25 January 1932) was an Austrian-German physiologist who was born in Salzburg. He received his doctorate from the University of Leipzig in 1877, and subsequently worked at Carl Ludwig's Physiological Institute in Leipzig. Later he was a professor of physiology at the Universities of Würzburg and Zurich. Frey's primary work in Leipzig dealt with the circulatory system, and he is credited with developing an early prototype of a heart-lung machine. He is remembered for his work involving cutaneous sensory mechanoreceptors. During the 1890s, Frey proposed that pain is an independent tactile quality, alongside touch, heat and cold, and that it is associated with stimulation of high-threshold free nerve endings. He described the skin as a mosaic of discrete spots, each sensitive to one or another of these stimuli. He created a unique type of esthesiometer, now referred to as a von Frey hair An esthesiometer (British spelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nociceptive
Nociception (also nocioception, from Latin ''nocere'' 'to harm or hurt') is the Somatosensory system, sensory nervous system's process of encoding Noxious stimulus, noxious stimuli. It deals with a series of events and processes required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal in order to trigger an appropriate defense response. In nociception, intense chemical (e.g., capsaicin present in Chili pepper or Cayenne pepper), mechanical (e.g., cutting, crushing), or thermal (heat and cold) stimulation of sensory neurons called nociceptors produces a signal that travels along a chain of nerve fibers via the spinal cord to the brain. Nociception triggers a variety of physiological and behavioral responses to protect the organism against an aggression and usually results in a subjective experience, or perception, of pain in Sentience, sentient beings. Detection of noxious stimuli Potentially damaging mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bruceton Analysis
A Bruceton analysis is one way of analyzing the sensitivity of explosives as described originally by Dixon and Mood in 1948. Also known as the " Up and Down Test" or "the staircase method", a Bruceton analysis relies upon two parameters: first stimulus and step size. A stimulus is provided to the sample, and the results noted. If a positive result is noted, then the stimulus is decremented by the step size. If a negative result occurs, the stimulus is increased. The test continues with each sample tested at a stimulus 1 step up or down from the previous stimulus if the previous result was negative or positive. The results are tabulated and analyzed via Bruceton analysis, a simple computation of sums that can be performed by pencil and paper, to provide estimates of the mean and standard deviation. Confidence estimates are also produced. Other analysis methods are the Neyer d-optimal test and Dror and Steinberg 008sequential procedure. Bruceton analysis has an advantage over the mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornea
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is approximately 43 dioptres. The cornea can be reshaped by surgical procedures such as LASIK. While the cornea contributes most of the eye's focusing power, its focus is fixed. Accommodation (the refocusing of light to better view near objects) is accomplished by changing the geometry of the lens. Medical terms related to the cornea often start with the prefix "'' kerat-''" from the Greek word κέρας, ''horn''. Structure The cornea has unmyelinated nerve endings sensitive to touch, temperature and chemicals; a touch of the cornea causes an involuntary reflex to close the eyelid. Because transparency is of prime importance, the healthy cornea does not have or need blood vessels with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
