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Middle Ear Barotrauma
Middle ear barotrauma (MEBT), also known to underwater divers as ear squeeze and reverse ear squeeze, is an injury caused by a difference in pressure between the external ear canal and the middle ear. It is common in underwater divers and usually occurs when the diver does not equalise sufficiently during descent or, less commonly, on ascent. Failure to equalise may be due to inexperience or eustachian tube dysfunction, which can have many possible causes. Unequalised ambient pressure increase during descent causes a pressure imbalance between the middle ear air space and the external auiditory canal over the eardrum, referred to by divers as ear squeeze, causing inward stretching, serous effusion and haemorrhage, and eventual rupture. During ascent internal over-pressure is normally passively released through the eustachian tube, but if this does not happen the volume expansion of middle ear gas will cause outward bulging, stretching and eventual rupture of the eardrum known t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Ear Barotrauma
Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tension or shear, either directly by an expansion of the gas in the closed space or by pressure difference hydrostatically transmitted through the tissue. Tissue rupture may be complicated by the introduction of gas into the local tissue or circulation through the initial trauma site, which can cause blockage of circulation at distant sites or interfere with the normal function of an organ by its presence. Barotrauma generally manifests as sinus or middle ear effects, lung overpressure injuries and injuries resulting from external squeezes. Decompression sickness is indirectly caused by ambient pressure reduction, and tissue damage is caused directly and indirectly by gas bubbles. However, these bubbles form out of supersaturated solution fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Submersible
A submersible is a small watercraft designed to operate underwater. The term "submersible" is often used to differentiate from other underwater vessels known as submarines, in that a submarine is a fully self-sufficient craft, capable of independent cruising with its own power supply and air renewal system, whereas a submersible is usually supported by a nearby ship, surface vessel, very large floating structure, platform, shore team or sometimes a larger submarine. In common usage by the general public, however, the word "submarine" may be used to describe a craft that is by the technical definition actually a submersible. There are many types of submersibles, including both crewed and uncrewed craft, otherwise known as remotely operated vehicles (ROVs) or unmanned underwater vehicles (UUVs). Submersibles have many uses worldwide, such as oceanography, underwater archaeology, ocean exploration, adventure, equipment maintenance and recovery, and underwater videography. Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestibular Neuronitis
Labyrinthitis is inflammation of the labyrinth – a maze of fluid-filled channels in the inner ear. Vestibular neuritis is inflammation of the vestibular nerve – the nerve in the inner ear that sends messages related to motion and position to the brain. Both conditions involve inflammation of the inner ear. Labyrinths that house the vestibular system sense changes in the head's position or the head's motion. Inflammation of these inner ear parts results in a sensation of the world spinning and also possible hearing loss or ringing in the ears. It can occur as a single attack, a series of attacks, or a persistent condition that diminishes over three to six weeks. It may be associated with nausea, vomiting, and eye nystagmus. The cause is often not clear. It may be due to a virus, but it can also arise from bacterial infection, head injury, extreme stress, an allergy, or as a reaction to medication. 30% of affected people had a common cold prior to developing the disease. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benign Paroxysmal Positional Vertigo
Benign paroxysmal positional vertigo (BPPV) is a disorder arising from a problem in the inner ear. Symptoms are repeated, brief periods of vertigo with movement, characterized by a spinning sensation upon changes in the position of the head. * This can occur with turning in bed or changing position. Each episode of vertigo typically lasts less than one minute. Nausea is commonly associated. BPPV is one of the most common causes of vertigo. BPPV is a type of balance disorder along with labyrinthitis and Ménière's disease. It can result from a head injury or simply occur among those who are older. Often, a specific cause is not identified. When found, the underlying mechanism typically involves a small calcified otolith moving around loose in the inner ear. Diagnosis is typically made when the Dix–Hallpike test results in nystagmus (a specific movement pattern of the eyes) and other possible causes have been ruled out. In typical cases, medical imaging is not needed. BPPV is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Ear Decompression Sickness
Inner ear decompression sickness, (IEDCS) or audiovestibular decompression sickness is a medical condition of the inner ear caused by the formation of gas bubbles in the tissues or blood vessels of the inner ear. Generally referred to as a form of decompression sickness, it can also occur at constant pressure due to inert gas counterdiffusion effects. Usually only one side is affected, and the most common symptoms are vertigo with nystagmus, loss of balance, and nausea. The symptoms are similar to those caused by some other diving injuries and differential diagnosis can be complicated and uncertain if several possible causes for the symptoms coexist. First aid is breathing the highest practicable concentration of normobaric oxygen. Definitive treatment is recompression with hyperbaric oxygen therapy. Anti-vertigo and anti-nausea drugs are usually effective at suppressing symptoms, but do not reduce the tissue damage. Hyperbaric oxygen may be effective for reducing oedema and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otitis Externa
Otitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is typically not present except in severe cases. Otitis externa may be acute (lasting less than six weeks) or chronic (lasting more than three months). Acute cases are typically due to bacterial infection, and chronic cases are often due to allergies and autoimmune disorders. the most common cause of Otitis externa is bacterial. Risk factors for acute cases include swimming, minor trauma from cleaning, using hearing aids and ear plugs, and other skin problems, such as psoriasis and dermatitis. People with diabetes are at risk of a severe form of ''malignant otitis externa''. Diagnosis is based on the signs and symptoms. Culturing the ear canal may be useful in chronic or severe cases. Acetic acid ear drops may be used as a preventive measur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otitis Media
Otitis media is a group of inflammatory diseases of the middle ear. One of the two main types is acute otitis media (AOM), an infection of rapid onset that usually presents with ear pain. In young children this may result in pulling at the ear, increased crying, and poor sleep. Decreased eating and a fever may also be present. The other main type is otitis media with effusion (OME), typically not associated with symptoms, although occasionally a feeling of fullness is described; it is defined as the presence of non-infectious fluid in the middle ear which may persist for weeks or months often after an episode of acute otitis media. Chronic suppurative otitis media (CSOM) is middle ear inflammation that results in a perforated tympanic membrane with discharge from the ear for more than six weeks. It may be a complication of acute otitis media. Pain is rarely present. All three types of otitis media may be associated with hearing loss. If children with hearing loss due to OME do no ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Differential Diagnosis
In healthcare, a differential diagnosis (abbreviated DDx) is a method of analysis of a patient's history and physical examination to arrive at the correct diagnosis. It involves distinguishing a particular disease or condition from others that present with similar clinical features. Differential diagnostic procedures are used by clinicians to diagnose the specific disease in a patient, or, at least, to consider any imminently life-threatening conditions. Often, each individual option of a possible disease is called a differential diagnosis (e.g., acute bronchitis could be a differential diagnosis in the evaluation of a cough, even if the final diagnosis is common cold). More generally, a differential diagnostic procedure is a systematic diagnostic method used to identify the presence of a disease entity where multiple alternatives are possible. This method may employ algorithms, akin to the process of elimination, or at least a process of obtaining information that shrinks the "p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastrointestinal Tract
The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive system, in humans and other animals, including the esophagus, stomach, and intestines. Food taken in through the mouth is digestion, digested to extract nutrients and absorb energy, and the waste expelled at the anus as feces. ''Gastrointestinal'' is an adjective meaning of or pertaining to the stomach and intestines. Nephrozoa, Most animals have a "through-gut" or complete digestive tract. Exceptions are more primitive ones: sponges have small pores (ostium (sponges), ostia) throughout their body for digestion and a larger dorsal pore (osculum) for excretion, comb jellies have both a ventral mouth and dorsal anal pores, while cnidarians and acoels have a single pore for both digestion and excretion. The human gastrointestinal tract consists o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left and on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Longitudinal Wave
Longitudinal waves are waves in which the vibration of the medium is parallel ("along") to the direction the wave travels and displacement of the medium is in the same (or opposite) direction of the wave propagation. Mechanical longitudinal waves are also called ''compressional'' or compression waves, because they produce compression and rarefaction when traveling through a medium, and pressure waves, because they produce increases and decreases in pressure. A wave along the length of a stretched Slinky toy, where the distance between coils increases and decreases, is a good visualization. Real-world examples include sound waves (vibrations in pressure, a particle of displacement, and particle velocity propagated in an elastic medium) and seismic P-waves (created by earthquakes and explosions). The other main type of wave is the transverse wave, in which the displacements of the medium are at right angles to the direction of propagation. Transverse waves, for instance, describe ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uncontrolled Decompression
Uncontrolled decompression is an unplanned drop in the pressure of a sealed system, such as an aircraft cabin or hyperbaric chamber, and typically results from human reliability, human error, fatigue (material), material fatigue, engineering failure, or impact (mechanics), impact, causing a pressure vessel to vent into its lower-pressure surroundings or fail to pressurize at all. Such decompression may be classed as ''explosive, rapid'', or ''slow'': * Explosive decompression (ED) is violent and too fast for air to escape safely from the lungs and other air-filled cavities in the body such as the Paranasal sinuses, sinuses and eustachian tubes, typically resulting in severe to fatal barotrauma. * Rapid decompression may be slow enough to allow cavities to vent but may still cause serious barotrauma or discomfort. * Slow or gradual decompression occurs so slowly that it may not be sensed before Hypoxia (medical), hypoxia sets in. Description The term ''uncontrolled decompression'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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