| Aural barotraumas,(Aural barotraumas, AB) refers to the aviation flight, the pressure regulating function of the eustachian tube can not adapt to rapid changes in middle ear outside the middle ear cavity pressure, lead to middle ear middle ear cavity pressure and ambient pressure imbalance resulting from the pressure damage, in the aviation environment according to aviation otitis media(aero- otitis), high incidence,while fighter pilot hospital otolaryngology disease and ariations grounded the first bit of [3].The disease incidence in professional pilots, divers, also can be found in ordinary passengers, not only affects normal flight diving training, serious when can cause complicated inner ear and life safety crisis in diseases of the nervous system.This study through the establishment of a dynamic model of the AB,observing animal behavior change, the ear with functional endoscopic observation of tympanic membrane, acoustic immittance test middle ear pressure change, parallel middle ear cavity mucosal cell pathology examination, investigate the pathological damage characteristic and mechanism of AB;Eustachian tube pressure gauge is used to inspect the fighter pilots low pressure in different altitude and different rate of increase/decrease when the eustachian tube opening pressure, observe the dynamic changes of the eustachian tube function.By the fighter flight crew Ear pressure function(Ear pressure function EPF) of the traditional qualitative to the quantitative examination examination, for our country’s aviation medical treatment and prevention of identification with the new standards.Part one: Ear barotrauma(AB) dynamic modelThe 70 Japanese big ear rabbits were randomly divided into three groups: build module(divided into(1)- ? group), conditions, the control group and blank control group.Building modules: expansion sponge tamponade animal right nasal and nasopharyngeal, flight simulation in the process of low pressure tank increase/decrease observing animal behavior change, low pressure tank before and after the increase/decrease with functional ear speculum observation of the right ear,acoustic immittance measurement right middle ear pressure, put to death animals right middle ear mucosa cell pathology examination.Low pressure tank increase/decreasesolutions include:(1), respectively, with the increased rate of different(100 m/s, 75m/s, 50 meters/seconds) up to 4 km altitude or 2 km altitude, for 5 minutes, to 15 m/s descent rate fell to the ground, repeatedly run 3 times;The increased rate of 2 to 15m/s rise to 2 km altitude of 4 km or altitude, for 5 minutes, then at different rates(100m/s, 100 m/SEC, 50 meters/seconds) fell to the ground, repeatedly performed three times.(3) to 15 m/s rate up to 4 km altitude, stay five minutes, with 15 m/s rate fell to the ground, repeatedly performs lifting three times.Conditions in the control group:build module animals left ear.Blank control group: animals into low pressure tank, do not increase/decrease, animal placement time and making a module- ? low pressure tank increase/decrease time, same the right ear was observed.The rank and inspection,statistical analysis of different speed and different height of animal behavior change,the degree of tympanic membrane hyperemia, middle ear pressure changes and pathological injury of middle ear mucosa cells.Results showed that:(1) making a module- ? group animal characteristic in AB behavior changes, especially in the altitude is below 2 km.Diction created module functional endoscopy, acoustic immittance examination prompt AB, especially in the 100 m/s when the rising/falling the most obvious.(3) building module loss of middle ear was observed in all the middle ear mucosa cilia, inflammatory cells infiltration and inflammatory cells within the glandular lumens are known as effusion, 100 meters per second is 75 meters per second and 50 meters/seconds when the elevator is more serious.Conclusion: the low pressure tank caused by flight simulation animal AB, tympanic membrane hyperemia or perforation, middle ear tympanic cavity pressure and the change of cell morphology, serious situation of the damage and flight lift rate is gradually increasing,and the most prominent in the 2 km altitude below.Part two: Flight crew ear pressure function evaluation researchCollecting, sorting and statistical analysis of 90 cases(180 ears) modified medical fighter pilots.Results:(1) the pilot ground eustachian tube opening pressure normal range of 8 to 40 mbar(average 20.79 mbar);(2) low pressure tank up to 2 km,pilots around the ear of the eustachian tube opening pressure were 19.90 ± 2.245 mbar and 20.00± 2.317 mbar, significantly lower than the low pressure tank fell to 2 km respectively was 22.20 ± 4.491 mbar and 21.65± 2.183 mbar open pressure, t value were 2.623 and 4.134, all p < 0.05;(3) low pressure tank by the same height 4 km down to 2 km, declining rate of 20 m/s pilots around the ear of the eustachian tubeopening pressure were 18.10 ±4.303 mbar and 17.80 ± 3.955 mbar, obviously declining rate of less than 30 m/s "were 22.20 ± 4.491 mbar and 21.65 ± 2.183 mbar open pressure, t value were 2.948 and 3.811, p < 0.05).Conclusion: when the eustachian tube opening pressure in flight than rises;Rapid decline of the eustachian tube opening pressure higher than slow down.This research through the establishment of the AB dynamic model and the dynamic of fighter pilots eustachian tube machine can study, further deepening the understanding of AB pathogenesis and damage characteristics, obtained the pilot of the eustachian tube opening pressure normal and its influencing factors, for AB will provide referential basis for the prevention and control measures and medical evaluation. |
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