Middle Ear Research Using a SQUID Magnetometer. I. Micro- and Macromechanical Selection of Polymer Materials for Artificial Tympanic Membranes

Author(s):  
W. L. C. Rutten ◽  
D. Bakker ◽  
J. H. Kuit ◽  
M. Maes ◽  
J. J. Grote
2019 ◽  
Vol 10 (45) ◽  
pp. 6091-6108 ◽  
Author(s):  
Johan M. Winne ◽  
Ludwik Leibler ◽  
Filip E. Du Prez

A selection of dynamic chemistries is highlighted, with a focus on the reaction mechanisms of molecular network rearrangements, and on how mechanistic profiles can be related to the mechanical and physicochemical properties of polymer materials.


IEEE Access ◽  
2020 ◽  
Vol 8 ◽  
pp. 78622-78629 ◽  
Author(s):  
Zbigniew Kusznierewicz ◽  
Marcin Michalowski ◽  
Sergiusz Luczak ◽  
Karol Baginski ◽  
Blazej Kabzinski ◽  
...  

1995 ◽  
Vol 104 (8) ◽  
pp. 625-632 ◽  
Author(s):  
Cecilia Mattsson ◽  
Karin Magnuson ◽  
Sten Hellström

The purpose of this study was to elucidate possible relationships between the oxygen concentration of the middle ear cavity and the development of myringosclerosis. Three groups of rats with myringotomized tympanic membranes were exposed to different oxygen concentrations of 10%, 15%, and 40%, respectively, for 1 week. A fourth group was kept in ambient air. Two other groups of rats with myringotomized and intubated tympanic membranes were exposed to oxygen concentrations of 10% and 40%, respectively, for the same period of time. Otomicroscopically, all hyperoxic animals had more numerous myringosclerotic lesions compared with the ambient air group, and also displayed a pronounced hyperplasia of the keratinizing epithelium around the perforation border. By contrast, the hypoxic animals showed less pronounced myringosclerotic lesions or even completely lacked them. It is inferred that an increased oxygen concentration in the middle ear cavity will increase the likelihood of myringosclerotic deposits. The mechanism involved could be related to the formation of oxygen radicals.


1996 ◽  
Vol 105 (3) ◽  
pp. 226-233 ◽  
Author(s):  
Bruce M. Wenig

Five cases of schneiderian-type mucosal papillomas arising in the middle ear space are reported. The patients were all women, ranging in age from 19 to 57 years (median, 31 years). Clinical complaints — unilateral conductive hearing loss, pain, or otorrhea — ranged from those lasting several months to recurrent problems spanning 20 years. All of the patients had a history of chronic otitis media predating the development of the papillomas; none of the patients had a history of sinonasal or nasopharyngeal schneiderian-type papillomas. Clinically, three patients had intact tympanic membranes, while the other two patients had perforated tympanic membranes through which a bulging polypoid mass was identified. Radiographic studies showed opacification of the middle ear space without evidence of osseous destruction. The intraoperative findings were of polypoid lesions filling the middle ear space, including involvement of the eustachian tube orifice. Histologically, the tumors were identical to sinonasal schneiderian papillomas. Immunohistochemical evaluation for human papillomavirus was negative. Surgical excision is the treatment of choice. In four of the patients, recurrent tumor was identified, necessitating additional surgery. In only one patient did the initial surgery result in complete ablation of the tumor. All patients are alive and free of recurrent disease over periods ranging from 6 months to 120 months (median, 84 months).


2020 ◽  
pp. 5-13
Author(s):  
D. M. Los' ◽  
V. M. Shapovalov ◽  
S. V. Zotov

The article analyzes the use of polymer materials for solving problems of theoretical and practical medicine. The effectiveness of the use of polymers in reconstructive cardiac surgery, radiation therapy, etc. has been shown. The basic requirements set for polymers and composites for medical devices have been identified. The most important criterion for the selection of polymers is the safety of their use in clinical practice and their ability to biodegrade when they enter a living organism along the usual metabolic pathways in the absence of inflammatory and allergic reactions of surrounding tissues during longterm followup care.


1970 ◽  
Vol 13 (2) ◽  
pp. 317-325 ◽  
Author(s):  
Kenneth S. Burke ◽  
Thomas C. Nilges ◽  
Gretchen B. Henry

The middle ear impedance of a group of 25 subjects with normal middle ears was studied with the Zwislocki acoustic bridge. The basis for selection of test ears was carefully documented. Average and range of impedance measures were compared to recent data. The effects on impedance readings of operator error in the preliminary measurement of canal volume were also studied.


2013 ◽  
Vol 55 (7) ◽  
pp. 895-911 ◽  
Author(s):  
Henning Frenzel ◽  
Georg Sprinzl ◽  
Gerlig Widmann ◽  
Dirk Petersen ◽  
Barbara Wollenberg ◽  
...  

1978 ◽  
Vol 87 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Karl H. Siedentop ◽  
Arthur Loewy ◽  
Rosemary A. Corrigan ◽  
Stan B. Osenar

On 15 normal ears and 14 pathological ears of adults with intact tympanic membranes, Eustachian tube function was measured by using tympanometry in an effort to reproduce the results published by Holmquist. His method appeared to be a promising tool for clinical determination of Eustachian tube function. However, our results on normal ears were not significantly different from our results on pathological ears and were inconsistent with Holmquist's results. In contrast to Holmquist, 60% of our normal ears were unable to attain achieved negative middle ear pressures of —100 mm to —250 mm H2O. Our normal ears, as well as our pathological ears, required repeated swallows to normalize negative pressure. Tests in both our groups were not always repeatable even though recorded applied nasopharyngeal pressure was identical. Therefore, our findings do not substantiate this procedure as a useful, reliable clinical tool for measuring Eustachian tube function on ears with intact tympanic membranes.


2011 ◽  
Vol 2011 ◽  
pp. 1-4 ◽  
Author(s):  
Fehim Findik

A case study on the selection of materials for eye lenses is reported by means of Ashby's materials selection diagrams. In this study, 6 polymer materials of PMMA, PC, PS, PVC, PET, and PA are reviewed and their properties are found from the selection diagrams of Ashby and compared in a table. The final results confirmed that PMMA (acrylic) is the best material for eye lenses. The outcome also showed that the present material is environmental friendly being nontoxic and recyclable.


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