Although the Vibrant Soundbridge is one of the most frequently used active middle ear implants, data regarding how middle ear ventilation disorders may affect the transmission behavior of its floating mass transducer are still insufficient. Studies involving coupling the floating mass transducer to the stapes head are particularly lacking. This temporal bone study evaluated the influence of simulated middle ear ventilation disorders on the middle ear transfer function in the reconstructed middle ear. The middle ear transfer function was measured using Laser Doppler Vibrometry after vibroplasty onto the stapes head, with or without tympanic membrane reconstruction. Middle ear ventilation disorders were simulated through changes in static pressure via the external ear channel with a maximum pressure of þ3 kPa. Slice thickness of tympanic membrane reconstruction material was measured using micro-CT. When the reconstructed ossicular chain and the reconstructed tympanic membrane were mechanically excited by the floating mass transducer under conditions of ambient static pressure, the transmission behavior was found to be independent of the type of tissue used. Increase in static pressure up to þ3 kPa caused maximum low frequency transmission loss of 15 dB when elastic grafts were used and 5 dB when stiff tissue was inserted. At high frequencies, measured loss of up to 5 dB was relatively independent of the tissue stiffness. Increase in static pressure led to displacement of the tissues towards the vestibulum and caused stiffening, especially of the annular ligament. Stiffening-induced transmission losses were mainly found at low frequencies and could not be compensated by the floating mass transducer in this range. Above 1300 Hz, the continuous force spectrum of the actuator sufficiently protected against loss of amplitude. To minimize postoperative transmission loss due to persisting ventilation disorders, choosing a very stiff tympanic membrane reconstruction material seems to be appropriate.:Inhaltsverzeichnis
Abkürzungsverzeichnis V
1 Einleitung 1
1.1 Einführung 1
1.2 Operationen zur Hörverbesserung 2
1.3 Mittelohrimplantate 6
1.4 Belüftungsstörungen des Mittelohres 12
1.5 Fragestellungen, Forschungshypothesen und Zielstellung der Arbeit 18
2 Material und Methoden 20
2.1 Laserdopplervibrometrische Messungen am Felsenbeinpräparat 20
2.2 Untersuchung der Trommelfellersatzmaterialien mittels optischer Messverfahren
3 Ergebnisse 42
3.1 Ermittelung der Trommelfellersatzmaterialdicken und -steifigkeiten mittels optischer
Messverfahren 42
3.2 Messung der Mittelohrübertragungsfunktion am Felsenbeinpräparat 62
4 Diskussion 104
4.1 Bestimmung der Trommelfellersatzmaterialdicken und -steifigkeiten mittels optischer
Messverfahren 104
4.2 Messung der Mittelohrübertragungsfunktion am Felsenbeinpräparat 110
4.3 Ausblick und Konsequenzen der Untersuchungen zur Paukenminderbelüftung auf die
Vibroplastik und die Tympanoplastik Typ III 131
4.4 Funktionelles Hörergebnis nach Implantation einer VSB beim Vorliegen einer Schallleitungsschwerhörigkeit
oder kombinierten Schwerhörigkeit 133
4.5 Schlussfolgerung 134
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:76873 |
| Date | 08 December 2021 |
| Creators | Müller, Christoph Daniel |
| Contributors | Zahnert, Thomas, Mlynski, Robert, Technische Universität Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | German |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
Page generated in 0.0019 seconds