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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Erfassung der intraoperativen Ankopplungseffizienz mittels evozierten Potentialen bei mit Mittelohrimplantat versorgten Patienten / Determining the intraoperative coupling efficiency using evoked potentials in middle ear implant patients

Geiger, Ute January 2021 (has links) (PDF)
Patienten mit leicht bis hochgradigen Schallleitungs-, Schallempfindungs- und kombinierten Schwerhörigkeiten werden routinemäßig nach erfolglosem Hörgerätetrageversuch mit aktiven Mittelohrimplantaten versorgt. Aktive Mittelohrimplantate können an verschiedene Strukturen des Mittelohrs angekoppelt werden. Der Ort der Ankopplung ist abhängig vom Hörverlust und der individuellen Physiologie des Mittelohres. Die Hörverbesserung ist dabei stark von der Kopplungseffizienz des Implantatwandlers an die Mittelohrstruktur abhängig. Aktuell gibt es keine zufriedenstellende Möglichkeit die Kopplungseffizienz intraoperativ zu bestimmen. Daher wird eine objektive Methode eingeführt, um intraoperativ auditorische Hirnstammantworten (BERAs) bei Stimulation über das Implantat abzuleiten. Die Vibrant Soundbrigde® (VSB) wird dabei mit einem Drahtlosüberträger (miniTEK, Signia GmbH, Erlangen) und der Carina®-Aktuator über ein Audiokabel mit der BERA-Anlage verbunden. Die BERA-Anlage überträgt die Stimuli direkt an das Implantat, welches an die Mittelohrstruktur angekoppelt ist. Die BERA-Antworten werden bei der VSB durch einen optimierten VSB-CE-Chirp und beim Carina®-System durch den Standard CE-Chirp evoziert, beginnend bei Pegeln oberhalb der Knochenleitungshörschwelle bis unter die Registrierungsschwelle. Diese Methode kann die intraoperative Integrität des Implantats sowie die Kopplungseffizienz bestimmen, um eine Aussage über den zu erwartenden Hörerfolg treffen zu können. Darüber hinaus kann die versorgte Hörschwelle verwendet werden, um die Anpassung bei Kindern oder schwierigen Fällen zu unterstützen und um eine Hörverschlechterung über die Zeit zu erfassen. Zusammenfassend, konnte eine Methode zur Bestimmung der intraoperativen Kopplungseffizienz während der Implantation von VSBs und Carinas® etabliert werden. Darüber hinaus werden intraoperative BERA-Daten von 30 VSB- und 10-Carina®-Patienten sowie deren Hörergebnisse gezeigt. / Patients with mild to severe air conduction, bone conduction or combined hearing loss are treated routinely with active middle ear implants after unsuccessful hearing aid trials. Active middle ear implants are surgically coupled to different structures of the middle ear, depending on the hearing loss and the individual physiology of the middle ear. Hearing improvement is highly dependent on the coupling of the implants transducer and the middle ear structure. Currently, there is no sufficient method to determine the coupling efficiency intraoperatively. For this application a objective method was introduced to allow intraoperatively measured auditory brainstem responses (ABRs), while stimulating the patient via the implant. For this purpose the Vibrant Soundbrigde® (VSB) was coupled with a wireless streamer (miniTEK, Signia GmbH, Erlangen) or the Carina® actuator was connected via Audiocable to an ABR device. The ABR device transmits the stimuli direct to the implant, which is coupled to the middle ear structure. The ABRs are evoked by chirpsounds, using the optimized VSB-CE-Chirps (VSB) or standard CE-Chirp (Carina®) starting from levels above bone conduction thresholds to levels below threshold. These method can measure the intraoperative integrity of the implant and the coupling efficiency to avoid insufficient hearing outcomes. Furthermore, the determination of aided thresholds could be used to help fitting in children and difficult cases and could determine hearing degradation over time. Overall, a method to determine the coupling effiency intraoperatively during VSB and Carina® implantation surgeries could be established. Furthermore, intraoperative ABRdata from 30 VSB and 10 Carina® implantations and the outcomes of these patients are described.
2

Audiometrische Ergebnisse und Lebensqualität mit einem aktiven Mittelohrimplantat bei reiner Innenohrschwerhörigkeit im Vergleich zu Patienten mit konventionellen Hörgeräten / Long-term functional outcome and satisfaction of patients with an active middle ear implant for sensorineural hearing loss compared to a matched population with conventional hearing aids

Bewarder, Julian 17 March 2016 (has links)
No description available.
3

Long-Term Outcomes of Vibroplasty Coupler Implantations to Treat Mixed/Conductive Hearing Loss

Zahnert, Thomas, Mlynski, Robert, Löwenheim, Hubert, Beutner, Dirk, Hagen, Rudolf, Ernst, Arneborg, Zehlicke, Thorsten, Kühne, Hilke, Friese, Natascha, Tropitzsch, Anke, Luers, Jan Christoffer, Todt, Ingo, Hüttenbrink, Karl-Bernd 19 May 2020 (has links)
Objective: To evaluate the long-term safety and performance of four different vibroplasty couplers (round window, oval window, CliP and Bell coupler) in combination with an active middle ear implant. Methods: This was a multicentre, prospective, long-term study including 5 German hospitals. Thirty adult subjects suffering from conductive or mixed hearing loss were initially enrolled for the study, 24 of these were included in the final analysis with up to 36 months of postsurgical follow-up data. Bone conduction and air conduction were measured pre- and postoperatively to evaluate safety. Postoperative aided sound field thresholds and Freiburger monosyllable word recognition scores were compared to unaided pre-implantation results to confirm performance. Additional speech tests compared postoperative unaided with aided results. To determine patient satisfaction, an established quality-of-life questionnaire developed for conventional hearing aid usage was administered to all subjects. Results: Mean postoperative bone conduction thresholds remained stable throughout the whole study period. Mean functional gain for all couplers investigated was 38.5 ± 11.4 dB HL (12 months) and 38.8 ± 12.5 dB HL (36 months). Mean word recognition scores at 65 dB SPL increased from 2.9% in the unaided by 64.2% to 67.1% in the aided situation. The mean postoperative speech reception in quiet (or 50% understanding of words in sentences) shows a speech intelligibility improvement at 36 months of 17.8 ± 12.4 dB SPL over the unaided condition. The signal-to-noise ratio (SNR) improved by 5.9 ± 7.2 dB SNR over the unaided condition. High subjective device satisfaction was reflected by the International Inventory for Hearing Aids scored very positively. Conclusion: A significant improvement was seen with all couplers, and audiological performance did not significantly differ between 12 and 36 months after surgery.
4

Multicenter Clinical Trial of Vibroplasty Couplers to Treat Mixed/Conductive Hearing Loss: First Results

Zahnert, Thomas, Löwenheim, Hubert, Beutner, Dirk, Hagen, Rudolf, Ernst, Arneborg, Pau, Hans-Wilhelm, Zehlicke, Thorsten, Kühne, Hilke, Friese, Natascha, Tropitzsch, Anke, Lüers, Jan-Christoffer, Mlynski, Robert, Todt, Ingo, Hüttenbrink, Karl-Bernd 22 May 2020 (has links)
Objective: To evaluate the safety and effectiveness of round window (RW), oval window (OW), CliP and Bell couplers for use with an active middle ear implant. Methods: This is a multicenter, long-term, prospective trial with consecutive enrollment, involving 6 university hospitals in Germany. Bone conduction, air conduction, implant-aided warbletone thresholds and Freiburger monosyllable word recognition scores were compared with unaided preimplantation results in 28 moderate-to-profound hearing-impaired patients after 12 months of follow-up. All patients had previously undergone failed reconstruction surgeries (up to 5 or more). In a subset of patients, additional speech tests at 12 months postoperatively were used to compare the aided with the unaided condition after implantation with the processor switched off. An established quality-of-life questionnaire for hearing aids was used to determine patient satisfaction. Results: Postoperative bone conduction remained stable. Mean functional gain for all couplers was 37 dB HL (RW = 42 dB, OW = 35 dB, Bell = 38 dB, CliP = 27 dB). The mean postoperative Freiburger monosyllable score was 71% at 65 dB SPL. The postimplantation mean SRT 50 (speech reception in quiet for 50% understanding of words in sentences) improved on average by 23 dB over unaided testing and signal-to-noise ratios also improved in all patients. The International Outcome Inventory for Hearing Aids (IOI-HA) quality-of-life questionnaire was scored very positively by all patients. Conclusion: A significant improvement was seen with all couplers, and patients were satisfied with the device at 12 months postoperatively. These results demonstrate that an active implant is an advantage in achieving good hearing benefit in patients with prior failed reconstruction surgery.
5

Untersuchungen zum Einfluss der Trommelfellrekonstruktion auf das Mittelohrübertragungsverhalten nach Mittelohrrekonstruktion mit aktiven Implantaten: Simulation postoperativer Belüftungsstörungen

Müller, Christoph Daniel 08 December 2021 (has links)
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

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