1,721,076 research outputs found
Multidisciplinary Approaches toward an Improved Efficacy of Cochlear Implants
Full text linkThe cochlear implant (CI) is an auditory prosthesis that electrically stimulates the cochlear nerve to restore hearing. Although modern CI systems have proven to be a successful treatment for hearing impaired or deaf people, there are significant differences in the performance between people with normal hearing and CI recipients. This thesis aims to contribute to the field of cochlear implantation with a multidisciplinary approach, addressing problems related to minimally invasive surgical implantation and front-end processing of CI audio processors.
First, concepts required for the clinical application of a minimally invasive robotic cochlear implantation approach were investigated. A computer-assisted method for scala tympani access and insertion
trajectory planning was developed and evaluated in ex vivo models. With the proposed method, it was possible to achieve full scala tympani insertions in cases demanding a trajectory positioning accuracy below 0.5 mm. The study demonstrated that an optimal access to the scala tympani can be planned and performed with the robotic system.
Furthermore, a manual insertion procedure for the minimally invasive approach was developed and tested. In all 8 tested specimens it was possible to insert the CI electrode arrays through the small drill tunnel using the proposed procedure, showing the feasibility of the approach.
Second, front-end processing strategies of novel CI audio processors were evaluated. The influence of the microphone position of a single-unit processor on speech intelligibility in noise was investigated
in a clinical study with 12 experienced CI users. It was shown that detrimental effects on speech reception are introduced by microphones positioned further to the back of the head. The signal-to-noise ratio was significantly better with the behind-the-ear processor when compared with the single-unit processor, if noise was presented from behind (4.4 dB, p <0.001). Directional microphone systems could be applied to overcome this drawback. A second audiological study with 10 subjects evaluated the expected benefit of a pinna effect imitating directional microphone system. The directional microphone setting improved the speech reception thresholds by up to 3.6 dB (p <0.01)
on average when compared to the omnidirectional mode, indicating that CI users can benefit from the directional microphone system
Planung, Navigation und Robotik in der Hörimplantologie
No full textDie digitalisierte Medizin bietet großes Potenzial, um Eingriffe schonender und präziser durchführen zu können. Auch in der Hörimplantologie haben moderne Planungs- und Navigationsverfahren sowie roboterbasierte Assistenzsysteme in den letzten Jahren Einzug genommen. Durch den Einsatz dieser Systeme erhoffen sich Experten verbesserte chirurgische und audiologische Behandlungsergebnisse bei den Patienten
Long term benefit of bone anchored hearing systems in single sided deafness.
No full textCONCLUSION
Bone Anchored Hearing Systems (BAHS) can be expected to still be used by ∼85% of patients with single sided deafness (SSD) 5 years after implantation, and by ∼50% after 10 years.
OBJECTIVES
To investigate the long-term use of BAHS and the reasons to stop.
METHOD
This was a retrospective chart review of all 33 German speaking adults with SSD who had been implanted with a BAHS at one center and of whom the implant status and use of the BAHS were known.
RESULTS
Ranging from 2.6-12.3 years after BAHS implantation, 21 implantees (63.6%) were still using their device (average use = 7.9 years). Seven (21.2%) had stopped using their BAHS because of insufficient benefit (audiologic reasons). The subjective assessment of the benefit of the BAHS differs significantly from the users. Five former users (15.2%) became non-users for reasons unrelated to their hearing performance, namely infections, implant loss, difficulties with the handling, or aesthetic reasons
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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