Overview of the Hannover Program Using the Nucleus Device

1987 ◽  
Vol 96 (1_suppl) ◽  
pp. 129-132 ◽  
Author(s):  
R. D. Battmer ◽  
E. Lehnhardt ◽  
R. Laszig
Keyword(s):  
Cochlear Implants ◽  
Hair Cells ◽  
Qualitative Data ◽  
Dynamic Range ◽  
Single Channel ◽  
Electrode Array ◽  
Speech Processor ◽  
The Status ◽  
Operation Results ◽  
Speech Tracking

Successful implantation of a cochlear implant requires a healthy auditory nerve. Subjective and qualitative data can be obtained by means of promontory testing (PT). Cochlear microphonics (CM) in electrocochleography, on the other hand, gives information about the status of the hair cells in the inner ear. The results of both tests together can indicate the feasibility of an implant in cases of sensory deafness (PT positive, no CM), while other combinations help to localize the origin of the deafness, eg, neural or sensorineural. Therefore, the reliability of results is extensive and almost doubly guaranteed. To answer the question of using single-channel or multichannel cochlear implants we decided to use the 22-channel Nucleus device. The digital working system consists of the implanted receiver-stimulator and external speech processor. To date we have implanted 14 patients. In all of them, the electrode array could be inserted easily, and the threshold and comfortable levels could be adjusted very fast. The dynamic range showed a growth in the first weeks after the operation. Results of 11 of our patients are presented. They show that 1) speech-tracking scores with the processor are much higher than with lipreading only; 2) lipreading ability remains constant; 3) the understanding of vowels and consonants with the speech processor is much better; and 4) three of our patients reached scores between 20 and 30 words per minute with hearing alone for speech tracking.

Electrode complications in 100 adults with multichannel cochlear implants

1999 ◽  
Vol 113 (24) ◽  
pp. 18-20 ◽  
Author(s):  
R. L. Stoddart ◽  
H. R. Cooper
Keyword(s):  
Facial Nerve ◽  
Cochlear Implants ◽  
Nerve Stimulation ◽  
Dynamic Range ◽  
Electrode Array ◽  
Poor Performance ◽  
Sound Quality ◽  
Cochlear Damage ◽  
Facial Nerve Stimulation ◽  
Loudness Growth

AbstractAt switch-on (first post-operative stimulation of the implant) and during subsequent reprogramming, electrodes can, in some patients, be found to be non-functional or to be performing sub-optimally for a number of reasons. This paper examines the reasons for the poor performance of these electrodes by means of a retrospective analysis of 100 patient records. All of these patients received the Nucleus multichannel device.The most common reason for an electrode to require de-activation was found to be facial nerve stimulation, with poor sound quality and pain also being very common. Other reasons included absence of auditory stimulation, vibration, reduced dynamic range, throat sensations, absence of loudness growth or dizziness. The occurrence of these reasons along the electrode array was examined, more basal electrodes being found to be non-functional as a result of having a small dynamic range or poor sound quality. Pain and vibration were found to occur throughout the array and the more apical electrodes were found to be non-functional as a result of facial nerve stimulation. It is suggested that the electrodes at the basal end of the array are likely to be extra-cochlear or are at the site of the most cochlear damage, whereas the more apical electrodes lie in closer proximity to the facial nerve.

Selecting the Optimal FM System for Children With Cochlear Implants

2008 ◽  
Vol 18 (1) ◽  
pp. 19-24
Author(s):  
Erin C. Schafer
Keyword(s):  
Speech Recognition ◽  
Cochlear Implants ◽  
Empirical Research ◽  
Background Noise ◽  
Signal To Noise Ratio ◽  
Evidence Based ◽  
Signal To Noise ◽  
Speech Processor ◽  
System Input ◽  
Optimal Type

Children who use cochlear implants experience significant difficulty hearing speech in the presence of background noise, such as in the classroom. To address these difficulties, audiologists often recommend frequency-modulated (FM) systems for children with cochlear implants. The purpose of this article is to examine current empirical research in the area of FM systems and cochlear implants. Discussion topics will include selecting the optimal type of FM receiver, benefits of binaural FM-system input, importance of DAI receiver-gain settings, and effects of speech-processor programming on speech recognition. FM systems significantly improve the signal-to-noise ratio at the child's ear through the use of three types of FM receivers: mounted speakers, desktop speakers, or direct-audio input (DAI). This discussion will aid audiologists in making evidence-based recommendations for children using cochlear implants and FM systems.

Application of Advanced Technologies in Natural Product Research: A Review with Special Emphasis on ADMET Profiling

2020 ◽  
Vol 21 (10) ◽  
pp. 751-767
Author(s):  
Pobitra Borah ◽  
Sangeeta Hazarika ◽  
Satyendra Deka ◽  
Katharigatta N. Venugopala ◽  
Anroop B. Nair ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Natural Product ◽  
Dynamic Range ◽  
Early Stage ◽  
Attrition Rate ◽  
Drug Candidates ◽  
Advanced Technologies ◽  
Natural Product Research ◽  
The Status ◽  
Safety Parameters

The successful conversion of natural products (NPs) into lead compounds and novel pharmacophores has emboldened the researchers to harness the drug discovery process with a lot more enthusiasm. However, forfeit of bioactive NPs resulting from an overabundance of metabolites and their wide dynamic range have created the bottleneck in NP researches. Similarly, the existence of multidimensional challenges, including the evaluation of pharmacokinetics, pharmacodynamics, and safety parameters, has been a concerning issue. Advancement of technology has brought the evolution of traditional natural product researches into the computer-based assessment exhibiting pretentious remarks about their efficiency in drug discovery. The early attention to the quality of the NPs may reduce the attrition rate of drug candidates by parallel assessment of ADMET profiling. This article reviews the status, challenges, opportunities, and integration of advanced technologies in natural product research. Indeed, emphasis will be laid on the current and futuristic direction towards the application of newer technologies in early-stage ADMET profiling of bioactive moieties from the natural sources. It can be expected that combinatorial approaches in ADMET profiling will fortify the natural product-based drug discovery in the near future.

Implantable hearing interfaces

2018 ◽  
Author(s):  
Torsten Lehmann ◽  
André van Schaik
Keyword(s):  
Cochlear Implants ◽  
Neural Activity ◽  
Dynamic Range ◽  
Systems Design ◽  
Fundamental Operation ◽  
Profound Hearing Loss ◽  
Biomedical Implant ◽  
Dynamic Range Compression ◽  
Hearing Function ◽  
Key Aspects

The chapter Implantable hearing interfaces describes the fundamental operation of a commonly available biohybrid system, the cochlear implant, or bionic ear. This neuro-stimulating biomedical implant is very successful in restoring hearing function to people with profound hearing loss. The fundamental operation of the biological cochlea is described and parallels are drawn between key aspects of the biological system and the biohybrid implementation: dynamic range compression, translation of sound to neural activity, and tonotopic mapping. Critical considerations are discussed for simultaneously meeting biological, surgical, and engineering restrictions in successful biohybrid systems design. Finally, challenges in present and future cochlear implants are outlined and directions of current research given.

scholarly journals Activation and Two Modes of Blockade by Strontium of Ca2+-activated K+ Channels in Goldfish Saccular Hair Cells

1998 ◽  
Vol 111 (2) ◽  
pp. 363-379 ◽  
Author(s):  
Izumi Sugihara
Keyword(s):  
Dissociation Constant ◽  
Time Constant ◽  
Hair Cells ◽  
Single Channel ◽  
Hill Coefficient ◽  
K Channels ◽  
Voltage Dependent ◽  
Time Courses ◽  
The Hill ◽  
Inside Out

Effects of internal Sr2+ on the activity of large-conductance Ca2+-activated K+ channels were studied in inside-out membrane patches from goldfish saccular hair cells. Sr2+ was approximately one-fourth as potent as Ca2+ in activating these channels. Although the Hill coefficient for Sr2+ was smaller than that for Ca2+, maximum open-state probability, voltage dependence, steady state gating kinetics, and time courses of activation and deactivation of the channel were very similar under the presence of equipotent concentrations of Ca2+ and Sr2+. This suggests that voltage-dependent activation is partially independent of the ligand. Internal Sr2+ at higher concentrations (>100 μM) produced fast and slow blockade both concentration and voltage dependently. The reduction in single-channel amplitude (fast blockade) could be fitted with a modified Woodhull equation that incorporated the Hill coefficient. The dissociation constant at 0 mV, the Hill coefficient, and zd (a product of the charge of the blocking ion and the fraction of the voltage difference at the binding site from the inside) in this equation were 58–209 mM, 0.69–0.75, 0.45–0.51, respectively (n = 4). Long shut events (slow blockade) produced by Sr2+ lasted ∼10–200 ms and could be fitted with single-exponential curves (time constant, τl−s) in shut-time histograms. Durations of burst events, periods intercalated by long shut events, could also be fitted with single exponentials (time constant, τb). A significant decrease in τb and no large changes in τl−s were observed with increased Sr2+ concentration and voltage. These findings on slow blockade could be approximated by a model in which single Sr2+ ions bind to a blocking site within the channel pore beyond the energy barrier from the inside, as proposed for Ba2+ blockade. The dissociation constant at 0 mV and zd in the Woodhull equation for this model were 36–150 mM and 1–1.8, respectively (n = 3).

scholarly journals Two New Directions in Speech Processor Design for Cochlear Implants

2005 ◽  
Vol 26 (Supplement) ◽  
pp. 73S-81S ◽  
Author(s):  
Blake S. Wilson ◽  
Reinhold Schatzer ◽  
Enrique A. Lopez-Poveda ◽  
Xiaoan Sun ◽  
Dewey T. Lawson ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Processor Design ◽  
Speech Processor ◽  
New Directions

Effect of Speech Processor Program Modifications on Cochlear Implant Recipients’ Threshold and Maximum Acceptable Loudness Levels

1999 ◽  
Vol 8 (2) ◽  
pp. 128-136 ◽  
Author(s):  
John C. Sun ◽  
Margarate W. Skinner ◽  
S. Y. Liu ◽  
T. S. Huang
Keyword(s):  
Electrical Stimulation ◽  
Cochlear Implant ◽  
Everyday Life ◽  
Dynamic Range ◽  
Active Electrode ◽  
Speech Processor ◽  
Significant Change ◽  
Upper Boundary

This study’s purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients’ thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants’ threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Uses of content analysis in economic sciences: An overview of the current situation and prospects

2021 ◽  
pp. 79-95
Author(s):  
A. N. Oleinik
Keyword(s):  
Content Analysis ◽  
Mixed Methods ◽  
Qualitative Data ◽  
Web Of Science ◽  
Current Situation ◽  
Economic Information ◽  
The Status ◽  
On Line ◽  
The Creation

The article discusses the status of quantitative and qualitative data in economic sciences, as well as methods for transforming data into information and knowledge. Particular attention is devoted to content analysis as a set of methods for aggregating, processing and analyzing qualitative data; its forms (qualitative, quantitative and mixed methods) and uses by economists. Content analysis appears to be particularly suitable for non-orthodox economists because of their refusal to consider price as the only source of economic information. The content analysis of metadata of articles indexed in Web of Science and eLibrary suggests that Russian economists still have insufficient familiarity with the principles of content analysis and their applications to research compared with their Western counterparts. It is argued that the creation of on-line platforms for content analysis and on-line banks of qualitative data may become a trigger for changing this situation.

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