Analysis of electrode impedance and its subcomponents for lateral wall, mid-scala, and perimodiolar electrodes in cochlear implants

2021 ◽  
pp. 1-8
Author(s):  
Aniket A. Saoji ◽  
Madison Graham ◽  
Amy Stein ◽  
Kanthaiah Koka
Keyword(s):  
Cochlear Implants ◽  
Lateral Wall ◽  
Electrode Impedance

Postoperative dynamics of electrode impedance changes in children with cochlear implants

2020 ◽  
Vol 85 (5) ◽  
pp. 29
Author(s):  
D.K. Kechiyan ◽  
V.V. Bakhshinyan ◽  
G.A. Tavartkiladze
Keyword(s):  
Cochlear Implants ◽  
Electrode Impedance

Hearing Preservation Cochlear Implants: A Review of Potential Mechanisms of Hearing Loss After Implantation

2017 ◽  
Vol 2 (6) ◽  
pp. 54-63
Author(s):  
Conor Kelly ◽  
Lina A. J. Reiss
Keyword(s):  
Hearing Loss ◽  
Cochlear Implants ◽  
High Frequency ◽  
Music Perception ◽  
Low Frequency ◽  
Lateral Wall ◽  
Hearing Preservation ◽  
Acoustic Stimulation ◽  
Residual Hearing ◽  
Wide Range

Hearing preservation cochlear implants (CIs) are specifically designed to preserve residual low-frequency acoustic hearing for use together with electrically stimulated high-frequency hearing. This combined electro-acoustic stimulation (EAS) provides a promising treatment option for patients with severe high-frequency hearing loss, but with some residual low-frequency hearing, and has been shown to improve speech perception, especially in background noise, music perception, and sound source localization. Thus, preservation of residual hearing should be a priority in treatment. Although residual low-frequency hearing is successfully preserved to varying degrees in many patients, some patients experience a loss of residual hearing following implantation. A wide range of potential causes of, or contributors to, loss of residual hearing in EAS CI users have been proposed. In this paper, we review the evidence for several of the proposed causes of hearing loss with EAS CI. We conclude that its etiology is likely a multifactorial, heterogeneous phenomenon. Furthermore, we suggest that studies to further elucidate effects of ischemia on lateral wall function and maintenance of endocochlear potential in the context of EAS CI implantation and use are needed.

scholarly journals Long-term electrode impedance changes and failure prevalence in cochlear implants

2015 ◽  
Vol 54 (7) ◽  
pp. 453-460 ◽  
Author(s):  
Carrie Newbold ◽  
Frank Risi ◽  
Rodney Hollow ◽  
Yusmeera Yusof ◽  
Richard Dowell
Keyword(s):  
Cochlear Implants ◽  
Electrode Impedance

Variations in Microanatomy of the Human Modiolus: Implications for Cochlear Implants

2021 ◽  
Author(s):  
Markus Pietsch ◽  
Daniel Schurzig ◽  
Rolf Salcher ◽  
Athanasia Warnecke ◽  
Peter Erfurt ◽  
...  
Keyword(s):  
Cochlear Implants ◽  
Spiral Ganglion ◽  
Lateral Wall ◽  
Cone Beam ◽  
Corrosion Casts ◽  
Common Cause ◽  
Human Cochlea ◽  
Vascular Structures ◽  
Cochlear Morphology ◽  
The Individual

Abstract Human cochlear anatomy is highly variable. The phenomenon has been first described qualitatively, followed by a quantitative variability assessment with detailed anatomical models of the human cochlea. However, all previous work focused on lateral cochlear wall. Few information is available on the variability of the modiolar wall. Modiolar variability, likely determined by variability in the spiral ganglion, provides key information on when during ontogenesis the individual cochlear morphology is established: before and/or after neuronal structures are formed. In the present study we analyzed 108 corrosion casts, 95 clinical cone beam computer tomographies and 15 µCTs of human cochleae and observed modiolar variability of similar and larger extent than the lateral wall variability. Lateral wall measures correlated with modiolar wall measures significantly. ~49% of the variability has a common cause, very likely established already during the time when the spiral ganglion is formed. Proximity of other neuronal and vascular structures, defining the remaining variability in scalar spaces, are determined later in ontogenesis, when the scalae are formed. The present data further allows implications for perimodiolar cochlear implants and their tip fold-overs. In particular, the data demonstrate that tip fold-overs of preformed implants likely result from the morphology of the modiolus (with radius changing from base to apex), and that optimal cochlear implantation of perimodiolar arrays cannot be guaranteed without an individualized surgical technique.

scholarly journals Effect of initial switch-on within 24 hours of cochlear implantation using slim modiolar electrodes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Woongsang Sunwoo ◽  
Hyoung Won Jeon ◽  
Byung Yoon Choi
Keyword(s):  
Cohort Study ◽  
Cochlear Implants ◽  
Retrospective Cohort Study ◽  
Cochlear Implantation ◽  
Retrospective Cohort ◽  
Electrode Array ◽  
Electrode Impedance ◽  
Post Operation ◽  
Lower Impedance ◽  
Conventional Switch

AbstractReducing electrode impedance is an important factor in improving the functional benefits of cochlear implants (CIs). The immediate effect of early switch-on within 24 h of surgery on impedance among CI recipients with various types of electrodes has been reported previously; however, the immediate change and the evolution of electrode impedances of slim modiolar electrodes after early switch-on within 24 h of implantation has not. Therefore, the focus of this retrospective cohort study of CI patients was to compare the effect of early switch-on (n = 36) and conventional switch-on (n = 72) 2–4 weeks post-operation on impedance. Compared with impedance measured intraoperatively, our results demonstrate a significant decrease in impedance from 11.5 to 8.9 kΩ (p < 0.001) at 2–4 weeks after implantation in the early switch-on group, which sharply contrasted with elevated impedance values for conventional switch-on 2–4 weeks after implantation (from 10.7 to 14.2 kΩ, p = 0.001). Notably, a comparatively lower impedance than the conventional switch-on protocol was observed for up to 2 months post-operation. Most importantly, a much earlier stabilization of impedance can be achieved with the early switch-on protocol coupled with the slim modiolar electrode array compared to the conventional switch-on protocol, offering the advantage of reducing the number of required mapping sessions in the early stages of rehabilitation.

scholarly journals Effect of Initial Switch-On Within 24 Hours of Cochlear Implantation Using Slim Modiolar Electrodes: Potential Clinical Implications

2021 ◽  
Author(s):  
Woongsang Sunwoo ◽  
Hyoung Won Jeon ◽  
Byung Yoon Choi
Keyword(s):  
Cochlear Implants ◽  
Cochlear Implantation ◽  
Electrode Array ◽  
Clinical Implications ◽  
Electrode Impedance ◽  
Significant Drop ◽  
Early Stages ◽  
Post Operation ◽  
Lower Impedance ◽  
Conventional Switch

Abstract Reducing electrode impedance is an important factor in improving the functional benefits of cochlear implants (CIs). The immediate effect of early switch-on within 24 hours of surgery on impedance among CI recipients with various types of electrodes has been reported previously; however, the immediate change and the evolution of electrode impedances of slim modiolar electrodes after early switch-on within 24 hours of implantation has not. Therefore, the focus of this study was to compare the effect of early switch-on and conventional switch-on 3–4 weeks post-operation on impedance. Compared with impedance measured intraoperatively, our results demonstrate a significant drop in impedance for early switch-on, which sharply contrasted with elevated impedance values for conventional switch-on 3–4 weeks after implantation. Notably, a comparatively lower impedance than the conventional switch-on protocol was observed for up to 2 months post-operation. Most importantly, a much earlier stabilization of impedance can be achieved with the early switch-on protocol coupled with the slim modiolar electrode array compared to the conventional switch-on protocol, offering the advantage of reducing the number of required mapping sessions in the early stages of rehabilitation.

Effects of Fundamental Frequency Contours on Sentence Recognition in Mandarin-Speaking Children With Cochlear Implants

2020 ◽  
Vol 63 (11) ◽  
pp. 3855-3864
Author(s):  
Wanting Huang ◽  
Lena L. N. Wong ◽  
Fei Chen ◽  
Haihong Liu ◽  
Wei Liang
Keyword(s):  
Cochlear Implants ◽  
Fundamental Frequency ◽  
Signal To Noise Ratio ◽  
Lexical Tone ◽  
Signal To Noise ◽  
Sentence Recognition ◽  
Test Conditions ◽  
Age Appropriate ◽  
F0 Contour ◽  
Appropriate Sentences

Purpose Fundamental frequency (F0) is the primary acoustic cue for lexical tone perception in tonal languages but is processed in a limited way in cochlear implant (CI) systems. The aim of this study was to evaluate the importance of F0 contours in sentence recognition in Mandarin-speaking children with CIs and find out whether it is similar to/different from that in age-matched normal-hearing (NH) peers. Method Age-appropriate sentences, with F0 contours manipulated to be either natural or flattened, were randomly presented to preschool children with CIs and their age-matched peers with NH under three test conditions: in quiet, in white noise, and with competing sentences at 0 dB signal-to-noise ratio. Results The neutralization of F0 contours resulted in a significant reduction in sentence recognition. While this was seen only in noise conditions among NH children, it was observed throughout all test conditions among children with CIs. Moreover, the F0 contour-induced accuracy reduction ratios (i.e., the reduction in sentence recognition resulting from the neutralization of F0 contours compared to the normal F0 condition) were significantly greater in children with CIs than in NH children in all test conditions. Conclusions F0 contours play a major role in sentence recognition in both quiet and noise among pediatric implantees, and the contribution of the F0 contour is even more salient than that in age-matched NH children. These results also suggest that there may be differences between children with CIs and NH children in how F0 contours are processed.

Age at Full-Time Use Predicts Language Outcomes Better Than Age of Surgery in Children Who Use Cochlear Implants

2019 ◽  
Vol 28 (4) ◽  
pp. 986-992 ◽  
Author(s):  
Lisa R. Park ◽  
Erika B. Gagnon ◽  
Erin Thompson ◽  
Kevin D. Brown
Keyword(s):  
Cochlear Implants ◽  
Time Use ◽  
Expressive Language ◽  
Normal Hearing ◽  
Full Time ◽  
Language Outcomes ◽  
Age At Surgery ◽  
Device Placement ◽  
Device Use ◽  
Better Than

Purpose The aims of this study were to (a) determine a metric for describing full-time use (FTU), (b) establish whether age at FTU in children with cochlear implants (CIs) predicts language at 3 years of age better than age at surgery, and (c) describe the extent of FTU and length of time it took to establish FTU in this population. Method This retrospective analysis examined receptive and expressive language outcomes at 3 years of age for 40 children with CIs. Multiple linear regression analyses were run with age at surgery and age at FTU as predictor variables. FTU definitions included 8 hr of device use and 80% of average waking hours for a typically developing child. Descriptive statistics were used to describe the establishment and degree of FTU. Results Although 8 hr of daily wear is typically considered FTU in the literature, the 80% hearing hours percentage metric accounts for more variability in outcomes. For both receptive and expressive language, age at FTU was found to be a better predictor of outcomes than age at surgery. It took an average of 17 months for children in this cohort to establish FTU, and only 52.5% reached this milestone by the time they were 3 years old. Conclusions Children with normal hearing can access spoken language whenever they are awake, and the amount of time young children are awake increases with age. A metric that incorporates the percentage of time that children with CIs have access to sound as compared to their same-aged peers with normal hearing accounts for more variability in outcomes than using an arbitrary number of hours. Although early FTU is not possible without surgery occurring at a young age, device placement does not guarantee use and does not predict language outcomes as well as age at FTU.

Overview of Current Approaches to Aural Rehabilitation for Adults With Cochlear Implants

2020 ◽  
Vol 5 (5) ◽  
pp. 1175-1187
Author(s):  
Rachel Glade ◽  
Erin Taylor ◽  
Deborah S. Culbertson ◽  
Christin Ray
Keyword(s):  
Health Care ◽  
Clinical Practice ◽  
Cochlear Implants ◽  
Practice Patterns ◽  
The United States ◽  
Care Providers ◽  
Aural Rehabilitation ◽  
Starting Point ◽  
Clinical Models ◽  
Hearing Health

Purpose This clinical focus article provides an overview of clinical models currently being used for the provision of comprehensive aural rehabilitation (AR) for adults with cochlear implants (CIs) in the Unites States. Method Clinical AR models utilized by hearing health care providers from nine clinics across the United States were discussed with regard to interprofessional AR practice patterns in the adult CI population. The clinical models were presented in the context of existing knowledge and gaps in the literature. Future directions were proposed for optimizing the provision of AR for the adult CI patient population. Findings/Conclusions There is a general agreement that AR is an integral part of hearing health care for adults with CIs. While the provision of AR is feasible in different clinical practice settings, service delivery models are variable across hearing health care professionals and settings. AR may include interprofessional collaboration among surgeons, audiologists, and speech-language pathologists with varying roles based on the characteristics of a particular setting. Despite various existing barriers, the clinical practice patterns identified here provide a starting point toward a more standard approach to comprehensive AR for adults with CIs.

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