Using Evoked Compound Action Potentials to Assess Activation of Electrodes and Predict C-Levels in the Tempo+ Cochlear Implant Speech Processor

2010 ◽  
Vol 31 (1) ◽  
pp. 134-145 ◽  
Author(s):  
Isaac Alvarez ◽  
Angel de la Torre ◽  
Manuel Sainz ◽  
Cristina Roldán ◽  
Hansjoerg Schoesser ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Action Potentials ◽  
Speech Processor ◽  
Compound Action Potentials ◽  
Compound Action

scholarly journals Comparison of Electrically Evoked Compound Action Potential Thresholds and Loudness Estimates for the Stimuli Used to Program the Advanced Bionics Cochlear Implant

2010 ◽  
Vol 21 (01) ◽  
pp. 016-027 ◽  
Author(s):  
Eun Kyung Jeon ◽  
Carolyn J. Brown ◽  
Christine P. Etler ◽  
Sara O'Brien ◽  
Li-Kuei Chiou ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Dynamic Range ◽  
Compound Action Potential ◽  
Behavioral Measures ◽  
Speech Processor ◽  
Compound Action Potentials ◽  
Evoked Compound Action Potential ◽  
The Individual ◽  
The Relationship ◽  
Compound Action

Background: In the mid-1990s, Cochlear Corporation introduced a cochlear implant (CI) to the market that was equipped with hardware that made it possible to record electrically evoked compound action potentials (ECAPs) from CI users of all ages. Over the course of the next decade, many studies were published that compared ECAP thresholds with levels used to program the speech processor of the Nucleus CI. In 2001 Advanced Bionics Corporation introduced the Clarion CII cochlear implant (the Clarion CII internal device is also known as the CII Bionic Ear). This cochlear implant was also equipped with a system that allowed measurement of the ECAP. While a great deal is known about how ECAP thresholds compare with the levels used to program the speech processor of the Nucleus CI, relatively few studies have reported comparisons between ECAP thresholds and the levels used to program the speech processor of the Advanced Bionics CI. Purpose: To explore the relationship between ECAP thresholds and behavioral measures of perceptual dynamic range for the range of stimuli commonly used to program the speech processor of the Advanced Bionics CI. Research Design: This prospective and experimental study uses correlational and descriptive statistics to define the relationship between ECAP thresholds and perceptual dynamic range measures. Study Sample: Twelve postlingually deafened adults participated in this study. All were experienced users of the Advanced Bionics CI system. Data Collection and Analysis: ECAP thresholds were recorded using the commercially available SoundWave software. Perceptual measures of threshold (T-level), most comfortable level (M-level), and maximum comfortable level (C-level) were obtained using both “tone bursts” and “speech bursts.” The relationship between these perceptual and electrophysiological variables was defined using paired t-tests as well as correlation and linear regression. Results: ECAP thresholds were significantly correlated with the perceptual dynamic range measures studied; however, correlations were not strong. Analysis of the individual data revealed considerable discrepancy between the contour of ECAP threshold versus electrode function and the behavioral loudness estimates used for programming. Conclusion: ECAP thresholds recorded from Advanced Bionics cochlear implant users always indicated levels where the programming stimulus was audible for the listener. However, the correlation between ECAP thresholds and M-levels (the primary metric used to program the speech processor of the Advanced Bionics CI), while statistically significant, was quite modest. If programming levels are to be determined on the basis of ECAP thresholds, care should be taken to ensure that stimulation is not uncomfortably loud, particularly on the basal electrodes in the array.

scholarly journals In-vitro characterization of a cochlear implant system for recording of evoked compound action potentials

2012 ◽  
Vol 11 (1) ◽  
pp. 22 ◽  
Author(s):  
Christian Neustetter ◽  
Matthias Zangerl ◽  
Philipp Spitzer ◽  
Clemens Zierhofer
Keyword(s):  
Cochlear Implant ◽  
Action Potentials ◽  
In Vitro Characterization ◽  
Compound Action Potentials ◽  
Implant System ◽  
Compound Action

scholarly journals Characterization of Cochlear, Vestibular and Cochlear-Vestibular Electrically Evoked Compound Action Potentials in Patients with a Vestibulo-Cochlear Implant

2017 ◽  
Vol 11 ◽  
Author(s):  
T. A. K. Nguyen ◽  
Samuel Cavuscens ◽  
Maurizio Ranieri ◽  
Konrad Schwarz ◽  
Nils Guinand ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Action Potentials ◽  
Compound Action Potentials ◽  
Compound Action

scholarly journals Effect of Depth of Total Intravenous General Anesthesia on Intraoperative Electrically Evoked Compound Action Potentials in Cochlear Implantation Surgery

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Ala”a Alhowary ◽  
Abdelwahab Aleshawi ◽  
Obada Alali ◽  
Manal Kassab ◽  
Diab Bani Hani ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Cochlear Implantation ◽  
Action Potentials ◽  
Compound Action Potential ◽  
Cochlear Implant Surgery ◽  
Compound Action Potentials ◽  
Evoked Compound Action Potential ◽  
Electrode Lead ◽  
Intravenous General Anesthesia ◽  
Compound Action

Purpose. This study aims to compare the effect of the depth of total intravenous anesthesia (TIVA) on intraoperative electrically evoked compound action potential (e-ECAP) thresholds in cochlear implant operations. Methods. Prospectively, a total of 39 patients aged between 1 and 48 years who were scheduled to undergo cochlear implantation surgeries were enrolled in this study. Every patient received both light and deep TIVA during the cochlear implant surgery. The e-ECAP thresholds were obtained during the light and deep TIVA. Results. After comparing the e-ECAP means for each electrode (lead) between the light and deep anesthesia, no significant differences were detected between the light and deep anesthesia. Conclusion. The depth of TIVA may have no significant influence on the e-ECAP thresholds as there was no statistical difference between the light and deep anesthesia.

Use of Electrically Evoked Compound Action Potentials for Cochlear Implant Fitting

2018 ◽  
Vol 39 (3) ◽  
pp. 401-411 ◽  
Author(s):  
Johan J. de Vos ◽  
Jan Dirk Biesheuvel ◽  
Jeroen J. Briaire ◽  
Pieter S. Boot ◽  
Margriet J. van Gendt ◽  
...  
Keyword(s):  
Cochlear Implant ◽  
Action Potentials ◽  
Compound Action Potentials ◽  
Compound Action

scholarly journals SpeedCAP: An Efficient Method for Estimating Neural Activation Patterns Using Electrically-Evoked Compound Action-Potentials in Cochlear Implant Users

2021 ◽  
Author(s):  
Charlotte Garcia ◽  
John M. Deeks ◽  
Tobias Goehring ◽  
Daniele Borsetto ◽  
Manohar Bance ◽  
...  
Keyword(s):  
Data Collection ◽  
Cochlear Implant ◽  
Action Potentials ◽  
Forward Masking ◽  
Patient Specific ◽  
Neural Activation ◽  
Current Spread ◽  
Wide Range ◽  
Compound Action Potentials ◽  
Compound Action

Objectives: Electrically-Evoked Compound Action-Potentials (ECAPs) can be recorded using the electrodes in a cochlear implant (CI) and represent the synchronous responses of the electrically-stimulated auditory-nerve. ECAPs can be obtained using a forward-masking method that measures the neural response to a probe and masker electrode separately and in combination. The Panoramic ECAP (PECAP) method measures ECAPs using multiple combinations of masker and probe electrodes and uses a nonlinear optimization algorithm to estimate current spread from each electrode and neural health along the cochlea. However, the measurement of ECAPs from multiple combinations of electrodes is too time-consuming for use in clinics. This study proposes and evaluates a fast version of the PECAP measurements, SpeedCAP, that minimises recording time by exploiting redundancies between multiple ECAP measures, and that can be applied to methods where multiple ECAPs are required. Design: In the first study, 11 users of Cochlear Limited CIs took part. ECAPs were recorded using the forward-masking artefact-cancellation technique at the most comfortable loudness level (MCL) for every combination of masker and probe electrodes for all active electrodes in the users’ MAPs, as per the standard PECAP recording paradigm. The same current levels and recording parameters were then used to collect ECAPs in the same users with the SpeedCAP method. The ECAP amplitudes were then compared between the two conditions, as were the corresponding estimates of neural health and current spread calculated using the PECAP method described by Garcia et al (2021). The second study measured SpeedCAP intra-operatively in 8 CI patients and with all maskers and probes presented at the same current level to assess feasibility. ECAPs for the subset of conditions where the masker and probe were presented on the same electrode were compared to those obtained using the slower approach leveraged by the standard clinical software. Results: Data collection time was reduced from 45 (PECAP) to 8 (SpeedCAP) minutes. There were no significant differences between normalized root mean squared error (RMSE) repeatability metrics for post-operative PECAP and SpeedCAP data, nor for the RMSEs calculated between PECAP and SpeedCAP data. When between-participant differences were removed, both the neural health (r = 0.73) and current spread (r = 0.65) estimates were significantly correlated (p < 0.0001, df = 218) between SpeedCAP and PECAP conditions across all electrodes. Valid ECAPs were obtained in all patients in the second study, demonstrating intra-operative feasibility of SpeedCAP. No significant differences in RMSEs were detectable between post- and intra-operative ECAP measurements. Conclusions: The improved efficiency of SpeedCAP provides time savings facilitating multi-electrode ECAP recordings in routine clinical practice. The SpeedCAP data collection is sufficiently quick to record intra-operatively, and adds no significant error to the ECAP amplitudes. Such measurements could thereafter be submitted to models such as PECAP to provide patient-specific patterns of neural activation to inform programming of clinical MAPs and/or identify causes of poor performance at the electrode-nerve interface of CI users. The speed and accuracy of these measurements also opens up a wide range of additional research questions to be addressed.

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