Cargando…

Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread

Cochlear implants (CIs) have tremendously helped people with severe to profound hearing loss to gain access to sound and oral–verbal communication. However, the electrical stimulus in the cochlea spreads easily and widely, since the perilymph and endolymph (i.e., intracochlear fluids) are essentiall...

Descripción completa

Detalles Bibliográficos
Autores principales: Jiang, C., de Rijk, S. R., Malliaras, G. G., Bance, M. L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470452/
https://www.ncbi.nlm.nih.gov/pubmed/32929397
http://dx.doi.org/10.1063/5.0012514
_version_ 1783578592064569344
author Jiang, C.
de Rijk, S. R.
Malliaras, G. G.
Bance, M. L.
author_facet Jiang, C.
de Rijk, S. R.
Malliaras, G. G.
Bance, M. L.
author_sort Jiang, C.
collection PubMed
description Cochlear implants (CIs) have tremendously helped people with severe to profound hearing loss to gain access to sound and oral–verbal communication. However, the electrical stimulus in the cochlea spreads easily and widely, since the perilymph and endolymph (i.e., intracochlear fluids) are essentially electrolytes, leading to an inability to focus stimulation to discrete portions of the auditory nerve, which blurs the neural signal. Here, we characterize the complex transimpedances of human cadaveric cochleas to investigate how electrical stimulus spread is distributed from 10 Hz to 100 kHz. By using electrochemical impedance spectroscopy (EIS), both the resistive and capacitive elements of human cochleas are measured and modeled with an electrical circuit model, identifying spread-induced and spread-independent impedance components. Based on this electrical circuit model, we implement a Laplace transform to simulate the theoretical shapes of the spread signals. The model is validated by experimentally applying the simulated stimulus as a real stimulus to the cochlea and measuring the shapes of the spread signals, with relative errors of <0.6% from the model. Based on this model, we show the relationship between stimulus pulse duration and electrical stimulus spread. This EIS technique to characterize the transimpedances of human cochleas provides a new way to predict the spread signal under an arbitrary electrical stimulus, thus providing preliminary guidance to the design of CI stimuli for different CI users and coding strategies.
format Online
Article
Text
id pubmed-7470452
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher AIP Publishing LLC
record_format MEDLINE/PubMed
spelling pubmed-74704522021-03-11 Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread Jiang, C. de Rijk, S. R. Malliaras, G. G. Bance, M. L. APL Mater Articles Cochlear implants (CIs) have tremendously helped people with severe to profound hearing loss to gain access to sound and oral–verbal communication. However, the electrical stimulus in the cochlea spreads easily and widely, since the perilymph and endolymph (i.e., intracochlear fluids) are essentially electrolytes, leading to an inability to focus stimulation to discrete portions of the auditory nerve, which blurs the neural signal. Here, we characterize the complex transimpedances of human cadaveric cochleas to investigate how electrical stimulus spread is distributed from 10 Hz to 100 kHz. By using electrochemical impedance spectroscopy (EIS), both the resistive and capacitive elements of human cochleas are measured and modeled with an electrical circuit model, identifying spread-induced and spread-independent impedance components. Based on this electrical circuit model, we implement a Laplace transform to simulate the theoretical shapes of the spread signals. The model is validated by experimentally applying the simulated stimulus as a real stimulus to the cochlea and measuring the shapes of the spread signals, with relative errors of <0.6% from the model. Based on this model, we show the relationship between stimulus pulse duration and electrical stimulus spread. This EIS technique to characterize the transimpedances of human cochleas provides a new way to predict the spread signal under an arbitrary electrical stimulus, thus providing preliminary guidance to the design of CI stimuli for different CI users and coding strategies. AIP Publishing LLC 2020-09-01 /pmc/articles/PMC7470452/ /pubmed/32929397 http://dx.doi.org/10.1063/5.0012514 Text en © 2020 Author(s). 2166-532X/2020/8(9)/091102/8/$0.00 All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Articles
Jiang, C.
de Rijk, S. R.
Malliaras, G. G.
Bance, M. L.
Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title_full Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title_fullStr Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title_full_unstemmed Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title_short Electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
title_sort electrochemical impedance spectroscopy of human cochleas for modeling cochlear implant electrical stimulus spread
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7470452/
https://www.ncbi.nlm.nih.gov/pubmed/32929397
http://dx.doi.org/10.1063/5.0012514
work_keys_str_mv AT jiangc electrochemicalimpedancespectroscopyofhumancochleasformodelingcochlearimplantelectricalstimulusspread
AT derijksr electrochemicalimpedancespectroscopyofhumancochleasformodelingcochlearimplantelectricalstimulusspread
AT malliarasgg electrochemicalimpedancespectroscopyofhumancochleasformodelingcochlearimplantelectricalstimulusspread
AT banceml electrochemicalimpedancespectroscopyofhumancochleasformodelingcochlearimplantelectricalstimulusspread