Details
| Original language | English |
|---|---|
| Article number | 20136 |
| Journal | Scientific reports |
| Volume | 15 |
| Issue number | 1 |
| Publication status | Published - 20 Jun 2025 |
Abstract
Cochlear implants are a well-established solution for restoring hearing in severe impairment and profound deafness. However, cochlear implants still have limitations, such as speech recognition in noisy environments caused by intra-cochlear current spread across different auditory spiral ganglion neurons as a consequence of, e.g., the large distance of the stimulation electrodes to the target cells in a highly conductive environment. Stimulation in cochlear implants is typically done with charge balanced biphasic rectangular current pulses in a monopolar arrangement. However, several studies have shown that a rectangular stimulation pulse is not optimal for stimulating spiral ganglion neurons. For example, stimulation with a ramped pulse, such as a sawtooth pulse, has been shown to be more energy-efficient and achieves a similar threshold profile in spiral ganglion neurons. In this study, a new but simple equivalent electrical circuit model is introduced that describes the complex impedance between two stimulation electrodes of a cochlear implant with high accuracy (mean relative error ≤ 8%). Based on this bipolar model, a monopolar equivalent electrical circuit model is developed to describe the stimulation between one stimulation electrode and a counter electrode located outside the cochlea. These two models now allow for analyzing the effect of stimulation pulse shape on power distribution in cochlear implant electrodes and surrounding tissue providing a tool for investigating stimulation efficiency with respect to energy losses in the cochlear implant electrode.
Keywords
- Cochlear implant, Electrical equivalent circuit, Electrode–electrolyte interface, Impedance spectroscopy, Numerical signal analysis
ASJC Scopus subject areas
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In: Scientific reports, Vol. 15, No. 1, 20136, 20.06.2025.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Electrical equivalent circuit for analyzing the effect of signal shape on power distribution in cochlear implant electrodes and surrounding tissue
AU - Sehlmeyer, Merle
AU - Makarenko, Mariia
AU - Schoerner, Nele
AU - Bhavsar, Mit B.
AU - Blank, Tatiana
AU - Maier, Hans Jürgen
AU - Kral, Andrej
AU - Maier, Hannes
AU - Zimmermann, Stefan
N1 - Publisher Copyright: © The Author(s) 2025.
PY - 2025/6/20
Y1 - 2025/6/20
N2 - Cochlear implants are a well-established solution for restoring hearing in severe impairment and profound deafness. However, cochlear implants still have limitations, such as speech recognition in noisy environments caused by intra-cochlear current spread across different auditory spiral ganglion neurons as a consequence of, e.g., the large distance of the stimulation electrodes to the target cells in a highly conductive environment. Stimulation in cochlear implants is typically done with charge balanced biphasic rectangular current pulses in a monopolar arrangement. However, several studies have shown that a rectangular stimulation pulse is not optimal for stimulating spiral ganglion neurons. For example, stimulation with a ramped pulse, such as a sawtooth pulse, has been shown to be more energy-efficient and achieves a similar threshold profile in spiral ganglion neurons. In this study, a new but simple equivalent electrical circuit model is introduced that describes the complex impedance between two stimulation electrodes of a cochlear implant with high accuracy (mean relative error ≤ 8%). Based on this bipolar model, a monopolar equivalent electrical circuit model is developed to describe the stimulation between one stimulation electrode and a counter electrode located outside the cochlea. These two models now allow for analyzing the effect of stimulation pulse shape on power distribution in cochlear implant electrodes and surrounding tissue providing a tool for investigating stimulation efficiency with respect to energy losses in the cochlear implant electrode.
AB - Cochlear implants are a well-established solution for restoring hearing in severe impairment and profound deafness. However, cochlear implants still have limitations, such as speech recognition in noisy environments caused by intra-cochlear current spread across different auditory spiral ganglion neurons as a consequence of, e.g., the large distance of the stimulation electrodes to the target cells in a highly conductive environment. Stimulation in cochlear implants is typically done with charge balanced biphasic rectangular current pulses in a monopolar arrangement. However, several studies have shown that a rectangular stimulation pulse is not optimal for stimulating spiral ganglion neurons. For example, stimulation with a ramped pulse, such as a sawtooth pulse, has been shown to be more energy-efficient and achieves a similar threshold profile in spiral ganglion neurons. In this study, a new but simple equivalent electrical circuit model is introduced that describes the complex impedance between two stimulation electrodes of a cochlear implant with high accuracy (mean relative error ≤ 8%). Based on this bipolar model, a monopolar equivalent electrical circuit model is developed to describe the stimulation between one stimulation electrode and a counter electrode located outside the cochlea. These two models now allow for analyzing the effect of stimulation pulse shape on power distribution in cochlear implant electrodes and surrounding tissue providing a tool for investigating stimulation efficiency with respect to energy losses in the cochlear implant electrode.
KW - Cochlear implant
KW - Electrical equivalent circuit
KW - Electrode–electrolyte interface
KW - Impedance spectroscopy
KW - Numerical signal analysis
UR - http://www.scopus.com/inward/record.url?scp=105008716675&partnerID=8YFLogxK
U2 - 10.1038/s41598-025-04840-5
DO - 10.1038/s41598-025-04840-5
M3 - Article
AN - SCOPUS:105008716675
VL - 15
JO - Scientific reports
JF - Scientific reports
SN - 2045-2322
IS - 1
M1 - 20136
ER -