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The Intra-Cochlear Impedance-Matrix (IIM) test for the Nucleus (R) cochlear implant

Hey, Matthias; Boehnke, Britta; Dillier, Norbert; Hoppe, Ulrich; Eskilsson, Gunnar; Löwgren, Karolina LU ; Cullington, Helen; Mauch, Herbert and Mueller-Deile, Joachim (2015) In Biomedizinische Technik / Biomedical Engineering 60(2). p.123-133
Abstract
Objective: To describe the principles and operation of a new telemetry-based function test for the Nucleus (R) cochlear implant, known as the CS19 Intra-Cochlear Impedance Matrix (IIM) and to present results from a multicentre clinical study to establish reproducibility (test-retest reliability) and normative ranges. Method: The IIM test measures bipolar impedances between all electrode pairs and employs a normalization procedure based on common ground impedances in order to identify abnormal current paths among electrodes. Six European clinics collected IIM data from a total of 192 devices. Results: Reproducibility was high between initial and repeat measurements. The normative analysis demonstrated narrow ranges among devices after... (More)
Objective: To describe the principles and operation of a new telemetry-based function test for the Nucleus (R) cochlear implant, known as the CS19 Intra-Cochlear Impedance Matrix (IIM) and to present results from a multicentre clinical study to establish reproducibility (test-retest reliability) and normative ranges. Method: The IIM test measures bipolar impedances between all electrode pairs and employs a normalization procedure based on common ground impedances in order to identify abnormal current paths among electrodes. Six European clinics collected IIM data from a total of 192 devices. Results: Reproducibility was high between initial and repeat measurements. The normative analysis demonstrated narrow ranges among devices after normalization of impedance data. The IIM is able to identify abnormal current paths that are not evident from standard impedance telemetry and may otherwise only be found utilising average electrode voltage measurements (AEV). Conclusions: The IIM test was found to be straightforward to perform clinically and demonstrated reproducible data with narrow ranges in normally-functioning devices. Because this test uses a very low stimulation level the IIM test is well suited for children or multiply handicapped CI users who cannot reliably report on their auditory percepts. The new algorithms show potential to improve implant integrity testing capabilities if implemented in future clinical software. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
bipolar, cochlear implant electrodes, common ground, impedance, short, circuit, telemetry
in
Biomedizinische Technik / Biomedical Engineering
volume
60
issue
2
pages
123 - 133
publisher
De Gruyter
external identifiers
  • wos:000352221600004
  • scopus:84926616832
ISSN
1862-278X
DOI
10.1515/bmt-2014-0058
language
English
LU publication?
yes
id
4eb3b53f-1b63-4de6-bd49-3b095c15d4ed (old id 5402874)
date added to LUP
2015-06-01 09:22:48
date last changed
2017-01-01 03:59:00
@article{4eb3b53f-1b63-4de6-bd49-3b095c15d4ed,
  abstract     = {Objective: To describe the principles and operation of a new telemetry-based function test for the Nucleus (R) cochlear implant, known as the CS19 Intra-Cochlear Impedance Matrix (IIM) and to present results from a multicentre clinical study to establish reproducibility (test-retest reliability) and normative ranges. Method: The IIM test measures bipolar impedances between all electrode pairs and employs a normalization procedure based on common ground impedances in order to identify abnormal current paths among electrodes. Six European clinics collected IIM data from a total of 192 devices. Results: Reproducibility was high between initial and repeat measurements. The normative analysis demonstrated narrow ranges among devices after normalization of impedance data. The IIM is able to identify abnormal current paths that are not evident from standard impedance telemetry and may otherwise only be found utilising average electrode voltage measurements (AEV). Conclusions: The IIM test was found to be straightforward to perform clinically and demonstrated reproducible data with narrow ranges in normally-functioning devices. Because this test uses a very low stimulation level the IIM test is well suited for children or multiply handicapped CI users who cannot reliably report on their auditory percepts. The new algorithms show potential to improve implant integrity testing capabilities if implemented in future clinical software.},
  author       = {Hey, Matthias and Boehnke, Britta and Dillier, Norbert and Hoppe, Ulrich and Eskilsson, Gunnar and Löwgren, Karolina and Cullington, Helen and Mauch, Herbert and Mueller-Deile, Joachim},
  issn         = {1862-278X},
  keyword      = {bipolar,cochlear implant electrodes,common ground,impedance,short,circuit,telemetry},
  language     = {eng},
  number       = {2},
  pages        = {123--133},
  publisher    = {De Gruyter},
  series       = {Biomedizinische Technik / Biomedical Engineering},
  title        = {The Intra-Cochlear Impedance-Matrix (IIM) test for the Nucleus (R) cochlear implant},
  url          = {http://dx.doi.org/10.1515/bmt-2014-0058},
  volume       = {60},
  year         = {2015},
}