Excitation patterns of simultaneous and sequential dual-electrode stimulation in cochlear implant recipients

Aniket A. Saoji, Leonid M. Litvak, Michelle L. Hughes

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Objective: Both simultaneous (SI) and sequential stimulation of intracochlear electrodes can be used to generate pitches that are intermediate to the physical electrodes (PEs). The goal of this study was to compare the spread of neural excitation for SI and sequential dual-electrode stimulation with the spread of neural excitation for the intermediate electrode using electrically evoked compound action potentials. Design: Seven Advanced Bionics cochlear implant users with either CII or HiRes 90k implant and HiFocus 1 or HiFocus 1j electrode array participated in this study. A masker-probe subtraction method was used to derive neural excitation patterns for SI nonadjacent dual-electrode stimulation, apical and basal-first sequential nonadjacent dual-electrode stimulation, and the intermediate PE. For apical-first sequential (SEa) stimulation, the masker pulse on the apical electrode immediately preceded the masker pulse on the basal electrode, and vice versa for basal-first sequential stimulation (SEb). The electrodes used for dual-electrode stimulation were separated by an intermediate PE, which represents a spatial distance of approximately 2 mm. Current levels necessary to achieve comfortable loudness were determined for each masker and probe stimulus. During the evoked compound action potential measurements, the masker was fixed in location, whereas the probe was varied across a subset of electrodes in the array. Neural responses were calculated by subtracting the response to the probe from the masked response. Results: Neural excitation patterns were normalized to their peak and analyzed in terms of their area and center of gravity. The area and center of gravity for SI nonadjacent dual-electrode stimulation were similar to those of the intermediate PE. In contrast, the area for the two modes of sequential nonadjacent dual-electrode (SEa and SEb) stimulation differed significantly from the intermediate PE. The center of gravity for SEa stimulation also differed significantly from the intermediate PE, whereas there was no significant difference in the center of gravity between SEb stimulation and the intermediate PE. Conclusions: Peripheral neural activation patterns suggest a similar spread of excitation for SI dual-electrode stimulation and the intermediate PE. The spread of excitation associated with sequential dual-electrode stimulation is generally different from the intermediate PE, and it varies depending on the order of the sequential pulses.

Original languageEnglish (US)
Pages (from-to)559-567
Number of pages9
JournalEar and hearing
Volume30
Issue number5
DOIs
StatePublished - Oct 1 2009

Fingerprint

Cochlear Implants
Electrodes
Physical Stimulation
Gravitation
Action Potentials
Bionics

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Speech and Hearing

Cite this

Excitation patterns of simultaneous and sequential dual-electrode stimulation in cochlear implant recipients. / Saoji, Aniket A.; Litvak, Leonid M.; Hughes, Michelle L.

In: Ear and hearing, Vol. 30, No. 5, 01.10.2009, p. 559-567.

Research output: Contribution to journalArticle

Saoji, Aniket A. ; Litvak, Leonid M. ; Hughes, Michelle L. / Excitation patterns of simultaneous and sequential dual-electrode stimulation in cochlear implant recipients. In: Ear and hearing. 2009 ; Vol. 30, No. 5. pp. 559-567.
@article{f8b18200405241789a3cc4bb7cee279b,
title = "Excitation patterns of simultaneous and sequential dual-electrode stimulation in cochlear implant recipients",
abstract = "Objective: Both simultaneous (SI) and sequential stimulation of intracochlear electrodes can be used to generate pitches that are intermediate to the physical electrodes (PEs). The goal of this study was to compare the spread of neural excitation for SI and sequential dual-electrode stimulation with the spread of neural excitation for the intermediate electrode using electrically evoked compound action potentials. Design: Seven Advanced Bionics cochlear implant users with either CII or HiRes 90k implant and HiFocus 1 or HiFocus 1j electrode array participated in this study. A masker-probe subtraction method was used to derive neural excitation patterns for SI nonadjacent dual-electrode stimulation, apical and basal-first sequential nonadjacent dual-electrode stimulation, and the intermediate PE. For apical-first sequential (SEa) stimulation, the masker pulse on the apical electrode immediately preceded the masker pulse on the basal electrode, and vice versa for basal-first sequential stimulation (SEb). The electrodes used for dual-electrode stimulation were separated by an intermediate PE, which represents a spatial distance of approximately 2 mm. Current levels necessary to achieve comfortable loudness were determined for each masker and probe stimulus. During the evoked compound action potential measurements, the masker was fixed in location, whereas the probe was varied across a subset of electrodes in the array. Neural responses were calculated by subtracting the response to the probe from the masked response. Results: Neural excitation patterns were normalized to their peak and analyzed in terms of their area and center of gravity. The area and center of gravity for SI nonadjacent dual-electrode stimulation were similar to those of the intermediate PE. In contrast, the area for the two modes of sequential nonadjacent dual-electrode (SEa and SEb) stimulation differed significantly from the intermediate PE. The center of gravity for SEa stimulation also differed significantly from the intermediate PE, whereas there was no significant difference in the center of gravity between SEb stimulation and the intermediate PE. Conclusions: Peripheral neural activation patterns suggest a similar spread of excitation for SI dual-electrode stimulation and the intermediate PE. The spread of excitation associated with sequential dual-electrode stimulation is generally different from the intermediate PE, and it varies depending on the order of the sequential pulses.",
author = "Saoji, {Aniket A.} and Litvak, {Leonid M.} and Hughes, {Michelle L.}",
year = "2009",
month = "10",
day = "1",
doi = "10.1097/AUD.0b013e3181ab2b6f",
language = "English (US)",
volume = "30",
pages = "559--567",
journal = "Ear and Hearing",
issn = "0196-0202",
publisher = "Lippincott Williams and Wilkins",
number = "5",

}

TY - JOUR

T1 - Excitation patterns of simultaneous and sequential dual-electrode stimulation in cochlear implant recipients

AU - Saoji, Aniket A.

AU - Litvak, Leonid M.

AU - Hughes, Michelle L.

PY - 2009/10/1

Y1 - 2009/10/1

N2 - Objective: Both simultaneous (SI) and sequential stimulation of intracochlear electrodes can be used to generate pitches that are intermediate to the physical electrodes (PEs). The goal of this study was to compare the spread of neural excitation for SI and sequential dual-electrode stimulation with the spread of neural excitation for the intermediate electrode using electrically evoked compound action potentials. Design: Seven Advanced Bionics cochlear implant users with either CII or HiRes 90k implant and HiFocus 1 or HiFocus 1j electrode array participated in this study. A masker-probe subtraction method was used to derive neural excitation patterns for SI nonadjacent dual-electrode stimulation, apical and basal-first sequential nonadjacent dual-electrode stimulation, and the intermediate PE. For apical-first sequential (SEa) stimulation, the masker pulse on the apical electrode immediately preceded the masker pulse on the basal electrode, and vice versa for basal-first sequential stimulation (SEb). The electrodes used for dual-electrode stimulation were separated by an intermediate PE, which represents a spatial distance of approximately 2 mm. Current levels necessary to achieve comfortable loudness were determined for each masker and probe stimulus. During the evoked compound action potential measurements, the masker was fixed in location, whereas the probe was varied across a subset of electrodes in the array. Neural responses were calculated by subtracting the response to the probe from the masked response. Results: Neural excitation patterns were normalized to their peak and analyzed in terms of their area and center of gravity. The area and center of gravity for SI nonadjacent dual-electrode stimulation were similar to those of the intermediate PE. In contrast, the area for the two modes of sequential nonadjacent dual-electrode (SEa and SEb) stimulation differed significantly from the intermediate PE. The center of gravity for SEa stimulation also differed significantly from the intermediate PE, whereas there was no significant difference in the center of gravity between SEb stimulation and the intermediate PE. Conclusions: Peripheral neural activation patterns suggest a similar spread of excitation for SI dual-electrode stimulation and the intermediate PE. The spread of excitation associated with sequential dual-electrode stimulation is generally different from the intermediate PE, and it varies depending on the order of the sequential pulses.

AB - Objective: Both simultaneous (SI) and sequential stimulation of intracochlear electrodes can be used to generate pitches that are intermediate to the physical electrodes (PEs). The goal of this study was to compare the spread of neural excitation for SI and sequential dual-electrode stimulation with the spread of neural excitation for the intermediate electrode using electrically evoked compound action potentials. Design: Seven Advanced Bionics cochlear implant users with either CII or HiRes 90k implant and HiFocus 1 or HiFocus 1j electrode array participated in this study. A masker-probe subtraction method was used to derive neural excitation patterns for SI nonadjacent dual-electrode stimulation, apical and basal-first sequential nonadjacent dual-electrode stimulation, and the intermediate PE. For apical-first sequential (SEa) stimulation, the masker pulse on the apical electrode immediately preceded the masker pulse on the basal electrode, and vice versa for basal-first sequential stimulation (SEb). The electrodes used for dual-electrode stimulation were separated by an intermediate PE, which represents a spatial distance of approximately 2 mm. Current levels necessary to achieve comfortable loudness were determined for each masker and probe stimulus. During the evoked compound action potential measurements, the masker was fixed in location, whereas the probe was varied across a subset of electrodes in the array. Neural responses were calculated by subtracting the response to the probe from the masked response. Results: Neural excitation patterns were normalized to their peak and analyzed in terms of their area and center of gravity. The area and center of gravity for SI nonadjacent dual-electrode stimulation were similar to those of the intermediate PE. In contrast, the area for the two modes of sequential nonadjacent dual-electrode (SEa and SEb) stimulation differed significantly from the intermediate PE. The center of gravity for SEa stimulation also differed significantly from the intermediate PE, whereas there was no significant difference in the center of gravity between SEb stimulation and the intermediate PE. Conclusions: Peripheral neural activation patterns suggest a similar spread of excitation for SI dual-electrode stimulation and the intermediate PE. The spread of excitation associated with sequential dual-electrode stimulation is generally different from the intermediate PE, and it varies depending on the order of the sequential pulses.

UR - http://www.scopus.com/inward/record.url?scp=70349127372&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349127372&partnerID=8YFLogxK

U2 - 10.1097/AUD.0b013e3181ab2b6f

DO - 10.1097/AUD.0b013e3181ab2b6f

M3 - Article

VL - 30

SP - 559

EP - 567

JO - Ear and Hearing

JF - Ear and Hearing

SN - 0196-0202

IS - 5

ER -