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dc.contributor.advisorDonald K. Eddington.en_US
dc.contributor.authorCrema, Matthew Ven_US
dc.contributor.otherHarvard--MIT Program in Health Sciences and Technology.en_US
dc.date.accessioned2017-03-10T15:05:47Z
dc.date.available2017-03-10T15:05:47Z
dc.date.copyright2016en_US
dc.date.issued2016en_US
dc.identifier.urihttp://hdl.handle.net/1721.1/107333
dc.descriptionThesis: S.M., Harvard-MIT Program in Health Sciences and Technology, 2016.en_US
dc.descriptionCataloged from PDF version of thesis.en_US
dc.descriptionIncludes bibliographical references (pages 179-189).en_US
dc.description.abstractCochlear implants are devices that aim to restore a measure of hearing to the deaf by converting acoustic signals to electric stimuli delivered to electrodes implanted in the inner ear. Theoretically, the phased array stimulation strategy described by van den Honert and Kelsall (2007) provides much better control over the neural excitation patters elicited by electric stimulation by taking advantage of potential field superposition in the implanted cochlea, to construct stimuli for optimally selective excitation of auditory nerve fibers. If the phased array strategy can be implemented using a commonly-implanted commercial cochlear implant system, the strategy could be effectively evaluated in a relatively large sample of patients to determine whether it provides better speech reception than currently available systems. This thesis investigates whether the phased array strategy can be implemented using the Advanced Bionics Clarion CH or HiRes90k cochlear implant. It is shown that for realistic cochlear implant electrode impedance magnitudes, the Advanced Bionics cochlear implant current sources will deliver monopolar current suitable for the necessary measurement of transimpedance with less than 7% error. Transimpedance matrix estimates were obtained in 11 ears in 10 cochlear implant subjects. Measurements reveal that in some test subjects, low impedance current paths exist between implanted electrodes that may cause current leakage through unintended electrodes. Researchers and clinicians should consider using this transimpedance matrix estimation technique to screen for patients or research subjects who could benefit from compensatory changes to their speech processors. The results of this thesis suggest that the phased array strategy can be implemented successfully when the limitations of the internal power supply documented in this document are taken into account. It is recommended that the transimpedance matrix in a given test subject be measured on the day of any psychophysical testing because of the potential impact of variability in transimpedance over time.en_US
dc.description.statementofresponsibilityby Matthew V. Crema.en_US
dc.format.extent189 pagesen_US
dc.language.isoengen_US
dc.publisherMassachusetts Institute of Technologyen_US
dc.rightsMIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission.en_US
dc.rights.urihttp://dspace.mit.edu/handle/1721.1/7582en_US
dc.subjectHarvard--MIT Program in Health Sciences and Technology.en_US
dc.titleCan the phased array stimulation strategy be implemented using the advanced bionics cochlear implant?en_US
dc.typeThesisen_US
dc.description.degreeS.M.en_US
dc.contributor.departmentHarvard--MIT Program in Health Sciences and Technology.en_US
dc.identifier.oclc972903362en_US


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