The Experts below are selected from a list of 930 Experts worldwide ranked by ideXlab platform

K D Wise - One of the best experts on this subject based on the ideXlab platform.

  • a 32 site 4 channel high density electrode array for a Cochlear Prosthesis
    IEEE Journal of Solid-state Circuits, 2006
    Co-Authors: P T Bhatti, K D Wise
    Abstract:

    This paper describes a 32-site 4-channel high-density intraCochlear electrode array. Combining MEMS-based processing technology with active circuitry, the thin-film device realizes a stimulating site density three times that of commercial systems, delivering 500 muA biphasic current levels with 8-bit resolution and less than 1% charge mismatch. The minimum pulsewidth is 4 mus, and the per-channel power dissipation is 2.5 mW from plusmn2.5 V. The active circuit chip has a footprint of 2.4mmtimes2.9 mm. Serving as the end-effector of a Cochlear Prosthesis, the active array also provides site-impedance measurement and position-sensing functions

  • a 32 site 4 channel high density electrode array for a Cochlear Prosthesis
    International Solid-State Circuits Conference, 2006
    Co-Authors: P T Bhatti, K D Wise
    Abstract:

    This paper describes a 32-site 4-channel high-density intraCochlear electrode array. Combining MEMS-based processing technology with active circuitry, the thin-film device realizes a stimulating site density three times that of commercial systems, delivering 500 μA biphasic current levels with 8-bit resolution and less than 1% charge mismatch. The minimum pulsewidth is 4 μs, and the per-channel power dissipation is 2.5 mW from ±2.5 V. The active circuit chip has a footprint of 2.4 mm x 2.9 mm. Serving as the end-effector of a Cochlear Prosthesis, the active array also provides site-impedance measurement and position-sensing functions.

P T Bhatti - One of the best experts on this subject based on the ideXlab platform.

  • a 32 site 4 channel high density electrode array for a Cochlear Prosthesis
    IEEE Journal of Solid-state Circuits, 2006
    Co-Authors: P T Bhatti, K D Wise
    Abstract:

    This paper describes a 32-site 4-channel high-density intraCochlear electrode array. Combining MEMS-based processing technology with active circuitry, the thin-film device realizes a stimulating site density three times that of commercial systems, delivering 500 muA biphasic current levels with 8-bit resolution and less than 1% charge mismatch. The minimum pulsewidth is 4 mus, and the per-channel power dissipation is 2.5 mW from plusmn2.5 V. The active circuit chip has a footprint of 2.4mmtimes2.9 mm. Serving as the end-effector of a Cochlear Prosthesis, the active array also provides site-impedance measurement and position-sensing functions

  • a 32 site 4 channel high density electrode array for a Cochlear Prosthesis
    International Solid-State Circuits Conference, 2006
    Co-Authors: P T Bhatti, K D Wise
    Abstract:

    This paper describes a 32-site 4-channel high-density intraCochlear electrode array. Combining MEMS-based processing technology with active circuitry, the thin-film device realizes a stimulating site density three times that of commercial systems, delivering 500 μA biphasic current levels with 8-bit resolution and less than 1% charge mismatch. The minimum pulsewidth is 4 μs, and the per-channel power dissipation is 2.5 mW from ±2.5 V. The active circuit chip has a footprint of 2.4 mm x 2.9 mm. Serving as the end-effector of a Cochlear Prosthesis, the active array also provides site-impedance measurement and position-sensing functions.

Jeffrey T Borenstein - One of the best experts on this subject based on the ideXlab platform.

  • the role of intraCochlear drug delivery devices in the management of inner ear disease
    Expert Opinion on Drug Delivery, 2015
    Co-Authors: Andrew M Ayoob, Jeffrey T Borenstein
    Abstract:

    INTRODUCTION: Diseases of the inner ear include those of the auditory and vestibular systems, and frequently result in disabling hearing loss or vertigo. Despite a rapidly expanding pipeline of potential Cochlear therapeutics, the inner ear remains a challenging organ for targeted drug delivery, and new technologies are required to deliver these therapies in a safe and efficacious manner. In addition to traditional approaches for direct inner ear drug delivery, novel microfluidics-based systems are under development, promising improved control over pharmacokinetics over longer periods of delivery, ultimately with application towards hair cell regeneration in humans. AREAS COVERED: Advances in the development of intraCochlear drug delivery systems are reviewed, including passive systems, active microfluidic technologies and Cochlear Prosthesis-mediated delivery. This article provides a description of novel delivery systems and their potential future clinical applications in treating inner ear disease. EXPERT OPINION: Recent progresses in microfluidics and miniaturization technologies are enabling the development of wearable and ultimately implantable drug delivery microsystems. Progress in this field is being spurred by the convergence of advances in molecular biology, microfluidic flow control systems and models for drug transport in the inner ear. These advances will herald a new generation of devices, with near-term applications in preclinical models, and ultimately with human clinical use for a range of diseases of the inner ear.

  • the role of intraCochlear drug delivery devices in the management of inner ear disease
    Expert Opinion on Drug Delivery, 2015
    Co-Authors: Andrew M Ayoob, Jeffrey T Borenstein
    Abstract:

    Introduction: Diseases of the inner ear include those of the auditory and vestibular systems, and frequently result in disabling hearing loss or vertigo. Despite a rapidly expanding pipeline of potential Cochlear therapeutics, the inner ear remains a challenging organ for targeted drug delivery, and new technologies are required to deliver these therapies in a safe and efficacious manner. In addition to traditional approaches for direct inner ear drug delivery, novel microfluidics-based systems are under development, promising improved control over pharmacokinetics over longer periods of delivery, ultimately with application towards hair cell regeneration in humans.Areas covered: Advances in the development of intraCochlear drug delivery systems are reviewed, including passive systems, active microfluidic technologies and Cochlear Prosthesis-mediated delivery. This article provides a description of novel delivery systems and their potential future clinical applications in treating inner ear disease.Expert...

Andrew M Ayoob - One of the best experts on this subject based on the ideXlab platform.

  • the role of intraCochlear drug delivery devices in the management of inner ear disease
    Expert Opinion on Drug Delivery, 2015
    Co-Authors: Andrew M Ayoob, Jeffrey T Borenstein
    Abstract:

    INTRODUCTION: Diseases of the inner ear include those of the auditory and vestibular systems, and frequently result in disabling hearing loss or vertigo. Despite a rapidly expanding pipeline of potential Cochlear therapeutics, the inner ear remains a challenging organ for targeted drug delivery, and new technologies are required to deliver these therapies in a safe and efficacious manner. In addition to traditional approaches for direct inner ear drug delivery, novel microfluidics-based systems are under development, promising improved control over pharmacokinetics over longer periods of delivery, ultimately with application towards hair cell regeneration in humans. AREAS COVERED: Advances in the development of intraCochlear drug delivery systems are reviewed, including passive systems, active microfluidic technologies and Cochlear Prosthesis-mediated delivery. This article provides a description of novel delivery systems and their potential future clinical applications in treating inner ear disease. EXPERT OPINION: Recent progresses in microfluidics and miniaturization technologies are enabling the development of wearable and ultimately implantable drug delivery microsystems. Progress in this field is being spurred by the convergence of advances in molecular biology, microfluidic flow control systems and models for drug transport in the inner ear. These advances will herald a new generation of devices, with near-term applications in preclinical models, and ultimately with human clinical use for a range of diseases of the inner ear.

  • the role of intraCochlear drug delivery devices in the management of inner ear disease
    Expert Opinion on Drug Delivery, 2015
    Co-Authors: Andrew M Ayoob, Jeffrey T Borenstein
    Abstract:

    Introduction: Diseases of the inner ear include those of the auditory and vestibular systems, and frequently result in disabling hearing loss or vertigo. Despite a rapidly expanding pipeline of potential Cochlear therapeutics, the inner ear remains a challenging organ for targeted drug delivery, and new technologies are required to deliver these therapies in a safe and efficacious manner. In addition to traditional approaches for direct inner ear drug delivery, novel microfluidics-based systems are under development, promising improved control over pharmacokinetics over longer periods of delivery, ultimately with application towards hair cell regeneration in humans.Areas covered: Advances in the development of intraCochlear drug delivery systems are reviewed, including passive systems, active microfluidic technologies and Cochlear Prosthesis-mediated delivery. This article provides a description of novel delivery systems and their potential future clinical applications in treating inner ear disease.Expert...

Clark, Graeme M. - One of the best experts on this subject based on the ideXlab platform.

  • Biomedical studies on temporal bones of the first multi-channel Cochlear implant patient at the University of Melbourne
    'Maney Publishing', 2014
    Co-Authors: Clark, Graeme M., Clark Jonathan, Cardamone Tina, Clarke Maria, Nielsen Prue, Jones Rob, Arhatari Benedicta, Birbilis Nick, Curtain Roger, Xu Jin
    Abstract:

    Objective : To analyse the temporal bones and implant of the first University of Melbourne’s (UOM) patient (MC-1) to receive the multi-channel Cochlear Prosthesis. Methods: The left cochlea was implanted with the prototype multi-channel Cochlear Prosthesis on 1 August 1978, and the Cochlear versions CI-22 and CI-24 on 22 June 1983 and 10 November 1998, respectively. MC-1 died in 2007. Results : Plain X-rays of the temporal bones showed that after the CI-22 had been explanted seven electrode bands remained in situ. Micro-CT scans also revealed a partially united fracture transecting the left implanted and right control cochleae. Histology indicated a total loss of the organ of Corti on both sides, and a tear of the left basilar membrane. In addition, there was a dense fibrous capsule with heterotopic bone surrounding one proximal band of the CI-22 array that restricted its removal. This pathology was associated with dark particulate material within macrophages, probably due to the release of platinum from the electrode bands. Scanning electron microscopy (SEM) showed possible corrosion of platinum and surface roughening. Three-dimensional reconstruction of the Cochlear histology demonstrated the position of the electrode tracts (C1-22 and CI-24) in relation to the spiral ganglion, which showed 85–90% loss of ganglion cells. Discussion and conclusions : This study confirms our first histopathological findings that our first free-fitting banded electrode array produced moderate trauma to the cochlea when inserted around the scala tympani of the basal turn. The difficulty in extraction was most likely due to one band being surrounded by an unusually large amount of fibrous tissue and bone, with an electrode band caught due to surface irregularities. Some surface corrosion and a small degree of platinum deposition in the tissue may also help explain the outcome for this long-term Cochlear implantation

  • What factors contribute to successful outcomes for children using Cochlear implants
    2000
    Co-Authors: Cowan, Robert C., Clark, Graeme M., Dowell, Richard C., Dettman, Shani J, Barker Elizabeth, Latus Katie, Hollow Rod, Blamey, Peter J.
    Abstract:

    Long term speech perception data has been collected for 100 children using the Nucleus multichannel Cochlear Prosthesis in Melbourne. Scores on a number of different assessments are available at approximately six month intervals following implantation for these children. The group represents an unselected sample of Cochlear implant users, as all children were included if they had sufficient developmental skills to perform formal speech perception tests. Information was also collected on each child regarding type of hearing loss, age of onset of profound hearing loss, duration of profound hearing loss, age at implantation, pre and post-implant communication mode, developmental delay, speech processing strategy and length of experience with implant use.9-13 Jul

  • The development of speech perception in children using Cochlear implants: effects of etiologic factors and delayed milestones
    2000
    Co-Authors: Pyman Brian, Clark, Graeme M., Blamey, Peter J., Lacy Peter, Dowell Richard
    Abstract:

    Publisher's version is restricted access in accordance with the publisher's policy.Hypothesis: Speech perception outcomes for Cochlear implantation of children vary over a wide range, and it is hypothesized that central pathologic states associated with certain causes of hearing impairment account for a substantial part of the variance. Study Design: A retrospective analysis was carried out to ascertain the relationships between speech perception, etiologic factors, and central pathologic states as indicated by preoperative delayed motor milestones and/or cognitive delays. Setting: Data were obtained from the pre-and postoperative records of patients attending a hospital Cochlear implant clinic. Patients: Results for 75 consecutive patients up to age 5 years who underwent implantation were included in the study. Intervention: Patients received a 22-electrode Cochlear Prosthesis and were seen by the clinic for regular tune-up and assessments. Home-and school-based habilitation was recommended by the clinic. Main Outcome Measures: Speech perception measures were classified on a five-point scale to allow for different evaluation procedures at different ages and developmental stages. Results: The incidence of motor and cognitive delays were fairly evenly spread across etiologic factors, except for cytomegalovirus, which had a much higher than average incidence. Children with motor and/or cognitive delays were significantly slower than other children in the development of speech perception skills after implantation. Etiologic factors did not have a statistically significant effect on speech perception outcome. Conclusions: It is likely that central pathologic states account for a substantial part of the variance among children using Cochlear implants. Specific indicators of central pathologic states should be used to assess a child's prognosis in preference to less specific information based on etiologic factors alone

  • Psychophysics of a peri-modiolar electrode array
    1999
    Co-Authors: Cohen, Lawrence T., Saunders E., Clark, Graeme M.
    Abstract:

    Psychophysical findings in three adult patients implanted with a CI22 Cochlear Prosthesis (Cochlear Limited) fitted with a developmental peri-modiolar electrode array have been reported. This array was moulded with a curvature approximating that of the inner wall of scala tympani but, after straightening and insertion into the cochlea, it adopted a position on average approximately half way between the inner and outer walls. However, the considerable variations in electrode trajectories across subjects allowed an analysis which could separate the effects due to longitudinal distance into the cochlea and lateral distance from the modiolus. Radiographic analysis enabled the positions of the individual electrodes to be measured, both longitudinally and laterally. This paper presents additional results and an in-depth analysis of the data, supported by psychophysical findings in subjects with straight arrays. It also introduces a model which describes the effect of distance from the modiolus on the loudness growth function.29 August - 3 Septembe

  • Speech cues for Cochlear implantees: spectral discrimination
    Monduzzi Editore, 1997
    Co-Authors: Henry, Belinda A., Mckay, Colette M., Mcdermott, Hugh J., Clark, Graeme M.
    Abstract:

    This is a publisher’s version of a paper from XVI World Congress of Otohinolaryngology Head and Neck Surgery 1997, published by Monduzzi Editore. This version is reproduced with the permission of the publisher.The relationship between the ability of Cochlear implantees to perceive speech and their ability to discriminate between stimulation on adjacent electrodes was investigated. Speech perception ability was assessed with monosyllabic words in 8 users Nucleus Cochlear Prosthesis. The ability of these subjects to discriminate between stimulation on adjacent electrodes, in of random loudness differences between electrodes was determined. Results were averaged in the apical, mid and basal regions of the cochlea. Regression analysis showed that speech perception ability and electrode discrimination ability were correlated in the apical to mid region of the cochlea. but the two factors were not correlated in the basal region. Therefore, these results suggest that implantees require the ability to discriminate between stimulation on adjacent electrodes in the apical to mid region of the cochlea in order to achieve high speech perception scores.2-7 Marc