Publications by authors named "Stephen O'Leary"

Background: The aim of this study was to relate response patterns of electrocochleography (ECochG) recordings during cochlear implantation to pre- and postoperative hearing.

Methods: Thirty subjects with either flat (FA, n = 9) or sloping (SA, n = 21) audiograms before cochlear implantation were prospectively included. Real-time ECochG recordings were conducted via the cochlear implant.

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Objectives: Real-time monitoring of cochlear function to predict the loss of residual hearing after cochlear implantation is now possible. Current approaches monitor the cochlear microphonic (CM) during implantation from the electrode at the tip of the implant. A drop in CM response of >30% is associated with poorer hearing outcomes.

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As important primary producers and key components of biogeochemical processes, phytoplankton communities are highly diverse and continually adapt to changes in the environment, impacting the entire marine ecosystem. Consequently, it remains important to isolate, culture and properly describe new phytoplankton strains to provide relevant model organisms for laboratory research and accurate reference sequences for identification. Here, 73 phytoplankton strains from the eastern Canadian waters were isolated and genetically characterized using a long rRNA fragment (~4000 bp) covering the 18S, ITS and 28S rRNA regions generated with long-read sequencing technology.

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Purpose: The position and orientation of the head is maintained to be relatively similar during the CT / MR imaging process. However, the position / orientation dissimilarities present in the resulting images between patients, or between different scans of the same patient, do not allow for direct comparison of the images themselves or features / metrics extracted from them. This paper introduces a method of defining a coordinate system which is consistent between patients and modalities (CT and MR) for images of the temporal bone, using easily identifiable landmarks within the semicircular canals.

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Purpose: In cochlear implantation (CI) surgery, there are a wide variety of intraoperative tests available. However, no clear guide exists on which tests must be performed as the minimum intraoperative testing battery. Toward this end, we studied the usage patterns, recommendations, and attitudes of practitioners toward intraoperative testing.

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, isolated from a pond adjacent to a cement plant, was cultured using flue gas collected directly from kiln emissions using 20 L and 25000 L photobioreactors. Lipids, proteins, and polysaccharides were analyzed to understand their overall composition for potential applications. The lipid content ranged from 17.

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Objectives: A wide variety of intraoperative tests are available in cochlear implantation. However, no consensus exists on which tests constitute the minimum necessary battery. We assembled an international panel of clinical experts to develop, refine, and vote upon a set of core consensus statements.

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Objectives: Electrocochleography (ECochG) appears to offer the most accurate prediction of post-cochlear implant hearing outcomes. This may be related to its capacity to interrogate the health of underlying cochlear tissue. The four major components of ECochG (cochlear microphonic [CM], summating potential [SP], compound action potential [CAP], and auditory nerve neurophonic [ANN]) are generated by different cochlear tissue components.

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Objectives: To determine the benefits of cochlear implantation in hearing loss children with multiple disabilities (MD) in terms of auditory outcomes, speech performance, and their quality of life.

Methods: This was a cross sectional study from January 2019 to December 2020 in which thirty-one children with hearing loss and multiple disabilities were evaluated. Their improvement in auditory and speech performances were assessed using Categories of Auditory Performance version II (CAP-II) and the Speech Intelligibility Rating (SIR) scales.

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Introduction: Preservation of residual hearing after cochlear implantation allows for electroacoustic stimulation, which leads to better music appreciation, noise localization, and speech comprehension in noisy environments. Real-time intraoperative electrocochleography (rt-ECochG) monitoring has shown promise in improving residual hearing rates. Four-point impedance (4PI) is being explored as a potential biomarker in cochlear implantation that has been associated with fibrotic tissue response, hearing loss, and dizziness.

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Background: The shape and position of cochlear implant electrodes could potentially influence speech perception, as this determines the proximity of implant electrodes to the spiral ganglion. However, the literature to date reveals no consistent association between speech perception and either the proximity of electrode to the medial cochlear wall or the depth of insertion. These relationships were explored in a group of implant recipients receiving the same precurved electrode.

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Hypothesis: Gross electrode movements detected with intraoperative, real-time X-ray fluoroscopy will correlate with fluctuations in cochlear output, as measured with intraoperative electrocochleography (ECochG).

Background: Indications for cochlear implantation (CI) are expanding to include patients with residual hearing; however, implant recipients often lose residual hearing after CI. The objective of this study was to identify probable traumatic events during implantation by combining electrophysiological monitoring of cochlear function with simultaneous X-ray monitoring.

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Biosensing technologies are emerging as an important consideration when designing implantable medical devices. For cochlear implants, biosensors may help preserve the natural hearing a patient has prior to implantation by detecting blood in the cochlea during insertion. If blood enters the cochlea, it creates a hostile environment leading to further hearing loss and reduced device function.

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Production of microalgae is a potential technology for capturing and recycling carbon dioxide from cement kiln emissions. In this study, a process of selecting a suitable strain that would effectively utilize carbon dioxide and generate biomass was investigated. A down-selection screening method was applied to 28 strains isolated from the area surrounding a commercial cement plant.

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Introduction: Intraoperative trauma leading to bleeding during cochlear implantation negatively impacts residual hearing of cochlear implant recipients. There are no clinical protocols for the removal of blood during implantation, to reduce the consequential effects such as inflammation and fibrosis which adversely affect cochlear health and residual hearing. This preclinical study investigated the implementation of an intra-cochlear flushing protocol for the removal of blood.

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Background: Systemically administered steroids are widely utilised for hearing preservation therapies. More recently, steroids have been administered to achieve hearing protection after cochlear implant surgery. Currently there is a lack of understanding as to which administration route offers most therapeutic efficacy, local or systemic administration.

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Introduction: Postimplantation dizziness is common, affecting approximately 50% of patients. Theories for dizziness include utricular inflammation, endolymphatic hydrops, and loss of perilymph. Four-point impedance (4PI) is a novel impedance measurement in cochlear implantation that shows potential to predict hearing loss, inflammation, and fibrotic tissue response.

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Objectives: The underlying state of cochlear and neural tissue function is known to affect postoperative speech perception following cochlear implantation. The ability to assess these tissues in patients can be performed using intracochlear electrocochleography (IC ECochG). One component of ECochG is the summating potential (SP) that appears to be generated by multiple cochlear tissues.

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Background: Surgical rehearsal - patient-specific preoperative surgical practice - can be provided by virtual reality simulation. This study investigated the effect of surgical rehearsal on cortical mastoidectomy performance and procedure duration.

Methods: University students (n=40) were randomized evenly into a rehearsal and control group.

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Objectives: Different patterns of electrocochleographic responses along the electrode array after insertion of the cochlear implant electrode array have been described. However, the implications of these patterns remain unclear. Therefore, the aim of the study was to correlate different peri- and postoperative electrocochleographic patterns with four-point impedance measurements and preservation of residual hearing.

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The level of hearing restoration in patients with severe to profound sensorineural hearing loss by means of cochlear implants (CIs) has drastically risen since the introduction of these neuroprosthetics. The proposed CI integrated with polymer optical fiber Bragg gratings (POFBGs) enables real-time evaluation of insertion forces and trajectory determination during implantation irrespective of the speed of insertion, as well as provides high signal quality, low stiffness levels, minimum induced stress even under forces of high magnitudes and exhibits significant reduction of the risk of fiber breakage inside the constricted cochlear geometry. As such, the proposed device opens new avenues towards atraumatic cochlear implantations and provides a direct route for the next generation of CIs with intraoperative insertion force assessment and path planning capacity crucial for surgical navigation.

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Objective: Monitor four-point impedance in cochlear implant recipients over time and determine if implant type, surgical approach, and electrode positioning affected impedance measurements.

Study Design: Prospective observational.

Setting: Hospital.

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The objective of this systematic review is to compare the diagnostic value of endolymphatic hydrops (EH) magnetic resonance imaging (MRI) with audiovestibular function tests, including electro cochleography (ECochG), cervical vestibular evoked myogenic potential (cVEMP) and caloric tests for the diagnosis of definite Meniere's disease (DMD). An electronic search was performed in the PubMed, Embase and Cochrane databases in August 2022. Original studies which reported the efficacy of gadolinium MRI for diagnosis of DMD were compared with ECochG, cVEMP and caloric tests from 2007 to 2022 published in English.

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