Aaran Thomas Lewis

Aaran Thomas Lewis


Research Focus & Metrics

Academic Career Length

14Years (2013-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 July 2016 in Journal of Raman Spectroscopy
Verified
Journal Article
Open access
PDF file
ALAaran Thomas Lewis
Aaran Thomas Lewis
RGRiana Gaifulina
Riana Gaifulina
MIMartin Isabelle
Martin Isabelle
JDJennifer Dorney
Jennifer Dorney
MWMae L. Woods
Mae L. Woods
GTGeraint M. Thomas
Geraint M. Thomas
Raman spectroscopy (RS) is a powerful technique that permits the non‐destructive chemical analysis of cells and tissues without the need for expensive and complex sample preparation. To date, samples have been routinely mounted onto calcium fluoride (CaF2) as this material possesses the desired mechanical and optical properties for analysis, but CaF2 is both expensive and brittle and this prevents the technique from being routinely adopted. Furthermore, Raman scattering is a weak phenomenon and CaF2 provides no means of increasing signal. For RS to be widely adopted, particularly in the clinical field, it is crucial that spectroscopists identify an alternative, low‐cost substrate capable of providing high spectral signal to noise ratios with good spatial resolution. Results show that these desired properties are attainable when using mirrored stainless steel as a Raman substrate. When compared with CaF2, data show that stainless steel has a low background signal and provides an average signal increase of 1.43 times during tissue analysis and 1.64 times when analyzing cells. This result is attributed to a double‐pass of the laser beam through the sample where the photons from the source laser and the forward scattered Raman signal are backreflected and retroreflected from the mirrored steel surface and focused towards collection optics. The spatial resolution on stainless steel is at least comparable to that on CaF2 and it is not compromised by the reflection of the laser. Steel is a fraction of the cost of CaF2 and the reflection and focusing of photons improve signal to noise ratios permitting more rapid mapping. The low cost of steel coupled with its Raman signal increasing properties and robust durability indicates that steel is an ideal substrate for biological and clinical RS as it possesses key advantages over routinely used CaF2. © 2016 The Authors. Journal of Raman Spectroscopy Published by John Wiley & Sons Ltd.

1 November 2013 in Vibrational Spectroscopy
Verified
Journal Article
Closed access
SLS.P. Lewis
S.P. Lewis
ALAaran Thomas Lewis
Aaran Thomas Lewis
PLP.D. Lewis
P.D. Lewis

25 July 2022 in Otology & Neurotology
Verified
Journal Article
Open access
RBRobert Briggs
Robert Briggs
CBCatherine S. Birman
Catherine S. Birman
NBNicholas Baulderstone
Nicholas Baulderstone
ALAaran Thomas Lewis
Aaran Thomas Lewis
INIris H.Y. Ng
Iris H.Y. Ng
RCRobert Samuel Charles Cowan
Robert Samuel Charles Cowan
Objective: To investigate the clinical performance, safety, and patient-reported outcomes of an active osseointegrated steady-state implant system that uses piezoelectric technology. Study Design: A prospective, multicenter, open-label, single-arm, within-subject clinical investigation. Setting: Three tertiary referral clinical centers located in Melbourne, Sydney, and Hong Kong. Patients: Twenty-nine adult subjects, 24 with mixed hearing loss or conductive hearing loss and 5 with single-sided sensorineural deafness. Intervention: Implantation with the Cochlear Osia 2 System. Main Outcome Measures: Audiological threshold evaluation and speech recognition in quiet and in noise. Patient satisfaction and safety. Results: At 6-month follow-up after surgery, a mean improvement in pure-tone average of 26.0 dB hearing level and a mean improvement of 8.8 dB signal-to-noise ratio in speech reception threshold in noise was achieved with the investigational device as compared with the unaided situation. Usability of the investigational device was rated 71.4/100 mm for sound processor retention and 81.4/100 mm for overall comfort using a visual analog scale. Conclusion: These outcomes confirm the clinical safety, performance, and benefit of an innovative active transcutaneous bone conduction implant using a piezoelectric transducer design in subjects with conductive hearing loss, mixed hearing loss, or single-sided sensorineural deafness.

12 May 2021 in Laryngoscope Investigative Otolaryngology
Verified
Journal Article
Open access
PDF file
ALAaran Thomas Lewis
Aaran Thomas Lewis
BVBarbara Vanaelst
Barbara Vanaelst
HHHåkan Hua
Håkan Hua
BCByung Yoon Choi
Byung Yoon Choi
RJRafael Jaramillo
Rafael Jaramillo
MHMyrthe K. S. Hol
Myrthe K. S. Hol
Objective: To assess the effectiveness of tympanoplasty in treating chronic otitis media‐related hearing loss, published literature was systematically reviewed to determine the clinical success rate of tympanoplasty at restoring hearing in chronic otitis media patients at a minimum follow‐up period of 12‐months.Data Sources: PubMed, Embase and the Cochrane Library.Methods: Two independent reviewers performed literature searches. Publications reporting long‐term (≥12‐month) hearing outcomes and complications data on adult and pediatric patients with chronic otitis media were included and assessed for risk of bias and strength of evidence. To assess how tympanoplasty influences long‐term hearing outcomes, data on pure tone audiometry (air‐bone gap) and complications were extracted and synthesized.Results: Thirty‐nine studies met the inclusion criteria. Data from 3162 patients indicated that 14.0% of patients encountered postoperative complications. In adult patients, mean weighted air‐bone gap data show closure from 26.5 dB hearing level (HL) (preoperatively) to 16.1 dB HL (postoperatively). In studies that presented combined adult and pediatric data, the mean preoperative air‐bone gap of 26.7 dB HL was closed to 15.4 dB HL. In 1370 patients with synthesizable data, 70.7% of patients had a postoperative air‐bone gap ˂ 20 dB HL at long‐term follow‐up. Finally, subgroup analysis identified that mean improvement in ABG closure for patients with and without cholesteatoma was 10.0 dB HL and 12.4 dB HL, respectively.Conclusion: In patients with chronic otitis media, tympanoplasty successfully closed the air‐bone gap to within 20 dB HL in 7/10 cases and had an overall complication rate of 14.0%.Level of Evidence: 2a.

8 August 2023 in European Archives of Oto-Rhino-Laryngology
Verified
Journal Article
Open access
PDF file
RCRobert Cowan
Robert Cowan
ALAaran Thomas Lewis
Aaran Thomas Lewis
CHCarina Hallberg
Carina Hallberg
MTMichael C. F. Tong
Michael C. F. Tong
CBCatherine S. Birman
Catherine S. Birman
RBRobert Briggs
Robert Briggs
Purpose: To investigate 2-year post-operative hearing performance, safety, and patient-reported outcomes of hearing-impaired adults treated with the Osia® 2 System, an active osseointegrated bone-conduction hearing implant that uses piezoelectric technology. Methods: A prospective, multicenter, open-label, single-arm, within-subject clinical study conducted at three tertiary referral clinical centers located in Melbourne, Sydney and Hong Kong. Twenty adult recipients of the Osia 2 System were enrolled and followed up between 12 and 24 months post-implantation: 17 with mixed or conductive hearing loss and 3 with single-sided sensorineural deafness. Safety data, audiological thresholds, speech recognition thresholds in noise, and patient-reported outcomes were collected and evaluated. In addition, pre-and 6-month post-implantation data were collected retrospectively for this recipient cohort enrolled into the earlier study (ClinicalTrials.gov NCT04041700). Results: Between 6- and 24-month follow-up, there was no statistically significant change in free-field hearing thresholds or speech reception thresholds in noise (p = > 0.05), indicating that aided improvements were maintained up to 24 months of follow-up. Furthermore, improvements in health-related quality of life and daily hearing ability, as well as clinical and subjective measures of hearing benefit remained stable over the 24-month period. No serious adverse events were reported during extended follow-up. Conclusions: These study results provide further evidence to support the longer term clinical safety, hearing performance, and patient-related benefits of the Osia 2 System in patients with either a conductive hearing loss, mixed hearing loss, or single-sided sensorineural deafness. Trial Registration: ClinicalTrials.gov Identifier: NCT04754477. First posted: February 15, 2021.

1 February 2013 in Carbohydrate Polymers
Verified
Journal Article
Closed access
ALAaran Thomas Lewis
Aaran Thomas Lewis
KJK. Jones
K. Jones
KLK.E. Lewis
K.E. Lewis
SJS. Jones
S. Jones
PLP.D. Lewis
P.D. Lewis