Papers by Robert H Eikelboom
The Laryngoscope, Jun 30, 2007
Objective: Manual piston malcrimping in stapedotomy may be the major cause of the occurrence of t... more Objective: Manual piston malcrimping in stapedotomy may be the major cause of the occurrence of the significant, interindividual variations of postoperative air-bone gap (ABG), air-bone gap closures (ABGC), and postoperative recurrences of conductive hearing loss. To eliminate the effects of manual crimping on stapedotomy outcomes, the selfcrimping, shape memory alloy Nitinol stapes piston was investigated and hearing evaluated. Study design: Prospective, preliminary case-control study in a tertiary care referral center. Methods: Sixteen patients with otosclerosis undergoing reversed stapedotomy using the Nitinol stapes piston were matched to reference patients out of our conventional titanium piston database. The effects of the self-crimping Nitinol piston on the postoperative ABGC, the postoperative air-bone gap (ABG) variations, and the postoperative short-term hearing results were investigated 3, 6 and 9 months postoperatively. These data were statistically compared with the results of the control patients in our titanium stapes piston database. Results: The mean postoperative ABG and the interindividual variations of the postoperative ABG were significantly smaller in the Nitinol group, the extent of ABGC greater in the Nitinol piston group, but not significant. The postoperative short-term stability of ABGC was similar in both groups. No infections or adverse reactions occurred during follow-up. Conclusion: Our preliminary results suggest that the self-crimping shape memory alloy Nitinol stapes piston eliminates the limitations of manual malcrimping in stapedotomy, thus optimising the surgical procedure. This allows reliable, safe, and consistent air-bone-gap closure in patients with otosclerosis up to 1 year after surgery.
Cochlear implants international, 2016
To evaluate the clinical utility of the City University of New York sentence test in a cohort of ... more To evaluate the clinical utility of the City University of New York sentence test in a cohort of post-lingually deafened cochlear implants recipients over time. 117 post-lingually deafened, Australian English-speaking CI recipients aged between 23 and 98 years (M = 66 years; SD = 15.09) were recruited. CUNY sentence test scores in quiet were collated and analysed at two cut-offs, 95% and 100%, as ceiling scores. CUNY sentence scores ranged from 4% to 100% (M = 86.75; SD = 20.65), with 38.8% of participants scoring 95% and 16.5% of participants reaching the 100% scores. The percentage of participants reaching the 95% and 100% ceiling scores increased over time (6 and 12 months post-implantation). The distribution of all post-operative CUNY test scores skewed to the right with 82% of test scores reaching above 90%. This study demonstrates that the CUNY test cannot be used as a valid tool to measure the speech perception skills of post-lingually deafened CI recipients over time. This m...
Journal of the American Academy of Audiology, 2016
Poor follow-up compliance from school-based hearing screening typically undermines the efficacy o... more Poor follow-up compliance from school-based hearing screening typically undermines the efficacy of school-based hearing screening programs. Onsite diagnostic audiometry with automation may reduce false positives and ensure directed referrals. To investigate the validity and time efficiency of automated diagnostic air- and bone-conduction audiometry for children in a natural school environment following hearing screening. A within-subject repeated measures design was employed to compare air- and bone-conduction pure-tone thresholds (0.5-4 kHz), measured by manual and automated pure-tone audiometry. Sixty-two children, 25 males and 37 females, with an average age of 8 yr (standard deviation [SD] = 0.92; range = 6-10 yr) were recruited for this study. The participants included 30 children who failed on a hearing screening and 32 children who passed a hearing screening. Threshold comparisons were made for air- and bone-conduction thresholds across ears tested with manual and automated audiometry. To avoid a floor effect thresholds of 15 dB HL were excluded in analyses. The Wilcoxon signed ranked test was used to compare threshold correspondence for manual and automated thresholds and the paired samples t-test was used to compare test time. Statistical significance was set as p ≤ 0.05. 85.7% of air-conduction thresholds and 44.6% of bone-conduction thresholds corresponded within the normal range (15 dB HL) for manual and automated audiometry. Both manual and automated audiometry air- and bone-conduction thresholds exceeded 15 dB HL in 9.9% and 34.0% of thresholds, respectively. For these thresholds, average absolute differences for air- and bone-conduction thresholds were 6.3 (SD = 8.3) and 2.2 dB (SD = 3.6) and they corresponded within 10 dB across frequencies in 87.7% and 100.0%, respectively. There was no significant difference between manual and automated air- and bone-conduction across frequencies for these thresholds. Using onsite automated diagnostic audiometry for children who fail hearing screening may improve the efficacy of school-based screening programs by reducing false positives and ensuring directed referrals for audiological or medical intervention or both.
Telemedicine and Electronic Medicine, 2015
Australian and New Zealand Journal of Ophthalmology
INTRODUCTION Retinal images are taken routinely for the diagnosis and recording of ophthalmic pat... more INTRODUCTION Retinal images are taken routinely for the diagnosis and recording of ophthalmic pathologies. With the increasing amount of computing and imaging processing power it has become easier to analyse serial images taken over many years. Objective measurements can be ...
Telemedicine and e-Health, 2015
This study determined the accuracy of pure tone air conduction (AC) thresholds obtained using a s... more This study determined the accuracy of pure tone air conduction (AC) thresholds obtained using a synchronous telemedicine approach without a sound booth in a rural South African community. The global need for increased hearing healthcare currently far exceeds the capacity for delivering these services, especially in developing countries. A tele-audiology approach using a portable diagnostic audiometer could provide the solution, enabling hearing assessments to be conducted remotely and without a sound booth. Hearing thresholds in a sound booth and natural environment were obtained from an initial sample of 20 adults (age range, 19-63 years; mean age, 50±13 years; 55% female), recruited from a rural agricultural community. A subgroup of 10 adults (20 ears) volunteered for the telemedicine threshold testing. AC thresholds (250-8,000 Hz) were determined and subsequently compared in these environments. Typical threshold variability was determined using test-retest correspondence as a reference for the threshold correspondence using a telemedicine mode. Test-retest threshold correspondence in the booth and natural environments was within±5 dB in 96.7% and 97.5% of comparisons, respectively. No significant differences were obtained in AC hearing thresholds determined in the telemedicine configuration compared with those recorded in the gold standard booth environment. Threshold correspondence between the telemedicine compared with booth and natural environments were within±5 dB in 82% and 85% of comparisons, respectively. The current study demonstrates the validity of using synchronous telemedicine for conducting hearing assessments in a remote rural agricultural community without a sound booth.
Studies in Health Technology and Informatics, 2012
The history of telemedicine is at times presented to commence in the 20 th century. Events in Cen... more The history of telemedicine is at times presented to commence in the 20 th century. Events in Central Australia in 1874 show that the history goes further back, when the newly constructed telegraph played an important telemedicine role not only in enabling care for a wounded person, but also in uniting a dying man with his wife 2000 kilometres away. Innovation with the tools at hand has proven to be effective to bridge the tyranny of distance in the delivery of health care.
Otology & Neurotology, 2013
To study the benefits of hearing preservation surgery in cochlear implantation after 2 years. A r... more To study the benefits of hearing preservation surgery in cochlear implantation after 2 years. A retrospective cohort study. Performed at a single academic institution between 2008 and 2010 Thirteen patients (1 bilateral): 43% male and 57% female subjects. Mean age at surgery was 51 years (range, 32-72 yr). Average duration of deafness was 25 years (range, 5-62 yr). Hearing preservation cochlear implantation surgery performed with the Med-El FlexEAS electrode. Pure tone thresholds, speech perception in quiet and noise and quality of life (Abbreviated Profile of Hearing Aid Benefit [APHAB] and Glasgow Hearing Aid Benefit [GHABP Scales] up to and including 2 years after surgery. At the first postoperative audiogram, the hearing preservation rate was 100% (complete (42.9%), partial (50%), and minimal (7.1%)). After 24 months, the breakdown was complete (25%), partial (12.5%), minimal (37.5%) and complete loss (12.5%). There was a trend in improvement in all areas of APHAB) with significant improvements in the background noise and reverberation categories as well as the global scores. The GHABP scores showed high levels of use, benefit, and low levels of residual disease. Hearing preservation can be achieved in the short term but deteriorates with time over the medium term at a rate greater than that can be expected with the natural progression of the disease. Patients show benefits in speech outcomes and quality of life regardless of whether hearing preservation was achieved in the medium term.
The Annals of Otology Rhinology Laryngology, 2003
ABSTRACT The mean rupture pressure of the porcine tympanic membrane (TM) was measured in 9 specim... more ABSTRACT The mean rupture pressure of the porcine tympanic membrane (TM) was measured in 9 specimens. Pressure was delivered gradually into the external ear canal of an excised piece of temporal bone, via a syringe and polyurethane tubing attached to the canal. Tympanometry was used to ascertain the structural integrity of the TM before pressure delivery. Rupture pressure was defined to be that point at which a sudden drop occurred in the overpressure in the ear canal, as measured by a pressure gauge. From the results, we concluded that the mean rupture pressure for the porcine TM is 1.2 +/- 0.3 atm. This is of the same order of magnitude as and slightly less than pressures obtained for the human TM.
This study aimed to gauge the effect of the patient's eye movement during Photo Refractive Kerate... more This study aimed to gauge the effect of the patient's eye movement during Photo Refractive Keratectomy (PRK) on post- operative vision. A computer simulation of both the PRK procedure and the visual outcome has been performed. The PRK simulation incorporated the pattern of movement of the laser beam to perform a given correction, the beam characteristics, an initial corneal profile, and an eye movement scenario; and generated the corrected corneal profile. The regrowth of the epithelium was simulated by selecting the smoothing filter which, when applied to a corrected cornea with no patient eye movement, produced similar ray tracing results to the original corneal model. Ray tracing several objects, such as letters of various contrast and sizes was performed to assess the quality of the post-operative vision. Eye movement scenarios included no eye movement, constant decentration and normally distributed random eye movement of varying magnitudes. Random eye movement of even small amounts, such as 50 microns reduces the contrast sensitivity of the image. Constant decentration decenters the projected image on the retina, and in extreme cases can lead to astigmatism. Eye movements of the magnitude expected during laser refractive surgery have minimal effect on the final visual outcome.
Journal of telemedicine and telecare, Jan 14, 2015
Access to ear and hearing health is a challenge in developing countries, where the burden of disa... more Access to ear and hearing health is a challenge in developing countries, where the burden of disabling hearing loss is greatest. This study investigated community-based identification of hearing loss using smartphone hearing screening (hearScreen™) operated by community health workers (CHWs) in terms of clinical efficacy and the reported experiences of CHWs. The study comprised two phases. During phase one, 24 CHWs performed community-based hearing screening as part of their regular home visits over 12 weeks in an underserved community, using automated test protocols employed by the hearScreen™ smartphone application, operating on low-cost smartphones with calibrated headphones. During phase two, CHWs completed a questionnaire regarding their perceptions and experiences of the community-based screening programme. Data analysis was conducted on the results of 108 children (2-15 years) and 598 adults (16-85 years). Referral rates for children and adults were 12% and 6.5% respectively....
Ophthalmic surgery
We introduce a new method to examine the retinal nerve fiber layer (RNFL) that may detect early c... more We introduce a new method to examine the retinal nerve fiber layer (RNFL) that may detect early changes in its structure due to glaucoma. Viewed in the conventional manner, in a plane perpendicular to the retina, we get an estimation of the structural integrity of the RNFL. Viewed from a plane parallel to the retina, the RNFL forms a contour surface of hills and valleys. In our method red free fundus slides are digitally acquired. A waveform, representing a topographic profile cut through the resulting representation of the RNFL contour surface, was analyzed using Fourier's transform. Three cycles/mm in the Fourier power spectrum was used as an arbitrary cutoff to discriminate normal from glaucomatous RNFL. The Fourier power spectrum from normal RNFL was shifted to higher spatial frequencies, while the power spectrum from glaucomatous RNFL was shifted to lower spatial frequencies. Thus, Fourier Analysis can reveal information about such a wave form which is not obvious by visual inspection or by densitometric techniques. This method may allow for an even earlier diagnosis of injury to the optic nerve due to glaucoma.
Ophthalmic Technologies X, 2000
ABSTRACT This study aimed to gauge the effect of the patient's eye movement during Photo ... more ABSTRACT This study aimed to gauge the effect of the patient's eye movement during Photo Refractive Keratectomy (PRK) on post- operative vision. A computer simulation of both the PRK procedure and the visual outcome has been performed. The PRK simulation incorporated the pattern of movement of the laser beam to perform a given correction, the beam characteristics, an initial corneal profile, and an eye movement scenario; and generated the corrected corneal profile. The regrowth of the epithelium was simulated by selecting the smoothing filter which, when applied to a corrected cornea with no patient eye movement, produced similar ray tracing results to the original corneal model. Ray tracing several objects, such as letters of various contrast and sizes was performed to assess the quality of the post-operative vision. Eye movement scenarios included no eye movement, constant decentration and normally distributed random eye movement of varying magnitudes. Random eye movement of even small amounts, such as 50 microns reduces the contrast sensitivity of the image. Constant decentration decenters the projected image on the retina, and in extreme cases can lead to astigmatism. Eye movements of the magnitude expected during laser refractive surgery have minimal effect on the final visual outcome.
Games for Health Journal, 2012
Hearing loss resulting from overexposure to entertainment-related sounds is a modern concern. &am... more Hearing loss resulting from overexposure to entertainment-related sounds is a modern concern. "Epic Ear Defence" places the player in the three-dimensional environment of the ear canal and challenges the player to defend the ear from various noises, to delay the onset of noise-related hearing loss.
To determine if a smartphone application could be used as a calibrated screening audiometer with ... more To determine if a smartphone application could be used as a calibrated screening audiometer with real-time noise monitoring for school screening using automated test sequences. The investigation comprised three studies. Study 1 evaluated calibration accuracy across four Samsung S5301 smartphones (Android v4.0.4) using commercial Sennheiser HD202 headphones. Study 2 involved referencing smartphone microphone sensitivity to narrowband noise intensity as measured in octave bands by a sound-level meter between 30 and 75 dB SPL (5 dB increments). Study 3 compared screening outcomes of smartphone based and conventional hearing screening. Study 2: 15 normal-hearing subjects (age range, 18-22 years; all female). Study 3: 162 children (324 ears) aged 5 to 7 years. Smartphone calibration at 20, 30, and 40 dB was within 1 dB of recommended reference equivalent thresholds levels. Microphone calibration for noise monitoring had maximum variability across phones of 0.9, 0.6, and 2.9 dB at 1, 2, and 4 kHz, respectively, from reference intensities (30 to 75 dB SPL). Screening outcomes demonstrated no significant difference between smartphone and conventional audiometry with an overall referral rate of 4.3% and 3.7%, respectively. The newly developed smartphone application can be accurately calibrated for audiometry with valid real-time noise monitoring, and clinical results are comparable to conventional screening.
Annals of Otology, Rhinology & Laryngology, 2003
ABSTRACT The mean rupture pressure of the porcine tympanic membrane (TM) was measured in 9 specim... more ABSTRACT The mean rupture pressure of the porcine tympanic membrane (TM) was measured in 9 specimens. Pressure was delivered gradually into the external ear canal of an excised piece of temporal bone, via a syringe and polyurethane tubing attached to the canal. Tympanometry was used to ascertain the structural integrity of the TM before pressure delivery. Rupture pressure was defined to be that point at which a sudden drop occurred in the overpressure in the ear canal, as measured by a pressure gauge. From the results, we concluded that the mean rupture pressure for the porcine TM is 1.2 +/- 0.3 atm. This is of the same order of magnitude as and slightly less than pressures obtained for the human TM.
Noise and Health, 2013
To determine whether the Cheers for Ears Program on noise induced hearing loss prevention was eff... more To determine whether the Cheers for Ears Program on noise induced hearing loss prevention was effective in improving current knowledge of noise impact of personal listening devices on hearing, and in changing self-reported listening behavior of primary school students aged between 9 years and 13 years. A survey study was implemented at participating primary schools. Schools represented various levels of socio-economic status. Informed consent (parents and teachers) and informed assent (pupils) were obtained. All pupils participated in two interactive sessions (the second 6 weeks after first) and only those who provided assent and consent were surveyed at three points during the study: Prior to the first session (baseline), directly post-session and at 3 months post-session. A total of 318 pupils were surveyed. The median age of the participants was 11 years (nearly 50% of the total cohort). Significant changes are reported in their knowledge about hearing and in listening behavior of the participants as measured by pre- and post-measurement. The changes in behaviors were stable and sustained at 3 months post-intervention survey point and the success of the program can be attributed to the multimodal interactive nature of the sessions, the spacing of the sessions and the survey points. Wide-ranging support from schools and departments also played a role. The pilot Cheers for Ears Program is effective in increasing knowledge on the harmful effects of noise and therefore, it may prevent future noise-induced hearing loss.
International Journal of Audiology, 2013
Objective: To validate the air and bone conduction AMTAS automated audiometry system. Design: Pro... more Objective: To validate the air and bone conduction AMTAS automated audiometry system. Design: Prospective study. Test-retest reliability was determined by assessing adults with AMTAS air and bone conduction audiometry. Accuracy was determined by comparing AMTAS and manual audiometry conducted on adults. AMTAS testing was conducted in a quiet room and manual audiometry in a sound booth. Study Sample: Ten participants for test-retest reliability tests and 44 participants to determine accuracy were included. Participants had varying degrees of hearing loss. Results: For test-retest reliability the overall difference in air conduction hearing thresholds (n=119) was 0.5dB. The spread of differences (standard deviation of absolute differences) was 4.9dB. For bone conduction thresholds (n=99) the overall difference was -0.2dB, and the spread of differences 4.5dB. For accuracy the overall difference in air conduction hearing thresholds (n=509) between the two techniques was 0.1dB. The spread of differences was 6.4dB. For bone conduction thresholds (n=295) the overall difference was 0dB, and the spread of differences 7.7dB. Conclusions: Variations between air and bone conduction audiometry for automated and manual audiometry were within normally accepted limits for audiometry. However, AMTAS thresholds were elevated but not significantly different compared to other contemporary studies that included an automated audiometer.
IEEE Transactions on Medical Imaging, 1999
The registration of retinal images is required to facilitate the study of the optic nerve head an... more The registration of retinal images is required to facilitate the study of the optic nerve head and the retina. The method we propose combines the use of mutual information as the similarity measure and simulated annealing as the search technique. It is robust toward large transformations between the images and significant changes in light intensity. By using a pyramid sampling approach combined with simulated reannealing we find that registration can be achieved to predetermined precision, subject to choice of interpolation and the constraint of time. The algorithm was tested on 49 pairs of stereo images and 48 pairs of temporal images with success.
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Papers by Robert H Eikelboom