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Biomedical subjects

Robert H Eikelboom

Publications and source records attributed to Robert H Eikelboom.

12 recordsLinked to original sources

Retinal image analysis: concepts, applications and potential.

As digital imaging and computing power increasingly develop, so too does the potential to use these technologies in ophthalmology. Image processing, analysis and computer vision techniques are increasing in prominence in all fields of medical science, and are especially pertinent to modern ophthalmology, as it is heavily dependent on visually oriented signs. The retinal microvasculature is unique in that it is the only part of the human circulation that can be directly visualised non-invasively in vivo, readily photographed and subject to digital image analysis. Exciting developments in image processing relevant to ophthalmology over the past 15 years includes the progress being made towards developing automated diagnostic systems for conditions, such as diabetic retinopathy, age-related macular degeneration and retinopathy of prematurity. These diagnostic systems offer the potential to be used in large-scale screening programs, with the potential for significant resource savings, as well as being free from observer bias and fatigue. In addition, quantitative measurements of retinal vascular topography using digital image analysis from retinal photography have been used as research tools to better understand the relationship between the retinal microvasculature and cardiovascular disease. Furthermore, advances in electronic media transmission increase the relevance of using image processing in 'teleophthalmology' as an aid in clinical decision-making, with particular relevance to large rural-based communities. In this review, we outline the principles upon which retinal digital image analysis is based. We discuss current techniques used to automatically detect landmark features of the fundus, such as the optic disc, fovea and blood vessels. We review the use of image analysis in the automated diagnosis of pathology (with particular reference to diabetic retinopathy). We also review its role in defining and performing quantitative measurements of vascular topography, how these entities are based on 'optimisation' principles and how they have helped to describe the relationship between systemic cardiovascular disease and retinal vascular changes. We also review the potential future use of fundal image analysis in telemedicine.

Animals↗

Validation of tele-otology to diagnose ear disease in children.

OBJECTIVE: To determine if digitised still eardrum images, with a clinical history, and audiometry and tympanometry data provide sufficient information to an ear specialist to make an assessment of a patient. METHODS: 66 children (9 months to 16 years) from remote communities were assessed by an ear specialist by standard otoscopy, using a clinical history, audiometry and tympanometry. Up to five images of each ear were digitised. At a later date, the ear specialist made observations, diagnoses and recommendations for management from the images and clinical data. RESULTS: There was a significant correlation (p<0.01) between image quality and age of the subject. There were significant agreements for the clinically important observations of otorrhea, perforation, retracted tympanic membrane and atrophy of the tympanic membrane (p<0.05). There were significant agreements for the diagnoses of acute otitis media, chronic suppurative otitis media, otitis media with effusion and Eustachian tube dysfunction. The rate of recommendations for review or referral after a tele-otology assessment were between 4 and 16% higher than those in made in the field. The agreements between the various forms of advice or recommendations made in the field to those made by tele-otology were statistically significant (p<0.01). CONCLUSIONS: A tele-otology system that incorporates good quality digitised images of the tympanic membrane, audiological and tympanometric data, and a comprehensive clinical history provides the ear specialist with sufficient information to make a confident diagnose of existing middle ear disease, and provide management advice to the patients' primary care provider.

Acoustic Impedance Tests↗

In vivo performance of the Nitinol shape-memory stapes prosthesis during hearing restoration surgery in otosclerosis: a first report.

The limitations of manual prosthesis crimping in hearing restoration surgery for otosclerosis are thought to have a key role in the occurrence of incomplete postoperative elimination of conductive hearing loss and postoperative recurrences of conductive hearing loss. To eliminate manual crimping, the self-crimping, shape-memory alloy Nitinol stapes piston was introduced in nine otosclerosis patients. The results were compared with those in a database of surgeries performed with conventional titanium pistons. The effects of the self-crimping Nitinol prosthesis on the postoperative elimination of conductive hearing loss and its postoperative variations were investigated. The variations of postoperative residual conductive hearing loss were significantly smaller and the extent of conductive hearing-loss elimination greater in the Nitinol group. The mean postoperative residual conductive hearing loss was smaller in the Nitinol group. The postoperative stability of conductive hearing loss elimination was similar in both patient groups. Preliminary results suggest that the self-crimping shape-memory alloy Nitinol stapes piston overcomes the drawbacks of manual crimping in hearing restoration surgery for otosclerosis.

Adult↗

Unilateral profound hearing loss and the effect on quality of life after cerebellopontine angle surgery.

OBJECTIVE: To assess patients' quality of life after cerebellopontine angle surgery, and in particular, quality of life related to unilateral profound hearing loss. STUDY DESIGN AND SETTING: Cross-sectional in a tertiary referral center. Quality of life of 51 postoperative patients was assessed by using the Glasgow Benefit Inventory (GBI). Thirty patients with unilateral profound hearing loss who had undergone the translabyrinthine approach completed a subsequent quality-of-life questionnaire on speech discrimination and sound localization. RESULTS: Ninety-four percent of respondents to the 2nd survey reported difficulties with speech discrimination, and 97%, with sound localization. The general health and overall GBI indices correlated significantly (P < 0.01) with a number of speech and localization difficulties. CONCLUSION: Unilateral profound hearing loss may be a significant factor in a change in quality of life after cerebellopontine angle surgery. SIGNIFICANCE: Rehabilitation devices that improve discrimination and localization, and hearing preservation surgery, if indicated, should be considered for these patients.

Adult↗

Eliminating the limitations of manual crimping in stapes surgery? A preliminary trial with the shape memory Nitinol stapes piston.

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 self-crimping, 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.

Adult↗

Attitude to telemedicine, and willingness to use it, in audiology patients.

We studied the willingness of patients to use telemedicine for ear- and hearing-related appointments, and the factors that influenced their decision to participate in telemedicine. A survey was designed with questions about patient appointments, perceived advantages and barriers to telemedicine, and prior use of the Internet for health-related matters. A total of 116 patients in four audiology centres were surveyed from December 2004 to May 2005. There were 54 male and 62 female respondents; 46% of the participants were aged over 66 years. In all, 75% had not previously heard of telemedicine. The most common reasons for willingness to use telemedicine were to reduce the time waiting for an appointment and cost. The most common barrier to using telemedicine was a preference for face-to-face visits. Of those surveyed, 32% were willing to use telemedicine, 10% would sometimes be willing, 28% were unsure, and 30% were not willing. There was no relationship between willingness and age or gender, except that women over the age of 55 years were less willing. Patients who had previously heard of telemedicine and used the Internet for health-related matters, especially men, were more inclined to have a telemedicine appointment.

Aged↗

Evaluation of video-otoscopes suitable for tele-otology.

The objectives of this study were to assess the quality of digitized video-otoscopes as well as its ease of use and safety. Four video-otoscopes available in Australia were used to image 96 patients. At least 22 patients (age range 5-70 years) were imaged with each video-otoscope, and the images were stored in a JPEG format. Three experienced otolaryngologists assessed all images for quality, clarity, color accuracy, orientation of eardrum and therefore ability to make a definitive diagnosis. The grading was a five-level scale: poor, adequate, good, very good and excellent. Two telescope systems produced high quality images (>80% were adequate or better), essential for accurate diagnosis, but both were associated with increased risk for injury in unskilled hands. The MedRx video-otoscope produced high-quality images (87% were adequate or better), while the Welch Allyn Compact Video-otoscope produced poor image quality (only 40% were adequate or better). Both devices were seen to be safer to use than the telescope systems. The telescope systems and MedRx otoscope provided optimum quality images necessary for tele-otology. However, the telescope units were considered to be unsafe in unskilled hands. The MedRx can be recommended as a safe device producing high-quality images.

Adolescent↗

Pressures of the porcine tympanic membrane.

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.

Acoustic Impedance Tests↗

A tele-otology course for primary care providers.

The shortage of otolaryngologists and the high incidence of ear disease in remote areas are major problems in Australia. We have developed a multimedia course for primary care providers that incorporates material about ear anatomy and physiology, ear disease, video-otoscopy and telemedicine software. The computer-based course was followed by a practical one-day course. A multiple-choice test was given to participants before and at the end of the course and a form was used to record feedback. The course was conducted with 30 aboriginal health workers. The participants were able to obtain images of reasonable to good quality after a short period of training. There was an average improvement of about 25% in the test scores, and the feedback regarding the course was extremely positive. The CD-ROM and the Website provide a valuable resource to assist primary care providers in their care of patients with ear disorders.

Attitude of Health Personnel↗

Tele-otology: planning, design, development and implementation.

The view of the tympanic membrane of the ear provides the specialist with important information for the assessment of ear disease and for treatment planning. In rural and remote areas, the incidence of ear disease is high but access to ear specialists is limited. As part of a project to deliver tele-otoscopy services to remote Western Australia, we have investigated various aspects of a tele-otoscopy system. We found that the MedRX video-otoscope is relatively safe to use and produces images of very good quality. A confident diagnosis could be made from still images compressed to 20 kByte. Video sequences could be compressed to a ratio of 1:300. Furthermore, a software package has been developed, and we are developing a training course for health-care workers in remote areas.

Journal Article↗

Tele-otology: planning, design, development and implementation.

The view of the tympanic membrane of the ear provides the specialist with important information for the assessment of ear disease and for treatment planning. In rural and remote areas, the incidence of ear disease is high but access to ear specialists is limited. As part of a project to deliver tele-otoscopy services to remote Western Australia, we have investigated various aspects of a tele-otoscopy system. We found that the MedRX video-otoscope is relatively safe to use and produces images of very good quality. A confident diagnosis could be made from still images compressed to 20 kByte. Video sequences could be compressed to a ratio of 1:300. Furthermore, a software package has been developed, and we are developing a training course for health-care workers in remote areas.

Diagnostic Imaging↗