liu.seSearch for publications in DiVA
Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Fibre-optic array for curvature assessment: application in otitis diagnosis
Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation. Linköping University, The Institute of Technology.
Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, The Institute of Technology.ORCID iD: 0000-0002-9267-2191
Linköping University, Department of Biomedical Engineering, Medical Informatics. Linköping University, The Institute of Technology.ORCID iD: 0000-0002-9091-4724
Linköping University, Department of Biomedical Engineering, Physiological Measurements. Linköping University, The Institute of Technology.
Show others and affiliations
2004 (English)In: Medical & Biological Engineering & Computing, ISSN 0140-0118, Vol. 42, no 2, 245-252 p.Article in journal (Refereed) Published
Abstract [en]

A contact-free sensor consisting of two parallel optical-fibre arrays was designed to assess surface shapes of diffusely scattering media. By sequentially illuminating objects using one fibre array and detecting the diffusely back-scattered photons by the other, a source-detector intensity matrix was formed, where the matrix element (i, j) was the intensity at detector j when light source i was excited. Experimental data from convex and concave polyacetal plastic surfaces were recorded. A mathematical model was used for simulating source-detector intensity matrices for the surfaces analysed in the experiments. Experimental results from the system were compared with the theoretically expected results provided by the mathematical model. The shape and relative amplitude showed similar behaviour in the experiments and simulations. A convex/concave discriminator index D, representing the detected intensity difference between two source-detector separations, was defined. The relative dynamic range of D, defined as the difference between the maximum and the minimum divided by the mean of the index, was 1.37 for convex surfaces and 0.68 for concave surfaces, at a measuring distance of 4.5mm. The index D was positive for convex surfaces and negative for concave surfaces, which showed that the system could distinguish between convex and concave surfaces, an important result for the diagnosis of otitis media.

Place, publisher, year, edition, pages
2004. Vol. 42, no 2, 245-252 p.
Keyword [en]
Diffuse reflection, Optical imaging, Otitis media, Surface shape identification
National Category
Medical Laboratory and Measurements Technologies
Identifiers
URN: urn:nbn:se:liu:diva-13008DOI: 10.1007/BF02344638OAI: oai:DiVA.org:liu-13008DiVA: diva2:17658
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2014-10-08
In thesis
1. Optical Methods for Tympanic Membrane Characterisation: Towards Objective Otoscopy in Otitis Media
Open this publication in new window or tab >>Optical Methods for Tympanic Membrane Characterisation: Towards Objective Otoscopy in Otitis Media
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Otitis media, which is an upper respiratory tract infection that affect the middle ear, is the second most common disease in childhood, outnumbered in prevalence only by the common cold. Diagnosis of middle ear inflammation is often performed in the primary healthcare where the normal procedure involves anamnesis and physical examination of the tympanic membranes (TM) of the patient, usually be means of otoscopy. The general aim of this thesis was to develop optical methods that enable quantification of TM characteristics associated with otitis media. Diffuse reflectance spectroscopy was applied to quantify TM erythema using previously suggested erythema detection algorithms. Healthy TM:s were significantly distinguished from TM:s with induced erythema (p < 0.01) and from TM:s in ears with mucous middle ear effusion (p < 0.05). A new technique for surface shape assessment based on an on-axis dual fibre array incorporated in an otoscope was developed and evaluated in ear models and on tympanic membranes from harvested temporal bones. The technique utilises the combined effects of source-detector fibre separation and fibre-to-sample distance on the detected light intensity.

Optical phantoms, both polyacetal plastic solids and latex membranes, were utilised to demonstrate the ability of the surface shape assessment technique to differentiate between convex and concave surfaces – as a bulging tympanic membrane is typically associated with acute otitis media whereas a retracted eardrum is associated with otitis media with effusion. Monte Carlo simulations of the surface shape data were performed in order to validate the experimental results with a theoretical model that are consistent with light transport theory. Retracted and bulging tympanic membranes from harvested temporal bones could be separated with a single measurement, given that variations in measurement distance were accounted for and that measurement from normally positioned tympanic membranes were used for signal normalization. In conclusion, the studies implicate that for individual otitis diagnosis, the hyperaemic tympanic membrane was separated from the healthy by application of erythema indices using diffuse reflectance spectroscopy. Moreover, bulging and retracted positions of the tympanic membrane were separable by means of the source-detector intensity matrix. For further clinical studies it is reasonable to assume that data from both methods are needed for diagnosis.

Place, publisher, year, edition, pages
Institutionen för medicinsk teknik, 2008. 97 p.
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1173
Keyword
Optical Methods, Spectroscopy, Surface Curvature, Monte Carlo, Tympanic Membrane, Otitis Media
National Category
Medical Laboratory and Measurements Technologies
Identifiers
urn:nbn:se:liu:diva-11246 (URN)978-91-7393-933-1 (ISBN)
Public defence
2008-04-11, Berzeliussalen, Ingång 65, plan 9, Campus US, Linköpings universitet, Linköping, 13:00 (English)
Opponent
Supervisors
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2009-05-14
2. Optical methods for tympanic membrane colour and shape assessment
Open this publication in new window or tab >>Optical methods for tympanic membrane colour and shape assessment
2004 (English)Licentiate thesis, comprehensive summary (Other academic)
Abstract [en]

Otitis media is one of the most common diseases of childhood. Increasing antibiotic resistance has lead to awareness of the importance of the diagnostic accuracy in otitis media. The recommended treatment of acute otitis media (AOM) involves antibiotics whereas in otitis media with effusion (OME) it does not. Hence, there is a need for new technology that can help separating between the two (and healthy conditions). The work in this thesis suggests a combination of diffuse reflectance spectroscopy and a new technique for surface-curvature measurement as a tool for assisted diagnosis in otitis media.

Diffuse reflectance spectroscopy was applied to estimate the degree of tympanic membrane erythema by means of two erythema detection algorithms from the literature. Measurements were performed in children with otitis media with effusion (15 ears) and in a healthy reference group (15 ears). The children with OME were scheduled for tympanostomy tube placement, which involves perforation of the tympanic membrane. Spectroscopic recordings were performed before and after perforation of the tympanic membrane in the OME group and once in the healthy reference group. Significant differences between the erythema estimates were present between the groups (p < 0.05).

A new surface-curvature measurement system, consisting of two parallel optical fibre arrays, was designed and tested using convex and concave polyacetal plastic (delrin) objects. By sequentially illuminating the surface and detecting the backscattered light intensity, a source-detector intensity matrix was formed. A simplified mathematical model for light scattering showed similar shape and amplitude of the source-detector matrices as did the experimental results. The surface-curvature measurement system distinguishes correctly between convex and concave surfaces.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2004. 45 p.
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1098
Series
LiU-TEK-LIC, 27
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-22164 (URN)1283 (Local ID)91-7373-973-1 (ISBN)1283 (Archive number)1283 (OAI)
Available from: 2009-10-07 Created: 2009-10-07 Last updated: 2013-11-13

Open Access in DiVA

No full text

Other links

Publisher's full textLink to Ph.D. Thesis

Authority records BETA

Sundberg, MikaelBorga, MagnusKnutsson, HansJohansson, AndersStrömberg, TomasÖberg, Åke

Search in DiVA

By author/editor
Sundberg, MikaelBorga, MagnusKnutsson, HansJohansson, AndersStrömberg, TomasÖberg, Åke
By organisation
Biomedical InstrumentationThe Institute of TechnologyMedical InformaticsPhysiological Measurements
Medical Laboratory and Measurements Technologies

Search outside of DiVA

GoogleGoogle Scholar

doi
urn-nbn

Altmetric score

doi
urn-nbn
Total: 644 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf