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
In vivo determination of local skin optical properties and perfusion using a pathlength compensated spatially resolved laser Doppler flowmetry approach
Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.ORCID iD: 0000-0001-6385-6760
Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
(English)Manuscript (preprint) (Other academic)
Abstract [en]

The laser Doppler flowmetry (LDF) perfusion estimate is almost linearly related to the pathlength of the detected photons, and, consequently, sensitive to the optical properties of the tissue. Therefore, we propose an in vivo pathlength and optical property estimation method, based on diffuse reflectance and Monte Carlo simulations, that minimizes the influence of optical properties on the LDF perfusion estimate. Caucasian human skin displayed a maximrun variation of -35% in the photon pathlength between individuals in similar locations, and within individuals comparing fingertip and forearm skin. The results suggest that, using the proposed method, it is possible to minimize the influence of optical properties, thus enabling intraw and inter-individual compatisons ofLDF perfusion estimates in different organs.

National Category
Medical and Health Sciences
Identifiers
URN: urn:nbn:se:liu:diva-81359OAI: oai:DiVA.org:liu-81359DiVA: diva2:551927
Available from: 2012-09-12 Created: 2012-09-12 Last updated: 2016-08-31Bibliographically approved
In thesis
1. Photon migration in tissue: laser induced fluorescence for cancer diagnostics and influence of optical properties on microvascular Doppler spectroscopy
Open this publication in new window or tab >>Photon migration in tissue: laser induced fluorescence for cancer diagnostics and influence of optical properties on microvascular Doppler spectroscopy
2002 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Laser induced flourescence (LIF) is an "optical biopsy" method, based on the selective accumulation of fluorophores in neoplastic tissue. Two recently developed, non-photosensitizing tumor seeking carotenoporphyrins were assessed regarding tumor selectivity, and biodistribution, in experimental animals. A tumor to peritumoral ratio of 5-6:1 was seen in the background free substance related fluorescence in vivo, as well as ex vivo. Cerebral cortex and skeletal muscle displayed a low, and liver a high substance related fluorescence.

Laser Doppler flowmetry (LDF) is based on the spectral broadening of monochromatic light, that interacts with moving red blood cells in tissue. The power spectral density of the backscattered light can be processed to yield an estimate of microvascular tissue perlusion. Using a Monte Carlo simulation model of human skin, it is demonstt·ated that for a particular light delivery/detection arrangement, Doppler shifted photons that originate from the central core and peripheral parts of blood vessels of physiological dimensions, both contribute to the detected signal. Further, more than 10 times as many photons will interact with the superficial as with the deep vascular plexus. However, due to greater velocities and concentrations of the moving scatterers, the profound circulation still may yield a greater contribution to the LDF perfusion estimate.

A multiple polynomial regression method for prediction of photon pathlength and optical properties in tissue, at surlace source detector separations up to two millimeters, was developed. Using the diffuse, backscattered reflectance profile from an array of optical sensors as predictors in the model resulted in root-meansquare errors of less than three per cent for the estimated pathlength. Caucasian human skin displayed a maximum in vivo variation of ~35 % in the photon pathlength between individuals in similar locations, and within individuals comparing fingertip and forearm skin, as a result of varying optical properties.

Assuming a homogenous tissue perlusion, the pathlength variations will induce a corresponding variation in the LDF petfusion signal, which can be compensated for by linearization and pathlength normalization, making intra- and interindividual comparisons of the LDF perfusion estimate feasible.

Place, publisher, year, edition, pages
Linköping: Linköpings universitet, 2002. 123 p.
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 735
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-29435 (URN)14781 (Local ID)91-7373-179-X (ISBN)14781 (Archive number)14781 (OAI)
Public defence
2002-05-31, Administrationsbyggnadens aula, Universitetssjukhuset, Linköping, 13:15 (Swedish)
Opponent
Available from: 2009-10-09 Created: 2009-10-09 Last updated: 2012-10-08Bibliographically approved

Open Access in DiVA

No full text

Authority records BETA

Larsson, MarcusStrömberg, Tomas

Search in DiVA

By author/editor
Larsson, MarcusStrömberg, Tomas
By organisation
Department of Biomedical EngineeringThe Institute of Technology
Medical and Health Sciences

Search outside of DiVA

GoogleGoogle Scholar

urn-nbn

Altmetric score

urn-nbn
Total: 36 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