Advanced

T-matrix computations of light scattering by red blood cells

Nilsson, Annika M. K.; Alsholm, Peter; Karlsson, Anders and Andersson-Engels, Stefan LU (1998) In Applied Optics 37(13). p.2735-2748
Abstract
The electromagnetic far field, as well as the near field, originating from light interaction with a red blood cell ~RBC! volume-equivalent spheroid, was analyzed by utilizing the T-matrix theory. This method is a powerful tool that makes it possible to study the influence of cell shape on the angular distribution of
scattered light. General observations were that the three-dimensional shape, as well as the optical thickness apparent to the incident field, affects the forward scattering. The backscattering was influenced by the shape of the surface facing the incident beam. Furthermore sphering as well as elongation of an oblate RBC into a volume-equivalent sphere or a prolate spheroid, respectively, was theoretically modeled to imitate... (More)
The electromagnetic far field, as well as the near field, originating from light interaction with a red blood cell ~RBC! volume-equivalent spheroid, was analyzed by utilizing the T-matrix theory. This method is a powerful tool that makes it possible to study the influence of cell shape on the angular distribution of
scattered light. General observations were that the three-dimensional shape, as well as the optical thickness apparent to the incident field, affects the forward scattering. The backscattering was influenced by the shape of the surface facing the incident beam. Furthermore sphering as well as elongation of an oblate RBC into a volume-equivalent sphere or a prolate spheroid, respectively, was theoretically modeled to imitate physiological phenomena caused, e.g., by heat or the increased shear stress of flowing blood. Both sphering and elongation were shown to decrease the intensity of the forward-directed scattering, thus yielding lower g factors. The sphering made the scattering pattern independent of
azimuthal scattering angle fs, whereas the elongation induced more apparent fs-dependent patterns. The light scattering by a RBC volume-equivalent spheroid was thus found to be highly influenced by the shape of the scattering object. A near-field radius rnf was evaluated as the distance to which the maximum intensity of the total near field had decreased to 2.5 times that of the incident field. It was estimated to 2–24.5 times the maximum radius of the scattering spheroid, corresponding to 12–69 mm. Because the near-field radius was shown to be larger than a simple estimation of the distance between the RBC’s in whole blood, the assumption of independent scattering, frequently employed in opticalmeasurements on whole blood, seems inappropriate. This also indicates that one cannot extrapolate the results obtained from diluted blood to whole blood by multiplying with a simple concentration factor. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
in
Applied Optics
volume
37
issue
13
pages
14 pages
publisher
OSA
external identifiers
  • Scopus:0001724232
ISSN
0003-6935
language
English
LU publication?
yes
id
d9c4345b-e4d6-444a-9443-70b5282577ac
date added to LUP
2016-06-08 15:28:31
date last changed
2016-10-30 04:48:04
@misc{d9c4345b-e4d6-444a-9443-70b5282577ac,
  abstract     = {The electromagnetic far field, as well as the near field, originating from light interaction with a red blood cell ~RBC! volume-equivalent spheroid, was analyzed by utilizing the T-matrix theory. This method is a powerful tool that makes it possible to study the influence of cell shape on the angular distribution of<br/>scattered light. General observations were that the three-dimensional shape, as well as the optical thickness apparent to the incident field, affects the forward scattering. The backscattering was influenced by the shape of the surface facing the incident beam. Furthermore sphering as well as elongation of an oblate RBC into a volume-equivalent sphere or a prolate spheroid, respectively, was theoretically modeled to imitate physiological phenomena caused, e.g., by heat or the increased shear stress of flowing blood. Both sphering and elongation were shown to decrease the intensity of the forward-directed scattering, thus yielding lower g factors. The sphering made the scattering pattern independent of<br/>azimuthal scattering angle fs, whereas the elongation induced more apparent fs-dependent patterns. The light scattering by a RBC volume-equivalent spheroid was thus found to be highly influenced by the shape of the scattering object. A near-field radius rnf was evaluated as the distance to which the maximum intensity of the total near field had decreased to 2.5 times that of the incident field. It was estimated to 2–24.5 times the maximum radius of the scattering spheroid, corresponding to 12–69 mm. Because the near-field radius was shown to be larger than a simple estimation of the distance between the RBC’s in whole blood, the assumption of independent scattering, frequently employed in opticalmeasurements on whole blood, seems inappropriate. This also indicates that one cannot extrapolate the results obtained from diluted blood to whole blood by multiplying with a simple concentration factor.},
  author       = {Nilsson, Annika M. K. and Alsholm, Peter and Karlsson, Anders and Andersson-Engels, Stefan},
  issn         = {0003-6935},
  language     = {eng},
  number       = {13},
  pages        = {2735--2748},
  publisher    = {ARRAY(0x84fb360)},
  series       = {Applied Optics},
  title        = {T-matrix computations of light scattering by red blood cells},
  volume       = {37},
  year         = {1998},
}