Schöll S (2016)
Publication Language: English
Publication Type: Thesis
Publication year: 2016
Publisher: Friedrich-Alexander-Universität Erlangen-Nürnberg
City/Town: Erlangen
Pages Range: 106
URI: https://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/8004
Cell cultures are monitored to develop new drugs, to find efficient ways to produce
vaccines and to perform toxicity tests. The cells are cultivated in an incubator and
the monitoring steps such as the acquisition of images and the counting of cells
are often done outside. As part of a research project, novel bright field miniature
microscopy prototypes were developed. These prototypes were designed to work
inside the incubator, and hence, they need to be very small.
In this thesis, image processing methods for these systems (at different development
stages) are presented. These methods made the systems usable for cell monitoring
in an incubator. This is a main contribution of the thesis. Our analyses of
the system and its components helped to improve the development of the systems.
A calibration procedure and algorithms for adjusting the illumination and the focus
position of these systems are introduced. Moreover, the proposed preprocessing
steps such as illumination correction and contrast enhancement improved the image
quality.
An image processing library and a cell monitoring software using the library were
developed. An algorithm for counting cells in images of the prototype system was
included in the image processing library. Features for viability determination were
investigated and also included in the library.
Another main contribution is related to all bright field microscopes. They have
the following effect in common: Focusing of very thin (phase) objects differs from
focusing of objects that are thicker and less transparent for light. This effect is
investigated in detail, explained, and the calculation of different useful focus positions
for phase objects is derived. The optical focus position can be used for applications
such as phase retrieval. Slightly defocused cell images with a maximum in contrast at
small details can be useful for applications such as cell segmentation or cell analysis.
Strongly defocused cell images with a maximum in contrast for the cell borders can
be used for applications such as cell detection.
APA:
Schöll, S. (2016). Cell Culture Monitoring with Novel Bright Field Miniature Microscopy Prototypes (Dissertation).
MLA:
Schöll, Simon. Cell Culture Monitoring with Novel Bright Field Miniature Microscopy Prototypes. Dissertation, Erlangen: Friedrich-Alexander-Universität Erlangen-Nürnberg, 2016.
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