WHAT MATERIAL DID WE USE?
Based on the relative concentration of the scatterer and absorber in the skin layers and taking into account the scattering and absorption coefficients of the skin extracted from the literature, we computed the amount of each of the constitutions using Mie calculator. Table 2, shows the amount of the scatterer, absorber, and the hardener required to resemble the scattering and absorption coefficients of the skin layers.
Table 2. Concentration of scatterer, absorber and hardener in modeling the skin layers calculated by Mie theory. C, stands for concentration
The confocal gate of the presented system was measured 180 µm. Using the features described in Table 1 and Table 2, we constructed the multilayer phantom. The DF-OCT and the images taken of the phantom are given in Figure 4.
CONCLUSION
• We modelled human skin using Agarose, different sizes of polystyrene microsphere and molecular absorber.
• The preliminary results showed that the constructed phantoms could be used for evaluation of the optical properties extraction algorithm.
• A more comprehensive study is required to model the compartments of skin in each layer particularly in epidermis where it has five sub layers. Such a model can then be used for differentiating cancerous and healthy skins.
REFERENCES
[1] A. G. Podoleanu, ‘Optical coherence tomography’, Br. J. Radiol. 78, 976-988 (2005).
[2] M. Firbank and D. Delpy, ‘A design for a stable and reproducible phantom for use in near infra-red imaging and spectroscopy,’ Phys. Med. Biol. 38, 847–853 (1993).
WHAT IS DF-OCT?
We used time domain dynamic focus OCT (DF-OCT) for imaging the phantoms. With dynamic focus scheme, which is added to the time domain OCT, a wide imaging range With a high lateral resolution throughout the depth is obtained.
Figure 4. Left: Dynamic focus time domain OCT optical setup. SLD: super luminescent laser diode, PD: photodiode, C1: 2 2 coupler, PC: personal computer, BD: balance detection, CL: Collimator lens, MPC: Mirror positioning controller, MC: Motion controller, PC: polarisation controller. Right: OCT image of the multilayer phantom obtained from the DF-OCT.
[3] U. Sukowski, F. Schubert, D. Grosenick, and H. Rinneberg, ‘Preparation of solid phantoms with defined scattering and absorption properties for optical tomography’, Phys. Med. Biol. 41, 1823-1844 (1996).
[4] M. Avanaki, S. Hojjatoleslami, and A. Podoleanu, ‘Investigation of computer-based skin cancer detection using optical coherence tomography’, Journal of Modern Optics 56, 1536-1544 (2009).
Winners of Carl Zeiss Nano Image Contest Announced
After an exciting finish the winners of the first Carl Zeiss Nano Image Contest have now been selected. The winners of the four categories will each receive a pair of cinemizer Plus video glasses from Carl Zeiss.
The winners are Heinrich Badenhorst from the University of Pretoria, South Africa category Scanning Electron Microscopy (SEM), Norman Hauke and Arne Laucht of the Walter Schottky Institute of Munich Technical University, Germany category CrossBeam (FIB-SEM), Dr. Emile van Veldhoven of the TNO Research Institute in Delft, Netherlands, category Helium Ion Microscopy (HIM) and Dr. Andrey Burov of the Russian Academy of Sciences in Saratov in the category Transmission Electron Microscopy (TEM).
The Managing Director of Carl Zeiss NTS, Dr. Frank Stietz, is very pleased at the excellent response to the contest with over 120 entries: “The broad spectrum of application topics, the technical quality and the artistic composition of the nano images are fascinating. We would like to thank all participants for their entries and extend our congratulations to the winners.”
First prize in the SEM category was awarded to Heinrich Badenhorst with his image of a bizarre landscape made of graphite, captured with an ULTRA REM. With a total of 7000 points, his image received the most votes of all categories. “Our ZEISS ULTRA has allowed me to make massive progress in my research in the past year. ZEISS SEM technology helped me to uncover aspects of graphite oxidation which I have never seen before,” stresses Badenhorst, a scientist working in the field of graphite technology.
The winning image of Norman Hauke and Arne Laucht in the FIB-SEM category shows a photonic crystal, produced and captured with an NVision 40 CrossBeam Workstation. The two PhD students are delighted at their unexpected victory: “It is an honour for us to be the winners of the 2010 Carl Zeiss Nano Image Contest. This innovative and high-quality research has only been made possible by the state-of-the-art equipment at Schottky Institute, such as the nano-lithography and nano-imaging systems from Carl Zeiss. This constantly provides us with stunning views of nano worlds.”
The logos of Delft Technical University, the TNO Institute and Carl Zeiss on a surface of only 2x2 micrometers are shown in the image of Dr. Emile van Veldhoven, with which he won first prize in the HIM category.“ Our ORION helium ion microscope is the tool which enables me to create and image with extreme nanometer precision,” van Veldhoven explains.
Dr. Andrey Burov came in top in the TEM category with an artistic image of golden nanoparticles, generated with a LIBRA 120 TEM. He finds the link between technology and art in nano microscoping totally remarkable: “It is great when work brings not only results, but also esthetic pleasure. I thank Carl Zeiss for the possibility to realize my talent as an artist.”
Competition
A total of 123 microscopy images were submitted for the contest that ran from the middle of May to the end of August. After the end of the submission period, both the participants and all the visitors to the website were given the opportunity to vote for their favourite images and therefore selected the winners.
Graphite structure- H. Badenhorst (SEM) Heinrich Badenhorst
Photonic crystal – N.Hauke/
A.Laucht (FIB-SEM)
Logos – Dr
E.van Veldhoven (HIM) Golden nanoparticles - Dr A. Burov (TEM)
Microscopy Focus
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