Biophotonics I W. Petrich

Transcription

1 Biophotonics I W. Petrich Slides of lecture #13 January 18 th, Lecture Biophotonics I will be credited with 2 CP subject to successfully passing the exam There will be a written exam ( Klausur ) on February 1st 2016 In order to participate in the examination (Klausur), you need to register before January 31 st at: Prof. Dr. Petrich Biophotonics I (WS 2015/16) 1

2 SUMMARY of lecture#12 ( ) II.2.3 Diffusion approximation and diffusion equation approximations to Boltzmann equ.: (1) II.2.4. Monte-Carlo methods (2) over mean free path length (3) Multipole expansion: diffusion coefficient reduced scattering coefficient Prof. Dr. Petrich Biophotonics I (WS 2015/16) 2

3 SUMMARY of lecture#12 ( ) II.2.3 Diffusion approximation and diffusion equation approximations to Boltzmann equ.: (1) II.2.4. Monte-Carlo methods (2) over mean free path length (3) Multipole expansion: diffusion coefficient II.3.2 sizes in biology reduced scattering coefficient II.3. Mie scattering in tissue II.3.1 Scattering coefficients revisited Figures from: omlc.ogi.edu, en.wikipedia.org, nano.med.umich.edu 3

4 Biophotonics I II.3 Mie scattering in tissue II.3.3. examples: skin Mie scattering from 2.8 µm diam., cylindrical collagen fiber bundles n p =1.46, n med =1.35, f v =0.21 Rayleigh contribution 50 nm spheres mimicing ultrastructure in collagen fibrils n p =1.50, n med =1.35, f v =0.21 full Mie theory Prof. Dr. Petrich Biophotonics I (WS 2015/16) 5

5 II.4 optical coherence tomography Prof. Dr. Petrich Biophotonics I (WS 2015/16) 8

6 II.4 optical coherence tomography Prof. Dr. Petrich Biophotonics I (WS 2015/16) 9

7 II.4 optical coherence tomography Patient with Stargardt s disease. (A) Color fundus photograph; (B) late-phase fluorescein angiogram indicating UHR-OCT scan direction (arrow); (C) UHR-OCT image; (D, E) two-fold magnification of framed part of (C) show interface of the intact and impaired photoreceptor layer area (red arrows). Transverse PR loss was 4320 μm resulting in 0.4 (20/50) VA. ONL: outer nuclear layer; ELM: external limiting membrane; IS PR: inner segment, photoreceptor layer; OS PR: outer segment, photoreceptor layer; RPE: retinal pigment epithelium. Central foveal thickness was 69 μm. E. Ergun et al., Invest. Ophthalmol. Vis. Sci. 46 (2005) , doi: /iovs

8 II.4 optical coherence tomography Prof. Dr. Petrich Biophotonics I (WS 2015/16) 11

9 II.4 optical coherence tomography Patient OFDI-02 Images of a Distal Right Coronary Artery Thin-Capped Fibroatheroma (A) Fly-through view (distal-proximal), demonstrates a circumferential lipid-rich lesion with abundant macrophages, partially covered by the stent. (B) An optical frequency domain imaging (OFDI) cross-sectional image obtained at location of white arrowheads in A and dotted line in Figure 3D, shows a circumferential lipid pool (L). Thin cap sites (black arrowheads) can be identified at multiple locations within the cross-sectional image. Macrophages (green arrowheads) and cholesterol crystals (red arrows) can also be seen. Tick marks, 1 mm. *Guide wire artifact. G.J. Tearney et al., J Am Coll Cardiol Img 1 (2008) , doi: /j.jcmg

10 Written examination on February 1 st, 2016, 9:15-10:45h in INF 308, HS2 The complete lecture will be subject to examination (incl. today). You are allowed to bring one single DIN A4 sheet with your hand-written notes on both sides of the sheet and a simple pocket calculator. cell phones, smart phones, etc or network access of any kind is not permissible. We will start with the exam at 9:15h sharply. You need to have registered at Prof. Dr. Petrich BIOPHOTONICS II SS 2016, Mondays 9-11, Chapter III: Biospectroscopy Chapter IV: Lasers in Medicine Prof. Dr. Petrich Biophotonics I (WS 2015/16) 13