Biophotonics II general remarks

Transcription

1 general remarks BIOPHOTONICS I (WS 2017/18) I. Imaging Systems human vision microscopy II. Light Scattering Mie scattering light propagation in tissue BIOPHOTONICS II (SS 2018) III. Biospectroscopy Fluorescence spectroscopy Phosphorescence, bio- and chemiluminescence Vibrational spectroscopy IV. Lasers in medicine Laser interaction with tissue Applications Literature: Bergmann-Schäfer, Optik (Walter de Gruyter) E. Hecht, Optik (Addison-Wesley) J. Bille, W. Schlegel, Medizinische Physik 3 (Springer) P.N. Prasad, Biophotonics (Wiley) T. Vo-Dinh, Biomedical Photonics Handbook (CRC Press) V.V Tuchin, Handbook of Optical Biomedical Diagnostics (SPIE Press) G.G. Hammes, Spectroscopy for the biological sciences (Wiley) J.R. Lakowicz, Principles of Fluorescence Spectroscopy (Springer) It is NOT required to have attended the Biophotonics I lecture prior to visiting Biophotonics II. Lecture Biophotonics II will be credited with 2 CP subject to successfully passing the written exam. If you intend to obtain credit points, i.e. to participate in the exam, you will have to register at: Prof. Dr. Petrich Biophotonics II (SS 2018) 1

2 general remarks Klausur : July 23 rd, 2018, 9:15-10:45 h registration: Please bring your own, completely empty (!) white paper sheets Allowed: - 1 DIN A4 page with hand-written information such as formulas etc. (both sides are o.k.) - Pencil, etc., simple pocket calculator (not on smart phone, ipad and such!) - Brain Not allowed: - Internet connection of any kind - Smart phones, cell phone, ipads etc., notebooks, netbooks etc. - Your neighbor s solutions Personal advice: 1.) be on time 2.) carefully read the question, then think, then write Prof. Dr. Petrich Biophotonics II (SS 2018) 2

3 lecture #10 (July 2 nd, 2018): summary IV.4. photothermal interaction absorption generation of heat (i.c., i.s.c., vibrational relaxation) heat equation heat transport T [ C] effect duration laser > 40 Enzymes damage, oedema, for long exposure times cell death > 60 Coagulation, (further) denaturing of proteins, nectrosis > 90 Vaporization, evaporation/boiling of water ( photothermal ablation ) ms cw, ms s Nd:YAG Ar +, Kr +, CO 2, diodes, Er:YAG, Ho:YAG > 150 carbonisation µs ms Application examples: > 300 Melting ( tissue welding) µs ms - photothermal therapy (PTT) - Port wine stain removal esp. with nanoparticles (experimental) - Laser tissue welding - photocoagulation of retina - Laser hair removal (targets (melanin, hemoglobin + heat transfer) melanin in follicle) - Diabetic retinopathy - Non-profliferating (leaks): focal laser photocoagulation - Prolifertaing (neovascularization): panretinal laser photocoagulation - Age-related macular degeneration (AMD) Prof. Dr. Petrich Biophotonics II (SS 2018) 3

4 IV. Lasers in medicine IV.6. photodisruption and plasmainduced interaction IV.5. photoablation IV.4. photothermal interaction IV.3. photochemical interaction Prof. Dr. Petrich Biophotonics II (SS 2018) 4

5 photoablation Prof. Dr. Petrich Biophotonics II (SS 2018) 5

6 photoablation Aus: Bille, Schlegel, Medizinische Physik Band III Prof. Dr. Petrich Biophotonics II (SS 2018) 6

7 photoablation Prof. Dr. Petrich Biophotonics II (SS 2018) 7

8 corneal epithelium Bowman s layer corneal stroma Descement s membran corneal endothelium air aqueous humor anterior chamber Biophotonics II photoablation cornea Prof. Dr. Petrich Biophotonics II (SS 2018) 8

9 photoablation Flap Surgery (LASIK) Surface Surgery (LASEK, Epi-LASIK) Eye Pain after Surgery Functional Vision Recovery Stable Refraction Corneal Scarring Risk Dry Eyes Symptoms Risk of Complications Minimal (may last up to 12 hours after surgery) Earlier (Less that 24 hours) Earlier (1 to 6 weeks) Minimal (Less than 1%) More risk (may last more than 6 months) More risk Flap issues: Flap wrinkles, Epithelial ingrowth, Flap melt Moderate to Severe (may last up to 72 hours after surgery) Later (3 to 7 days) Later (3 weeks to months) Greater (1 to 2 %) Less risk (lasts for 1 to several weeks) Less risk In general, safer than LASIK. Best For Most patients Patients with thin corneas or large pupils, contact sports Prof. Dr. Petrich Biophotonics II (SS 2018) 9

10 laser tissue interaction IV.6. plasmainduced interaction & photodisruption Prof. Dr. Petrich Biophotonics II (SS 2018) 10

11 plasma-induced laser ablation and photodisruption aus: J. Bille, W. Schlegel, Medizinitechnik, Bd. 3, Springer Verlag Prof. Dr. Petrich Biophotonics II (SS 2018) 11

12 plasma-induced laser ablation and photodisruption aus: J. Bille, W. Schlegel, Medizinitechnik, Bd. 3, Springer Verlag Prof. Dr. Petrich Biophotonics II (SS 2018) 12

13 optical tweezer K.C. Neumann et al., Cell, Vol. 115, , November 14, 2003 Prof. Dr. Petrich Biophotonics II (SS 2018) 13