Optical methods in medicine

2021/2022
Programme:
Medical Physics, Second Cycle
Year:
1 in 2 year
Semester:
first or second
Kind:
optional
ECTS:
6
Language:
slovenian
Hours per week – 1. or 2. semester:
Lectures
2
Seminar
0
Tutorial
1
Lab
0
Prerequisites

Regular enrolement

Content (Syllabus outline)

Optics of biological tissues: absorption (main chromophors, optical window), elastic scattering (scattering cross section, phase function, Rayleigh and Mie regime), multiple scattering regime (transport theory, diffusion approximation, Monte Carlo), measurement of optical properties.
Diagnostic techniques: flow cytometry, diffuse reflectance, fluorescence (native, exogenous), Raman spectroscopy.
Tomographic imaging techniques: optical coherence tomography, diffused optical tomography, optoacoustic tomography, phototheramal radiometry.
Linear response of tissue to irradiation: dynamics of heat transport (time constants, perfusion), thermoelastic stress.
Photocoagulation: kinetics of protein denaturisation (laser interstitial thermotherapy, laser welding and soldering), selective photothermolysis (therapy of vascular malformations, optical screening).
Photothermal laser ablation: metrics and heuristic models, microscopic processes (phase explosion, confined boiling), screening by ablation debris, clinical examples (superficial ablation in dermatology, laser scalpel, treatment of hard tissues).
Photomechanical effects: formation of plasma and shock waves, cavitation, clinical examples (lithotripsy, eye surgery).
Photoionisation (laser keratom).
Photochemical effects: photochemical decomposition (photorefractive ceratectomy), photodynamic therapy (oncology).
Laser hazards and safety measures.

Readings

• Ashley J. Welch, Martin J.C. van Gemert, eds., Optical-Thermal Response of Laser-Irradiated Tissue, 2nd ed., Springer (Dordrecht, 2011), 958 p. ISBN: 978-90-481-8830-7
• Markof H. Niemz, Laser-Tissue Interactions; Fundamentals and Applications, 3rd ed., Springer-Verlag (Berlin, 2007), 297 p. ISBN: 978-3-540-72191-8
• L.V. Wang, H-I. Wu, Biomedical Optics; Principles and Imaging, Wiley-Interscience (Hoboken, NJ, 2007), 362 p., ISBN: 978-0-471-74304-0

Objectives and competences

Students gain fundamental knowledge of the most important optical methods for medical diagnostics, therapy, microscopy and tomography.
Competences:
Knowledge and basic understanding of processes of light interaction with tissue in UV and IR range. Knowledge and understanding of typical processes during strong laser irradiation and important therapeutic applications. Familiarity of advanced optical methods in medical diagnostics, tomography and microscopy of biological samples. Understanding of specific hazards of laser source and necessary protection.

Intended learning outcomes

Knowledge and understanding:
Obtaining knowledge about non-ionizing radiation effects on biological tissues and fundamental dependence on irradiation parameters. Obtains basic understanding of fundamental optical methods for medical diagnostics and therapy, as well as advanced microscopic and tomographic techniques. Understand laser source hazards and methods of protection.
Application:
Use and application of the fundamental physics concepts on the considered applications of medical diagnostics, therapy and microscopy.
Reflection:
Critical assessment of the use of mathematical and physical models on complex biological systems. Critical evaluation of advantages and disadvantages of various optical methods in clinical practice.
Transferable skills:
Critical synthesis of knowledge of various physics disciplines in biological systems using electrooptical systems. Ability to critically analyze apparently conflicting results in the modern literature. Understanding the problems and limitations of medical applications (e.g., ethical and statistical concepts)

Learning and teaching methods

Lectures, computational exercises, consultations.

Assessment

Oral exam
grading: 5 (fail), 6-10 (pass) (according to the Statute of UL)

Lecturer's references
  1. M. Milanič, B. Majaron. Energy deposition profile in human skin upon irradiation with a 1,342 nm Nd:YAP laser. Lasers Surg. Med., vol. 45, 8-14, 2013.
  2. B. Majaron, J.S. Nelson. Laser Treatment of Port Wine Stains. in: Optical-Thermal Response of Laser-Irradiated Tissue, A.J. Welch and M.J.C. van Gemert eds., 2nd ed., Springer, 859–914, 2011.
  3. M. Milanič, W. Jia, J. S. Nelson, B. Majaron, Numerical optimization of sequential cryogen spray cooling and laser irradiation for improved therapy of port wine stain, Laser Surg. Med. 43: 164-175, 2011.
  4. M. Milanič, I. Serša, B. Majaron, A spectrally composite reconstruction approach for improved resolution of pulsed photothermal temperature profiling in water-based tissues, Phys. Med. Biol. 54, 2829–2844, 2009.
  5. U. Ahčan, P. Zorman, D. Recek, S. Ralca, B. Majaron, Port wine stain treatment with a dual-wavelength Nd:YAG laser and cryogen spray cooling: a pilot study, Lasers Surg. Med. 44, 164-167, 2004.
  6. B. Majaron, L.O. Svaasand, G. Aguilar, J.S. Nelson, Intermittent cryogen spray cooling for optimal heat extraction during dermatologic laser treatment, Phys. Med. Biol. 47, 3275-3289, 2002.
  7. B. Majaron, S. M. Srinivas, H.-en L. Huang, J. S. Nelson, Deep coagulation of dermal collagen with repetitive Er:YAG laser irradiation, Lasers Surg. Med. 26, 215-222, 2000.
  8. B. Majaron, P. Plestenjak, M. Lukač, Thermo-mechanical laser ablation of soft biological tissue: modeling the micro explosions, Appl. Phys. B 69, 71-80, 1999.
  9. B. Majaron, D. Šušterčič, M. Lukač, U. Skalerič, N. Funduk, Heat diffusion and debris screening in Er:YAG laser ablation of hard biological tissues, Appl. Phys. B 66, 479-487, 1998.