Effect of purification, dehydration, and coagulation processes on the optical parameters of biological tissues

AbstractLaser methods, such as laser-induced fluorescence diagnostics, photodynamic therapy (PDT), and hyperthermia, are finding increasing use in medicine. Irradiation can be performed both with and without contact on the tissue surface. In the case of contact irradiation, especially when laser radiation is introduced into biological tissue through an optical fiber, it is important to know the processes taking place at the irradiation fiber end. These processes affect diffusely reflected radiation which returns to the fiber. By analyzing backscattered radiation, we can evaluate the quality of the radiation procedure and the state of the fiber end. The objectives of this study were to develop a method and device for measuring backscattered radiation power and using this method, to determine the time and temperature ranges realized in PDT and hyperthermia.Light propagation is discussed in bent optical fibers. A technique is proposed for measuring laser radiation intensity in the optical fiber bend. Based on this technique, a system was developed for monitoring the laser radiation dose absorbed in biological tissues. We studied samples of bovine liver, muscle and brain tissues. Experiments were performed using a 675 nm, 100–2200 mW continuous wave semi-conductor laser. Laser radiation was delivered through a silica/polymer optical fiber. Data concerning the temperature and transmitted radiation intensity was acquired.Modeling of the light propagation in a bent optical fiber showed that the sensitivity of the method depends on the position of the photodetectors, but is independent of the loop number of the optical fiber. The results of experiments are presented using different types of biological tissues. We obtained the experimental dependencies of backward and transmitted radiation intensities and the temperature of the tissue surface in the irradiated region on the irradiation time measured with a flat-end fiber. The characteristic ranges of tissue heating caused by irradiation were determined for use in clinical practice.The optical parameters of biological tissues change with increasing temperature. This affects the intensity of transmitting radiation and diffuse radiation entering the fiber. The change in the backscattered radiation intensity greatly depend on the temperature of the irradiated area. The control of the irradiation of biological objects provides an efficient delivery of laser radiation to biological tissues and increases hyperthermia and PDT treatment effect.

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Automatic system for optical parameters measurements of biological tissues

Photonics Letters of Poland ◽

10.4302/plp.v10i3.846 ◽

2018 ◽

Vol 10 (3) ◽

pp. 91

Author(s):

Paulina Listewnik ◽

Adam Mazikowski

Keyword(s):

Skin Diseases ◽

Biomedical Optics ◽

Biological Tissues ◽

Optical Parameters ◽

Modular Construction ◽

Measurement Systems ◽

Fundamental Properties ◽

Tissue Phantoms ◽

Measurement And Analysis ◽

Homogeneous Tissue

In this paper a system allowing execution of automatic measurements of the optical parameters of scattering materials in a efficient and accurate manner is proposed and described. The system is designed especially for measurements of biological tissues including phantoms, which closely imitate optical characteristics of a real tissue. The system has modular construction and is based on ISEL system, luminance and color meter and a computer with worked out dedicated software and user interface. Performed measurements of scattering distribution characteristics for selected materials revealed good accuracy, confirmed by comparative measurements using well-known reference characteristics. Full Text: PDF ReferencesWróbel, M. S., Popov, A. P., Bykov, A. V., Kinnunen, M., Jedrzejewska-Szczerska, M., & Tuchin, V. V. (2015). Measurements of fundamental properties of homogeneous tissue phantoms. Journal of Biomedical Optics CrossRef Wróbel, M. S., Jedrzejewska-Szczerska, M., Galla, S., Piechowski, L., Sawczak, M., Popov, A. P., Cenian, A. (2015). Use of optical skin phantoms for preclinical evaluation of laser efficiency for skin lesion therapy. Journal of Biomedical Optics. CrossRef Jędrzejewska-Szczerska, M., Wróbel, M. S., Galla, S., Popov, A. P., Bykov, A. V., Tuchin, V. V., & Cenian, A. (2015). Investigation of photothermolysis therapy of human skin diseases using optical phantoms. In Proceedings of SPIE - The International Society for Optical Engineering. CrossRef Brown A. M., et al.: Optical material characterization through BSDF measurement and analysis, Proc. of SPIE, Vol. 7792, 2010 CrossRef 4-Axis Controller: iMC-S8. Operating Instruction. ISEL Germany AG, 2012. DirectLink Konica Minolta, Inc. (2005-2013). Chroma meter CS-200. Datasheet. DirectLink Malacara D.: Color Vision and Colorimetry; Theory and Applications, SPIE Press, 2002. DirectLink A. Mazikowski, M. Trojanowski: Measurements of Spectral Spatial Distribution of Scattering Materials for Rear Projection Screens used in Virtual Reality Systems, Metrology and Measurement Systems, 20 (3), pp. 443 - 452, 2013 CrossRef

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Iterative indirect methods for determination of optical parameters of biological tissues

10.1117/12.697319 ◽

2006 ◽

Author(s):

Maxim S. Zarembo ◽

Nickolai N. Golovin ◽

Yuri P. Meshalkin

Keyword(s):

Biological Tissues ◽

Optical Parameters ◽

Indirect Methods

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Noncontact measurement of thermal and optical parameters of biological tissues and materials using IR laser radiometry

Russian Journal of Physical Chemistry A ◽

10.1134/s0036024409080275 ◽

2009 ◽

Vol 83 (8) ◽

pp. 1405-1413 ◽

Cited By ~ 2

Author(s):

A. V. Kondyurin ◽

A. P. Sviridov ◽

M. V. Obrezkova ◽

V. V. Lunin

Keyword(s):

Biological Tissues ◽

Optical Parameters ◽

Noncontact Measurement ◽

Ir Laser

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Modeling the Near Infrared Light Propagation in Biological Tissues

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.713-715.686 ◽

2015 ◽

Vol 713-715 ◽

pp. 686-689

Author(s):

Yu Xiang Wu ◽

Min Fang Huang ◽

Tao Song ◽

Guo Dong Xu

Keyword(s):

Biological Tissue ◽

Light Propagation ◽

Near Infrared ◽

Structural Characteristics ◽

Biological Tissues ◽

Infrared Light ◽

Optical Parameters ◽

Near Infrared Light ◽

Photon Propagation ◽

Transmission And Distribution

The model of photon energy distribution in biological tissue has a very important significance in the diagnosis and treatment of biomedical area. The history and development of optical transmission and distribution in the biological tissue is outlined. The structural characteristics and optical properties of biological tissue are explained and discussed. To demonstrate the model of photon propagation in biological tissue, several methods about laser and biological tissue interaction of transmission theory are summarized and the physical meaning of the tissue optical parameters on is considered. On this basis, we simulated near infrared light distribution of the biological tissue with Monte Carlo methods and obtained meaningful results.

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