Loading...
Search for:
laser-therapy
0.006 seconds
Evaluation of heat conduction in a laser irradiated tooth with the three-phase-lag bio-heat transfer model
, Article Thermal Science and Engineering Progress ; Volume 7 , 2018 , Pages 203-212 ; 24519049 (ISSN) ; Nouri-Borujerdi, A ; Mohammadzadeh, A ; Najafi, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
In this study, a dental short pulse laser with a Gaussian beam profile was applied normally to the top surface of a mineral organ i.e. the human tooth for a root canal therapy. A numerical method of finite difference is adopted to solve the time-dependent heat transfer equation. The real boundary conditions of thermal insulation on the sharp segment of the root canal and periodic heat flux on the top boundary of the tooth were applied. The comparison of a three-phase-lag (TPL) bio-heat transfer model with other heat transfer studies has shown that this new bio-heat model (TPL) could accurately predict the thermal behaviour of a non-homogeneous structure such as the human tooth. It was...
Stress behaviour across human tooth by temperature gradient resulting of laser irradiation
, Article Journal of Mechanical Engineering and Sciences ; Volume 14, Issue 1 , 2020 , Pages 6218-6228 ; Nouri Borujerdi, A ; Najafi, M ; Sharif University of Technology
Universiti Malaysia Pahang
2020
Abstract
The authors report the simulation of temperature distribution and thermally induced stress in the premolar tooth under ND-YAG pulsed laser beam. The Three-Phase-Lag (TPL) non-Fourier model is proposed to describe the heat conduction in the human tooth with nonhomogeneous inner structures. A premolar tooth comprising enamel, dentin, and pulp with real shapes and thicknesses are considered and a numerical method of finite difference was adopted to solve the time-dependent TPL bio-heat transfer, strain and stress equations. The surface heating scheme is applied for simulation of laser therapy. The aim of this laser therapy is that the temperature of pulp reaches to 47oC. The results are...
Numerical Investigation of Non-Fourier Heat Conduction in Human Skin
, M.Sc. Thesis Sharif University of Technology ; Taghizade Manzari, Merdad (Supervisor) ; Sani Joushaghani, Mahdi (Supervisor)
Abstract
When classical Fourier law of heat conduction is not applicable due to finite speed of heat propagation in a medium, non-Fourier heat conduction is used. In non-Fourier heat conduction, heat transfer is studied considering finite speed of heat flux (thermal wave) or temperature gradient or both (dual phase lag). Biological tissues like skin are one of the materials which show non-Fourier behavior during usual heating processes. In this research heat transfer in human skin is modeled by Fourier, thermal wave and dual phase lag (DPL) models. The equations are solved using the finite difference method and the temperature distribution across the tissue is calculated. In thermal wave model,...
Intravenous laser wavelength radiation effect on LCAT, PON1, catalase, and FRAP in diabetic rats
, Article Lasers in Medical Science ; Volume 35, Issue 1 , 2020 , Pages 131-138 ; Mirmiranpour, H ; Sobhani, S. O ; Moazami Goudarzi, N ; Sharif University of Technology
Springer
2020
Abstract
The main purpose of this study is to evaluate the effect of intravenous irradiation of different low-level laser wavelengths on the activity of lecithin-cholesterol acyltransferase (LCAT), paraoxonase (PON1), catalase, and ferric reducing ability of plasma (FRAP) in diabetic rats. First, diabetes was induced in rats using streptozotocin (STZ). Enzymes’ activity was measured in the blood samples and compared before and after intravenous laser blood irradiation. We used four continuous-wave lasers—IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm), and Blue (λ = 450 nm)—to compare the wavelength’s effect on different enzymes’ activity. Laser power was fixed at 0.01 mW and laser energy was...
Thermal Relaxation Time Of Healthy and Cancerous Tissue In Pulsed Laser Using Monte Carlo Simulation
, M.Sc. Thesis Sharif University of Technology ; Amjadi, Ahmad (Supervisor)
Abstract
Thermal relaxation time is the time when maximum temperature of a particle get to 1/e of it’s initial value. The destruction of a tissue depends to this important parameter. This parameter has studied by Monte Carlo simulation of pulsed laser in to environment as healthy and cancerous tissue. The main goal of this method is providing proper temperature in a special area so that minimize thermal destruction around that area. In this thesis, temperature distribution of tissue that is caused by pulsed laser, has solved by new method;in this new method the pulse duration uses for Monte Carlo simulation. Also using the solution of radiation transfer equation by Discretes Ordinate Method, new...
Intravenous laser wavelength irradiation effect on interleukins: Il-1α, il-1β, IL6 in diabetic rats
, Article Laser Therapy ; Volume 28, Issue 4 , 2019 , Pages 267-273 ; 08985901 (ISSN) ; Mirmiranpor, H ; Khandani, S ; Sobhani, S. O ; Shafaee, Y ; Sharif University of Technology
Japan Medical Laser Laboratory
2019
Abstract
Background and aims: The main purpose of this investigation in Low-Level Laser Therapy (LLLT) on diabetic rats is laser wavelength effect on interleukins: IL-1α, IL-1β, IL6. Materials (Subjects) and Methods: At first, diabetes was induced in Wistar rats by streptozotocin (STZ) injection. Then, by intravenous laser therapy, the rats were irradiated by four continuous wave lasers: IR (λ = 808 nm), Red (λ = 638 nm), Green (λ = 532 nm) and Blue (λ = 450 nm) to compare the related laser wavelength effect on different interleukins. The inflammatory parameters were measured 2,6 and 24 hours after laser therapy from blood samples and plotted for different laser wavelengths. Results: The results show...