Dependence of the heating effect on tissue absorption coefficient during corneal reshaping using different UV lasers: A numerical study

Abdelhalim, Ibrahim; Hamdy, Omnia; Hassan, Aziza Ahmed; Elnaby, Salah Hassab

doi:10.1007/s13246-021-00971-x

Cited by 13 publications

(7 citation statements)

References 17 publications

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“…Besides these effects, juxtaposed tissues to the irradiated regions are closely exposed to increasing temperature values [ 177 ]. These features are less effective in consolidated tissues such as bone, and cartilage compared to the soft tissues [ 178 , 179 ]. Therefore, attention should be taken to carefully regulate irradiation dose and reduce side effects on the surrounding niche while hydrogel mechanical properties remain intact [ 180 ].…”

Section: Chemical and Non-chemical Cross-linking In Scaffold Synthesismentioning

confidence: 99%

Tissue engineering modalities in skeletal muscles: focus on angiogenesis and immunomodulation properties

et al. 2023

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Muscular diseases and injuries are challenging issues in human medicine, resulting in physical disability. The advent of tissue engineering approaches has paved the way for the restoration and regeneration of injured muscle tissues along with available conventional therapies. Despite recent advances in the fabrication, synthesis, and application of hydrogels in terms of muscle tissue, there is a long way to find appropriate hydrogel types in patients with congenital and/or acquired musculoskeletal injuries. Regarding specific muscular tissue microenvironments, the applied hydrogels should provide a suitable platform for the activation of endogenous reparative mechanisms and concurrently deliver transplanting cells and therapeutics into the injured sites. Here, we aimed to highlight recent advances in muscle tissue engineering with a focus on recent strategies related to the regulation of vascularization and immune system response at the site of injury.

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Section: Chemical and Non-chemical Cross-linking In Scaffold Synthesismentioning

confidence: 99%

Tissue engineering modalities in skeletal muscles: focus on angiogenesis and immunomodulation properties

et al. 2023

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“…However, for a focused ultrasound transducer the equation can be reduced to Eqn. (8). Focused ultrasound transducer can be visualized by means of Fig.…”

Section: Pressure Wave Modellingmentioning

confidence: 99%

“…In [7], a mathematical model based simulation is proposed to investigate induced corneal vibrations due to air-puff and its relationship to intra-ocular pressure and viscoelasticity of the cornea. Other mathematical models are proposed to study the heating effect of different wavelengths of UV lasers used in corneal ablation procedures as well [8]- [10]. Temperature rise calculation due to microwave radiation formed the first step towards modelling the thermal behavior of the human eye [11], [12].…”

Section: Introductionmentioning

confidence: 99%

Mathematical Modelling for Cornea Viscoelastic and Thermal Behavior

Ahmed

Salem

Al-Atabany³

2022

Preprint

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Corneal biomechanics is of great interest to researchers recently. Clinical findings relate them to corneal diseases and to outcomes of refractive surgery. To have a solid understanding of corneal diseases’ progression, it is important to understand corneal biomechanics. Also, they are essential for better explaining outcomes of refractive surgeries and their undesired consequences. There is a difficulty for studying corneal biomechanics in-vivo and multiple limitations arise for ex-vivo studies. Hence mathematical modelling is considered as a proper solution to overcome such obstacles. Mathematical modelling of cornea in-vivo allows studying corneal viscoelasticity with taking into consideration all boundary conditions existing in real in-vivo situation. In this paper, three mathematical models are used to simulate corneal viscoelasticity and thermal behavior in two different loading situations: constant and transient loading. Two models of the three are used for viscoelasticity simulation which are Kelvin-Voigt and standard linear solid models. Viscoelasticity simulation results show that standard linear solid model is efficient for describing the viscoelastic behavior of human cornea in both loading conditions. Results show also that the deformation amplitude obtained from standard linear solid model is more reasonable for corneal soft-tissue deformation with respect to corresponding clinical findings than that obtained from Kelvin-Voigt model. Also, temperature rise due to the ultrasound pressure push is calculated using bioheat transfer model for both the axial direction and as a 2D spatial map using the third model. Thermal behavior results estimated corneal temperature rise to be about 0.2°C, which conforms with FDA regulations for soft tissue safety.

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“…Diffuse optical tomography is a safe, non-invasive technology that employs a laser in the red-NIR region (600 to 900 nm) to probe biological tissues/organs and characterize their absorption and scattering properties [37][38][39][40]. These properties control the light propagation in the observed tissues and differ according to the applied wavelength [41][42][43].…”

Section: Introductionmentioning

confidence: 99%

Early cancer detection using the fluorescent Ashwagandha chitosan nanoparticles combined with near-infrared light diffusion characterization: in vitro study

et al. 2023

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Early cancer diagnosis through characterizing light propagation and nanotechnology increases the survival rate. The present research is aimed at evaluating the consequence of using natural nanoparticles in cancer therapy and diagnosis. Colon cancer cells were differentiated from the normal cells via investigating light diffusion combined with the fluorescence effect of the Ashwagandha chitosan nanoparticles (Ash C NPs). Ionic gelation technique synthesized the Ash C NPs. High-resolution transmission electron microscope, dynamic light scattering, and zeta potential characterized Ash C NPs. Fourier transform infrared spectroscopy analyzed Ash C NPs, chitosan, and Ashwagandha root water extract. Moreover, the MTT assay evaluated the cytotoxicity of Ash C NPs under the action of near-infrared light (NIR) irradiation. The MTT assay outcomes were statistically analyzed by Bonferroni post hoc multiple two-group comparisons using one-way variance analysis (ANOVA). Based on the Monte-Carlo simulation technique, the spatially resolved steady-state diffusely reflected light from the cancerous and healthy cells is acquired. The diffuse equation reconstructed the optical fluence rate using the finite element technique. The fluorescent effect of the nanoparticles was observed when the cells were irradiated with NIR. The MTT assay revealed a decrease in the cell viability under the action of Ash C NPs with and without laser irradiation. Colon cancer and normal cells were differentiated based on the optical characterization after laser irradiation. The light diffusion equation was successfully resolved for the fluence rate on cells’ surfaces showing different normal and cancer cells values. Ash C NPs appeared its fluorescent effect in the presence of NIR laser.

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Dependence of the heating effect on tissue absorption coefficient during corneal reshaping using different UV lasers: A numerical study

Cited by 13 publications

References 17 publications

Tissue engineering modalities in skeletal muscles: focus on angiogenesis and immunomodulation properties

Tissue engineering modalities in skeletal muscles: focus on angiogenesis and immunomodulation properties

Mathematical Modelling for Cornea Viscoelastic and Thermal Behavior

Early cancer detection using the fluorescent Ashwagandha chitosan nanoparticles combined with near-infrared light diffusion characterization: in vitro study

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