scholarly journals Finite Element Analysis (FEA) of Local Hyperthermia on Soft Tissue

2021 ◽  
Vol 2071 (1) ◽  
pp. 012012
Author(s):  
S Yahud ◽  
N F A Ibrahim

Abstract Finite Element Analysis (FEA) is a method for simulating a local hyperthermia (HT) effect on the soft tissue liver by exposing it to an external heat higher than normal core body temperature. Local HT treatments are most commonly used to treat cancer tissue smaller than 3 cm in size by using radiofrequency ablation (RFA) technique. The radiofrequency probe provides an intense external heat source within the target zone with temperatures exceeding 50 °C, but its maximum temperature should not approach 100 °C. In this paper, the main idea is to study the effect of tumor diameter size on the exposure time, thermal exposure intensity and applied voltage. There are five (5) different tumor diameter tissue sizes that would be treated: 1 cm, 1.5 cm, and 2 cm of tumor tissue diameter treated with a monopolar of plain electrode, and 2 cm, 2.5 cm, and 3 cm of tumor diameter tissue treated with 4-prong retractable antennas of an electrode. The findings showed that the exposure time is influenced by the tumor diameter tissue and the voltage applied, with the bigger tumor diameter tissue necessitating the longest time exposure with a high voltage. The temperature range of 50-100 °C has been given by all of the voltage supplied. Both electrodes provide thermal damage between 6-20 minutes, which is 6 – 18.5 minutes for a plain electrode with a voltage supply of 20-35 V applied to 1cm, 1.5cm and 2 cm of tumor diameter tissue, and 10.5 – 12.5 minutes for a 4-prongs electrode with a voltage supply of 22-45 V applied to 2 cm, 2.5 cm and 3 cm of tumor tissue.

Author(s):  
Hai Yao ◽  
Wei Yong Gu

A 3D finite element model for charged hydrated soft tissue containing charged/uncharged solutes was developed based on the multi-phasic mechano-electrochemical mixture theory [1–2]. This model was applied to analyze the mechanical, chemical and electrical signals within the human intervertebral disc under mechanical loading. The effects of tissue composition and material property on the physical signals and the transport of fluid, ions and nutrients were investigated. This study is important for understanding disc biomechanics, disc nutrition and disc mechanobiology.


2020 ◽  
Vol 6 ◽  
pp. 322-329
Author(s):  
Jian Wang ◽  
Huan Jin ◽  
Zhi Yang ◽  
Bin Zhao ◽  
Xiao Ma ◽  
...  

Author(s):  
Md Tauhidul Islam ◽  
Anuj Chaudhry ◽  
Ginu Unnikrishnan ◽  
J. N. Reddy ◽  
Raffaella Righetti

Cancerous tissues are known to possess different poroelastic properties with respect to normal tissues. Interstitial permeability is one of these properties, and it has been shown to be of diagnostic relevance for the detection of soft tissue cancers and for assessment of their treatment. In some cases, interstitial permeability of cancers has been reported to be lower than the surrounding tissue, while in other cases interstitial permeability of cancers has been reported to be higher than the surrounding tissue. We have previously reported an analytical model of a cylindrical tumor embedded in a more permeable background. In this paper, we present and analyze a poroelastic mathematical model of a tumor tissue in cylindrical coordinate system, where the permeability of the tumor tissue is assumed to be higher than the surrounding normal tissue. A full set of analytical expressions are obtained for radial displacement, strain, and fluid pressure under stress relaxation testing conditions. The results obtained with the proposed analytical model are compared with corresponding finite element analysis results for a broad range of mechanical parameters of the tumor. The results indicate that the proposed model is accurate and closely resembles the finite element analysis. The availability of this model and its solutions can be helpful for ultrasound elastography applications such as for extracting the mechanical parameters of the tumor and normal tissue and, in general, to study the impact of poroelastic material properties in the assessment of tumors.


2013 ◽  
Vol 446-447 ◽  
pp. 503-508
Author(s):  
Xiao Feng Ding ◽  
Hui Chang

This paper presents an investigation into the losses and thermal characteristics of induction motors operated from pulse width-modulated (PWM) voltage supply in comparison to that operated from sinusoidal voltage supply. It was concluded that due to the abundant harmonics in the PWM waveforms, significant losses are induced in the motor by the inverter supply. The temperature ascends correspondingly. Experiments were conducted with no load and with load conditions. The losses and thermal characteristics were calculated using finite element analysis (FEA) and validated by the experiments.


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