The temperature dependent thermal properties of ex vivo porcine liver tissue heated from 20°C to 90°C

2012 ◽  
Vol 131 (4) ◽  
pp. 3364-3364 ◽  
Author(s):  
Min Joo Choi ◽  
Sitaramanjaneya Reddy Guntur ◽  
Kang IL Lee ◽  
Dong Guk Paeng ◽  
Andrew Coleman
Keyword(s):  
Thermal Properties ◽  
Liver Tissue ◽  
Ex Vivo ◽  
Temperature Dependent ◽  
Porcine Liver

Temperature-Dependent Thermal Properties of ex Vivo Liver Undergoing Thermal Ablation

2013 ◽  
Vol 39 (10) ◽  
pp. 1771-1784 ◽  
Author(s):  
Sitaramanjaneya Reddy Guntur ◽  
Kang Il Lee ◽  
Dong-Guk Paeng ◽  
Andrew John Coleman ◽  
Min Joo Choi
Keyword(s):  
Thermal Properties ◽  
Thermal Ablation ◽  
Ex Vivo ◽  
Temperature Dependent

Temperature dependence of thermal properties of ex vivo liver tissue up to ablative temperatures

2019 ◽  
Vol 64 (10) ◽  
pp. 105016 ◽  
Author(s):  
V Lopresto ◽  
A Argentieri ◽  
R Pinto ◽  
M Cavagnaro
Keyword(s):  
Thermal Properties ◽  
Temperature Dependence ◽  
Liver Tissue ◽  
Ex Vivo

scholarly journals Investigation of radiofrequency ablation process in liver tissue by finite element modeling and experiment

Medicina ◽  
2007 ◽  
Vol 43 (4) ◽  
pp. 310 ◽  
Author(s):  
Rimantas Barauskas ◽  
Antanas Gulbinas ◽  
Giedrius Barauskas
Keyword(s):  
Finite Element ◽  
Radiofrequency Ablation ◽  
Mathematical Models ◽  
Thermal Effect ◽  
Electric Current ◽  
Liver Tissue ◽  
Ex Vivo ◽  
Biological Tissues ◽  
Tissue Destruction ◽  
Porcine Liver

Background. The character of ablation processes with high-frequency electrical current is similar in most biological tissues; however, quantitative characteristics are very different. Consequently, mathematical models of the process have a lot of specific aspects. In this study, we developed mathematical model of radiofrequency ablation in liver tissues with experimental validation of model in ex vivo porcine liver. Methods. The finite element nonlinear computational model for the simulation of the radiofrequency ablation processes and taking into account coupled electrical and thermal phenomena has been developed. The radiofrequency electric current processes are dominated by the active electric conductivity. The heat generation in biological tissues is determined by the electric current density. Simultaneously, the conductivity of the tissue is nonlinearly dependent upon the temperature of the tissue. The model has been implemented in COMSOL Multiphysics computational environment. Tests on physical characteristics of the thermal effect in ex vivo liver tissue have been performed and results compared. Results. Two oval-shaped zones of total and relative tissue destruction were highlighted. The principal distribution of the thermal effect is congruous with the theoretical model; however, the discrepancy of temperatures in experimental and theoretical models increases distally from active perfusion electrode. Conclusions. Distribution of the thermal effect is congruous in the theoretical and experimental model; however, discrepancies of temperatures imply certain inadequacies of the mathematical models. Differences of computed and actual temperatures should be regarded predicting tissue ablation in clinical setting.

Dielectric Properties of Ex Vivo Porcine Liver Tissue Characterized at Frequencies Between 5 and 500 kHz When Heated at Different Rates

2018 ◽  
Vol 65 (11) ◽  
pp. 2560-2568 ◽  
Author(s):  
Douglas Deas Yero ◽  
Fidel Gilart Gonzalez ◽  
Dirk Van Troyen ◽  
Guy A. E. Vandenbosch
Keyword(s):  
Dielectric Properties ◽  
Liver Tissue ◽  
Ex Vivo ◽  
Porcine Liver

scholarly journals Frequency and average gray-level information for thermal ablation status in ultrasound B-Mode sequences

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Jens Ziegle ◽  
Alfredo Illanes ◽  
Axel Boese ◽  
Michael Friebe
Keyword(s):  
Thermal Ablation ◽  
Ex Vivo ◽  
Cell Damage ◽  
Potential Temperature ◽  
Image Sequences ◽  
Target Tissue ◽  
Gray Level ◽  
Porcine Liver ◽  
Time Frequency ◽  
Average Gray Level

AbstractDuring thermal ablation in a target tissue the information about temperature is crucial for decision making of successful therapy. An observable temporal and spatial temperature propagation would give a visual feedback of irreversible cell damage of the target tissue. Potential temperature features in ultrasound (US) B-Mode image sequences during radiofrequency (RF) ablation in ex-vivo porcine liver were found and analysed. These features could help to detect the transition between reversible and irreversible damage of the ablated target tissue. Experimental RF ablations of ex-vivo porcine liver were imaged with US B-Mode imaging and image sequences were recorded. Temperature was simultaneously measured within the liver tissue around a bipolar RF needle electrode. In the B-Mode images, regions of interest (ROIs) around the centre of the measurement spots were analysed in post-processing using average gray-level (AVGL) compared against temperature. The pole of maximum energy level in the time-frequency domain of the AVGL changes was investigated in relation to the measured temperatures. Frequency shifts of the pole were observed which could be related to transitions between the states of tissue damage.

Analysis of Tempering and Rehardening for Grinding of Hardened Steels

1991 ◽  
Vol 113 (4) ◽  
pp. 388-394 ◽  
Author(s):  
O. B. Fedoseev ◽  
S. Malkin
Keyword(s):  
Thermal Properties ◽  
Heat Source ◽  
Hardened Steel ◽  
Temperature History ◽  
Hardness Distribution ◽  
Temperature Dependent ◽  
Thermally Activated ◽  
Reaction Equations ◽  
Rate Controlling Step ◽  
Good Agreement

An analysis is presented to predict the hardness distribution in the subsurface of hardened steel due to tempering and rehardening associated with high temperatures generated in grinding. The grinding temperatures are modeled with a triangular heat source at the grinding zone and temperature-dependent thermal properties. The temperature history, including the effect of multiple grinding passes, is coupled with thermally activated reaction equations for tempering and for reaustenitization which is the rate controlling step in rehardening. Experimental results from the literature are found to be in good agreement with the analytical predictions.

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