Effects of blood perfusion rate on the optimization of RF-capacitive hyperthermia

1998 ◽  
Vol 45 (9) ◽  
pp. 1182-1186 ◽  
Author(s):  
S. Fujita ◽  
M. Tamazawa ◽  
K. Kuroda
Keyword(s):  
Blood Perfusion ◽  
Perfusion Rate ◽  
Blood Perfusion Rate

Estimation of Tissue Blood Perfusion Rate from Diffusible Indicator Measurements: A Sensitivity Analysis

1980 ◽  
Vol 102 (3) ◽  
pp. 258-264 ◽  
Author(s):  
A. Shitzer ◽  
R. C. Eberhart ◽  
J. Eisenfeld
Keyword(s):  
Sensitivity Analysis ◽  
Material Balance ◽  
Blood Perfusion ◽  
Tissue Perfusion ◽  
Optimal Time ◽  
Perfusion Rate ◽  
Experimental Conditions ◽  
Rate Analysis ◽  
Sensor Position ◽  
Blood Perfusion Rate

Recording the washout of indicator (for example, heat, radio-labeled dissolved gas, etc.) transiently introduced into tissue allows the estimation of tissue blood perfusion rate. Analysis of the washout data requires a material balance which appropriately accounts for all transport mechanisms and sources and sinks of the given indicator. From that balance one may perform a sensitivity analysis which specifies the susceptibility of the perfusion estimate to experimental errors in any of the pertinent parameters and variables. The sensitivity analysis is based on the normalized partial derivatives of tissue indicator concentration with respect to the experimental variables. The results indicate that the estimation of the tissue blood perfusion rate is highly sensitive to errors in the concentration of the diffusible indicator which dominate, by two orders of magnitude or more, the errors attributed to other parameters. For typical experimental conditions, the errors in the perfusion estimate due to the various parameters are shown to vary considerably, according to the sensor position and time of measurement. Based on this type of analysis, one may specify optimal temporal and spatial domains for the parameter estimation in order to minimize error propagation. The optimal time domains are shown to differ from those used in typical indicator washout analyses for estimating tissue perfusion rate.

Thermography as a Means of Blood Perfusion Measurement

1979 ◽  
Vol 101 (4) ◽  
pp. 246-249 ◽  
Author(s):  
J. E. Francis ◽  
R. Roggli ◽  
T. J. Love ◽  
C. P. Robinson
Keyword(s):  
Blood Flow ◽  
Skin Temperature ◽  
Strain Gage ◽  
Infrared Camera ◽  
Blood Perfusion ◽  
The Body ◽  
Perfusion Rate ◽  
Perfusion Measurement ◽  
Blood Perfusion Rate ◽  
Human Forearm

The scanning infrared camera has been used to verify an analytical model relating blood perfusion rate to skin temperature. The blood perfusion rates were measured with both the mercury strain gage and the volume plethysmograph on the human forearm. Thermograms were taken of the forearm and temperature measured using an optical densitometer. Comparison of the volume plethysmograph with the strain gage, and the thermograms with the strain gage indicate thermography to be a useful means of measuring blood flow. Thermography has the advantages of being noninvasive and can be used to measure blood perfusion in parts of the body not easily monitored with occlusive techniques.

Effects of laser acupuncture on blood perfusion rate

2006 ◽  
Author(s):  
Xian-ju Wang ◽  
Chang-chun Zeng ◽  
Han-ping Liu ◽  
Song-hao Liu ◽  
Liang-gang Liu
Keyword(s):  
Blood Perfusion ◽  
Laser Acupuncture ◽  
Perfusion Rate ◽  
Blood Perfusion Rate

Thermal Pulse Decay Method for Simultaneous Measurement of Local Thermal Conductivity and Blood Perfusion: A Theoretical Analysis

1986 ◽  
Vol 108 (3) ◽  
pp. 208-214 ◽  
Author(s):  
H. Arkin ◽  
K. R. Holmes ◽  
M. M. Chen ◽  
W. G. Bottje
Keyword(s):  
Thermal Conductivity ◽  
Blood Flow ◽  
Theoretical Analysis ◽  
Simultaneous Measurement ◽  
Blood Perfusion ◽  
Perfusion Rate ◽  
Tissue Conductivity ◽  
Thermal Pulse ◽  
Measurement Protocol ◽  
Blood Perfusion Rate

Presented here is a theoretical analysis of the recently developed thermal pulse decay (TPD) method for a simultaneous measurement of local tissue conductivity and blood perfusion rate. The paper describes the theoretical model upon which the TPD method is based and details its capabilities and limitations. The theoretical aspects that affected the development of the measurement protocol are also discussed. The performance of the method is demonstrated with an experimental example which compares the measurements of local kidney blood perfusion rates made using the TPD method with the total renal blood flow obtained coincidentally using a blood flowmeter, in an anesthetized dog.

Prediction of skin burn injury. Part 2: Parametric and sensitivity analysis

2002 ◽  
Vol 216 (3) ◽  
pp. 171-183 ◽  
Author(s):  
E Y-K Ng ◽  
L T Chua
Keyword(s):  
Thermal Conductivity ◽  
Sensitivity Analysis ◽  
Burn Injury ◽  
Convective Heat Transfer Coefficient ◽  
Blood Perfusion ◽  
Tissue Temperature ◽  
Two Dimensional ◽  
Perfusion Rate ◽  
Injury Threshold ◽  
Blood Perfusion Rate

Part 2 of this paper presents an analysis of variance (ANOVA) for investigating the precedence of the various parameters, and the effects of varying these parameters, in assessment of burn injury resulting from the exposure of skin surface to heat sources. A one-dimensional model based on the finite difference method (FDM), as implemented in a spreadsheet software application, is applied to the assessment of burn injury. Henriques' theory of skin burns is used for determining the spatial and temporal extent of tissue damage. The ranks of the effects of various factors were obtained. It was found that the highest ranked factor is the initial tissue temperature followed by the thermal conductivity of the epidermal layer. The effect of blood perfusion rate is ranked much below the combinations of other factors. The results from the present numerical experiment agree well with the results obtained by Palla. Sensitivity analysis of the critical exposure levels was also carried out and results are discussed. In this study, the effects of the various parameters on injury threshold were investigated. Again, the results indicate that the four parameters: thermal conductivity of the epidermis and dermis, convective heat transfer coefficient and initial tissue temperature, have a pronounced influence on assessing the burn injury threshold. It was also found that fat thermal conductivity and blood perfusion rate have no obvious effect on injury threshold. A two-dimensional analysis was further conducted to determine the sensitivity of the predicted injury to the values of frequency factor, P, and apparent activation energy, Δ E, used in the models. Part 1 of this study details the development of the computer models based on the one- and two-dimensional bioheat equations.

A surface heat disturbance method for measuring local tissue blood perfusion rate

2000 ◽  
Vol 29 (1) ◽  
pp. 34-44 ◽  
Author(s):  
Jian-Shu Peng ◽  
Ya-Qin Xia ◽  
Tao Gao ◽  
Xun-Lan Lei ◽  
Shu-Ying Zhao
Keyword(s):  
Blood Perfusion ◽  
Surface Heat ◽  
Perfusion Rate ◽  
Local Tissue ◽  
Blood Perfusion Rate

scholarly journals Computational Modelling of Dual-Phase Lag Bioheat Process in Cooling of Cutaneous Tissue Exposed to High Heating for Burn Injury Prediction

2021 ◽  
Author(s):  
George Oguntala ◽  
Yim Fun Hu ◽  
Gbeminiyi Sobamowo
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Burn Injury ◽  
Blood Perfusion ◽  
Skin Tissue ◽  
Critical Parameters ◽  
Skin Burn ◽  
Perfusion Rate ◽  
Blood Perfusion Rate ◽  
Cutaneous Tissue

Abstract Heat transfer in biological systems is critical in analytic and therapeutic burn applications. Timely burn evaluation and appropriate clinical management are critical to ameliorate the treatment outcome of burn patients. To apply appropriate burn treatment, it is necessary to understand the thermal parameters of the skin. The paper aims to model the non-Fourier bioheat process in the human skin using a multi-domain trivariate spectral collocation method to determine skin burn injury with non-ideal properties of tissue, blood perfusion and metabolism. The skin tissue internal water evaporation during direct heating is considered. Parametric studies on the effects of skin tissue properties, initial temperature, blood perfusion rate and heat transfer parameters for the thermal response and exposure time of triple-layer cutaneous tissues are carried out. The study shows that the initial tissue temperature, the thermal conductivity of the epidermis and dermis, relaxation and thermalisation time and convective heat transfer coefficient are critical parameters necessary for skin burn injury baseline examination. The thermal conductivity and blood perfusion rate also exhibit negligible effects on the burn injury threshold of the cutaneous tissue. The present study is aimed to assist burn evaluation for reliable experimentation, design and optimisation of thermal therapy delivery.

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