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Rojas-Altamirano G, Vargas RO, Escandón JP, Mil-Martínez R, Rojas-Montero A. Calculation of Effective Thermal Conductivity for Human Skin Using the Fractal Monte Carlo Method. MICROMACHINES 2022; 13:mi13030424. [PMID: 35334716 PMCID: PMC8953946 DOI: 10.3390/mi13030424] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Revised: 03/05/2022] [Accepted: 03/06/2022] [Indexed: 02/05/2023]
Abstract
In this work, an effective thermal conductivity (ETC) for living tissues, which directly affects the energy transport process, is determined. The fractal scaling and Monte Carlo methods are used to describe the tissue as a porous medium, and blood is considered a Newtonian and non-Newtonian fluid for comparative and analytical purposes. The effect of the principal variables—such as fractal dimensions DT and Df, porosity, and the power-law index, n—on the temperature profiles as a function of time and tissue depth, for one- and three-layer tissues, besides temperature distribution, are presented. ETC was improved by considering high tissue porosity, low tortuosity, and shear-thinning fluids. In three-layer tissues with different porosities, perfusion with a non-Newtonian fluid contributes to the understanding of the heat transfer process in some parts of the human body.
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Affiliation(s)
- Guillermo Rojas-Altamirano
- Departamento de Termofluidos, Instituto Politécnico Nacional, SEPI-ESIME Azcapotzalco, Av. de las Granjas No. 682, Col. Santa Catarina, Alcaldía Azcapotzalco, Ciudad de México 02250, Mexico; (G.R.-A.); (J.P.E.); (A.R.-M.)
| | - René O. Vargas
- Departamento de Termofluidos, Instituto Politécnico Nacional, SEPI-ESIME Azcapotzalco, Av. de las Granjas No. 682, Col. Santa Catarina, Alcaldía Azcapotzalco, Ciudad de México 02250, Mexico; (G.R.-A.); (J.P.E.); (A.R.-M.)
- Correspondence: ; Tel.: +52-55-5729-6000 (ext. 64511)
| | - Juan P. Escandón
- Departamento de Termofluidos, Instituto Politécnico Nacional, SEPI-ESIME Azcapotzalco, Av. de las Granjas No. 682, Col. Santa Catarina, Alcaldía Azcapotzalco, Ciudad de México 02250, Mexico; (G.R.-A.); (J.P.E.); (A.R.-M.)
| | - Rubén Mil-Martínez
- Escuela Militar de Ingenieros, Universidad del Ejército y Fuerza Aérea, Av. Industria Militar No. 261, Col. Lomas de San Isidro, Naucalpan de Juárez 53960, Mexico;
| | - Alan Rojas-Montero
- Departamento de Termofluidos, Instituto Politécnico Nacional, SEPI-ESIME Azcapotzalco, Av. de las Granjas No. 682, Col. Santa Catarina, Alcaldía Azcapotzalco, Ciudad de México 02250, Mexico; (G.R.-A.); (J.P.E.); (A.R.-M.)
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Liu J, Chen X, Xu LX. New thermal wave aspects on burn evaluation of skin subjected to instantaneous heating. IEEE Trans Biomed Eng 1999; 46:420-8. [PMID: 10217880 DOI: 10.1109/10.752939] [Citation(s) in RCA: 200] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Comparative studies on the well-known Pennes' equation and the newly developed thermal wave model of bioheat transfer (TWMBT) were performed to investigate the wave like behaviors of bioheat transfer occurred in thermal injury of biological bodies. The one-dimensional TWMBT in a finite medium was solved using separation of variables and the analytical solution showed distinctive wave behaviors of bioheat transfer in skin subjected to instantaneous heating. The finite difference method was used to simulate and study practical problems involved in burn injuries in which skin was stratified as three layers with various thermal physical properties. Deviations between the TWMBT and the traditional Pennes' equation imply that, for high flux heating with extremely short duration (i.e., flash fire), the TWMBT which accounts for finite thermal wave propagation may provide realistic predictions on burn evaluation. A general heat flux criterion has been established to determine when the thermal wave propagation dominates the principal heat transfer process and the TWMBT can be used for tissue temperature prediction and burn evaluation. A preliminary interpretation on the mechanisms of the wave like behaviors of heat transfer in living tissues was conducted. The application of thermal wave theory can also be possibly extended to other medical problems which involve instantaneous heating or cooling.
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Affiliation(s)
- J Liu
- Thermal Engineering Department, Tsinghua University, Beijing, P.R.C.
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Liu J, Zhang X, Wang C, Lu W, Ren Z. Generalized time delay bioheat equation and preliminary analysis on its wave nature. ACTA ACUST UNITED AC 1997. [DOI: 10.1007/bf02882462] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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