Article

Investigation on three-dimensional temperature field of human knee considering anatomical structure

Authors:
  • Wenzhou Medical University, Wenzhou, China
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Abstract

Inappropriate heat and mass transfer is an extremely important factor to cause rheumatics of human knee which however receives few attentions up to now. Understanding the thermal behaviors of pathological knee tissues can help diagnose its pathological status and find out the most efficient therapeutical way, which is hard to access otherwise. This paper is dedicated to develop a theoretical model for characterizing the three-dimensional temperature fields of human knee by taking its real anatomical structure into consideration. Based on the classical Pennes bioheat transfer equation, the temperature fields of normal knees and pathological ones under various thermal conditions were numerically simulated and compared, which would help better understand the disease mechanisms causing trouble for human knee. Meanwhile, a medical infrared image system was adopted to map the surface temperature of human knee which qualitatively verifies the theoretical prediction and its diagnostic value. Further, effects of heating from outside on the knee tissue and interventional hyperthermia based on vessel heating were also evaluated. Potential therapeutical strategies were suggested for the thermal rehabilitation of rheumatic knee in the near future.

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... However, experimental measurements of temperature profile in the human body present great difficulties because of its invasive nature, the limited positioning of sensors, the imprecision of the data obtained and ethical issues linked to in vivo experiments (Trobec et al., 2008). Yet, the studies investigating temperature behavior in living tissues (Trobec et al., 2008;Xiao et al.,2010;Silva, 2011;Trobec and Depolli, 2011;Narasimhan and Jha, 2012) have grown steadily since 1948 when Harry Pennes proposed the first model of bio-transfer heat that related the temperature of biological tissues to blood perfusion and the generation of metabolic heat based on his experiments (Pennes, 1948). This model is known as the Pennes bio-transfer heat equation. ...
... For the skin, there is a difference of 8.9% between the results. According to Xiao et al. (2010), the temperature of the skin in the condition of thermal neutrality is between 30.2 and 32.8 ° C. It does not show the temperature of the other tissues. This greater difference found between the temperatures in the skin is due to the different conditions of air temperature and convective coefficient adopted in the three studies: Trobec et al. (2008) considers the ambient temperature at 27 ° C and Xiao et al. (2010) ...
... According to Xiao et al. (2010), the temperature of the skin in the condition of thermal neutrality is between 30.2 and 32.8 ° C. It does not show the temperature of the other tissues. This greater difference found between the temperatures in the skin is due to the different conditions of air temperature and convective coefficient adopted in the three studies: Trobec et al. (2008) considers the ambient temperature at 27 ° C and Xiao et al. (2010) ...
... Theoretical studies of brain hypothermia have been attracted great attention because experimental methods are relatively difficult to perform. Many previous studies have modeled the heat transfer in the brain by using Pennes bioheat equation because of its simplicity, effectiveness, and ease of application; this equation has successfully predicted the temperature distributions in kidney cortexes [17], knees [18], canine prostates [19], feet [20], and brains [5e12]. Solving the Pennes bioheat equation is difficult because of its complicated form for the differential equation and the tissues. ...
... Solving the Pennes bioheat equation is difficult because of its complicated form for the differential equation and the tissues. Various numerical methods [5e12, 18,21e36], including finite difference method [5,6,8,9,21e24], finite volume method [10,18], finite element method [7,9,11,12,25,26], boundary element method [27e32], meshless method [33], control volume method [34] and numerical Green's approach [35], have been widely used to solve the Pennes bioheat equation. Among them, for solving the Pennes bioheat equation for the brain, finite difference method [5,6,8,9], finite volume method [10], and finite element method [7,9,11,12], have been used. ...
... Chua et al. used the Pennes bioheat equation to predict the temperature distribution within the human eye that is subjected to a laser source, and reported that the agreement between the model and experimental data up to 5% [24]. Xiao et al. developed by Pennes bioheat equation a heat transfer model for characterizing the three dimensional temperature fields of human knee, and they qualitatively validated the model by using a medical infrared image system to map the surface temperature of human knee [25]. Chen and Xu investigated the heat transfer in the kidney phantom during water-bath heating [26]. ...
... It is difficult to solve the bioheat equations because of its complicated forms of the differential equation and the tissues. Various numerical methods, including finite difference method [2,8,29], finite volume method [25], finite element method [30], boundary element method [31e33], meshless method [34], and numerical Green's approach [35], have been widely used to solve the Pennes bioheat equation. On the other hand, analytical solutions to the Pennes bioheat equation are also derived by applying the methods of Green's function [36e39], separation of variables [40,41], and Laplace transform [42,43]. ...
... However, the method taking the temperature distribution and temperature difference information of body surface as the basis for diagnosis of diseases has many limitations, because it is ignored that the internal thermal distribution of lesion in human body carries lots of valuable disease information, which is of great importance for the diagnosis of diseases [15][16][17][18]. At present, the medical imaging technologies being commonly used such as magnetic resonance imaging (MRI), X-CT imaging, ultrasonic imaging etc., can provide some related biochemical and pathologic information, nevertheless these technologies have a fundamental constraint, that is they can only display the shape changes of body tissue, but not reflect functional changes of body tissue [19,20]. When the structural lesions emerge in the human body, the qualitative changes of the patient's condition have taken place [21][22][23][24][25]. ...
... In order to mine the valuable 3-dimensional heat distribution data based on temperature distribution of body surface, many research groups have carried out in-depth studies and made a series of achievements [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. This present paper aims to acquire the q-r characteristic curve of the heat intensity varying with depth of tomography based on the temperature distribution characteristics of tumor in different stages. ...
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... The distribution of heat in the human knee was described by Xiao et al. [24]. Taking into account the anatomical structure of human knee, Xiao et al. developed a theoretical model for three-dimensional temperature Reumatologia 2018; 56/5 fields of the human knee. ...
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Hyperthermia is a method applied in the treatment of many diseases, including rheumatic diseases. There are relatively few reports concerning the role of that method in the treatment of these diseases, and most studies have not been randomised. Hyperthermia includes directed application of thermal energy. The aim of that therapy is to overcome the body's natural thermoregulation mechanism through application of external heat sources such as electromagnetic radiation of various frequencies, or ultrasound. Usually, temperatures are used within the 38.5-43° range. Hyperthermia can be applied as topical, regional, or systemic treatment (the latter is called hyperthermia of the whole body). In rheumatology, mainly the effect of hyperthermia on the immune system of the body is used. That effect depends on the type of hyperthermia and temperatures applied. Best documented are the effects of hyperthermia in fibromyalgia and ankylosing spondylitis.
... However, given the paucity of experimental data for comparison, it is not possible to assess the impact of this consideration on the found studies. Xiao et al. [26] performed numerical simulations to assess the contributions of temperature fields in normal and pathological knees on the effect of heating. The geometric model used for simulation considered only the skin, muscle, bone and blood vessels. ...
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Tissue heating is used for the treatment of health disorders. However, the benefits of this therapy depend heavily on the temperature reached in the tissues. Values outside the ideal range recommended for therapeutic effects may result in ineffective or tissue-damaging treatments. Thus, understanding the heat transfer process and knowing the temperature distribution in biological tissues are essential factors for this treatment to be applied safely and effectively. In this context, the numerical simulation becomes an interesting tool to understand the temperature field in the different tissues that make up the joint and, thus, to contribute to a better application of the thermal resources used in the clinical practice of physiotherapy. This study aimed to simulate the transient heat transfer in a canine knee joint during the application of a therapeutic heating feature and to investigate the effects of blood perfusion performed at a constant rate (A1 simulation) and as a function of tissue temperature distribution (A2 simulation). The heat diffusion equation was used to model the heat transfer phenomenon. The simulations were performed using the ANSYS-CFX® program. The results obtained from the simulations were compared with in vivo experimental data. The A1 simulation showed a maximum percentage difference of 25.6% compared to the experimental data. In contrast, the highest percentage difference found for the A2 simulation was 9.8%. In conclusion, the results suggest that simulation can be an important tool to evaluate the temperature behaviour of biological tissues during the application of thermal therapeutic resources.
... In order to obtain the thermal behaviors for the EED/skin system, the bio-heat transfer in human skin tissue is necessarily considered, which has been investigated in many articles [22][23][24][25][26][27]. Human skin can be divided into three layers: epidermis layer, dermis layer and fat layer from outside to inside, whose thermal parameters (e. g. conductivities and diffusivities) are totally different. ...
... Despite the many advantages of numerical simulations, it is known that the considerations included in computational problem solutions can strongly influence the results and generate an incorrect interpretation of the heat transfer process. In the studies found in the literature, boundary conditions and the adopted considerations may have no justification, and numerous simplifications may have been made (XIAO et al., 2011;XUE;LIU, 2013). In addition, the results from the simulations are rarely compared with actual data (experimental in vivo), which leaves doubt about the veracity of the simulated data. ...
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... For an actual hyperthermia or cryosurgery, various composite structures are always encountered. This poses an ever tough issue to compute the reality as could as possible [48]. Modeling such bioheat transfer problem relies on the precise quantification on the desired target (see example (Fig. 7E). ...
... In 1948, Pennes et al. established the well known Pennes bioheat transfer equation that is recognized as the most suitable one in all bioheat transfer models so far. Its typical form can be expressed as follows [6]: ...
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... Furthermore, in (35) authors analyzed temperature changes in young and elderly subjects during exercise and presented that both groups have similar capacity for heat production and that elderly subjects have a lower resting temperature and slower heat dissipation. Authors in (36) investigate the heat transfer based on the optical flow through a 3D temperature field of a human knee in order to prove diagnostic significance of thermal behavior in determining the pathological status, and propose several therapeutic strategies for the rheumatic knee. Moreover, evaluation of whole body thermal adaptation during physical exercise can help determine ideal conditions for physical activities (37). ...
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A two-dimensional mathematical model was developed to estimate the contributions of different mechanisms of brain cooling during cold-water near-drowning. Mechanisms include 1) conductive heat loss through tissue to the water at the head surface and in the upper airway and 2) circulatory cooling to aspirated water via the lung and via venous return from the scalp. The model accounts for changes in boundary conditions, blood circulation, respiratory ventilation of water, and head size. Results indicate that conductive heat loss through the skull surface or the upper airways is minimal, although a small child-sized head will conductively cool faster than a large adult-sized head. However, ventilation of cold water may provide substantial brain cooling through circulatory cooling. Although it seems that water breathing is required for rapid "whole" brain cooling, it is possible that conductive cooling may provide some advantage by cooling the brain cortex peripherally and the brain stem centrally via the upper airway.
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In non-invasive thermal diagnostics, accurate correlations between the thermal image on skin surface and interior human pathophysiology are often desired, which require general solutions for the bioheat equation. In this study, the Monte Carlo method was implemented to solve the transient three-dimensional bio-heat transfer problem with non-linear boundary conditions (simultaneously with convection, radiation and evaporation) and space-dependent thermal physiological parameters. Detailed computations indicated that the thermal states of biological bodies, reflecting physiological conditions, could be correlated to the temperature or heat flux mapping recorded at the skin surface. The effect of the skin emissivity and humidity, the convective heat transfer coefficient, the relative humidity and temperature of the surrounding air, the metabolic rate and blood perfusion rate in the tumor, and the tumor size and number on the sensitivity of thermography are comprehensively investigated. Moreover, several thermal criteria for disease diagnostic were proposed based on statistical principles. Implementations of this study for the clinical thermal diagnostics are discussed.
Basic Technology of Vascular Intervention
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F.J. Criado, Basic Technology of Vascular Intervention, Phoenix Science Press, Nanjing, 2003. in Chinese.
Physical Thermal Method and Application in SARS Medicine
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J. Liu, Physical Thermal Method and Application in SARS Medicine, Science Press, Beijing, 2004. in Chinese.
The effect of hyperthermia (42·5∘C) on zymosan-induced synovitis of the knee, British society for rheumatology 33
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