Theory and Applications of Heat Transfer in Humans

Book Preface

The story of this book started with a phone call to my parents. I was complaining how there was a need for a comprehensive book to introduce the great width and breadth of the field of bioheat transfer, something like the impressive two-volume collection of Avraham Shitzer and Robert C. Eberhart, Heat Transfer in Medicine and Biology, that was published in 1985. My dad suggested that, maybe, I should take on the endeavor of producing such a work. The next thing I knew, I was seeking help from John Wiley & Sons, asking whether they were interested in publishing such a work, and from all of my friends and colleagues, asking them if they were willing to help produce such a book.The response was amazing – everyone most enthusiastically supported the idea, and collectively, we, as a community, were on our way to try to cover the vast ground that the field of bioheat transfer has grown into over the last 40 or so years.

The basic idea was to produce a book that presented the fundamental physics and physiology related to the field of bioheat transfer, along with some of the recent applications, all in one place, in such a way as to enable and enrich both a beginner and an advanced reader. It would provide a basic framework that could be used to obtain “decent” estimates, and also present ways to further develop more complex methods, if needed, to obtain more accurate results. To this end, the book is arranged in three sections. The first section, Physics (Chapters 1–20), presents the fundamental mathematical framework that can be used as is or combined together forming more complex tools to determine in vivo heating; the second section, Physiology (Chapters 21–27), presents ideas and data that provide the basis for the physiological assumptions needed to develop successful mathematical tools, and, finally, the third section, Applications (chapters 28–36), presents a few recent examples of how the marriage of the first two sections are used to solve problems of today and tomorrow.

More specifically, under Physics, Chapters 1 and 2 present the fundamentals of bioheat transfer modeling based on conservation of mass, momentum, and energy (i.e., first principles). The presented material is such that it can be used as is, or made more complex or simplified to build custom models for one’s own applications and desired accuracy. Chapter 3 discusses the role of various blood vessels in transporting thermal energy and affecting temperature distribution, in order to help develop application-specific thermal models. Chapter 4 discusses how a physiologically realistic blood-vessel network may be generated to gain a better understanding of the thermal nature of the vascular bed. Chapter 5 discusses how whole-body models of humans can be built and used to investigate the effect of clothing on humans. Chapter 6 presents physical and computational models of the human cardiovascular system. Chapter 7 discusses lumped-parameter-based computational models of the human respiratory system.The models presented in Chapters 6 and 7 may be combined with the bioheat models presented in Chapters 1 and 2 to build more complex simulation models to better understand human physiology. Chapter 8 presents various techniques of inverse heat transfer that may be used to determine parameters of computational models for biomedical applications. Chapters 9–12 present techniques to determine
the source-term distribution (or energy density) in various applications. Source-term distribution is needed to determine resultant in vivo temperature rise. Chapter 9 presents ways to quantify the source-term distribution due to the propagation of light in tissue. Chapter 10 presents ways to quantify the source-term distribution due to the propagation of ultrasound in tissue. Chapters 11 and 12 present ways to quantify the source-term distribution due to electromagnetic field propagation in tissues as experienced in magnetic resonance imaging (MRI) and other applications without and with “very high conductivity” material present in the body, respectively. Chapter 13 presents methods for fast computation and for evaluation of the computational performance. Chapters 14–16 present methods of thermometry using conventional methods, MRI, and ultrasound, respectively. Chapters 17–19 present methods for measuring thermal, optical, and dielectric properties of tissue, respectively. Chapter 20 presents methods of calorimetry for micro- and nanoscale biomedical applications.

Under “Physiology,” Chapter 21 presents cardiovascular and metabolic response to various thermal stimuli. Chapter 22 presents the role of morphological and physiological considerations in the modeling of human heat loss, mainly sweating. Chapter 23 presents changes in thermoregulatory response due to radiofrequency heating. Chapter 24, briefly, describes the clinical management of skin burns. It is hoped that presenting brief description of the current clinical-management methods in this book will prompt development of more effective ways to address clinical needs in the future. Chapter 25 describes thermoregulatory responses to toxic agents. Chapters 26 and 27 present methods for characterizing thermal damage due to “high” and “low” temperatures, respectively.

Under “Applications,” Chapter 28 presents the use of bioheat transfer models developed in Chapter 1 and techniques for determining the source term due to the electromagnetic field distribution inMRI developed in Chapter 11 in predicting heating during MRI. Chapter 29 presents uses of nanoparticles in cancer treatment. Chapter 30 presents how to use models of the blood-vessel network in planning hyperthermic and cryothermic treatments. Chapter 31 describes progress in thermal-imaging-assisted cryosurgery in cancer treatment and pain management. Chapter 32 presents methods for determining the role of blood flow onMRI-induced heating near stents. Chapter 33 presents ways to assess the damage associated with skin burns using mathematical models. Chapter 34 presents surface and endovascular cooling methods, models, and measurements. Chapter 35 presents methods for assessing the effects of wind chill on body temperature. The last chapter, Chapter 36, presents uses of the principles of bioheat transfer in determining time of death.