A new computational thermal model of the whole human body: Applications to patient warming blankets

ABSTRACT

Numerical simulation methods have been applied to calculations of heat transfer within living tissue. Traditionally, those methods have been node-based when applied to a whole-body analysis. With the increased capacity of modern computational hardware and software, it is now possible to routinely solve a continuous thermal model of the human body based on the finite-element technique. Such a continuous thermal model is, for the first time, described and implemented. The model specifies material properties for the various body regions (head, torso, arms, hands, legs, feet) based on the tissue types and distribution found in those zones. Important thermal processes such as metabolism, blood perfusion, and respiration are also included. The computational scheme also allows for the implementation of sweating, shivering, vasoconstriction/vasodilation, and changes to the thermal environment. The model is solved in the context of a patient-warming situation during or following a medical operation. In these situations, patients are susceptible to hypothermia which has adverse health effects. To counteract the heat losses from the body, a convective warming blanket is used. Data obtained from a blanket/mannequin experiment provided convection information which was then applied to the computational model. Comparisons between the computational model and inner tissue and skin temperatures from the literature show close agreement and give confidence to the numerical results.

Acknowledgments

This research was supported by Smiths Medical.