Heat Transfer Model for Menorrhagia

Abstract

Thermal balloon ablation is a modern non surgical procedure for the treatment of menorrhagia. It works on the principle of ablating the endometrial layer beyond a point of
regeneration thereby reducing blood loss. Mathematical modelling of this procedure helps in improving accuracy of the treatment which reduces adverse affects of the procedure thereby making the procedure safer. Pennes bio-heat equation is used to calculate transient temperature in the uterine cavity. Thermal injury integral is used to calculate the irreversible thermal destruction of the uterine tissue. When thermal injury integral equals to or is greater than 1, the tissue is destroyed which prevents regeneration of the endometrium. The presented mathematical model is verified with the published experimental findings to check the validity of the model. The effect of overall convective heat transfer coefficient and balloon fluid temperature on tissue damage is studied. For an overall convective heat transfer coefficient above 2000Wm-2K-1, maximum depth of ablation at 87°C was 3.77mm. For
higher fluid temperature, depth of ablation is found to increase. At a fluid temperature of 93°C, depth of ablation is found to be 4.39mm for an overall convective heat transfer coefficient 1000Wm-2K-1. The temperature at the surface of endometrium is found to increase with the increase in fluid temperature and also with the increase in overall convective heat transfer coefficient. The obtained results are valid in the absence of any pathological
condition. In case of existing pathological conditions, the effects caused by them are also to be included. Thus, mathematical modelling involving convective heat losses is an effective tool to make thermal balloon procedure more accurate.