Non-Invasive Monitoring of Temperature in the Heart Hypo- and Hyperthermia with Cardiopulmonary Bypass

Abstract

Background. The implementation of the method of non-invasive control of heart temperature based on the model of heat exchange in the myocardium during extracorporeal circulation is considered. Objective. The purpose of the research is the use of numerical simulation methods in the MSC Sinda system to estimate the temperature gradient that is observed on the surface of the myocardium during hypo- and hyperthermia in the conditions of artificial circulation. Methods. To obtain the original data in the cardiopulmonary bypass loop temperature sensor system in arterial, venous, and cardioplegic lines is used. When assessing the temperature gradient applied of thermal diagnostics methods and analysis of thermograp in the infrared spectrum that allow getting data for the simulation of heat transfer process between the myocardium and coronary vessels in the MSC Sinda system. Results. As a result of numerical modeling 2D-model of heat exchange in the myocardium was proposed and the comparative analysis of thermal images of open heart with hypo- and hyperthermia with cardiopulmonary bypass was carried out. Carrying out non-invasive temperature measurement and simulation results of heat transfer on the surface of the myocardium allow more accurately adjust the speed of warming (hyperthermia) of venous blood in the heat exchanger. Conclusions. The simulation results allow supplementing the qualitative indications of system sensors for cardiopulmonary bypass. Application of thermal diagnostics methods and imaging analysis of thermograms for the monitoring of venous return temperature cardiopulmonary bypass circuit that allows you to adjust the flow of blood to the hollow veins with using venous occlusion line change with the clamp or a special device.