Shlykov V. The Information technology of non-invasive control the temperature of the human heart in conditions of controlled cooling and warming during cardiopulmonary bypass

In the dissertation the methodical and technical means of technology of non-invasive control and effective regulation of heart and body temperature in conditions of cardiopulmonary bypass are substantiated and developed. For the first time, the technology of non-invasive control of heart's temperature in conditions of cardiopulmonary bypass circulation has been proposed, which allows to improve the existing clinical methods of intraoperative protection of the heart and brain on the basis of the introduction of technique for infrared thermography in the cardiac surgery in at the temperature range from + 4°C to + 38°C. The application of mathematical models for thermal processes in the heart for hypothermia and hyperthermia allows theoretically investigating the distribution of deep and superficial temperatures in the tissues, as well as significantly increasing the reliability of the clinical interpretation of the results for the application of the technology of non-invasive temperature control. The developed thermal models of heat exchange between the coronary vessels and the myocardium allow estimating the temperature gradient on the surface of the heart, to calculate the temperature coefficient of cooling and warming of the myocardium, the temperature conductivity of the tissues that makes possible to determine the presence of ischemic regions on the surface of the myocardium. The method of digital processing of thermograms with the filtration of the visual backgrounds of the myocardium in the process of hypothermia and hyperthermia allows according for data of the temperature distribution to find on the thermogram the branches of coronary vessels and their distal regions. The obtained data allow determining the degree of coronary obstruction and the degree of narrowing of the coronary arteries, which reduces the probability of ischemic complications after surgery for the open heart. Studies that conducted at the clinical base of the Amosov National Institute of Cardiovascular Surgery NAN Ukraine show high efficiency and sufficient accuracy of non-invasive methods of infrared thermography, as the technical means for detecting pathology and assessing the functional state of the cardiovascular system in case blood flow disorders.