This work represents the next step in the ongoing development of a system to noninvasively estimate blood perfusion using thermal methods. A combination thermocouple/thermopile sensor records heat flux and temperature measurements on the tissue of interest (in this case skin) for a given period of time. These data, in combination with other experimental parameters, are read into a computer program that compares them to a biothermal finite difference model of the system. The program uses an iterative process incorporating Gauss Minimization to adjust parameters in the biothermal model until the predicted system behavior satisfactorily approximates the real world data. The result is an estimation of blood perfusion in the tissue being measured, as well as an estimate of the thermal contact resistance between the probe and tissue. The system is tested on human forearms, canine legs during laparoscopic spay surgery, and on a canine medial saphenous fasciocutaneous free tissue flap model. Experimental measurements, especially those performed on the tissue flap model, show distinct correlation between blood perfusion and bioprobe output. This research demonstrates the accuracy of the biothermal model and the parameter estimation technique, as well as the usability of the system in a clinical setting. / Master of Science

This work focuses on the development of a system to noninvasively estimate blood perfusion using thermal methods. This is accomplished by the combination of a bioprobe, biothermal model, and parameter estimation techniques. The probe consists of a heat flux sensor and surface thermocouple placed in contact with tissue while the opposite side is cooled by jets of room temperature air. The biothermal model predicts the temperature and heat flux within tissue and probe based upon the input of blood perfusion and the thermal contact resistance between probe and tissue. Parameter estimation techniques are developed that use the model to simultaneously estimate blood perfusion and contact resistance based on experimental heat flux and/or temperature. A gradient based system minimizes a sum of squares error function based on either or both heat flux and temperature. This system is tested on human forearms and in controlled flow rate experiments using tissue phantoms. Blood perfusion estimates from the controlled experiments are positively correlated with experimental flow rate. Experimental measurements and statistical analysis show distinct variations in the heat flux signal and rises in perfusion estimates with increasing flow rate. This research validates the use of thermal and parameter estimation methods to develop a practical, noninvasive probe to clinically measure blood perfusion. / Master of Science

The following master’s thesis examines the use of biothermal energy released during the decomposition process of composting. The aim of this thesis is to explain the heat generation principles of composting, to summarize its consumption possibilities, and to design a suitable use of the source for the demands of a real building. First, the theoretical framework compares various options of the biomass utilization. It then describes the biochemical course of organic matter decomposition, and conceptualizes the term thermocompost as well as different methods of heat extraction. Subsequently, it lists ways of applying this technology in practice. Second, the empirical part uses the findings to propose a compost pile installation, and its connection to the current heating and hot water system in Ecocentre Karpaty in Nová Lhota, Hodonín. Due to the low-temperature nature of the source and the mode of usage of the building, it is recommended to accumulate the heat generated in the hot water storage tank. The preheating of potable water is considered as its primary benefit. In case of sufficiently high temperature of the thermocompost, the design also includes the possibility of preheating of heating water. In conclusion, the thesis evaluates the financial costs of the project and determines the financial savings. These have – due to the low frequency of the building usage and the consumption of hot water reach – relatively low values.