Abstract: Processes, algorithms and techniques are disclosed for detecting the presence of a source of at least one of heat, mass, momentum, energy, electrical field, and species in a system, such as, for identifying the presence of a heat source and its 3D location within a body part, and also to identify absence of a heat source within the body part. Multi-view thermal images are obtained of the body part and thermal and spatial information in different views are obtained. Iterative algorithms are developed to determine the presence of a heat source in the body part by employing the Physics-Informed Neural Network analyzer. Methods of generating a spatial-point-cloud and thermal-spatial-point-cloud are disclosed.