Numerical simulation for the management of steady and unsteady flows in the presence of mixing for biomedical applications

Abstract

Numerical simulation models can be a highly effective starting point for the optimal design of biomedical devices. This concept forms the underpinnings of the research to be reported in this thesis. Three unique medical device applications are considered, and numerical modeling and simulation is performed to enable a near approach to an optimal design. Furthermore, numerical models can also provide valuable guidelines for experimentation and product development. Each of the considered applications serves a therapeutic function. The common denominator to all of the applications is the major role played by fluid dynamics. For each of these applications, a model that conforms closely to the physical situation is formulated and subsequently implemented by numerical computation to yield outcomes of practical utility. The first of the applications was motivated by the reality that certain patients require frequent access to the vascular system. For example, drug infusion during chemotherapy and dialysis treatment requires such access. To facilitate these intrusions, infusion ports are implanted at suitable sites. The design of such ports must enable convenience in injecting and extracting fluid media. Furthermore, if blood is one of the media, the geometry of the port must be tailored to avoid hemolysis. Filtration is a major issue in the sanitary handling of biological fluids. The manufacture of such filtration media and other biomedical sterile fabrics makes use of very fine diameter fibers. The second major focus of this thesis is to provide a highly effective means for the production of the needed fibers. The manufacturing process which was majorly improved by the present innovations is the melt-blowing process.There are many situations in which biomedical fluids must be extracted from the human body. For example, spent tracer fluids used in angiographies become a possible source of kidney damage unless they are extracted. The final focus of the thesis research was to develop a highly effective numerical model whose application guides the design of suction catheters suitable to the existing biological conditions.