Physiological mathematical modeling

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Due to exposure to micro-gravity, astronauts are at an elevated risk for developing renal (kidney) stones upon return to gravity. N&R Engineering is currently assisting NASA with probabilistic analyses of implemented deterministic models to determine the rate of calcium oxalate stone formation in the human kidney. A specialty deterministic code is being developed to simulate the physics of stone growth and passage through a single nephron (shown in yellow). There are two types of nephron that serve as the basic processing units of the kidney. These differ both in morphology and function; the average person has between 1 to 2 million nephrons of mixed type per kidney. The methodology being developed has the capacity to include gravity, drag, and other relevant coupled physicochemical-hydrodynamic phenomena which affect the formation and growth of calcium oxalate stones. In particular, the concentration profiles of dissolved species, such as calcium and oxalate, as well as changes in velocity profile, may be specified along the length of a nephron to calculate stone growth under specified conditions. The Probability Manager of PRODAF is then used to perform probabilistic systems analyses on a set of representative nephrons to assess sensitivity to various system parameters. The system engineering and composite materials background of the N&R Engineering staff provides a versatile skill-set with which to approach the study of homeostatic control mechanisms such as those employed by the human body to regulate the activities of cells, tissues, and organs. Employing a diverse and flexible knowledge and skills base, N&R is merging proven engineering techniques with cutting-edge quantititive biological modeling to solve medical problems relevant to the aerospace industry.