Microgravity effects on Heart Valves Behaviour: the HVBM experiment on ISS

Long term exposure to the microgravity environment induces substantial changes in the cardiovascular system, causing a partial opening of the heart valves. This feature, together with a higher calcium concentration in blood, generated by microgravity, is expected to provoke a faster heart valve calcification process: heart failure can be a direct dramatic consequence. This paper presents the rationale of an experiment devoted to investigating the influence of the microgravity environment on leaflets' motion and development of the calcification process in the aortic heart valve. Such innovative experiment is under the framework of HVBM project, a collaboration between biomedical, electronic and space engineering students at Politecnico of Milano and ISAE Supaero. The design of the compact bench test is presented as well, being compliant with ICE Cubes facilities requirements and with Biomedical European Standards, in order to assure the comparison with existing performance parameters for bioprosthesis. The experiment is being designed to autonomously operate, thanks to a microcontroller that will automatically set the inputs and store the monitored variables. Challenging constraints in terms of dimensions, resources and budgets are tackled: the paper presents the process used for the design and development parts, highlighting the critical passages and the innovative solutions adopted to build the bench test.