This implementation of CVSim is the work of Catherine Dunn with support by Thomas Heldt and contributions from Brandon Pierquet and Ali Saeed. Previous implementations were written by Bob Sah (1983), George Moody (1985), Tim Davis (1989), Rama Mukkamala (2001), Thomas Heldt (2002), and by Eun Bo Shim and his students (2003). The circulatory model used in CVSim was created by Roger Mark, based on an analog model of JG Defares and colleagues. The CVSim model was elaborated by Thomas Heldt, Eun Bo Shim, Roger Kamm, and Roger Mark. Development of CVSim was funded by the National Aeronautics and Space Administration (NASA) through the NASA Cooperative Agreement NCC 9-58 with the National Space Biomedical Research Institute.