Charles Samuel Peskin (born April 15, 1946) is an American mathematician known for his work in the mathematical modeling of blood flow in the heart. Such calculations are useful in the design of artificial heart valves. From this work has emerged an original computational method for fluid-structure interaction that is now called the “immersed boundary method". The immersed boundary method allows the coupling between deformable immersed structures and fluid flows to be handled in a computationally tractable way. With his students and colleagues, Peskin also has worked on mathematical models of such systems as the inner ear, arterial pulse, blood clotting, congenital heart disease, light adaptation in the retina, control of ovulation number, control of plasmid replication, molecular dynamics