This is an example of the first artificial heart valve developed by pioneering heart surgeon Dr. Charles Hufnagel. The interior ball was made of hollow methylmethacrylate. The ball made so much noise the wearer could be heard walking down the hall. Hufnagel later replaced the noisy ball with ones coated with silicone. They proved to be considerably quieter.

Hufnagel, invented the plastic implantable heart valve in 1947. The ridged valve was first implanted in a human in 1952 at Georgetown University Hospital in Washington, D.C. Hufnagel experimented with various materials but settled on polymethyl methacrylate, a hard, clear plastic more popularly known by the trade name of Plexiglas or Lucite.

*Historic information courtesy of the Smithsonian