Many pulse duplicators model only half the heart, commonly the left atrium and ventricle, in order to test the mitral and aortic valves.
[1][6] The circulatory system blood vessels are typically modeled using tubing.
A pulse duplicator is a wave propagation model if it physically replicates the circulatory system in a more anatomically correct manner.
[2] A pulse duplicator is filled with a fluid with a similar viscosity and specific gravity compared to blood.
One such blood analog is a mixture of water, glycerol, and a small amount of sodium chloride.