What is "ballistocardiograph"

n. An instrument which measures ballistic forces on the heart, producing a graphical representation of repetitive motions of the human body arising from the sudden ejection of blood into the great vessels with each heart beat.

n. a medical instrument that measures the mechanical force of cardiac contractions and the amount of blood passing through the heart during a specified period by measuring the recoil of the body as blood is pumped from the ventricles [syn: cardiograph]