Abstract
The author constructed a Ballistocardiograph, which consists of condensermicrophone, chair, balance and electric magnifying apparatus. When a patient sits on the chair, moving of human body by his circulation is received by the balance, and mechanical change of balance is converted to change of electric capacity by condensermicrophone which is magnified and recorded. The curve which is recorded by this apparatus, like that of Mr. I. Starr, consists of three main waves, e.g. I, J, K wave. Ballistocardiogram was compared with electrocardiogram and electrophonogram, and it was corroborated that I-wave was caused by the repercussion of human body when heart ejected the blood.
