A DIRECT CURRENT DIELECTROGRAPH FOR RECORDING THE MOVEMENTS OF THE HEART

Abstract

A direct current amplifier for recording capacitance changes is described. Its application to the study of the activity of the heart is indicated by records obtained on normal subjects and cardiac cases. The theory of the circuit for simple systems is presented. In limiting cases, capacitance changes are shown to be proportional to volume changes; voltage varying inversely as capacitance. Records obtained are, however, treated only qualitatively. They are found to be reproducible for a given subject, and the cycles are found to have quite regular features.