Abstract
(1) The instrumental aspects of apexcardiography were studied with particular emphasis on the significance of decay characteristics of recording equipments in relation to wave form.
(2) The time constant of broadly used Sanborn pulse wave attachments (#373 etc.) was different from unit to unit. And, most of them were not sufficiently long for recording such a low frequency phenomena as in systolic wave of apex-beat.
(3) The source of short time constant of commercial pick-ups would be due to an air leak within its housing.542 MASHIMO, ET AL. Jap. Heart J. November, 1966
(4) A consideration was made about the feasibility of apexcardiogram with short time constants as a reference tracing of phonocardiogram.
