Intravascular and Intracardiac Pressure Recording in Man: Electrical Apparatus Compared with the Hamilton Manometer.

Abstract

The Clark Pressure Capsule, an electrical pressure pickup device, has been found satisfactory for recording blood pressures from the right heart, pulmonary artery, systemic arteries, pleural and mask pressures in man, when used with a suitable amplification and recording device. The tracings recorded with this apparatus compare closely with those obtained simultaneously with a Hamilton manometer system. Slight pressure movement on the diaphragm in the Clark pressure capsule alters the magnetic reluctance, creating an electrical imbalance in a previously balanced bridge circuit. The electrical imbalance is amplified and a resulting galvanometer deflection photographed. Aerotronics Incorporated, Cam-den, Ohio, have been licensed to manufacture the Clark pressure capsule. Consolidated Engineering Corporation, Pasadena, California, manufactured the electrical amplifying and recording parts used, namely: (1) Bridge, balance type 3-103B, (2) Amplifier, 4 channel type 1-106, (3) Oscillator, carrier type 2-104B, and (4) Recording camera, oscillograph recording type 5-101 A.