Accession Number : AD0439088

Title :   THORACIC CAGE IMPEDANCE MEASUREMENTS. IMPEDANCE PLETHYSMOGRAPHIC DETERMINATION OF CARDIAC OUTPUT (A COMPARATIVE STUDY),

Corporate Author : MINNESOTA UNIV MINNEAPOLIS

Personal Author(s) : Kinnen,Edwin ; Kubicek,William ; Patterson,R.

Report Date : MAR 1964

Pagination or Media Count : 12

Abstract : Two band electrodes of tinned copper braid shielding 1 cm. wide were placed around the neck and thorax 2 cm. below the xiphisternal joint and connected to an electrical bridge circuit excited at 100 kc. The recorded change of impedance over a cardiac cycle was related proportionally to a nominal ventricular stroke volume by the ratio of thorax volume to the average measured impedance. A value of cardiac output, determined from the product of this ventricular stroke volume and the pulse rate, was determined for various subject body types and used to compute the cardiac index and cardiac output per unit body mass. The data were representative of the data reported in the literature. The correlation of cardiac output values, determined from the impedance product, with oxygen consumption rates was found to be 0.962. Compared with results reported by other laboratories, where standard procedures are used for cardiac output determinations, the data compared favorably when a constant correction factor was added. (Author)

Descriptors :   (*THORAX, CARDIOVASCULAR SYSTEM), (*CARDIOVASCULAR SYSTEM, THROAT), (*THROAT, ELECTRICAL IMPEDANCE), IMPEDANCE BRIDGES, BLOOD VOLUME, ELECTRODES, EXPERIMENTAL DATA, OXYGEN CONSUMPTION, MEASUREMENT

Distribution Statement : APPROVED FOR PUBLIC RELEASE