THORACIC CAGE IMPEDANCE MEASUREMENTS. IMPEDANCE PLETHYSMOGRAPHIC DETERMINATION OF CARDIAC OUTPUT (AN INTERPRETIVE STUDY),
Abstract
The current flux distribution in the human thorax between band electrodes placed at the base of the neck and around the lower thorax, using 100 kc. excitation, was investigated to explain known correlations between the thorax electrical impedance waveforms and cardiac activity - particularly cardiac output. Measurements of the current densities around the band electrodes, equipotential surfaces constructed from both surface and interior potential measurements, externally observed directed flux impedance waveforms, and impedance properties of an approximate thorax model indicated that the major portion of electrode current flux passed through the lung tissues rather than through the blood volumes of the heart having lower resistivity. The impedance plethysmographic waveforms, obtained between the band electrodes, therefore appeared to monitor the right ventricular stroke volume as relflected by impedance changes in the pulmonary vascular bed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1964
- Accession Number
- AD0603053
Entities
People
- D. Witsoe
- Edwin Kinnen
- William Kubicek
Organizations
- University of Minnesota