AN IMPEDANCE RESPIROMETER
Abstract
When a low-intensity, HF (20-60 kc) carrier signal is applied to a human subject between biaxillary electrodes, a change in impedance can be measured between the electrodes. This change in impedance closely parallels the simultaneous changes in the volume of respired air. The design and circuitry of an impedance respirometer are presented. Simultaneous tracings from this respirometer and a wedge spirometer were recorded from ten subjects during quiet sitting, standing, walking, and running in place through the physiological range of respiratory rate (8-40 breaths/min) and volume (1/2-4 liters). The output of the impedance respirometer correlated well with the output of the wedge spirometer in the quiet, seated subject. The problems of electrode configuration, body type, and electrode artifact are discussed. This system is a reliable and unencumbering method of monitor-respiratory rate and, potentially, respiratory volume. However, its use is severely limited by base line shifts and motion artifact due to changes in electrode impedance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1963
- Accession Number
- AD0411451
Entities
People
- Adolf R. Marko
- George W. Barnard
- Kenneth E. Robins
- Michael Mccally
Organizations
- Air Force Research Laboratory