ABSTRACT
Bioelectric tissue impedance measurements to determine or infer biological information have a long history dating back to before the turn of the century. The start of modern clinical applications of bioelectric impedance (BEI) measurements can be attributed in large part to the reports by Nyboer [1970]. BEI measurements are commonly used in apnea monitoring, especially for infants, and in the detection of venous thrombus. Many papers report the use of the BEI technique for peripheral blood flow, cardiac stroke volume, and body composition. Commercial equipment is available for these latter three applications, although the reliability, validity, and accuracy of these applications have been questioned and, therefore, have not received widespread acceptance in the medical community.
