AN ELECTRICAL IMPEDANCE PLETHYSMOGRAPH

Abstract : An electrical impedance plethysmograph has been developed at the Naval Missile Center. This plethysmograph is extremely flexible and sensitive in that it can be adapted to the acquisition of impedance changes relative to vascular volumes and to obtain data on heart rate and rhythm, and respiratory cycle. Results obtained included indications that a trace could be made which would be directly related to the blood flow through a section of a limb. With this instrumentation, traces representing the impedance cycle before, during, and after vascular systolic occlusion in a limb were obtained. An indirect index of systolic pressures could also be derived. (Author)