The Effect of Hematocrit on Photoelectric Plethysmogram

Abstract

In order to study the effect of hematocrit (Ht) on the photoelectric plethysmograms of fingers and toes, an experimental model study and a clinical study were carried out. Experimentally, it was found that the height of the plethysmograms increased when the values of Ht were lowered. In the clinical study, 3 groups of patients with different Ht values ranging from 27 to 55% were examined. A reverse relationship was found between the Ht value and pulse height of the plethysmogram. The physical effects of the blood flow and contents upon the plethysmograms were discussed. © 1980, Tohoku University Medical Press. All rights reserved.