STANDARDIZATION OF PLETHYSMOGRAPHY FOR CLINICAL EXAMINATION OF PERIPHERAL BLOOD CIRCULATION

In this section, experiments were performed in normal subjects in order to study whether several items of plethysmographic examination are useful or not for test a peripheral biood circulation, and gain control data in the normal subject.1. There were spontaneous variations in an amplitude as well as a base line of the plethysmogram at rest. In a grade of the spontaneous variations daily and individual differences were recognized.2. A crest time, a basic oscillation time, an amplitude of initial wave and its half decay time were measured on each wave of the plethysmogram. Since individual differences in the crest time and the half decay time were little, a comparison of these two element with a pathological wave form are regarded to be significant.3. A propagation time of pulse wave was represented by a time from the Q wave of electrocardiogram to a rising point of the plethysmogram. It was 0.244sec (0.219-0.272sec) for the third finger and 0.313sec (0.301-0.324sec) for the big toe.4. When an extremity under test was shifted passively from a heart level, there were specific patterns in variations of a base line and an amplitude of the plethysmogram for each position (elevated or lowered) 5. Whcn a hand clap or a mental arithmetic were applied to the subject, a base line of the plethysmogram moved to a direction of vasoconstriction.From these results, following items were selected as standard items of the plethysmographic examination. (1) Spontaneous variations in an amplitude and a base line of the plethysmogram. (2) A wave form of the plethysmogram. (3) A propagation time of pulse wave. (4) Changes in a base line and an amplitude of the plethysmogram when an extremity under test was raised or lowered from a heart position. (5) Vasomotor reflex.