Venous occlusion plethysmography

Method for determining the pressure-dependent venous capacity and the maximum outflow volume of the leg (outflow plethysmography) at different dynamic pressure levels. The measurement is usually carried out via strain-gauge plethysmography. The calf and ankle or the largest circumference of the forearm and wrist serve as the measuring point. Further plethysmographic methods:

• Water plethysmography (volume measurements via water displacement)
• impedance plethysmography (measurement of voltage differences)
• Videooplethysmography (not very common; high specificity, sensitivity and accuracy in acute ileofemoral venous thrombosis; the blood volume of the calf and the speed of emptying are reduced)
• Air plethysmography (detection of changes in air pressure in a cuff or airtight measuring chamber enclosing the limb
• Gravidmetric plethysmography: detection of the weight changes of the extremity
• Optical vein occlusion plethysmography: detection of the reflection changes under a sensor
• Microwave plethysmography: detection of tissue absorption in the microwave range of the electromagnetic spectrum