The Abdominal Circulatory Pump
Figure 3
3-A Schematic diagram of the experimental set-up used to measure Vbs as the difference between changes in body volume and trunk volume (ΔVb-ΔVtr). ΔVb and ΔVtr are measured simultaneously by whole body plethysmography and Opto-electronic plethysmography (OEP), respectively. OEP is based on a motion analysis system which measures the 3D positions of 89 reflective markers positioned on body surface by a set of TV cameras, and computes the volume of the trunk by Gauss's Theorem. 3-B Marker positions on the anterior (left photograph) and posterior (right photograph) trunk surface. In the middle figure a diagram of the thoraco-abdominal surface triangulation is shown.