The authors develop a physiologic in vitro model of the inferior vena cava (IVC) for testing of filters.
The model is driven by a centrifugal pump. A computer-controlled electromagnetic valve is used for generation of different flow patterns. Limitation of the pressure increase in case of IVC occlusion is achieved by a bypass circuit. A glycerin solution is used for perfusion. Artificial clots are made from polyacrylamide gel. Data acquisition includes continuous monitoring of flow and difference pressure over the filter and video recording of the testing events.
The model can generate constant and pulsatile flows. The pressure increase can be limited to 70 mm Hg in case of occlusion. Calculation of the flow velocities in the IVC is possible. A classification of thrombus capturing is presented. The testing of most of the results are reproducible.
The in vitro model simulates the physiologic conditions in the IVC. It can be used for comparative testing of different filters and the evaluation of new filter designs.
From the *Department of Diagnostic Radiology, Städtische Kliniken Dortmund; the †Society of Biomedical Research Dortmund; the‡Institute of Mechanical Engineering, Fachhochschule Dortmund; the§Max-Plank-Institute for Molecular Physiology Dortmund; and the ∥Computing Center, University of Dortmund, August Schmidt Strasse, Dortmund, Germany.
Supported by the Society of Biomedical Research Dortmund. A grant was given the Fachhochschule Dortmund, Dortmund, Federal Republic of Germany and the Bundesministerium für Bildung, Wissenschaft, Forschung und Technologie, Bonn, Germany.
Reprint requests: Horst Jaeger, MD, Department of Diagnostic Radiology, Städtische Kliniken Dortmund, Beurhausstrasse 40, D-44137 Dortmund, Germany.
Received February 20, 1997, and accepted for publication, after revision, May 5, 1997.