A PHYSIOLOGICAL IN-VITRO MODEL OF THE INFERIOR VENA-CAVA WITH A COMPUTER-CONTROLLED FLOW SYSTEM FOR TESTING OF INFERIOR VENA-CAVA FILTERS

RATIONALE AND OBJECTIVES. The authors develop a physiologic in vitro m odel of the inferior vena cava (IVC) for testing of filters. METHODS. The model is driven by a centrifugal pump. A computer-controlled elect romagnetic valve is used for generation of different flow patterns, Li mitation of the pressure increase in case of IVC occlusion is achieved by a bypass circuit. A glycerin solution is used for perfusion. Artif icial clots are made from polyacrylamide gel. Data acquisition include s continuous monitoring of flow and difference pressure over the filte r and video recording of the testing events. RESULTS. The model can ge nerate constant and pulsatile hows, The pressure increase can be limit ed to 70 mm Hg in case of occlusion. Calculation of the flow velocitie s in the IVC is possible. A classification of thrombus capturing is pr esented. The testing of most of the results are reproducible. CONCLUSI ONS. The in vitro model simulates the physiologic conditions in the IV C. It can be used for comparative testing of different filters and the evaluation of new filter designs.