A Modular Mock Circulation for Hydromechanical Studies on Valves, Stenoses, Vascular Grafts and Cardiac Assist Devices

Abstract

Devices for hydrodynamic simulation are required in a variety of studies such as device evaluation, cardiovascular modeling and for student training. Most studies today use different, incompatible circuits, which must be redesigned for every new application. To obtain a universal apparatus, a unitized system with standard connectors was developed. Three types of connectors were selected: 1″ flange connectors, ½″ tubing connectors and Luer-connectors with a 2 mm lumen. The complete system consists of reservoirs, throttles, valve holders, adapters for Doppler ultrasound probes, and converters to link these basic diameters. The apparatus can be driven by membrane, centrifugal and geared pumps. The system has successfully been used in echocardiographic studies of stenosis and valvular insufficiency, for pulse propagation in vascular grafts, and to test the hydraulic performance of cardiac assist devices. Flow rates between 0.1 and 30 l/min and pressure gradients up to 250 mmHg were achieved. In practical use, the system can be adapted to suit various investigations, with minimal expense. Standardization of the parts and connectors results in simple documentation and good reproducibility.