Key result
In vitro testing of prosthetic heart valves using different pulse duplicators revealed difficulties in comparing results due to varying operating conditions and system sensitivities.
In vitro testing of prosthetic heart valves highlights the difficulty of comparing fluidodynamic results across different pulse duplicator systems due to varying operating conditions.
In vitro prosthetic valve data require cautious cross-system interpretation; leaves open standardization of pulse duplicator conditions for reliable comparisons.
The Laboratory of Biomedical Engineering (of the National Health Institute, technical body of the Italian Health Service) performs in vitro testing of prosthetic heart valves for mechanical characteristics of materials, fatigue life, and fluidodynamic performance. Testing of materials is directed towards the physicomechanical characterization of the structural components of the valves, e.g. elasticity and resistance to stress of biological tissues and stents. Long-term fatigue life tests are conducted by means of systems which make valves beat at more than 1200 cycles/min. These tests are preceded and followed by geometrical characterization and by steady flow testing in order to obtain information about stenosis and leakage. Special attention is devoted to pulsatile flow testing which is performed on two pulse duplicators: the Dynatek system and the system developed by the University of Sheffield. The same valve was tested with these systems according to their different possible set-ups within the general requirements established by ISO-DIS 5840. This paper presents significant measurements, taking into account their dependence on the systems adopted. Results show (a) the difficulties in comparing test results because of different operating conditions, and (b) the systems' sensitivity with regards to some parameters which affect measurements under comparable set-up conditions (FDA Interlaboratory Comparison Testing Protocol).
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Daniele et al. (1992) studied Prosthetic heart valves (in vitro). In vitro testing systems (Dynatek vs. University of Sheffield) vs. Different operating conditions was evaluated on Fluidodynamic performance and comparability of measurements. In vitro testing of prosthetic heart valves using different pulse duplicators revealed difficulties in comparing results due to varying operating conditions and system sensitivities.
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