Durabilité des dispositifs médicaux cardiovasculaires soumis à une charge pulsatile
La durabilité des stents cardiovasculaires est généralement déterminée en les exposant à des niveaux de distension diamétrale physiologiquement pertinents en appliquant une charge pulsatile hydrodynamique (ASTM F2477-07). L’essai se réalise sur un échantillon de stent déployé dans un vaisseau factice (à élasticité simulée). La durée typique de cet essai est de 10 ans d’utilisation équivalente (à 72 battements par minute), ou au minimum 380 millions de cycles.
Stent durability systems are used for both research and product development. As a research tool, SN curves are generated to relate the stress relationship to the number of cycles. For durability and what the industry calls a “test to success”, these systems are used to perform the 400M cycle test required by FDA. Commonly tested devices include:
- Stents coronaires
- Stents périphériques
- Stents neuronaux
- Greffons endovasculaires
- Valvules cardiaques percutanées
- Stents pulmonaires
- Valvules endobronchiques
- Stents à diffusion médicamenteuse
- Stents bioabsorbables
- Constructions biologiques ou d’origine biologique
Débit pulsatile dans des bains pour tissus/organes et pour des applications d’ingénierie tissulaire
Pulsatile pressure and flow are often used in cardiovascular tissue engineering bioreactor systems and tissue/organ baths. TA ElectroForce® systems are able to apply pulsatile flow and pressure waveforms using either standard software capabilities such as sinusoidal waveforms or by importing customer-provided waveforms such as heart output. Single and multi-specimen sample configurations are available with the ability to provide independent flow loops. Sensors that measure pressure, vessel outer diameter and flow rate are available with the TA ElectroForce systems to fully characterize sample properties such as vessel compliance. The same systems can be used to measure burst pressure by applying a pressure ramp to the samples at a customer-defined rate.