Pulsatile

Cardiovascular medical device durability with pulsatile loading

Durability of vascular stents is typically determined by exposing them to physiologically relevant diametric distension levels by means of hydrodynamic pulsatile loading (ASTM F2477-07). This testing occurs on a stent test specimen that has been deployed into a mock (elastically simulated) vessel. The typical duration of this test is 10 years of equivalent use (at 72 beats per minute), or at least 380 million 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:

• Coronary stents
• Peripheral stents
• Neural stents
• Endovascular grafts
• Percutaneous heart valves
• Pulmonary stents
• Endobronchial valves
• Drug eluting stents
• Bioabsorbable stents
• Biological or biologically derived constructs

Pulsatile flow in tissue/organ baths and for tissue engineering applications

Pulsatile pressure and flow are often used in cardiovascular tissue engineering bioreactor systems and tissue/organ baths.  Bose® 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 Bose 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.