Localized Environmental Stress Cracking Failure of Medical Devices
Luer systems are established and standardized connection systems within the medical field. They are usually found in syringes, infusion sets, tubing, catheters or three way stopcocks. Failure in any of these medical devices exposes patients to unnecessary risks, which can be avoided with the help of a prior investigation. One of the most critical threat is identified as Environmental stress cracking (ESC). It is defined as premature failure due to simultaneous influence of mechanical stress and an environmental fluid. In order to avoid unexpected failure of these components, a fundamental knowledge about fluid-polymer interactions has to be established. Just as important are areas of high local stress within the component. These are more prone for initiation of a crack which can ultimately lead to the failure of the product.
A popular approach for the investigation of critical areas of stress concentrations is the application of finite element method (FEM) simulation. The use of such methods allows for an in depth analysis regarding the distribution and level of stress. This is especially useful for the inspection of more complex geometries such as Luer connectors. Aim of our studies is the detection of critical areas to elucidate the interaction with different medical drugs or disinfection fluids and finally to reduce the risk of unexpected failure of components used in infusion therapies.