Fatigue and Fracture of Wire-Based Systems used in Biomedical ApplicationsThursday (29.09.2016) 09:30 - 09:45 Part of:
Strands, cables, coils and their constituent fine wires are critical in the design of numerous medical devices and tools used for a variety of medical treatments. Guide wires, catheters, pacemakers, stents, staples, Functional Electrical Stimulation (FES) systems, eyeglass frames, endodontic files and orthodontic braces can be comprised of wires with diameters ranging from 10s to 100s of micrometers. Reliability of these systems and their constituent wires is vital as part of either internal or external treatment modalities. Although the frequency of confirmed fractures in these systems is quite low, the criticality of these components necessitates a thorough understanding of the aspects controlling the fracture and fatigue behavior. Moreover, optimization of these devices requires characterization of the fatigue and fracture properties of its constituent wires. A review of the architecture in these wire-based systems and stress states experienced during testing is presented. Furthermore, fatigue testing methodologies, including existing standards where applicable, is discussed followed by an overview of the common materials systems used in these devices well as emerging materials currently under investigation. The effects of changes in material composition, microstructure, processing and test conditions on fracture and fatigue behavior of wire and cable systems used in biomedical applications are presented. The review concludes with recommendations for future work.