Refining early stage interventional composite catheter design

The development paths of interventional medical devices are long and involve a significant numbers of iterative design steps. Composite interventional catheters deliver implants, facilitate the deployment of delicate therapeutic instruments, measure pressures and temperatures and can remove clots and foreign bodies. This paper summarizes the history of composite interventional catheters and the key evolutions in terms of materials and reinforcement structures. The current design practices, performance standards and general guidance available to assist composite interventional catheter design are reviewed. The environmental factors that affect the companies in which many of the leading edge interventional composite catheter designs are developed are also examined. A Predictive Modelling Framework is proposed to guide the design of composite interventional catheters to meet the key user needs. Two distinct but compatible methodologies are selected: The first method involves use of a DOE (Design of Experiments) approach to understand the influence of key variables on final catheter properties; The second involves the creation of customizable Finite Element models of the various potential catheter structures. The results of the predictive model constructed based on the DOE approach for braided composite catheters are presented and compared with experimental data. The DOE shows good alignment with experimental data in most cases. The sources of noise and error in the initial model are examined and potential improvements and learnings are discussed, with special focus on the results with poorer alignment.