Interventional device manufacturing has become a very lucrative business, emerging from the high-technology development in the medical field of minimal invasive surgery. Yet, designers face some serious problems which are causing development costs increase due to both faulty communication with the physicians and absence of a realistic environment to test and validate their concepts. In addition, new products are submitted to a long cycle of designing and testing before they can actually be used in the hospital. The Cath Works project, set up by the Institute of Systems Science in Singapore, therefore aims at improving the effectiveness of mechanical prototyping with application of the advanced technologies of computer visualisation, engineering analysis as well as design and image processing.
The Cath Works project has a threefold purpose. First, the researchers want to develop a comprehensive library of interventional devices and a professional referencing system for 3-D graphics-enhanced presentation. Second, they plan to build an interactive and feature-based environment for interventional device designing. Finally, they will search to provide a realistic model-based test-bed to validate the new products. They are primarily focusing on devices used for angiographic vascular catheterisation which are categorised according to their material, shape and length. These products have to be pliable, tortuous and possess both shape memory and multi-functionality.
As a consequence, the interactive Cath Works system will be based on the segmented vascular anatomy of the blood vessels. The team also will integrate real time Finite Element Modelling (FEM) analysis and graphic visualisation. The introduction of state-of-the-art CAD/CAM designing methods and of haptic feedback whenever the device is manipulated will transform the Cath Works system into a highly advanced toolkit. In order to simplify the design process, a parametric and variational model has already been developed.
In conventional solid modelling, there is no need for other information but the product's geometrical details. In interventional product design however, supplementary knowledge on function and material is indispensable. For this matter, the interventional devices are characterised by a number of salient parameters. This classification allows the research team to identify areas of objects that require special attention in the analysis because geometric relations, topological connectivities and physical properties are all taken into account.
This way of parametric modelling which associates engineering knowledge with geometry and topology in the product planning by means of constraints, is particularly suited for catheter designing. Whenever geometrical and/or topological variants are introduced to the model, the researchers only have to look at the predetermined sets of dimension values to create a part which corresponds to the respective standards. As a result, it is not only possible to perform design changes and simulation of product functions but also to calculate the optimisation of the parameter values in case constraints may appear. You can find more details on the Cath Works project at the web site of the Institute of Systems Science.