Parameter design was applied to the design of a disposable intravascular catheter with safety mechanism. Disposable intravascular catheters, like disposable medical devices in general, must combine multiple functions into a simple structure. In the design of this product, the problem was to determine parameters that would simultaneously stabilize three functions having different characteristics. The key point was the selection of optimal factor levels from the factorial effect diagrams obtained for each function by experiments. As this was a high risk medical device, the quality of all functions was equally important. To evaluate each function on an equal basis, functionality was evaluated with noise levels exceeding the anticipated range. The factorial effect diagrams of the functions were then combined to obtain the optimal conditions. It was confirmed that functionality of each function under the optimal conditions was stable,and the design of a safe intravascular catheter was completed using these conditions.
