Managing the Effect of Manufacturing Variation in Medical Treatments

Licentiate thesis, 2008

To stay competitive in the market today, biomedical manufacturing companies must shorten their product realization time. These companies also deal with an increased demand for medical applications of high quality, from both the perspectives of user, government and internal requirements. This implies that many product aspects must be optimised in order to meet the higher demands. One important aspect that must be considered to meet the higher demands and stay competitive, and to optimize the mission-statement-to-product launch time, is how decisions made at the beginning of the process will have a great effect on the final product. This mean that complications should be found early and that methods that avoid complications ought to be implemented and used. One factor to consider early in the design phase is manufacturing variation, which affects the final geometrical quality to a high degree. Therefore, by designing robust solutions for the product, the manufacturing variation can be suppressed, consequently enabling possibilities for delivering high quality products. Moreover, one of the great challenges in biomedical applications is to offer possibilities to treat a wide range of patients. This means that individually manufactured components with individual geometries are often used according to mass-customization principles. That fact puts even greater demands on the whole product realisation process. Therefore, enabling methods for managing the effect of manufacturing variation, by means of variations simulation, to support the whole product realization process is of great value within biomedical device manufacturing. The objective of this research is to gain knowledge about how the product realization process, within medical device manufacturing, influences the final product from a geometrical perspective. Besides introducing the robust engineering field to medicine, new aspects in robust engineering have been explored by introducing individual geometries, by means of mass-customization, from medical treatments to the field of robust engineering To meet the objective, a variation simulation of the medical treatment method was carried out, and the model was verified against real data taken from actual surgeries. The treatment method was also studied with a focus on how to increase the robustness of the treatment method by re-engineering the existing treatment method. Knowledge of what parameters influence the final variation in the treatment method and an understanding of how parameters can be modeled to increase the robustness for the design have been gained. In addition, a geometry assurance method suitable for medical treatments using mass-customized products is suggested.