Medical Fixture Design with CT Images

Abstract

In line with the recent increased use of medical devices designed for individual patients, there is a need to ensure that the surfaces of bone fixtures match the bone surface to which they are fitted. Accordingly, this paper proposes a new process to design such fixtures from CT images using a two-stage process. The first stage involves extracting the outer bone surface of the relevant region from CT images using a level set method with a new speed function to remove the inner surface. In the second stage, a preliminary model designed using commercial CAD software is adopted to trim the extracted outer bone surface obtained in the first stage. The surface of the preliminary model to be attached to the bone is then shaped based on the trimmed outer bone surface to make the desired fixture. The results of experiments performed using the proposed method indicate its suitability for the purpose at hand.

Keywords:

• bio-CAD
• level set method
• CT images
• outer-surface extraction