Mechanical properties of colon tissues are very important to prevent trauma and perforation during colonoscopy procedure. Most of forces are generated by the shaft of a colonoscope and a distal tip. A shaft of a colonoscope causes mechanical trauma at various locations. A distal tip of a colonoscope can cause not only for mechanical trauma but also serious perforation. In this study, elastic limits of forces were predicted for different sizes of a simplified shape of a tool tip end with a simple characteristic modeling. Published data on the various parts of a colon were used for the reference and a simple way of modeling was applied to estimate the quantity of forces with assumptions. Stress on Descending colon was used and a true stress-strain curve was generated. Descending colon has a wide range of a force limit for two different directions (longitudinal and lateral). A simple characteristic modeling was applied for a spherical shape of tool tip. Even though different parts of a colon and directions will generate diverse results, the model should be insensitive within a limited length and boundary conditions of a colon. The different radii of a tool tip end represent various tool ends from dull to sharp needle-type tool ends in several grades. The results show the elastic limit of force for different radii of tool tip end. The range of tool tip radius is between 0.1 and 10 mm. For the smallest radius of a tool tip, a colon wall will be perforated for a small force (less than 0.05N) and big forces were needed to damage the colon tissue when a tool tip diameter is more than 20 mm with the assumption that the boundary condition of a tool tip test should match up with the simple modeling statement. As the radius of a tool tip end is larger, the contact area between the interface area between a tool tip and a colon wall is wide enough to sustain applied forces. The structure of a human colon was briefly reviewed and determined the elastic limits of forces for different radii of tool ends.

This content is only available via PDF.
You do not currently have access to this content.