The colonoscopy heavily depends on the proficiency of the operator at present.For achieving an accurate and safe colonoscopy

the intelligent robotics is applied here for visual navigation of the colonoscopy.In this paper

a new visual navigation method for colonoscopy is described and tested

which is based on analyzing colon contours.For acquiring the precise edge energy of the colon contours

it uses steerable filters to detect the edge energy and the directions of the colon contours.Then it accumulates the edges' energy mapped in the normal directions of the edges.And by searching the area with highest accumulated energy

this method finds the center area formed by the curved contours. This method is designed to assist the visual navigation based on dark area analysis for reducing the possibility of navigation failure

which may be caused by the unsteadiness of the dark area.Some experimental results have demonstrated the effectiveness of this method for the assistance to the visual navigation for colonoscopy.