Patent ID: 8702591

Claim:
A capsule medical apparatus, comprising a capsule housing having a protruded portion on a longitudinal axis at one end, wherein the protruded portion is formed so that an outer surface of the protruded portion intersects perpendicularly with a first straight line, the first straight line substantially intersects with a second straight line connecting a center of buoyancy and a center of gravity when the capsule housing is in liquid in a body cavity, the first straight line and the second straight line substantially intersect at a balance point where a buoyant moment produced by buoyancy acting on the center of buoyancy and gravitational moment produced by gravity acting on the center of gravity are substantially balanced, an acute angle is formed by the first straight line and the second straight line, wherein either the balance point is positioned between an intersection of the first straight line and the outer surface of the protruded portion, and a center of curvature of the protruded portion at the intersection, the center of curvature being on a plane including the balance point, the intersection, and the center of buoyancy, or the intersection is positioned between the balance point and the center of curvature, and the capsule medical apparatus is configured to be in point contact with an inner wall of the body cavity at the intersection.