| abstract |
A high frictional resistance is secured against the inner wall of the digestive tract when the balloon is enlarged, and the frictional resistance against the inner wall is lowered when the diameter is reduced. An endoscope propulsion device is expanded by pressurization, contracted in the axial direction of an insertion portion, and restored to its original state when the pressurization is released. 28d. A sponge material 40 is provided on the outer peripheral surfaces of the first to fourth balloons 36a to 36d constituting the respective expansion / contraction units 28a to 28d, and at the positions where the balloons 36a to 36d are apexes when the balloons 36a to 36d are inflated. When each of the balloons 36a to 36d expands, the sponge material 40 is compressed between the inner wall of the digestive tract and the outer peripheral surface of the balloon, and the porous surface comes into direct contact with the inner wall. When each of the balloons 36a to 36d has a reduced diameter, the sponge material 40 absorbs the liquid in the digestive tract and forms a liquid layer on the surface thereof. [Selection] Figure 9 |