Endoscope system, endoscope, supporting member, and method of using endoscope system

An endoscope system comprising:

• a side-view endoscope including an elongated insertion portion, the elongated insertion portion including a bendable bending portion, a flexible tube portion having flexibility and provided on a proximal end side of the bendable bending portion, and a distal end portion provided on a distal end side of the bendable bending portion, wherein the elongated insertion portion is configured to be inserted into a lumen;
• four balloons which are expandable and contractable in a diameter direction of the elongated insertion portion in accordance with air feeding and air sucking by an air feeding/sucking device and which are disposed on a distal end side of the flexible tube portion, the balloons moving a one-side surface provided in the distal end portion in parallel to the diameter direction of the elongated insertion portion, separately from bending of the bending portion, the one-side surface being located in a circumferential direction of the distal end portion along an insertion direction of the elongated insertion portion and being parallel to a central axis of the elongated insertion portion;
• and
• an expansion/contraction mechanism provided in a linked manner to the four balloons and the air feeding/sucking device, and configured to expand and contract the four balloons,
• wherein:
• the four balloons are disposed in the circumferential direction on the distal end side of the flexible tube portion and include:
• a third balloon and a fourth balloon provided opposed to each other at line-symmetric positions with respect to a first axis passing the central axis of the elongated insertion portion and parallel to a field of view direction of an objective lens provided on the one-side surface, and
• a first balloon and a second balloon provided opposed to each other at line-symmetric positions with respect to a second axis passing the central axis of the elongated insertion portion and orthogonal to the first axis, and
• the expansion/contraction mechanism includes:
• a first balloon conduit having one end connected to the first balloon;
• a second balloon conduit having one end connected to the second balloon;
• a third balloon conduit having one end connected to the third balloon;
• a fourth balloon conduit having one end connected to the fourth balloon;
• and
• a syringe including:
• an introducing port for introducing air from the air feeding/sucking device,
• an introducing valve for changing over whether or not to introduce the air from the air feeding/sucking device into the introducing port,
• a first supply port on one end side of the syringe and a first valve,
• a second supply port on an other end side of the syringe and a second valve, and
• a piston movable between the one end side and the other end side,
• wherein, the first valve is connected with an other end of the first balloon conduit and an other end of the fourth balloon conduit, and the first valve changes over an air supply direction to supply the air inside the syringe to either the first balloon conduit or the fourth balloon conduit, and the second valve is connected with an other end of the second balloon conduit and an other end of the third balloon conduit, and the second valve changes over an air supply direction to supply the air in the syringe to either the second balloon conduit or the third balloon conduit,
• wherein the balloons are configured such that:
• in a state where the field of view direction of the objective lens and a protruding direction of a treatment instrument protruded from an aperture formed on the one-side surface coincide with each other by fixing a bending angle of the bendable bending portion, and in a state where the air supply direction is changed over to the first balloon conduit by the first valve, the air supply direction is changed over to the second balloon conduit by the second valve, the introducing valve is opened, and the piston is positioned in the syringe in the center between the one end side and the other end side of the syringe, when the air is supplied from the air feeding/sucking device to the first balloon and the second balloon via the introducing port, the syringe, the first supply port, the second supply port, the first balloon conduit, and the second balloon conduit, the first and second balloons expand in the diameter direction, and
• when the piston moves inside the syringe toward the one end side in a state where the introducing valve is closed, the air inside the second balloon is moved into the first balloon, via the second balloon conduit, the syringe, and the first balloon conduit, and thereby the second balloon contracts in the diameter direction and the first balloon expands in the diameter direction interlockingly with the contraction, thereby moving the one-side surface in parallel to a position close to a papilla with respect to the field of view direction of the objective lens by utilizing the expansion of the first balloon, while making the field of view direction of the objective lens and the protruding direction coincide with each other, and
• in a state where the field of view direction of the objective lens and the protruding direction of the treatment instrument protruded from the aperture formed on the one-side surface coincide with each other by fixing a bending angle of the bendable bending portion, and in a state where the air supply direction is changed over to the fourth balloon conduit by the first valve, the air supply direction is changed over to the third balloon conduit by the second valve, the introducing valve is opened, and the piston is positioned in the syringe in the center between the one end side and the other end side of the syringe, when the air is supplied from the air feeding/sucking device to the third balloon and the fourth balloon, via the introducing port, the syringe, the first supply port, the second supply port, the third balloon conduit and the fourth balloon conduit, the third and fourth balloons expand in the diameter direction, and
• when the piston moves inside the syringe toward the one end side in a state where the introducing valve is closed, the air inside the third balloon is moved into the fourth balloon via the third balloon conduit, the syringe, and the fourth balloon conduit, and thereby the third balloon contracts in the diameter direction and the fourth balloon expands in the diameter direction interlockingly with the contraction, thereby moving the one-side surface in parallel to the position close to the papilla with respect to the field of view direction of the objective lens by utilizing the expansion of the fourth balloon, while making the field of view direction of the objective lens and the protruding direction coincide with each other.