US 12,245,742 B2
Endoscope
Kensei Somekawa, Tokyo (JP)
Assigned to HOYA CORPORATION, Tokyo (JP)
Appl. No. 16/484,257
Filed by HOYA CORPORATION, Tokyo (JP)
PCT Filed Jan. 24, 2018, PCT No. PCT/JP2018/002061
§ 371(c)(1), (2) Date Aug. 7, 2019,
PCT Pub. No. WO2018/179737, PCT Pub. Date Oct. 4, 2018.
Claims priority of application No. 2017-072397 (JP), filed on Mar. 31, 2017.
Prior Publication US 2019/0374091 A1, Dec. 12, 2019
Int. Cl. A61B 1/00 (2006.01); A61B 1/005 (2006.01)
CPC A61B 1/00078 (2013.01) [A61B 1/0055 (2013.01); A61B 1/0016 (2013.01)] 14 Claims
OG exemplary drawing
 
1. An endoscope comprising
an endoscopic insertion unit affixed to an endoscopic operation unit, the endoscopic insertion unit having a first area and comprising:
a spiral tube comprising a spirally-wound metal strip;
a braided reticular tube surrounding the spiral tube;
a resin hull surrounding the braided reticular tube and comprising resin having a residual strain of 18% to 27%;
a resin outer coat surrounding the resin hull; and
a second area which is adjacent to a distal end side of the first area and has a higher attenuation rate than an attenuation rate of the first area, wherein
in the second area, the attenuation rate exponentially decreases from the distal end side toward the first area,
the first area is structured such that a repulsive force of the first area caused by bending the first area has an attenuation rate of a positive value equal to or less than 30 percent, the attenuation rate defined as a ratio between a repulsive force obtained immediately after bending the first area, and a repulsive force obtained after a state of bending the first area is maintained for three seconds, which is a period longer than a period of the repulsive force obtained immediately after bending, and
the attenuation rate is calculated by Formula (1) based on a repulsive force A immediately after pushing the insertion unit against a central point in a three-point bending tester with a spacing of 200 mm by 20 mm in a direction orthogonal to a length direction of the insertion unit and a repulsive force B after a lapse of three seconds from a state of being pushed by 20 mm:

OG Complex Work Unit Math
A is a maximum value of a repulsive force,
B is a repulsive force after three seconds from push, and
C is an attenuation rate (percentage) of a repulsive force at a position of abutment on a probe.