Stent
AssigneesTakao Itoi, Sb-Kawasumi Laboratories, Inc.
InventorsTakao Itoi, Noriaki Shirahama
Life of this patent
Estimating the term…
Abstract
Provided is a stent which is not easily displaced from a dwell site in a biological lumen and which has an excellent ability to follow a biological lumen. This stent (bile duct stent 100) is to dwell inside a biological lumen (bile duct B) and is provided with a stent main body section (110) having a cylindrical shape. The stent main body section is configured to be capable of expanding and contracting in the radial direction that is approximately orthogonal to an axial direction, has a relatively large expanding force in one portion (center portion) corresponding to the predetermined position at the indwelling site in the biological lumen, and a relatively small expanding force at other portions (both end portions) which have different positions in the axial direction from that of the one portion.
Claims4
A stent that is placed in a living body lumen, the stent comprising:
- a stent main body section including a skeleton portion formed into a cylindrical shape by spirally winding a wire rod;
- and
- a valve section provided in a downstream end portion of the stent main body section that is located downstream in a flow direction of a fluid flowing in the living body lumen, wherein
- the stent main body section is formed expandably and contractibly in a radial direction substantially orthogonal to an axial direction, and has a portion that corresponds to a predetermined position on an indwelling site in the living body lumen, the portion exerts a larger expanding force than at least one of two end portions that is different in axial position from the portion,
- the skeleton portion is bent in such a way that crest portions and trough portions are alternately formed in the axial direction, and includes a downstream skeleton portion located at the most downstream end of the skeleton portion,
- the crest portions of the downstream skeleton portion include two crest portions and other crest portions,
- the two crest portions face and separate each other in a first direction orthogonal to the axial direction,
- the other crest portions are disposed between the two crest portions in a circumferential direction,
- the two crest portions protrude more downstream in the flow direction than the other crest portions,
- the valve section has a membrane body forming an inlet and an outlet through which the fluid flows and two support portions supporting the membrane body, and has a tapered shape in which a width in a second direction orthogonal to the first direction in the axial cross section gradually decreases toward a downstream of the flow direction, and
- the two support portions are each formed in a V-shape by the two crest portions and apply force to the outlet to separate the two crest portions from each other along the first direction.
Dependencies are inferred from the claim text.