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INDWELLING INSTRUMENT HAVING BISTABLE STRUCTURE FOR USE IN LUMINAL ORGAN meetings

Foreign code F180009570
File No. S2017-0385-C0
Posted date Nov 5, 2018
Country WIPO
International application number 2018JP008867
International publication number WO 2018164205
Date of international filing Mar 7, 2018
Date of international publication Sep 13, 2018
Priority data
  • P2017-043453 (Mar 8, 2017) JP
Title INDWELLING INSTRUMENT HAVING BISTABLE STRUCTURE FOR USE IN LUMINAL ORGAN meetings
Abstract A cylindrically shaped indwelling instrument (1) is formed into said cylindrical shape in the form of a mesh by linking a plurality of struts (3) in a circumferential direction in such a way as to share an axial direction rib (2), to form annular or helical rows, and linking the rows of the plurality of struts (3) at required locations in the axial direction by means of links (2a). Each strut (3) has at least one group of strut edges forming a bistable structure supporting a load resulting from an action of the indwelling instrument acting in a diametrically contracting direction, and a part which induces snap buckling deformation thereof. An action which acts in such a way as to diametrically contract the indwelling instrument imparts to the at least one group of strut edges forming the bistable structure a load in a direction impeding reverse snap buckling deformation. As a result, after the indwelling instrument has been introduced into the luminal organ, has been expanded diametrically and has been left in place, reverse snap buckling deformation is prevented and actions causing the indwelling instrument to contract diametrically are adequately resisted, making it possible for the diametrically expanded state to be reliably maintained.
Outline of related art and contending technology BACKGROUND ART
Such as cerebral infarction and myocardial infarction, therapy of disease by disease of the blood vessel, the stent is expanded by a balloon catheter placement of the blood vessel is performed.As the stent is made of metal is generally used, for a metal stent is permanently remain in the body so that they are, changes the size of the young but is applicable to, in addition, mechanical stimulation confined by the long risk of recurrence.Made of metal excellent in the strength of the stent is poor in flexibility, mechanical stimulation to the lumen wall of the blood vessel or the like, stress is easily given, resulting in thickening of the lumen wall in addition to, the metal remaining in the interior of the instrument is placed in a state in which the MRI (magnetic resonance imaging) diagnostic image in order to affect it is difficult to be referred to.
Made of the metal instrument is placed in the placement of the device becomes a problem to suppress the stress applied to the lumen, the stent biodegradable/bioabsorbable polymer stent in a living body by making permanently due to the presence of stress can be eliminated, and the like do not affect the MRI image of the point, can be solved the disadvantages of the metallic stents has the advantage that the, have recently been widely used in a stent made of polymer.
On the other hand, a polymeric stent, the stent as compared to a metal elastic modulus, low strength and hence to the contraction force is small, the creep deformation from the prone, deployment of a balloon-expandable to the diameter of the instrument after deployment because it is possible, further, a self-expanding placement of the instrument to maintain the contracted state for a long time, the larger the ratio of contraction or permanent deformation occurs in the case where the restoring extension, that is self-expanding may not be such that have a weakness.
Of a polymeric stent is placed into a tubular organ such as a blood vessel as a device, configured in a cylindrical shape, inserted into the tubular organ as the diameter-reduced state and, after placement of the diameter, so as to prevent narrowing of a tubular organ and acts, essentially of a polymer material or by a mesh structure of the struts to the circumferential direction of the cylindrical shape of the cell, aligned and extend in the axis direction becomes to have a structure formed.
Patent Document 1 is, in a spiral around the longitudinal axis of the helical elements extend in a wave-like, axially adjacent to the helical element extends from the peak of the peak portion of the column are connected by the cell is described for forming the stent, the stent is made of a metal and, due to the difficulty of metal.
Is Patent Document 2, a network structure of the struts of the plurality of waveform is formed in the circumferential direction without a ring, ring of the adjacent ridges and troughs of the waveform is coupled to the cell so as to form a tubular stent and are described, in the stent in such a configuration, the diameter of the material the ability to resist the action of attempting to increase the characteristic of an, made of a material having a low rigid material such as a polymer is by, the diameter of the action of the clot Thus, functions of the stent may not be able to hold.
Patent Document 3 is, the peak and valley are alternately arranged in the axial direction are formed so as to strut element in the circumferential direction to form a rounded cylindrical shape of the stent, each vertex of the strut element is formed to a convex portion provided with teeth, is inserted into the protruding portion of each valley formed in a plurality of vertices is formed and, each vertex of the convex portion vertex of the convex portions of the valley of the teeth can be inserted in the slit, the cylindrical stent diameter of the stent strut elements formed in a direction against the force of the shape such as a stent and apparatus which, in addition, in Patent Document 4, the slit is formed on one side of the head and the protrusion is formed like a hook to the sides of the shank T-shaped unit consisting of a plurality arranged side by side and rolled into a cylindrical shape, the head of the body portion and inserted into a slit, the hook-shaped protrusions in the body portion on opposite sides of the body portion by the action of variable to the slit to facilitate the insertion of a polymeric stent has been described.
Patent Document 3, the pawl 4, the slit engaged with the hook portion of the stent by a ratchet mechanism is held in the expanded state, or is used as a material film, the flexibility against bending is not obtained has a drawback.
Patent Document 5 is, as thick as the thin strut and the strut in combination with a series of spirally wound in a plurality of cells of the stent and the tubular, each cell is connected by a bridging element forms a bi-stable cell a stent has been described, in addition, in Patent Document 6, a link strut side in combination with a plurality of cells arranged in a mesh configured of a cylindrical polymeric stent, via the link connected thereto by a pulling action on the one side of the struts of the deformable from a stable state in the other stable state and having a bi-stability of a polymeric stent has been described.
Scope of claims (In Japanese)請求の範囲
[請求項1]
 複数のストラットが連結されて網目構造をなすように配設され全体として円筒形状をなすように形成された管腔臓器への留置器具であって、各ストラットはヒンジを介して複数のストラット辺を一体的に連結して構成されるとともに前記留置器具の拡径に応じて各ストラットが周方向に伸張するように変形するものであり、また、各ストラットは周方向への伸張の過程で一方の安定状態の形状から飛び移り座屈変形により他方の安定状態の形状に変位した状態で前記留置器具を縮径させようとする荷重を支える双安定構造をなす少なくとも一組のストラット辺を有し、他のストラット辺は各ストラットの周方向への伸張の過程で前記双安定構造をなす少なくとも1組のストラット辺の飛び移り座屈変形を誘起させる作用を有するように連結されており、飛び移り座屈変形後に前記留置器具を縮径させようとする荷重は前記双安定構造をなす少なくとも一組のストラット辺に逆向きの飛び移り座屈変形を妨げる作用を与え前記留置器具が縮径状態に戻ることを阻止して拡径状態を保持するものであることを特徴とする管腔臓器への留置器具。
[請求項2]
 前記各ストラットにおける双安定構造をなす少なくとも1組のストラット辺は前記留置器具の周方向に隣り合う2本のリブの間にかけ渡されるように連結された2本のストラット辺の間をヒンジで連結したものであり、前記双安定構造をなす少なくとも一組のストラット辺またはこれを連結するヒンジに前記少なくとも一組のストラット辺の飛び移り座屈変形を誘起させる他のストラット辺を含む部分が連結されていることを特徴とする請求項1に記載の管腔臓器への留置器具。
[請求項3]
 前記留置器具を構成するストラットの各々は、前記留置器具の周方向に隣り合う2つのストラットがリブを共有する形で略周方向に連結されてストラットの環状体をなし、複数の前記ストラットの環状体がリブ同士を要所でリンクにより連結することにより円筒形状の留置器具を形成するものであり、前記リンクが前記リブよりも屈曲し易い太さであることにより留置器具が全体として屈撓性を有するようにしたことを特徴とする請求項1または2のいずれかに記載の管腔臓器への留置器具。
[請求項4]
 留置器具の周方向に連結されたストラットの環状体と留置器具の軸方向に隣合う他のストラットの環状体との間でリブ同士を要所でリンクにより連結するに際して、周方向に1本以上のリブをあけて軸方向のリブ同士をリンクで連結し、周方向に間にあるリブ同士は連結されないようにすることにより留置器具における屈撓性が与えられることを特徴とする請求項3に記載の管腔臓器への留置器具。
[請求項5]
 前記留置器具を構成するストラットの各々は、前記留置器具の周方向に隣り合う2つのストラットがリブを共有する形で連結されてストラットの列をなし、該ストラットの列が螺旋状に旋回して延びて全体として円筒面を形成し、1ピッチだけ軸方向に前後するストラットの列におけるリブ同士を要所でリンクにより連結することにより円筒形状の留置器具を形成するものであり、前記リンクが前記リブよりも屈曲し易い太さであることにより留置器具が全体として屈撓性を有するようにしたことを特徴とする請求項1または2のいずれかに記載の管腔臓器への留置器具。
[請求項6]
 前記ストラットの列が螺旋方向に延びて形成された留置器具において、1ピッチだけ軸方向に前後するストラットの列におけるリブ同士を要所でリンクにより連結する際に、前記留置器具の周方向に連結されたストラットの列と、該ストラットの列に1ピツチだけ軸方向に前後して隣合うストラットの列との間でリブ同士を要所でリンクにより連結し、周方向に1本以上のリブをあけて軸方向のリブ同士をリンクで連結し、周方向に間にあるリブ同士は連結されないようにすることにより留置器具における屈撓性が与えられることを特徴とする請求項5に記載の管腔臓器への留置器具。
[請求項7]
 前記留置器具の縮径方向への作用による荷重を支える双安定構造をなす少なくとも一組のストラット辺の飛び移り座屈変形を誘起させる前記他のストラットを含む部分が前記留置器具の拡径の際に前記少なくとも一組のストラット辺の飛び移り座屈変形を誘起させつつ自ら飛び移り座屈変形する性質を有していることにより各ストラットが二重双安定構造を備えるものであることを特徴とする請求項2~6のいずれかに記載の管腔臓器への留置器具。
  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • YAMAGUCHI UNIVERSITY
  • INSTITUTE OF BIO-MEDICAL AND WELFARE ENGINEERING
  • Inventor
  • MINAMI Kazuyuki
IPC(International Patent Classification)

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