JP4043731B2

JP4043731B2 - Endoscope

Info

Publication number: JP4043731B2
Application number: JP2001166934A
Authority: JP
Inventors: 隆一外山
Original assignee: Olympus Corp
Current assignee: Olympus Corp
Priority date: 2001-06-01
Filing date: 2001-06-01
Publication date: 2008-02-06
Anticipated expiration: 2021-06-01
Also published as: JP2002355217A

Description

【０００１】
【発明の属する技術分野】
本発明は、挿入部を構成する可撓管の曲げ硬度を調整する硬度調整機構を備えた内視鏡に関する。
【０００２】
【従来の技術】
近年、細長の挿入部を体腔内に挿入することにより、切開を必要とすることなく体腔内の検査対象部位を観察したり、必要に応じ、処置具を用いて治療処置のできる内視鏡が広く用いられるようになった。この内視鏡の挿入部は、Ｓ字状結腸のように屈曲の強い管腔では可撓性が高い（軟らかい）方が扱いやすく、横行結腸や下行結腸のように直線的で肛門から遠い管腔では逆に可撓性が低い（硬い）方が望ましいものの、従来、挿入部はある一定の硬さを有していた為、両方の要求に応えることが困難であった。
【０００３】
これに対処するために、例えば特開平１０−２４０１３号公報には、内視鏡の内部にコイルとワイヤとからなる可撓性調整手段（硬度調整機構）を設けたものが開示されている。この従来例の構成によれば、内視鏡検査を行う術者が、挿入部を挿入する部位に対して、挿入部を最も適切な可撓性に調整することを可能としている。
【０００４】
【発明が解決しようとする課題】
前述した先行技術のように、コイルをワイヤで牽引圧縮して硬度調整を行う機構では、一般に、コイル外径及びコイルの素線径が大きいほど、牽引したときの硬度の上昇が大きいという特性がある。
【０００５】
しかしながら、内視鏡の挿入部内には、処置具チャンネル、固体撮像素子の信号ケーブル、送気・送水チャンネル等の多くの内蔵物を設けなければならないこことから、硬度調整機構のコイル外径には制約があり、あまり大きくすることができない。そのため、挿入性の点で最も適当と思われる硬さまで、コイルの硬度を上げることが困難な場合があった。
【０００６】
本発明は上記事情に鑑みてなされたもので、可撓性調整のために内蔵されるコイルの制約に対して十分な硬度変化を確保し、挿入性を向上させることのできる内視鏡を提供することを目的としている。
【０００７】
【課題を解決するための手段】
上記目的を達成するため、本発明は、間隙を設けて螺旋状に巻いた円筒状帯部材と柔軟性の外皮部材とを少なくとも有する可撓管を挿入部に備え、前記可撓管内に長手軸方向に延設するコイルと、前記コイルの中に挿通したワイヤとを設け、前記ワイヤに張力を与えることで前記コイルに圧縮力をかけて前記可撓管の曲げ硬度を増加させる内視鏡において、前記外皮部材を全長で略同一の硬度を有するように構成すると共に、前記円筒状帯部材を、少なくとも一部の間隙が他の間隙と比較して小さくなるように構成し、前記ワイヤを、前記可撓管の先端に設けられた固定部材と前記可撓管の基端側に設けられて前記ワイヤに張力を与える牽引部材との間に張り渡し、前記ワイヤを牽引して張力を与えたときに前記円筒状帯部材の間隙を減少させるものである。
【０００８】
本発明による内視鏡は、ワイヤを牽引しない状態では、円筒状帯部材の間隙が小さい部分は撓みにくく間隙の大きい部分は相対的に柔軟であるため、各部の曲げ抵抗を適切に設定して挿入性を向上することができる。ワイヤを牽引操作すると、コイルに圧縮力が加わり曲げに対する抵抗が増すとともに、弾性変形により円筒状帯部材の間隙が牽引前よりも小さくなる。円筒状帯部材の間隙が小さくなると、可撓管を少し曲げただけでも帯部材同士が突き当たるようになり、それ以上湾曲させようとしても大きな曲げ抵抗が発生するようになるが、コイルの硬度が上がると同時に、牽引前の硬度の大小関係を維持しつつ可撓管自体の硬度も上がるため、挿入に適した硬さのバランスを保ちながらワイヤ牽引前より全体的に撓みづらくすることができ、挿入性を向上することが可能となる。
【０００９】
【発明の実施の形態】
以下、図面を参照して本発明の実施の形態を説明する。図１〜図６は本発明の実施の第１形態に係わり、図１は内視鏡の構造を示す断面図、図２はワイヤ牽引によるコイルの圧縮を示す説明図、図３はワイヤ牽引による可撓管の変形の様子を示す説明図、図４は可撓管が湾曲されたときの円筒状帯部材の変形状態を示す説明図、図５は硬度調整機構の変形例を示す説明図、図６は硬度調整機構の他の変形例を示す説明図である。
【００１０】
図１に示すように、本形態の内視鏡１は、体腔内等に挿入される細長の挿入部２と、この挿入部２の後端に設けられた操作部３と、この操作部３から延出されたユニバーサルコード４とを備えて構成される。挿入部２は、先端側から、硬質の先端部５、この先端部５の後端に形成され、湾曲自在な湾曲部６、この湾曲部６の後端に形成され、軟性で長尺の軟性部７が順次連結して構成され、軟性部７の基端（後端）は操作部３に連結されている。
【００１１】
挿入部２内には、照明光を伝送するライトガイドファイバ８が挿通されている。このライトガイドファイバ８は、多数の光学繊維を束ねたものであり、各光学繊維間には摩耗を防ぐための減摩剤が塗布されている。減摩剤としては、窒化ホウ素、カーボン、二硫化モリブデン等がある。ライトガイドファイバ８は、操作部３から延出されたユニバーサルコード４内を挿通され、一方の端部が先端部５を構成する先端硬質部材１２に設けられた図示しない照明窓に固定され、他方の端部がユニバーサルコード４の末端に設けたコネクタ９にパイプ部材１０を固定して形成されるライトガイド口金１１に固定されている。
【００１２】
そして、このライトガイド口金１１を図示しない光源装置に接続することにより、光源装置内のランプから供給された照明光をライトガイドファイバ８で伝送し、先端硬質部材１２の照明窓に固定されたライトガイドファイバ８の先端面から照明光を出射し、患部等の被写体を照明する。照明された被写体は、照明窓に隣接して形成された撮像窓としての撮像用孔１３に取り付けられた対物レンズ１４により、その結像位置に被写体像を結ぶ。この結像位置にはＣＣＤ等の固体撮像素子１５が配置され、結像された光学像を光電変換する。
【００１３】
固体撮像素子１５は、信号ケーブル１６を介してコネクタ９に設けられた電気コネクタ１７に接続され、この電気コネクタ１７を図示しないケーブルを介して図示しないビデオプロセッサに接続することにより、光電変換された撮像信号がビデオプロセッサ側に伝送される。そして、ビデオプロセッサで信号処理されて映像信号に変換され、図示しないモニタに入力されてモニタ画面に被写体像を表示することができる。
【００１４】
先端硬質部材１２には、湾曲部６を構成する最先端の湾曲駒１８ａが固定されている。この湾曲駒１８ａは、その後端の湾曲駒１８ｂに回動自在に連結され、この湾曲駒１８ｂは更に次の湾曲駒１８ｃに回動自在に連結されるという具合にして、複数の湾曲駒１８ａ，１８ｂ，１８ｃ，…，１８ｎが回動自在に連結されて湾曲部６が形成される。最後端の湾曲駒１８ｎは、軟性部７の境界部分に配置した接続管１９に固着されている。
【００１５】
これら湾曲駒１８ａ，１８ｂ，１８ｃ，…，１８ｎ内には、図示しない湾曲操作用ワイヤが挿通され、各湾曲操作用ワイヤの先端が最先端の湾曲駒１８ａに固着されると共に、各湾曲操作用ワイヤの後端が操作部３内の図示しないプーリ等の回転部材に連結されて湾曲機構を形成している。そして、この湾曲機構の回転部材の軸に連結された湾曲操作ノブを回動させることにより、湾曲操作用ワイヤを牽引、弛緩させ、湾曲駒１８ａ，１８ｂ，１８ｃ，…，１８ｎを、上（ＵＰ）、下（ＤＯＷＮ）、左（ＬＥＦＴ）、右（ＲＩＧＨＴ）の任意の方向に湾曲させることができる。これら湾曲駒１８ａ，１８ｂ，１８ｃ，…，１８ｎは、ゴムチューブ等の外皮チューブ２０で被覆されており、この外皮チューブ２０の先端は先端硬質部材１２に固着され、後端は接続管１９に固着されている。
【００１６】
また、挿入部２内には、処置具チャンネル２１が軟性のチャンネルチューブ２２で形成されている。このチャンネルチューブ２２の先端は先端硬質部材１２のチャンネル孔２３に固着されたパイプ材に固定され、チャンネルチューブ２２の後端は操作部３の先端付近で屈曲されて処置具挿入口２４に固着されている。この処置具挿入口２４は、処置具が使用されない場合には処置具栓２５で閉塞されている。
【００１７】
また、軟性部７は可撓管２７から形成され、この可撓管２７は、内側から円筒状帯部材２８、網状管２９、外皮３０の多層管構造になっている。円筒状帯部材２８は、帯状の弾性金属を等間隔で円筒螺旋状に成形したものであり、本形態では単層であるが、巻き方向の異なるものを二層以上設けるようにしても良い。網状管２９は、金属素線を円筒網状に編んだもので、その両端を円筒状帯部材２８の両端に対して半田で固着している。外皮３０は均一に成形された柔軟性樹脂であり、全長で略同一な硬度を有している。
【００１８】
軟性部７内の内蔵物としては、ライトガイドファイバ８、信号ケーブル１６、チャンネルチューブ２２等が挿通されているが、この他にも対物レンズ１４にノズルを介して空気を供給する送気チューブ、水を供給する送水チューブ等が内蔵されている。
【００１９】
また、本形態では、可撓管２７の硬度を調整する硬度調整機構が以下のように設けてある。すなわち、可撓管２７内及び操作部３内には、密巻状態のパイプ形状のコイル３４が長手軸方向で他の内蔵物にからみつく等の配置の乱れが生じないように配置されている。コイル３４は、円筒状帯部材２８の内壁に沿って挿通され、コイル３４の先端部がコイル３４内に挿通されるワイヤ３６の中途にろう２６で強固に固着されると共に、コイル３４の中途部が操作部３のケーシング３２の先端に固着される手元接続管３１の内壁にろう３５で固着され、操作部３後方側に延出されている。
【００２０】
ワイヤ３６は、硬度を調整するためコイル３４内に挿通されるものであり、ワイヤ３６の先端が可撓管２７の先端の固定部材としての接続管１９にろう３３で固着され、ワイヤ３６の後端がコイル３４の後端から後方側に延出されてワイヤ３６に張力を与える牽引部材としての操作棒３７に固着されている。操作棒３７は、操作部３の一部において露出し、図中、矢印で示すように、ワイヤ３６の軸方向に移動操作することのできる機構を形成している。
【００２１】
尚、ワイヤ３６の先端は、可撓管２７を直線状態にしたときに、ワイヤ３６がほぼ撓みなく張るように固定されている。そして、ワイヤ３６を牽引しない状態では、コイル３４は最も可撓性を有する状態であり、操作棒３７を牽引してワイヤ３６を引っ張ると、コイル３４に圧縮力が加えられて、屈曲することが抑えられる状態つまり硬度が高くなる状態に調整できるようにしている。
【００２２】
また、本形態では、コイル３４の先端をワイヤ３６の中途に固定するろう２６の位置を、可撓管２７の先端側よりもやや手元側にしている。従って、ワイヤ３６の先端を固定するろう３３と、コイル３４の先端をワイヤ３６の中途に固定するろう２６との間に形成される先端側ワイヤ部３６ａにおいて、その先端に近い部分の可撓管２７の内蔵部分はワイヤ３６を牽引しても硬さ変化を起こさないが、ろう２６に近づくにつれ、コイル３４の影響を受けて少しづつ硬さ変化が生じる。
【００２３】
すなわち、可撓管２７は、手元側は大きな硬さ変化幅を有するが、先端側は硬さ変化幅が小さい、或いは硬さが変化しないという、長手方向で硬さの変化幅が異なる構造となっている。換言すれば、可撓管２７は撓みやすい手元側で大きく硬さを上げることができ、一方、先端側は脾湾曲等の腸の屈曲部分を良好に通過させるためにあまり硬度を上げないように構成されており、単に可撓管２７の全長が均等に変化するよりも良好な挿入性を有している。
【００２４】
次に、以上の構成による内視鏡１の可撓管２７に対する硬度調整について説明する。
【００２５】
図２（ａ）は、コイル３４の初期状態を示す図であり、この初期状態から操作棒３７を手元側に牽引し、コイル３４に圧縮力を加えると、図２（ｂ）に示す状態になる。図２（ｂ）の状態では、コイル３４は圧縮力により弾性変形し、初期状態より図中Δｘで示した分だけ短くなる。コイル３４は素線同士が強く押し付けられているため、初期状態に比べて湾曲させる際に抵抗力が大きくなる。その為、この状態で可撓管２７を曲げると、初期状態よりも曲げの抵抗力が大きい状態、すなわち硬度が高い状態となる。
【００２６】
このとき、接続管１９は、ワイヤ３６，ろう３３を介して手元側にΔｘだけ牽引されている（このときワイヤ３６は若干伸びているので、実際には接続管１９の移動量はΔｘより僅かに少ないが、説明を簡単にするため、この減少分は無視する）。すなわち、可撓管２７は、初期長ｌに対して（ｌ−Δｘ）の長さに圧縮されている。
【００２７】
このときの可撓管２７の変形の様子を図３に示す。図３（ａ）は、ワイヤ３６を牽引する前の状態である。ワイヤ３６を牽引する前の状態では、円筒状帯部材２８は隣接する帯状板同士の間隙がｙであるものとし、ワイヤ３６を牽引すると、図３（ｂ）に示すように、円筒状帯部材２８の間隙がΔｙだけ減少する。それに合わせて、外皮３０は弾性変形により、また網状管２９は編み角を変化させながら、それぞれ長手方向に縮む。尚、縮むと同時に、外皮３０は内・外径方向に断面積を増加させ、また網状管２９は外径方向に経を変化させているが、これらの変形は長手方向の変化に比べると非常に小さいので、図３（ｂ）では省略して示している。
【００２８】
可撓管２７を湾曲させると、図４に示すように、ある湾曲半径ｒで円筒状帯部材２８の湾曲内側部分２８ａが互いに突き当たる。この湾曲内側部分２８ａ同士が突き当たらない程度の小さい湾曲半径では、外皮３０の湾曲内側部分の樹脂３０ａの圧縮と湾曲外側部分の樹脂３０ｂの伸びとの両方が生じているが、突き当たった後は、それ以上湾曲させると、突き当たり部分が支点となり、湾曲外側部分の樹脂３０ｂのみが大きく引き伸ばされる変形となる。従って、突き当たり前と比較して、曲げる際に大きな抵抗力が発生する。
【００２９】
よって、図３（ｂ）に示すように円筒状帯部材２８の間隙が小さくなると、可撓管２７を少し曲げただけでも円筒状帯部材２８同士が突き当たるようになるので、曲げに対して大きな抵抗力が発生する状態、すなわち可撓管２７の硬度が上がった状態となる。ワイヤ３６の牽引を元に戻すと、図３（ａ）の状態に戻り、初期状態の硬度に戻る。
【００３０】
すなわち、コイル３４は、コイル内径、素線径、牽引ストロークが大きいほど、圧縮時に強い曲げ抵抗を発生させるが、可撓管２７の内部には他にも多くの内蔵物がある為、これらを十分に大きく取れないことがある。このような場合でも、本構成によれば、硬度変化をコイル３４と可撓管２７との両方によって行うので、コイル３４の硬度変化が不十分であっても、可撓管２７の硬度変化により、目標とする硬度まで増加させることが可能となる。従って、横行結腸や下行結腸のように肛門から遠い管腔に対する挿入性が良好になる。
【００３１】
尚、可撓管２７の長手方向で硬度変化の大きさを変える別の硬度調整機構としては、例えば、図５に示す変形例による構造、或いは図６に示す他の変形例による構造を、コイル３４による構造の代わりに設けるようにしても良い。
【００３２】
図５に示す構造では、コイル３４に代えて、コイル３９と、このコイル３９よりも素線径及び内径の小さいコイル４０とを用い、コイル４０の後端をコイル３９の先端と当接させて、ろう４１で固着している。ろう４１は、コイル３９とコイル４０の内部に流れ出しておらず、両コイル３９，４０の内部は連通している。コイル３９，４０の内部には、ワイヤ３６が挿通されており、ろう４２でワイヤ３６とコイル４０の先端とが強固に固着されている。
【００３３】
図５に示す例では、ワイヤ３６を牽引すると、コイル３９とコイル４０とが圧縮されるが、コイル４０は素線径が小さいので、圧縮時の素線が発する反発力が小さい。従って、可撓管２７のコイル４０が内蔵されている部分の硬度変化は、コイル３９が内蔵されている部分の硬度変化より小さくなり、図１に示す構造よりも緩やかに長手方向の硬度変化の大きさを変えることができる。
【００３４】
他に、図６に示すように、図１，２で示したのと同構造で、長さのみが異なる複数のコイル４３，４３を並列して内蔵するようにする方法もある。
【００３５】
この場合は、先端部４４ａではあまり硬度変化せず、中間部４４ｂではコイル１本分の硬度変化、手元部４４ｃではコイル２本分の硬度変化が得られる。この構成によれば、先端、中間、後端と硬度変化の大きさが異なるため、図４と同様の効果が得られる他、１本のコイルで硬度変化させるよりも、小さい径のコイルを選択できるので、可撓管２７の内部の余った空間に設置可能で、可撓管２７の内部スペースの有効利用が可能であるというメリットもある。
【００３６】
尚、図５では２本のコイルを直列に、図６では２本のコイルを並列に配置しているが、コイルを３本以上にすると、長手方向の硬さ変化幅をより多様にすることができ、さらなる挿入性の改善につながる。また、図５では、手元側から先端に向かうにつれて硬度変化の小さいコイルを配置しているが、他にも各内視鏡の要求仕様に合わせて、大小のコイルを自由に組み合わせる方法も考えられる。例えば、可撓管２７内の内蔵物の充填率が高い部分だけに小さいコイルを配置し、その前後は大きいコイルを配置するようにしても良い。
【００３７】
次に、本発明の実施の第２形態について説明する。図７及び図８は本発明の実施の第２形態に係わり、図７は軟性部の構成を示す説明図、図８は円筒状帯部材の間隙の変化を示す説明図である。
【００３８】
図７に示すように、第２形態では、先端部５に湾曲部６を経て連結される軟性部７は、先端側から順に、先軟性部４５、硬さ変化部４６、元軟性部４７から構成されている。これらの先軟性部４５、硬さ変化部４６、元軟性部４７は、図８（ａ）に示すように、最外層にそれぞれ外皮５０、５１、５２を有し、その下層には、第１形態と同様、網状管２９、円筒状帯部材２８を共有している。円筒状帯部材２８は、帯状の弾性金属をｙ１の間隔で円筒螺旋状に巻くことで形成されている。
【００３９】
元軟性部４７の外皮５２の硬度は、先軟性部４５の外皮５０の硬度より高く、硬さ変化部４６の外皮５１は、その中間の硬度を有している。尚、第２形態では、外皮５０，５１，５２と、３段階の硬度変化をしているが、外皮５１の硬度を無段階に増加させる構成も考えられる。他の構成は、第１形態と同様である。
【００４０】
図８（ａ）に示すように、操作棒３７を牽引しない状態では、先軟性部４５は軟らかく、元軟性部４７は、それより硬くなっている。硬さ変化部４６は、その中間の硬さを有している。ここで、操作棒３７を手元側に牽引し、コイル３４に圧縮力を加えると、第１形態と同様の作用により、先軟性部４５、硬さ変化部４６、元軟性部４７は、それぞれ、図８（ｂ），（ｃ），（ｄ）に示される状態に圧縮され、円筒状帯部材２８の間隙がｙ２，ｙ３，ｙ４になる。先軟性部４５は、外皮５０の硬度が低いので圧縮量は大きい。元軟性部４７は、外皮５２の硬度が高いので圧縮量は小さい。硬さ変化部４６は、先軟性部４５と元軟性部４７との中間の圧縮量である。すなわち、先軟性部４５、硬さ変化部４６、元軟性部４７のそれぞれの円筒状帯部材２８の間隙ｙ２，ｙ３，ｙ４は、ｙ２＜ｙ３＜ｙ４の関係となる。
【００４１】
従って、操作棒３７を牽引した状態では、先軟性部４５は僅かに湾曲しただけで円筒状帯部材２８同士が突き当たり、曲がりづらくなるが、元軟性部４７は、湾曲させても円筒状帯部材２８同士が突き当たるまではある程度余裕があるので、それほど曲がりづらくはならない。硬さ変化部４６の曲がりづらさは、先軟性部４５と元軟性部４７の中間となる。つまり、操作棒３７を牽引した際に、可撓管２７の牽引前から軟らかい部分は十分曲げ抵抗が大きくなるが、可撓管２７の牽引前から硬い部分は、あまり曲げ抵抗が大きくならない構成となっている。
【００４２】
第２形態では、第１形態の効果に加え、次の効果がある。すなわち、操作棒３７を牽引しない状態でも、元軟性部４７は撓みにくいため、第１形態に比べ挿入性は良好である。更に、操作棒３７を牽引しても元軟性部４７が硬くなり過ぎることがないため、挿入部２が硬くなり過ぎて患者の不快感が増加することがない。一方、先軟性部４５，硬さ変化部４６は、十分硬くなり全体的に撓みにくくなるため、横行結腸や下行結腸のように肛門から遠い管腔に対する挿入性は、ワイヤ３６を牽引しない状態よりも大きく向上する。
【００４３】
尚、図８（ａ）に示す円筒状帯部材２８の間隙ｙ１を元軟性部４７だけ小さく設定すれば、元軟性部４７の曲げ抵抗が更に大きくなって撓み防止の効果が高くなるので、更に挿入性を向上させることが可能である。
【００４４】
次に、本発明の実施の第３形態について説明する。図９は本発明の実施の第３形態に係わり、円筒帯状部材の間隙の変化を示す説明図である。
【００４５】
第３形態は、前述の第２形態に対し、先軟性部４５、硬さ変化部４６、元軟性部４７の最内層の円筒状帯部材の構成を若干変更するものである。すなわち、図９（ａ），（ｂ），（ｃ）に示すように、先軟性部４５、硬さ変化部４６、元軟性部４７は、第１形態と同様、外皮５０、網状管２９を共有し、最内層に、それぞれ円筒状帯部材５３，５４，５５を有している。円筒状帯部材５３，５４，５５は、帯状の弾性金属をそれぞれｙ５、ｙ６、ｙ７の間隙で円筒螺旋状に巻くことで形成されている。この間隙の大きさの関係は、ｙ５＞ｙ６＞ｙ７である。
【００４６】
第３形態では、操作棒３７を牽引しない状態では、先軟性部４５は円筒状帯部材５３の間隙が元軟性部４７の円筒状帯部材５５より大きいので、少し湾曲しただけでも曲げ抵抗が生じやすい。逆に、元軟性部４７は、曲げ抵抗が生じるまでの余裕が大きい。硬さ変化部４６は、その中間の曲げ抵抗である。
【００４７】
操作棒３７を手元側に牽引し、コイル３４に圧縮力を加えると、第１形態と同様の作用により、先軟性部４５、硬さ変化部４６、元軟性部４７は、それぞれ図９（ｄ），（ｅ），（ｆ）に示される状態に圧縮される。牽引後の円筒状帯部材５３，５４，５５の間隙は、ｙ８、ｙ９、ｙ１０になっており、それぞれ牽引前より短縮されている。この場合、外皮５０は、共通で同様の硬度を有しているため、圧縮力により円筒状帯部材５３，５４，５５はほぼ同程度に短縮される。よって、ｙ８、ｙ９、ｙ１０の大きさの関係は、ｙ８＞ｙ９＞ｙ１０となる。
【００４８】
操作棒３７を牽引した状態では、先軟性部４５は少し湾曲すると円筒状帯部材５３同士が突き当たって曲がりづらくなるが、元軟性部４７は、それ以上に僅かに湾曲させただけでも円筒状帯部材５５同士が突き当たるようになる。硬さ変化部４６は、その中間の湾曲で円筒状帯部材５４同士が突き当たる。つまり、操作棒３７を牽引した際に、牽引前の硬度の大小関係を維持しつつ、全体的に可撓管２７が硬くなる。
【００４９】
第３形態では、第１形態の効果に加え、次の効果がある。すなわち、操作棒３７を牽引しない状態でも、元軟性部４７は撓みにくく、しかも先軟性部４５は柔軟である。従って、操作棒３７を牽引しない状況において、第１形態に比べ挿入性が良好である。更に、操作棒３７を牽引した後も、先端側が軟らかく手元側が硬いという挿入に適した硬さのバランスを保ちながら、ワイヤ牽引前より全体的に撓みづらくなるので、横行結腸や下行結腸のように肛門から遠い管腔に対する挿入性は第２形態よりも更に向上する。
【００５０】
[付記]
（付記項１）
間隙を設けて螺旋状に巻いた円筒状帯部材と柔軟性の外皮部材とを少なくとも有する可撓管を挿入部に備え、前記可撓管内に長手軸方向に延設するコイルと、前記コイルの中に挿通したワイヤとを設け、前記ワイヤに張力を与えることで前記コイルに圧縮力をかけて前記可撓管の曲げ硬度を増加させる内視鏡において、前記ワイヤを、前記可撓管の先端に設けられた固定部材と前記可撓管の基端側に設けられて前記ワイヤに張力を与える牽引部材との間に張り渡し、前記ワイヤを牽引して張力を与えたときに前記円筒状帯部材の間隙を減少させることを特徴とする内視鏡。
【００５１】
（付記項２）
付記項１において、前記外皮部材は、少なくとも一部の硬度が他の部分の硬度と比較して高いことを特徴とする内視鏡。
【００５２】
（付記項３）
付記項２において、前記外皮部材の硬度が他の部分よりも高い部分に位置する前記円筒状帯部材は、他の部分と比較して間隙が小さいことを特徴とする内視鏡。
【００５３】
（付記項４）
付記項１において、前記外皮部材は全長で略同一の硬度を有しており、前記円筒状帯部材は、少なくとも一部の間隙が他の間隙と比較して小さいことを特徴とする内視鏡。
【００５４】
（作用）
付記項１の内視鏡は、ワイヤを牽引操作すると、コイルに圧縮力が加わり曲げに対する抵抗が増すとともに、弾性変形により円筒状帯部材の間隙が小さくなる。円筒状帯部材の間隙が小さくなると、可撓管を少し曲げただけでも帯部材同士が突き当たるようになり、それ以上湾曲させようとしても大きな曲げ抵抗が発生するようになる。すなわち、コイルの硬度が上がると同時に、可撓管自体の硬度も上がる。
【００５５】
付記項２，３の内視鏡は、付記項１の内視鏡の作用に加え、外皮部材の硬度が高い部分の可撓管は、それが低い部分と比べて圧縮されにくい。従って、外皮部材の硬度が高い部部は、ワイヤを牽引しても円筒状帯部材の間隙があまり小さくならず、その間隙が小さくなることにより、曲げ抵抗が増す作用は抑えられている。
【００５６】
付記項４の内視鏡は、付記項１の内視鏡の作用に加え、外皮部材の硬度は全長で略同一なので、円筒状帯部材は全体的に圧縮される。したがってワイヤを牽引する前から存在する円筒状帯部材の間隙の大小関係は、ワイヤ牽引後も変わらない。
【００５７】
（効果）
付記項１の内視鏡は、コイルに加えて可撓管自体が硬質化するので、他の内蔵物の制約等からコイルだけでは硬度変化が不十分であっても、挿入部全体としては十分な硬度変化が可能となり、挿入性が向上する。
【００５８】
付記項２の内視鏡は、付記項１の内視鏡の効果に加え、部分的に外皮部材の硬度を高くすることで、ワイヤを牽引していない状態でも撓み防止等の挿入性の向上が図れる。ワイヤを牽引すると、外皮部材の硬度を高くした部分が硬くなり過ぎることがないため、それにより内視鏡を挿入している患者の不快感が増加することがない。外皮部材の硬度を高くした以外の部分は十分曲げ抵抗が増すため、全体的に撓みにくくなり、ワイヤを牽引していない状態よりも更に挿入性が向上する。
【００５９】
付記項３の内視鏡は、付記項２の内視鏡の効果に加え、付記項２の内視鏡よりも更に外皮部材の硬度を高くした部分が撓みにくくなるため、更なる挿入性の向上が期待できる。
【００６０】
付記項４の内視鏡は、付記項１の内視鏡の効果に加え、ワイヤを牽引すると挿入に適した硬さのバランスを保ちながら全体的に曲げ抵抗が増加するので、付記項２，３の内視鏡よりも更に挿入性が良好となる。
【００６１】
【発明の効果】
以上説明したように本発明によれば、コイルに加えて可撓管自体が硬質化するので、他の内蔵物の制約等からコイルだけでは硬度変化が不十分であっても、挿入部全体としては十分な硬度変化が可能となり、挿入性が向上する等優れた効果が得られる。
【図面の簡単な説明】
【図１】本発明の実施の第１形態に係わり、内視鏡の構造を示す断面図
【図２】同上、ワイヤ牽引によるコイルの圧縮を示す説明図
【図３】同上、ワイヤ牽引による可撓管の変形の様子を示す説明図
【図４】同上、可撓管が湾曲されたときの円筒状帯部材の変形状態を示す説明図
【図５】同上、硬度調整機構の変形例を示す説明図
【図６】同上、硬度調整機構の他の変形例を示す説明図
【図７】本発明の実施の第２形態に係わり、軟性部の構成を示す説明図
【図８】同上、円筒状帯部材の間隙の変化を示す説明図
【図９】本発明の実施の第３形態に係わり、円筒帯状部材の間隙の変化を示す説明図
【符号の説明】
１内視鏡
２挿入部
１９接続管
２７可撓管
２８円筒状帯部材
３０外皮
３４コイル
３６ワイヤ
３７操作棒[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an endoscope provided with a hardness adjusting mechanism that adjusts the bending hardness of a flexible tube constituting an insertion portion.
[0002]
[Prior art]
2. Description of the Related Art In recent years, an endoscope capable of observing a region to be examined in a body cavity without requiring an incision by inserting an elongated insertion portion into the body cavity, or performing a therapeutic treatment using a treatment tool as necessary. Widely used. The insertion part of this endoscope is a more flexible (softer) tube with a strong bend like the sigmoid colon, which is easier to handle, and is a straight tube far from the anus like the transverse and descending colons. On the other hand, although it is desirable that the cavity has low flexibility (hard), the insertion portion has conventionally had a certain hardness, so it has been difficult to meet both requirements.
[0003]
In order to cope with this, for example, Japanese Patent Application Laid-Open No. 10-24013 discloses an endoscope in which a flexible adjusting means (hardness adjusting mechanism) including a coil and a wire is provided. According to the configuration of this conventional example, an operator who performs endoscopy can adjust the insertion portion to the most appropriate flexibility with respect to the portion where the insertion portion is inserted.
[0004]
[Problems to be solved by the invention]
In the mechanism that adjusts the hardness by pulling and compressing a coil with a wire as in the prior art described above, generally, the larger the outer diameter of the coil and the wire diameter of the coil, the greater the increase in hardness when pulled. is there.
[0005]
However, from the point where many built-in items such as the treatment instrument channel, the signal cable of the solid-state image sensor, and the air / water supply channel must be provided in the insertion portion of the endoscope, the coil outer diameter of the hardness adjusting mechanism is reduced. Is limited and cannot be made too large. Therefore, it may be difficult to increase the hardness of the coil to the hardness that seems to be most appropriate in terms of insertability.
[0006]
The present invention has been made in view of the above circumstances, and provides an endoscope capable of ensuring sufficient change in hardness against the restriction of a coil built in for flexibility adjustment and improving insertability. The purpose is to do.
[0007]
[Means for Solving the Problems]
To achieve the above objective, The present invention Includes a flexible tube having at least a cylindrical belt member spirally wound with a gap and a flexible outer skin member in an insertion portion, and a coil extending in a longitudinal axis direction in the flexible tube; In an endoscope in which a wire inserted into a coil is provided and a bending force of the flexible tube is increased by applying a compressive force to the coil by applying tension to the wire. The outer skin member is configured to have substantially the same hardness over its entire length, and the cylindrical belt member is configured such that at least some of the gaps are smaller than other gaps, The wire is stretched between a fixing member provided at a distal end of the flexible tube and a pulling member provided on a proximal end side of the flexible tube to apply tension to the wire, and the wire is pulled When a tension is applied, the gap between the cylindrical belt members is reduced.
[0008]
The present invention Endoscopes with, when the wire is not pulled, the part with a small gap of the cylindrical belt member is hard to bend and the part with a large gap is relatively flexible. Can be improved. When the wire is pulled, a compression force is applied to the coil to increase the resistance to bending, and the gap between the cylindrical belt members becomes smaller than that before towing due to elastic deformation. If the gap between the cylindrical band members is reduced, the band members will come into contact with each other even if the flexible tube is bent a little, and a large bending resistance will be generated even if it is further bent, but the hardness of the coil is reduced. At the same time, since the hardness of the flexible tube itself increases while maintaining the magnitude relationship of the hardness before towing, it can be harder to bend overall than before towing the wire while maintaining the balance of hardness suitable for insertion, Insertability can be improved.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 to 6 relate to a first embodiment of the present invention, FIG. 1 is a sectional view showing the structure of an endoscope, FIG. 2 is an explanatory view showing compression of a coil by wire pulling, and FIG. 3 is by wire pulling FIG. 4 is an explanatory view showing a deformation state of the flexible tube, FIG. 4 is an explanatory view showing a deformation state of the cylindrical belt member when the flexible tube is bent, and FIG. 5 is an explanatory view showing a modification of the hardness adjusting mechanism. FIG. 6 is an explanatory view showing another modification of the hardness adjusting mechanism.
[0010]
As shown in FIG. 1, an endoscope 1 of this embodiment includes an elongated insertion portion 2 that is inserted into a body cavity or the like, an operation portion 3 provided at the rear end of the insertion portion 2, and the operation portion 3. And a universal cord 4 extended from the head. The insertion portion 2 is formed from the distal end side to the hard distal end portion 5 and the rear end of the distal end portion 5, and is formed to the bendable bending portion 6 and the rear end of the bending portion 6. The parts 7 are sequentially connected, and the base end (rear end) of the flexible part 7 is connected to the operation unit 3.
[0011]
A light guide fiber 8 that transmits illumination light is inserted into the insertion portion 2. The light guide fiber 8 is a bundle of a number of optical fibers, and a lubricant is applied between the optical fibers to prevent wear. Examples of the lubricant include boron nitride, carbon, and molybdenum disulfide. The light guide fiber 8 is inserted through the universal cord 4 extended from the operation portion 3, and one end portion is fixed to an illumination window (not shown) provided on the distal end hard member 12 constituting the distal end portion 5. Is fixed to a light guide base 11 formed by fixing a pipe member 10 to a connector 9 provided at the end of the universal cord 4.
[0012]
Then, by connecting the light guide base 11 to a light source device (not shown), the illumination light supplied from the lamp in the light source device is transmitted by the light guide fiber 8 and is fixed to the illumination window of the distal end hard member 12. Illumination light is emitted from the distal end surface of the guide fiber 8 to illuminate a subject such as an affected part. The illuminated subject forms a subject image at its imaging position by an objective lens 14 attached to an imaging hole 13 as an imaging window formed adjacent to the illumination window. A solid-state image sensor 15 such as a CCD is disposed at the image formation position, and photoelectrically converts the formed optical image.
[0013]
The solid-state imaging device 15 is connected to an electrical connector 17 provided on the connector 9 via a signal cable 16 and is photoelectrically converted by connecting the electrical connector 17 to a video processor (not shown) via a cable (not shown). An imaging signal is transmitted to the video processor side. Then, the signal is processed by a video processor, converted into a video signal, and input to a monitor (not shown) to display a subject image on a monitor screen.
[0014]
The leading edge bending member 18 a constituting the bending portion 6 is fixed to the distal end hard member 12. The bending piece 18a is rotatably connected to the bending piece 18b at the rear end, and the bending piece 18b is further connected to the next bending piece 18c so as to be rotatable. 18b, 18c,..., 18n are rotatably connected to form the bending portion 6. The rearmost bending piece 18n is fixed to a connecting pipe 19 disposed at the boundary portion of the soft part 7.
[0015]
A bending operation wire (not shown) is inserted into the bending pieces 18a, 18b, 18c,..., 18n, and the distal end of each bending operation wire is fixed to the most advanced bending piece 18a, and for each bending operation. The rear end of the wire is connected to a rotating member such as a pulley (not shown) in the operation unit 3 to form a bending mechanism. Then, by rotating the bending operation knob connected to the axis of the rotating member of the bending mechanism, the bending operation wire is pulled and relaxed, and the bending pieces 18a, 18b, 18c,. ), Down (DOWN), left (LEFT), and right (RIGHT). .., 18n are covered with an outer tube 20 such as a rubber tube. The outer tube 20 is fixed to the distal end rigid member 12 and the rear end is fixed to the connecting tube 19. Has been.
[0016]
Further, a treatment instrument channel 21 is formed by a flexible channel tube 22 in the insertion portion 2. The distal end of the channel tube 22 is fixed to a pipe material fixed to the channel hole 23 of the distal end rigid member 12, and the rear end of the channel tube 22 is bent near the distal end of the operation unit 3 and fixed to the treatment instrument insertion port 24. ing. The treatment instrument insertion port 24 is closed with a treatment instrument plug 25 when the treatment instrument is not used.
[0017]
The flexible portion 7 is formed of a flexible tube 27. The flexible tube 27 has a multilayer tube structure of a cylindrical belt member 28, a mesh tube 29, and an outer skin 30 from the inside. The cylindrical band member 28 is formed by forming a band-shaped elastic metal into a cylindrical spiral shape at equal intervals. In this embodiment, the cylindrical band member 28 is a single layer, but two or more layers having different winding directions may be provided. The mesh tube 29 is made by braiding metal strands into a cylindrical mesh shape, and both ends thereof are fixed to both ends of the cylindrical belt member 28 by soldering. The outer skin 30 is a uniformly shaped flexible resin and has substantially the same hardness over its entire length.
[0018]
The light guide fiber 8, the signal cable 16, the channel tube 22, etc. are inserted as built-in items in the flexible portion 7, but in addition to this, an air supply tube that supplies air to the objective lens 14 through a nozzle, A water supply tube for supplying water is built in.
[0019]
In this embodiment, a hardness adjusting mechanism for adjusting the hardness of the flexible tube 27 is provided as follows. That is, in the flexible tube 27 and the operation unit 3, the closely wound pipe-shaped coil 34 is arranged so as not to be disturbed in arrangement such as entangled with other built-in objects in the longitudinal axis direction. The coil 34 is inserted along the inner wall of the cylindrical belt member 28, and the distal end portion of the coil 34 is firmly fixed by the wax 26 in the middle of the wire 36 that is inserted into the coil 34, and the middle portion of the coil 34. Is fixed to the inner wall of the hand connection pipe 31 fixed to the tip of the casing 32 of the operation unit 3 with a wax 35 and extends to the rear side of the operation unit 3.
[0020]
The wire 36 is inserted into the coil 34 in order to adjust the hardness, and the tip of the wire 36 is fixed to the connecting tube 19 as a fixing member at the tip of the flexible tube 27 with a braze 33. The end extends from the rear end of the coil 34 to the rear side, and is fixed to an operation rod 37 as a pulling member that applies tension to the wire 36. The operation bar 37 is exposed at a part of the operation unit 3 and forms a mechanism that can be moved and operated in the axial direction of the wire 36 as indicated by an arrow in the drawing.
[0021]
The tip of the wire 36 is fixed so that the wire 36 is stretched substantially without bending when the flexible tube 27 is in a straight line state. When the wire 36 is not pulled, the coil 34 is in the most flexible state. When the operating rod 37 is pulled and the wire 36 is pulled, a compression force is applied to the coil 34 and the coil 34 can be bent. It is possible to adjust to a suppressed state, that is, a state where the hardness is increased.
[0022]
Further, in this embodiment, the position of the solder 26 that fixes the tip of the coil 34 in the middle of the wire 36 is slightly closer to the proximal side than the tip of the flexible tube 27. Therefore, in the distal end side wire portion 36a formed between the solder 33 for fixing the distal end of the wire 36 and the solder 26 for fixing the distal end of the coil 34 in the middle of the wire 36, a flexible tube at a portion near the distal end. The built-in portion 27 does not change in hardness even when the wire 36 is pulled, but as it approaches the wax 26, the hardness changes little by little due to the influence of the coil 34.
[0023]
That is, the flexible tube 27 has a large hardness change width on the hand side but a small hardness change width on the distal end side or a structure in which the hardness change width is different in the longitudinal direction. It has become. In other words, the flexible tube 27 can be greatly increased in hardness on the proximal side where it is easy to bend, while the distal end side is not so increased in hardness in order to pass the bent portion of the intestine such as a spleen curve well. It is configured and has better insertability than simply changing the entire length of the flexible tube 27 evenly.
[0024]
Next, the hardness adjustment for the flexible tube 27 of the endoscope 1 having the above configuration will be described.
[0025]
2A is a diagram showing an initial state of the coil 34. When the operating rod 37 is pulled toward the hand side from this initial state and a compression force is applied to the coil 34, the state shown in FIG. 2B is obtained. Become. In the state of FIG. 2B, the coil 34 is elastically deformed by the compressive force, and is shorter than the initial state by the amount indicated by Δx in the figure. Since the coils 34 are strongly pressed against each other, the resistance increases when the coil 34 is bent compared to the initial state. Therefore, when the flexible tube 27 is bent in this state, the bending resistance is greater than the initial state, that is, the hardness is higher.
[0026]
At this time, the connecting pipe 19 is pulled by Δx toward the hand side via the wire 36 and the wax 33 (at this time, since the wire 36 is slightly extended, the movement amount of the connecting pipe 19 is actually slightly smaller than Δx. But for the sake of simplicity, ignore this decrease.) That is, the flexible tube 27 is compressed to a length of (l−Δx) with respect to the initial length l.
[0027]
The state of deformation of the flexible tube 27 at this time is shown in FIG. FIG. 3A shows a state before the wire 36 is pulled. In the state before the wire 36 is pulled, the cylindrical band member 28 is assumed to have a gap y between adjacent band plates, and when the wire 36 is pulled, as shown in FIG. 28 gaps are reduced by Δy. Accordingly, the outer skin 30 is contracted in the longitudinal direction by elastic deformation, and the mesh tube 29 is contracted in the longitudinal direction while changing the knitting angle. At the same time as the shrinkage, the outer skin 30 increases the cross-sectional area in the inner and outer diameter directions, and the mesh tube 29 changes the warp in the outer diameter direction. Therefore, the illustration is omitted in FIG.
[0028]
When the flexible tube 27 is curved, as shown in FIG. 4, the curved inner portions 28a of the cylindrical belt member 28 abut each other with a certain curvature radius r. At such a small radius of curvature that the curved inner portions 28a do not collide with each other, both the compression of the resin 30a of the curved inner portion of the outer skin 30 and the elongation of the resin 30b of the curved outer portion occur. If it is further bent, the abutting portion becomes a fulcrum, and only the resin 30b in the outer portion of the curve is deformed to be greatly stretched. Therefore, a greater resistance force is generated when bending compared to before the end.
[0029]
Therefore, as shown in FIG. 3B, when the gap between the cylindrical belt members 28 becomes small, the cylindrical belt members 28 come into contact with each other even if the flexible tube 27 is bent a little. A state in which a resistance force is generated, that is, a state in which the hardness of the flexible tube 27 is increased is obtained. When the traction of the wire 36 is restored, the state returns to the state of FIG. 3A and returns to the initial hardness.
[0030]
That is, the larger the coil inner diameter, the wire diameter, and the traction stroke, the stronger the coil 34 generates a bending resistance during compression. It may not be large enough. Even in such a case, according to the present configuration, since the hardness change is performed by both the coil 34 and the flexible tube 27, even if the hardness change of the coil 34 is insufficient, the hardness change of the flexible tube 27 is caused. It is possible to increase to a target hardness. Therefore, insertion into a lumen far from the anus such as the transverse colon and the descending colon is improved.
[0031]
As another hardness adjustment mechanism for changing the magnitude of the hardness change in the longitudinal direction of the flexible tube 27, for example, a structure according to the modification shown in FIG. 5 or a structure according to another modification shown in FIG. Instead of the structure of 34, it may be provided.
[0032]
In the structure shown in FIG. 5, instead of the coil 34, a coil 39 and a coil 40 having a wire diameter and an inner diameter smaller than that of the coil 39 are used, and the rear end of the coil 40 is brought into contact with the front end of the coil 39. It is fixed with the wax 41. The wax 41 does not flow out into the coils 39 and 40, and the insides of both the coils 39 and 40 are in communication. A wire 36 is inserted into the coils 39 and 40, and the wire 36 and the tip of the coil 40 are firmly fixed by a braze 42.
[0033]
In the example shown in FIG. 5, when the wire 36 is pulled, the coil 39 and the coil 40 are compressed. However, since the coil 40 has a small wire diameter, the repulsive force generated by the wire during compression is small. Accordingly, the hardness change of the portion of the flexible tube 27 in which the coil 40 is built is smaller than the hardness change of the portion in which the coil 39 is built, and the hardness change in the longitudinal direction is more gradual than the structure shown in FIG. You can change the size.
[0034]
In addition, as shown in FIG. 6, there is a method in which a plurality of coils 43, 43 having the same structure as shown in FIGS.
[0035]
In this case, the hardness does not change so much at the tip end portion 44a, the hardness change for one coil is obtained at the intermediate portion 44b, and the hardness change for two coils is obtained at the hand portion 44c. According to this configuration, since the magnitude of the hardness change is different from the front, middle, and rear ends, the same effect as in FIG. 4 can be obtained, and a coil having a smaller diameter than that of changing the hardness with one coil is selected. Therefore, there is also an advantage that it can be installed in a surplus space inside the flexible tube 27 and the internal space of the flexible tube 27 can be used effectively.
[0036]
In FIG. 5, two coils are arranged in series, and in FIG. 6, two coils are arranged in parallel. However, if three or more coils are used, the width of change in hardness in the longitudinal direction can be made more diverse. Can lead to further improved insertion. In FIG. 5, coils with a small hardness change are arranged from the hand side to the tip, but other methods of freely combining large and small coils are also conceivable according to the required specifications of each endoscope. . For example, a small coil may be disposed only in a portion where the filling rate of the built-in material in the flexible tube 27 is high, and a large coil may be disposed before and after that.
[0037]
Next, a second embodiment of the present invention will be described. 7 and 8 relate to a second embodiment of the present invention, FIG. 7 is an explanatory view showing the configuration of the flexible portion, and FIG. 8 is an explanatory view showing a change in the gap of the cylindrical belt member.
[0038]
As shown in FIG. 7, in the second embodiment, the flexible portion 7 connected to the distal end portion 5 via the bending portion 6 starts from the distal flexible portion 45, the hardness changing portion 46, and the original flexible portion 47 in order from the distal end side. It is configured. As shown in FIG. 8 (a), the tip soft portion 45, the hardness changing portion 46, and the former soft portion 47 have outer skins 50, 51, 52 in the outermost layer, respectively. Similar to the embodiment, the mesh tube 29 and the cylindrical belt member 28 are shared. The cylindrical band member 28 is formed by winding a band-shaped elastic metal in a cylindrical spiral shape at intervals of y1.
[0039]
The hardness of the outer skin 52 of the original soft portion 47 is higher than the hardness of the outer skin 50 of the tip soft portion 45, and the outer skin 51 of the hardness changing portion 46 has an intermediate hardness. In the second embodiment, the outer shells 50, 51, and 52 have three-stage hardness changes, but a configuration in which the hardness of the outer shell 51 is increased steplessly is also conceivable. Other configurations are the same as those in the first embodiment.
[0040]
As shown in FIG. 8A, in a state where the operating rod 37 is not pulled, the tip soft part 45 is soft and the original soft part 47 is harder than that. The hardness changing portion 46 has an intermediate hardness. Here, when the operating rod 37 is pulled toward the hand side and a compressive force is applied to the coil 34, the pre-soft part 45, the hardness changing part 46, and the original soft part 47 are respectively the same as in the first embodiment. Compressed in the state shown in FIGS. 8B, 8 C, and 8 D, the gap between the cylindrical belt members 28 becomes y 2, y 3, and y 4. The pre-soft portion 45 has a large compression amount because the hardness of the outer skin 50 is low. Since the hardness of the outer skin 52 is high, the original soft part 47 has a small amount of compression. The hardness changing portion 46 is an intermediate compression amount between the pre-soft portion 45 and the original soft portion 47. That is, the gaps y2, y3, and y4 of the cylindrical band members 28 of the pre-soft portion 45, the hardness changing portion 46, and the original soft portion 47 have a relationship of y2 <y3 <y4.
[0041]
Therefore, in the state where the operating rod 37 is pulled, the tip soft portion 45 is slightly curved and the cylindrical belt members 28 come into contact with each other and are difficult to bend. However, even if the original soft portion 47 is curved, the cylindrical belt member There is a certain amount of room until the two 28's come into contact with each other. The difficulty in bending of the hardness changing portion 46 is intermediate between the tip soft portion 45 and the original soft portion 47. In other words, when the operating rod 37 is pulled, the portion that is soft before pulling the flexible tube 27 has a sufficiently large bending resistance, but the portion that is hard before pulling the flexible tube 27 does not have a large bending resistance. It has become.
[0042]
In the second form, in addition to the effect of the first form, the following effect is obtained. That is, even in a state where the operating rod 37 is not pulled, the original soft portion 47 is not easily bent, so that the insertion property is better than that of the first embodiment. Furthermore, even if the operating rod 37 is pulled, the original soft portion 47 does not become too hard, so that the insertion portion 2 becomes too hard and the patient's discomfort does not increase. On the other hand, since the pre-soft part 45 and the hardness changing part 46 are sufficiently hard and difficult to bend as a whole, insertion into a lumen far from the anus such as the transverse colon and the descending colon is more effective than the state in which the wire 36 is not pulled. Is greatly improved.
[0043]
If the gap y1 of the cylindrical belt member 28 shown in FIG. 8 (a) is set to be small only by the original soft portion 47, the bending resistance of the original soft portion 47 is further increased and the effect of preventing deflection is further increased. Insertability can be improved.
[0044]
Next, a third embodiment of the present invention will be described. FIG. 9 relates to a third embodiment of the present invention, and is an explanatory view showing a change in the gap of the cylindrical belt-like member.
[0045]
In the third embodiment, the configuration of the innermost cylindrical belt member of the tip soft portion 45, the hardness changing portion 46, and the former soft portion 47 is slightly changed from the second embodiment. That is, as shown in FIGS. 9 (a), (b), and (c), the tip soft part 45, the hardness changing part 46, and the former soft part 47 have the outer skin 50 and the mesh tube 29 as in the first embodiment. It is shared and has cylindrical belt members 53, 54, and 55, respectively, in the innermost layer. The cylindrical belt members 53, 54, and 55 are formed by winding a belt-like elastic metal in a cylindrical spiral shape with gaps y5, y6, and y7, respectively. The relationship between the sizes of the gaps is y5>y6> y7.
[0046]
In the third mode, in the state where the operating rod 37 is not pulled, since the gap between the cylindrical band member 53 is larger than the cylindrical band member 55 of the original flexible part 47, bending resistance is generated even if the tip flexible section 45 is slightly curved. Cheap. On the contrary, the former soft part 47 has a large margin until bending resistance is generated. The hardness changing portion 46 is an intermediate bending resistance.
[0047]
When the operating rod 37 is pulled toward the hand side and a compression force is applied to the coil 34, the tip soft portion 45, the hardness changing portion 46, and the original soft portion 47 are respectively shown in FIG. ), (E), and (f). The gaps between the cylindrical belt members 53, 54 and 55 after towing are y8, y9 and y10, respectively, which are shorter than before towing. In this case, since the outer skin 50 has the same hardness, the cylindrical belt members 53, 54, and 55 are shortened to substantially the same extent by the compressive force. Therefore, the relationship between the sizes of y8, y9, and y10 is y8>y9> y10.
[0048]
In the state where the operating rod 37 is pulled, if the tip soft portion 45 is slightly bent, the cylindrical belt members 53 come into contact with each other and are difficult to bend. However, the original soft portion 47 can be bent even more slightly. The members 55 come into contact with each other. The hardness change portion 46 is abutted between the cylindrical belt members 54 by an intermediate curve. That is, when the operating rod 37 is pulled, the flexible tube 27 becomes hard as a whole while maintaining the magnitude relationship of the hardness before towing.
[0049]
The third embodiment has the following effects in addition to the effects of the first embodiment. That is, even when the operation rod 37 is not pulled, the original soft portion 47 is not easily bent, and the tip soft portion 45 is flexible. Therefore, in a situation where the operating rod 37 is not pulled, the insertability is better than that of the first embodiment. Further, even after the operating rod 37 is pulled, the distal end side is soft and the proximal side is hard, while maintaining the balance of hardness suitable for insertion, it becomes harder to bend than before pulling the wire, so as in the transverse colon and descending colon. Insertability into the lumen far from the anus is further improved than in the second configuration.
[0050]
[Appendix]
(Additional item 1)
A flexible tube having at least a cylindrical belt member spirally wound with a gap and a flexible outer skin member is provided in the insertion portion, and a coil extending in the longitudinal axis direction in the flexible tube; In an endoscope in which a wire inserted therethrough is applied and a tension is applied to the wire to apply a compressive force to the coil to increase the bending hardness of the flexible tube, the wire is connected to the distal end of the flexible tube. The cylindrical belt is stretched between a fixing member provided on the flexible tube and a pulling member provided on the proximal end side of the flexible tube to apply tension to the wire, and when the wire is pulled to apply tension. An endoscope characterized by reducing a gap between members.
[0051]
(Appendix 2)
The endoscope according to claim 1, wherein at least a part of the outer skin member has a hardness higher than that of the other part.
[0052]
(Appendix 3)
The endoscope according to claim 2, wherein the cylindrical belt member positioned in a portion where the hardness of the outer skin member is higher than that of the other portion has a smaller gap than the other portion.
[0053]
(Appendix 4)
The endoscope according to claim 1, wherein the outer skin member has substantially the same hardness over its entire length, and the cylindrical belt member has at least a part of a gap smaller than another gap. .
[0054]
(Function)
In the endoscope of Additional Item 1, when the wire is pulled, a compressive force is applied to the coil to increase resistance to bending, and the gap between the cylindrical belt members is reduced by elastic deformation. When the gap between the cylindrical band members is reduced, the band members come into contact with each other even if the flexible tube is bent a little, and a large bending resistance is generated even if it is further bent. That is, at the same time as the hardness of the coil increases, the hardness of the flexible tube itself also increases.
[0055]
In addition to the action of the endoscope according to supplementary item 1, the endoscope of supplementary items 2 and 3 is more difficult to compress the flexible tube at the portion where the hardness of the outer skin member is high compared to the portion where it is low. Therefore, in the portion where the hardness of the outer skin member is high, even if the wire is pulled, the gap between the cylindrical belt members is not so small, and the action of increasing the bending resistance is suppressed by reducing the gap.
[0056]
In addition to the action of the endoscope of Additional Item 1, the endoscope of Additional Item 4 has the same overall hardness as the outer skin member, so that the cylindrical belt member is compressed as a whole. Accordingly, the size relationship of the gap between the cylindrical belt members existing before the wire is pulled does not change even after the wire is pulled.
[0057]
(effect)
In the endoscope of the supplementary item 1, since the flexible tube itself is hardened in addition to the coil, the entire insertion portion is sufficient even if the hardness of the coil alone is insufficient due to restrictions of other built-in items. Change in hardness is possible, and insertability is improved.
[0058]
In addition to the effect of the endoscope of appendix 1, the endoscope of appendix 2 is partially improved in insertability, such as preventing bending even when the wire is not pulled, by partially increasing the hardness of the outer skin member. Can be planned. When the wire is pulled, the portion where the hardness of the outer skin member is increased does not become too hard, so that the discomfort of the patient inserting the endoscope is not increased. Since the bending resistance sufficiently increases in the portion other than the case where the hardness of the outer skin member is increased, it becomes difficult to bend as a whole, and the insertion property is further improved as compared with the state where the wire is not pulled.
[0059]
In addition to the effect of the endoscope of appendix item 2, the endoscope of appendix item 3 is more difficult to bend in the portion where the hardness of the outer skin member is higher than that of the endoscope of appendix item 2. Improvement can be expected.
[0060]
In addition to the effect of the endoscope of appendix 1, the endoscope of appendix 4 increases the overall bending resistance while maintaining the balance of hardness suitable for insertion when the wire is pulled. The insertability is even better than that of the third endoscope.
[0061]
【The invention's effect】
As described above, according to the present invention, since the flexible tube itself is hardened in addition to the coil, even if the hardness change with the coil alone is insufficient due to restrictions of other built-in items, the entire insertion portion Can sufficiently change the hardness, and can provide excellent effects such as improved insertability.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing the structure of an endoscope according to a first embodiment of the present invention.
FIG. 2 is an explanatory diagram showing coil compression by wire pulling
FIG. 3 is an explanatory view showing the state of deformation of the flexible tube by wire pulling
FIG. 4 is an explanatory view showing a deformed state of the cylindrical belt member when the flexible tube is bent.
FIG. 5 is an explanatory view showing a modification of the hardness adjusting mechanism.
FIG. 6 is an explanatory view showing another modified example of the hardness adjusting mechanism.
FIG. 7 is an explanatory diagram showing a configuration of a flexible portion according to a second embodiment of the present invention.
FIG. 8 is an explanatory view showing a change in the gap of the cylindrical belt member as above.
FIG. 9 is an explanatory diagram related to a third embodiment of the present invention and showing a change in a gap of a cylindrical belt-shaped member.
[Explanation of symbols]
1 Endoscope
2 Insertion part
19 Connection pipe
27 Flexible tube
28 Cylindrical strip member
30 skin
34 coils
36 wires
37 Operation stick

Claims

A flexible tube having at least a cylindrical belt member spirally wound with a gap and a flexible outer skin member is provided in the insertion portion, and a coil extending in the longitudinal axis direction in the flexible tube; In an endoscope that provides a wire inserted therethrough and increases the bending hardness of the flexible tube by applying a compressive force to the coil by applying tension to the wire,
The outer skin member is configured to have substantially the same hardness over its entire length, and the cylindrical belt member is configured such that at least some of the gaps are smaller than other gaps,
The wire is stretched between a fixing member provided at a distal end of the flexible tube and a pulling member provided on a proximal end side of the flexible tube to apply tension to the wire, and the wire is pulled An endoscope, wherein a gap between the cylindrical belt members is reduced when tension is applied.