Snare for endoscope

• US 6,224,611 B1
• Filed: 08/31/1999
• Issued: 05/01/2001
• Est. Priority Date: 09/14/1998
• Status: Expired due to Fees

• Current Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Original Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
• Inventors: Ouchi, Teruo
• Primary Examiner(s): Wilson, John J.
• Assistant Examiner(s): Robert, Eduardo C.
• Application Number:
  US09/386,485
• Time in Patent Office: 609 Days
• Field of Search: 606/113, 606/79
• US Class Current: 606/113
• CPC Class Codes: A61B 17/32056 Surgical snare instruments for removing or smashing calculi A61B2017/2212; tonsillotomes A61B17/26
• CPC Class Codes: A61B 18/14 Probes or electrodes therefor
• CPC Class Codes: A61B 2018/1407 Loop

Abstract

A snare for an endoscope includes a control wire axially movably inserted in a flexible sheath. A snare loop formed by an elastic wire is connected to the distal end of the control wire. When the control wire is advanced, the snare loop projects from the distal end of the sheath and expands in a loop shape by its own elasticity. When the control wire is retracted, the snare loop is pulled into the sheath and folded. The snare loop is formed by two elastic wires between two mutually secured portions of the elastic wires, which are laid in parallel and in close contact with each other and secured together directly at two longitudinally spaced positions. The control wire is formed by an extending portion of at least one of the elastic wires that extends rearward from the mutually secured portion at the rear end of the snare loop.

Claims

1. A snare for an endoscope comprising an axially movable control wire extending within a flexible sheath and a snare loop, said snare loop connected to a distal end of said control wire, wherein when said control wire is axially advanced, said snare loop projects from a distal end of said flexible sheath and expands into a loop shape due to elasticity of said snare loop, whereas when said control wire is axially retracted, said snare loop retracts into the distal end of said flexible sheath and is folded into a closed shape;

said snare loop comprising two elastic wires extending between two mutually secured portions, said two elastic wires extending parallel to each other and at least partially in close contact with each other, said two elastic wires being secured directly together at two positions longitudinally spaced from each other, each of said two mutually secured portions having an outer diameter not larger than a total of the diameters of said two elastic wires; and

said control wire comprising a portion of at least one of said two elastic wires that extends rearwardly from the one of said two mutually secured portions that is positioned at a rear end of said snare loop.

2. A snare for an endoscope according to claim 1, said two elastic wires being secured together at said two mutually secured portions by one of silver-alloy brazing, laser beam welding, and plasma arc welding.

3. The snare for an endoscope according to claim 1, said snare loop, when projecting from said distal end of said flexible sheath, having a shape of a polygon.

4. A snare for an endoscope according to claim 1, straight portions being formed between a loop portion of said snare loop and at least one of said two mutually secured portion, respectively.

5. A snare for an endoscope according to claim 1, wherein each of said two elastic wires extend rearward from the mutually secured portion at the rear end of said snare loop to form said control wire.

6. A snare for an endoscope according to claim 1, said two elastic wires also being secured together while axially extending in parallel and in close contact with each other at at least one intermediate portion of said control wire.

7. A snare for an endoscope according to claim 1, said elastic wires comprising electrically conductive wires, a high-frequency electric current being suppliable to said snare loop through said control wire.

8. A snare for an endoscope according to claim 1, wherein said two elastic wires are secured together at said two mutually secured portions by one of silver-alloy brazing, laser beam welding, and plasma arc welding.

9. A snare for an endoscope comprising an axially movable control wire extending within a flexible sheath and a snare loop, said snare loop connected to a distal end of said control wire, wherein when said control wire is axially advanced, said snare loop projects from a distal end of said flexible sheath and expands into a loop shape due to elasticity of said snare loop, whereas when said control wire is axially retracted, said snare loop retracts into the distal end of said flexible sheath and is folded into a closed shape;

said snare loop comprising two elastic wires extending between two mutually secured portions, said two elastic wires extending parallel to each other and at least partially in close contact with each other, said two elastic wires being secured together at two positions longitudinally spaced from each other, both said elastic wires extending rearwardly from the mutually secured portion at a rear end of said snare loop to form said control wire.

10. A snare for an endoscope according to claim 9, wherein each of said two mutually secured portions has an outer diameter not larger than a total of the diameters of said two elastic wires.

11. A snare for an endoscope according to claim 10, wherein said two elastic wires are secured together at said two mutually secured portions by one of silver-alloy brazing, laser beam welding, and plasma arc welding.

12. A snare for an endoscope according to claim 9, said elastic wires comprising electrically conductive wires, a high-frequency electric current being suppliable to said snare loop through said control wire.

13. The snare for an endoscope according to claim 9, said two elastic wires being secured directly to each other at said two positions longitudinally spaced from each other.

14. The snare for an endoscope according to claim 9, sid snare loop, when projecting from said distal end of said flexible sheath, having a shape of a polygon.

15. A snare for an endoscope comprising an axially movable control wire extending within a flexible sheath, and a snare loop, said snare loop connected to a distal end of said control wire, wherein when said control wire is axially advanced, said snare loop projects from a distal end of said flexible sheath and expands into a loop shape due to elasticity of said snare loop, whereas when said control wire is axially retracted, said snare loop retracts into the distal end of said flexible sheath and is folded into a closed shape;

said snare loop comprising two elastic wires extending between two mutually secured portions, said two elastic wires extending parallel to each other and at least partially in close contact with each other, said two elastic wires being secured together at two positions longitudinally spaced from each other, said two elastic wires also being secured together while extending axially in parallel and in close contact with each other at at least one intermediate portion of said control wire; and

said control wire comprising a portion of at least one of said two elastic wires that extends rearwardly from the one of said two mutually secured portions that is positioned at a rear end of said snare loop.

16. A snare for an endoscope according to claim 15, said elastic wires comprising electrically conductive wires, a high-frequency electric current being suppliable to said snare loop through said control wire.

17. The snare for an endoscope according to claim 16, said two elastic wires being secured directly to each other at said two positions longitudinally spaced from each other.

18. The snare for an endoscope according to claim 16, said snare loop, when projecting from said distal end of said flexible sheath, having a shape of a polygon.