초록 ▼

Apparatus and methods are provided for placing and advancing a diagnostic or therapeutic instrument in a hollow body organ of a tortuous or unsupported anatomy, comprising a handle, an overtube disposed within a hydrophilic sheath, and a distal region having an atraumatic tip. The overtube may be re

Apparatus and methods are provided for placing and advancing a diagnostic or therapeutic instrument in a hollow body organ of a tortuous or unsupported anatomy, comprising a handle, an overtube disposed within a hydrophilic sheath, and a distal region having an atraumatic tip. The overtube may be removable from the handle, and have a longitudinal axis disposed at an angle relative to the handle. The sheath may be disposable to permit reuse of the overtube. Fail-safe tensioning mechanisms may be provided to selectively stiffen the overtube to reduce distension of the organ caused by advancement of the diagnostic or therapeutic instrument. The fail-safe tensioning mechanisms reduce the risk of reconfiguration of the overtube in the event that the tension system fails, and, in one embodiment, rigidizes the overtube without substantial proximal movement of the distal region. The distal region permits passive steering of the overtube caused by deflection of the diagnostic or therapeutic instrument, while the atraumatic tip prevents the wall of the organ from becoming caught or pinched during manipulation of the diagnostic or therapeutic instrument.

대표청구항 ▼

1. Apparatus for advancing a first diagnostic or therapeutic instrument into a hollow body organ of unsupported anatomy, the apparatus comprising:a handle; an overtube coupled to the handle, the overtube having proximal and distal ends, an exterior surface, an interior surface that defines a lumen e

1. Apparatus for advancing a first diagnostic or therapeutic instrument into a hollow body organ of unsupported anatomy, the apparatus comprising:a handle; an overtube coupled to the handle, the overtube having proximal and distal ends, an exterior surface, an interior surface that defines a lumen extending between the proximal and distal ends to permit passage of the first diagnostic or therapeutic instrument, a flexible state that facilitates insertion of the overtube into a hollow body organ, and a rigid state wherein the overtube resists bending forces exerted on the interior surface during insertion or withdrawal of the first diagnostic or therapeutic instrument through the lumen; and a tensioning system selectively operable to transition the overtube between the flexible and rigid states, the tensioning system having a fail-safe mode that reduces the risk of undesired reconfiguration of the overtube in the event of tensioning system failure. 2. The apparatus of claim 1, further comprising a disposable sheath having a first portion that extends through the lumen to provide a barrier between the interior surface and the first diagnostic or therapeutic instrument and a second portion that extends over the exterior surface.3. The apparatus of claim 2, wherein the disposable sheath comprises a hydrophilic material.4. The apparatus of claim 2, wherein the disposable sheath comprises a non-kinking coil.5. The apparatus of claim 2, wherein the first portion comprises a thin, flexible material.6. The apparatus of claim 1, wherein the overtube comprises a plurality of nestable links that each has a lateral wall.7. The apparatus of claim 6, wherein the plurality of nestable links are made from a material selected from the group consisting of polymers, metals and combinations thereof.8. The apparatus of claim 7, wherein the polymer is filled with glass fiber, carbon fiber, or combinations thereof.9. The apparatus of claim 8, wherein the polymer is polyurethane.10. The apparatus of claim 6, wherein each one of the plurality of nestable links comprises a distal surface and a proximal surface.11. The apparatus of claim 10, wherein the distal surface is macroscopically textured, and the proximal surface comprises teeth configured to engage the distal surface.12. The apparatus of claim 11, wherein each one of the plurality of nestable links further comprises one or more springs that prevent coaction between the distal and proximal surfaces of adjacent ones of the plurality of nestable links, absent an externally applied force.13. The apparatus of claim 11, further comprising a plurality of elastomeric discs, wherein each one of the plurality of elastomeric discs is disposed between adjacent ones of the plurality of nestable links.14. The apparatus of claim 10, wherein each one of the plurality of nestable links further comprises a proximal edge and a band circumferentially disposed around the distal surface adjacent to the proximal edge.15. The apparatus of claim 10, wherein a radius of curvature of the proximal surface closely approximates a radius of curvature of the distal surface.16. The apparatus of claim 10, wherein a coefficient of static friction between the distal and proximal surfaces are within a range of about 0.2 to 1.4, inclusive.17. The apparatus of claim 6, further comprising:a plurality of tension wire bores extending through the lateral wall of each one of the plurality of nestable links; and at least one tension wire translatably disposed through one or more of the plurality of tension wire bores. 18. The apparatus of claim 17, wherein the at least one tension wire has a first diameter and each one of the plurality of tension wire bores has a second diameter, and the ratio of the first diameter to the second diameter is in a range of approximately ½ to ⅔.19. The apparatus of claim 6, wherein each one of the plurality of nestable links comprises an integral lubricious liner.20. The apparatus of claim 6, wherein the overtube increases in axial length by less than or equal to approximately 0.31 inch when one of the plurality of nestable links is nested within another one of the plurality of nestable links.21. The apparatus of claim 6, wherein the tensioning system comprises a plurality of tension wires that thread the plurality of nested links together.22. The apparatus of claim 21, wherein the tensioning system is configured so that tension within each one of the plurality of tension wires is dependent on tension within the remaining plurality of tension wires.23. The apparatus of claim 21, wherein the tensioning system comprises a pulley manifold.24. The apparatus of claim 23, wherein the pulley manifold further comprises a plurality of grooves within which the plurality of wires are slidably disposed.25. The apparatus of claim 24, wherein the plurality of grooves are disposed on a lateral surface of the pulley manifold.26. The apparatus of claim 24, wherein the plurality of grooves are disposed on a proximal surface of the pulley manifold.27. The apparatus of claim 23, wherein the pulley manifold is affixed within the handle.28. The apparatus of claim 21, wherein the plurality of tension wires comprises at least one length of wire.29. The apparatus of claim 21, wherein the plurality of tension wires comprises a shape memory material.30. The apparatus of claim 21, wherein the plurality of tension wires comprises a superelastic material.31. The apparatus of claim 1, wherein the tensioning system further comprises a piston.32. The apparatus of claim 1, wherein the tensioning system comprises a spring.33. The apparatus of claim 1, wherein the tensioning system comprises a damper.34. The apparatus of claim 1, wherein the tensioning system is selectively operable to transition the overtube between the flexible and rigid states without substantial proximal movement of the distal end of the overtube.35. The apparatus of claim 34, wherein the tensioning system is configured to apply a distally-directed clamping load to the overtube.36. The apparatus of claim 6, wherein the tensioning system further comprises a plurality of nestable bridge links interposed between a predetermined number of the plurality of nestable links, and a plurality of ribbons, wherein each one of the plurality of ribbons is coupled to adjacent ones of the plurality of nestable bridge links.37. The apparatus of claim 36, wherein the plurality of ribbons comprises a shape memory material.38. The apparatus of claim 1, wherein the tensioning system is configured to transition the overtube from the flexible state to the rigid state with a single actuation of the tensioning system.39. The apparatus of claim 1, wherein the tensioning system is configured to transition the overtube between the flexible and rigid states with successive actuations of the tensioning system.40. The apparatus of claim 1, wherein the handle further comprises an extension suitable for insertion into the hollow body organ.41. The apparatus of claim 1, wherein the handle has a length less than or equal to approximately 5 inches.42. The apparatus of claim 1, wherein the handle comprises an indicator that provides information about the rigidity of the overtube.43. The apparatus of claim 1, wherein a thickness of the overtube is less than or equal to approximately 1 mm.44. The apparatus of claim 1, further comprising a strap configured to releasably couple the handle of the apparatus to a proximal end of the first diagnostic or therapeutic instrument.45. The apparatus of claim 1, wherein the handle further comprises a shield that prevents a proximal portion of the handle from being inadvertently inserted into the hollow body organ.