US20120238952A1

US20120238952A1 - Endoluminal surgical tool with small bend radius steering section

Info

Publication number: US20120238952A1
Application number: US13/483,371
Authority: US
Inventors: Sean Mitchell; Richard C. Ewers; Tracy D. Maahs
Original assignee: USGI Medical Inc
Current assignee: USGI Medical Inc
Priority date: 2008-04-02
Filing date: 2012-05-30
Publication date: 2012-09-20
Also published as: US20140107570A1; US20150173589A1; US9504371B2

Abstract

An endoluminal surgical instrument has first and second steering controls on a handle. A flexible shaft attached to the handle has a distal steerable end including a first link and a second link separated by a plurality of intermediate links. First and second steering elements, such as pairs of steering wires, are linked to first and second steering controls and to the first and, second links. One or more of the links is pivotable through an angle of at least 30 degrees relative to an adjoining link. The set back position of the second steering elements from the first steering elements, and the pivoting capability of the links allows the steerable end to be steered into a small bend radius. This makes the instrument highly maneuverable for use in endoluminal surgery, such as incision-less surgery of the stomach.

Description

PRIORITY CLAIM

This Application is a Continuation-in-Part of U.S. patent application No. 12/061,591, filed Apr. 2, 2008, now pending and incorporated herein by reference.

BACKGROUND

Various endoscopic systems have been successfully used to perform a wide variety of diagnostic and surgical procedures. Most of these types of systems having a steering capability. Specifically, the leading or distal end of the endoscopic surgical instrument can be introduced into the body, for example into the stomach via the throat, with the physician then steering the tip of instrument. The steering is typically achieved via four steering wires attached to wheels, levers, or other actuators on the handle of the instrument, which remains outside of the body. By manipulating the actuators, the physician can steer the tip of the instrument in the up/down and left/right directions. This allows the physician to position surgical tools as desired.
In order to provide the most steering flexibility, the distal end of the instrument advantageously can bend into a tight radius, via control of the actuators on the handle. However, the bending radius is limited by certain factors. One factor is that the pivoting links that make up the skeleton or frame of the instrument can only pivot to limited angle relative to each other. Another factor is that the left/right and up/down steering movements are not entirely independent. Specifically, when the distal end of the instrument is steering to it maximum left or right steering position, the ability to also steer in the up or down direction becomes very limited, and vice versa. As a result, operating the instrument to position the instrument tip as desired can become difficult.
Accordingly, engineering challenges remain in designing endosurgical systems allow for highly flexible positioning options.

SUMMARY

In a first aspect, an endoluminal surgical instrument has first and second steering controls on a handle. A flexible shaft attached to the handle has a distal steerable end including a first link and a second link separated by a plurality of intermediate links. First and second steering elements, such as pairs of steering wires, are linked to first and second steering controls and to the first and second links. One or more of the links is pivotable through an angle of at least 30 degrees relative to an adjoining link. The set back position of the second steering elements and the pivoting capability of the links allows the steerable end to be steered into a small bend radius. This makes the instrument highly maneuverable for use in endoluminal surgery, such as incision-less surgery of the stomach.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a back, top, and right side perspective view of an endoscopic system.

FIG. 2 is a front, top, and left side perspective view of the shapelock assembly shown in FIG. 1.

FIG. 3 is a schematically illustrated side view of the distal end of the endoscopic system shown in FIG. 1.

FIG. 4 is an enlarged schematically illustrated side view of the tip of the instrument shown in FIG. 3.

FIG. 5 is a schematically illustrated section views taken along line 5-5 of FIG. 3.

FIGS. 6 and 7 are cross-sectional views of the endoscopic system of FIGS. 1-5.

FIG. 8 is a side view of the distal end of a tight bend radius instrument, with the sheath or outer covering removed for purpose of illustration.

FIG. 9 is a side view of the instrument shown in FIG. 8 steered into a near maximum up position.

DETAILED DESCRIPTION OF THE DRAWINGS

Turning to the drawings, as shown in FIGS. 1 and 2, an endoscopic system 30 includes a reusable shapelock assembly 34 that is adapted for use within a disposable assembly generally designated 32. The disposable assembly 32 has a flexible sheath 38 attached to a relatively rigid handle 36.
The sheath 38 includes a tip 58 attached to the distal end of a steerable section 42. A body section 40 of the sheath 38 extends proximally from the steerable section 42 to the handle 36. A lock nut or similar attachment holds the proximal end of the body section 40 of the sheath 38 onto the handle 36.
Referring to FIGS. 3 and 4, the sheath tip 58 has one or more tool lumen openings 60. A plurality of tool lumens extend through the interior of the sheath 38. The tool lumens are defined by one or more structural guideway members provided within the interior of the sheath 38. In the embodiments shown, the tool lumens are defined by a plurality of sleeves or tubes 44 and 46, each having an open distal end that is sealed around a respective lumen opening 60 in the tip 58. The tubes 44 and 46 extend back from the tip 58 through the length of the sheath 38 to the handle 36. The tubes may be flexible rubber or plastic tubes that act as guideways between the handle 36 and the tip 58 for tools and instruments. The tubes may alternatively be flexible tubes having a composite construction, such as a multi-layer extrusion, or coil and/or braid reinforced construction. The tubes may be constructed to reduce or eliminate the likelihood that the tubes will become twisted, kinked, tangled, torn, or to prevent the lumens of the tubes from collapsing under vacuum.
Referring still to FIGS. 3 and 4, the steerable section 42 at the distal end of the sheath 38 may be formed by segments, links, or other generally rigid and pivotably interconnected elements. In the example shown, the steerable section 42 includes links, with the first link shown at 74 and the second link at 76. The length and flexibility of the steerable section 42 is varied by selecting the number and size of the individual links making up the steerable section 42.
As shown in FIG. 8, a first pair of steering wires 80A or other steering elements are attached onto opposite sides of the first link 74 at attachment points 83. Generally the first link 74 is the front or leading link which the tip 58 attached to. A second pair of steering wires 80B are attached to opposite sides of a second or proximal link 75 at attachment points 81. The proximal link 75 is spaced 4-30, 8-24 or 12-20 cm behind the first link 74, with several intervening links 77 between the first link 74 and the proximal link, for steering the steerable section 42. The steering wires 80A and 80B extend back from the first link 74 and the proximal link 75 and subsequent proximal links of the steering section 42, through the sheath 38 to the handle 36.
Alternatively, the subsequent proximal links, i.e., links between the handle and the proximal link 75 may be omitted and replaced with a tubular structure not having any links. The links are pivotally attached to each, with alternating angular positions, i.e., with even links pivotable in the up/down direction and with odd links pivotable in the left/right direction. The links are designed to allow at least 30, 35, 40, 45, or more degrees of pivot movement or angular rotation between adjoining links. The attachment of the second steering wires 80B onto the proximal link spaced behind the first link 74, and the pivoting capability of the links, allows the steerable end to be steered into a small bend radius. This makes the instrument highly maneuverable for use in endoluminal surgery.
The steering wires may be provided within coils 82 or other column strength element. The coils 82, if used, allow the steering wires to be tensioned without buckling the sheath 38. The steering section may be about 4-10 cm long, whereas the sheath 38 is typically between 20-200 cm.
Referring to FIGS. 4 and 5, the sheath 38 has an outer skin or layer 206 formed of a material such as a polymeric or plastic material that is flexible and that provides a protective layer to prevent passage ingress of bodily fluids. The cylindrical proximal end 72 of the tip 58 is sealed onto the outer skin 206 via an adhesive or other bonding or attachment method. The tip 58 may be removably attached to the distal end of the sheath 38, such as by screwing, friction fit, or other mechanism adapted to provide the user with the ability to exchange tips for various procedures. The tip 58 may be made of hard or soft plastic or rubber, or similar non-porous materials. As the sleeves or tubes 44, 46 are sealed at the lumen openings 60 of the tip 58, gases and liquids encountered during use of the system 30 within the body are substantially prevented from entering into the sheath 38, except through the tubes.
As shown in FIG. 5, passageways 212 for the steering wires may be provided within the walls Of the sheath 38. Each passageway 212 may be located within the skin material, between first and second layers of braid or reinforcement material. The passageways 212 may be formed in straight or spiral, radially spaced alignment extending over the length of the sheath 38.
FIG. 2 shows a locking handle 172 that opens at its distal end. The shape lock body 150 is formed by segments, such as links that are pivotably attached to (or positioned next to) each other in a nested arrangement. The links may be formed as nested rings, so that the shapelock body 150 is tubular, or has an open internal through passageway.
Referring to FIG. 3, at position 180, the steering wires 80A exit from the passageways 212, run inside of the steerable section 42, and attach to the first link 74 of the steerable section 42. The other pair of steering wires 80B attach to the proximal link 75 spaced proximally apart from the first link.
Toward the proximal end of the sheath 38, the steering wires are contained within the passageways 212 and extend to the handle 36, where the steering wires 80 are operably connected to the control knobs 140 and 144. Consequently, the shape lock 34 may be inserted into the central sheath opening 220 without contacting or interfering with the steering wires.
Turning to FIGS. 6 and 7, cross-section views of the endoscopic system 32 shown in FIG. 1. The sheath 38 may have a composite construction, including an outer layer 322, a body member 324, and an inner layer 326. The composite construction provides the shaft with improved strength, flexibility, and torque transmission capability over conventional endoscopic shaft constructions. The outer layer 322 and inner layer 326 may each include one, two, three, or more layers of a braided or woven mesh reinforcement material, such as polyethylene terephthalate (PET), nylon, metal or metallic fibers, or other suitable reinforcement material. The braided or woven mesh reinforcement layers are preferably porous, thereby providing the ability for a bonding material to penetrate the reinforcement layers.
FIGS. 6 and 7 also show the tubes 44 and 46, as well as two additional tubes 48 and 50, which may optionally also be included within the sheath 38. If used, the tubes 44 and 46 may be larger diameter tubes having an ID of about 3 mm to about 9 mm, preferably about 6.3 mm, with tubes 48 and 50 having a smaller diameter tubes, with an ID of about 1.5 mm to about 7 mm, preferably about 4 mm. The outer diameter of the sheath 38 may preferably be in the range of about 10 mm to about 30 mm. The steering wires 80 extend from the steering controls 140 and 144 on the handle 36 through the sheath 38 to the distal end of the shaft at links 74 and 75. The steering wire coils 82, if used, receive and retain the steering wires 80. The steering wire coils 82 may be formed integrally with or embedded in the sheath structure. Alternatively, the steering wire coils 82, along with the tubes 44-50, may float within the inner lumen 220.
Thus, novel methods and apparatus have been shown and described. Various changes and substitutions may of course be made without departing from the spirit and scope of the invention. The invention, therefore, should not be limited except by the following claims, and their equivalents.

Claims

1. An endoluminal surgical instrument, comprising:

a handle;

first and second steering controls on the handle;

a flexible shaft attached to the handle;

the flexible shaft having a distal steerable end including a first link and a second link separated by a plurality of intermediate links; and

first and second pairs of steering wires attached respectively to the first and second steering controls and the first and second links.

2. The system of claim 1 further comprising an end tip on a distal end of the flexible shaft and with first link adjacent to the end tip.

3. The system of claim 2 with the end tip attached onto the first link.

4. The system of claim 1 comprising 2-10 intermediate links.

5. The system of claim 1 with the steerable end having a length L and with the first and second links separated by a dimension equal to 0.3 L to 0.7 L.

6. The system of claim 1 with the first pair of steering wires angularly offset from the second pair of steering wires by 80-110 degrees.

7. The system of claim 6 with the steering wires angularly spaced apart equally.

8. The system of claim 1 with the first, second and intermediate links substantially the same.

9. The system of claim 1 with one or more of the links pivotal through an angle of at least 30 degrees relative to an adjoining pivotally attached link.

10. The system of claim 1 with one or more of the links pivotal through an angle of at least 40 degrees relative to an adjoining pivotally attached link.

11. The system of claim 1 with each of the links pivotal through an angle of at least 30 degrees relative to an adjoining pivotally attached link.

12. An endoluminal surgical instrument, comprising:

a handle;

left/right and up/down steering controls on the handle;

a flexible shaft, with a proximal end of the flexible shaft attached to the handle;

left and right steering wires extending from the left/right steering control to the first link, with the left steering wire attached to a left side of the first link and with the right steering wire attached to a right side of the first link; and

up and down steering wires extending from the up/down steering control to the second link, with the up steering wire attached to a top of the second link and with the down steering wire attached to a bottom of the second link.