Shaft Constructions for Medical Devices with an Articulating Tip
An endoscopic surgical instrument for sealing tissue includes an end effector having a pair of jaw members adapted to connect to a source of electrosurgical energy. At least one jaw member is movable relative to the other between an open configuration and a closed configuration for grasping tissue. A handle is movable to induce motion in the end effector between the open and closed configurations. An elongated shaft defines a longitudinal axis and is coupled between the end effector and the handle. The shaft includes a plurality of links arranged such that neighboring links engage one another across a pair of edges to maintain the end effector in an aligned configuration with respect to the longitudinal axis. Each of the edges is spaced laterally from the longitudinal axis. The neighboring links may pivot about the rotational edges to move the end effector to an articulated configuration.
1 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a plurality of links arranged sequentially such that neighboring links engage one another across a pair of rotational edges defined by each of the links to maintain the end effector in an aligned configuration with respect to the longitudinal axis, wherein each of the rotational edges is substantially spaced in a lateral direction from the longitudinal axis and wherein the neighboring links may pivot about the rotational edges to move the end effector to an articulated configuration.
2 . The instrument according to claim 1 , further comprising a pair of substantially elastic steering cables extending through at least one longitudinal cavity defined in the elongated shaft, the pair of steering cables coupled to a distal portion of the elongated shaft such that a differential tension in the pair of steering cables induces pivotal motion about the rotational edges to articulate the end effector in a first plane of articulation.
3 . The instrument according to claim 2 , wherein a general tension is imparted to the pair of steering cables when the end effector is in the aligned configuration.
4 . The instrument according to claim 2 , wherein the pair of rotational edges defined by one of the links is radially offset from the pair of rotational edges defined by another of the plurality of links by about 90° to define a second plane of articulation that is substantially orthogonal to the first plane of articulation.
5 . The instrument according to claim 4 , further comprising a second pair of steering cables extending through the least one longitudinal cavity and coupled to a distal portion of the elongated shaft such that a differential tension in the second pair of steering cables induces pivotal motion about the rotational edges to articulate the end effector in the second plane of articulation.
6 . The instrument according to claim 1 , wherein a substantially flat mating surface extends between the pair of rotational edges.
7 . The instrument according to claim 1 , wherein the rotational edges are rounded.
8 . The instrument according to claim 1 , wherein at least one of the plurality of links includes a rib extending therefrom to engage a neighboring link and thereby discourage radial displacement between the neighboring links.
9 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion to permit the end effector to articulate, the flexible portion comprising:
a plurality of links arranged sequentially such that neighboring links engage one another across substantially flat forward and trailing mating faces to maintain the end effector in an aligned configuration with respect to the longitudinal axis, wherein at least one of the forward and trailing mating faces defines a rotational edge thereof about which the neighboring links may pivot to move the end effector to an articulated configuration;
at least one longitudinal cavity extending through the flexible portion of the elongated shaft; and
at least one steering cable extending through the at least one longitudinal cavity, the steering cable arranged to impart a compressive force on the plurality of links to maintain engagement between the mating faces.
10 . The instrument according to claim 9 , wherein the at least one of the forward and trailing mating faces defines a first pair of rotational edges on opposing sides of the longitudinal axis such that the end effector articulates in opposite directions in a first plane of articulation upon pivoting of the neighboring links about each of the first pair rotational edges.
11 . The instrument according to claim 10 , wherein at least one link of the plurality of links defines a second pair of rotational edges, the second pair of rotational edges oriented such that the end effector articulates in a second plane of articulation upon pivoting of neighboring links about the second first pair rotational edges, the second plane of articulation being substantially orthogonal to the first plane of articulation.
12 . The instrument according to claim 11 , wherein the at least one steering cable includes a first pair of steering cables coupled to a distal end of the elongated shaft such that relative longitudinal movement between the first pair of steering cables induces articulation of the end effector in the first plane of articulation.
13 . The instrument according to claim 12 , wherein the at least one steering cable further includes a second pair of steering cables coupled to a distal end of the elongated shaft such that relative longitudinal motion between the second pair of steering cables induces articulation of the end effector in the second plane of articulation.
14 . The instrument according to claim 11 , wherein each link of the plurality of links is similar in construction and each link is oriented with a 90° offset with respect to neighboring links to orient the pair of rotational edges.
15 . The instrument according to claim 9 , wherein at least one of the plurality of links includes a rib extending therefrom to engage a neighboring link and thereby discourage radial displacement between the neighboring links.
16 . The instrument according to claim 9 , wherein at least one steering cable is substantially elastic.
17 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a plurality of links arranged sequentially such that each of the links may pivot relative to a neighboring link to move the end effector between an aligned configuration and an articulated configuration with respect to the longitudinal axis, wherein each of the links includes a substantially rigid base and a pair of relatively flexible tubes extending therefrom to engage the neighboring link.
18 . The instrument according to claim 17 , further comprising a pair of substantially elastic steering cables extending through at least one longitudinal cavity defined in the elongated shaft, the pair of steering cables coupled to a distal portion of the elongated shaft such that a differential tension in the pair of steering cables induces elastic bending in the pair of flexible tubes to articulate the end effector in a first plane of articulation.
19 . The instrument according to claim 18 , wherein a general tension is imparted to the pair of steering cables when the end effector is in the aligned configuration.
20 . The instrument according to claim 18 , wherein the pair of flexible tubes defined by one of the links is radially offset from the pair of flexible tubes defined by another of the plurality of links by about 90° to define a second plane of articulation that is substantially orthogonal to the first plane of articulation.
21 . The instrument according to claim 20 , further comprising a second pair of steering cables extending through the least one longitudinal cavity and coupled to a distal portion of the elongated shaft such that a differential tension in the second pair of steering cables induces bending of the flexible tubes to articulate the end effector in the second plane of articulation.
22 . The instrument according to claim 20 , wherein the at least one longitudinal cavity extends through the flexible tubes.
23 . The instrument according to claim 17 , wherein the flexible tubes include a nitinol alloy.
24 . The instrument according to claim 17 , wherein at least one of the plurality of links includes a rib extending therefrom to engage a neighboring link and thereby discourage radial displacement between the neighboring links.
25 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion to permit the end effector to articulate, the flexible portion comprising:
a plurality of links wherein at least one link includes a substantially rigid base and at least one relatively flexible tube extending therefrom to engage a neighboring link and maintain the end effector in an aligned configuration with respect to the longitudinal axis;
at least one longitudinal cavity extending through the flexible tube; and
at least one steering cable extending through the at least one longitudinal cavity, the steering cable arranged to impart a compressive force on the plurality of links to induce bending in the flexible tube to move the end effector to an articulated configuration.
26 . The instrument according to claim 25 , wherein the at least one flexible tube includes a first pair of flexible tubes disposed on opposing sides of the longitudinal axis to define a first plane of articulation such that the end effector articulates in opposite directions in the first plane of articulation upon bending of the flexible tubes.
27 . The instrument according to claim 16 , wherein the neighboring link includes second pair of flexible tubes disposed on opposing sides of the longitudinal axis to define a second plane of articulation such that the end effector articulates in the second plane of articulation upon bending of the flexible tubes, the second plane of articulation being substantially orthogonal to the first plane of articulation.
28 . The instrument according to claim 27 , wherein the at least one steering cable includes a first pair of steering cables coupled to a distal end of the elongated shaft such that relative longitudinal movement between the first pair of steering cables induces articulation of the end effector in the first plane of articulation.
29 . The instrument according to claim 28 , wherein the at least one steering cable further includes a second pair of steering cables coupled to a distal end of the elongated shaft such that relative longitudinal motion between the second pair of steering cables induces articulation of the end effector in the second plane of articulation.
30 . The instrument according to claim 27 , wherein each link of the plurality of links is similar in construction and each link is oriented with a 90° offset with respect to neighboring links to orient the pair flexible tubes.
31 . The instrument according to claim 25 , wherein at least one of the plurality of links includes a rib extending therefrom to engage a neighboring link and thereby discourage radial displacement between the neighboring links.
32 . The instrument according to claim 31 , wherein the at least one link includes a proximal rib projecting from the rigid base thereof to engage a distal rib projecting from a rigid base of the neighboring link.
33 . The instrument according to claim 32 , wherein the proximal rib engages the distal rib across a substantially flat sliding face.
34 . The instrument according to claim 25 , wherein at least one steering cable is substantially elastic.
35 . The instrument according to claim 25 , wherein the at least one flexible tube includes a nitinol alloy.
36 . An endoscopic surgical instrument comprising:
an end effector including a pair of jaw members, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration;
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion movable to a non-aligned configuration with respect to the longitudinal axis, the flexible portion exhibiting a composite construction comprising:
an outer tubular layer defining a first wall thickness; and
an inner tubular layer extending axially through the outer tubular layer, the inner tubular layer defining a second wall thickness;
wherein the inner tubular layer is relatively rigid with respect to the outer tubular layer, and wherein the first wall thickness is relatively thick with respect to the second wall thickness.
37 . The instrument according to claim 36 , wherein the outer tubular layer exhibits a modulus of elasticity of about 52,600 psi.
38 . The instrument according to claim 37 , wherein the outer tubular layer comprises a thermoplastic elastomer.
39 . The instrument according to claim 36 , wherein the inner tubular layer exhibits a modulus of elasticity of about 6×10 6 psi.
40 . The instrument according to claim 39 , wherein the inner tubular layer comprises a nitinol tube.
41 . The instrument according to claim 39 , wherein the inner tubular layer comprises a stainless steel tube.
42 . The instrument according to claim 41 , wherein the stainless steel tube comprises lateral notches formed therein to facilitate lateral bending of the flexible portion of the elongated shaft.
43 . The instrument according to claim 42 , wherein the lateral notches are arranged in a helical pattern along a length of the stainless steel tube.
44 . The instrument according to claim 36 , wherein the flexible portion exhibits an axial rigidity of about 20,000 lb and flexural rigidity of about 60 lb· 2 .
45 . The instrument according to claim 36 , wherein the second wall thickness is about 5-15 percent of the first wall thickness.
46 . The instrument according to claim 36 , wherein the flexible portion exhibits sufficient axial rigidity to maintain a shape and orientation of the flexible portion in a non-aligned configuration with respect to the longitudinal axis during normal surgical use of the instrument.
47 . The instrument according to claim 46 , wherein the flexible portion includes at least one passageway defined therein, and wherein the instrument includes at least one tensile member extending through the passageway and coupled to the end effector, the at least one tensile member being movable to induce motion in the end effector.
48 . The instrument according to claim 47 , wherein the elongated shaft includes an articulating portion movable between an aligned configuration and an articulated configuration with respect to the flexible portion.
49 . The instrument according to claim 48 , wherein the at least one tensile member includes a pair of steering cables coupled to the end effector such that a differential tension in the pair of steering cables induces articulation of the end effector in a first plane of articulation.
50 . The instrument according to claim 49 , wherein a general tension is imparted to the pair of steering cables when the end effector is in the aligned configuration.
51 . The instrument according to claim 48 , wherein the articulating portion includes a plurality of links arranged sequentially such that each of the links may pivot relative to a neighboring link to move the articulating portion between the aligned and articulated configurations.
52 . The instrument according to claim 51 , wherein a first pivoting axis defined by one of the links is radially offset from a second pivoting axis defined by another of the plurality of links by about 90° to define a second plane of articulation that is substantially orthogonal to the first plane of articulation.
53 . The instrument according to claim 49 , further comprising a second pair of steering cables extending through the least one passageway and coupled to the end effector such that a differential tension in the second pair of steering cables pivots the links about the second pivoting axis to induce articulation of the end effector in the second plane of articulation.
54 . An endoscopic surgical instrument comprising:
an end effector including a pair of jaw members, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion to permit the end effector to articulate with respect to the longitudinal axis, the flexible portion including an anisotropic tube, the tube exhibiting a modulus of elasticity that generally decreases as a function of radius.
55 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration; and
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion movable to a non-aligned configuration with respect to the longitudinal axis, the flexible portion defining at least one helical passageway therethrough; and
at least one tensile member extending through the helical passageway and coupled to the end effector, the at least one tensile member movable to induce motion in the end effector.
56 . The instrument according to claim 55 , wherein the at least one helical passageway traverses a radial arc of about 360 degrees.
57 . The instrument according to claim 55 , wherein the at least one helical passageway defines a helical lumen extending through an interior of the flexible portion of the elongated shaft.
58 . The instrument according to claim 55 , wherein the flexible portion exhibits sufficient rigidity to maintain a shape and orientation of the flexible portion in a non-aligned configuration with respect to the longitudinal axis during normal surgical use of the instrument.
59 . The instrument according to claim 58 , wherein the flexible portion includes a composite of a flexible tube and a rigidizing element.
60 . The instrument according to claim 55 , wherein the elongated shaft includes an articulating portion movable between an aligned configuration and an articulated configuration with respect to the flexible portion.
61 . The instrument according to claim 60 , wherein the at least one tensile member includes a pair of steering cables coupled to the end effector such that a differential tension in the pair of steering cables induces articulation of the end effector in a first plane of articulation.
62 . The instrument according to claim 61 , wherein a general tension is imparted to the pair of steering cables when the end effector is in the aligned configuration.
63 . The instrument according to claim 61 , wherein the articulating portion includes a plurality of links arranged sequentially such that each of the links may pivot relative to a neighboring link to move the articulating portion between the aligned and articulated configurations.
64 . The instrument according to claim 63 , wherein a first pivoting axis defined by one of the links is radially offset from a second pivoting axis defined by another of the plurality of links by about 90° to define a second plane of articulation that is substantially orthogonal to the first plane of articulation.
65 . The instrument according to claim 64 , further comprising a second pair of steering cables extending through the least one helical passageway and coupled to the end effector such that a differential tension in the second pair of steering cables pivots the links about the second pivoting axis to induce articulation of the end effector in the second plane of articulation.
66 . An endoscopic surgical instrument for sealing tissue, comprising:
an end effector including a pair of jaw members adapted to connect to a source of electrosurgical energy, at least one jaw member of the pair of jaw members being movable relative to the other to move the end effector between an open configuration wherein the jaw members are substantially spaced for receiving tissue and a closed configuration wherein the jaw members are closer together for contacting the tissue;
a handle being manually movable to selectively induce motion in the end effector between the open configuration and the closed configuration;
an elongated shaft defining a longitudinal axis and including distal and proximal ends, the distal end coupled to the end effector and the proximal end coupled to the handle, the elongated shaft including a flexible portion to permit the end effector to articulate with respect to the longitudinal axis, the flexible portion defining a shaft axis extending centrally therethrough, the flexible portion including a passageway extending therethrough, the passageway including a first longitudinal length disposed on a first lateral side of the shaft axis and a second longitudinal length disposed on an opposed lateral side of the shaft axis; and
a tensile member extending through the passageway and coupled to the end effector such that longitudinal motion of the tensile member induces motion in the end effector.
67 . The instrument according to claim 66 , wherein the passageway is helically arranged through the flexible portion.
68 . The instrument according to claim 67 , wherein the first and second longitudinal lengths are about equal with respect to one another.
69 . The instrument according to claim 67 , wherein the passageway defines a groove on an exterior surface of a tubular member.
70 . The instrument according to claim 66 , wherein the elongated shaft includes an articulating portion movable between an aligned configuration and an articulated configuration with respect to the longitudinal axis, and wherein the longitudinal motion of the tensile member induces movement of the articulation portion between the aligned and articulated configurations.
71 . The instrument according to claim 70 , wherein the tensile member is substantially elastic.
72 . The instrument according to claim 70 , wherein the articulating portion includes a plurality of links arranged sequentially such that each of the links may pivot relative to a neighboring link to move the articulating portion between the aligned and articulated configurations.