U.S. patent application number 12/508478 was filed with the patent office on 2011-01-27 for articulating mechanism.
Invention is credited to Cameron Dale HINMAN.
Application Number | 20110022078 12/508478 |
Document ID | / |
Family ID | 43497963 |
Filed Date | 2011-01-27 |
United States Patent
Application |
20110022078 |
Kind Code |
A1 |
HINMAN; Cameron Dale |
January 27, 2011 |
ARTICULATING MECHANISM
Abstract
An articulating mechanism is provided with at least one pair of
spherical joints interconnected by a set of tension members. Each
joint includes a ball member, a socket member configured to
pivotably receive at least a portion of the ball member, and at
least one tension member extending through both the ball and socket
members parallel to and offset from a central longitudinal axis of
the joint.
Inventors: |
HINMAN; Cameron Dale;
(Thurmond, NC) |
Correspondence
Address: |
PATENT DEPT;INTUITIVE SURGICAL OPERATIONS, INC
1266 KIFER RD, BUILDING 101
SUNNYVALE
CA
94086
US
|
Family ID: |
43497963 |
Appl. No.: |
12/508478 |
Filed: |
July 23, 2009 |
Current U.S.
Class: |
606/206 ;
403/123; 600/106 |
Current CPC
Class: |
A61B 17/29 20130101;
A61B 2017/291 20130101; F16C 2316/10 20130101; Y10T 74/20323
20150115; A61B 2017/2927 20130101; F16C 11/0614 20130101; Y10T
403/32639 20150115; A61B 2017/2911 20130101; Y10T 403/32 20150115;
A61B 17/2909 20130101; A61B 2017/003 20130101; A61B 2017/2925
20130101; B25J 17/00 20130101; A61B 2017/00327 20130101; A61B
2017/2908 20130101; Y10T 403/32032 20150115; A61B 2017/00314
20130101 |
Class at
Publication: |
606/206 ;
600/106; 403/123 |
International
Class: |
A61B 17/28 20060101
A61B017/28; A61B 1/00 20060101 A61B001/00; F16C 11/06 20060101
F16C011/06 |
Claims
1. An articulating mechanism comprising: at least one pair of
longitudinally spaced apart spherical joints, each joint comprising
a convex component and a mating concave component configured to
receive at least a portion of the convex component, both components
having spherical surfaces adapted to slide relative to one another;
and at least one set of tension members interconnecting one
component of one of the joints of a pair to one component of the
other joint of the pair such that movement of one of the
interconnected components causes corresponding relative movement of
the other interconnected component directly through tension member
movement, wherein each of the convex and concave components
includes a plurality of channels, each channel sized to receive one
of the tension members and the channels in at least one of the
components having an opening located on the spherical surface of
the component, wherein the channels located in mating convex and
concave components form pairs of opposing channels, at least one of
the pairs of opposing channels cooperating with a common tension
member received therein to transmit torque between the mating
components.
2. The articulating mechanism of claim 1 further comprising at
least two of the pairs of longitudinally spaced apart spherical
joints, each of the pairs having a discrete set of tension members
associated with it.
3. The articulating mechanism of claim 2 further comprising an
intermediate member such that each pair of joints has one joint on
one side of the member and one joint on the other side of the
member.
4. The articulating mechanism of claim 3 wherein the intermediate
member comprises a rigid tube configured for receiving the tension
members therethrough.
5. The articulating mechanism of claim 2 wherein the convex
component of one of the joints is integrally formed as a single
part with the concave component of another of the joints.
6. The articulating mechanism of claim 2 wherein the convex
component of one of the joints is integrally formed as a single
part with the convex component of another of the joints.
7. The articulating mechanism of claim 2 wherein the concave
component of one of the joints is integrally formed as a single
part with the concave component of another of the joints.
8. The articulating mechanism of claim 1 wherein at least one of
the convex members comprises a truncated sphere.
9. The articulating mechanism of claim 1 wherein at least one of
the convex members comprises a frusto-sphere.
10. The articulating mechanism of claim 1 wherein at least one of
the channels opens radially outward through a circumferential edge
of the component.
11. The articulating mechanism of claim 1 wherein each of the
convex and concave components comprises a central axial bore
therethrough.
12. The articulating mechanism of claim 1 wherein at least one
mating pair of convex and concave components has exactly 4 tension
member channels running through each component.
13. The articulating mechanism of claim 1 wherein at least one
mating pair of convex and concave components has exactly 8 tension
member channels running through each component.
14. The articulating mechanism of claim 1 wherein the channels in
at least one concave component are radially interconnected to form
a cross-pattern.
15. A spherical joint comprising: a ball member; a socket member
configured to pivotably receive at least a portion of the ball
member; and at least one tension member extending through both the
ball and socket members parallel to and offset from a central
longitudinal axis of the joint.
16. An articulating mechanism for remote manipulation of a surgical
or diagnostic tool comprising: multiple pairs of links, each link
of each pair being maintained in a spaced apart relationship
relative to the other link of the pair, and multiple sets of
tension members, with each set connecting the links of a discrete
pair to one another, such that movement of one link of a pair
causes corresponding relative movement of the other link of the
pair, wherein each link is part of a spherical joint having mating
convex and concave surfaces, and wherein the tension members extend
through channels in the mating surfaces.
17. The articulating mechanism of claim 16 wherein the links form
proximal and distal ends with links of corresponding pairs being
located adjacent to the proximal and distal ends respectively and
where movement of the proximal end results in corresponding
relative movement of the distal end.
18. The articulating mechanism of claim 17 further comprising a
handle located at the proximal end and a grasper at the distal end.
Description
FIELD OF THE INVENTION
[0001] This invention relates to articulating mechanisms and
applications thereof, including the remote guidance and
manipulation of surgical or diagnostic tools.
BACKGROUND OF THE INVENTION
[0002] Surgical procedures such as endoscopy and laparoscopy
typically employ instruments that are steered within or towards a
target organ or tissue from a position outside the body. Examples
of endoscopic procedures include sigmoidoscopy, colonoscopy,
esophagogastroduodenoscopy, and bronchoscopy, as well as newer
procedures in natural orifice transluminal endoscopic surgery
("NOTES"). Traditionally, the insertion tube of an endoscope is
advanced by pushing it forward, and retracted by pulling it back.
The tip of the tube may be directed by twisting and general up/down
and left/right movements. Oftentimes, this limited range of motion
makes it difficult to negotiate acute angles (e.g., in the
rectosigmoid colon), creating patient discomfort and increasing the
risk of trauma to surrounding tissues.
[0003] Laparoscopy involves the placement of trocar ports according
to anatomical landmarks. The number of ports usually varies with
the intended procedure and number of instruments required to obtain
satisfactory tissue mobilization and exposure of the operative
field. Although there are many benefits of laparoscopic surgery,
e.g., less postoperative pain, early mobilization, and decreased
adhesion formation, it is often difficult to achieve optimal
retraction of organs and maneuverability of conventional
instruments through laparoscopic ports. In some cases, these
deficiencies may lead to increased operative time or imprecise
placement of components such as staples and sutures.
[0004] Steerable catheters are also well known for both diagnostic
and therapeutic applications. Similar to endoscopes, such catheters
include tips that can be directed in generally limited ranges of
motion to navigate a patient's vasculature. There have been many
attempts to design endoscopes and catheters with improved
steerability. For example, U.S. Pat. No. 3,557,780 to Sato; U.S.
Pat. No. 5,271,381 to Ailinger et al.; U.S. Pat. No. 5,916,146 to
Alotta et al.; U.S. Pat. No. 6,270,453 to Sakai, and U.S. Pat. No.
7,147,650 to Lee describe endoscopic instruments with one or more
flexible portions that may be bent by actuation of a single set of
wires. The wires are actuated from the proximal end of the
instrument by rotating pinions (Sato), manipulating knobs (Ailinger
et al.), a steerable arm (Alotta et al.), by a pulley mechanism
(Sato), or by manipulation of complementary portions (Lee). U.S.
Pat. No. 5,916,147 to Boury et al. discloses a steerable catheter
having four wires that run within the catheter wall. Each wire
terminates at a different part of the catheter. The proximal ends
of the wires extend loosely from the catheter so that the physician
may pull them. The physician is able to shape and thereby steer the
catheter by selectively placing the wires under tension.
[0005] Recently, surgical instruments, including minimally invasive
surgical instruments, have been developed that are more ergonomic
and which have a wider range of motion and more precise control of
movement. These instruments may include mechanisms that articulate
using a series of links coupled with one or more sets of tension
bearing members, such as cables. As with conventional instruments
used in minimally invasive surgery, rotation of the shaft and end
effector with respect to the handle is also an important feature of
cable and link type instruments to aid with dissecting, suturing,
retracting, knot tying, etc. The links, joints, and other
components of existing instrument articulation mechanisms include
various undesirable limitations. With the increasing complexity
associated with surgical procedures that these instruments are used
to perform, further improvements in the design of the articulation
mechanisms of the instruments are desirable.
SUMMARY OF THE INVENTION
[0006] According to aspects of the invention, articulating tools
are provided with improved articulating mechanisms as well as
methods of assembling such tools. In some embodiments, the
articulating tool is appropriate for multiple uses, including
medical uses such as diagnostic and surgical uses.
[0007] In some embodiments, an articulating mechanism comprises at
least one pair of longitudinally spaced apart spherical joints.
Each joint may include a convex component and a mating concave
component. The concave component is configured to receive at least
a portion of the convex component. Both components may have
spherical surfaces adapted to slide relative to one another. The
articulating mechanism further comprises at least one set of
tension members interconnecting one component of one of the joints
of a pair to one component of the other joint of the pair. With
this arrangement, movement of one of the interconnected components
causes corresponding relative movement of the other interconnected
component directly through tension member movement. Each of the
convex and concave components includes a plurality of channels.
Each channel is sized to slidably receive one of the tension
members. Each channel on at least one of the components has an
opening located on the spherical surface of the component. The
channels located in mating convex and concave components form pairs
of opposing channels. At least one of these pairs of opposing
channels cooperates with a common tension member received therein
to transmit torque between the mating components.
[0008] In some of the above embodiments, the articulating mechanism
further comprises at least two pairs of longitudinally spaced apart
spherical joints. Each of the pairs may have a discrete set of
tension members associated with it. The mechanism may further
comprise an intermediate member such that each pair of joints has
one joint on one side of the member and one joint on the other side
of the member. The intermediate member may comprise a rigid tube
configured for receiving the tension members therethrough. The
convex component of one of the joints may be integrally formed as a
single part with the concave component of another of the joints.
The convex component of one of the joints may be integrally formed
as a single part with the convex component of another of the
joints. The concave component of one of the joints may be
integrally formed as a single part with the concave component of
another of the joints.
[0009] In some of the above embodiments, at least one of the convex
members comprises a truncated sphere. At least one of the convex
members may comprise a frusto-sphere. At least one of the channels
may open radially outward through a circumferential edge of the
component. In some embodiments, each of the convex and concave
components comprises a central axial bore therethrough. In some
embodiments, at least one mating pair of convex and concave
components has exactly 4 tension member channels running through
each component, and/or at least one mating pair of convex and
concave components has exactly 8 tension member channels running
through each component. The channels in at least one concave
component may be radially interconnected to form a
cross-pattern.
[0010] According to aspects of the invention, a spherical joint may
be provided that comprises a ball member, a socket member and at
least one tension member. The socket member may be configured to
pivotably receive at least a portion of the ball member. The
tension member(s) may extend through both the ball and socket
members parallel to and offset from a central longitudinal axis of
the joint.
[0011] In some embodiments, an articulating mechanism for remote
manipulation of a surgical or diagnostic tool is provided. The tool
may comprise multiple pairs of links. Each link of each pair may be
maintained in a spaced apart relationship relative to the other
link of the pair. The mechanism may further comprise multiple sets
of tension members. Each set of tension members may connect the
links of a discrete pair to one another, such that movement of one
link of a pair causes corresponding relative movement of the other
link of the pair. Each link may be part of a spherical joint having
mating convex and concave surfaces. The tension members may extend
through channels in the mating surfaces.
[0012] In some of the above embodiments, the links form proximal
and distal ends with links of corresponding pairs being located
adjacent to the proximal and distal ends, respectively. In these
embodiments, movement of the proximal end results in corresponding
relative movement of the distal end. The articulating mechanism may
further comprise a handle located at the proximal end and a grasper
at the distal end.
INCORPORATION BY REFERENCE
[0013] All publications and patent applications mentioned in this
specification are herein incorporated by reference to the same
extent as if each individual publication or patent application was
specifically and individually indicated to be incorporated by
reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The novel features of the invention are set forth with
particularity in the claims that follow. A better understanding of
the features and advantages of the present invention will be
obtained by reference to the following detailed description that
sets forth illustrative embodiments, in which the principles of the
invention are utilized, and the accompanying drawings which are
briefly described below.
[0015] FIG. 1A is an obliquely distal-looking perspective view of
an exemplary articulating device having a handle and an end
effector. FIG. 1B is a detailed view of the circled portion of FIG.
1A, which includes proximal links and bushings.
[0016] FIG. 2 shows the device of FIG. 1 in a proximal-looking
view, with the handle and end effector in an articulated position.
FIG. 2B is a detailed view of the circled portion of FIG. 2A, which
includes distal links and bushings.
[0017] FIG. 3 is an exploded perspective view of certain proximal
components of the articulating device.
[0018] FIGS. 4A, 4B, 4C, 4D, 4E, 5A, 5B and 6A, 6B show details of
a combination link and busing member for use with the articulating
device.
[0019] FIGS. 7A, 7B and 8A, 8B, 8C, 8D, 8E show details of convex
bushing components for use with the articulating device.
[0020] FIG. 9 shows details of a double-ended convex bushing
component formed as a single unitary piece.
[0021] FIGS. 10A, 10B and 11A, 11B show details of another convex
bushing component for use with the articulating device.
[0022] FIGS. 12A, 12B, and 13A, 13B, 13C show details of a concave
link member for use with an articulating device.
[0023] FIG. 14A, 14B, 14C shows details of another concave link
member for use with an articulating device.
[0024] FIGS. 15-16 show details of an articulating mechanism
located on the distal end of an instrument according to aspects of
the invention.
[0025] FIGS. 17A, 17B, 17C, 17D, 17E, 18A, 18B, 18C, 18D, 19A, 19B,
19C, and 20A, 20B show details of an alternative articulating
mechanism.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Articulating tools are described in U.S. Pat. No. 7,090,637;
US 2005/0107667; US 2005/0273084; US 2005/0273085; US 2006/0111209,
US 2006/0111210, and US 2006/0111615. The articulating mechanisms
of the tools described in those publications use multiple pairs of
segments or links controlled, e.g., by multiple sets of cables, as
well as tools that have a single pair of links, connected by a
single set of cables, such as those described in U.S. Pat. No.
5,916,146. Depending upon the specific design of the device, the
links can be discrete segments (as described, e.g., in U.S. Pat.
No. 7,090,637) or discrete portions of a flexible segment (as
described, e.g., in US 2005/0273085). The instrument may also
include steerable or controllable links, e.g., as described in US
2005/0273084, US 2006/0111209 and US 2006/0111210. The devices of
this invention may include optional end effectors at their distal
ends and end effector actuators supported by a handle at their
proximal ends. When using such articulating instruments, a user may
manipulate the proximal end of the instrument, thereby moving one
or more distal links of the articulation mechanism. Aspects of the
present invention may be used in any of these and in other
articulating mechanisms.
[0027] FIGS. 1A and 2A show an exemplary articulatable tool 100
with an end effector 102 at its distal end and an end effector
actuator 104 within a handle 106 at its proximal end: FIG. 1A shows
the tool in a neutral or non-articulated configuration, while FIG.
2A shows the tool in an articulated position or configuration. FIG.
1B shows detail (encircled in FIG. 1A) of the proximal links of the
tool. FIG. 2B shows detail (encircled in FIG. 2A) of the distal
links of the tool. Instrument 100 may be used, e.g., in a
laparoscopic procedure requiring grasping or cutting within a
patient. Exemplary embodiments of the tool 100 may also be useful
in endoscopic procedures, particularly when, as in some
embodiments, the tool has a flexible shaft. Still other embodiments
may be used for percutaneous procedures, such as a catheter. Still
other embodiments include devices that are directed toward natural
orifice transluminal endoscopic surgery ("NOTES"). Embodiments of
the invention may include a wide variety of tools, some with
medical or diagnostic purposes, and others that are applied to
other types of tasks where the articulational capabilities of the
tool provide benefit.
[0028] Proximal articulation links 108 and 110 extend distally from
handle 106, and distal articulation links 112 and 114 extend
proximally from end effector 102. Proximal link 108 is a spindle
and is connected to and moves with handle 106. Likewise, distal
link 112 is connected to and moves with end effector 102. An
elongated shaft 116 is disposed between the proximal links and the
distal links; in some embodiments the shaft is rigid, in other
embodiments the shaft may be flexible.
[0029] A set of tension bearing elements or control cables 118 is
attached to proximal link 108, extends through proximal link 110,
shaft 116 and distal link 114 and is attached to distal link 112,
as shown in FIGS. 1A and 1B. A second set of tension bearing
element or control cables 120 is attached to proximal link 110,
extends through shaft 116 and is attached to distal link 114. In
this embodiment, there are three control cables 118 in the first
set and three control cables 120 in the second set. It should be
appreciated, however, that other numbers of control cables may be
used to connect corresponding proximal and distal links. In
addition, tension bearing elements other than cables may be used to
connect corresponding links. In some embodiments, the tension
members may comprise cables that are capable of only transmitting
tension between the links. In other embodiments, the tension
members may comprise Nitinol wires, rods or other elements capable
of transmitting both tension and compression. In these latter
embodiments, a link may be alternately pushed and pulled by at
least one tension member. In some embodiments, one set of control
cables, such as cables 120, may be eliminated to provide an
instrument with a single pair of connected links. What is meant by
the word "connected" is that the cable(s) are attached to a pair of
links to allow one link to drive another link, as opposed to the
cables merely slidably passing through the connected links.
[0030] As shown in FIGS. 1A, 1B, 2A, and 2B, movement of handle 106
and proximal link 108 with respect to proximal link 110 moves end
effector 102 and distal link 112 in a relative and corresponding
manner. Likewise, movement of proximal link 110 with respect to
shaft 116 moves distal link 114 with respect to shaft 116 in a
relative and corresponding manner, also as shown in FIG. 2. This
relative articulation movement provides a way for a user to
remotely manipulate the end effector through movement of the
handle. It should be understood that the proximal and distal links
can be connected by the tension bearing elements so as to move in
the same direction with respect to the shaft (thereby providing a
mirror image movement) or in opposite directions with respect to
the shaft, depending on whether the tension bearing elements
connect the corresponding links on the opposite sides or on the
same sides of the links, respectively. In addition, the degree of
relative movement can be determined by the relative diameters of
the cables' connections to corresponding links as well as through
the use and specific design of bushings or spacer links separating
the connected proximal and distal links. For example, in the
embodiment shown in FIGS. 1-3, the cables' radial spacing on the
proximal links is about three times greater than their radial
spacing on the distal links. This means that a movement of about
5.degree. in a proximal link will cause a corresponding movement of
about 15.degree. in a distal link. Further details of these links
are provided in US2005/0273085, which is hereby incorporated by
this reference.
[0031] In the embodiment illustrated in FIG. 1, the end effector
102 is a pair of jaws. Actuation force is transmitted from end
effector actuator 104 through a transmission that includes a
linearly movable rod and a rotatable rod actuator (not shown).
Other end effectors (surgical, diagnostic, etc.) and end effector
actuators may be used with an articulating tool constructed
according to this invention. In some embodiments, the distal links
themselves can comprise an end effector, such as, for example, a
retractor. The movable rod may comprise any flexible material; in
some embodiments Nitinol offers particular advantages as it is
sufficiently flexible to accommodate articulation, and yet can
still carry a compressive load sufficiently, for example, to be
able to push open an end effector, such as a set of jaws. In some
embodiments, a series of proximal links, themselves, can comprise a
"handle" with no other rigid handle being provided. In other words,
the proximal links may be formed into a particular shape which is
emulated by a corresponding series of distal links. More details of
such embodiments are provided in U.S. Pat. No. 7,090,637.
[0032] FIG. 3 shows an exploded view of certain proximal components
of the articulating tool. The tension members have been omitted for
clarity. As shown, a double headed bushing 109 is disposed between
links 108 and 110, and another bushing 111 is disposed between
links 110 and a proximal end cap 300. The interaction of bushings
109 and 111 with links 108 and 110 and with proximal end cap 300 is
described in more detail in U.S. 2005/0273084, U.S. 2006/0111209,
and U.S. 2006/0111210. If the tension bearing cables 118 and 120
were shown in FIG. 3 as they are in FIGS. 1 and 2, the proximal
ends of the three cables 118 would terminate in openings 1806 of
link 108, and the cables would pass through openings 1820 in link
110 and openings 304 in end cap 300 before entering shaft 116.
Likewise, the proximal ends of three cables 120 would terminate in
openings 1822 of link 110 and would pass through openings 304 in
proximal end cap 300 before entering shaft 116. A tapered end cap
housing or cover 306 may be rigidly fixed to shaft 116 to provide a
transition from end cap 300 to shaft 116.
[0033] As previously noted, device 100 shown in FIGS. 1-3 includes
two pairs of links, each interconnected by its own set of tension
members. Specifically, one pair is formed by proximal link 108 and
distal link 112 which are interconnected by tension members 118,
and another pair is formed by proximal link 110 and distal link 114
which are interconnected by tension members 120. In other
embodiments, only a single pair of links interconnected by a single
set of tension members is used. In yet other embodiments, three or
more pairs of links may be used, each interconnected by a discrete
set of tension members. In some embodiments, instead of a set of
tension members, only a single tension member may be used between a
pair of links, such as when the tension member is capable of also
transmitting compression between the links.
[0034] As shown in FIG. 3, proximal links 108 and 110 are separated
by bushing 109, and proximal link 110 is separated from proximal
end cap 300 by bushing 111. Proximal bushings 109 and 110 each have
a convex spherical component or ball located at each of their ends.
Mating concave recesses are formed in proximal links 108 and 110
and in proximal end cap 300 for receiving a portion of the ball
ends of the bushings. With this arrangement, proximal links 108 and
110 pivot relative to one another about two pivot points (i.e.
about the centers of the two ball ends of bushing 109). Similarly,
proximal link 110 and end cap 300 pivot relative to one another
about two pivot points (i.e. about the centers of the two ball ends
of bushing 111). In other embodiments, some of which are later
described, links may pivot relative to one another about a single
pivot point. In the embodiment shown in FIG. 3, protruding pin
features are located on opposite sides of each ball and are
pivotably received within mating slots located in the concave
recesses. This pin and slot configuration allows torque to be
transmitted across the four proximal spherical joints. Distal links
112 and 114, and distal end cap 400 are separated by bushings in a
similar arrangement. As can be seen by the radial location of
tension member channels 1806, 1807, 1820, 1822 and 304 relative to
the concave recesses, the tension members travel axially along
lines that are radially outside of the spherical joint surfaces in
this embodiment.
[0035] FIGS. 4A-4E show details of a combination link and bushing
member 500 that may be used in any of the articulating devices
described above. For example, member 500 may be used to replace
link 110 and bushing 111 shown in FIG. 3, and a component similar
to member 500 may be used to replace link 108 and bushing 109.
[0036] Link and bushing member 500 comprises a concave component
502 and a complementary-shaped convex component 504, which may be
integrally formed therewith as shown. A central axial bore 506 may
be provided through member 500. Concave component 502 includes a
recess having a concave spherical surface 508. In this embodiment,
spherical surface 508 is bounded above by rim surface 510 and below
by stop surface 512, which is further described below. Concave
spherical surface 508 is interrupted by the upper openings of four
channels 514 that travel axially through the concave component and
in this embodiment are evenly spaced around the central axial bore
506.
[0037] The convex component of member 500 includes a portion having
the overall shape of a frustro-sphere, as best seen in FIG. 4D.
This frusto-sphere is circumferentially interrupted by four
channels 516 that extend axially in line with channels 514, but
also extend radially outward to divide the frustro-sphere into four
convex spherical surfaces 518. As best seen in FIG. 4D, each
channel 516 is outwardly tapered at both its top and bottom to
generally form an hourglass shape.
[0038] FIGS. 5A-5B show two link and bushing members 500, 500
axially coupled together in operation. As can be seen in FIG. 5B,
the convex component 504 of the upper member 500 is received within
the concave component 502 of the lower member 500 to form a
spherical joint. In this embodiment, the spherical joint is capable
of pivoting in at least two degrees of freedom. Dimensions may be
appropriately chosen such that the four convex spherical surfaces
518 slidably engage with the concave spherical surface 508 but
lateral movement between the spherical surfaces is generally
prevented. Stop surface 512 may be provided in the lower concave
component for abutting against the bottom surface 520 of the upper
convex component to limit the degree of angular rotation permitted
between the two members 500, 500. In some embodiments, the degree
of angular rotation permitted by stop surface 520 is symmetrical
about the central longitudinal axis, and in other embodiments it is
asymmetrical. As shown, each central axial bore 506 may be tapered
at its top and bottom such that any cables, tubes, fiber optics,
etc. passing through the bore are not pinched and do not inhibit
members 500, 500 from pivoting.
[0039] FIG. 6B is a cross-section similar to FIG. 5B, but is
aligned with channels 514 in concave component 502 and channels 516
in convex component 504. Tension members 522, such as for
controlling other links in an articulating system, are shown
passing through channels 514 and 516. The tapering of channels 516
permit members 500, 500 to pivot without tension members 522
binding. In some embodiments of the invention, channels 516 may be
tapered only at their lower ends and not at their upper ends. In
other embodiments, channels 514 in concave component 502 may be
tapered while channels 516 in convex component 504 are straight. In
yet other embodiments, channels in both components 502 and 504 are
tapered. In still other embodiments, channels in both components
502 and 504 are straight and sufficient axial distance between the
channels is provided to inhibit binding of tension members 522
during pivoting movement.
[0040] With the arrangement shown in FIG. 6B, torque may be
transmitted between members 500, 500 by tension members 522 without
the need for protrusions and slots as previously described in
relation to FIG. 3. It can be appreciated that the shorter the
distance between channels 514 and 516 and the closer that these
channels constrain tension members 522, the less axial rotation or
backlash there will be between members 500, 500 for a given
torque.
[0041] Spherical joints constructed as described above may be
provided with mating spherical surfaces that are larger than those
of conventional spherical joints for a given joint envelope because
they are not outwardly constrained by ball protrusions, socket
slots, or tension members that are located radially outward from
the mating spherical surfaces. Larger surface sizes may provide
additional benefits such as being able to carry more load, allow
for looser tolerance control and/or greater instrument rigidity.
Such an arrangement may also allow one or more components of the
joint to be made out of lighter, cheaper or disposable material
such as plastic.
[0042] FIGS. 7A-7B and 8A-8E show details of convex bushing
components 550 that may be used in any of the articulating devices
described above. For example, components 550 may be used in pairs
in a similar manner to proximal bushings 109 and 111 shown in FIG.
3, and/or in the distal articulating mechanism of a grasper
instrument as shown in FIG. 16.
[0043] Convex components 550 are constructed and operate in a
manner similar to that of convex components 504 described above. In
particular, each component 550 includes a portion having the
overall shape of a frustro-sphere, as best seen in FIG. 8A. This
frusto-sphere is circumferentially interrupted by four channels 516
that extend axially through the frusto-sphere, but also extend
radially outward to divide the frustro-sphere into four convex
spherical surfaces 518. As best seen in FIG. 8A, each channel 516
is outwardly tapered at both its top and bottom to generally form
an hourglass shape.
[0044] Each convex component 550 comprises a pair of opposing,
axially protruding ring segments 552 on opposite sides of a central
bore 554, as best seen in FIG. 7A where two components 550 are
shown axially separated. The protruding ring segments 552 of two
facing components 550 may be rotationally oriented as shown in FIG.
7A so that when they are axially drawn together, as shown in FIG.
7B, the four protruding ring segments 552 interdigitate and
rotationally lock the two components 550 together. This creates a
double-ended bushing 556, with each end having a convex component
formed by four spherical surfaces 518. Forming the double-ended
bushing 556 from two separate pieces as shown facilitates
fabrication of the bushing from an injection molding process. As
shown in FIG. 9, a similar double-ended bushing 556' may also be
formed as a single, unitary piece.
[0045] FIGS. 10A-10B and 11A-11B show details of convex bushing
components 550'. Convex components 550' are similar to convex
components 550 described above and shown in FIGS. 7A-7B and 8A-8E,
except that components 550' each have eight channels 516 instead of
four channels 516. This allows up to eight tension members 522
(shown in FIG. 6B) to pass through components 550'. When two convex
bushing components 550' are interengaged as shown in FIG. 10B, they
form a double-ended bushing 556'', with each end having a convex
component formed by eight spherical surfaces 518'. A similar
double-ended bushing (not shown) may also be formed as a single,
unitary piece.
[0046] FIGS. 12A-12B and 13A-13C show details of a concave link
member 560 that may be used in the articulating devices described
above. For example, members 560 may be used in a similar manner to
proximal links 108 and 110 shown in FIG. 3, and/or in the distal
articulating mechanism of a grasper instrument as shown in FIGS. 15
and 16.
[0047] Concave member 560 is constructed and operates in a manner
similar to that of concave component 502 described above. In
particular, a central axial bore 506 may be provided through member
560. A recess having a concave spherical surface 508 is provided at
each end of concave member 560. In this embodiment, each spherical
surface 508 is bounded on the outside by a castellated rim surface
562 or 564, and on the inside by a stop surface 566 or 568. Rim
surfaces 562 and 564 are castellated in order to provide clearance
for the tension members 522 when the device is articulated. Stop
surfaces 566 and 568 function in a manner similar to previously
described stop surface 512. Each concave spherical surface 508 is
interrupted by the openings of eight channels 570 that travel
axially through concave member 560 and in this embodiment are
evenly spaced around the central axial bore 506.
[0048] The recess and spherical surface 508 located on the proximal
end 572 of member 560 (as shown in FIGS. 12A and 13A) are
configured to pivotably engage with the convex spherical surfaces
518' formed on one end of a convex bushing component 550' (shown in
FIGS. 10A-10B and 11A-11B). Similarly, the recess and spherical
surface 508 located on the distal end 574 of member 560 (as shown
in FIGS. 12B and 13C) are configured to pivotably engage with the
convex spherical surfaces 518 formed on one end of a convex bushing
component 550 (shown in FIGS. 7-9).
[0049] As shown in FIG. 13C, the recess located on the distal end
574 of member 560 is provided with two cross channels 576 that
interconnect the distal ends of every other channel 570. This
allows a tension member 522 (not shown in FIG. 13) to pass through
one channel 570 from the proximal end 572 to the distal end 574 of
member 560, cross over to another channel 570, and return to the
proximal end 572 through the other channel 570. Surface friction
(or in some embodiments, adhesive, solder, crimping, or the like)
keeps tension members 522 from sliding in cross channels 576. In
this manner, the four tension member portions that extend through
the four channels 570 connected to cross channels 576 can be used
to control the pivoting motion of concave link member 560, while
four other tension members 522 can pass through member 560 in the
remaining four channels 570 to control another link located distal
to member 560, as will be more fully described below.
[0050] FIGS. 14A-14C show details of a concave link member 560'.
Member 560' is similar in construction and operation to that of
member 560, except member 560' has only four axial channels 570
through it instead of eight.
[0051] FIGS. 15 and 16 show details of the distal end of an
articulating instrument, similar to instrument 100 shown in FIGS.
1-3 and having a distal articulating mechanism 578 similar to the
articulating mechanism shown in FIG. 2B. The distal end of the
instrument includes a pair of graspers 580 that may be operated by
an actuator (not shown) located at the proximal end of the
instrument.
[0052] Distal articulating mechanism 578 includes a double-ended
convex bushing 556, a concave link member 560, and a double-ended
convex bushing 556'', all as previously described. A distal link
582, constructed in a similar manner to one half of concave link
member 560 shown in FIGS. 14A-14C, may be formed on grasper housing
584. Similarly, a recess 586, constructed in a similar manner to
the proximal end 572 of concave member 560 shown in FIGS. 12-13,
may be provided on the distal end of instrument shaft 588. With
this arrangement, concave distal link 582 may pivot relative to
concave link member 560 about the centers of the two spherical ends
of double-ended convex bushing 556. Similarly, concave link member
560 may pivot relative to recess 586 about the centers of the two
spherical ends of double-ended convex bushing 556''.
[0053] An articulating mechanism similar to distal articulating
mechanism 578 may be used at the proximal end of the instrument,
although its relative size may be larger or smaller to provide
scaling of movement. In this exemplary embodiment, one set of four
tension members 522 interconnects the innermost links (i.e. distal
link 560 and the proximal link (not shown in FIG. 15 or 16) closest
to shaft 588). A separate set of four more tension members 522
interconnects the outermost links (i.e. distal link 582 and the
proximal link (not shown in FIG. 15 or 16) farthest from shaft
588). With this arrangement, movement of the instrument handle (not
shown) causes movement of the two proximal links which in turn
drive corresponding movement of their respective distal links 560
and 582 directly through movement of the associated tension members
522.
[0054] FIGS. 17-20 show details of an alternative embodiment of
articulating mechanism 600. The construction and operation of
mechanism 600 is similar to previously described articulating
mechanism 578, but the convex and concave portions have been
reversed. In other words, the convex components 602 are located on
the links 604, and the concave components 606 are located on the
bushings 608. As previously described, each of the components may
be provided with a central axial bore 610 and 612, respectively,
which may be tapered at one or both ends. Additionally, axial
channels 614 in links 604 and axial channels 616 in bushing 608 for
receiving tension members 522 may be tapered at one or both ends.
As best seen in FIGS. 18A and 18B, the tension member channels 616
in bushing 608 may be elongated such that they form a single
cross-shaped opening with central bore 612.
[0055] As with the previous embodiments described, articulating
mechanism 600 is able to transmit torque between the links 604 and
bushings 608 through tension members 522 without the use of other
torque transmitting features on the components. In other
embodiments (not shown), articulating joints may be configured such
that torque is not readily transmitted between the components by
tension members 522, but other advantages are nonetheless conferred
by locating the tension members through one or more mating
spherical surfaces of the joints.
[0056] While the inventive surgical instruments and devices with
improved articulating mechanisms have been described in some detail
by way of illustration, such illustration is for purposes of
clarity of understanding only. It will be readily apparent to those
of ordinary skill and in the art in light of the teachings herein
that certain changes and modifications may be made thereto without
departing from the spirit and scope of the appended claims. For
example, while the tool embodiments described in here have
typically been in the context of tools with an articulating
mechanism comprising at least two links, the tension member guide
system may be used in an instrument comprising only a single link,
a multiplicity of links, and with any number of tension members
such as cables, or numbers of cable sets operably connecting the
links. Further, the tension member guide system may be used in
tools that are absent various features that may be associated with
some articulatable instruments, such as handles, rotatability
features, and dedicated end effectors. Finally, while the context
of the invention may be considered to be surgical or medical
diagnostic procedures, devices having such an articulation system
may have utility in other non-medical contexts as well.
* * * * *