a2) United States Patent
`US 6,699,235 B2
`(10) Patent No.:
`Wallaceet al.
`(45) Date of Patent:
`Mar.2, 2004
`
`
`US006699235B2
`
`(54) PLATFORM LINK WRIST MECHANISM
`
`
`
`8/1998 Madhani et al... 606/1
`5,792,135 A *
`8/1999 Zirps ct al... 606/170
`5,938,678 A *
`(75) 6,196,081 B1=3/2001 YauInventors: Daniel T. Wallace, Redwood City, CA
`
`(US); S. Christopher Anderson,
`Oree BI * 102001 baal neseseneeeeeeeeenees 600/141
`\
`307,285
`elson et al.
`Manzo.Shelton,CL(US Scott
`6,312,435 BL * 11/2001 Wallace et al. se... 606/130
`,
`?
`6,330,837 B1
`12/2001 Charleset al.
`Intuitive Surgical, Inc., Sunnyvale, CA
`200310028217 AL
`2/2003 Nakamura et al.
`(US)
`* cited by examiner
`
`(73) Assignee:
`
`(*) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 0 days.
`(21) Appl. No.: 10/186,176
`od.
`(22)
`Filed:
`Jun. 28, 2002
`(65)
`Prior Publication Data
`
`(60)
`
`US 2003/0018323 Al Jan. 23, 2003
`Related U.S. Application Data
`Provisional application No. 60/301,967,
`filed on Jun. 29,
`2001, and provisional application No. 60/327.702,
`filed on
`Oct. 5, 2001.
`—
`4
`Int.Ch A61B 17/00; A61B 19/00
`(51)
`(52) US. Cheee 606/1; 74/490.03, 74/490.06;
`606/130
`(58) Field of Search oo... cece 901/29; 606/1,
`606/130, 205; 600/102, 141; 74/490.03,
`490.06, 567; 414/735; 910/23, 19, 16
`.
`References Cited
`US. PATENT DOCUMENTS
`
`(56)
`
`......... 606/205
`3,628,535 A * 12/1971 Ostrowsky et al.
`5,053,687 A * 10/1991 Meret ....eseesseerreeee 318/568.2
`toyfoo. postinsrreeeeeeeeeecees pert
`ees A :
`
`SATASTL A * 12/1995 Lang essen
`606/205
`
`2/1998 Toyama et al... 901/23
`5,715,729 A *
`4/1998 Ballantyne et al.
`...... 74/490.06
`5,740,699 A *
`
`Primary Examiner—Roy D. Gibson
`(74) Attorney, Agent, or Firm—Townsend and Townsend
`and Crew LLP; Lynn M. Thompson
`67)
`ABSTRACT
`The present invention providesa robotic surgical tool for use
`in a robotic surgical system to perform a surgical operation.
`The robotic surgical tool includes a wrist mechanism dis-
`posed near the distal end of a shaft which connects with an
`end effector. The wrist mechanism includesa distal member
`configured to support the end effector, and a plurality of rods
`extending generally along an axial direction within the shaft
`and movable generallyalong this axial direction to adjustthe
`orientation of the distal member with respect to the shaft.
`‘The distal memberhasa base to whichthe rodsare rotatably
`connected by orthogonallinkage assemblies. Advancement
`or retraction of a first rod generally along the axial direction
`tips the base througha first angle so that the distal member
`faces a first articulated direction, such as to provide pitch.
`The addition of a sccond angle allows the distal memberto
`direct the end effector in essentially a compoundangle or in
`a secondarticulated direction in relation to the shaft of the
`surgical tool, such as to provide yaw. The robotic surgical
`tool may also include provisions for roll movement. Roll
`movement is achieved by rotating the plurality of rods
`around a longitudinal axis or the central axis of the shaft
`parallel
`to the axial direction. The robotic surgical tool
`includes a tool base disposed near the proximal end of the
`Shaft.
`
`55 Claims, 24 Drawing Sheets
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`Sheet 4 of 24
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`US 6,699,235 B2
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`1
`PLATFORM LINK WRIST MECHANISM
`
`CROSS-REFERENCES TO RELATED
`APPLICATIONS
`
`This application is based on and claimsthe benefit of U.S.
`Provisional Patent Application No. 60/301,967, filed Jun.
`29, 2001, and No. 60/327,702,filed Oct. 5, 2001, the entire
`disclosures of which are incorporated herein by reference.
`This application is related to the following patents and
`patent applications, the full disclosures of which are incor-
`porated herein by reference:
`PCT International Application No. PCT/US98/19508,
`entitled “Robotic Apparatus”, filed on Sep. 18, 1998,
`and published as WO99/50721;
`US. patent application Ser. No. 09/418,726, entitled
`“Surgical Robotic Tools, Data Architecture, and Use”,
`filed on Oct. 15, 1999;
`US. patent application Ser. No. 60/111,711, entitled
`“Image Shifting for a Telerobotic System”, filed on
`Dee. 8, 1998;
`US. patent application Ser. No. 09/378,173, entitled
`“Stereo Imaging System for Use in Telerobotic
`System’, filed on Aug. 20, 1999;
`US. patent application Ser. No. 09/398,507, entitled
`“Master Having Redundant Degrees of Freedom”, filed
`on Sep. 17, 1999;
`US. application Ser. No. 09/399,457, entitled “Coopera-
`tive Minimally Invasive Telesurgery System”, filed on
`Sep. 17, 1999;
`US. patent application Ser. No. 09/373,678, entitled
`“Camera Referenced Control in a Minimally Invasive
`Surgical Apparatus”, filed on Aug. 13, 1999;
`US. patent application Ser. No. 09/398,958, entitled
`“Surgical Tools for Use in Minimally Invasive Tele-
`surgical Applications”, filed on Sep. 17, 1999; and
`US. Pat. No. 5,808,665, entitled “Endoscopic Surgical
`Instrument and Method for Use”, issued on Sep. 15,
`1998.
`
`
`
`STATEMENT AS TO RIGHTS TO INVENTIONS
`MADE UNDER FEDERALLY SPONSORED
`RESEARCH OR DEVELOPMENT
`
`NOT APPLICABLE
`
`REFERENCE TO A “SEQUENCE LISTING,” A
`TABLE, OR A COMPUTER PROGRAM LISTING
`APPENDIX SUBMITTED ON A COMPACT
`DISK
`
`NOT APPLICABLE
`
`BACKGROUND OF THE INVENTION
`
`The present invention relates generally to surgical tools
`and, more particularly,
`to various wrist mechanisms in
`surgical tools for performing robotic surgery.
`Robotic surgery has developed to improve and expand the
`use of minimally invasive surgical (MIS) techniques in the
`treatment of patients. Minimally invasive techniques are
`aimed at reducing the amount of extraneous tissue that is
`damaged during diagnostic or surgical procedures, thereby
`reducing, patient recovery time, discomfort, and deleterious
`side effects. The average length of a hospital stay for a
`standard surgery may also be shortened significantly using
`MIStechniques. Thus, an increased adoption of minimally
`
`2
`invasive techniques could save millions of hospital days and
`millions of dollars annually in hospital residency costs
`alone. Patient recovery times, patient discomfort, surgical
`side effects and time away from work may also be reduced
`with minimally invasive surgery.
`The most common form of minimally invasive surgery
`may be endoscopy. And, probably the most common form of
`endoscopy is laparoscopy, which is minimally invasive
`inspection and surgery inside the abdominal cavity.
`In
`standard laparoscopic surgery, a patient’s abdomenis insuf-
`flated with gas, and cannula sleeves are passed through small
`(approximately % inch) incisions to provide entry ports for
`laparoscopic surgical instruments. The laparoscopic surgical
`instruments generally include a laparoscope (for viewing the
`surgical field) and working tools. The working tools are
`similar to those used in conventional (open) surgery, except
`that the working end or end effector of each tool is separated
`from its handle by an extension tube. As used herein, the
`term “end effector” means the actual working part of the
`surgical
`instrument and can include clamps, graspers,
`scissors, staplers, and needle holders, for example. To per-
`form surgical procedures, the surgeon passes these working
`tools or instruments through the cannula sleeves to an
`internal surgical site and manipulates them from outside the
`abdomen. The surgeon monitors the procedure by means of
`a monitor that displays an image of the surgical site taken
`from the laparoscope. Similar endoscopic techniques are
`employed in, e.g., arthroscopy,
`retroperitoneoscopy,
`pelviscopy, nephroscopy, cystoscopy, cisternoscopy,
`sinoscopy, hysteroscopy, urethroscopy and the like.
`There are many disadvantages relating to current MIS
`technology. For example, existing MIS instruments denythe
`surgeon the flexibility of tool placement found in open
`surgery. Most current laparoscopic tools have rigid shafts, so
`that it can be difficult to approach the worksite through the
`small incision. Additionally, the length and construction of
`many endoscopic instruments reduces the surgeon’s ability
`to feel forces exerted by tissues and organs on the end
`effector of the associated tool. The lack of dexterity and
`sensitivity of endoscopic tools is a major impedimentto the
`expansion of minimally invasive surgery.
`Minimally invasive tclesurgical robotic systems are being
`developed to increase a surgeon’s dexterity when working
`within an internal surgical site, as well as to allow a surgeon
`to operate on a patient from a remote location. In a telesur-
`gery system, the surgeon is often provided with an image of
`the surgical site at a computer workstation. While viewing a
`three-dimensional image of the surgical site on a suitable
`viewer or display, the surgeon performsthe surgical proce-
`dures on the patient by manipulating master input or control
`devices of the workstation. The master controls the motion
`
`of a servomechanically operated surgical instrument. During
`the surgical procedure, the telesurgical system can provide
`mechanical actuation and control of a variety of surgical
`instruments or tools having end effectors suchas, e.g., tissue
`graspers, needle drivers, or the like, that perform various
`functions for the surgeon, e.g., holding or driving a needle,
`grasping a blood vessel, or dissecting tissue, or the like, in
`response to manipulation of the master control devices.
`Manipulation and control of these end effectors is a
`critical aspect of robotic surgical systems. For these reasons,
`it is desirable to provide surgical tools which include mecha-
`nismsto provide three degrees of rotational movementof an
`end effector around three perpendicular axes to mimic the
`natural action of a surgeon’s wrist. Such mechanisms should
`be appropriately sized for use in a minimally invasive
`procedure andrelatively simple in design to reduce possible
`
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`US 6,699,235 B2
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`3
`In addition, such mechanisms should
`points of failure.
`provide adequate degree of rotation to allow the end ettector
`to be manipulated in a wide variety of positions. At least
`some of these objectives will be met by the inventions
`described hereinafter.
`
`BRIEF SUMMARY OF THE INVENTION
`
`The present invention provides a robotic surgical tool for
`use in a robotic surgical system to perform a surgical
`operation. Robotic surgical systems perform surgical opera-
`tions with tools which are robotically operated by a surgeon.
`Such systems generally include master controllers and a
`robotic arm slave cart. The robotic arm slave cart is posi-
`tioned adjacent to the patient’s body and movesthe tools to
`perform the surgery. The tools have shafts which extend into
`an internal surgical site within the patient body via mini-
`mally invasive access openings. The robotic arm slave cart
`is connected with master controllers which are grasped by
`the surgeon and manipulated in space while the surgeon
`views the procedure on a stereo display. The master con-
`trollers are manual input devices which preferably move
`with six degrees of freedom, and which often further have an
`actuatable handle for actuating the tools (for example, for
`closing grasping saws, applying an electrical potential to an
`electrode,or the like). Robotic surgery systems and methods
`are further described in co-pending U.S. patent application
`Ser. No. 08/975,617,filed Nov. 21, 1997, the full disclosure
`of which is incorporated herein by reference.
`As described, robotic surgical tools comprise an elon-
`gated shaft having a surgical end effector disposed near the
`distal end of the shaft. As used herein, the terms “surgical
`instrument”, “instrument”, “surgical tool”, or “tool” refer to
`a member having a working end which carries one or more
`end effectors to be introduced into a surgical site in a cavity
`of a patient, and is actuatable from outside the cavity to
`manipulate the end effector(s) for effecting a desired treat-
`ment or medical function of a target tissue in the surgical
`site. The instrument or tool typically includes a shaft car-
`rying the end effector(s) at a distal end, and is preferably
`servomechanically actuated by a telesurgical system for
`performing functions such as holding or driving a needle,
`grasping a blood vessel, and dissecting tissue. In addition, as
`used herein, “end effector” refers to the actual working part
`that is manipulable for effecting a predetermined treatment
`of a target tissue. For instance, some end effectors have a
`single working member such as a scalpel, a blade, or an
`electrode. Other end effectors have a pair or plurality of
`working memberssuchas forceps, graspers,scissors,or clip
`appliers, for example.
`the robotic
`In a first aspect of the present invention,
`surgical tool includes a wrist mechanism disposed near the
`distal end of the shaft which connects with the end effector.
`
`The wrist mechanism includes a distal member, configured
`to support the end effector, and a plurality of rods extending
`generally along an axial direction within the shaft and
`movable generally along this axial direction to adjust the
`oricntation of the distal member with respect to the axial
`direction or shaft. The distal member may have any form
`suitable for supporting an end effector.
`In most
`embodiments, the distal member has the form ofa clevis. In
`any case, the distal member has a base to which the rodsare
`rotatably connected.
`Advancement or retraction of a first rod generally along
`the axial direction tips the base througha first angle so that
`the distal memberfaces a first articulated direction. Thefirst
`
`angle may be any angle in the range of 0-90 degrees and
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`oriented so that the first articulated directionis any direction
`that is not parallel to the axial direction. This would allow
`the distal memberto direct an end effector in any direction
`in relation to the shaft of the surgical
`tool.
`In most
`embodiments, the first angle is greater than approximately
`30 degrees. In some embodiments,the first angle is greater
`than approximately 60 degrees and in other embodiments
`the first angle is greater than approximately 70 degrees. This
`first angle may represent the pitch or the yaw of the wrist
`mechanism.
`
`In some embodiments, advancementor retraction of a
`second rod generally along the axial direction tips the base
`through a second angle so that the distal member faces a
`second articulated direction. The second angle mayalso be
`any angle in the range of 0-90 degrees and oriented so that
`the second articulated direction is any direction that is not
`parallel to the axial direction. The addition of a second angle
`would allow the distal member to direct an end effector in
`essentially a compound angle or in a second articulated
`direction in relation to the shaft of the surgical tool. In most
`embodiments,
`the second angle is greater than approxi-
`mately 30 degrees. In some embodiments, the second angle
`is greater
`than approximately 60 degrees and in other
`embodiments the second angleis greater than approximately
`70 degrees. If the first angle represents the pitch of the wrist
`mechanism, the second angle may represent the yaw of the
`wrist mechanism and vice versa.
`
`‘The plurality of rods may comprise two, three, four or
`more rods. In preferred embodiments, three or four rods are
`used to provide both pitch and yaw angulation. When four
`rods are used,
`the first and second rods are positioned
`adjacent
`to each other and the remaining two rods are
`located in positions diametrically opposite to the first and
`second rods. The four rods are generally arranged symmetri-
`cally around a central axis of the shaft or the axial direction.
`When the first rod is advanced, the diametrically opposite
`rod is simultaneously retracted. Likewise, whenthefirst rod
`is retracted, the diametrically opposite rod is simultaneously
`advanced. This is similarly the case with the second rod and
`its diametrically opposite rod. Thus, the rods actuate in pairs.
`Such actuation will be further described in a later section.
`
`To maintain desired positioning of the rods, some embodi-
`ments include a guide tube having a plurality of guideslots.
`Each guide slot is shaped for receiving and guiding one of
`the plurality of rods substantially along the axial direction.
`In some embodiments, the rods are shaped so as to have a
`rectangular cross-section. In these instances, the correspond-
`ing guide slots also rectangular in shape to receive and
`maintain proper orientation of the rods.
`In a second aspect of the present invention, the robotic
`surgical tool includes a tool base disposed near the proximal
`end of the shaft. The tool base includes mechanisms for
`
`actuating the wrist mechanism and often mechanisms for
`actuating the end effector. Mechanisms for actuating the
`wrist mechanism includes mechanisms for advancing or
`retracting the first rod. In some embodiments, such mecha-
`nisms comprisesa first rotational actuation member to which
`the first rod is attached so thatrotation ofthe first rotational
`actuation member advances or
`retracts the first
`rod.
`Typically, another rod is attached to the first rotational
`actuation memberin a position diametrically opposite to the
`first rod so that rotation of the first rotational actuation
`member simultaneously advancesthe first rod and retracts
`the diametrically opposite rod. In some embodiments, the
`tool base further comprises a second rotational actuation
`memberto which the second rodis attached so that rotation
`of the second rotational actuation member advances or
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`tip the base througha first angle so that the distal member
`retracts the second rod substantially along the axial direc-
`faces a first articulated direction. Manipulating typically
`tion. Again, another rod is often attached to the second
`rotational actuation member in a position diametrically
`comprises advancing or retracting the first rod. As previ-
`opposite to the second rod so that rotation of the second
`ously mentioned, advancing or retracting may comprise
`rotational actuation member simultaneously advances the
`rotatingafirst rotational actuation memberto whichthefirst
`second rod andretracts the diametrically opposite rod. Thus,
`rod is attached. Likewise, actuating the wrist may further
`by rotating the first and second rotational actuation
`comprises manipulating a secondrod ofthe plurality of rods
`members,the distal memberis tipped through two angles,or
`to tip the base through a second angle so that the distal
`a compound angle, so that the distal member faces any
`memberfaces a secondarticulated direction. Again, advanc-
`desired direction. This allows refined control of the end
`ing or retracting may comprise rotating a second rotational
`actuation member to which the second rod is attached.
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`effector throughout three dimensions.
`The robotic surgicaltool of the present invention mayalso
`include provisions for roll movement. Roll movement is
`achieved by rotating the shaft around its central axis. Since
`the shaft is connected to a guide tube through which the
`plurality of rods pass, rotation of the shaft rotates guide tube
`whichin turn rotates the rods around the central axis which
`
`is parallel to the axial direction. To actuate suchroll, the
`above described tool base comprises a roll pulley which
`rotates the shaft. Since the rods extend through the roll
`pulley and attach to the rotational actuation members, such
`rotation is possible by flexing of the rods. Due to the length,
`thickness and flexibility of the rods, 360 degree rotation is
`possible. Thus, pitch, yaw and roll movementcan be indi-
`vidually actuated by the tool base, particularly by manipu-
`lation of the rotational actuation members and roll pulley.
`Althoughactuation of the wrist mechanismis achieved by
`manipulation of the rods, it is the connection of the rods to
`the base which allowstipping and manipulation ofthe distal
`member to face a desired direction. Such connection is
`achieved with the use ofa pluralityof linkages, each linkage
`connecting oneofthe plurality of rods with the base. In some
`cmbodiments,
`the linkages comprise orthogonal
`linkage
`assemblies. Each orthogonal
`linkage assembly rotatably
`connects one of the plurality of rods with the base to allow
`the base to be rotated in at least two directions with respect
`to the axial direction. In some embodiments, each orthogo-
`nal linkage assembly comprises an orthogonal linkage hav-
`ing a first link portion which is rotatably connectable with
`the one of the plurality of rods and a second link portion
`whichis rotatably connectable with the base and wherein the
`first link portion and the secondlink portion lie in orthogonal
`planes.
`In other embodiments, each orthogonal
`linkage
`assembly comprises a linkage fastener having a link base
`portion which is rotatably connectable with one of the
`plurality of rods and a cylindrical fastening end portion
`whichis rotatably connectable with the base. The different
`orthogonallinkage assemblies allow the baseto berotated to
`different degrees of angularity relative to the axial direction.
`Such rotation is assisted by flexibility of the rods.
`Generally, each rod is flexible in at least one direction. For
`example, when each rod has a rectangular cross-section,
`having a wideside and a narrowside, the rod maybeflexible
`along the wide side yet rigid along the narrow side. When
`the rods are arranged so that the wide sides are parallel to the
`perimeterofthe shaft, flexibility along the wide sides allows
`each rod to bend slightly inward, toward the center of the
`shaft or the longitudinal axis. This allowsgreater rotation of
`the distal member and flexibility in design parameters.
`In a third aspect of the present invention, methods of
`actuating the robotic surgical tool are provided. In some
`embodiments, methods include providing a robotic surgical
`tool comprising a wrist mechanism, which includesa distal
`member coupleable with a surgical end effector and having
`a base anda plurality of rods rotatably connected to the base
`and extending along an axial direction, and actuating the
`wrist by manipulating a first rod of the plurality of rods to
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`In some embodiments, methods further comprise actuat-
`ing the wrist by rotating the plurality of rods around a
`longitudinal axis parallel to the axial direction to rotate the
`base. In some embodiments, rotating the plurality of rods
`comprises rotating a roll pulley through which the plurality
`of rods extend. And, lastly, methods may further comprise
`coupling the end effector to the base and actuating the end
`effector.
`
`Other objects and advantagesof the present invention will
`become apparent from the detailed description to follow,
`together with the accompanying drawings.
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a perspective overall view of an embodiment of
`the surgical tool of the present invention.
`FIGS. 2A-2Billustrate exemplary surgical end effectors.
`FIG. 3 illustrates an embodiment of a wrist mechanism.
`
`FIGS. 3A-3B illustrate possible arrangements of guide
`slots within the guide tube.
`FIGS. 3C-3D illustrate connection of rods to the distal
`
`membervia orthogonal linkages.
`FIG. 4 illustrates movement of the wrist mechanism
`through a compound angle.
`FIG. 5 illustrates tipping in a variety of directions includ-
`ing a combinations of pitch and yaw.
`FIGS. 6A—6F illustrate three different embodiments of the
`wrist mechanism of the present invention.
`FIG. 7 illustrates assemblage of the first main embodi-
`ment of the wrist mechanism.
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`FIGS. 8-9 illustrate joining of a rod with an orthogonal
`linkage and then joining of the linkage with a foot on the
`distal clevis.
`
`FIG. 10 illustrates joining of additional rods to the distal
`clevis.
`FIG. 11A illustrates the first main embodimentof the wrist
`mechanism wherein four rods are attached.
`FIG. 11B is a cross-sectional view of FIG. 11A.
`
`FIG. 12 illustrates assemblage of the second main
`embodiment of the wrist mechanism.
`
`FIG. 13 illustrates joining of a rod with a linkage fastener
`and for later joining with a distal clevis half.
`FIG. 14 illustrates joining rods with corresponding aper-
`tures on the first and second clevis halves with the use of
`linkage fasteners.
`FIGS. 15-16 show mating ofthe clevis halves and joining
`with a clevis tip.
`FIG. 17Aillustrates the second main embodimentof the
`wrist mechanism wherein four rods are attached.
`FIG. 17Bis a cross-sectional view of FIG. 17A.
`
`FIG. 18 is a perspective view of an embodimentof the
`wrist mechanism showing rods inserted through a guide
`tube.
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`US 6,699,235 B2
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`of feet 18 with apertures 17 which are connected to the
`orthogonal linkages 16. There are at least three rods, and
`more desirably four rods 14 as shownin FIG. 3. The rods 14
`extend through a guide tube 20 within the shaft 52 (not
`shownin FIG. 3) which guides and supports the rods 14.
`FIG. 3A showsthe guide tube 20 having four guide slots 30
`for receiving the four rods 14. FIG. 3B showsa guide tube
`20' having three guide slots 30' for receiving three rods in a
`different embodiment. The guide slots 30 or 30' are evenly
`distributed in a generallycircular pattern to allow the rods 14
`to manipulate and orient the distal member 12 in different
`directions in a generally continuous manner.
`As the rods 14 are slid up and downthe guide slots 30 of
`the guide tube 20, the orthogonal linkages 16 transfer the
`motion to the distal member 12. The rods 14 are configured
`to flex in one plane and be stiff in another plane. In the
`embodiment shown,
`the rods 14 are flattened to have a
`rectangular cross-section with a wide face and a narrow
`width. The rods 14 can flex along the wide face and remain
`stiff along the narrow width. Referring to FIGS. 3A—3B, the
`rods 14 can flex toward or awayfrom the center or central
`axis of the guide tube 20, 20' but remain stiff in terms of
`side-to-side movementalong the perimeter of the guide tube
`20, 20°.
`The rods 14 include apertures 19 near their distal ends
`which connect the rods 14 to the distal member 12 via
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`orthogonal linkages 16. Each orthogonal linkage 16 has a
`first link portion 22 and a second link portion 24 which are
`oriented in an orthogonal manner, as illustrated in FIGS.
`3C-3D. Thefirst link portion 22 includes a first aperture and
`the second link portion 24 includes a second aperture which
`is perpendicular in orientation with respect
`to the first
`aperture. The second link portion 24 is rotatably coupled to
`FIG. 1 illustrates a surgical tool 50 of the present inven-
`the distal end of the rod 14 by a fastener 26 extending
`tion which is used in robotic surgery systems. The surgical
`through the apertures of the second link portion 24 and the
`tool 50 includes a rigid shaft 52 having a proximal end 54,
`distal end of the rod 14. The first link portion 22 is rotatably
`a distal end 56 and a longitudinal axis therebetween. The
`coupled to the feet 18 of the distal member 12 by a fastener
`proximal end 54 is coupled to a tool base 62. ‘Ihe tool base
`28 extending throughthe aperturesofthe first link portion 22
`62 includes an interface 64 which mechanically and elec-
`and the feet 18. Because each orthogonallinkage 16 allows
`trically couples the tool 50 to a manipulator on the robotic
`relative movement between the rod 14 and the distal mem-
`arm cart. A distal member, in this embodimenta distal clevis
`ber 12 in two orthogonal directions, the distal member 12
`58, is coupled to shaft 52 by a wrist joint or wrist mechanism
`can be articulated to move continuously to have orientation
`10, the wrist mechanism 10 providing the distal clevis 58
`in a wide range of angles(in roll, pitch, and yaw) relative to
`with at least 1 degree of freedom and ideally providing at
`the axial direction of the guide tube 20.
`least 3 degrees of freedom. The distal clevis 58 supports a
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`the actual working part that issurgical end effector 66, Whenafirst rod is extended generally along the axial
`
`manipulable for effecting a predetermined treatment of a
`direction, the distal memberor clevis will be tipped through
`target tissue. Exemplary surgical end effectors 66 are illus-
`a first angle. Likewise, when a second rod is extended
`trated in FIGS. 2A-2B. Grasping jaws 70 are illustrated in
`generally along the axial direction, the distal member or
`FIG. 2A, while a cautery isolation effector 72 is illustrated
`clevis will be tipped through a second angle creating a
`in FIG. 2B. It may be appreciated howeverthat anysuitable
`compoundangle. An example of this movement is shown in
`end effector 66 may be used, such as DeBakey forceps,
`a simplified illustration in FIG. 4. Here, distal clevis 58 is
`
`microforceps, Potts scissors, clip appliers, scalpels or elec- shown in dashed line having been tipped throughafirst
`trocautery probes, to name a few. The end effectors 66 can
`angle 39 so that
`the clevis 58 faces a first articulated
`be permanently attached or be removable and optionally
`direction 41. For clarity, the axial direction 37 is aligned
`replaceable with a different type of end effector 66 depend-
`with the y-axis and the first articulated direction 41 aligned
`ing on the surgical need.
`with the z-axis so that the first angle 39 is formed in a y-z
`plane. The distal clevis 58 is then tipped through a second
`The end effector 66 is manipulated by the wrist mecha-
`angle 43 so that the clevis 58 faces a second articulated
`nism 10 to provide the ability of continuous movementin a
`direction 45. ‘The second angle 43 is formedin an x-z plane.
`wide range of angles (in roll, pitch and yaw)relative to an
`In this illustration,the first angle 39 represents the pitch and
`axial direction or the longitudinal axis 51 of the shaft 52. An
`embodiment of the wrist mechanism 10 is illustrated in
`the second angle 43 represents the yaw.
`Generally, the range of angles through which the distal
`member 12 can be articulated varies depending on the
`combination of pitch and yaw movement. For example, FIG.
`5 illustrates a top view of the distal member 12 showing a
`first rod connection point 500, a second rod connection point
`502, a third rod connection point 504 and a fourth ro