Articulate wrist with flexible central member

An articulable wrist for an end effector includes a distal linkage provided at a distal end of the articulable wrist, a proximal linkage provided at a proximal end of the articulable wrist, and a central channel cooperatively defined by the distal and proximal linkages and extending between the distal and proximal ends. A flexible member is arranged within the central channel and has a first end operatively coupled to the distal linkage and a second end axially movable relative to the proximal linkage. One or more conduits are defined in the flexible member to receive one or more central actuation members extending through the flexible member.

BACKGROUND

Minimally invasive surgical (MIS) instruments are often preferred over traditional open surgical devices due to reduced post-operative recovery time and minimal scarring. Laparoscopic surgery is one type of MIS procedure in which one or more small incisions are formed in the abdomen of a patient and a trocar is inserted through the incision to form a pathway that provides access to the abdominal cavity. Through the trocar, a variety of instruments and surgical tools can be introduced into the abdominal cavity. The instruments and tools introduced into the abdominal cavity via the trocar can be used to engage and/or treat tissue in a number of ways to achieve a diagnostic or therapeutic effect.

Various robotic systems have recently been developed to assist in MIS procedures. Robotic systems can allow for more instinctive hand movements by maintaining natural eye-hand axis. Robotic systems can also allow for more degrees of freedom in movement by including an articulable “wrist” joint that creates a more natural hand-like articulation. In such systems, an end effector positioned at the distal end of the instrument can be articulated (moved) using a cable driven motion system having one or more drive cables (or other elongate members) that extend through the wrist joint. A user (e.g., a surgeon) is able to remotely operate the end effector by grasping and manipulating in space one or more controllers that communicate with a tool driver coupled to the surgical instrument. User inputs are processed by a computer system incorporated into the robotic surgical system, and the tool driver responds by actuating the cable driven motion system. Moving the drive cables articulates the end effector to desired angular positions and configurations.

As the wrist joint articulates, drive cables and other elongate members that pass through the wrist joint change length as they are stretched in tension or slackened, depending on the degree of articulation and the offset of the drive cable from the central axis. Upon articulation, for example, drive cables closer to the top of the articulated curvature (e.g., most convex section of the wrist) may be stretched and extended in tension, while drive cables angularly opposite closer to the bottom of the articulated curvature (e.g., most concave section of the wrist) may be slackened. Changing the lengths of the drive cables or other elongate members introduces unpredictability of the true location of each drive cable, which can affect efficient operation of the end effector.

DETAILED DESCRIPTION

The present disclosure is related to robotic surgical systems and, more particularly, to end effectors with articulable wrists that include a flexible member extending through the articulable wrists and accommodating one or more central actuation members.

Embodiments described herein disclose surgical tools that may include a drive housing, an elongate shaft that extends from the drive housing, and an end effector arranged at an end of the elongate shaft. An articulable wrist may interpose the end effector and the elongate shaft and may including a distal linkage provided at a distal end of the articulable wrist and operatively coupled to the end effector, and a proximal linkage provided at a proximal end of the articulable wrist and operatively coupled to the elongate shaft. A central channel may be cooperatively defined by the distal and proximal linkages and extend between the distal and proximal ends. A flexible member may be arranged within the central channel and may have a first end operatively coupled to the distal linkage and a second end axially movable relative to the proximal linkage. One or more central actuation members may extend from the drive housing and through the flexible member via one or more conduits (i.e., lumens) defined in the flexible member. As the wrist articulates, the flexible member may be able to correspondingly bend or flex, and the central actuation members will correspondingly move in the direction of articulation and thereby lengthen or shorten.

Incorporation of the flexible member having defined conduits to guide the central actuation members (e.g., drive cables) creates distinct and repeatable pathways thus improving the ability to predict cable length and location. Just as the cables change length with articulation so will the flexible member. Constraint of both ends of the flexible member during articulation would put it in compression which may cause kinking or obstruction of the inner conduits that may restrict the movement of the drive cables. Fixing one end of the flexible member and allowing the opposite end to translate longitudinally along the shaft axis enables the flexible member to move relative to the articulation joints thus keeping the integrity of the inner conduits intact. Moreover, fixing the flexible member at or near the distal end of the wrist, however, effectively provides a fixed and known location where the central actuation members exit the wrist.

FIG. 1is a block diagram of an example robotic surgical system100that may incorporate some or all of the principles of the present disclosure. As illustrated, the system100can include at least one set of user input controllers102aand at least one control computer104. The control computer104may be mechanically and/or electrically coupled to a robotic manipulator and, more particularly, to one or more robotic arms106(alternately referred to as “tool drivers”). In some embodiments, the robotic manipulator may be included in or otherwise mounted to an arm cart capable of making the system portable. Each robotic arm106may include and otherwise provide a location for mounting one or more surgical instruments or tools108for performing various surgical tasks on a patient110. Operation of the robotic arms106and associated tools108may be directed by a clinician112a(e.g., a surgeon) from the user input controller102a.

In some embodiments, a second set of user input controllers102b(shown in dashed lines) may be operated by a second clinician112bto direct operation of the robotic arms106and tools108in conjunction with the first clinician112a. In such embodiments, for example, each clinician112a,bmay control different robotic arms106or, in some cases, complete control of the robotic arms106may be passed between the clinicians112a,b. In some embodiments, additional robotic manipulators (not shown) having additional robotic arms (not shown) may be utilized during surgery on the patient110, and these additional robotic arms may be controlled by one or more of the user input controllers102a,b.

The control computer104and the user input controllers102a,bmay be in communication with one another via a communications link114, which may be any type of wired or wireless telecommunications means configured to carry a variety of communication signals (e.g., electrical, optical, infrared, etc.) according to any communications protocol. In some applications, for example, there is a tower with ancillary equipment and processing cores designed to drive the robotic arms106.

The user input controllers102a,bgenerally include one or more physical controllers that can be grasped by the clinicians112a,band manipulated in space while the surgeon views the procedure via a stereo display. The physical controllers generally comprise manual input devices movable in multiple degrees of freedom, and which often include an actuatable handle for actuating the surgical tool(s)108, for example, for opening and closing opposing jaws, applying an electrical potential (current) to an electrode, or the like. The control computer104can also include an optional feedback meter viewable by the clinicians112a,bvia a display to provide a visual indication of various surgical instrument metrics, such as the amount of force being applied to the surgical instrument (i.e., a cutting instrument or dynamic clamping member).

FIG. 2is an isometric side view of an example surgical tool200that may incorporate some or all of the principles of the present disclosure. The surgical tool200may be the same as or similar to the surgical tool(s)108ofFIG. 1and, therefore, may be used in conjunction with a robotic surgical system, such as the robotic surgical system100ofFIG. 1. Accordingly, the surgical tool200may be designed to be releasably coupled to a tool driver included in the robotic surgical system100. In other embodiments, however, aspects of the surgical tool200may be adapted for use in a manual or hand-operated manner, without departing from the scope of the disclosure.

As illustrated, the surgical tool200includes an elongated shaft202, an end effector204, a wrist206(alternately referred to as a “wrist joint” or an “articulable wrist joint”) that couples the end effector204to the distal end of the shaft202, and a drive housing208coupled to the proximal end of the shaft202. In applications where the surgical tool is used in conjunction with a robotic surgical system (e.g., the robotic surgical system100ofFIG. 1), the drive housing208can include coupling features that releasably couple the surgical tool200to the robotic surgical system.

The terms “proximal” and “distal” are defined herein relative to a robotic surgical system having an interface configured to mechanically and electrically couple the surgical tool200(e.g., the housing208) to a robotic manipulator. The term “proximal” refers to the position of an element closer to the robotic manipulator and the term “distal” refers to the position of an element closer to the end effector204and thus further away from the robotic manipulator. Alternatively, in manual or hand-operated applications, the terms “proximal” and “distal” are defined herein relative to a user, such as a surgeon or clinician. The term “proximal” refers to the position of an element closer to the user and the term “distal” refers to the position of an element closer to the end effector204and thus further away from the user. Moreover, the use of directional terms such as above, below, upper, lower, upward, downward, left, right, and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward or upper direction being toward the top of the corresponding figure and the downward or lower direction being toward the bottom of the corresponding figure.

During use of the surgical tool200, the end effector204is configured to move (pivot) relative to the shaft202at the wrist206to position the end effector204at desired orientations and locations relative to a surgical site. To accomplish this, the housing208includes (contains) various drive inputs and mechanisms (e.g., gears, actuators, etc.) designed to control operation of various features associated with the end effector204(e.g., clamping, firing, rotation, articulation, cutting, etc.). In at least some embodiments, the shaft202, and hence the end effector204coupled thereto, is configured to rotate about a longitudinal axis A1of the shaft202. In such embodiments, at least one of the drive inputs included in the housing208is configured to control rotational movement of the shaft202about the longitudinal axis A1.

The surgical tool200can have any of a variety of configurations capable of performing at least one surgical function. For example, the surgical tool200may include, but is not limited to, forceps, a grasper, a needle driver, scissors, an electro cautery tool, a stapler, a clip applier, a hook, a spatula, a suction tool, an irrigation tool, an imaging device (e.g., an endoscope or ultrasonic probe), or any combination thereof. In some embodiments, the surgical tool200may be configured to apply energy to tissue, such as radio frequency (RF) energy.

The shaft202is an elongate member extending distally from the housing208and has at least one lumen extending therethrough along its axial length. In some embodiments, the shaft202may be fixed to the housing208, but could alternatively be rotatably mounted to the housing208to allow the shaft202to rotate about the longitudinal axis A1. In yet other embodiments, the shaft202may be releasably coupled to the housing208, which may allow a single housing208to be adaptable to various shafts having different end effectors.

The end effector204can have a variety of sizes, shapes, and configurations. In the illustrated embodiment, the end effector204comprises a tissue grasper and vessel sealer that include opposing jaws210,212configured to move (articulate) between open and closed positions. As will be appreciated, however, the opposing jaws210,212may alternatively form part of other types of end effectors such as, but not limited to, a surgical scissors, a clip applier, a needle driver, a babcock including a pair of opposed grasping jaws, bipolar jaws (e.g., bipolar Maryland grasper, forceps, a fenestrated grasper, etc.), etc. One or both of the jaws210,212may be configured to pivot to articulate the end effector204between the open and closed positions. It is noted, however, that the principles of the present disclosure are equally applicable to an end effector that does not include opposing jaws.

FIG. 3illustrates the potential degrees of freedom in which the wrist206may be able to articulate (pivot). The wrist206can have any of a variety of configurations. In general, the wrist206comprises a joint configured to allow pivoting movement of the end effector204relative to the shaft202. The degrees of freedom of the wrist206are represented by three translational variables (i.e., surge, heave, and sway), and by three rotational variables (i.e., Euler angles or roll, pitch, and yaw). The translational and rotational variables describe the position and orientation of a component of a surgical system (e.g., the end effector204) with respect to a given reference Cartesian frame. As depicted inFIG. 3, “surge” refers to forward and backward translational movement, “heave” refers to translational movement up and down, and “sway” refers to translational movement left and right. With regard to the rotational terms, “roll” refers to tilting side to side, “pitch” refers to tilting forward and backward, and “yaw” refers to turning left and right.

The pivoting motion can include pitch movement about a first axis of the wrist206(e.g., X-axis), yaw movement about a second axis of the wrist206(e.g., Y-axis), and combinations thereof to allow for 360° rotational movement of the end effector204about the wrist206. In other applications, the pivoting motion can be limited to movement in a single plane, e.g., only pitch movement about the first axis of the wrist206or only yaw movement about the second axis of the wrist206, such that the end effector204moves only in a single plane.

Referring again toFIG. 2, the surgical tool200may also include a plurality of drive cables (obscured inFIG. 2) that form part of a cable driven motion system configured to facilitate movement and articulation of the end effector204relative to the shaft202. Moving (actuating) at least some of the drive cables moves the end effector204between an unarticulated position and an articulated position. The end effector204is depicted inFIG. 2in the unarticulated position where a longitudinal axis A2of the end effector204is substantially aligned with the longitudinal axis A1of the shaft202, such that the end effector204is at a substantially zero angle relative to the shaft202. Due to factors such as manufacturing tolerance and precision of measurement devices, the end effector204may not be at a precise zero angle relative to the shaft202in the unarticulated position, but nevertheless be considered “substantially aligned” thereto. In the articulated position, the longitudinal axes A1, A2would be angularly offset from each other such that the end effector204is at a non-zero angle relative to the shaft202.

In some embodiments, the surgical tool200may be supplied with electrical power (current) via a power cable214coupled to the housing208. In other embodiments, the power cable214may be omitted and electrical power may be supplied to the surgical tool200via an internal power source, such as one or more batteries or fuel cells. In such embodiments, the surgical tool200may alternatively be characterized and otherwise referred to as an “electrosurgical instrument” capable of providing electrical energy to the end effector204.

The power cable214may place the surgical tool200in communication with a generator216that supplies energy, such as electrical energy (e.g., radio frequency energy), ultrasonic energy, microwave energy, heat energy, or any combination thereof, to the surgical tool200and, more particularly, to the end effector204. Accordingly, the generator216may comprise a radio frequency (RF) source, an ultrasonic source, a direct current source, and/or any other suitable type of electrical energy source that may be activated independently or simultaneously.

In applications where the surgical tool200is configured for bipolar operation, the power cable214will include a supply conductor and a return conductor. Current can be supplied from the generator216to an active (or source) electrode located at the end effector204via the supply conductor, and current can flow back to the generator216via a return electrode located at the end effector204via the return conductor. In the case of a bipolar grasper with opposing jaws, for example, the jaws serve as the electrodes where the proximal end of the jaws are isolated from one another and the inner surface of the jaws (i.e., the area of the jaws that grasp tissue) apply the current in a controlled path through the tissue. In applications where the surgical tool200is configured for monopolar operation, the generator216transmits current through a supply conductor to an active electrode located at the end effector204, and current is returned (dissipated) through a return electrode (e.g., a grounding pad) separately coupled to a patient's body.

FIG. 4is an enlarged isometric view of the distal end of the surgical tool200ofFIG. 2. More specifically,FIG. 4depicts an enlarged view of the end effector204and the wrist206, with the jaws210,212of the end effector204in the open position. The wrist206operatively couples the end effector204to the shaft202. In some embodiments, however, a shaft adapter may be directly coupled to the wrist206and otherwise interpose the shaft202and the wrist206. Accordingly, the wrist206may be operatively coupled to the shaft202either through a direct coupling engagement where the wrist206is directly coupled to the distal end of the shaft202, or an indirect coupling engagement where a shaft adapter interposes the wrist206and the distal end of the shaft202. As used herein, the term “operatively couple” refers to a direct or indirect coupling engagement between two components.

To operatively couple the end effector204to the shaft202, the wrist206includes a first or “distal” linkage402a, a second or “intermediate” linkage402b, and a third or “proximal” linkage402c. The linkages402a-care configured to facilitate articulation of the end effector204relative to the elongate shaft202, e.g., angle the end effector204relative to the longitudinal axis A1of the shaft202. In the illustrated embodiment, articulation via the linkages402a-cmay be limited to pitch only, yaw only, or a combination thereof. As illustrated, the distal end of the distal linkage402amay be coupled to the end effector204and, more particularly, to the lower jaw212(or an extension of the lower jaw212). The proximal end of the distal linkage402amay be rotatably coupled to the intermediate linkage402bat a first axle404a, and the intermediate linkage402bmay also be rotatably coupled to the proximal linkage402cat a second axle404b. The proximal end of the proximal linkage402cmay be coupled to a distal end406of the shaft202(or alternatively a shaft adapter).

The wrist206provides a first pivot axis P1that extends through the first axle404aand a second pivot axis P2that extends through the second axle404b. The first pivot axis P1is substantially perpendicular (orthogonal) to the longitudinal axis A2of the end effector204, and the second pivot axis P2is substantially perpendicular (orthogonal) to both the longitudinal axis A2and the first pivot axis P1. Movement about the first pivot axis P1provides “yaw” articulation of the end effector204, and movement about the second pivot axis P2provides “pitch” articulation of the end effector204. Alternatively, the first pivot axis P1could be configured to provide “pitch” articulation and the second pivot axis P2could be configured to provide “yaw” articulation.

A plurality of drive cables, shown as drive cables408a,408b,408c, and408d, extend longitudinally within a lumen410defined by the shaft202(and/or a shaft adaptor) and pass through the wrist206to be operatively coupled to the end effector204. The lumen410can be a single lumen, as illustrated, or can alternatively comprise a plurality of independent lumens, where each lumen receives one or more of the drive cables408a-d.

The drive cables408a-dform part of the cable driven motion system briefly described above, and may be referred to and otherwise characterized as cables, bands, lines, cords, wires, woven wires, ropes, strings, twisted strings, elongate members, etc. The drive cables408a-dcan be made from a variety of materials including, but not limited to, metal (e.g., tungsten, stainless steel, etc.) a polymer (e.g., ultra-high molecular weight polyethylene), a synthetic fiber (e.g., KEVLAR®, VECTRAN®, etc.), or any combination thereof. While four drive cables408a-dare depicted inFIG. 4, more or less than four drive cables408a-dmay be included, without departing from the scope of the disclosure.

The drive cables408a-dextend proximally from the end effector204to the drive housing208(FIG. 2) where they are operatively coupled to various actuation mechanisms (e.g., capstans) or devices housed therein to facilitate longitudinal movement (translation) of the drive cables408a-dwithin the lumen410. Selective actuation of all or a portion of the drive cables408a-dcauses the end effector204to articulate (pivot) relative to the shaft202. More specifically, selective actuation causes a corresponding drive cable408a-dto translate longitudinally within the lumen410and thereby cause pivoting movement of the end effector204. Moving the drive cables408a-dcan be accomplished in a variety of ways, such as by triggering an associated actuator or mechanism (e.g., a capstan) operatively coupled to or housed within the drive housing208(FIG. 2). Moving a given drive cable408a-dconstitutes applying tension (i.e., pull force) to the given drive cable408a-din a proximal direction, which causes the given drive cable408a-dto translate and thereby cause the end effector204to move (articulate) relative to the shaft202. As will be appreciated, applying tension to and moving one drive cable408a-dmay result in the slackening of a drive cable402a-dangularly (or diagonally) opposite to the moving drive cable402a-d.

The drive cables408a-deach extend longitudinally through the first, second, and third linkages402a-c. In some embodiments, each linkage402a-cmay define four, equidistantly-spaced apertures412(only two labeled) configured to guide the drive cables408a-dthrough the wrist206. The apertures412of each linkage402a-cmay coaxially align when the end effector204is in the unarticulated position. The apertures412may provide rounded edges and sufficiently large radii to help reduce friction between the drive cables408a-dand the linkages402a-cand/or help prevent the drive cables408a-dfrom twisting or moving radially inward or outward during articulation.

In some embodiments, the distal end of each drive cable408a-dmay terminate at the distal linkage402a, thus operatively coupling each drive cable408a-dto the end effector204and, more particularly, to the lower jaw212. The distal end of each drive cable408a-dmay be enlarged to facilitate fixed attachment thereof to the end effector204. In some embodiments, as illustrated, the distal end of each drive cable408a-dmay include a ball crimp413(only one shown). In other embodiments, however, the distal end of each drive cable408a-dmay include a weld, an adhesive attachment, a press fit, or any combination of the foregoing.

The jaws210,212may be moved between the closed and open positions by pivoting the upper jaw210relative to the lower jaw212. In the illustrated embodiment, the upper jaw210may be rotatably coupled (mounted) to the lower jaw212at a jaw axle414. A third pivot axis P3extends through the jaw axle414and is generally perpendicular (orthogonal) to the first pivot axis P1and parallel to the second pivot axis P2. In this embodiment, the lower jaw212remains stationary as the upper jaw210pivots about the third pivot axis P3. In other embodiments, however, the jaws210,212may be moved between the closed and open positions by moving (pivoting) both jaws210,212, without departing from the scope of the disclosure.

A central pulley416(partially visible) may be mounted to the jaw axle414and receive a jaw cable418that may be actuated to selectively open and close the jaws210,212. Similar to the drive cables408a-d, the jaw cable418extends longitudinally within the lumen410and passes through the wrist206. The jaw cable418may form part of the cable driven motion system described herein and, therefore, may extend proximally from the end effector204to the drive housing208(FIG. 2). The jaw cable418may comprise a single line or wire looped around the central pulley416and opposing first and second ends420aand420bof the jaw cable418extend proximally to the drive housing208. The ends420a,bof the jaw cable418may be operatively coupled to individual (discrete) actuation mechanisms (e.g., two capstans) housed within the drive housing208. Actuation of corresponding drive inputs associated with each actuation mechanism will cooperatively cause tension or slack in the jaw cable418and thereby cause the upper jaw210to rotate about the third pivot axis P3between the open and closed positions.

In some embodiments, an electrical conductor422may supply electrical energy to the end effector204and, more particularly, to an electrode424included in the end effector204. The electrical conductor422extends longitudinally within the lumen410, through the wrist206, and terminates at the electrode424. In the illustrated embodiment, the electrode424is mounted to (e.g., overmolded onto) or otherwise forms part of the lower jaw212. In other embodiments, however, the electrode424may form part of the upper jaw210, or may alternatively be coupled to or form part of both jaws210,212, without departing from the scope of the disclosure. In some embodiments, the electrical conductor422and the power cable214(FIG. 2) may comprise the same structure. In other embodiments, however, the electrical conductor422may be electrically coupled to the power cable214, such as at the drive housing208(FIG. 2). In yet other embodiments, the electrical conductor422may extend to the drive housing208where it is electrically coupled to an internal power source, such as batteries or fuel cells.

In some embodiments, the electrical conductor422may comprise a wire. In other embodiments, however, the electrical conductor422may comprise a rigid or semi-rigid shaft, rod, or strip (ribbon) made of a conductive material. The electrical conductor422may be partially covered with an insulative covering (overmold) made of a non-conductive material. The insulative covering, for example, may comprise a plastic applied to the electrical conductor422via heat shrinking, but could alternatively be any other non-conductive material.

The end effector204may be configured for monopolar or bipolar operation. In at least one embodiment, the electrical energy conducted through the electrical conductor422may comprise radio frequency (“RF”) energy exhibiting a frequency between about 100 kHz and 1 MHz. In a process known as Joule heating (resistive or Ohmic heating) the RF energy is transformed into heat within the target tissue due the tissue's intrinsic electrical impedance, thereby increasing the temperature of target tissue. Accordingly, heating of the target tissue is used to achieve various tissue effects such as cauterization and/or coagulation and thus may be particularly useful for sealing blood vessels or diffusing bleeding during a surgical procedure.

In the illustrated embodiment, the end effector204comprises a combination tissue grasper and vessel sealer that includes a cutting element426(mostly occluded), alternately referred to as a “knife” or “blade.” The cutting element426is aligned with and configured to traverse a guide track428(alternately referred to as a “defined” or “structured” pathway) defined longitudinally in one or both of the upper and lower jaws210,212. The cutting element426may be operatively coupled to the distal end of a drive rod430(alternately referred to as a “knife rod,” “actuation rod,” or “cutting rod”) that extends longitudinally within the lumen410and passes through the wrist206. Longitudinal movement (translation) of the drive rod430correspondingly moves the cutting element426within the guide track(s)428in the same direction.

The drive rod430may comprise a rigid or semi rigid elongate member, such as a rod or shaft (e.g., a hypotube, a hollow rod, a solid rod, etc.), a wire, a ribbon, a push cable, or any combination thereof. The drive rod430can be made from a variety of materials including, but not limited to, metal (e.g., tungsten, stainless steel, nitinol, etc.), a polymer, a composite material, or a combination thereof. The drive rod430may have a circular cross-section, but may alternatively exhibit a polygonal cross-section without departing from the scope of the disclosure.

Similar to the drive and jaw cables408a-d,418, the drive rod430may form part of the cable driven motion system and, therefore, may extend proximally from the cutting element426to the drive housing208(FIG. 2). The proximal end of the drive rod430may be operatively coupled to an actuation mechanism or device housed within the drive housing208. Selective actuation of the corresponding drive input associated with the actuation mechanism or device will cause the drive rod430to move distally or proximally within the lumen410, and correspondingly move the cutting element426in the same direction.

FIG. 5is an isometric side view of the end effector204in an open position, according to one or more embodiments. More particularly,FIG. 5depicts the upper jaw210pivoted to the open position, and the lower jaw212(FIG. 4) is omitted to enable viewing of the internal components of the end effector204. As illustrated, the end effector204includes a pivot link502operatively coupled to the upper jaw210. More specifically, the upper jaw210provides or otherwise defines one or more legs504(one shown, one occluded) that are pivotably coupled to a corresponding one or more legs506(one shown, one occluded) of the pivot link502at a pivot axle508. A fourth pivot axis P4extends through the pivot axle508and may be generally perpendicular (orthogonal) to the first pivot axis P1and parallel to the second and third pivot axes P2, P3.

The central pulley416(mostly occluded) is rotatably supported on the jaw axle414, and the jaw cable418loops around the central pulley416and includes opposing ends420a,bthat extend proximally through the wrist206. The jaw cable418may be operatively coupled to the pivot link502such that movement (i.e., longitudinal translation) of the jaw cable418correspondingly moves the pivot link502. For example, a cable anchor510may be secured to or otherwise form part of one proximally extending end420a,bof the jaw cable418and may help operatively couple the jaw cable418to the pivot link502. In the illustrated embodiment, the cable anchor510comprises a ball crimp attached to the first end420aand receivable within a socket defined by the pivot link502. In other embodiments, however, the cable anchor510may alternatively include, but is not limited to, a weld, an adhesive attachment, a press fit engagement, or any combination of the foregoing and capable of being removably or permanently attached to the pivot link502.

To move the jaws210,212to the open position, the jaw cable418may be actuated to move the pivot link502distally, which may be done, for example, by pulling proximally on the second end420bof the jaw cable418(alternately referred to as the “open cable”). As the pivot link502moves distally, the legs506of the pivot link502act on the legs504of the upper jaw210at the pivot axle508. Distal movement of the pivot link502forces the legs504downward in rotation about the fourth pivot axis P4, and downward movement of the legs504correspondingly causes the upper jaw210to pivot about the third pivot axis P3, similar to the operation of a two-bar linkage. As it pivots about the third pivot axis P3, the upper jaw210is moved to the open position.

To move the upper jaw210back to the closed position, the jaw cable418may be actuated to move the pivot link502proximally, which may be done, for example, by pulling proximally on the first end420aof the jaw cable418(alternately referred to as the “closure cable”). This causes the pivot link502to pull upward on the legs504of the upper jaw210in rotation about the fourth pivot axis P4, and upward movement of the legs504correspondingly causes the upper jaw210to pivot about the third pivot axis P3and moves the upper jaw210back to the closed position.

In the illustrated embodiment, the end effector204may further include a longitudinal support structure512(partially colluded) that supports the drive rod430against buckling. As the cutting element426is advanced distally within the guide track(s)428to transect tissue grasped by the closed jaws210,212, the tissue will generate an opposing force (loading) in the proximal direction that resists distal movement of the cutting element426. If the resistance load of the tissue surpasses the compressive capacity of the drive rod430in the distal direction, the drive rod430may buckle and the cutting operation will be compromised. The longitudinal support structure512may be configured to enhance or supplement the compressive capacity of the drive rod430and thereby mitigate buckling at or near the jaws210,212.

FIGS. 6A and 6Bare enlarged isometric front and back views, respectively, of the wrist206, according to one or more embodiments. The wrist206may have a first or “distal” end602aand a second or “proximal” end602bopposite the distal end602a. The distal linkage402ais positioned at the distal end602a, the proximal linkage402cis positioned at the proximal end602b, and the intermediate linkage402binterposes and operatively couples the distal and proximal linkages402a,c. However, it is noted that embodiments are contemplated herein where the intermediate linkage402bis omitted and the distal and proximal linkages402a,care alternatively directly coupled at a common axle.

The drive cables408a-d, the electrical conductor422, the first and second ends420a,bof the jaw cable418(FIGS. 4 and 5), and the drive rod430are depicted inFIGS. 6A-6Bas dashed lines for simplicity. As illustrated, the drive cables408a-dpass through portions (e.g., apertures412) of the wrist206and terminate at the distal linkage402a. In some embodiments, the proximal linkage402cmay provide or otherwise define one or more longitudinal grooves604to accommodate each drive cable408a-d. As illustrated, each groove604may be configured to receive a corresponding one of the drive cables408a-d. The grooves604may be equidistantly-spaced or non-equidistantly spaced about the outer circumference of the proximal linkage402cand otherwise aligned with the corresponding apertures412defined by the proximal linkage402c. The grooves604may provide rounded edges to help reduce friction on the drive cables408a-dduring operation, and may help prevent the drive cables408a-dfrom twisting or moving radially inward or outward during articulation of the wrist206.

The wrist206may provide or otherwise define a central channel606that extends between the distal and proximal ends602a,b. The electrical conductor422, the first and second ends420a,bof the jaw cable418(FIGS. 4 and 5), and the drive rod430may penetrate the wrist206by extending through the central channel606. In embodiments where the wrist206includes the distal, intermediate, and proximal linkages402a-c, as illustrated, corresponding portions of the central channel606may be cooperatively and successively defined by each linkage402a-c. However, in embodiments where the wrist206includes only the distal and proximal linkages402a,c, the central channel606may be defined cooperatively and successively by only the distal and proximal linkages402a,c. The portions of the central channel606defined by each linkage402a-cmay coaxially align when the wrist206is non-articulated, but may move out of alignment once the wrist206is moved in articulation.

The wrist206may include a flexible member608arranged within the central channel606and extending at least partially between the first and second ends602a-bof the wrist206. As best seen inFIG. 6B, the flexible member608may provide or otherwise define one or more conduits610(four shown) that extend through the entire length of the flexible member608. The conduits610may be configured to receive one or more of the electrical conductor422, the first and second ends420a,bof the jaw cable418(FIGS. 4 and 5), and the drive rod430, collectively referred to herein as “central actuation members.” Accordingly, one or more of the central actuation members may penetrate the wrist206by extending through the conduits610of the flexible member608.

The flexible member608may be operatively coupled to the distal linkage402aat its distal end, but may be free to move axially relative to the proximal linkage402cat its proximal end. In some embodiments, for example, the wrist206may include a distal adapter612(FIG. 6A) and a proximal adapter614(FIG. 6B). The distal adapter612may be configured to operatively couple the flexible member608to the distal linkage402a, and the proximal adapter612may be configured to support the flexible member608in sliding axial engagement with the proximal linkage402c. In at least one embodiment, however, the proximal adapter612may be omitted and the flexible member608may directly contact the proximal linkage402cin sliding engagement.

FIGS. 7A and 7Bare isometric and exploded views, respectively, of the flexible member608and the distal and proximal adapters612,614, according to one or more embodiments. As illustrated, the flexible member608may comprise a generally cylindrical body702having a first or “distal” end704aand a second or “proximal” end704bopposite the distal end704a. In some embodiments, as illustrated, the body702may exhibit a substantially circular cross-section, but may alternatively exhibit other cross-sectional shapes, such as polygonal (e.g., triangular, rectangular, etc.), oval, ovoid, or any combination thereof, without departing from the scope of the disclosure.

The flexible member608may be made of any flexible or semi-flexible material that allows the flexible member608to flex or bend when the wrist206(FIGS. 6A-6B) articulates. The material for the flexible member608may also exhibit low friction characteristics or may otherwise be lubricious, which may prove advantageous in minimizing friction caused by the central actuation members (e.g., the electrical conductor422, the first and second ends420a,bof the jaw cable418, and the drive rod430ofFIGS. 6A-6B) moving within the conduits610. Furthermore, the material for the flexible member608may also exhibit good wear characteristics so the central actuation members do not inadvertently cut through the corresponding conduits610after repeated use. The diameter or size of each conduit610may be large enough to enable the central actuation members to move therein without substantive obstruction (friction), but small enough to support the central actuation members.

Suitable materials for the flexible member608include, but are not limited to, polytetrafluoroethylene (PTFE or TEFLON®), silicone, nylon, polyurethane (e.g., CARBOTHANE™), or any combination thereof. In at least one embodiment, the flexible member608may comprise an extrusion.

The distal adapter612may be made of a rigid or semi-rigid material including, but not limited to, a plastic, a metal, a composite material, and any combination thereof. Suitable materials for the distal adapter612include polyetherimide, polycarbonate, polystyrene, nylon, etc. In some embodiments, as illustrated, the distal adapter612may provide or otherwise define a radial shoulder706and a flange708that extends from the radial shoulder706. The flange708may be sized to receive the distal end704aof the flexible member608. In other embodiments, however, the flange708may be omitted and the distal adapter612may nonetheless be coupled to the flexible member608.

The distal adapter612may be coupled (fixed) to the distal end704aof the flexible member608via a variety of attachment means. Suitable attachment means include, but are not limited to, bonding (e.g., an adhesive), welded (e.g., sonic or ultrasonic welding), overmolding the distal adapter612onto the distal end704a, an interference or shrink fit, or any combination thereof.

The distal adapter612may define one or more or apertures710(four shown) configured to co-axially align with the conduits610of the flexible member608. Accordingly, the central actuation members extending through the flexible member608(e.g., the electrical conductor422, the first and second ends420a,bof the jaw cable418, and the drive rod430ofFIGS. 6A-6B) may each exit the flexible member608at the apertures710of the distal adapter612.

In some embodiments, the distal adapter612may provide one or more features712configured to mate with one or more corresponding features of the distal linkage402a(FIGS. 6A-6B). In the illustrated embodiment, the features712are defined on the flange708, but could alternatively be defined on any other portion of the distal adapter612, without departing from the scope of the disclosure. Mating the features712of the distal adapter612with the corresponding features of the distal linkage402amay help rotationally fix the distal end704aof the flexible member608at the distal end602a(FIGS. 6A-6B) of the wrist206(FIGS. 6A-6B).

The proximal adapter614may be made of a rigid or semi-rigid material including, but not limited to, a plastic, a metal, a composite material, and any combination thereof. Suitable materials for the proximal adapter614include polyetherimide, polycarbonate, polystyrene, nylon, etc. In the illustrated embodiment, the proximal adapter614provides a generally annular body714sized to receive the proximal end704bof the flexible member608. In some embodiments, the proximal end704bmay extend entirely through the annular body714, but may alternatively extend only partially therethrough, without departing from the scope of the disclosure.

The proximal adapter614may be coupled (fixed) to the proximal end704bof the flexible member608via a variety of attachment means. Suitable attachment means include, but are not limited to, bonding (e.g., an adhesive), welded (e.g., sonic or ultrasonic welding), overmolding the proximal adapter614onto the proximal end704b, an interference or shrink fit, or any combination thereof.

In some embodiments, a flange716may extend proximally from the body714of the proximal adapter614. The flange716may provide or define a groove718co-axially alignable with one of the conduits610defined through the flexible member608and sized to receive one of the central actuation members, such as the drive rod430(FIGS. 5 and 6A-6B). The groove718may prove advantageous in helping to prevent buckling of the drive rod430during operation.

In some embodiments, the proximal adapter614may provide one or more features720configured to mate with one or more corresponding features provided by the proximal linkage402c(FIGS. 6A-6B). As discussed in more detail below, the feature720may comprise a longitudinal rib that may be configured to mate with a longitudinal channel of the proximal linkage402c.

Referring again toFIGS. 6A-6B, in some embodiments, the distal adapter612may be partially received within the central channel606defined in the distal linkage402a. More specifically, the flange708(seeFIG. 6B) of the distal adapter612may extend into the central channel606until the radial shoulder706(seeFIG. 6A) of the distal adapter612engages the distal end602aof the wrist206and, more particularly, the distal linkage402a. In some embodiments, one or more features (not shown) may be defined on the inner radial surface of the central channel606at the distal linkage402aand configured to mate with the features712(FIGS. 7A-7B) of the distal adapter612. Mating these features may help rotationally fix the distal adapter612relative to the distal end602a(FIGS. 6A-6B) of the wrist206(FIGS. 6A-6B).

The distal adapter612may be arranged to interpose the lower jaw212(FIG. 4) and the distal linkage402awithin the assembly of the end effector204(FIGS. 4-5), thus restraining (trapping) the distal adapter612between the lower jaw212and the distal linkage402a. Since the distal adapter612may be fixed to the distal end704a(FIGS. 7A-7B) of the flexible member608, restraining (trapping) the distal adapter612between the lower jaw212and the distal linkage402amay correspondingly fix the flexible member608in place at the distal end602aof the wrist206.

Referring specifically toFIG. 6B, the proximal linkage402cmay provide or define a feature618sized and otherwise configured to receive (mate with) the feature720provided by the proximal adapter614. In the illustrated embodiment, the feature618comprises a longitudinal channel, and the feature720comprises a longitudinal rib matable with the longitudinal channel. Mating the features618,720may help rotationally fix the flexible member608to the proximal linkage402c, but also allows the flexible member608to move longitudinally relative to the proximal linkage402c. For example, as the wrist206articulates, the feature720of the proximal adapter614may slide relative to the feature618of the proximal linkage402c. In some embodiments, however, the proximal adapter614may be omitted and the feature720may alternatively be provided by the flexible member608, without departing from the scope of the disclosure. In other embodiments, the flexible member608may be molded or otherwise formed in a shape that lends itself to be rotationally fixed to the proximal linkage402c, such as a square or “D” shape.

In example operation of the wrist206, the drive cables408a-dmay be selectively actuated to cause the wrist206to articulate. As the wrist206articulates, the flexible member608is able to correspondingly bend or flex, and the central actuation members (e.g., the electrical conductor422, the first and second ends420a,bof the jaw cable418, and the drive rod430) will correspondingly move in the direction of articulation and thereby lengthen or shorten, depending on the bend direction of the flexible member608. Extending the central actuation members through the conduits610of the flexible member608creates a defined and predictable pathway for each central actuation member. Moreover, fixing the flexible member608at or near the distal end602aof the wrist206effectively provides a fixed and known location where the central actuation members exit the wrist206. Furthermore, as the wrist206changes articulation positions, the central actuation members correspondingly change length and the flexible member608is able to slide longitudinally relative to the proximal linkage402cat the proximal end602bof the wrist206. The rotationally fixed orientation of the flexible member608helps prevent the central actuation members from twisting, which maintains predictable locations for each central actuation member.

A. An articulable wrist for an end effector that includes a distal linkage provided at a distal end of the articulable wrist, a proximal linkage provided at a proximal end of the articulable wrist, a central channel cooperatively defined by the distal and proximal linkages and extending between the distal and proximal ends, a flexible member arranged within the central channel and having a first end operatively coupled to the distal linkage and a second end axially movable relative to the proximal linkage, and one or more conduits defined in the flexible member to receive one or more central actuation members extending through the flexible member.

B. A surgical tool that includes a drive housing, an elongate shaft that extends from the drive housing, an end effector arranged at an end of the elongate shaft, an articulable wrist that interposes the end effector and the elongate shaft, the articulable wrist including a distal linkage provided at a distal end of the articulable wrist and operatively coupled to the end effector, a proximal linkage provided at a proximal end of the articulable wrist and operatively coupled to the elongate shaft, a central channel cooperatively defined by the distal and proximal linkages and extending between the distal and proximal ends, and a flexible member arranged within the central channel and having a first end operatively coupled to the distal linkage and a second end axially movable relative to the proximal linkage. The surgical tool further including one or more central actuation members extending from the drive housing and through the flexible member via one or more conduits defined in the flexible member.

C. A method of operating a surgical tool that includes positioning the surgical tool adjacent a patient for operation, the surgical tool including a drive housing, an elongate shaft that extends from the drive housing, an end effector arranged at an end of the elongate shaft, and a wrist that interposes the end effector and the elongate shaft and includes a distal linkage provided at a distal end of the wrist and operatively coupled to the end effector, a proximal linkage provided at a proximal end of the wrist and operatively coupled to the elongate shaft, a central channel cooperatively defined by the distal and proximal linkages and extending between the distal and proximal ends, a flexible member arranged within the central channel and having a first end operatively coupled to the distal linkage and a second end axially movable relative to the proximal linkage, and one or more conduits defined in the flexible member to receive one or more central actuation members extending through the flexible member. The method further including articulating the wrist and simultaneously bending the flexible member within the central channel.

Each of embodiments A, B, and C may have one or more of the following additional elements in any combination: Element1: further comprising an intermediate linkage interposing the distal and proximal linkages and defining a portion of the central channel. Element2: wherein the one or more central actuation members are selected from the group consisting of an electrical conductor, first and second ends of a jaw cable, and a drive rod. Element3: further comprising a distal adapter coupled to the first end of the flexible member and engageable with the distal linkage to operatively couple the flexible member to the distal linkage. Element4: wherein the distal adapter provides a flange that receives the first end of the flexible member. Element5: wherein the distal adapter defines one or more or apertures co-axially alignable with the one or more conduits such that the one or more central actuation members also extend through the one or more apertures. Element6: further comprising a proximal adapter coupled to the second end of the flexible member and slidingly engageable with the proximal linkage. Element7: wherein the proximal adapter provides an annular body that receives the second end of the flexible member. Element8: wherein the flexible member comprises a material selected from the group consisting of polytetrafluoroethylene, silicone, nylon, polyurethane, and any combination thereof.

Element9: further comprising an intermediate linkage interposing the distal and proximal linkages and defining a portion of the central channel. Element10: further comprising a distal adapter coupled to the first end of the flexible member and engageable with the distal linkage to operatively couple the flexible member to the distal linkage. Element11: wherein the distal adapter defines one or more or apertures co-axially alignable with the one or more conduits such that the one or more central actuation members also extend through the one or more apertures. Element12: further comprising a proximal adapter coupled to the second end of the flexible member and slidingly engageable with the proximal linkage. Element13: wherein the flexible member comprises a material selected from the group consisting of polytetrafluoroethylene, silicone, nylon, polyurethane, and any combination thereof. Element14: further comprising one or more drive cables extending from the drive housing and extending through a corresponding one or more apertures defined by the articulable wrist to cause articulation of the articulable wrist.

Element15: wherein articulating the wrist comprises actuating one or more drive cables extending from the drive housing, wherein the one or more drive cables extend through a corresponding one or more apertures defined by the wrist. Element16: further comprising operatively coupling the first end of the flexible member to the distal linkage with a distal adapter fixed to the first end of the flexible member. Element17: further comprising slidingly engaging to the second end of the flexible member against the proximal linkage with a proximal adapter coupled to the second end of the flexible member.