Wrist architecture

Abstract

To provide surgical devices having wrists that can perform yaw and pitch rotations at relatively large angles.SOLUTION: A surgical device includes an elongated shaft, an end effector, and a wrist assembly. The wrist assembly includes a first outer link, a first inner link, and a second outer link. The first outer link is connected to the shaft and includes first gear teeth. The first inner link is pivotally coupled with the first outer link. The second outer link is pivotally coupled with the first inner link. The second outer link includes second gear teeth that engage with the first gear teeth and control orientation of the first inner link relative to the first outer link and the first outer link throughout a range of orientations of the wrist assembly.SELECTED DRAWING: Figure 5B

Description

[Technical Field]

[0001] (Cross-reference to related application data) This application claims the benefit of U.S. Provisional Application No. 62 / 385,621, filed September 9, 2016, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes. [Background technology]

[0002] Minimally invasive surgical techniques aim to reduce the amount of extraneous tissue damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and adverse side effects. As a result, the average length of hospital stays for standard surgeries can be significantly reduced using minimally invasive surgical techniques. Patient recovery time, patient discomfort, surgical side effects, and time away from work can also be reduced with minimally invasive surgery.

[0003] A common form of minimally invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally invasive examination and / or surgery within the abdominal cavity. Reloadable stapling devices can be used in conjunction with these procedures. Telesurgically controlled stapling devices can include a servo-controlled wrist joint that yaws and pitches at relatively extreme angles (e.g., up to and beyond 90 degrees). Such joints can impose significant strain on actuating components that must translate through the wrist at such angles. Thus, current actuating devices are often limited by the ability of the actuating components to function at extreme angles. Summary of the Invention

[0004] The embodiments disclosed herein relate to a surgical device having a wrist capable of yaw and pitch rotation through relatively large angles. Such a wrist can have a yaw axis spatially separated from a pitch axis, both of which are perpendicular to each other and to a longitudinal axis defining the extension of the arm or shaft of the remotely controlled surgical device. In some cases, the yaw and pitch angles can be up to 45, 60, or 90 degrees.

[0005] Such pitch and yaw angles require a highly flexible actuation mechanism for opening and closing the jaws of the surgical device and, optionally, for actuating other instruments, such as a cutting and / or stapling device. In some embodiments, the actuation mechanism may include a pushing component. The pushing component can be adapted to be highly compressible under extreme angles while still being highly flexible. However, the pushing component may not be well suited for tension. Therefore, a separate tension component can be used to apply tension for proximal movement and actuation of the surgical device. Similarly, the tension component may not be well suited for compression. However, a combination of pushing and tension components into one integrated device can be effectively used for both compressive and tension force application (i.e., pushing and pulling) to actuate components of the end effector of the surgical device.

[0006] The pushing component and the tensioning component can be integrated along a common axis, with the pushing component arranged concentrically around the tensioning component. In some embodiments, the pushing component comprises a coil spring and the tensioning component comprises a braided cable. Alternatively, the tensioning component can be arranged concentrically around the pushing component.

[0007] To enable a high degree of wrist flexibility, the wrist assembly can be composed of outer links that define the yaw and pitch geometry for the wrist assembly. The outer links can accommodate flexible portions of the actuation mechanism. However, compression of the actuation mechanism within the wrist can cause buckling and reduce the efficiency of force transmission. To help mitigate such problems, inner links can be provided that connect the outer links to each other. The inner links can define a path that constrains and limits lateral movement of the actuation mechanism, thereby mitigating buckling.

[0008] Thus, in one aspect, a device includes an elongate shaft, an end effector, and a wrist assembly. The elongate shaft extends along a first axis. The end effector includes an upper jaw portion and a lower jaw portion. The wrist assembly movably connects the end effector to the elongate shaft. The wrist assembly includes a first outer link, a first inner link, and a second outer link. The first outer link is connected to the elongate shaft and is movably coupled to the second outer link by the first inner link. The first outer link, the first inner link, and the second outer link define a proximal joint. An inner surface of the first outer link and an inner surface of the second outer link define a lumen in which the first inner link is disposed. The inner surface of the first outer link defines at least a first recess, and the inner surface of the second outer link defines at least a second recess. The radial surface of the first inner link includes at least a first protrusion and a second protrusion, the first protrusion of the first inner link engages with the first recess, and the second protrusion of the first inner link engages with the second recess.

[0009] In some embodiments of the device, the wrist assembly is operable to reorient the end effector relative to the elongate shaft about each of two axes that are perpendicular to the first axis. For example, in some embodiments of the device, the proximal joint extends along a second axis that is perpendicular to the first axis.

[0010] In some embodiments of the device, the wrist assembly is operable to reorient the end effector relative to the elongate shaft about each of two axes perpendicular to the first axis. For example, the wrist assembly can further include a second inboard link and a third outboard link. The third outboard link is connected to the end effector and movably coupled to the second outboard link by the second inboard link. The third outboard link, the second inboard link, and the second outboard link define a distal joint. The wrist assembly can be configured to yaw and pitch rotate at the proximal and distal joints, respectively. In some embodiments of the device, the first inboard link and the second inboard link each include a first and second clevis-projecting journal.

[0011] In some embodiments of the device, the wrist assembly has an internal passageway through which the actuation component extends. For example, some embodiments of the device include an elongated drive member drivingly coupled to the end effector and extending through an internal passageway defined by the first inner link. In some embodiments of the device, the elongated drive member is operable to apply a distally directed force to the end effector. In some embodiments, the internal passageway is closely formed around the elongated drive member to prevent buckling of the elongated drive member during application of a distally directed force to the end effector. In some embodiments, the wrist assembly includes an inner sheath within the internal passageway through which the elongated drive member extends.

[0012] In some embodiments of the device, the first outboard link and the second outboard link interface to control the relative orientation between the first outboard link, the first inboard link, and the second outboard link during articulation of the wrist assembly. For example, in some embodiments, the first outboard link and the second outboard link include intermeshing gear teeth that control the relative orientation between the first outboard link, the first inboard link, and the second outboard link through a range of orientation between the second outboard link and the first outboard link. In some embodiments, the first inboard link is passively constrained by the first outboard link and the second outboard link.

[0013] In another aspect, an apparatus includes an elongated arm, an end effector, an elongated drive member, and a wrist assembly. The elongated arm extends along a first axis. The end effector includes an upper jaw portion and a lower jaw portion. The elongated drive member extends from the elongated arm and is drivably coupled to the end effector for actuation of the end effector. The wrist assembly movably connects the elongated arm to the end effector. The wrist assembly includes a plurality of outboard links and a plurality of inboard links. The wrist assembly is operable to yaw and pitch the end effector relative to the elongated arm. The inboard links define an inner passage between the elongated arm and the end effector through which the elongated drive member extends.

[0014] In some embodiments of the device, the wrist assembly is operable to reorient the end effector relative to the elongate shaft about an axis that is perpendicular to the first axis. For example, in some embodiments of the device, the wrist assembly includes a proximal joint that extends along a second axis that is perpendicular to the first axis.

[0015] In some embodiments of the device, the wrist assembly is operable to reorient the end effector relative to the elongate shaft about each of two axes perpendicular to the first axis. For example, the wrist assembly can further include a distal joint extending along a third axis perpendicular to the first and second axes. In some embodiments, the wrist assembly is configured to yaw rotate at the proximal joint and pitch rotate at the distal joint. In some embodiments, each of the inboard links includes first and second protruding journals.

[0016] In some embodiments of the device, the wrist assembly has an internal passageway through which the actuation component extends. For example, in some embodiments of the device, the internal passageway is tightly formed around the elongated drive member to prevent the elongated drive member from buckling under compression. In some embodiments, the wrist assembly includes an inner sheath within the internal passageway and through which the elongated drive member extends.

[0017] In some embodiments of the device, the outer links abut to control the relative orientation between the outer links and the inner links. For example, in some embodiments, the outer links include intermeshing gear teeth that control the relative orientation between the outer links and the inner links through a range of orientations between the outer links. In some embodiments, the inner links are passively constrained by the outer links.

[0018] In some embodiments, the wrist assembly is actuated via a tension member. For example, in some embodiments, the device includes a cable portion that extends through a portion of the outer link and is articulated to articulate the wrist assembly.

[0019] In another aspect, a surgical device includes an elongate shaft, an end effector, and a wrist assembly. The elongate shaft extends along a first axis. The end effector includes an upper jaw portion and a lower jaw portion. The wrist assembly movably connects the end effector to the elongate shaft. The wrist assembly includes a first outboard link, a first inboard link, and a second outboard link. The first outboard link is connected to the elongate shaft and includes first gear teeth. The first inboard link is pivotally coupled to the first outboard link to rotate relative to the first outboard link about a second axis oriented perpendicular to the first axis. The second outboard link is pivotally coupled to the first inboard link to rotate relative to the first inboard link about a third axis parallel to and offset from the second axis. The second outer link includes second gear teeth that mesh with the first gear teeth and control the orientation of the first outer link and the first inner link relative to the first outer link throughout a range of orientation of the second outer link relative to the first outer link.

[0020] The first inboard link can be pivotally coupled to the first and second outboard links using any suitable pivot connection. For example, in some embodiments of the surgical device, the first inboard link includes a first pair of protruding journals aligned with the second axis and a second pair of protruding journals aligned with the third axis, the first outboard link has a first pair of outboard link journal bearings that abut the first pair of protruding journals, and the second outboard link has a second pair of outboard link journal bearings that abut the second pair of protruding journals.

[0021] The first inboard link, the first outboard link, or the second outboard link can have a multi-piece structure to facilitate assembly of the wrist assembly. For example, in some embodiments of the surgical device, the first inboard link has a multi-piece structure including a first inboard link first portion and a first inboard link second portion. In some embodiments of the surgical device, the first inboard link first portion and the first inboard link second portion are configured to interface with one of the first outboard link and the second outboard link via rotation of the first inboard link first portion and the first inboard link second portion, respectively, relative to one of the first outboard link and the second outboard link. In some embodiments of the surgical device, the other of the first outboard link and the second outboard link has a multi-piece structure configured to accommodate assembly to the first inboard link after the first inboard link is assembled with one of the first outboard link and the second outboard link.

[0022] In some embodiments of the surgical device, the wrist assembly defines an opening through which the actuation assembly extends. For example, in some embodiments, the first inner link defines the opening and the surgical device includes an elongated drive member extending through the opening and drivingly coupled to the end effector for actuating a mechanism of the end effector.

[0023] In some embodiments of the surgical device, the wrist assembly is cable driven and configured to react to both proximal and distal loads applied to the end effector without relying on cable tension to react to the distal loads to avoid separation of the wrist assembly components. For example, in some embodiments, the surgical device includes cable segments drivingly coupled to the wrist assembly and coupled to articulate the wrist assembly, and the first inner link is configured to react to both tensile and compressive loads applied to the end effector by the drive member and returned to the first outer link so as to keep the second outer link in contact with the first outer link even when none of the cable segments is under tension.

[0024] In some embodiments of the surgical device, the wrist assembly is operable to reorient the end effector relative to the elongate shaft about two axes perpendicular to the first axis. For example, the wrist assembly can further include a second inboard link and a third outboard link. The second inboard link can be pivotally coupled to the second outboard link to rotate relative to the second outboard link about a fourth axis oriented perpendicular to the first and third axes. The third outboard link can be pivotally coupled to the second inboard link to rotate relative to the second inboard link about a fifth axis parallel to and offset from the fourth axis. The third outboard link can include gear teeth that interface with the gear teeth of the second outboard link and control the orientation of the third outboard link and the second inboard link relative to the second outboard link over a range of orientations of the third outboard link relative to the second outboard link.

[0025] The second inboard link can be pivotally coupled to the second and third outboard links using any suitable pivot connection. For example, in some embodiments of the surgical device, the second inboard link includes a first pair of protruding journals aligned with the fourth axis and a second pair of protruding journals aligned with the fifth axis, the second outboard link includes a second pair of outboard link journal bearings that abut the first pair of protruding journals of the second inboard link, and the third outboard link includes a third pair of outboard link journal bearings that abut the second pair of protruding journals of the second inboard link.

[0026] The second inboard link, the second outboard link, or the third outboard link can have a multi-piece structure to facilitate assembly of the wrist assembly. For example, in some embodiments of the surgical device, the second inboard link has a multi-piece structure having a second inboard link first portion and a second inboard link second portion. In some embodiments, the second inboard link first portion and the second inboard link second portion are configured to interface with one of the second outboard link and the third outboard link via rotation of the second inboard link first portion and the second inboard link second portion, respectively, relative to one of the second outboard link and the third outboard link. In some embodiments, the other of the second outboard link and the third outboard link has a multi-piece structure configured to accommodate assembly to the second inboard link after the second inboard link has been assembled with one of the second outboard link and the third outboard link.

[0027] In some embodiments of the surgical device, the wrist assembly defines an opening through which the actuation assembly extends. For example, in some embodiments, the second inner link defines a second inner link opening. The surgical device can include an elongated drive member extending through the second inner link opening and drivingly coupled to the end effector for actuating a mechanism of the end effector.

[0028] In some embodiments of the surgical device, the wrist assembly is cable driven and configured to resist both proximal and distal loads applied to the end effector without relying on cable tension to resist the distal loads to avoid separation of the wrist assembly components. For example, the surgical device may include cable segments drivingly coupled to the wrist assembly and connected to articulate the wrist assembly. The first and second inboard links can be configured to resist both tensile and compressive loads applied to the end effector by the drive member and returned to the first outboard link to keep the third outboard link in contact with the second outboard link and the second outboard link in contact with the first outboard link even when none of the cable segments are under tension. [Brief explanation of the drawings]

[0029] [Figure 1A] 1 shows a diagram of a surgical tool according to many embodiments. [Figure 1B] 1 shows a diagram of a surgical tool according to many embodiments. [Figure 1C] 1 shows a diagram of a surgical tool according to many embodiments. [Figure 2A] 1 shows a perspective view of a surgical tool according to many embodiments. [Figure 2B] 1 illustrates a side view of a surgical tool according to many embodiments. [Figure 2C] 1 illustrates a bottom view of a surgical tool according to many embodiments. [Figure 3A] 1 illustrates a cross-sectional view of a surgical tool according to many embodiments. [Figure 3B] 1 illustrates a cross-sectional view of a surgical tool according to many embodiments. [Figure 4A] 1 shows a perspective view of an actuation mechanism according to many embodiments. [Figure 4B] 1 illustrates a cross-sectional view of an actuation mechanism according to many embodiments. [Figure 4C] 1 illustrates a perspective view of a pressing member according to many embodiments. [Figure 4D]1 illustrates a perspective view of a pressing member according to many embodiments. [Figure 4E] 1 illustrates a cross-sectional view of an actuation mechanism according to many embodiments. [Figure 5A] FIG. 1 illustrates a perspective view of a wrist assembly according to many embodiments. [Figure 5B] FIG. 1 illustrates a cross-sectional view of a wrist assembly according to many embodiments. [Figure 5C] FIG. 1 illustrates a perspective view of an outer link assembly according to many embodiments. [Figure 6A] 1 illustrates a method of assembling a wrist assembly according to many embodiments. [Figure 6B] 1 illustrates a method of assembling a wrist assembly according to many embodiments. [Figure 6C] 1 illustrates a method of assembling a wrist assembly according to many embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0030] 1A-1C illustrate a surgical tool 10 including a proximal chassis 12, an instrument shaft 14, and a distal end effector 16 having an upper jaw 18 that can be articulated to grasp patient tissue. The proximal chassis 12 includes an input coupler 22 that can interface with and be driven by a corresponding output coupler of a telesurgical system, such as the system disclosed in U.S. Patent Application Publication No. 2014 / 0183244, incorporated herein by reference. The input coupler 22 is drivingly coupled to one or more input members disposed within the instrument shaft 14. The input members are drivingly coupled to the end effector 16. As shown in FIGS. 1B and 1C, the input coupler 22 of the proximal chassis 12 can be configured to mate with various types of motor packs 13, such as a stapler-specific motor pack disclosed in U.S. Patent No. 8,912,746 or a general-purpose motor pack disclosed in U.S. Patent No. 8,529,582, both of which are incorporated herein by reference.

[0031] 2A-2C show perspective, side, and top views of the distal end of surgical tool 10, including end effector 16. End effector 16 is movably connected to instrument shaft 14 by wrist assembly 24. Wrist assembly 24 has at least two degrees of freedom and provides attachment of end effector 16 to elongated instrument shaft 14 for articulation of end effector 16 about two axes orthogonal to instrument shaft 14. Wrist assembly 24 is configured to yaw rotate about axis 2-2, which is perpendicular to axis 1 along which instrument shaft 14 extends. Wrist assembly 24 is also configured to pitch rotate about axis 3, which is perpendicular to axes 1 and 2. As shown, yaw axis 2 is proximal (farther from end effector 16) than pitch axis 3, although this is not a requirement, and in some embodiments, yaw axis 2 is distal to pitch axis 3.

[0032] 3A and 3B are cross-sectional views showing details of the end effector 16, including the upper jaw portion 18 and the lower jaw portion 26. The lower jaw portion 26 can be configured to receive and support a removable or non-removable staple cartridge. The upper jaw portion 18 is pivotally coupled to the lower jaw portion 26 for articulation relative to the lower jaw portion 26 to clamp tissue. A beam member 28 is actuated from a proximal state shown in FIG. 3A to a distal state shown in FIG. 3B to articulate the upper jaw portion. Movement of the beam member 28 can act to forcefully secure the upper jaw portion 18 onto the tissue relative to the lower jaw portion 26. Optionally, the beam member 28 can also cut tissue and allow staples to be deployed from the cartridge into the cut tissue.

[0033] The beam member 28 includes an upper beam portion 30 configured to slide within a rail mechanism 32 of the upper jaw 18. The rail mechanism 32 includes a ramp 34 for the upper beam portion 30 to engage from a proximal-most garage region 36. The open position shown in FIG. 3A can be maintained by a resilient device, such as a spring, or can be opened and closed by a secondary mechanism (not shown). Partial closure of the upper jaw 18 can be effected by distal movement of the upper beam portion 30 up the ramp 34. Full closure of the upper jaw 18 is achieved when the upper beam portion 30 is moved distally on the rail mechanism 32 over the ramp 34. Proximal movement of the upper beam portion 30 away from the ramp 34 relieves the closure force applied by the beam member. The resilient device or secondary mechanism can then open the closed or partially closed upper jaw 18. Thus, back and forth movement of the upper beam portion 30 along the ramp 34 can toggle the end effector 16 between open and closed.

[0034] Beam member 28 also includes a lower beam portion 38 configured to slide within rail mechanism 32 of lower jaw 18. Lower beam portion 38 can actuate a sled (such as disclosed in U.S. Patent Application Publication No. 2014 / 0183244) configured to eject staples from lower jaw 26 during distal movement of beam member 28. Alternatively, lower beam portion 30 can be integral with such a sled.

[0035] 4A shows a perspective view of beam member 28. Here, upper beam portion 30 includes an integral cutting member 40 configured to cut tissue. However, in other embodiments, the tissue cutting device can be separate from beam member 28 or can be mounted within beam member 28 in a different manner. Upper beam portion 30 includes an upper flange 42 extending laterally from integral cutting member 40. Slider portion 42 is configured to directly couple with rail mechanism 32 and ramp 34. In a similar manner, lower flange 44 is provided to slide on the rail mechanism of lower jaw 26. An elongated drive member 46 is attached to beam member 28 to provide distal and proximal movement for drive member 46.

[0036] FIG. 4B shows a cross-sectional view of the beam member 28 and the drive member 46. The drive member 46 includes a push member 48 and a tension member 50. The push member 48 is configured as a close-coiled spring and is adapted to transmit the axial force applied by the drive rod 52. The push member 48 can be externally constrained by a sheath 54, which can be constructed from a lubricious polymer material such as PTFE. The coiled design of the push member 48 allows a compressive force to be efficiently transmitted to the beam member 28 to push the beam member 28 distally. The push member 48 can be constructed from coiled wire in a conventional manner or can be helically cut from a tube. In some cases, the compressive element (e.g., coil) of the push member separates under tension; in such cases, the push member may only be effective in transmitting compressive forces.

[0037] The tension member 50 may be comprised of a braided cable or other flexible rod and may be held within the beam member 28 by a crimp portion 56. In some cases, the tension member may be relatively ineffective at transmitting pushing forces because it may be prone to collapsing or buckling itself; therefore, in such cases, the tension member may be effective only at transmitting tensile forces. The tension member 50 is also adapted to translate axial forces applied by the drive rod 52. The drive rod 52 is disposed within the instrument shaft 14 and is drivingly coupled to one or more of the input couplers 22 shown in FIG. 1 . The tension member 50 allows the tensile force to be effectively transferred from the drive rod 52 to the beam member 28 while pulling the beam member 28 in a proximal direction. The push member 48 and the tension member 50 operate in a complementary manner to provide distal and proximal movement to the beam member 28 by separating the tensile force on the tension member 50 and the compressive force on the push member 48. This allows for a very flexible and compact design of the drive member 46, a characteristic that allows the drive member 46 to translate within the wrist 24, which can be positioned at severe yaw and pitch angles during operation.

[0038] The pressure member is not limited to a tightly wound spring design, as shown in FIG. 4B. For example, a flexible pressure member 58, as shown in FIG. 4C, can be formed from a solid tube by cutting a pattern into the solid tube to increase bending flexibility at the wrist without substantially reducing compression stiffness. Here, the pressure member 58 is formed by laser cutting a pattern into a metal tube. The pattern here allows for flexibility where gaps are formed in the tube and axial stiffness where material is left in place. Another example of a flexible pressure member is shown in FIG. 4D, which shows a pressure member 60 with multiple circumferential slits arranged in a spiral pattern.

[0039] FIG. 4E shows an alternative configuration of drive member 60. The configuration here is opposite to that depicted in FIG. 4B, in which push member 48 concentrically surrounds pull member 50. Here, drive member 60 includes pull member 62 configured as a braided sheath enclosing push member 64. Push member 64 is configured as a plurality of spherical members (e.g., ball bearings) joined by flexible rod 66. Both push member 64 and pull member 62 are actuated by drive rod 52, which is drivingly coupled to one or more of input couplers 22 shown in FIG. 1.

[0040] 5A and 5B show perspective and cross-sectional views of the wrist assembly 24. The wrist assembly 24 includes a proximal outboard link 100, an intermediate outboard link 102, and a distal outboard link 104. These three links determine the kinematic pitch and yaw motion of the wrist assembly 24. As shown, the interface between the proximal outboard link 100 and the intermediate outboard link 102 determines the yaw motion of the wrist assembly 24. The interface between the outer distal link 104 and the intermediate outboard link 102 determines the pitch motion of the wrist assembly 24. However, in alternative wrist configurations, this relationship can be reversed (e.g., by rotating the end effector 16 90 degrees relative to the wrist assembly 24) so that the wrist assembly 24 pitches between the proximal outboard link 100 and the intermediate outboard link 102 and yaws between the distal outboard link 100 and the intermediate outboard link 102.

[0041] The cable portions 106 are drivingly coupled to the wrist assembly 24 and actuated to impart movement to the wrist assembly 24. In some embodiments, the cable portions 106 can be individually secured to a portion of the distal outer link 104. In a functionally equivalent alternative embodiment, as shown in FIG. 5A , the cable portions 106 are looped around a portion of the distal outer link 104 as shown. Looping the cable portions 106 around the distal outer link 104 can be used to secure the cable portions 106 to the distal outer link 104. The cable portions 106 can be coupled to articulate the wrist assembly 24. Differential movement of the cable portions 106 can be used to actuate the wrist assembly 24 to pitch and yaw at various angles. The cable portions 106 can be drivingly coupled to one or more of the input couplers 22 shown in FIG. 1 . The wrist assembly also includes a proximal inner link 108 and a distal inner link 110, which are discussed in detail below.

[0042] Attention is now directed to FIG. 5C, which illustrates an exemplary embodiment of a joint 112 representing the interface between the outer links shown in FIGS. 5A and 5B. The joint 112 includes a first link 114 and a second link 116. The first link 114 may include gear teeth 118, 120 and a bearing (support) projection 122. The second link 116 includes gear teeth 124, 126, 128 and a bearing projection 130. According to an exemplary embodiment, the projections 122, 130 of the first and second links 114, 116 may include passages that allow the cable portion 106 to pass through. Because the bearing projections 122, 130 are positioned outboard relative to the central openings 134, 136, the cable portion 106 extending through the passage adjacent the bearing projections 122, 130 is also positioned outboard. This allows for routing of other features through the central openings 134, 136. The actuation kinematics between the links 114, 116 are determined by the shape of the gear teeth 118, 120, 124, 126, 128 that engage and disengage during movement. The bearing protrusions 122, 130 included curved surfaces that could engage at appropriate points throughout the angular movement to help reduce compressive strain on the gear teeth 118, 120, 124, 126, 128.

[0043] The increased range of motion provided by joint 112 allows a wrist including joint 112 to provide a desired amount of motion, such as ±90 degrees, in the pitch or yaw direction in a more efficient manner with fewer parts. In conventional wrist structures where each joint is limited to a maximum roll angle of approximately 45 degrees, several such joints in series are required to achieve a relatively large roll angle for the entire wrist mechanism. In the illustrated embodiment, a single joint 112 can provide an angular deflection of up to 90 degrees. As a result, the manufacturing cost and complexity of a wrist including one or more joints 112 is reduced while still achieving the desired angular deflection. Additionally, gear teeth 118, 120, 124, 126, 128 included on links 114, 116 of joint 112 can provide improved timing to help accurately position links 114, 116, including, for example, returning links 114, 116 to a neutral position (e.g., zero-angle roll alignment), and to increase the smoothness of movement between links 114, 116, such as when links 114, 116 are reoriented relative to one another. According to an exemplary embodiment, a wrist may include multiple joints 112 to achieve a higher range of motion (up to a roll limit angle), such as a wrist with a range of motion of up to ±180 degrees in pitch or yaw. Further details of joint 112 and other joints usable with the embodiments disclosed herein are disclosed in International Publication No. WO 2015 / 127250, which is incorporated herein by reference.

[0044] As shown in FIG. 5B, the proximal inner link 108 and the distal inner link 110 are spatially separated along axis 1 and offset 90 degrees from each other. Therefore, the proximal inner link 108 is only partially shown. The radial surfaces of the proximal and distal inner links 108, 110 include protrusions (e.g., configured as protruding journals 140). The protrusions interface with recesses (e.g., configured as journal bearings 142) on the inner surfaces of the outer links. In some embodiments, the protruding journals 140 and journal bearings 142 set the distance between the outer links but are otherwise passive and do not change the joint kinematics of the outer links, which are determined by the geometry of the gear teeth 118, 120, 124. Each side of the proximal and distal inner links 108, 110 includes a pair of commonly aligned protruding journals 120 that interface with journal bearings 142 for a total of four protruding journals 140 per inner link 108, 110. Each pair of protruding journals 140 is separated to provide an internal passageway 144 for the drive member 46 .

[0045] An additional inner sheath 146 can be used to further support the drive member 46. The drive member 46 slides axially within the inner sheath 146. The inner sheath 146 is fixed to the distal end portion of the wrist assembly 24 and is flexible to bend with movement of the wrist assembly 24, but does not move axially. The inner sheath 146 and inner passage 144 provided by the inner links 108, 110 act to guide and constrain the drive member 46 during axial movement. The inner sheath 146 and inner passage 144 prevent the drive member from buckling under compressive loads (i.e., distal movement during cutting and stapling). Conventional wrist designs, such as those disclosed in the aforementioned International Publication No. WO 2015 / 127250, rely on tensioned cables to maintain the outer links in position. Here, as the drive member 46 moves distally, the resulting compressive forces can be opposed via the inner links 108, 110, thereby preventing potential stretching and resulting loss of tension in the cable 106. As the drive member 46 moves distally, the protruding journals 140 of the inner links 108, 110 advantageously maintain the outer links in place, thus maintaining the structure of the wrist assembly 24.

[0046] Each inboard link 108, 110 can have a two-piece construction, as shown in FIGS. 6A-6C, which also illustrate a technique for assembling the inboard link to the outboard link. In FIG. 6A, the first link portion 108a and the second link portion 108b of the proximal inboard link 108 are positioned to place the protruding journal 140 within the journal bearing 142 of the intermediate outboard link 102. The first link portion 108a and the second link portion 108b are inserted at an angle so that the gear teeth 148 on each portion intermesh, aligning the portions into the configuration shown in FIG. 6B. The gear teeth 148 are assembly aids that eliminate the need for pins or other fasteners and are not used for movement beyond assembly. However, in some embodiments, fasteners can be used in place of the gear teeth. After the link portions 108a, 108b are assembled into the complete inboard proximal link 108, the proximal outboard link 100 is assembled over the remaining exposed protruding journal 140, resulting in the configuration shown in FIG. 6C. In one embodiment, as shown in FIG. 6C, the proximal outer link 100 is also a two-piece construction.

[0047] Other variations are within the spirit of the invention. Various aspects, embodiments, implementations, or features of the described embodiments may be used separately or in any combination. Various aspects of the described embodiments relating to the operation of the telesurgery tool may be implemented by software, hardware, or a combination of hardware and software. Accordingly, while the invention is susceptible to various modifications and alternative constructions, specific illustrative embodiments thereof have been shown in the drawings and described above in detail. It should be understood, however, that there is no intention to limit the invention to the particular forms disclosed, but rather, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention, as defined by the appended claims.

[0048] Use of the terms "a," "an," "the," and similar referents in the context of describing the present invention (particularly in the context of the claims below) should be construed to encompass both the singular and the plural unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise noted. The term "connected" should be construed as partially or wholly contained within, attached to, or joined together, even if there is intervening material. Recitation of ranges of values herein is merely intended to serve as a shorthand method of individually referring to each separate value falling within the range, unless otherwise specified herein, and each separate value is incorporated herein as if it were individually set forth herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. Any and all examples provided herein, or the use of exemplary language (e.g., "such as"), are intended merely to better illuminate embodiments of the invention and do not pose a limitation on the scope of the invention unless specifically recited in the claims. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0049] Preferred embodiments of the present invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of these preferred embodiments will become apparent to those skilled in the art upon reading the foregoing description. The inventors expect those skilled in the art to employ such variations as they see fit, and the inventors intend to practice the invention otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or clearly contradicted by context.

Claims

1. An elongated shaft extending along a shaft axis; an end effector having an upper jaw and a lower jaw; and a wrist assembly movably connecting the end effector to the elongate shaft, the wrist assembly comprising: having a first outer link, a first inner link, and a second outer link; the first outer link is connected to the elongate shaft and movably coupled to the second outer link by the first inner link; the first outboard link, the first inboard link, and the second outboard link define a proximal joint; an inner surface of the first outer link and an inner surface of the second outer link define a lumen in which the first inner link is disposed; the inner surface of the first outboard link defines a first pair of recesses, the inner surface of the second outboard link defines a second pair of recesses, the first pair of recesses aligned with a first axis about which the first inner link is constrained to rotate relative to the first outer link, the second pair of recesses aligned with a second axis about which the second outer link is constrained to rotate relative to the first inner link, the second axis being offset from and parallel to the first axis; a radial surface of the first inner link including a first pair of protrusions and a second pair of protrusions; each protrusion of the first pair of protrusions engages a respective one of the recesses of the first pair of recesses; each protrusion of the second pair of protrusions engages a respective one of the recesses of the second pair of recesses; the wrist assembly; Device.

2. Each of the first axis and the second axis is perpendicular to the shaft axis.

10. The apparatus of claim 1.

3. The wrist assembly further has a second inner link and a third outer link, the third outer link connected to the end effector and movably coupled to the second outer link by the second inner link; the third outer link, the second inner link, and the second outer link defining a distal joint.

3. The device according to claim 1 or 2.

4. The first pair of recesses includes a first pair of journal bearing recesses, and the second pair of recesses includes a second pair of journal bearing recesses; the first pair of protrusions includes a first pair of protruding journals, and the second pair of protrusions includes a second pair of protruding journals; 4. An apparatus according to any one of claims 1 to 3.

5. The first inner link defines an internal passageway extending longitudinally through the wrist assembly from a first end of the first inner link to a second end of the first inner link opposite the first end of the first inner link; 5. An apparatus according to any one of claims 1 to 4.

6. The first inner link has a two-piece structure including a first inner link piece and a second inner link piece separated along a direction from the first end of the first inner link to the second end of the first inner link.

6. The apparatus of claim 5.

7. The shaft defines a shaft lumen extending longitudinally of the shaft; and the apparatus further includes an elongated drive member extending proximally from the end effector through the internal passage of the first inner link and through the shaft lumen.

6. The apparatus of claim 5.

8. The first outer link has a first plurality of gear teeth; the second outer link having a second plurality of gear teeth configured to sequentially engage the first plurality of gear teeth through a plurality of different relative orientations of the first outer link and the second outer link; the sequential engagement of the first and second plurality of gear teeth controls the relative orientation between the first and second outer links.

8. An apparatus according to any one of claims 1 to 7.

9. The system further includes one or more cables extending through the first outer link and the second outer link, the first outer link and the second outer link being configured to change angular orientation relative to one another within a predetermined range of motion in response to forces transmitted by the one or more cables.

9. An apparatus according to any one of claims 1 to 8.

10. The first outer link has a first bearing surface; the second outer link having a second bearing surface; the first bearing surface and the second bearing surface are configured to engage one another within the predetermined range of motion; 10. The apparatus of claim 9.

11. A proximal chassis including a drive mechanism; an elongate arm coupled to the proximal chassis, the elongate arm extending along a first axis and defining a shaft lumen; an end effector having an upper jaw and a lower jaw; an elongated drive member extending through the shaft lumen and drivingly coupling the drive mechanism to the end effector for actuation of the end effector; and a wrist including outboard links and inboard links, the end effector being supported by the elongated arm via the outboard links and the inboard links, each of the inboard links pivotally coupled to each of two of the outboard links, the wrist operable to yaw and pitch the end effector relative to the elongated arm, the inboard links defining an internal passageway between the elongated arm and the end effector through which the elongated drive member extends; Device.

12. Each of the outer links has gear teeth, and the gear teeth of each of the outer links abut the gear teeth of another of the outer links.

12. The apparatus of claim 11.

13. The inner surface of each of the outer links defines a lumen in which a respective inner link is disposed.

12. The apparatus of claim 11.

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