Relief features for instrument shafts, and related devices, systems, and methods

Abstract

An instrument including a tubular shaft and an end effector coupled to a distal end portion of the shaft includes relief features in a wall of the shaft and extending around a circumference of the shaft along at least a portion of a length of the shaft, the relief features having a kerf pattern defining complementary interlocking elements on opposite sides of the relief features. The complementary interlocking elements can move relative to one another in response to bending of the shaft and can comprise surface portions engaging each other over a range of bend angles of a bent region of the shaft from neutral through a predetermined bend angle at both a tension side and a compression side of the bent region of the shaft.

Description

RELIEF FEATURES FOR INSTRUMENT SHAFTS, AND RELATED DEVICES, SYSTEMS, AND METHODSCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application 63 / 678,790, filed August 2, 2024, the entirety of which is incorporated by reference herein.TECHNICAL FIELD

[0002] Aspects of the present disclosure relate to instrument shafts with relief features that provide flexibility of the shaft so as to permit bending of the shaft. More specifically, aspects relate to kerf patterns that provide relief features enabling bending of the shaft while providing desirable axial stiffness in a bent configuration and hindering rotational backlash under torque load. Related devices, systems, and methods also are disclosed. INTRODUCTION

[0003] Instruments, such as medical or industrial instruments, which are configured for remote actuation, can have a variety of configurations to perform various types of procedures. Such instruments can include a shaft, an end effector at a distal end portion of a shaft for positioning at a site at which a procedure will take place, and a transmission mechanism positioned proximally of the end effector along the shaft, such as at a proximal end portion of the shaft. Actuation elements can extend along the shaft and be coupled between drive devices of the transmission mechanism and portions along the shaft and / or end effector. In this way, inputs that drive the drive devices can be transmitted through the actuation elements to control motion of portions of the shaft, articulable segments along the shaft, and / or the end effector.

[0004] The inputs to drive devices of the transmission mechanisms can be provided manually and / or via a teleoperated computer-assisted manipulator system. When configured to receive drive inputs via a computer-assisted manipulator system, the transmission mechanism is configured to mount (removably or permanently) the instrument to the manipulator system. Transmission mechanisms of these instruments can include numerous types of drive devices that receive mechanical and / or electrical input, e.g., from the manipulator system or manually via a user, and generate movement and actuation of the instrument, such as operation of the end effector,articulation of one or more articulable segments of the shaft proximal of the end effector, shaft roll, and other operations or movements (including, e.g., providing various fluxes to be delivered by the instrument, such as electrical energy, irrigation, suction, light, and other similar flux). Other instruments in medical, industrial, or other use applications can include shafts and associated components with similar construction and function.

[0005] For various reasons, it may be desirable to provide shafts of such instruments with a degree of flexibility. For example, in a system with multiple instruments like those described above being configured to carry out a procedure at a common remote worksite, the end effectors of the instrument shafts may be in close proximity. Because of the potentially large number of mechanical components and associated transmission mechanisms, the size of the transmission mechanisms constrains how closely together the proximal end portions of the shafts can be positioned. Allowing the instrument shaft some bending flexibility can enable the distal end portions and end effectors to be in relatively close proximity while allowing sufficient clearance for the transmission mechanisms, even if instrument shafts are positioned so as to extend generally parallel to each other. In other applications and system architectures, a degree of flexibility to allow the shaft to bend nominally may be desired for other reasons.

[0006] Shafts made from inherently flexible materials can behave in undesirable ways for certain applications, such as exhibiting higher axial compliance than desirable. This can also lead to rotational backlash. In some cases, shafts with relief features, such as partial or total removal of material through a wall of the shaft, have been utilized to impart flexibility to a shaft made of a generally rigid material (such as metal or hard plastic).

[0007] There exists a need to provide an instrument shaft that exhibits a relatively high compliance in bending while also exhibiting relatively high axial and rotational stiffness. In addition, there exists a need to improve upon shafts that use relief features, such as, for example, kerf patterns winding at least partially around a shaft circumference.SUMMARY

[0008] Exemplary embodiments of the present disclosure may solve one or more of the above-mentioned problems and / or may demonstrate one or more of the above- mentioned desirable features. Other features and / or advantages may become apparent from the description that follows.

[0009] In accordance with at least one aspect of the present disclosure, an instrument including a tubular shaft and an end effector coupled to a distal end portion of the shaft includes relief features in a wall of the shaft and extending around a circumference of the shaft along at least a portion of a length of the shaft, the relief features having a kerf pattern defining complementary interlocking elements on opposite sides of the relief features. The complementary interlocking elements can move relative to one another in response to bending of the shaft and can comprise surface portions engaging each other over a range of bend angles of a bent region of the shaft from neutral through a predetermined bend angle at both a tension side and a compression side of the bent region of the shaft.

[0010] In another aspect, an instrument comprising a tubular shaft having a longitudinal axis and an end effector coupled to a distal end portion of the shaft includes relief features in a wall of the shaft and extending around a circumference of the shaft along at least a portion of a length of the shaft, the relief features having a kerf pattern defining complementary interlocking elements on opposite sides of the relief features. On the condition that the shaft is in a neutral position, the kerf pattern defines a gap between the complementary surfaces on opposite sides of the relief features, the gap varying in width at different locations of the relief features. On the condition that the shaft is bent to an angle within a range of bending angles from neutral through a predetermined bend angle, the complementary surfaces engage one another and prevent lateral movement of the complementary surfaces relative to one another about the longitudinal axis.

[0011] In yet another aspect, the present disclosure contemplates a method including bending a portion of a shaft from a neutral, unbent state of the portion of the shaft to an angle in a range from neutral to a predetermined nominal angle, and in response tobending, engaging complementary surfaces of complementary interlocking elements defined by a kerf pattern of relief features in a wall of the shaft. The method further includes preventing, from the engaging, relative lateral motion of the complementary surfaces on a tension side and a compression side of the portion of the shaft bent from the bending.

[0012] Additional objects, features, and / or advantages will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present disclosure and / or claims. At least some of these objects and advantages may be realized and attained by the elements and combinations particularly pointed out in the appended claims.

[0013] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the claims; rather the claims should be entitled to their full breadth of scope, including equivalents.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present disclosure can be understood from the following detailed description, either alone or together with the accompanying drawings. The drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification. The drawings illustrate one or more exemplary embodiments of the present teachings and, together with the description, explain certain principles and operation. In the drawings,

[0015] FIG. 1 is a partial schematic view of an embodiment of a manipulator arm of a manipulator system of a computer-assisted surgical system with two instruments in a mounted position.

[0016] FIG. 2A is a side view of an instrument according to the present disclosure in an uninstalled position.

[0017] FIG. 2B is a front view of the instrument of FIG. 2A.

[0018] FIG. 2C is a side view of the instrument of FIGS. 2A and 2B in an installed position.

[0019] FIG. 2D is a front view of the instrument in the installed position of FIG. 2C.

[0020] FIG. 3 is a schematic, side view of an instrument according to an embodiment of the present disclosure.

[0021] FIG. 4 is a schematic side view of an instrument shaft having relief features according to the present disclosure.

[0022] FIG. 5 is a partial, enlarged view of the instrument shaft of FIG. 4.

[0023] FIG. 5A shows a detailed portion 5A of FIG. 5.

[0024] FIG. 6A is a partial enlarged side view showing one configuration of a kerf pattern for relief features and corresponding formed interlocking elements of the instrument shaft in an as-cut neutral state of the instrument shaft.

[0025] FIG. 6B is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 6A on a compression side of a shaft in a bent state.

[0026] FIG. 60 is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 6A on a tension side of the shaft in a bent state.

[0027] FIG. 7A is a partial enlarged side view of an instrument shaft showing another kerf pattern for relief features and corresponding formed interlocking elements in a neutral unbent state of the shaft.

[0028] FIG. 7B is a partial enlarged side view of showing the kerf pattern and interlocking elements of FIG. 7A on a compression side of the shaft in a bent state.

[0029] FIG. 7C is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 7A on a tension side of the shaft in a bent state.

[0030] FIG. 8 is a partial enlarged side view of an instrument shaft showing another kerf pattern for relief features and corresponding formed interlocking elements in a neutral, unbent state of the shaft.

[0031] FIG. 8A is a detailed view of portion 8A in FIG. 8.

[0032] FIG. 9A is a partial enlarged side view showing yet another configuration of a kerf pattern for relief features and corresponding formed interlocking elements of the instrument shaft in an as-cut neutral state of the instrument shaft.

[0033] FIG. 9B is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 9A on a compression side of a shaft in a bent state.

[0034] FIG. 9C is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 9A on a tension side of the shaft in a bent state.

[0035] FIG. 10A is a partial enlarged side view showing yet another configuration of a kerf pattern for relief features and corresponding formed interlocking elements of the instrument shaft in an as-cut neutral state of the instrument shaft.

[0036] FIG. 10B is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 10A on a compression side of a shaft in a bent state.

[0037] FIG. 10C is a partial enlarged side view showing the kerf pattern and interlocking elements of FIG. 10A on a tension side of the shaft in a bent state.

[0038] FIGs. 11 A and 11 B schematically illustrate a nominal bend angle of an instrument shaft having a single bend and having multiple bends, respectively.DETAILED DESCRIPTION

[0039] The present disclosure contemplates shafts for instruments that include relief features that impart lateral flexibility (bending) to the shaft while maintaining relatively high axial stiffness and hindering (e.g., reducing or eliminating) rotational backlash to allow controlled roll of the shaft. Such shafts can be made from relatively stiff materials, such as metal alloys, polymers, or other materials to provide the desired stiffness and durability under the specific conditions (such as various applied loads) under which the instrument is used, while the relief features impart flexibility and allow some degree of bending. For example, in one use implementation, such shafts can facilitate coupling the instrument to a manipulator system in a use configuration in which one or more portions of the instrument shaft is bent along a curve to a nominal bend angle as measured between a distal end portion of the instrument relative to a proximal end portion of the instrument mounted to a manipulator. Reference is made to FIGs. 11 A and 11 B respectively schematically illustrating an instrument shaft having a single bend and multiple (e.g. 2 in FIG. 11 B, but any number of bends is contemplated) bends and the nominal bend angle between a distal end portion of the shaft 1105 and the proximal end portion of shaft 1105. Shafts in accordance with the present disclosure are notlimited to the above use however and can be used in any other situation where a degree of shaft flexibility and bending is desired.

[0040] In shafts that utilize relief features for providing lateral bending, the relief features can be provided by removing material circumferentially around at least a portion of the shaft and at least partially through a wall thickness of the shaft, thereby defining adjacent portions of the shaft on either side of a relief feature. Shafts with such relief features can withstand reaction forces resulting from actions such as actuating a moveable component, such as an end effector or wrist joints coupled to the shaft, rotating the shaft in a roll motion, or other movements, with reduced deflection as compared to conventional shafts exhibiting a similar degree of flexibility. The relief features can be provided by making a repeating series (or continuous) cut or other removal of material in a pattern (referred to as a kerf pattern herein) by those having ordinary skill in the art) in a wall of the instrument shaft that extends along at least a portion of the length of the shaft. The removal of material and corresponding relief feature kerf pattern can be formed via various techniques, including but not limited to cutting, such as laser cutting, water-jet cutting, milling, chemical etching, and other such techniques known to those of ordinary skill in the art.

[0041] Kerf patterns for the relief features contemplated by the present disclosure can achieve various design criteria that may provide advantages in shaft kinematics, instrument operation, and manufacturing. By way of example, kerf patterns in accordance with various implementations disclosed herein can facilitate manufacturing by providing patterns that promote efficiency in cutting, including both time and accuracy, while also hindering rotational backlash and providing desirable axial stiffness throughout a range of bending of a shaft from a neutral configuration to a predetermined nominal bend angle. Stated differently, the kerf pattern can minimize rotational backlash in situations where the shaft is bent to an angle that is between the neutral configuration and the predetermined nominal bend angle. In addition, kerf patterns contemplated by the present disclosure maintain a desired range of axial stiffness while also promoting interlocking of complementary features on opposing sides of the kerf pattern to allow engagement and resistance of relative movement of interlocking elements formed bythe kerf pattern on both a tension and compression side of a bent shaft portion, irrespective of whether an external axial load is applied to the shaft or not. Further by providing such axial stiffness, the introduction of errors in transmitting motion from a proximally located transmission mechanism to a moveable component located more distally along the shaft of the instrument can be avoided, which can reduce the complexity of the transmission mechanism and other controls that may otherwise be implemented to address such errors.

[0042] Shafts having the kerf patterns of the relief features in accordance with configurations of the present disclosure can facilitate positioning of associated instruments as desired, such as in a multiple-instrument configuration as discussed above and below in connection with FIG. 1 .

[0043] In the description below, shafts having relief features forming kerf patterns according to various exemplary implementations are disclosed and described in connection with a manipulator system that is configured to mount multiple instruments. However, shafts having the relief features and kerf patterns for the relief features disclosed herein can be used in any application for which flexibility of the shaft for positioning of the shaft is desired, without significantly compromising axial and rotational stiffness of the shaft.

[0044] Referring now to FIG. 1 , a schematic view of a manipulator system 100 including a manipulator arm 103 with two medical instruments 104, 106 in an installed position is shown. The medical instruments 104, 106 can generally correspond to the instruments discussed below, such as instrument 204 disclosed in connection with FIG. 2. For example, the embodiments described herein may be used with a daVinci SP® Surgical System, commercialized by Intuitive Surgical, Inc. of Sunnyvale, California, but such use is not limiting. The schematic illustration of FIG. 1 depicts only two medical instruments for simplicity, but more than two instruments may be mounted in an installed position at a manipulating system as those having ordinary skill in the art are familiar with. Each of instruments 104 and 106 includes an instrument shaft 105 and 107 respectively that, at a distal end portion, has a moveable end effector or an endoscope, camera, or other imaging or sensing device, and may or may not include awrist mechanism (not shown) to control the movement and orientation of the distal end portion.

[0045] In the embodiment of FIG. 1 , the distal end portions of the instruments 104, 106 are received through a single port structure 108 to be introduced into the patient. As shown, the port structure includes a cannula 110 and an instrument entry guide 112 inserted into the cannula 110. Individual instruments 104, 106 are inserted into the entry guide 112 and through the cannula 110 to reach a remote worksite.

[0046] Transmission mechanisms 114, 116 are disposed at a proximal end portion of each instrument shaft 105, 107 and connect to drive assemblies 122, 124, optionally through a sterile adaptor 118, 120. Drive assemblies 122, 124 contain a variety of internal drive devices and other components (not shown) that are controlled by a controller (e.g., at a control interface of the manipulator system) to respond to input commands at a user control system of the manipulator system 100 to transmit force to input drive devices (not shown) of the transmission mechanisms 114, 116 to actuate instruments 104, 106, as described above.

[0047] As shown in FIG. 1 , the instrument shafts 105, 107 are positioned close to one another as they enter the entry guide 112 and extend generally parallel with gradual divergence from one another in the proximal direction, i.e. , toward the transmission mechanisms 114, 116 and the drive assemblies 122, 124. Due to this divergence from one another, the instrument shafts 105, 107 each assume a slight bend (not illustrated in FIG. 1 ), as discussed in greater detail below.

[0048] In some embodiments of the present disclosure, the instrument shafts 105, 107 may exhibit one or more bends when the instruments are in the mounted installed position in the manipulator system 100. Further, the instrument shafts 105, 107 can exhibit simple or compound bends in one or more different bending planes. Schematic illustrations of an instrument shaft having a simple, single bend (e.g., at an angle a ) between two sections of the shaft and an instrument shaft having a compound (multiple bends at angles an) between two or more adjacent sections of the shaft are shown in FIGs. 11 A and 11 B, respectively. While FIG. 11 B illustrates a shaft with two bends, those of ordinary skill in the art would appreciate more than two bends could exist alongthe shaft. FIGs. 2A-2D are various views of an instrument 204 (similar to instrument 304 in FIG. 3) to better illustrate a bent state of an instrument mounted to a manipulator system. FIGS. 2A and 2C are side views (similar to the views of the instruments of FIG.1 ) of the instrument 204, and FIGS. 2B and 2D are end views (similar to the views of the instruments 104, 106 in FIG. 1 ) of instrument 204.

[0049] FIGs. 2A and 2B represent instrument 204 according to the present disclosure in an uninstalled state. In this embodiment, a shaft 205 of the instrument 204 extends distally from the transmission mechanism 214 at a non-orthogonal angle 9. As shown in FIGs. 2A and 2B, in an unmounted position of the instrument, the shaft 205 extends generally straight from the transmission mechanism 214. In FIG. 2C, it can be seen that the shaft 205 assumes a gradual, arc-shaped bend B in the mounted position as it lies in the plane of FIG. 2C. The shaft 205 assumes a compound bend C in the plane of FIG. 2D. The compound bend of the shaft 205 shown in FIG. 2D enables multiple instruments (such as instruments 104, 106 in FIG. 1 ) to be mounted parallel to one another and compensates for the offset required between the transmission mechanism 214 and the entry guide (e.g., entry guide 112 in FIG. 1 ) to enable multiple instruments (e.g., instruments 104 and 106 in FIG. 1 ) to be inserted through the same entry guide. Other combinations of simple and / or compound bends in one or more bending planes are within the scope of the present disclosure. Embodiments of the present disclosure provide shafts with features that facilitate assumption of the desired bend geometry, while maintaining a desired level of axial and rotational stiffness in the shaft.

[0050] The embodiments described herein are not limited to the manipulator system and instrument configurations of FIG. 1 , and various other teleoperated, computer-assisted manipulator configurations may be used with the embodiments described herein. The diameter or diameters of an instrument shaft, wrist mechanism, and end effector are generally selected according to the size of the cannula with which the instrument will be used and depending on the surgical procedures being performed. In various implementations contemplated herein, a diameter of the instrument shaft and portions with relief features may range, for example, from 4 mm to 14 mm, for example, from 6 mm to 14 mm, or for example, from 8 mm to 14 mm.

[0051] Other configurations of manipulator systems that can be used in conjunction with the present disclosure can use several individual manipulator arms. In addition, individual manipulator arms may include a single instrument or a plurality of instruments. Further, as discussed above, an instrument may be a surgical instrument with an end effector or may be a camera instrument or other sensing instrument utilized during a surgical procedure to provide information, (e.g., visualization, electrophysiological activity, pressure, fluid flow, and / or other sensed data) of a remote surgical site.

[0052] Referring now to FIG. 3, a schematic side view of an embodiment of instrument 304 (such as, for example, medical instrument 104, 106, 204) is shown. While aspects of the present disclosure are discussed in the context of medical instruments, embodiments of the present disclosure can be used with various instruments used in surgical or non-surgical procedures. For example, such instruments include those used for diagnosis, therapy, and sensing, including, for example, imaging instruments such as endoscopes and other imaging instruments. Accordingly, medical instruments as used herein encompasses a variety of instruments used in medical, diagnostic, and therapeutic applications. In addition, aspects of the disclosure can have non-surgical applications, such as in other remotely-actuatable instruments for inspection and other industrial uses, general robotic uses, manipulation of non-tissue work pieces, etc.

[0053] The instrument 304 includes a transmission mechanism 314 at a proximal end portion of a shaft 305. In an exemplary embodiment, the transmission mechanism 314 is configured to interface with a manipulating system, such as manipulating system 100 discussed in connection with FIG. 1. Alternatively, the transmission mechanism 314 can be configured to be operated manually, such as for a manual, laparoscopic instrument.

[0054] An end effector 326 is coupled to a distal end portion of the shaft 305. The end effector 326 can be coupled directly to the shaft 305 or may be coupled to the shaft 305 by an optional articulable wrist mechanism 328 (or other articulable structure), which may include one or more articulable joints to impart one or more degrees of freedom of movement to the end effector 326 relative to the shaft 305 (for example, to move the wrist 328 in one or more of pitch and yaw).

[0055] Operation of the end effector 326 can be controlled by manipulation of the transmission mechanism 314, either manually or through drives of a manipulating system (e.g., manipulating system 100 shown in FIG. 1 ). The transmission mechanism 314 includes various mechanical and / or electromechanical devices that transmit motion, energy, and / or signals, e.g., from the manipulating system, or from inputs at the transmission mechanism 314 operable by a user, to the end effector 326. While the end effector 326 shown in FIG. 3 comprises a pair of opposing jaw members, other end effector configurations, such as staplers, clip appliers, ligation tools, and other tools are considered within the scope of this disclosure.

[0056] As noted above, the instrument 304 may also include wrist mechanism 328 to facilitate orienting the end effector 326. For example, the wrist mechanism 328 may comprise one or more articulating joints disposed at a distal end portion of the shaft 305 and couple the end effector 326 to the shaft 305 so that the end effector 326 moves relative to the shaft 305 in one or more degrees of freedom.

[0057] Referring now to FIG. 4, an instrument shaft 405 according to one embodiment of the disclosure is shown. The instrument shaft 405 comprises a tubular structure that includes one or more portions that have relief features that impart flexibility to the shaft 405 while minimizing (e.g., reducing or eliminating) a corresponding increase in axial or rotational compliance. As used herein, the term “tubular, “tube,” and variants thereof refer to a structure with a lateral wall defining an interior hollow portion. The cross- sectional shape of the lateral wall (i.e., shape in a plane normal to the longitudinal axis) is not limited and can be, for example, circular, ovoid, elliptical, polygonal, combinations thereof, or any other shape. In addition, the cross-sectional shape of the lateral wall may be constant along the length of the shaft or may vary along the length of the shaft. The one or more portions can be positioned along the shaft 405 at locations that enable the shaft 405 to assume a slight S-shaped bend configuration when the shaft 405 and corresponding instrument are installed in a manipulator system, such as manipulator system 100 discussed in connection with FIG. 1.

[0058] For example, in the embodiment of FIG. 4, the shaft 405 includes a first portion 430 and second portion 432 each with features (e.g., relief features) configured toimpart flexibility to the shaft 405. The longitudinal position of the first portion 430 and second portion 432 shown in FIG. 4 is exemplary only, and such portions can be at any location along the length of the shaft 405. Further, the shaft 405 can optionally include only one portion, or three or more portions, with relief features. The number of portions, longitudinal extent of the portions, and location of the portions having relief features can be chosen based on a total deflection required for the specific configuration of the surgical instrument and manipulator system. For example, if a relatively greater amount of deflection is desired, a greater number and / or a greater longitudinal extent (i. e. , length) of the portions can be utilized. In some embodiments, the shaft 405 can optionally include relief features along a majority of its length.

[0059] The relief features can comprise a relief formed at least partially or entirely through a wall thickness of the tubular structure of the shaft 405 by way of removal of material of the shaft. For example, the relief features can comprise negative features in the form of by removal of material completely through the thickness of the shaft wall thickness or can be negative features formed partially through the thickness of the shaft wall. In some implementations, such negative features can extend generally around the circumference of the shaft 405 and can have a generally helical pattern such that the shaft remains a single piece. In other exemplary embodiments, the negative features can extend circumferentially and separate the shaft 405 into discrete, but connected, pieces. The relief features can have a configuration that minimizes (e.g., reduces or eliminates) axial and rotational compliance of the shaft when the shaft is in a bent and axially compressed state, such as by virtue of tensioned actuation elements (e.g., cables) that are operably coupled to transmit force from a proximal end portion of the instrument to a moveable component (e.g., wrist and / or end effector) at a distal end portion, as discussed in greater detail in connection with various embodiments describe below. The various negative features, regardless of whether they extend completely or partially through a thickness of the wall, can follow a repeating pattern, referred to herein as a kerf pattern that is followed referred to as a kerf pattern.

[0060] Various configurations of kerf patterns for relief features contemplated by the disclosure allow for an instrument shaft to bend to a predetermined nominal angle whilemaintaining a desired axial stiffness and minimizing rotational backlash (torsional stiffness allowing for torque transmission). Further various kerf patterns permit the desired axial and torsional properties to be maintained through a range of bending of the shaft up to the nominal angle, such that instruments that may not be fully bent to the nominal angle during operation can still exhibit the desired axial and rotational backlash minimizing properties. While allowing for the desired properties through a range of angles from neutral to the nominal angle, the kerf patterns in accordance with various implementations herein also facilitate manufacturing by allowing for relatively larger kerf widths, less kerfs per segment, and efficient patterns that allow for substantially continuous cutting (e.g., laser cutting) with little overlap. Various implementations of kerf patterns are angled relative to the longitudinal axis of the shaft as the relief feature extends around the outer wall surface of the shaft. For example, various configurations use an angle of incline of the kerf pattern that is less than 45 degrees relative to a longitudinal axis of the shaft, as discussed below.

[0061] Referring now to FIG. 5, an enlarged view of a portion (such as portion 430 or 432) of shaft 405 having relief features 434 is depicted and will be discussed for the purposes of discussing further configurations of relief features and terminology to be used. The relief features 434 have a contiguous kerf pattern that extends through the wall of the shaft 405 and around the circumference of the shaft in a generally helical pattern from one or more turns so as to extend along at least portion of a length of the shaft. Each “turn” (434a, 434b, 434c of which are labeled in FIG. 5) of the kerf pattern of the relief feature 434 defines opposite “sides” 435 and 436 of the kerf pattern. In the embodiment of FIG. 5, the opposite sides 435 and 436 represent adjacent helical wraps of the wall of the shaft 405, separated by the kerf pattern, and thus the opposite sides 435 and 436 can be different portions of the same individual component, i.e. , the shaft 405, which remains a single piece since the relief feature 434 is formed helically. In other embodiments, for example, embodiments in which the relief feature 434 is formed as a series of concentric, non-helical reliefs, the opposite sides 435 and 436 could be entirely separate components.

[0062] In various embodiments, if a series of separate kerf patterns are cut in rings around the shaft, they can be generally at a 90-degree angle to the longitudinal axis. In other embodiments the kerf pattern can be angled and follow a helical path so as to exhibit an incline as it follows the helical path around a circumference of the shaft. For example, as shown in FIG. 5A, which is a detailed portion 5A in FIG. 5, the kerf pattern can be inclined at an angle a measured from a line extending perpendicular and transverse to a longitudinal axis of the shaft as shown. As discussed above, in various embodiments, a may range more than 0 degrees to 45 degrees.

[0063] With reference now to FIGs. 6A-6C, a kerf pattern for relief features in accordance with aspects of the disclosure is illustrated in a planar rendering that is shown in isolation and not in its repeating helical form on an instrument shaft. FIG. 6A shows the kerf pattern as cut, FIG. 6B shows the kerf pattern on a compression side of the shaft in a bent state, also depicting the interaction of the interlocking elements formed by the kerf pattern as they would behave on the compression side of a bent shaft, and FIG. 6C shows the kerf pattern and interlocking elements behavior on a tension side of an at least partially bend shaft. Each of FIGs. 6A-6C further includes a detailed view to better illustrate the behavior of one of the kerf elements of the repeating pattern.

[0064] As mentioned above, the kerf pattern 634 creates a plurality of interlocking elements 637, 638 on opposite sides of the relief features 634’ (the negative features where material is removed) and that have complementary configurations configured to engage each other in various ways depending on the state of the shaft. The kerf pattern 634 is such that each interlocking element 637, 638 has a generally rectangular profile that extends from the common, solid (no relief features) portion of the shaft wall on respective opposing sides 635, 636. The kerf pattern 634 includes an angled relief feature 640 (shown best in the detailed views of FIG. 6A) at one of the opposing lateral side walls of the interlocking elements 637, 638. The angled relief feature 640 forms complementary latch features 641 , 642 at the opposing lateral side walls of the interlocking elements 637, 638, which are described in further detail below. The kerf pattern 634 further defines a wider base portion 643, 644 where the interlockingelements 637, 638 meet the respective opposing sides 635, 636 of the solid (no relief features) regions of the shaft wall.

[0065] With reference to FIG. 6B, after the formation of the kerf pattern 634 shown in FIG. 6A, the shaft may be placed in compression to force the end portions of the interlocking elements 637, 638 into contact with the respective opposing sides 636, 635, causing the latching features 641 , 642 to move past each other as shown. Due to the angled configuration of the latching features 641 , 642, the latching features are able to be pushed past each other with sufficient force and, upon release of the external force, the stop surfaces 641 ’, 642’ of the latching features 641 , 642 engage each other to prevent the interlocking elements 637, 638 from moving back to the positions in the initial state of FIG. 6A.

[0066] But due to the locations of the latching features 641 , 642, an amount of play is provided between the ends of the interlocking elements 637, 638 and the respective opposing sides 636, 635 with which they abut in the fully compressed state. This permits a range of motion of the interlocking elements 637, 638 so as to allow for bending of the shaft. FIG. 6C illustrates the positions of the interlocking elements 637, 638 in a neutral (unbent) state of the shaft, with the distance D indicating the range of motion provided.

[0067] In addition to the interaction of the latching features 641 , 642 described above, the wider base portions 643, 644 of the interlocking elements 637, 638, are sized so as to abut the lateral side walls of adjacent and opposite interlocking elements 638, 637, respectively, throughout the range of motion D (see FIGs. 6B and 6C). The abutting of the surfaces of the base portions 643, 644 with the lateral side walls of adjacent interlocking elements 638, 637 (shown by reference label A as representative in the detail view of FIGs. 6B and 6C) may be so as to allow for relative movement without significant friction between the surfaces. In some cases, the fit may have a slight tolerance to avoid physical contact between the surfaces, while generally preventing any significant lateral movement in the directions L shown in FIGs. 6B and 6C between the interlocking elements 637, 638 and opposing sides 635, 636.

[0068] The kerf pattern 634 and the interaction between the formed interlocking elements 637, 638 provides the shaft with torsional stiffness so as to hinder rotational backlash while permitting a degree of bending of the shaft. Moreover, some degree of engagement and interlocking of the interlocking elements occurs through the range of motion D (and thus through the range of bending from the neutral state (FIG. 6C) to the nominal angle (FIG. 6B representing the compression side of the shaft in the bent state). In particular, the engagement of the interlocking elements 637, 638 are designed to be compressed by axial force and can hinder the relative lateral motion L of the opposite sides of 635, 636. The interlocking elements 637, 638 and the latching features and interaction of the base portions 643, 644 described above further provide for a degree of locking of the interlocking elements when the shaft is bent, including on both the tension and compression sides of the bend.

[0069] This design further provides rotational stiffness (e.g., hinders backlash due to twisting of the shaft about a longitudinal axis resulting in movement of portions of the shaft with respect to other portions of the shaft) when the shaft is subjected to a rotational torque, both when the shaft is under axial compression due to being mounted to a manipulator system and placed under a compressive axial load (such as may be provided via cables or other actuation elements coupled to the shaft and pulled to exert an axial compression on the shaft) and when the shaft is not under such an axial compressive load or the compressive load exerted by the actuation element is lessened from the state of the instrument mounted to the manipulator system. Stated differently, the instrument can be unmounted from the manipulator system and the instrument can still provide the interlocking relation of the interlocking elements 637, 638 shown in FIG. 6B.

[0070] In various embodiments, the nominal width of the kerf pattern 634 (in other words the gap between the surfaces of the complementary latch features and the lateral walls of adjacent interlocking elements 637, 638 can range from 0.001 in. to 0.005 in. for example, the width may be for example, about 0.005 in. In an embodiment, the number of spirals of the kerf pattern 634 may range from 5-9, and the angle of incline (pitch) of the spiral (e.g., measured by a as discussed above with respect to FIG. 5A) may befrom 0 degrees (i.e. , no angle of incline) to about 89 degrees, for example, from 0 degrees to about 45 degrees, or less than 45 degrees. The number of pairs of interlocking elements 637, 638 in a spiral (180 degrees around the circumference of the shaft) can range from 5-15, for example, from 6-9 pairs. The range of motion D can be about 0.003 inches to 0.012 inches from the neutral to the compression or tension side in the bent state

[0071] Another configuration of a kerf pattern for relief features of an instrument shaft in accordance with aspects of the disclosure is illustrated in FIGs. 7A-7C, with FIG. 7A illustrating the neutral state (unbent state) of the shaft with the kerf pattern 734, FIG. 7B representing the compression side of the shaft in a bent state, and FIG. 7C representing the tension side of the shaft in a bent state. The kerf pattern 734 forms T-shaped interlocking elements 737, 738 with the stem of the T extending from the respective common portion of the opposing sides 735, 736 of the relief features 734’ of the shaft and the head (cross-bar) of the T at the opposite end of the stem and coming into contact with the respective opposing sides 736, 735, respectively, when in compression (as can be seen in FIG. 7B). In FIGs. 7A-7C, the kerf pattern 734 allows for a degree of play and thus range of motion D to allow for bending of the shaft, similar to that described above with respect to FIGs. 6A-6C. The head portions of adjacent and opposite interlocking elements 737, 738 interfere with each other on the tension side of a bent shaft as depicted in FIG. 7C to ensure the interlocking engagement on both sides of the shaft bent to the nominal predetermined angle.

[0072] In addition, the width W of the head of the T of the interlocking elements 737, 738 is sized to maintain approximate abutment with the stem portions of opposite adjacent interlocking elements 738, 737. This approximate abutment (which can be a nominal spacing between the two elements to provide frictionless relative motion as described above) substantially prevents relative lateral motion L of the interlocking elements 737, 738 and the portions of the shaft on opposing sides 735, 736 of the relief features throughout the bending range of motion and on both the compression (FIG. 7B) and tension (FIG. 7C) sides of the shaft.

[0073] Similar to other embodiments herein, the various interfering surfaces of the interlocking elements 737, 738 provide the interference throughout the range of bending of the shaft from neutral through the predetermined nominal bending angle, and whether or not the shaft is under an external axial compressive loading, such as the axial compressive load caused by tensioned actuation elements.

[0074] In various embodiments, the width of the relief features forming the kerf pattern of FIGs. 7A-7C (in other words the smallest gap between the opposing lateral surfaces of the interlocking elements 737, 738 in the neutral state shown in FIG. 7A), ranges from about 0.001 in. to about 0.005 in., for example, the width may be from about 0.0015 in. to about 0.0025 in., for example, about 0.001 in. In an embodiment, the number of spirals of the kerf pattern 1034 may range from 5-9, for example, 6 or 7, and the angle (pitch) of the spiral relative to a longitudinal axis of the shaft may be from about 0 degrees to about 89 degrees, for example 0 degrees to 45 degrees, or less than 45 degrees. The number of pairs of interlocking elements 737, 738 in a spiral (180 degrees around the circumference of the shaft) can range from 5-15, for example, from 6-9 pairs. The range of motion D per spiral may be 0.003 inches to 0.012 inches from the neutral to the compression or tension side in the bent state.

[0075] FIG. 8 represents another neutral (unbent) state of a kerf pattern for relief features that results in similar kinematics and configurations of the compression and tension sides of the bent shaft as in FIGs. 7B and 7C. Comparing FIG. 8 to FIG. 7A, it can be seen that the kerf pattern 834 provides a larger clearance between the head portions of the T-shaped interlocking elements 837, 838 and the opposing sides 836, 835 with which they respectively abut in compression. In addition, as can be seen best in the detailed view of FIG. 8A-8A, rather than having a uniform width over its length, the stem portion of the T-shaped interlocking elements 837, 838 has a small taper portion that separates a base end portion of the stem portion from the remaining length, with the based end portion having a slightly larger width W1 than the remaining length having width W2 of the stem portion of the interlocking elements 837, 838.

[0076] FIGs. 9A-9C illustrate another configuration of a kerf pattern 934 for relief features 934’ of an instrument shaft in accordance with aspects of the disclosure andthat forms generally T-shaped interlocking elements 937, 938 similar to the embodiments of FIGs. 7 and 8, except that in FIGs. 9A-9C the stem portion of the interlocking element 938 has an enlarged width W2 in a middle region of the length of the stem portion compared to a remaining width of the stem portion and the head portion of the interlocking elements 937 has a non-uniform width along the length, represented by W4 and W5, with W4 being larger than W5. The widths W3 and W4 are such that adjacent interlocking elements 937, 938 substantially abut at those outer surfaces of the respective head portions of interlocking element 937 and stem portions of the neighboring interlocking elements 938 where those widths occur. This close abutment occurs on the compression side of the shaft through the bending range of motion, as can be seen from FIG. 9B. The illustration of FIG. 9A shows the shaft in a neutral state, and FIGs. 9B and 9C show the compression and tension sides of the shaft, respectively, in a bent position of the shaft at the predetermined nominal bend angle. The range of motion D to allow the bending is illustrated in FIG. 9B. Other interferences and resulting interactions / kinematics of the motion of the shaft are similar to those as described above with regard to rotational backlash, axial stiffness, relative lateral motion of the opposite sides of the kerf pattern, etc.

[0077] The various widths of the kerf patterns, the number of spirals and pairs of interlocking elements, range of motion D, and angle of the spirals of FIGs. 8 and 9 may be similar to those set forth for the configuration of FIGs. 7A-7C. Those having ordinary skill in the art will appreciate other permutations of any of the various kerf widths, number of spirals, angles of spirals, number of pairs of interlocking elements, range of motion D may be selected to achieve various design criteria within the scope of the disclosure in view of the configurations of FIGs. 7-9 discussed above.

[0078] Referring now to FIGs. 10A-10C, yet another configuration of a kerf pattern 1034 for relief features 1034’ of a shaft in accordance with aspects of the disclosure is illustrated. In the configuration of FIGs. 10A-10C, the kerf pattern 1034 forms interlocking elements 1037, 1038 that are generally wedge-shaped as they extend from the respective common portions of the shaft on the opposite sides 1035, 1036 of the relief features 1034’. But rather than having a uniform taper from the base of theinterlocking elements 1037, 1038 along the entire length, the interlocking elements 1037, 1038 have a first tapered base portion T 1 extending from the base of the interlocking element 1037, 1038, followed by a flared portion F, followed by a second tapered head portion T2 that terminates at a pointed tip T. Where the flared region F meets the first tapered base portion T1 , a neck N is formed. The relevant profiles are labeled in FIGs. 10A-10D for one of the interlocking element 1037 for ease of illustration, and it can be appreciated that the same parts exist for the interlocking element 1038. Dotted lines are shown to generally distinguish the differing portions T1 , F, T2.

[0079] It should also be noted that the interlocking elements 1037, 1038 are slightly asymmetrical about a line I that bifurcates the angle at the tip portion T of each interlocking element 1037, 1038. The asymmetrical nature changes the distance to close the interlocking elements 1037, 1038 together and the resulting lateral and axial play (range of motion) permitted, allowing modulation of the lateral and axial play in both the compression and tension sides of the shaft in a bent state.

[0080] FIG. 10A shows the kerf pattern 1034 and interlocking elements 1037, 1038 in the neutral (unbent state) of the shaft, while FIGs. 10B and 10C respectively show the compression and tension sides of the shaft bent to a predetermined nominal angle. Referring to FIG. 10B, the complementary interlocking elements 1037, 1038 in engagement conditions associated with a compression side of the shaft in a state of the shaft bent to a predetermined nominal angle are shown. As shown in FIG. 10B, each tapered head portion T2 contacts the opposite side (i.e. , opposite sides 1035 and 1036) between neighboring base portions T1 of adjacent interlocking elements, thereby preventing further relative movement of the opposite sides 1035 and 1036 (and interlocking elements 1037, 1038) toward each other. A small gap G1 is provided in this state between the outer surfaces of adjacent flared portions F.

[0081] Referring to FIG. 10C, the complementary interlocking elements 1037, 1038 in engagement conditions associated with a tension side of the shaft in a state of the shaft bent to a predetermined nominal angle are shown. As shown in FIG. 10C, the outer surfaces of a flared portion F of a respective interlocking element 1037, 1038 engageswith the outer surfaces of neighboring flared portions F on respective adjacent interlocking elements 1038, 1037. Adjacent tapered base portions T1 and head portions T2 are moved out of contact with each other, with a gap G2 provided between the outer surface of those portions. The engagement of the surfaces of adjacent flared portions F on the tension side of the bent shaft prevents additional relative motion of the opposite sides 1035, 1036 away from each other.

[0082] The overall gaps and relative locations of the outer surfaces of the interlocking elements 1037, 1038 provide for a range of relative motion D (see FIG. 10C) of the interlocking elements 1037, 1038 toward and away from the opposite sides 1035, 1036 of the relief features 1034’ of the kerf pattern 1034 while also hindering relative lateral movement in the directions L of the opposite sides 1035, 1036 (and interlocking elements 1037, 1038) throughout the range of motion of bending of the shaft from neutral to the predetermined nominal angle. This provides for rotational stiffness sufficient to substantially hinder rotational backlash over the range of bending motion. Moreover, as with other implementations described above, the kerf pattern of FIGs. 10A-10C locks the shaft in compression and tension sides even in the absence of an external axial compression force (such as tensions actuation elements) acting on the shaft.

[0083] One aspect of the kerf pattern 1034 of FIGs. 10A-10C that assists with ensuring engagement of surfaces to promote locking of the interlocking elements 1037, 1038 on both the compression and tension sides of the shaft in the bent state is the use of differing angles for the outer surfaces of the flared portion F (which mate in tension as illustrated in FIG. 10C) and the tapered head portion T2 (which mate in compression as illustrated in FIG. 10B). Referring again to FIG. 10C, the outer surfaces of the flared portions F may have an angle ©1 relative to the longitudinal axis of the shaft that is less than an angle 02 of the outer surfaces of the head portion T2 relative to the longitudinal axis of the shaft. For example, 01 may be about of 02. In various configurations, each of 01 and 02 may be in a range from 10 degrees to 45 degrees. In one configuration, 01 may be about 15 degrees and 02 about 30 degrees.

[0084] The above surface angles are exemplary only and the angles ©1 and ©2 can be chosen based on a particular application and in consideration of various factors, such as, for example, the coefficient of friction of the material of the shaft, the anticipated loads applied to the shaft, and the like. In some cases, it is desirable to maximize the shaft’s axial movement without causing jamming of the interlocking elements 1037, 1038. For example, although smaller angles for ©1 and ©2 may be desirable to maximize the shaft’s range of axial movement for a given backlash, reducing the angles (i.e., of the surfaces) too much can lead to the interlocking elements 1037, 1038 wedging together so firmly that they jam and are not able or are difficult to separate. In the exemplary application illustrated in FIGs. 10A-10C, because the compression loads are generally higher than the tension loads, to prevent jamming, a larger angle is chosen for ©2 than is chosen for ©1 .

[0085] In various embodiments, the width of the relief features forming the kerf patterns of FIGs. 10A-10B (in other words the gap between the opposing surfaces of the interlocking elements 1037, 1038 shown in FIG. 10A), ranges from about 0.001 in. to about 0.005 in., for example, the width may be from about 0.0015 in. to about 0.0025 in., for example, about 0.002 in. In an embodiment, the number of spirals of the kerf pattern 1034 may range from 5-15 for example, 6-9, and the angle of incline (pitch) of the spiral (a with reference to FIG. 5) may be from about 0 degrees to about 89 degrees, for example about 0 degrees to 45 degrees, or less than 45 degrees... The number of pairs of interlocking elements 1037, 1038 in a spiral (180 degrees around the circumference of the shaft) can range from 5-15, for example, from 6-9 pairs. The range of motion D may be about 0.003 inches to 0.012 inches from the neutral to the compression or tension side in the bent state.

[0086] In some embodiments, the predetermined nominal bend angle corresponds to a bend angle obtained by the shaft when the instrument is mounted on a manipulator system, such as in the configuration of instruments 104, 106 and manipulator system 100 of FIG. 1 , and as discussed with respect to FIGs. 2A-2D. Such bend angles may be, for example, in the range of up to 10 degrees, in the range of up to 20 degrees, or other ranges. In one exemplary embodiment, the bend angle required to install the shaftin the manipulator ranges from 4 degrees to 8 degrees, such as for example, about 6 degrees.

[0087] Further, the predetermined bend angle may encompass a range of predetermined bending angles of the shaft. For example, various factors such as manufacturing tolerances and variations in material characteristics may result in the complementary interlocking engagement members engaging at slightly different bend angles depending on the rotational orientation and external forces applied to the shaft. Thus, while shafts of the present disclosure are described as engaging at a predetermined angle, a person of ordinary skill in the art would understand that such a predetermined angle is subject to normal variation, and the predetermined angles discussed herein are accordingly subject to variations resulting from such factors.

[0088] Further, various configurations, such as the angle of incline of a kerf pattern, the number of interlocking elements per spiral, the number of spirals, the range of motion of the interlocking elements from the neutral state of the shaft to a bent state (on either of the compression or tension side the shaft) can vary and be selected based on factors such as, for example, the nominal bent angle, manufacturing tolerances and requirements, the stiffness desired, among others.

[0089] In addition to providing axial stiffness as described above, the relief features having kerf patterns in accordance with various embodiments can be configured to exhibit rotational stiffness generally equal to the rotational stiffness of the shaft portions that do not include relief features. For example, when the shaft is bent to a predetermined bend angle, the complementary interlocking engagement features defined by the kerf pattern can be configured to engage one another to prevent rotational movement between the complementary interlocking engagement features.

[0090] In other embodiments, the width of the relief features (gaps between surfaces of the formed interlocking elements) of various kerf patterns of the disclosure, including those described above and illustrated, can optionally be consistent throughout the kerf pattern or can be different in different regions of the kerf pattern.

[0091] Various of the kerf patterns illustrated show tips and angled corners along the kerf pattern. It can be appreciated, however, that such corners can include radiuscorners and in some cases enlarged radiuses on the kerf cut out portion can be used as compared to the corresponding mating corner of the interlocking element.

[0092] The relief features and kerf patterns described herein can be achieved by a variety of material removal processes, including, but not limited to for example, laser cutting, waterjet cutting, milling or other machining processes, or combinations of the preceding. In other implementations, additive manufacturing techniques, such as 3-D printing and molding, for example, can be used to manufacture shafts comprising relief features and kerf patterns.

[0093] In some cases, instruments described herein may be configured for use with remotely operated, computer-assisted surgical systems employing robotic technology such as, the da Vinci ® Surgical Systems commercialized by Intuitive Surgical, Inc. of Sunnyvale, California. Although various embodiments described herein are discussed with regard to surgical instruments used with a manipulating system of a computer- assisted surgical system employing robotic technology, the present disclosure is not limited to use with surgical instruments for such surgical systems. For example, various embodiments described herein can optionally be used in conjunction with hand-held, manual or semi-automated surgical instruments, such as those used for manual laparoscopic surgery, or other surgical and non-surgical instruments.

[0094] This description and the accompanying drawings that illustrate exemplary embodiments should not be taken as limiting. Various mechanical, compositional, structural, electrical, and operational changes may be made without departing from the scope of this description and the invention as claimed, including equivalents. In some instances, well-known structures and techniques have not been shown or described in detail so as not to obscure the disclosure. Like numbers in two or more figures represent the same or similar elements. Furthermore, elements and their associated features that are described in detail with reference to one embodiment may, whenever practical, be included in other embodiments in which they are not specifically shown or described. For example, if an element is described in detail with reference to one embodiment and is not described with reference to a second embodiment, the element may nevertheless be claimed as included in the second embodiment.

[0095] For the purposes of this specification and appended claims, unless otherwise indicated, all numbers expressing quantities, percentages, or proportions, and other numerical values used in the specification and claims, are to be understood as being modified in all instances by the term “about,” to the extent they are not already so modified. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.

[0096] It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the,” and any singular use of any word, include plural referents unless expressly and unequivocally limited to one referent. As used herein, the term “include” and its grammatical variants are intended to be non-limiting, such that recitation of items in a list is not to the exclusion of other like items that can be substituted or added to the listed items.

[0097] Further, this description’s terminology is not intended to limit the invention. For example, spatially relative terms — such as “beneath”, “below”, “lower”, “above”, “upper”, “proximal”, “distal”, and the like — may be used to describe one element’s or feature’s relationship to another element or feature as illustrated in the figures. These spatially relative terms are intended to encompass different positions (i.e. , locations) and orientations (i.e., rotational placements) of a device in use or operation in addition to the position and orientation shown in the figures. For example, if a device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be “above” or “over” the other elements or features. Thus, the exemplary term “below” can encompass both positions and orientations of above and below. A device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0098] Further modifications and alternative embodiments will be apparent to those of ordinary skill in the art in view of the disclosure herein. For example, the systems andthe methods may include additional components or steps that were omitted from the diagrams and description for clarity of operation. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the present teachings. It is to be understood that the various embodiments shown and described herein are to be taken as exemplary. Elements and materials, and arrangements of those elements and materials, may be substituted for those illustrated and described herein, parts and processes may be reversed, and certain features of the present teachings may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of the description herein. Changes may be made in the elements described herein without departing from the spirit and scope of the present teachings and following claims.

[0099] It is to be understood that the particular examples and embodiments set forth herein are non-limiting, and modifications to structure, dimensions, materials, and methodologies may be made without departing from the scope of the present teachings.

[0100] Other embodiments in accordance with the present disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the following claims being entitled to their fullest breadth, including equivalents, under the applicable law.

Claims

CLAIMSWHAT IS CLAIMED IS:

1. An instrument, comprising: a tubular shaft comprising a longitudinal axis; an end effector coupled to a distal end portion of the shaft; and relief features in a wall of the shaft and extending around a circumference of the shaft along at least a portion of a length of the shaft, the relief features having a kerf pattern defining complementary interlocking elements on opposite sides of the relief features, wherein: the complementary interlocking elements move relative to one another in response to bending of the shaft, and the complementary interlocking elements comprise surface portions engaging each other over a range of bend angles of a bent region of the shaft from neutral through a predetermined bend angle at both a tension side and a compression side of the bent region of the shaft.

2. The instrument of claim 1 , wherein the surface portions engage each other over the range of bend angles in the absence of an external compressive axial load on the shaft.

3. The instrument of any of claims 1 and 2, wherein the kerf pattern follows a helical pattern around the circumference of the shaft.

4. The instrument of claim 3, wherein a number of spirals in the helical pattern ranges from 5-15.

5. The instrument of claim 4, wherein the kerf pattern is configured to provide an axial range of relative motion between the complementary interlocking elements ranging from 0.003 in. to0.012 in. per spiral over a range of bending of the shaft from a neutral state to a bent state of the shaft.

6. The instrument of claim 3, wherein spirals of the helical pattern are angled in a range from 0 to 89 degrees relative to a plane perpendicular to the longitudinal axis of the shaft.

7. The instrument of any of claims 1 and 2, wherein each complementary interlocking element comprises a generally wedge-shaped profile comprising tapered base portion, a flared portion extending from the tapered base portion, and a tapered head portion extending from the flared portion.

8. The instrument of claim 7, wherein an angle of taper of the tapered head portion of each complementary interlocking element ranges from 10 degrees to 45 degrees.

9. The instrument of claim 7 or 8 , wherein an angle of taper of the tapered base portion of each complementary interlocking element ranges from 10 degrees to 45 degrees.

10. The instrument of any of claims 1 and 2, wherein the predetermined bend angle is from 4 degrees to 8 degrees.11 . The instrument of any of claims 1 and 2, wherein the nominal width of a relief feature of the kerf pattern ranges from 0.001 in. to 0.005 in.

12. The instrument of any of claims 1 and 2, wherein the instrument is a medical instrument configured to be mounted to a manipulator system of a teleoperated, computer-assisted surgical system.

13. An instrument, comprising: a tubular shaft having a longitudinal axis; an end effector coupled to a distal end portion of the shaft; and relief features in a wall of the shaft and extending around a circumference of the shaft along at least a portion of a length of the shaft, the relief features having a kerfpattern defining complementary interlocking elements on opposite sides of the relief features; wherein, on a condition that the shaft is in a neutral position, the kerf pattern defines a gap between the complementary interlocking elements on opposite sides of the relief features, the gap varying in width at different locations of the relief features; and wherein, on a condition that the shaft is bent to an angle within a range of bending angles from neutral through a predetermined bend angle, complementary surface portions of the complementary interlocking elements engage one another and prevent lateral movement of the complementary interlocking elements relative to one another about the longitudinal axis.

14. The instrument of claim 13, wherein the complementary surface portions engage each other over the range of bend angles in the absence of an external compressive axial load on the shaft.

15. The instrument of any of claims 13 and 14, wherein the kerf pattern follows a helical pattern around the circumference of the shaft.

16. The instrument of claim 15, wherein a number of spirals in the helical pattern ranges from 5-15.

17. The instrument of claim 16, wherein the kerf pattern is configured to provide an axial range of relative motion between the complementary interlocking elements ranging from 0.003 in. to 0.012 in. per spiral over a range of bending of the shaft from a neutral state to a bent state of the shaft.

18. The instrument of claim 15, wherein spirals of the helical pattern are angled in a range from 0 to 89 degrees relative to a plane perpendicular to the longitudinal axis of the shaft.

19. The instrument of any of claims 13 and 14, wherein each complementary interlocking element comprises a generally wedge-shaped profile comprising tapered base portion, a flared portion extending from the tapered base portion, and a tapered head portion extending from the flared portion.

20. The instrument of claim 19, wherein an angle of taper of the tapered head portion of each complementary interlocking element ranges from 0 degrees to 45 degrees.21 . The instrument of any of claims 19, wherein an angle of taper of the tapered base portion of each complementary interlocking element ranges from 0 degrees to 45.

22. The instrument of any of claims 13 and 14, wherein the predetermined bend angle is from 4 degrees to 8 degrees.

23. The instrument of any of claims 13 and 14, wherein the nominal width of a relief feature of the kerf pattern ranges from 0.001 in. to 0.005 in.

24. The instrument of any of claims 13 and 14, wherein the instrument is a medical instrument configured to be mounted to a manipulator system of a teleoperated, computer-assisted surgical system.

25. A method comprising: bending a portion of a shaft from a neutral, unbent state of the portion of the shaft to an angle in a range from neutral to a predetermined nominal angle; in response to bending, engaging complementary surfaces of complementary interlocking elements defined by a kerf pattern of relief features in a wall of the shaft; and preventing, from the engaging, relative lateral motion of the complementary surfaces on a tension side and a compression side of the portion of the shaft bent from the bending.

26. The method of claim 25, wherein engaging the complementary surfaces of the complementary interlocking elements comprises engaging complementary surfaces on a compression side and a tension side of the portion of the shaft bent to the predetermined nominal angle from the bending.

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