Patent Description:
Remotely controlled surgical instruments, including teleoperated surgical instruments (e.g., surgical instruments operated at least in part with computer assistance, such as instruments operated with robotic technology), are often used in minimally invasive medical procedures. During medical procedures, portions of surgical instruments may be moved in one or more directions, such as via teleoperated (remote control) or manual operation. For instance, the surgical instrument may be actuated by a mechanical force transmission mechanism, located at a proximal end of the surgical instrument shaft, to orient, position, and operate an end effector, located at a distal end of the surgical instrument shaft, in a desired location. The surgical instrument may further include a wrist, such as a jointed, articulatable structure, to which the end effector is connected so that the end effector may be oriented relative to the shaft. The surgical instrument may further include one or more electrical or mechanical end effector actuation elements that pass through the surgical instrument, including through the wrist, to actuate the end effector in order to effect a surgical procedure.

International <CIT>, claiming priority to <CIT>) (entitled "Mechanical Joints, and Related Systems and Methods"), describes actuation elements extending along twisted paths. Bending (e.g., articulating) a wrist, which may support an end effector on a shaft, may result in bending of actuation element(s) that control movement of the end effector, which may cause a change in a path length of the end effector actuation element(s). Such a change in length can result in unintended motions and/or actuations of the end effector. In view of this, it is desirable to provide a surgical instrument that includes an actuation element guide to support one or more end effector actuation elements in a manner that substantially conserves a path length of the actuation element(s) when a wrist of the instrument is articulated. Further it is desirable to provide such an actuation element guide that is relatively easy to manufacture.

<CIT> discloses a surgical manipulator includes an internal working end having an internal joint, and an external control interface linked to the internal working end for controlling the internal working end. The external control interface includes at least one lever defining a grip volume for a surgeon's hand when gripping and operating the at least one lever, and an external joint linked to the internal joint for controlling the internal joint. The external joint is positioned substantially within the grip volume.

<CIT> discloses a needle electrode deployment shaft includes a central member and a plurality of needle electrodes. The central member has a plurality of needle advancement channels formed therein. The needle electrodes are disposed within the advancement channels and each advancement channel terminates in a ramp portion which deflects the needles radially outwardly as they are axially advanced. The ramps may be spirally or acutely configured in order to increase the distance through which the needles may be bent as they are axially advanced. Additionally, the central member may have a radially reduced distal tip in order to decrease tissue insertion forces.

<CIT> discloses a surgical end effector that includes a clevis and two jaws pivotally coupled to the clevis. A wire is coupled to each jaw and extended through a guide way in the other jaw and through an end of the clevis. The jaws may be opened and closed by pushing and pulling on the two cables. Pulling on each wire creates a closing force in both jaws. A rocking pin may be pivotally supported by the clevis and pivotally coupled to the jaws to constrain the jaws to have opposite motions. The clevis may be coupled to an elongate shaft and the wires extended through the shaft to provide an endoscopic instrument. A wire guide may support the wires in the shaft such that they are able to transmit a compressive force without buckling. The wires may carry electricity to the jaws for electrocautery.

<CIT> discloses a tubular medical instrument that can be used for insertion into body cavities for example into the bile duct or the pancreatic duct. It consists of a flexible inner tube and a flexible external tube enclosing the inner tube. Channels are formed in one of the confronting surfaces of the tubes. The channels may be formed by an extrusion process, and the inner tube may have a rolled surface. The channels are used to house optical fibres, or for actuating rods and wires.

<CIT> discloses a medical device shaft that includes a first longitudinal edge joined to all or a portion of a second longitudinal edge, and an inner surface forming a plurality of lumens separated by a plurality of longitudinal ribs extending along a length of the shaft; wherein a base of each rib is spaced apart from one another and each rib is joined to one another in proximity to a peak of each rib. Each of a plurality of elongated members extends within one of the plurality of lumens of the shaft.

<CIT>, in particular Fig. <NUM> with paragraph <NUM>, teaches an actuation element guide with an inner piece comprising guide channels defining a twisted path and an outer piece in form of an outer tube.

<CIT> discloses a multilumen body comprising an inner piece with projections and recesses and an outer piece with projections and recesses together defining guide channels.

The present invention provides an actuation element guide for a surgical instrument and a medical device as set out in the appended independent claim. 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 will become apparent from the description that follows.

In accordance with at least one exemplary embodiment, an actuation element guide for a surgical instrument comprises a first piece, a second piece, at least one guide channel defining a twisted path about a longitudinal axis of the guide. A cross-section of the at least one guide channel, at a location along an axial length of the guide, is defined by a surface portion of the first piece and by a surface portion of the second piece.

A method is also described that is directed to manufacturing an actuation element guide for a surgical instrument. The actuation element guide defines at least one guide channel defining a twisted path about a longitudinal axis of the guide. The method comprises assembling a first piece and a second piece together. The assembling the first piece and the second piece together further comprises defining the at least one guide channel such that a cross-section of the at least one guide channel in a plane perpendicular to the longitudinal axis of the guide comprises at least a first surface portion of the first piece and a second surface portion of the second piece.

In accordance with at least one exemplary embodiment, a medical device comprises a shaft comprising a distal end, a surgical end effector comprising a movable component, a flexible actuation element guide, and an actuation element. The flexible actuation element guide comprises an inner piece and an outer piece surrounding the inner piece. The guide is positioned between the distal end of the shaft and the surgical end effector. A guide channel is between the inner piece and the outer piece. The guide channel twists around a longitudinal centerline of the guide. The actuation element comprises a distal end. The actuation element extends through the guide channel. The distal end of the actuation element is mechanically coupled to the movable component of the end effector.

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.

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 serve to explain certain principles and operation.

This description and the accompanying drawings that illustrate exemplary embodiments should not be taken as limiting. In some instances, well-known structures and techniques have not been shown or described in detail so as not to obscure the disclosure. 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.

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.

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.

Further, this description's terminology is not intended to limit the disclosure or claims. 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 <NUM> degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In accordance with various exemplary embodiments, the present disclosure contemplates actuation element guides (e.g., actuation element supports) that include a first piece, a second piece, and one or more guide channels. For example, the first piece is an inner piece and the second piece is an outer piece that surrounds the first piece. A cross-section of a guide channel, at a location along an axial length of the guide, is defined by at least surface portions of the first piece and the second piece, according to an exemplary embodiment. According to various exemplary embodiments, assembling an actuation element guide from at least two pieces facilitates manufacture of the actuation element guide in a more efficient manner, such as by permitting more efficient manufacturing processes to be used to manufacture the pieces from which the guide is assembled.

In accordance with the invention, a guide channel defines a twisted path about a longitudinal axis of the guide. The twisted path guides and/or supports a mechanical actuation element extending along the channel such that a path length of the actuation element does not substantially change, such as when the guide is bent, in accordance with various exemplary embodiments. Surfaces of at least the first piece and the second piece cooperate to define channel along at least a portion of the twisted path. According to an exemplary embodiment, surface of one of the first piece and the second piece include radially extending projections that extend between the first piece and the second piece. The projections have a spoke-like configuration, according to an exemplary embodiment. In one example, the second piece surrounds the first piece and the projections radially extend from an inner surface of the second piece and contact an outer surface of first piece. The first piece can have grooves to receive ends of the projections radially extending from the inner surface of the second piece. The first piece can have cylindrical cross-section. In another example, the second piece surrounds first piece and the projections extend from an outer surface of the first piece and contact an inner surface of the second piece. The second piece can have grooves to receive ends of the projections. The second piece can have cylindrical cross-section. In accordance with at least one exemplary embodiment, an actuation element guide includes a cutout to facilitate bending of the actuation element guide. According to an exemplary embodiment, the cutout is a recess located in an outer radial surface of the actuation element guide.

According to various exemplary embodiments, an actuation element guide includes a first portion and a second portion disposed in an end-to-end manner along a longitudinal proximal-distal direction of the guide, according to an exemplary embodiment. For example, the first portion includes longitudinally straight guide channels and the second portion includes twisted channels with respect to the longitudinal axis of the guide, wherein the second portion includes the first piece and the second piece of the actuation element guide. According to an exemplary embodiment, the first portion is disposed within an instrument where bending is minimal or does not occur (e.g., a shaft of an instrument) while the second portion is disposed within an instrument where bending occurs (e.g., a wrist of an instrument). According to an exemplary embodiment, the actuation element guide includes one or more port openings disposed in a lateral side of the actuation element guide. A port opening provides access to an interior region of the actuation element guide. An actuation element extends within the interior region of the actuation element guide, exit the actuation element guide via the port opening, and extend extends along at least a portion of an instrument shaft outside of the actuation element guide, according to an exemplary embodiment.

In accordance with at least one exemplary embodiment, a method of manufacturing an actuation element guide for a surgical instrument includes assembling a first piece and a second piece together. According to an exemplary embodiment, each of the first piece and the second piece is formed via, for example, molding, extruding or another technique. The assembling of the first piece and the second piece includes assembling the first and second pieces together so that surface portions of the first piece and second piece define a cross section of at least one channel defining a twisted path about a longitudinal axis of the guide. According to an exemplary embodiment, the first and second pieces are joined to one another. Joining the first piece and the second piece includes laser welding, according to an exemplary embodiment. According to an exemplary embodiment, joining the first piece and the second piece includes inserting the first piece within the second piece, wherein the second piece includes a transparent or translucent material configured to transmit energy from a laser through the second piece to the first piece.

Referring now to <FIG>, an exemplary embodiment of a patient side cart <NUM> of a teleoperated surgical system is shown. A teleoperated surgical system can further include a surgeon console (not shown) for receiving input from a user to control instruments mounted at patient side cart <NUM>. A teleoperated surgical system also can include an auxiliary equipment/vision cart (not shown), which can optionally include at least part of the system's computer control equipment, as described in, for example, U. Patent Application Pub. No. <CIT>, and U. Patent Application Pub. Further, the exemplary embodiments described herein may be used, for example, with a da Vinci® Surgical System, such as the da Vinci Si® Surgical System, or the da Vinci Xi® Surgical System, both with or without Single-Site® single orifice surgery technology, all commercialized by Intuitive Surgical, Inc.

Patient side cart <NUM> includes a base <NUM>, a main column <NUM>, and a main boom <NUM> connected to main column <NUM>. Patient side cart <NUM> may also include a plurality of teleoperated manipulator arms <NUM>, <NUM>, <NUM>, <NUM>, which are each connected to main boom <NUM>, according to an exemplary embodiment. Manipulator arms <NUM>, <NUM>, <NUM>, <NUM> may each include an instrument mount portion <NUM> to which an instrument <NUM> may be mounted, which is illustrated as being attached to manipulator arm <NUM>. Portions of manipulator arms <NUM>, <NUM>, <NUM>, <NUM> are manipulated during a surgical procedure according to commands provided by a user at the surgeon console. In an exemplary embodiment, signal(s) or input(s) transmitted from a surgeon console are transmitted to the control/vision cart, which interprets the input(s) and generate command(s) or output(s) to be transmitted to the patient side cart <NUM> to cause manipulation of an instrument <NUM> (only one such instrument being mounted in <FIG>) and/or portions of manipulator arm <NUM> to which the instrument <NUM> is coupled at the patient side cart <NUM>.

Instrument mount portion <NUM> may include an actuation interface assembly <NUM> and a cannula mount <NUM>. A shaft <NUM> of instrument <NUM> extends through cannula mount <NUM> and on to a surgery site during a surgical procedure. A force transmission mechanism <NUM> of instrument <NUM> is mechanically coupled with the actuation interface assembly <NUM>, according to an exemplary embodiment. Cannula mount <NUM> is configured to hold a cannula (not shown) through which shaft <NUM> of instrument <NUM> may extend to a surgery site during a surgical procedure. Actuation interface assembly <NUM> contains a variety of drive and other mechanisms that are controlled to respond to input commands at the surgeon console and transmit forces to the force transmission mechanism <NUM> to actuate instrument <NUM>, as those skilled in the art are familiar with.

Although the exemplary embodiment of <FIG> shows an instrument <NUM> attached to only manipulator arm <NUM> for ease of illustration, an instrument may be attached to any and each of manipulator arms <NUM>, <NUM>, <NUM>, <NUM>. An instrument <NUM> may be a surgical instrument with an end effector or may be an endoscopic imaging 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. In the exemplary embodiment of <FIG>, a surgical instrument with an end effector or an imaging instrument may be attached to and used with any of manipulator arms <NUM>, <NUM>, <NUM>, <NUM>. However, the embodiments described herein are not limited to the exemplary embodiment of the patient side cart of <FIG>, and various other teleoperated surgical system configurations, including patient side cart configurations, may be used with the exemplary embodiments described herein.

Turning to <FIG>, a schematic side view of an exemplary embodiment of a surgical instrument <NUM> is shown. For instance, surgical instrument <NUM> is used as instrument <NUM> with the patient side cart <NUM> of the exemplary embodiment of <FIG>. Surgical instrument <NUM> includes a force transmission mechanism <NUM> (a chassis <NUM> which is shown in the exemplary embodiment of <FIG>, with a housing not being shown to reveal components of the force transmission mechanism <NUM> within), a shaft <NUM> connected to force transmission mechanism <NUM> at a proximal end <NUM> of shaft <NUM>, a wrist <NUM> connected to a distal end <NUM> of shaft <NUM>, and an end effector <NUM> connected to wrist <NUM>, according to an exemplary embodiment. According to an exemplary embodiment, shaft <NUM> is flexible. Various diameters for shaft <NUM> may exist in a range suitable for minimally invasive surgery. According to an exemplary embodiment, shaft <NUM> has a diameter ranging from about <NUM> to about <NUM>. For example, shaft <NUM> has a diameter of <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>. According to another exemplary embodiment, the diameter of shaft <NUM> ranges, for example, from about <NUM> to about <NUM>.

Surgical instrument <NUM> may include one or more members to transmit force between force transmission mechanism <NUM> and end effector <NUM> and/or between force transmission mechanism <NUM> and wrist <NUM>. For example, actuation elements <NUM>, <NUM> connect force transmission mechanism <NUM> to end effector <NUM> to provide actuation forces to end effector <NUM>, such as by extending through an interior of shaft <NUM>. By using actuation elements <NUM>, <NUM>, force transmission mechanism <NUM> actuates end effector <NUM> to control, for example, a jaw of end effector <NUM> (or other moveable part of end effector <NUM>). In another example, actuation elements <NUM>, <NUM> are used to actuate wrist <NUM> in one or more orientation degrees of freedom (e.g. pitch and/or yaw). Actuation elements <NUM>, <NUM> may be tension elements, such as when force transmission mechanism <NUM> is a pull-pull mechanism, or one or more actuation element rods or push rods, such as when force transmission mechanism <NUM> is a push-pull mechanism, as described in <CIT>).

Force transmission mechanism <NUM> may include one or more components to engage with a patient side cart of a teleoperated surgical system to transmit a force provided by patient side cart to surgical instrument <NUM>. Persons skilled in the art will be familiar with surgical instrument force transmission mechanisms, which receive a mechanical input force from a power source (e.g., an electric motor from a manipulator supporting the instrument) and convert and/or redirect the received force to an output force to drive a component (e.g., a wrist, and end effector) on the instrument. For example, force transmission mechanism <NUM> connects with the actuation interface assembly <NUM> of the patient side cart <NUM> of the exemplary embodiment of <FIG> so actuation interface assembly <NUM> transmits forces to force transmission mechanism <NUM> to actuate instrument <NUM>. According to an exemplary embodiment, force transmission mechanism <NUM> includes one or more actuation input mechanisms <NUM>, <NUM> that engage (e.g., via a distal end of force transmission mechanism <NUM>) with a manipulator of a patient side cart, such as actuation interface assembly <NUM> of patient side cart <NUM>. When force transmission mechanism <NUM> is a pull-pull mechanism and actuation elements <NUM>, <NUM> are tension elements, actuation input mechanisms <NUM>, <NUM> are capstans that are rotationally driven by actuation interface assembly <NUM> to tension actuation elements <NUM>, <NUM> to actuate instrument, according to an exemplary embodiment. Thus, actuation input mechanisms <NUM>, <NUM> utilize actuation forces from an actuation interface assembly to actuate instrument <NUM>. Force transmission mechanism <NUM> may include other actuation input mechanisms to actuate various other functionalities of a surgical instrument, as those having ordinary skill in the art are familiar with.

Bending may have an effect upon actuation elements when the actuation elements pass through bent portions of a surgical instrument. For instance, bending wrist <NUM> of instrument <NUM> of the exemplary embodiment of <FIG> may have an effect upon actuation elements <NUM>, <NUM>, such as when actuation elements <NUM>, <NUM> extend through wrist <NUM> to end effector <NUM>. For illustrative purposes, <FIG> is an illustrative schematic perspective view of a single flexible member <NUM> that can bend, with axes <NUM>, <NUM> indicating directions of bending, similar to how a wrist of a surgical instrument is bent. A first actuation element <NUM> and a second actuation element <NUM> extend through member <NUM>, such as along a longitudinal axis <NUM> of member <NUM>. In the exemplary embodiment of <FIG>, wherein member <NUM> is in a straight (neutral) configuration, an axis <NUM> passes through each of first actuation element <NUM> and second actuation element <NUM>, such as along the Z axis in the exemplary embodiment of <FIG>. As shown in <FIG>, when member <NUM> is bent, with axis <NUM> indicating a direction member <NUM> is bent in, first and second actuation elements <NUM>, <NUM> bend as well. There is no relative change in path length between first actuation element <NUM> and second actuation element <NUM> because actuation element <NUM>, <NUM> are bent in the same manner. According to an exemplary embodiment, the path length of actuation elements <NUM>, <NUM> is the length each element <NUM>, <NUM> traverses from one end of member <NUM> to another. For example, each of actuation elements <NUM>, <NUM> is fixed relative to member <NUM> and a length of each actuation element <NUM>, <NUM> does not change but the path an actuation element <NUM>, <NUM> traverses along member <NUM> may change when member <NUM> is bent. Thus, when member <NUM> is bent, a path of one of actuation elements <NUM>, <NUM> along member <NUM> does not become substantially longer or substantially shorter than the path of the other.

Referring again to <FIG>, a second axis <NUM> for member <NUM> passes between first actuation element <NUM> and second actuation element <NUM>, such as along the Y axis in the exemplary embodiment of <FIG>. When member <NUM> is bent in the manner shown in <FIG>, with axis <NUM> indicating a direction of bending, first actuation element <NUM> is stretched relative to its neutral position, causing a positive change in a length of its path along member <NUM>, while second actuation element <NUM> is compressed relative to its neutral position, causing a negative change in a length of its path along member <NUM>. Therefore, bending member <NUM> in the manner shown in the exemplary embodiment of <FIG> can cause a change in the relative path lengths of actuation elements <NUM>, <NUM>, with one actuation element becoming longer the other. Such a relative change in path length can interfere with the function of actuation elements, such as to actuate an end effector. For instance, when actuation elements <NUM>, <NUM> are used to open and close an end effector by applying tension to actuation elements <NUM>, <NUM>, similar to actuation elements <NUM>, <NUM> of the exemplary embodiment of <FIG> (e.g., so that ends of actuation elements <NUM>, <NUM> are fixed to the end effector and a force transmission mechanism, such as actuation input mechanisms <NUM>, <NUM> of <FIG>), a relative change in path length between actuation elements <NUM>, <NUM> may create tension, which may result in actuation of the end effector, or may create slack in one of the actuation elements <NUM>, <NUM>, diminishing the ability of the actuation element to transmit the desired tension and cause a desired actuation of an end effector.

It may be desirable to design a joint of a surgical instrument to minimize relative changes in path lengths of actuation elements extending through the joint. For instance, a single actuation element is provided to actuate an end effector, with the single actuation element extending along a centerline of a surgical instrument. In such a configuration, axes defining directions of bending are substantially orthogonal to one another (e.g., axes <NUM>, <NUM> in the exemplary embodiment of <FIG>), such as to provide two degrees of freedom for bending a surgical instrument, and pass through the center of the instrument and the actuation element. As a result, the path length of the single actuation element does not substantially change when the surgical instrument is bent. However, although this approach can be useful when a single actuation element is sufficient to control an end effector, a surgical instrument may include multiple actuation elements, such as to actuate different components of the instrument, including an end effector and a wrist of an instrument, among others. In view of these considerations, it is desirable to extend actuation elements along a twisted path to substantially conserve the path lengths of actuation elements that are positioned off a neutral axis. For example, actuation elements extend along twisted paths according to the various exemplary embodiments described in International <CIT>, claiming priority <CIT>) (entitled "Mechanical Joints, and Related Systems and Methods").

Various exemplary embodiments contemplate one or more structures that guide one or more actuation elements along a twisted path, as described in the exemplary embodiments noted above. One or more structures may provide support to an actuation element and guide the actuation element along its length, such as to minimize or reduce buckling of the actuation element as the actuation element extends along the twisted path according to the exemplary embodiments noted above.

<FIG> shows a distal portion of a surgical instrument that includes an actuation element guide <NUM> (e.g., actuation element support) located at a distal end of an instrument shaft, such as at distal end <NUM> of shaft <NUM> in the exemplary embodiment of <FIG>. According to an exemplary embodiment, a first portion <NUM> of actuation element guide <NUM> includes twisted passages <NUM>, <NUM> that provide a twisted path for actuation elements <NUM>, <NUM> that extend through passages <NUM>, <NUM> of first portion <NUM>. Actuation elements <NUM>, <NUM> extend out of a proximal end <NUM> of first portion <NUM> and into a second portion <NUM> of actuation element guide <NUM>, according to an exemplary embodiment. Second portion <NUM> includes substantially straight passages <NUM>, <NUM> through which actuation elements <NUM>, <NUM> extend, as shown in the exemplary embodiment of <FIG>. Although only two passages <NUM>, <NUM> are depicted within section portion <NUM> in the exemplary embodiment of <FIG> for ease of illustration, second portion <NUM> of actuation element guide <NUM> includes the same number of passages as first portion <NUM>, according to an exemplary embodiment. According to an exemplary embodiment, the passages of second portion <NUM> are joined to the passages of first portion <NUM> so that any actuation elements extending through the passages of second portion <NUM> extend through corresponding passages in first portion <NUM>.

According to various exemplary embodiments, actuation element guide <NUM> includes various numbers of passages to provide a twisted path for one or more actuation elements. For instance, actuation element guide <NUM> may include one passage, two passages, three passages, or four or more passages. For instance, actuation element guide <NUM> may include a third passage <NUM> and a fourth passage <NUM>, which may be used for additional actuation elements or for flux conduits <NUM>, <NUM>, such as electrical conductors to provide electrical energy to an end effector (not shown).

According to an exemplary embodiment, guide <NUM> further includes a central passage <NUM> through which an actuation element <NUM> extends. Central passage <NUM> extends along a longitudinal centerline <NUM> of an instrument including guide <NUM> so that any member extending through central passage <NUM>, such as actuation element <NUM> or a flux conduit, does not experience a substantial change in path length when guide <NUM> is bent, according to an exemplary embodiment. Centerline <NUM> is also a centerline of guide <NUM>, according to an exemplary embodiment. Actuation element <NUM> is used, for example, to actuate an end effector or component of an end effector, such as a cutting blade in an exemplary embodiment.

The actuation elements of the various exemplary embodiments described herein that are radially offset from a neutral axis or centerline (e.g., centerline <NUM> in <FIG>) may be used to actuate various instrument components. For example, the actuation elements of the various exemplary embodiments described herein that are radially offset from a neutral axis or centerline actuate a wrist distal to actuation element guide <NUM>. In another example, the actuation elements are radially offset from a neutral axis or centerline and actuate another instrument component than a wrist. For instance, actuation element <NUM> is used to actuate an end effector, while actuation elements <NUM>, <NUM> are used to actuate the wrist that end effector is connected to. According to another example, a flux conduit extends through central passage <NUM> instead of actuation element <NUM>.

In contrast to passages <NUM>-<NUM>, central passage is located along the longitudinal centerline <NUM> of an instrument, as shown in <FIG>, according to an exemplary embodiment. Because central passage <NUM> is located along longitudinal centerline <NUM>, actuation elements <NUM>, <NUM> and their respective passages <NUM>, <NUM> are radially offset from centerline <NUM>. Thus, when a wrist is actuated to bend an instrument, actuation elements <NUM>, <NUM> could experience a change in path length, without measures to minimize or prevent the change in path length. However, guide <NUM> imparts a twisted path to actuation elements <NUM>, <NUM> within first portion <NUM> (such as according to the exemplary embodiments of International <CIT>, claiming priority <CIT>) so that actuation elements <NUM>, <NUM> do not experience a substantial change in path length over the length of a wrist.

According to an exemplary embodiment, an actuation element guide is positioned in a surgical instrument (e.g., wrist <NUM> in <FIG>) so that the location of the guide corresponds to the location of a wrist because the wrist can bend, which could cause actuation elements extending through the wrist to change in path length. For example, first portion <NUM> of guide <NUM>, which includes twisted passages <NUM>-<NUM>, is positioned within a wrist of an instrument (e.g., wrist <NUM> of the exemplary embodiment of <FIG>) and second portion <NUM> of guide <NUM>, which includes straight passages, is positioned within a shaft of an instrument proximal to the wrist (e.g., shaft <NUM> of the exemplary embodiment of <FIG>). Thus, twisted passages <NUM>-<NUM> of first portion <NUM> provide a twisted path so actuation elements extending through passages <NUM>-<NUM> (which is used to actuate, for example, an end effector or the wrist) do not experience a substantial change in path length, such as when the wrist is articulated. Further, because passages <NUM>, <NUM> of second portion <NUM> are located within the shaft and do not experience a significant amount of bending, passages <NUM>, <NUM> are straight, according to an exemplary embodiment.

As shown in the exemplary embodiment of <FIG> (which is a transverse cross-sectional view of guide <NUM> of <FIG>), actuation element guide <NUM> has a solid, single-piece construction with passages <NUM>-<NUM> formed through the length of guide <NUM>. According to an exemplary embodiment, actuation element guide <NUM> is manufactured, for example, by extruding a polymer material into a substantially cylindrical shape or by molding guide <NUM>. Twisted passages <NUM>-<NUM> are formed through the length of the polymer material by heat forming the extruded material into a twisted shape, such as the shape of first portion <NUM> in the exemplary embodiment of <FIG>, according to an exemplary embodiment. Thus, guide <NUM> may guide one or more actuation elements along a twisted path to substantially conserve the path length of the actuation element(s) and to provide support to the actuation element(s) so buckling of the actuation elements is minimized or prevented.

In various exemplary embodiments, guide <NUM> is flexible to promote bending of guide <NUM> when a wrist that guide <NUM> extends through is actuated. Guide <NUM> is made from, for example, a polymer material to provide a relatively low coefficient of friction. According to an exemplary embodiment, guide <NUM> is made of, for example, polyether block amide (PEBAX), fluorinated ethylene propylene (FEP), and other polymer materials having a relatively low coefficient of friction, including elastomers, familiar to one of ordinary skill in the art.

As discussed above with regard to the exemplary embodiment of <FIG>, an actuation element guide may have a single-piece construction. For instance, the guide is a single piece that has been extruded and shaped to include at least a portion with twisted passages. Although such an actuation element guide may be effective for supporting one or more actuation element(s) along a twisted path, it may be desirable to provide an actuation element guide that facilitates manufacture and is still effective to support one or more actuation element(s) along a twisted path. Therefore, other manufacturing methods may be utilized to provide a guide having one or more twisted passages radially offset from and twisting about a centerline of a guide.

According to an exemplary embodiment, an actuation element guide is manufactured by joining two or more separate pieces together to form the actuation element guide. Turning to <FIG>, an embodiment of an actuation element guide <NUM> is shown, according to the present invention. Actuation element guide <NUM> includes a plurality of channels <NUM>-<NUM>. Channel <NUM> may be a substantially straight channel that extends along a longitudinal centerline <NUM> of guide <NUM> (which may also be the centerline of an instrument including guide <NUM>), similar to passage <NUM> of the exemplary embodiment of <FIG>.

According to the present invention, channels <NUM>-<NUM> impart a twisted path to actuation elements (not shown) that extend through channels <NUM>-<NUM> (such as according to the exemplary embodiments of International <CIT>, claiming priority <CIT>). For example, channels <NUM>-<NUM> are twisted in a manner similar to passages <NUM>-<NUM> of the exemplary embodiment of <FIG>, so that the actuation elements within channels <NUM>-<NUM> do not experience a substantial change in path length over the length of a wrist and are supported to minimize or prevent buckling of the actuation elements.

Actuation element guide <NUM> has a multi-piece construction comprising an inner piece <NUM> and an outer piece <NUM>, as shown in the exemplary embodiment of <FIG>. Inner pieces and outer pieces of the various exemplary embodiments described herein, such as inner piece <NUM> and outer piece <NUM>, may be first and second pieces of an actuation element guide. According to an exemplary embodiment, inner piece <NUM> is inserted within outer piece <NUM>, with surfaces of inner piece <NUM> and outer piece <NUM> cooperating to define one or more of channels <NUM>-<NUM>. As shown in <FIG>, which is an end view of <FIG>, outer piece <NUM> surrounds inner piece <NUM>, such as in a concentric manner.

One of the first and second pieces of an actuation element guide includes projections that extend along radial directions of the actuation element guide, according to an exemplary embodiment. The projections of the first or second piece may cooperate with a surface of the other of the first and second piece so that open regions between the projections define twisted channels of an actuation element guide. According to an exemplary embodiment, one of the first and second pieces of an actuation element guide includes projections arranged in a spoke-like configuration, extending either radially outwardly from an inner portion of the first or second piece or extending radially inwardly from an outer portion of the first or second piece. The projections cooperate with a surface of the other of the first and second piece so that open regions between the projections form at least part of the twisted channels of an actuation element guide.

As shown in the exemplary embodiment of <FIG> and <FIG>, which is a perspective view of outer piece <NUM> with inner piece <NUM> removed, outer piece <NUM> has an inner surface <NUM> that includes one or more projections <NUM> that project radially inward toward central channel <NUM> and longitudinal centerline <NUM>. According to an exemplary embodiment, projections <NUM> and open regions <NUM> between projections <NUM> define a spoke-like configuration of outer piece <NUM>. According to an exemplary embodiment, projections <NUM> of outer piece <NUM> twist about a longitudinal centerline <NUM> of actuation element guide <NUM>. Inner surface <NUM> of outer piece <NUM> also twist about longitudinal centerline <NUM> so that open regions <NUM> twist about longitudinal centerline <NUM>, as shown in the exemplary embodiment of <FIG> (with the twisted shape of one open region <NUM> being depicted in <FIG> with dashed lines for ease of viewing) , according to an exemplary embodiment. As a result, channels <NUM>-<NUM> (which are defined by inner surface <NUM> and open regions <NUM> of outer piece <NUM> and outer surface <NUM> of inner piece <NUM>), twist about longitudinal centerline <NUM> along an axial direction of guide <NUM>, as shown in the embodiment of <FIG> (with the twisted shape of only channel <NUM> being depicted with dashed lines for ease of viewing). A cross section of the twisting channels <NUM>-<NUM> taken at a location along the axial length of guide <NUM> (e.g., transverse to axis <NUM>) includes surface portions of both the inner piece <NUM> and the outer piece <NUM>, in particular, an interior surface portion of outer piece <NUM> and an exterior surface portion of inner piece <NUM>.

As shown in the embodiment of <FIG>, which is a perspective view of inner piece <NUM> of <FIG>, inner piece <NUM> is a modified tube with an outer wall <NUM> twisted about longitudinal centerline <NUM> of guide <NUM>. Outer wall <NUM> of inner piece <NUM> includes grooves <NUM> that longitudinally twist about longitudinal centerline <NUM> of guide <NUM>. Outer wall <NUM> of inner piece <NUM> is shaped to mate with corresponding inner ends <NUM> of projections <NUM> of outer piece <NUM>, as shown in the embodiment of <FIG>. Grooves <NUM> respectfully receive ends <NUM> of projections <NUM> of outer piece <NUM>. Raised portions <NUM> on either side of a groove <NUM> further conform the outer wall <NUM> to projections <NUM> so that cross-sectional shapes of channels <NUM>-<NUM>, as formed by inner surface <NUM> of outer piece <NUM> and outer wall <NUM> of inner piece <NUM>, are continuous or near-continuous circles, according to an exemplary embodiment. Thus, a space defined by inner wall of <NUM> of outer piece <NUM>, including a space between adjacent projections <NUM> of outer piece <NUM>, and defined by outer wall <NUM> of inner piece <NUM>, including a space defined by groove <NUM>, defines one of channels <NUM>-<NUM>. Although four twisted channels <NUM>-<NUM> are shown in the embodiment of <FIG>, more or fewer channels <NUM>-<NUM> may be formed in guide <NUM> by using more or fewer projections <NUM> and grooves <NUM>. Further, although projections <NUM> and grooves <NUM> are equally spaced around the longitudinal centerline <NUM> of guide <NUM>, projections <NUM> and grooves <NUM> may be spaced by different distances to provide channels of different sizes.

Another exemplary embodiment of an actuation element guide <NUM> that includes an inner piece <NUM> and an outer piece <NUM> is shown in <FIG>. Inner piece <NUM> and outer piece <NUM> may be referred to as first and second pieces. As shown in the exemplary embodiment of <FIG>, inner piece <NUM> is a tube structure and outer piece <NUM> surrounds inner piece <NUM>, such as in a concentric manner. For instance, inner piece <NUM> is a tube with a generally cylindrical cross-section having a generally uniform wall thickness. As a result, inner piece <NUM> may be manufactured using a straightforward extrusion technique, although other techniques also may be used. The lumen of the tube of inner piece <NUM> may form a non-twisting central channel <NUM>.

Outer piece <NUM> includes an inner surface <NUM> that includes projections <NUM> extending radially inward towards central channel <NUM>, according to an exemplary embodiment. Projections <NUM> and open regions <NUM> between projections <NUM> define a spoke-like structure for outer piece <NUM>, according to an exemplary embodiment. Projections <NUM> and open regions <NUM> may be twisted along an axial direction of guide <NUM> (e.g., into and out of the page of <FIG>, similar to the exemplary embodiment of <FIG>). According to an exemplary embodiment, outer piece <NUM> and inner piece <NUM> contact one another and define twisting channels <NUM>-<NUM> of guide <NUM>. According to an exemplary embodiment, inner ends <NUM> of projections <NUM> contact an outer wall <NUM> of inner piece <NUM>. Thus, open regions <NUM>, projections <NUM>, and outer wall <NUM> of inner piece <NUM> cooperate to define twisting channels <NUM>-<NUM> along an axial length of guide <NUM>, similar to the exemplary embodiment of <FIG>. As a result, inner piece <NUM> and outer piece <NUM> may define twisting channels <NUM>-<NUM> at a point (e.g., cross-section) along the axial length of guide <NUM>. According to an exemplary embodiment, a cross section of the twisting channels <NUM>-<NUM> taken at a location along the axial length of guide <NUM> (e.g., transverse to a longitudinal axis of actuation element guide <NUM>) includes surface portions of both the inner piece <NUM> and the outer piece <NUM>, in particular, an interior surface portion of outer piece <NUM> and an exterior surface portion of inner piece <NUM>.

As indicated in <FIG>, projections <NUM> may taper in a radial direction toward central channel <NUM> to provide a more circular cross-sectional shape for channels <NUM>-<NUM>, although projections <NUM> could have other shapes, such as a uniform thickness. Although four twisting channels <NUM>-<NUM> are depicted in the exemplary embodiment of <FIG>, other numbers of channels may be present, such as by using more or fewer projections. Further, although projections <NUM> may be equally spaced about inner piece <NUM> to provide equally sized channels <NUM>-<NUM>, projections may be unequally spaced so that the resulting channels vary in size.

Turning to <FIG>, an end view is shown of another exemplary embodiment of an actuation element guide <NUM>. According to an exemplary embodiment, actuation element guide <NUM> includes an inner piece <NUM> and an outer piece <NUM>, which may be referred to as first and second pieces. As shown in <FIG>, outer piece <NUM> has a simple tube structure that surrounds inner piece <NUM>. For instance, outer piece <NUM> is a tube with a generally cylindrical cross-section having a generally uniform wall thickness. As a result, outer piece <NUM> may be manufactured via a fairly straightforward extrusion technique, although other techniques may be used. Inner piece <NUM> forms a non-twisting central channel <NUM>, according to an exemplary embodiment.

According to an exemplary embodiment, outer surface <NUM> of inner piece <NUM> defines projections <NUM> that extend radially outward from central channel <NUM>. Outer surface <NUM> may also define open regions <NUM> between projections <NUM>, as shown in the exemplary embodiment of <FIG>. According to an exemplary embodiment, projections <NUM> and open regions <NUM> define a spoke-like configuration for inner piece <NUM>. Projections <NUM> and open regions <NUM> twist about central channel <NUM> along an axial direction of guide <NUM> (e.g., into and out of the page of <FIG>, similar to the exemplary embodiment of <FIG>), according to an exemplary embodiment. Thus, inner piece <NUM> and outer piece <NUM> may cooperate with one another, such as via ends <NUM> of projections <NUM> contacting an inner surface <NUM> of outer piece <NUM>, so that projection <NUM>, open regions <NUM>, and inner surface <NUM> define twisting channels <NUM>-<NUM> of guide <NUM>. As a result, inner piece <NUM> and outer piece <NUM> may define twisting channels <NUM>-<NUM> at a point (e.g., cross-section) along the axial length of guide <NUM>. According to an exemplary embodiment, a cross section of the twisting channels <NUM>-<NUM> taken at a location along the axial length of guide <NUM> (e.g., transverse to a longitudinal axis of actuation element guide <NUM>) includes surface portions of both the inner piece <NUM> and the outer piece <NUM>, in particular, an interior surface portion of outer piece <NUM> and an exterior surface portion of inner piece <NUM>.

Projections of an actuation element guide may vary in width along a radial direction of the guide. As shown in the exemplary embodiment of <FIG>, projections <NUM> increase in width in a radial direction from central channel <NUM> to outer piece <NUM>, such as to provide channels <NUM>-<NUM> with approximately circular cross-sections. Thus, projections <NUM> may have flared outer radial ends, as shown in the exemplary embodiment of <FIG>. However, projections <NUM> may have other shapes, such as a uniform width along the radial direction from central channel <NUM> to outer piece <NUM>. Spaces defined by adjacent projections <NUM> and inner wall <NUM> of outer piece <NUM> define twisting channels <NUM>-<NUM>. However, more or fewer channels may be defined in actuation element guide <NUM> by using more or fewer projections <NUM>. Further, although projections <NUM> may be equally spaced about central channel <NUM> to form equally sized channels <NUM>-<NUM>, as indicated in <FIG>, projections may instead vary in spacing to provide channels that vary in size.

<FIG> is an end view of an actuation element guide <NUM> that includes an inner piece <NUM> and an outer piece <NUM>, according to the present invention. Outer piece <NUM> surrounds inner piece <NUM>, similar to outer piece <NUM> and inner piece of the exemplary embodiment of <FIG>, except that outer piece <NUM> in the embodiment of <FIG> includes an inner wall <NUM> shaped to mate with outer radial ends <NUM> of projections <NUM> of the inner piece <NUM>.

Inner wall <NUM> of outer piece <NUM> includes recesses <NUM> to each receive outer radial ends <NUM> of projections <NUM>. Inner wall <NUM> further includes protrusions <NUM> located at lateral sides of recesses <NUM> that conform inner wall <NUM> to a shape of projections <NUM>. Corresponding recesses <NUM> are formed into inner wall <NUM> of outer piece <NUM> or are formed by protrusions <NUM> of inner wall <NUM>. Inner piece <NUM> further forms a non-twisting central channel <NUM>.

Inner piece <NUM> and outer piece <NUM> cooperate to define twisting channels, via projections <NUM>, open regions <NUM>, and inner wall <NUM> of outer piece <NUM> cooperating to define twisting channels <NUM>-<NUM>. As a result, inner piece <NUM> and outer piece <NUM> define twisting channels <NUM>-<NUM> at a point (e.g., cross-section) along the axial length of guide <NUM>. According to an exemplary embodiment, a cross section of the twisting channels <NUM>-<NUM> taken at a location along the axial length of guide <NUM> (e.g., transverse to a longitudinal axis of actuation element guide <NUM>) includes surface portions of both the inner piece <NUM> and the outer piece <NUM>, in particular, an interior surface portion of outer piece <NUM> and an exterior surface portion of inner piece <NUM>. Further, four twisting channels <NUM>-<NUM> are depicted in the exemplary embodiment of <FIG>, other numbers of channels may be present, such as by using more or fewer projections. In addition, although projections <NUM> may be equally spaced about inner piece <NUM> to provide equally sized channels <NUM>-<NUM>, projections may be unequally spaced so that the resulting channels vary in size.

As depicted in the exemplary embodiments of <FIG> and <FIG>, channels of an actuation element guide may have a generally circular cross-sectional shape. However, actuation element guides and channels of the various actuation element guide embodiments described herein may have other shapes. For instance, a cross-sectional shape of a guide or one or more channels of a guide may be modified to affect the bending strength of an actuation element guide. Turning to <FIG>, another exemplary embodiment of an actuation element guide <NUM> is shown. Actuation element guide <NUM> includes an inner piece <NUM> and an outer piece <NUM> (e.g., first and second pieces). Inner piece <NUM> defines a non-twisted central channel <NUM> and inner piece <NUM> and outer piece <NUM> cooperate to define twisted channels <NUM>-<NUM> according to any of the various exemplary embodiments described herein.

According to an exemplary embodiment, outer piece <NUM> may include one or more cutouts <NUM> to enhance the flexibility of actuation element guide <NUM>, as shown in the exemplary embodiment of <FIG>. Cutouts <NUM> may be located, for example, along a longitudinal length of actuation element guide <NUM> corresponding to locations experiencing bending (i.e., locations where enhanced flexibility of guide <NUM> may be advantageous), such as, for example, locations corresponding to a wrist of an instrument. According to an exemplary embodiment, cutouts <NUM> are disposed in guide <NUM> in locations corresponding to the greatest regions of bending of a wrist. Cutouts <NUM> may include other shapes than the generally rectangular cutout shape shown in the exemplary embodiment of <FIG>, such as, for example, square, oval, arcuate, or other shapes familiar to one of ordinary skill in the art.

Turning to <FIG>, an exemplary embodiment of an actuation element guide <NUM> is shown that includes an inner piece <NUM> and an outer piece <NUM> (e.g., first and second pieces). Inner piece <NUM> and outer piece <NUM> may be configured according to any of the various exemplary embodiments described herein and cooperate to define twisted channels <NUM>-<NUM>. According to an exemplary embodiment, a cross section of the twisting channels <NUM>-<NUM> taken at a location along the axial length of guide <NUM> (e.g., transverse to a longitudinal axis of actuation element guide <NUM>) includes surface portions of both the inner piece <NUM> and the outer piece <NUM>, in particular, an interior surface portion of outer piece <NUM> and an exterior surface portion of inner piece <NUM>. According to an exemplary embodiment, twisted channels <NUM>-<NUM> are twisted along the entire axial length of guide <NUM> (e.g., along axial direction indicated by arrows <NUM>). According to another exemplary embodiment, guide <NUM> includes a first section <NUM> in which channels <NUM>-<NUM> are twisted (as described in the various exemplary embodiments herein) and a second section <NUM> in which channels <NUM>-<NUM> are straight along the axial direction of guide <NUM>.

In the exemplary embodiment of <FIG>, at least one of channels <NUM>-<NUM> includes a port opening <NUM> that provides access to the at least one channel from an exterior of guide <NUM>. Channels <NUM>-<NUM> may be selected to include a port opening <NUM> based upon what extends through channels <NUM>-<NUM>. For example, actuation elements (not shown) extend through channels <NUM>, and <NUM> and conduits (not shown), such as electrical energy conduits, extend through channels <NUM> and <NUM>, which each include a port opening <NUM>. As result, the actuation elements are supported by channels <NUM> and <NUM> along the axial length of guide <NUM> and the conduits are supported by channels <NUM> and <NUM> in a distal portion of guide <NUM>, but the conduits may exit guide <NUM> via port openings <NUM> towards a proximal portion of guide <NUM>. As indicated in the exemplary embodiment of <FIG>, ports <NUM> may taper and decrease in depth along the axial direction <NUM>.

As described in the exemplary embodiments herein, an actuation element guide may include a plurality of pieces disposed generally concentrically relative to a central channel of the guide. Actuation element guides also may include a plurality of pieces along a longitudinal direction of the actuation element guide. Turning to <FIG>, an exemplary embodiment of an actuation element guide <NUM> is depicted that includes a first portion <NUM> and a second portion <NUM>, with first portion <NUM> and second portion <NUM> being aligned in series (e.g., end to end) along the longitudinal direction of guide <NUM>. Second portion <NUM> may be formed as a single piece, with straight, non-twisted channels. Because second portion <NUM> includes straight channels, second portion <NUM> may be manufactured via, for example, extrusion without twisting second portion <NUM>. As a result, manufacture of guide <NUM> can be facilitated. According to an exemplary embodiment, second portion <NUM> may be positioned in a shaft of an instrument (e.g., shaft <NUM> of <FIG>) so that second portion <NUM> does not substantially bend. As a result, straight channels may be provided in section portion <NUM>, which facilitates its manufacture.

First portion <NUM> may include twisted channels and be formed from multiple pieces, such as according to the various actuation element guide embodiments described herein. First portion <NUM> may be positioned within a wrist of an instrument (e.g., wrist <NUM> of <FIG>) so that first portion <NUM> is bent but actuation elements extending through the twisted channels of first portion <NUM> do not substantially change in path length. However, first portion <NUM> may be shorter in length along the proximal-distal direction of guide <NUM> than the various actuation element guide embodiments described herein, which facilitates manufacture of first portion <NUM> due to its short length over which its channels twist, in accordance with various exemplary embodiments. The channels of first portion <NUM> and second portion <NUM> align with one another where first portion <NUM> and second portion <NUM> interface so any actuation elements, conduits, or other instrument components extending through the channels extend through both first portion <NUM> and second portion <NUM>, according to an exemplary embodiment.

According to an exemplary embodiment, first portion <NUM> and second portion <NUM> are joined to one another, such as via, for example, welding, adhesive bonding, or another joining process familiar to one of ordinary skill in the art. According to another exemplary embodiment, first portion <NUM> and second portion <NUM> are not joined to one another but are connected via components extending through the respective channels of first portion <NUM> and second portion <NUM>, such as actuation elements. According to another embodiment, the positions of first portion <NUM> and second portion <NUM> are reversed relative to the proximal-distal direction, with first portion <NUM> located at a distal end of guide <NUM> and second portion <NUM> located at a proximal end of guide <NUM>. Further, although the exemplary embodiment of <FIG> has been described with first portion <NUM> and second portion <NUM> each being a single piece, first portion <NUM> and/or second portion <NUM> may be formed by a plurality of pieces joined together.

Pieces of actuation element guides of the various exemplary embodiments described herein may be manufactured via various techniques. According to an exemplary embodiment, inner and outer pieces of an actuation element guide are manufactured via, for example, molding, extrusion, and other techniques. Turning to <FIG>, a flow diagram for an exemplary method of manufacturing an actuation element guide is shown. The method <NUM> of <FIG> may be used to manufacture the actuation element guides of the various exemplary embodiments described herein. In step <NUM>, the pieces of the actuation element guide are manufactured as separate components. For example, inner and outer pieces of an actuation element guide are each manufactured via molding, extrusion, or other techniques. In step <NUM>, the pieces of the actuation element guide (e.g., the inner and outer pieces) are assembled together. In step <NUM>, the pieces of the actuation element guide are joined to one another such as, for example, via welding (e.g., laser welding, friction welding, or other types of welding processes), adhesive bonding, or other techniques. However, the various exemplary embodiments described herein are not limited to joining the pieces to one another because the pieces of an actuation element guide may be assembled together without joining (e.g., fixing) the pieces to one another.

One technique of manufacturing an actuation element guide piece is extrusion. Turning to <FIG>, an extrusion technique is shown for manufacturing an inner piece <NUM> of an actuation element guide, according to an exemplary embodiment. As shown in the exemplary embodiment of <FIG>, inner piece <NUM> is formed by forcing material through an extrusion die <NUM> along the direction indicated by arrow <NUM>. A twisted shape may be imparted to inner piece <NUM>, such as along the direction indicated by arrow <NUM>, by extruding inner piece <NUM> as a straight piece and then heat forming the extrusion in a subsequent step to impart the twist to inner piece <NUM>. Inner piece <NUM> may have the configuration of the exemplary embodiment of <FIG>, as indicated in <FIG>, or inner piece <NUM> may have the configuration of any of the various exemplary embodiments of actuation element guide inner pieces described herein. Further, although inner piece <NUM> has been described as being manufactured by an extrusion technique, inner piece <NUM> may be manufactured in another way, including via molding, for example.

Another exemplary technique for manufacturing a piece of an actuation element guide is molding. With reference to <FIG>, for example, a side cross-sectional view is shown of a molding process for manufacturing an outer piece <NUM> of an actuation element guide, according to an exemplary embodiment. Outer piece <NUM> may be formed by supplying molten material into mold <NUM>, which solidifies into shape desired for outer piece <NUM>, as defined by mold <NUM> and an insert <NUM> provided within mold <NUM>. Insert <NUM> may have a cross-sectional shape corresponding to inner surface <NUM> of the exemplary embodiment of <FIG>, or the inner surface of other outer pieces described in the various exemplary embodiments herein, with insert <NUM> being twisted along its longitudinal length to impart a twisted shape to the inner surface of outer piece <NUM>. Once molding is complete, insert <NUM> may be removed by twisting and pulling insert <NUM> from outer piece <NUM>, such as along the direction indicated by arrow <NUM> in <FIG>, and then outer piece <NUM> may be removed from mold <NUM>. Outer piece <NUM> may have the configuration of the exemplary embodiment of outer piece <NUM> <FIG>, or outer piece <NUM> may have the configuration of any of the various exemplary embodiments of actuation element guide outer pieces described herein. Further, although outer piece <NUM> has been described as being manufactured by a molding process, outer piece <NUM> may be manufactured by other processes, including extrusion, for example.

Actuation element guide pieces of the various exemplary embodiments described herein may be made from a flexible material. According to an exemplary embodiment, actuation element guide pieces are made of, for example, a flexible plastic, such as, for example, an elastomer, a polyether block amide (e.g., PEBAX®), fluorinated ethylene propylene (FEP), and other flexible plastics familiar to one of ordinary skill in the art. According to an exemplary embodiment, the inner and outer pieces of an actuation element guide are made of the same material. According to another exemplary embodiment, the inner and outer pieces of an actuation element guide are made of different materials. For example, an inner piece are made of a harder material than the outer piece, so as to provide higher wear resistance for the inner piece because the inner piece may experience more wear than the outer piece of an actuation element guide. Moreover, the inner piece is closer to the neutral axis of an actuation element guide, so using a higher hardness or higher strength material has less effect on the bending properties of an actuation element guide than using the same material for the outer piece. For example, an inner piece of an actuation element guide is made of material having a hardness of, for example, about <NUM> durometer Shore D. The outer piece of an actuation element guide is made of, for example, a material having a hardness ranging from, for example, about <NUM> durometer to about <NUM> durometer Shore D.

Once the inner and outer pieces have been manufactured, the inner and outer pieces may be joined together to form an actuation element guide. According to an exemplary embodiment, inner and outer pieces of an actuation element guide are joined together via laser welding. Turning to <FIG>, a laser welding process is depicted that illustrates joining an inner piece <NUM> and an outer piece <NUM> to form an actuation element guide <NUM>, according to an exemplary embodiment. Although inner piece <NUM> and outer piece <NUM> are configured according to the exemplary embodiment of <FIG>, the laser welding process of the exemplary embodiment of <FIG> may be applied to the various actuation element guide embodiments described herein.

As shown in <FIG>, a laser source <NUM> emits a laser beam <NUM> that is directed to an outer surface <NUM> of inner piece <NUM>. According to an exemplary embodiment, outer piece <NUM> may be substantially transparent or translucent and configured for transmission of laser beam <NUM> or a majority of laser beam <NUM> to pass through outer piece <NUM> until beam <NUM> reaches the outer surface <NUM> of inner piece <NUM>, which may be colored or otherwise configured to absorb the laser beam <NUM>. As a result, beam <NUM> may heat inner piece <NUM> at its outer surface <NUM>, which results in the inner piece <NUM> being welded to outer piece <NUM>.

A weld formed by laser welding may be a continuous weld along the longitudinal length of an actuation element guide or guide pieces may be welded together via discrete welds in a non-continuous manner. A weld between inner piece <NUM> and outer piece <NUM> may be a circumferential weld, such as by moving laser source <NUM> about outer piece <NUM> in at least one of the directions indicated by arrow <NUM> in <FIG> or by moving inner piece <NUM> and outer piece in at least one of the directions indicated by arrow <NUM>. According to another exemplary embodiment, beam <NUM> has a linear or planar shape (e.g., have a length along directions <NUM> in <FIG>) and pieces <NUM>, <NUM> and beam <NUM> are moved relative to one another, such as to move pieces <NUM>, <NUM> or beam <NUM> into or out of the page of <FIG>. According to another exemplary embodiment, beam <NUM> surrounds pieces <NUM>, <NUM> (e.g., beam <NUM> is an annular or circular beam) so that a relative rotation between beam <NUM> and pieces <NUM>, <NUM> along directions <NUM> may be minimized or avoided.

Techniques other than laser welding can be used to join pieces of an actuation element guide. According to an exemplary embodiment, pieces of an actuation element guide are joined, for example, via adhesive bonding, friction fitting, heat shrinking, or other joining techniques. For example, an outer piece may be heated to expand the outer piece, after which the outer piece may be fitted over an inner piece, and then allowed to cool so the outer piece may shrink and be force fit onto the inner piece. In another example, inner and outer pieces may be joined by making the outer piece out of heat shrinkable material, placing the outer piece about the inner piece, and heat shrinking the outer piece to assemble an actuation element guide. One consideration when joining inner and outer pieces to manufacture an actuation element guide is that the pieces remain joined in a substantially fixed position to one another during subsequent use, including movement of actuation elements relative to and against an actuation element guide and cleaning of an actuation element guide, which can include flushing fluid through an actuation element guide at a relatively high pressure. Further, although the exemplary embodiments of actuation element guides described herein may include a first piece and a second piece, such as an inner piece and an outer piece, the actuation element guides may include more than two pieces, such as, for example, three, four, or more pieces having surfaces that cooperate to define a twisting channel. In addition, the various pieces of the actuation element guides of the exemplary embodiments described herein may be joined to one another or may be placed in contact with one another without joining (e.g., fixing) the pieces to one another.

A process of joining first and second pieces to one another may result in an alteration of the geometry of at least one of the first and second pieces. As shown in the exemplary embodiment of <FIG>, an inner piece <NUM> may be inserted within an outer piece <NUM>, with inner piece <NUM> having a tube structure. Inner piece <NUM> and outer piece <NUM> may be subsequently joined to one another, such as via the various welding exemplary embodiments described herein. The joining process, such as heat from a welding process, may result in alteration of the geometry of at least one of inner piece <NUM> and outer piece <NUM>. For example, portions of inner piece <NUM> may melt and flow, resulting in alteration of the geometry of the inner piece. According to an exemplary embodiment, the joining process may result in the inner piece having the geometry of inner piece <NUM> depicted in the exemplary embodiment of <FIG>. For instance, portions of the inner piece may flow radial outward to form an outer surface <NUM> that includes raised portions <NUM> and grooves <NUM>, as shown in the exemplary embodiment of <FIG>.

The exemplary embodiments and methods described herein have been described as being utilized with surgical instruments for teleoperated surgical systems. However, the exemplary embodiments and methods described herein may be used with other surgical devices, such as laparoscopic instruments and other hand held instruments. Further, the exemplary embodiments and methods may be employed in other application that use remotely actuatable wrist or multiple joint structures, such as to remotely position an object attached to the wrist or joint structures. For instance, the exemplary embodiments described herein may be used in devices used for pipe inspection and other devices utilizing remote access via teleoperation or manual actuation.

By providing an actuation element guide comprising a plurality of pieces, manufacture of the actuation element guide may be facilitated, while providing an actuation element guide that supports actuation elements along a twisted path to substantially prevent a change in path length of the actuation elements.

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 and the 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 scope of the present teachings and following claims.

Claim 1:
An actuation element guide (<NUM>, <NUM>) for a surgical instrument (<NUM>, <NUM>), the actuation element guide (<NUM>, <NUM>) comprising:
an inner piece (<NUM>, <NUM>) comprising a first surface (<NUM>, <NUM>) defining a plurality of first projections (<NUM>, <NUM>) and a plurality of first recesses (<NUM>, <NUM>) between the first projections; and
an outer piece (<NUM>, <NUM>) comprising a second surface (<NUM>, <NUM>) defining a plurality of second projections (<NUM>, <NUM>) and a plurality of second recesses (<NUM>, <NUM>) between the second projections;
wherein the outer piece surrounds the inner piece and each of the first projections is within a respective one of the second recesses and each of the second projections is within a respective one of the first recesses,
wherein a plurality of guide channels (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, is defined in the first recesses or in the second recesses by the first and second surfaces,
wherein each of the guide channels (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is sized to receive an actuation element of a surgical instrument and defines a twisted path about a longitudinal centerline (<NUM>) of the actuation element guide (<NUM>, <NUM>);
wherein a cross-section of each of the guide channels, at a location along an axial length of the actuation element guide (<NUM>, <NUM>), is defined at least in part by a respective pair of the first projections and by a respective pair or the second projections.