Surgical cannulas and related methods

Embodiments disclosed herein are directed to surgical cannulas and methods relating thereto. In some embodiments, a method includes cutting one or more lines in a tubular member to form a tubular body and a hinge of a surgical cannula. In some embodiments, a surgical cannula includes a fiber brag grating (FBG) reflector mounted to a tendon for deflecting a distal tip of the surgical cannula. A controller is coupled to the FBG reflector and is configured to determine a tension in the tendon based on reflected light from the FBG reflector. In some embodiments, a surgical cannula includes a tubular body including a plurality of apertures extending therethrough.

Not applicable.

BACKGROUND

Surgical procedures may involve the insertion of a tubular member (which may generically be referred to herein as a “cannula”) into a body of a patient. The tubular member may be used to guide or deliver other surgical tools or implements, fluids, medications, sensors, etc. to a desired location within the patient's body. Some cannulas may be “steerable” in order to allow the physician to maneuver the cannula along or within a desired pathway in the body, and to place the distal end of the cannula at a desired location. In addition, some robotic surgical devices may make use of such steerable cannulas when performing surgical procedures.

BRIEF SUMMARY

Some embodiments disclosed herein are directed to a method of manufacturing a surgical cannula. In an embodiment, the method includes (a) providing an elongate tubular member, and (b) cutting one or more lines in the tubular member to form a tubular body and a hinge. The tubular body is pivotably coupled to the hinge. One of the tubular body and the hinge comprise a pin, and the other of the tubular body and the hinge comprise a socket, and (b) includes forming the pin within the socket by cutting the one or more lines.

Other embodiments disclosed herein are directed to a surgical cannula. In an embodiment, the surgical cannula includes a tubular body, a distal tip coupled to the tubular body, and a tendon coupled to the distal tip, wherein application of a tension to the tendon is configured to displace the distal tip. In addition the surgical cannula includes a fiber brag grating (FBG) reflector mounted to the tendon such that a tension in the tendon causes a strain on the FBG reflector. Further, the surgical cannula includes a controller coupled to the FBG reflector. The controller is configured to receive reflected light from the FBG filter and to determine the tension in the tendon based on the received reflected light.

In another embodiment, the surgical cannula includes a central axis, a tubular body, and a distal tip coupled to the tubular body such that the distal tip is configured to deflect relative to the tubular body. In addition, the surgical cannula includes a plurality of apertures extending through the tubular body. Each of the apertures includes a first end and a second end circumferentially spaced from the first end, a first curved surface at the first end, and a second curved surface at the second end. In addition, each of the apertures includes a first pair of straight edges extending from the first curved surface, and a second pair of straight edges extending from the second curved surface. A first edge of the first pair of straight edges intersects a first edge of the second pair of edges at a first point. A second edge of the first pair of straight edges intersects a second edge of the second pair of edges at a second point. The first pair of edges converge toward one another when moving from the first curved surface to the first and second points, and the second pair of edges converge toward one another when moving from the second curved surface toward the first and second points.

Embodiments described herein comprise a combination of features and characteristics intended to address various shortcomings associated with certain prior devices, systems, and methods. The foregoing has outlined rather broadly the features and technical characteristics of the disclosed embodiments in order that the detailed description that follows may be better understood. The various characteristics and features described above, as well as others, will be readily apparent to those skilled in the art upon reading the following detailed description, and by referring to the accompanying drawings. It should be appreciated that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes as the disclosed embodiments. It should also be realized that such equivalent constructions do not depart from the spirit and scope of the principles disclosed herein.

DETAILED DESCRIPTION

The following discussion is directed to various exemplary embodiments. However, one of ordinary skill in the art will understand that the examples disclosed herein have broad application, and that the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

The drawing figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . .” Also, the term “couple” or “couples” is intended to mean either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection of the two devices, or through an indirect connection that is established via other devices, components, nodes, and connections. In addition, as used herein, the terms “axial” and “axially” generally mean along or parallel to a given axis (e.g., central axis of a body or a port), while the terms “radial” and “radially” generally mean perpendicular to the given axis. For instance, an axial distance refers to a distance measured along or parallel to the axis, and a radial distance means a distance measured perpendicular to the axis. Further, when used herein (including in the claims), the words “about,” “generally,” “substantially,” “approximately,” and the like mean within a range of plus or minus 10%.

As previously described above, cannulas, such as steerable cannulas, may be used during a surgical procedure to introduce medication, tools, or other equipment into a body of a patient. During insertion of the cannula, it may be steered from the proximal end (e.g., by a physician and/or a surgical robot) to advance the tip of the cannula along a desired path within the patient's body. Such steering may be accomplished by selectively deforming or bending the cannula in a plurality of directions as the cannula is advanced into the body. In addition, the steering of the cannula is further facilitated by twisting or turning the cannula about its central axis, in concert with the selective deformation described above.

Given the relatively small size of steerable, surgical cannulas, it can be difficult (and therefore expensive) to manufacture the interlocking components that allow some or all of the above described deformations. Specifically, formation and subsequent assembly of the relatively small interlocking components or parts is particularly labor intensive and can lead to damage or weakening of the individual components. Also, some of the above described selective deformations of a surgical cannula may be accomplished by applying tension to one or more tendons extending axially along the cannula's. However, as the length of the cannula increases (e.g., to reach areas or locations within the body that are distally disposed from the access point along the patient's skin), the force or tension applied to the tendon for providing the desired deformation of the cannula tip may also increase. Thus, in some circumstances, the maximum allowable force or tension that may be borne by the tendon or even the cannula itself may be exceeded. Further, during a surgical procedure, it can be difficult to estimate or otherwise ascertain the reaction forces transferred to the cannula from the surrounding tissue.

Accordingly, some embodiments disclosed herein include surgical cannulas that include a plurality of patterned holes or apertures therein to enhance axial bending or deformation, while maintaining sufficient torsional rigidity to facilitate steering of the cannula during operations. In addition, some embodiments of the cannulas disclosed herein also include a deformable hinge comprising a plurality of axially adjacent pivotably coupled components that may be formed in situ from a solid tubular member so as to avoid the tedious and potentially damaging assembly process described above. Further, some embodiments disclosed herein include force sensing tendons for deflecting or deforming the tip of the cannula during operations that may allow the physician or operator (or robotic surgical device) to actively and accurately monitor the force or tension loads placed on the tendons and the cannula during operations.

Referring now toFIG.1, an embodiment of a surgical cannula10according to some embodiments is shown. Cannula10includes a central or longitudinal axis15(that may bend and flex along with cannula10as shown inFIG.1), a tubular body12, a hinge20, and a distal tip50. The distal tip50is disposed at a distal end of the cannula10. In addition, the hinge20is axially disposed between distal tip50and tubular body12.

Referring now toFIGS.1and2, tubular body12is an elongate, tubular member that includes a proximal end (not shown) and a distal end12aopposite proximal end along axis15. In some embodiment, tubular body12includes a cylindrical cross-section and includes a radially outermost surface13and a radially inner most surface17. In some embodiments, the radially outermost surface13and the radially inner most surface17are cylindrical surfaces; however, surfaces13,17may include other shapes (e.g., oval, polygonal, triangular, rectangular, etc.) in other embodiments. The radially inner most surface17defines a central, axially extending throughbore or lumen16that extends from proximal end (not shown) to distal end12a.

In addition, tubular body12includes a plurality of patterned holes or apertures14extending generally radially through the radially outermost surface13and the radially innermost surface17. Thus, apertures14extend into central throughbore16. As best shown inFIG.1, the apertures13are arranged in a repeating pattern that extends both circumferentially and axially with respect to axis15. In some embodiments, each of the apertures13have the same shape. For instance, reference is now generally made toFIGS.3-5which show embodiments of apertures14that may be disposed along tubular body12in some embodiments. Each of the embodiments of apertures13shown inFIGS.3-5are described in turn below. It should be noted that axis15is generally shown inFIGS.3-5so as to better show the relative orientation of the apertures depicted therein.

In some embodiments, some or all of the apertures extending through tubular body12(e.g., apertures14inFIG.1) may be shaped or formed as an elongated, rounded slot. For instance, reference is now made toFIG.3which shows an aperture100that may be formed in tubular body12(e.g., seeFIG.1). Aperture100includes a first end100aand second end100bcircumferentially separated from first end100aabout axis15. A first curved surface102is formed at first end100a, and a second curved surface104is formed at second end100b. In some embodiments (such as the embodiment ofFIG.3), curved surfaces102,104are generally circular in shape; however, other curvatures are contemplated (e.g., oval, elliptical, parabolic, hyperbolic, etc.). In addition, aperture100includes a pair of straight sides or edges106,108that extend circumferentially between curves surfaces102,104. Each of the sides106,108are axially separated from one another along axis15so as to define the opening of aperture100through surfaces13,17of tubular body12(see e.g.,FIG.1). In this embodiment, sides106,108each extend tangentially from the curved surfaces102,104at ends100a,100b, respectively. Aperture100may include a maximum length L100extending circumferentially between ends100a,100b, and a maximum width W100that extends axially between sides106,108. Aperture100is generally elongate such that length L100is greater than the width W100. Generally speaking, in some embodiments the length L100and width W100may range from a few micrometers to a few millimeters, depending on the size (e.g., diameter, thickness, length, etc.) of the tubular body12. In addition, in some embodiments, the apertures100may have an aspect ratio L100/W100that that is greater than 1.

Referring now toFIG.4, the apertures100are arranged along tubular body12in a plurality of axially spaced rows110. Each row110includes a plurality of apertures100uniformly-circumferentially spaced form one another about axis15. In addition, the apertures100of each row110are circumferentially misaligned or shifted from the apertures100in each immediately axially adjacent row110, so that apertures100are generally uniformly spaced about tubular body12.

Without being limited to this or any other theory, the arrangement, shape, and alignment of apertures100along body12generally increases the flexibility of tubular body102such that tubular body12may be generally flexed, bent, or otherwise deformed along axis15. However, because apertures100are generally elongate and extend circumferentially about axis15, tubular body12may still be substantially rigid in response to torsion about axis15(i.e., tubular body12generally resists torsional deformation while generally allowing bending or deflections of axis15). As a result, apertures impart a so-called auxetic behavior (or a negative Poisson's Ratio) to tubular body12.

Referring now toFIG.5, an aperture200is shown that may be formed on tubular body12(see e.g.,FIG.1) in some embodiments. In this embodiment, apertures200may have a so-called “dog bone” shape or profile. Aperture200includes a first end200aand second end200bcircumferentially separated from first end200aabout axis15. A first curved surface202is formed at first end200a, and a second curved surface204is formed at second end200b. In some embodiments (such as the embodiment ofFIG.3), curved surfaces102,104are generally elliptical in shape; however, other curvatures are contemplated (e.g., circular, parabolic, hyperbolic, etc.). In addition, aperture200includes a pair of axially spaced straight sides or edges206,308that extend circumferentially between curves surfaces202,204. Aperture200may include a maximum length L200extending circumferentially between ends200a,200b. In addition, aperture200has a first pair of maximum widths W202, W204extending axially across curved surfaces202,204, respectively, that are generally greater than a maximum width W206-208extending axially between sides206,208. Thus, the curved surfaces202,204extend axially outside of sides206,208such that aperture200has a so-called “dog bone” shape as previously described. As with aperture100, aperture200is generally elongate such that the length L200is greater than each of the widths W202, W204, W206-208. Generally speaking, in some embodiments the length L200and widths W202, W204, W206-208may range from a few micrometers to a few millimeters, depending on the size (e.g., diameter, thickness, length, etc.) of the tubular body12. In addition, in some embodiments, the apertures200may have an aspect ratio L200/W202or of L200/W204that is greater than 1.

Referring now toFIGS.4and5, in the same manner as described above for apertures100, the apertures200are arranged along tubular body12in a plurality of axially spaced rows (e.g., rows110inFIG.4). In addition, the apertures200have the same circumferential and axial spacing within the rows (e.g., rows110) that is previously described above with respect to the apertures100and generally shown inFIG.4. Thus, the description of the relative arrangement of apertures200within the axially spaced rows is not repeated herein in the interest of brevity.

Without being limited to this or any other theory, the arrangement, shape, and alignment of apertures200impart an auxetic behavior to tubular body12for substantially the same reasons discussed above with respect to aperture100. As a result, when tubular body102includes the dog-bone style apertures200, the tubular body12is configured to generally resist torsional deformation while also being generally configured to bend and flex along axis15.

Referring now toFIG.6, an aperture300is shown that may be formed on tubular body12(see e.g.,FIG.1) in some embodiments. In this embodiment, apertures300may have a so-called “rounded re-entrant honeycomb” shape or profile. Aperture300includes a first end300aand second end300bcircumferentially separated from first end300aabout axis15. A first curved surface302is formed at first end300a, and a second curved surface304is formed at second end300b. In some embodiments (such as the embodiment ofFIG.3), curved surfaces302,304are generally circular in shape; however, other curvatures are contemplated (e.g., oval, elliptical, parabolic, hyperbolic, etc.). In addition, aperture300includes a first pair of straight edges306a,308athat extend tangentially from curved surface302and a second pair of straight edges306b,308bthat extend tangentially from curved surface304. The first pair of straight edges306a,306bconverge toward one another along axis15as they extend circumferentially from first curved surface302, and the second pair of straight edges306b,308bconverge toward one another along axis15as they extend circumferentially from second curved surface304. The edges306a,306bmeet at a point or corner303, and the edges308a,308bmeet at a point or corner307. The corners303,307are generally circumferentially equidistant from ends300a,300b, and are axially spaced from one another along axis15.

Aperture300may include a maximum length L300extending circumferentially between ends300a,300b. In addition, aperture200has a first pair of maximum widths W302, W304extending axially across curved surfaces302,304, respectively, that are generally greater than a maximum width W306-308extending axially between corners303,307. Thus, the curved surfaces202,204extend axially outside of corners303,307, sides306a,308aextend linearly from points303,307to first curved surface, and sides306b,308bextend linearly from points303,307to second curved surface304. As a result, aperture300has a so-called “rounded re-entrant honeycomb” shape as previously described. As with aperture100, aperture300is generally elongate such that the length L300is greater than each of the widths W302, W304, W303-307. Generally speaking, in some embodiments the length L300and widths W302, W304, W303-307may range from a few micrometers to a few millimeters, depending on the size (e.g., diameter, thickness, length, etc.) of the tubular body12. In addition, in some embodiments, the apertures300may have an aspect ratio L300/W302or of L300/W304that ranges is greater than 1.

Referring now toFIGS.4and6, in the same manner as described above for apertures100, the apertures300are arranged along tubular body12in a plurality of axially spaced rows (e.g., rows110inFIG.4). In addition, the apertures300have the same circumferential and axial spacing within the rows (e.g., rows110) that is previously described above with respect to the apertures100and generally shown inFIG.4. Thus, the description of the relative arrangement of apertures300within the axially spaced rows is not repeated herein in the interest of brevity.

Without being limited to this or any other theory, the arrangement, shape, and alignment of apertures300impart an auxetic behavior to tubular body12for substantially the same reasons discussed above with respect to aperture100. As a result, when tubular body102includes the rounded re-entrant honeycomb style apertures300, the tubular body12is configured to generally resist torsional deformation while also being generally configured to bend and flex along axis15.

Referring again toFIG.1, the apertures14(or apertures100,200,300, etc.) may be formed, in some embodiments, via a laser machining process. In particular, during operations, a laser is directed onto radially outermost surface13of tubular member12to generate a high heat flux that melts and/or vaporizes the material to thereby form the desired aperture shape (e.g., apertures100,200,300, etc.). Any suitable laser may be used for this process, such as, for example a CO2laser or a neodymium yttrium aluminum garnet laser. In some embodiments, apertures14(e.g., or apertures100,200,300, etc.) may be formed by directing the laser along a radius of axis15(e.g., such that the laser points toward axis15during cutting operations); however, in other embodiments, the laser may be directed along a non-radial path (i.e., one that does not pass through axis15) during a laser cutting operation for tubular member12.

Tubular body12may comprise any suitable material for a surgical device. In some embodiment, tubular body12comprises a metal, such as, for example nickel-titanium (e.g., Nitinol). In some embodiments, tubular body12, hinge20, and distal tip50all comprise the same material.

Referring still toFIG.1, hinge20includes a plurality of segments that are pivotably coupled to one another along axis15so that allow hinge20to flex or bend in a plurality of different directions or planes. In particular, in some embodiments hinge20includes a plurality of first segments22and a second segment30all pivotably coupled to one another. It should be appreciated that in other embodiments, hinge20includes different numbers and arrangements of segments22,30than that described below for the embodiment ofFIG.1. For instance, in some embodiments, hinge20may include only first segments22(either one or a plurality thereof), only second segments30(either one or a plurality thereof), or a combination of first segments22and second segments30(again, either one or a plurality of either or both segments22,30).

Referring now toFIGS.7and8, each first segment includes a body24including a first end24a, a second end24bopposite first end24a, and a throughbore21extending axially (along axis15) between ends24a,24b. In some embodiments, body24is cylindrical in shape; however, other shapes are possible and contemplated for other embodiments (e.g., square, triangular, rectangular, polygonal, etc.).

A pair of pins26extend axially from second end24bof body24that radially oppose one another across axis15(i.e., pins26are disposed approximately 180° apart from one another about axis15). As best shown inFIG.7(which only depicts one of the pins26), pins26are generally circular in shape; however, other curved shapes for pins26may be used in other embodiments. In addition, second end24bof body may include a ramped or sloped surface27that extends from pins26at a non-zero angle θ relative to a radius of axis15. Without being limited to this or any other theory and as will be described in more detail below, during operations the clearance provided by ramped surfaces27may allow axially adjacent and pivotably coupled segments22,30to pivot within a desired range of motion.

Referring still toFIGS.7and8, a pair of apertures or sockets28extends into body24from first end24a. Sockets28are radially opposite one another about axis15, and in this embodiment, sockets28are substantially circumferentially aligned with pins26about axis15. Thus, in some embodiments, each socket28is disposed on the same circumferential side of body24as a corresponding one of the pins26. As with pins26, in some embodiments, sockets28are circular in shape; however, other curved shapes for pins26may be used in other embodiments. In some embodiments, sockets28are shaped to correspond with the shape of pins26, such that the pins26of one segment22may be received within the sockets28of an axially adjacent segment22within hinge20, which will be described in more detail below (see e.g.,FIG.1).

Referring now toFIGS.9and10, second segment30includes a body32including a first end32a, a second end32bopposite first end32a, and a throughbore31extending axially (along axis15) between ends32a,32b. In some embodiments, body32is cylindrical in shape; however, other shapes are possible and contemplated for other embodiments (e.g., square, triangular, rectangular, polygonal, etc.).

A first pair of sockets36extend axially into body32from second end32bthat radially oppose one another across axis15(i.e., sockets36are disposed approximately 180° apart from one another about axis15). As best shown inFIG.10(which only depicts one of the sockets36), sockets36are generally circular in shape; however, other curved shapes for sockets36may be used in other embodiments.

A second pair of sockets38extend axially into body32from first end32athat radially oppose one another across axis15(i.e., sockets38are disposed approximately 180° apart from one another about axis15). As best shown inFIG.9(which only depicts one of the sockets38), sockets38are generally circular in shape; however, other curved shaped for sockets36may be used in other embodiments. In addition, the second sockets38are circumferentially shifted from the positions of the first sockets36. In particular, in some embodiments, the second sockets38are shifted approximately 90° about axis form first sockets36.

Referring still toFIGS.9and10, second segment30also includes a slot34extending radially inward toward axis15. Slot34includes a first end34aand a second end34bcircumferentially spaced from first end34aabout axis15. In particular, in some embodiments ends34a,34bare radially opposite one another about axis15such that ends34a,34bare disposed approximately 180° from one another about axis15. However, other spacing values for ends34a,34bboth above and below 180° about axis15are contemplated.

Referring again toFIG.1, a connector19is mounted to distal end12aof tubular body12that includes a pair of pins26that are substantially the same as pins26on first segments22(previously described). One of the first segments22(which is designated inFIG.1and the text below as segment22A) is pivotably coupled to connector12such that pins26on connector19are pivotably received within sockets28of the first segment22A. Next, second segment30is pivotably coupled to segment22A such that the pins of segment22A are pivotably received within the first sockets36of second segment30. Pins26of connector19and segment22A are circumferentially aligned along axis15such that segments22A,30may pivot within a first longitudinal plane that includes axis15, relative to tubular body12(see e.g., the plane75extending along and including axis15that extends into the page in the view ofFIG.12). In addition, slot34on second segment30is positioned such that it is circumferentially centered with the pins26of segment22A and connector19.

Next, a second one of the first segments22(which is designated inFIG.1and the text below as segment22B) is pivotably coupled to second segment30such that pins26of segment22B are pivotably received within second sockets38of segment30. In addition, in the embodimentFIG.1, another of the first segments22(which is designated inFIG.1and the text below as segment22C) is pivotably coupled to the segment22B such that the pins26of segment22C are pivotably received within the sockets28of segment22B. Each the pins26of segment22are circumferentially aligned with the pins36of segment22C about axis15, such that segments22B,22C may pivot within a second longitudinal plane that includes axis15relative to second segment30(see e.g., the plane77extending along and including the axis15that extends along the page in the view ofFIG.11). The second longitudinal plane (within which the segments22B,22C may pivot as described above) is shifted approximately 90° about axis15from the first longitudinal plane (within which the segments22A and30may pivot as described above) (see e.g., planes75,77inFIGS.11and12) such that the first and second longitudinal planes are orthogonal to one another.

Referring still toFIG.1, the segments (e.g., segments22,30) of hinge20may be formed via a laser cutting or machining operation similar to that previously described above for forming apertures14(e.g., or apertures100,200,300, etc.). Thus, hinge20may be formed or manufactured by starting with a continuous hollow cylindrical member and then cutting, via a laser, the various channels and edges to form the sockets28,36,38, pins26, and slot24of segments22,30as previously described above. Accordingly, the formation of segments22,30and the assembly of segments22,30to form hinge20may be performed in a single manufacturing step (e.g., laser machining). As a result, the pins26of segments22,30may be formed within the corresponding sockets28,36,38as described above, such that insertion of pins26within sockets28,36,38is not necessary. In addition to being tedious, such insertion operations can cause damage (e.g., weakening, plastic deformation, etc.) to the relatively fragile pins26(and possible sockets28,36,38), and thus by avoiding these insertion operations, the structural integrity of the hinge20may be ensured. During the single step laser machining operation, the laser may be directed radially toward axis15and/or may be directed along a non-radial path as previously described above (e.g., with respect to the laser machining of apertures14,100,200,300, etc.).

Referring still toFIG.1, distal tip50includes a generally cylindrical body52including a first end52a, a second end52bopposite first end52a, and a throughbore51extending axially between ends51. A pair of pins26, each being the same as previously described above for segments22, extend axially from second end52b. As with the pins26on segments22, the pins26on distal tip50are radially opposite one another about axis15(i.e., pins26on distal tip50are disposed approximately 180° apart from one another about axis15). In addition, a bevel54is formed on body52that extends to first end52a. In this embodiment, bevel54is defined by a pair of helical surfaces55that meet or intersect at a sharp point or tip57at first end52a. In other embodiments, helical surfaces55may be replaced with substantially planar or flat surfaces, or any suitably shaped surfaces. The helical surfaces55forming bevel54also form an opening53into throughbore51at first end52a.

Further, body52of distal tip50also includes a slot56extending radially inward toward axis15. Slot56may be axially spaced between bevel54and second end52bof body52. Slot56includes a first end56aand a second end56bcircumferentially spaced from first end56aabout axis15. In particular, in some embodiments ends56a,56bare radially opposite one another about axis15such that ends56a,56bare disposed approximately 180° from one another about axis15. However, other spacing values for ends56a,56bboth above and below 180° about axis15are contemplated herein.

As shown inFIG.1, distal tip50is secured to a distal end of hinge20by inserting pins26on body52of distal tip50within the socket28of segment22C. The pins26on distal tip50are circumferentially aligned with the pins26of segments22B,22C, and thus, distal tip50may pivot in the second longitudinal plane along with the segments22B,22C as previously described above. In addition, slot56on body52is positioned such that it is circumferentially centered with the pins26of body52and segments22B,22C, and therefore is shifted approximately 90° from slot34on second body30.

Referring now toFIGS.1,2, and7-10, once surgical cannula10is fully constructed, the throughbore16of tubular body is in communication and aligned with the throughbore51of distal tip50along axis15via the throughbores21,31of segments22,30within hinge20. As a result, other surgical devices (e.g., guide wires, catheters, needles, etc.) may be inserted through surgical cannula10and out of opening53of distal tip50during operations. In addition, fluids or other substances (e.g., plasma, liquids, etc.) may be directed or channeled through cannula10(including tubular body12, hinge,20and distal tip50) and emitted from opening53during operations.

Referring now toFIGS.1,11, and12, during operations a plurality of tendons secured to surgical cannula10may be selectively tensioned to steer distal tip50as cannula10is advanced within the body of a patient. Specifically, in this embodiment a first tendon80extends through slot34in second segment30, and a second tendon82extends through slot56in distal tip50. Tendons80,82extend generally axially along tubular body12and are looped through the respective slots34,56. In addition, tendons80,82are bonded to surgical cannula10—with first tendon80being bonded to second segment30, and second tendon82being bonded to distal tip50. Tendons80,82may be bonded to cannula10with any suitable material or method. For instance, in this embodiment, tendons80,82are bonded to cannula with an adhesive84(e.g., an alkoxy-ethyl adhesive). Thus, each tendon80,82has a pair of sides or legs that extend axially along tubular body12. Specifically, first tendon80has a pair of legs80′,80″ that extend along radially opposite sides of tubular body12(see e.g.,FIG.12), and second tendon82has a pair of legs82′,82″ that extend along radially opposite sides of tubular body12(see e.g.,FIG.11). In this embodiment, each leg80′,80″,82′,82″ is individually bonded to cannula10with adhesive84(with legs80′,80″ each bonded to second segment30and legs82′,82″ bonded to distal tip50). Because slots34,56are shifted approximately 90° from one another about axis15as previously described above, legs80′,80″ of tendon80are also shifted approximately 90° from legs82′,82″ of tendon82. During operations, legs80′,80″ are selectively tensioned (e.g., pulled) to move or deflect distal tip50within first longitudinal plane75shown inFIG.12, and legs82′,82″ are selectively tensioned (e.g., pulled) to move or deflect distal tip50within second longitudinal plane77shown inFIG.11.

Referring briefly toFIG.13, in some embodiments, a protective sheathing or covering85is disposed about tubular body12and possibly also some or all of hinge20that includes a plurality of axially extending throughbores or channels81that receive legs80′,80″,82′,82″ of tendons80,82therethrough. Without being limited to this or any other theory, channels81are configured to protect legs80′,80″,82′,82″ during a surgical operation so as to ensure that tendons80′,80″,82′,82″ are not obstructed from axial movement and are separated from bodily fluids, tissue, etc.

In some embodiments, tendons80,82are not looped through slots34,56. For example, reference is now made toFIGS.14and15which show legs80′,80″ of tendon80and legs82′,82″ of tendons82separated from one another and individually bonded to surgical cannula10with adhesive84in the same manner as described above. Accordingly, in the embodiment ofFIGS.14and15, legs80′,80″,82′,82″ each form individual tendons routed along surgical cannula10, and operations with cannula10are the same as previously described with respect to the embodiment ofFIGS.11and12, and thus, they are not repeated again in the interest of brevity. Accordingly, selective tensioning of legs80′,80″ (ot tendons80′,80″) causes deflection of distal tip50within longitudinal plane75, and selective tensioning of legs82′,82″ (or tendons82′,82″) causes deflection of distal tip50within longitudinal plane77in the same manner as described above.

In some embodiments, the tendons of surgical cannula10(e.g., tendons80,82) may be partially or totally routed within central throughbore16of tubular body12. In particular, in the schematic example shown inFIG.16, legs80′,80″ are bonded to an external surface of hinge20via adhesive84as previously described above, and then are routed through holes or ports86in hinge20(e.g., holes86may extend through any one or more of the segments22,30) such that legs80′,80″ may be routed through throughbore16of tubular body12back toward the proximal end of cannula10. While note specifically shown, it should be appreciated that legs82′,82″ of tendons82(see e.g.,FIGS.11and12) may extend through similar holes86in distal tip50and/or hinge20and routed through throughbore16of tubular body12in the same manner as shown for legs80′,80″. Without being limited to this or any other theory, routing the tendons80,82through throughbore16may reduce the outer width of cannula10and may also protect tendons80,82from damage caused by abrasion between tendons80,82and tissue or other objects during operations. In addition, in some embodiments, tendons (e.g., tendons80,82) may be routed both externally and internally through tubular body12(e.g., one or more of the legs80′,80″,82′,82″ may be routed through throughbore16, and the remaining legs may be routed outside of throughbore16).

Tendons80,82may comprise any suitable material that may transfer sufficient tensile loads to deflect distal tip50and hinge20during operations. In some embodiment, tendons80,82may comprise a metal, a polymer, a composite, etc. In some embodiments, tendons may comprise poly-paraphenylene terephthalamide (e.g., Kevlar®). In some embodiments, tendons80,82may comprise fiber optic lines or cables.

Referring now toFIG.17, in some embodiments, the tendons80,82may be “sensorized” so that the force or tension applied to tendons80,82and also surgical cannula10may be actively measured during operations. For instance, a physician may wish to monitor the force loads transferred to cannula10during a surgical operation so as to ascertain the resistance being imparted to cannula10(e.g., at distal tip50) by the surrounding tissue. In addition, in some circumstances, it may be beneficial to monitor the magnitude of tension applied to the tendons80,82during steering operations so as to avoid over tensioning (and thereby damning) tendons80,82.

In the example ofFIG.17, only tendon82is shown so as to simplify the figure; however, it should be appreciated that the same technique described below may be applied to tendon80in substantially the same manner. In this embodiment, a fiber brag grating (FBG) reflector91is bonded to each leg82′,82″ with an adhesive90, such as, for example, an alkoxy-ethyl adhesive, and a fiber optic line92is coupled to and routed from each reflector91to a controller94. In some embodiments, FBG reflectors91may comprise a polarization maintaining FBG (PM-FBG), such as PM-FBG reflectors manufactured by Draw Tower Grating technology. In some embodiments, the PM-FBG reflectors91may include reinforcing wires or fibers (e.g., metal, polymer, etc.) such has fibers comprising titanium, poly-paraphenylene terephthalamide, etc. Each fiber optic line92may be routed alongside legs82′,82″, and thus fiber optic lines92may be extended within throughbore16, within channels81inFIG.13, etc. In some embodiments, fiber optic lines92may be bundled with legs82′,82″. Legs82′,82″ are each coupled to a corresponding actuator87,89, respectively, that are configured to apply a selective tension load during operations. While any suitable actuator may be used for actuators87,89, in this embodiment, actuators87,89comprise rotary actuators.

Controller94may comprise any suitable device or assembly which is capable of receiving an electrical, optical, or mechanical signal and transmitting various signals to other devices. In particular, as shown inFIG.17, in this example, controller94includes a processor95and a memory96, and interrogator97, and a receiver98.

The processor95(e.g., microprocessor, central processing unit, or collection of such processor devices, etc.) executes machine-readable instructions (e.g., non-transitory machine readable medium) provided on memory96, and upon executing the machine-readable instructions on memory96provides the controller94with all of the functionality described herein. The memory96may comprise volatile storage (e.g., random access memory), non-volatile storage (e.g., flash storage, read only memory, etc.), or combinations of both volatile and non-volatile storage. Data consumed or produced by the machine-readable instructions can also be stored on memory96.

Interrogator97may comprise any suitable device to emitting light signals that are transmitted, via fiber optic lines92, to filters91. For instance, interrogator97may comprise a tunable laser interrogator, similar to those available from FAZ Technologies, located in Dublin Ireland. Receiver98may comprise any suitable device for receiving, characterizing, and analyzing light waves reflected back from filter91via fiber optic lines92. Thus, receiver98may comprise appropriate light sensors for sensing the characteristics of the reflected light from reflectors91during operations. In some embodiments, receiver98is incorporated within interrogator97. In addition, in some embodiments, controller94may be a standalone unit that includes processor95, memory96, interrogator97, and receiver98, or may comprise a plurality of different units or members (e.g., one unit to house processor95and memory96and a separate unit to house interrogator87and receiver98) that are coupled to one another.

During operations, tension is selectively applied to legs82′,82″ of tendon82via actuators87,89to deflect distal tip50of surgical cannula10in a desired direction. Specifically, if tension is applied to leg82′ via actuator87, distal tip50is deflected in a first direction88shown inFIG.17, and if tension is applied to leg82″ via actuator89, distal tip50is deflected in a second direction83shown inFIG.17. As tension is applied to legs82′,82″, the tension is transferred to filters91via adhesive90. Accordingly, tension applied to legs82′,82″ causes a strain in reflectors91via adhesive90. In addition, during these operations, interrogator97may emit light signals that are directed to filters91via fiber optic lines92, and these light signals are then reflected back to controller94(particularly to receiver98) by reflectors91. Generally speaking, when a strain is applied to filters91(e.g., a strain resulting from the tension in legs82′,82″), the reflected light signals may have an altered wavelength response that is characteristic of the strain experienced by the filter91. As a result, machine readable instructions stored on member96and carried out by processor95may analyze the reflected light signals received by receiver98and calculate a strain experienced by filter91and ultimately to tension applied to legs82′,82″ at filter91. Thus, controller94may actively monitor the strain placed across filter91and thus also the force or tension applied to legs82′,82″ of tendon82during operations.

Without being limited to this or any other theory, because the tension in legs82′,82″ is measured, via reflector91, at a point relatively close to distal tip50(e.g., at the location of adhesive90), friction generated by engagement of legs82′,82″ and other objects or components between distal tip50and the proximal end of surgical cannula10is not measured by controller94. Therefore, the force or tension measurements taken by controller94for tendon82may be free of any noise generated by friction applied along legs82′,82″ such that the accuracy of these force or tension measurements may be increased.

Referring still toFIG.17, in some embodiments tendon82(seeFIGS.11and12) may comprise fiber optic lines (e.g., fiber optic lines92). Thus, in these embodiments, legs82′,82″ are coupled to both actuators87,89and controller94(particularly interrogator97and receiver98). During operation, tension is applied to legs82′,82″ via actuators87,89, respectively, as previously described. In addition, light signals are also simultaneously passed through legs82′,82″ and reflectors91to facilitate the tension measurements previously described above.

While embodiments of surgical cannula10discussed above have included a hinge20having a plurality of first segments22and a second segment30, in other embodiments, the hinge20may include a fewer number of components. For instance, referring now toFIG.18, another embodiment of surgical cannula400is shown. Surgical cannula400is substantially the same as surgical cannula10shown inFIG.1, and thus, components of surgical cannula400that are shared with cannula10are identified with the same reference numerals, and the discussion below will focus on the features of cannula400that are different form cannula10.

In particular, surgical cannula400includes tubular body12, distal tip50, and a hinge420. Hinge420does not include the first segments22(e.g., segments22A,22B,22C inFIG.1) and instead only includes second segment30, which is the same as previously described above. As shown inFIG.18, pins26of connector19on tubular body12are pivotably disposed within first sockets36of segment30, and pins26of distal tip50are pivotably disposed within second sockets38of segment30. Thus, during operations, distal tip50may be pivoted within a first longitudinal plane due to relative pivoting between segment30and connector19, and may be pivoted within a second longitudinal plane, that is orthogonal to the first longitudinal plane, due to relative pivoting between distal tip50and segment30. Tendons (e.g., such as tendons80,82, previously described) may be coupled to surgical cannula400to as to deform hinge420and deflect distal tip50in substantially the same manner as previously described above. Accordingly, a detailed description of these operations is omitted in the interests of brevity.

As is described above for surgical cannula10, the components of surgical cannula400may be formed in-situ by a laser cutting operation. Thus, surgical cannula400may be manufactured by starting with a hollow, elongate cylindrical member and cutting the various lines and apertures with an appropriate cutting tool (e.g., a laser cutting tool as described above) to form the connected distal tip50, hinge420, and tubular body12.

Referring now toFIG.19, another embodiment of a surgical cannula500is shown. Surgical cannula500is substantially the same as surgical cannula10shown inFIG.1, and thus, components of surgical cannula500that are shared with cannula10are identified with the same reference numerals, and the discussion below will focus on the features of cannula500that are different form cannula10.

In particular, surgical cannula500includes a central axis505tubular body12, distal tip50, and a hinge520. Hinge520includes a plurality of circumferential slits or grooves522that are configured to provide flexibility to hinge520in a plurality of different planes and directions. In this embodiment, grooves522extend circumferentially less than 180° about axis505. In addition, grooves522are arranged in a plurality of axially adjacent rows524such that each row524includes a pair of grooves522disposed radially opposite one another across axis505. In addition, the grooves522of each row524are circumferentially shifted compared to the orientation of the grooves522of the (or each) immediately axially adjacent row524. Thus, the circumferential ends of each groove522are misaligned from each immediately axially adjacent groove522along hinge520. It should be appreciated that the arrangement, spacing, and sizing of grooves522may be altered in other embodiments. For instance, in some embodiments, each groove522is disposed on a radially opposite side of hinge520from the (or each) immediately axially adjacent groove.

During operations, the grooves522provide flexibility to hinge520along a plurality of directions and planes. Tendons (e.g., such as tendons80,82, previously described) may be coupled to surgical cannula500to as to deform hinge520and deflect distal tip50in substantially the same manner as previously described above. Accordingly, a detailed description of these operations is omitted in the interests of brevity.

As is described above for surgical cannula10, the components of surgical cannula500may be formed in-situ by a laser cutting operation. Thus, surgical cannula500may be manufactured by starting with a hollow, elongate cylindrical member and cutting the various lines and apertures with an appropriate cutting tool (e.g., a laser cutting tool as described above) to form the connected distal tip50, hinge520, and tubular body12.

Some embodiments disclosed herein relate to a surgical tools or instruments that include or incorporate embodiments of the steerable surgical cannulas (e.g., surgical cannulas10,400,500, etc.) previously described above. For instance, reference is now made toFIGS.20and21, which show a surgical instrument600. In this embodiment surgical instrument600may be used during an endoscopic procedure. In particular, in this embodiment, surgical instrument may be particularly useful for an endoscopic surgical procedure within a patient's ear.

Surgical instrument600includes a central or longitudinal axis605and an outer sheath602including a plurality of flexure joints604and a tool window601. A camera603is mounted within sheath602that is configured to capture images or video through an open distal end602aof sheath602during an operation. Camera603may include a light source (not shown) coupled thereto or integrated therewith (not shown) to enhance the images captured thereby. One or more conductors607are coupled to camera603and are routed back through protective sheath602to a proximal end (not shown) of surgical instrument600. Conductors607may comprise any conductive member or path configured to transmit power, electrical, light, or other signals between camera603and an associated controlling device.

A surgical cannula610is retractably disposed within protective sheath602. Surgical cannula610may comprise any of the previously described surgical cannulas (e.g., cannulas10,400,500, etc.) or components thereof. Thus, components of surgical cannula610that are shared with component of the previously disclosed surgical cannulas10,400,500are identified with the same reference numerals. In this embodiment, surgical cannula610includes tubular body12(which may or may not include apertures14as previously described), a hinge620, and a distal tip650. In this embodiment, hinge620includes grooves622that are similar to the grooves522described above for surgical cannula500. In addition, distal tip50comprises a pair of surgical forceps for grasping tissue, or other objects or devices during a surgical procedure. Surgical cannula610is retractably inserted within a tubular jacket or sheath614which is further disposed within protective sheath602.

A tendon608, which may be similar to tendons80,82previously described above, is secured to protective sheath602and is routed back along sheath602toward its proximal end (not shown). During operations, tension may be applied to tendon608(e.g., directly by an operator or through an actuator, etc.) so as to deflect distal end602aof sheath602, thereby allowing surgical cannula610to extend axially from tubular jacket614and through tool window601such that a surgical procedure (or portion thereof) may be performed with distal tip650. During these operations, camera603may capture images of the distal tip650within a field of view606, so that the physician may monitor the progress of the surgical procedure.

In addition, during the above described operations, distal tip650of cannula610may be deflected and steered by selectively applying tension to tendons mounted thereto (not shown—see e.g., tendons80,82inFIGS.11,12,14,15, etc.) in the same manner as described above. Thus, a detailed description of these operations with respect to surgical cannula610is omitted herein in the interest of brevity.

Referring now toFIG.22, another surgical instrument700is shown. In this embodiment, like surgical instrument600, surgical instrument700may also be particularly useful for an endoscopic surgical procedure within a patient's ear.

Surgical instrument may include a central axis705, an outer tube704, a split tube702concentrically disposed within outer tube704, a tool channel714concentrically disposed within split tube702, and a surgical cannula710retractably disposed within tool channel714.

Surgical cannula710may comprise any of the previously described surgical cannulas (e.g., cannulas10,400,500,610, etc.) or components thereof. Thus, any of the components of surgical cannula710that are shared with components of the previously disclosed surgical cannulas10,400,500,610are identified with the same reference numerals. In this embodiment, surgical cannula710includes tubular body12(which may or may not include apertures14as previously described), a hinge720, and a distal tip750. Hinge720is substantially the same as hinge20shown inFIG.1, and thus includes segments22A,22B,22C, and30, the relative arrangement thereof being the same as previously described above for hinge20. In addition, distal tip750includes a pair of pins26that are pivotably disposed within the socket28of segment22C in the same manner as described above for distal tip50. Further, like distal tip650, in this embodiment distal tip750comprises a pair of surgical forceps.

During operations, split tube702, tool channel614, and surgical cannula710may all be retracted axially within outer tube702(e.g., such as when surgical instrument700is being inserted within the body of the patient). When desired, split tube702, tool channel614, and surgical cannula710may be axially projected from outer tub704such that split tube702opens to thereby expose tool channel714. Thereafter, surgical cannula710may be projected from tool channel714such that a surgical procedure (or portion thereof) may be performed with distal tip750. During these operations, cameras603(which are the same as camera603described above for surgical instrument600) may capture images of the distal tip750, so that the physician may monitor the progress of the surgical procedure. Cameras603are mounted within split tube702and are moved radially outward form central axis705when split tube702opens to expose tool channel714and surgical cannula710during operations.

In addition, during the above described operations, distal tip750of cannula710may be deflected and steered by selectively applying tension to tendons mounted thereto (not shown—see e.g., tendons80,82inFIGS.11,12,14,15, etc.) in the same manner as described above. Thus, a detailed description of these operations with respect to surgical cannula710is omitted herein in the interest of brevity.

Embodiments disclosed herein have included various improvements to a surgical cannula (e.g., a steerable surgical cannula). For instance, some embodiments disclosed herein have included surgical cannulas (e.g., surgical cannulas10,400,500,610,710, etc.) that include a plurality of patterned holes or apertures (e.g., apertures14,100,200,300, etc.) therein to enhance axial bending or deformation, while maintaining sufficient torsional rigidity to facilitate steering of the cannula during operations. In addition, some embodiments of the cannulas disclosed herein have include a deformable hinge that may be formed in situ from a solid tubular member so as to avoid the tedious and potentially damaging assembly process described above (e.g., hinges20,420,520,620,720, etc.). Further, some embodiments disclosed herein have included force sensing tendons (e.g., tendons80,82, etc.) for deflecting or deforming the tip of the cannula during operations that may allow the physician or operator (or robotic surgical device) to actively and accurately monitor the force or tension loads placed on the tendons during operations. Thus, through use of the embodiments disclosed herein, surgical operations utilizing a steerable cannula (e.g., such as surgical procedures carried out by a robotic surgical device) may be enhanced and improved.