Patent Description:
There is a pressing need in robotic or remotely controlled hand-operated surgery for small-diameter surgical tools with deflectable joints at various positions along the length of the tool, such as at the tip of the tool or at discrete locations along the length of the tool. These tools can be especially useful in procedures involving dexterity driven tasks, such as tissue dissection, resection, and suturing. Delivered through a natural orifice or percutaneously directly, through a delivery device such as an endoscope, or through the lumen of another small diameter surgical tool, these small-diameter surgical tools can be extremely useful in delicate and intricate surgical procedures, such as colorectal resection, pituitary tumor resection, neurosurgery, and intracardiac surgery. Many other surgical procedures can be aided by these tools.

<CIT> discloses a steerable catheter assembly comprising a nested tube structure, characterised in that one of the tubes is formed with a curvature at a distal portion. Rotating the tubes relative to each other defines the curvature of the catheter. Slots are cut in one or both tube walls to increase their flexibility in certain bend planes.

<CIT> discloses a bendable joint design consisting of a single tube with asymmetric slots cut out of the sidewalls. The joint is actuated by means of a tendon, which when tensioned, causes the tube to bend in the direction of the slots.

The invention is defined in appended claim <NUM>. Preferred embodiments of the invention are further defined in the dependent claims. An agonist-antagonist deflectable joint can be implemented in a small diameter surgical tool. The agonist-antagonist deflectable joint is an actuatable bendable structure that uses push-pull, agonist-antagonist action of a pair of nested tubes to actuate the joint. The tubes are designed to have non-central, offset neutral axes, and they are fixed together at locations distal to the deflectable joint, such as at their distal ends. Axial translations of the tubes relative to each other causes the push-pull, agonist-antagonist action between the tubes, which causes the deflectable joint to bend. In one implementation, a deflectable joint can be created in nested tubes by configuring radial portions of the tube sidewalls extending along the joint to have an axial region of reduced stiffness. As a result, axial agonist-antagonist motion between the tubes can cause bending of the deflectable joint.

According to this agonist-antagonist configuration, when the tubes exert axial push/pull forces on each other, which is realized at the connection between the tubes, e.g., at the distal end. As a result, for the tube upon which the pulling force is exerted, the section of the tube along the deflectable joint will bend in the direction of the axial region of reduced sidewall stiffness. Since the tubes are nested, the other tube will follow this bend. It is through this agonist-antagonist, push-pull action between the tubes that the deflectable joint can be actuated to bend.

One particular manner in which the tubes can be made to have a reduced stiffness along the bend joint is by selectively cutting asymmetric cutouts or notches into the profile of the tubes. The notches relocate the neutral bending planes of the tubes away from the center of the inner lumen of the nested tube structure. This relocation causes the tubes to bend in response to the agonist-antagonist relative axial movement of the tubes.

Because of this unique push-pull, agonist-antagonist configuration, the bendable structure does not present elastic stability issues, and offers a large range of motion and a low overall stiffness. Additionally, by varying the position of the neutral axes along the length of each tube (by configuring the position, direction, size, shape, etc. of the axial region of reduced sidewall stiffness), variable curvature actuation modes can be achieved. Pre-curving the nested tubes can additionally increase the workspace of a single segment. A single two-tube assembly can be used to create a deflectable structure with three degrees-of-freedom (DOF) Assemblies of three or more tubes can provide additional degrees-of-freedom. Additionally, multiple nested-tube surgical tool devices with deflectable portions can be deployed in a nested configuration to provide added dexterity.

According to one aspect, a surgical apparatus includes a nested tube structure comprising a first tube including a tubular side wall and a deflectable portion in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions. The apparatus also includes a second tube including a tubular side wall and a deflectable portion in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions. The apparatus also includes a connection between the first and second tubes at a location that is distal of the deflectable portions. The first tube is positioned so that the deflectable portions are at least partially aligned with each other axially, and so that the low stiffness portions face in radial directions that differ angularly from one another. The deflectable portions define a deflectable joint that is actuatable to bend in opposite directions. The apparatus further includes a control handle connected to the nested tube structure. The control handle includes a manual actuator mechanism for actuating the deflectable joint.

According to another aspect, alone or in combination with any other aspect, the control handle can be actuatable to apply an axial pulling force on the first tube relative to the second tube and to apply an axial pushing force on the first tube relative to the second tube. The application of an axial pulling force on the first tube relative to the second tube causes the first tube to pull on the second tube at the connection, which causes the deflectable portion of the second tube to deflect and bend in the direction of the low stiffness portion of the second tube. The application of an axial pushing force on the first tube relative to the first tube causes the second tube to apply tension to the first tube at the connection, the tension causing the deflectable portion of the first tube to deflect and bend in the direction of the low stiffness portion of the first tube.

According to another aspect, alone or in combination with any other aspect, the tubes can be configured so that the bending of the deflectable portion of the second tube in response to the pulling of the first tube exerts a bending force on the deflectable portion of the first tube, which causes the deflectable portion of the first tube to bend in the direction of the bend in the second tube.

According to another aspect, alone or in combination with any other aspect, the tubes can be configured so that the bending of the deflectable portion of the first tube in response to the pulling of the second tube exerts a bending force on the deflectable portion of the second tube, which causes the deflectable portion of the second tube to bend in the direction of the bend in the first tube.

According to another aspect, alone or in combination with any other aspect, the tubes can be configured so that the axial pulling force on the first tube relative to the second tube can be applied by one or both of: a) applying a pulling force on the first tube relative to the second tube, and b) by applying a pushing force on the second tube relative to the first tube. The tubes can also be configured so that the axial pushing force on the first tube relative to the second tube can be applied by one or both of: c) applying a pulling force on the second tube relative to the first tube, and d) by applying a pushing force on the first tube relative to the second tube.

According to another aspect, alone or in combination with any other aspect, the apparatus can also include an inner lumen that extends the length of the nested tube structure and is configured to receive a surgical instrument.

According to another aspect, alone or in combination with any other aspect, the surgical instrument can include an additional nested tube structure comprising a first tube and a second tube including deflectable portions that together define a deflectable joint actuatable to bend in opposite directions.

According to another aspect, alone or in combination with any other aspect, the surgical instrument can include at least one of curettes, grippers, surgical lasers, graspers, retractors, scissors, imaging tips, cauterizing tips, ablation tips, morcelators, knives/scalpels, cameras, irrigation ports, suction ports, needles, probes, and manipulators.

According to another aspect, alone or in combination with any other aspect, the first tube and the second tube can be nitinol tubes.

According to another aspect, alone or in combination with any other aspect, the first tube and the second tube can have one of a round and polygonal cross-section.

According to another aspect, alone or in combination with any other aspect, the apparatus can include a surgical instrument connected to a distal end of the nested tube structure.

According to another aspect, alone or in combination with any other aspect, surgical instrument can be at least one of curettes, grippers, surgical lasers, graspers, retractors, scissors, imaging tips, cauterizing tips, ablation tips, morcelators, knives/scalpels, cameras, irrigation ports, suction ports, needles, probes, and manipulators.

According to another aspect, alone or in combination with any other aspect, the actuator mechanism can include a lever that is pivotable to move the first tube axially relative to the second tube.

According to another aspect, alone or in combination with any other aspect, the actuator mechanism can include a gear and rack mechanism including a central gear rotatable manually and first and second rack gears engaged with the central gear and movable in opposite directions in response to rotation of the central gear. The rack gear can be connected to the second tube and the second rack gear can be connected to the first tube. Rotation of the central gear can move the first and second tubes axially in opposite directions relative to each other.

According to another aspect, alone or in combination with any other aspect, the actuator mechanism can include a central wheel supported on an axle and rotatable manually via a handle connected to the axle, wherein the second tube and the first tube are connected to an outer surface of the wheel at diametrically opposite positions, wherein rotation of the wheel via the handle moves the first and second tubes axially in opposite directions relative to each other.

According to another aspect, alone or in combination with any other aspect, the actuator mechanism can include a clutch that decouples the control handle from the nested tube structure so that the control handle can be rotated relative to the nested tube structure.

According to another aspect, alone or in combination with any other aspect, the nested tube structure can include an additional nested tube that further defines the deflectable joint. The additional tube can reinforce one of the first and second tubes. The additional tube can include a deflectable portion in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions of the side wall that at least partially align with the bendable portion of at least one of the first and second tubes.

According to another aspect, alone or in combination with any other aspect, the nested tube structure can further include an additional nested tube that further defines the deflectable joint. The additional tube can include a deflectable portion in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions of the side wall and a distal end connected to at least one of the first and second tubes.

According to another aspect, alone or in combination with any other aspect, the deflectable portion of the additional tube can be at least partially aligned with the deflectable portion of at least one of the first and second tubes. The deflectable portion of the additional tube can be actuatable to bend in the direction of the low stiffness portion of the additional tube.

According to another aspect, alone or in combination with any other aspect, the application of an axial pulling force on the additional tube relative to at least one of the second tubes can cause the deflectable portion of the additional tube to deflect and bend in the direction of the low stiffness portion of the additional tube.

According to another aspect, alone or in combination with any other aspect, the tubes can be configured such that the low stiffness portion of the additional tube is rotated relative to the low stiffness portions of the first and second tubes so that the bending plane of the deflectable portion of the additional tube bends is different than the bending planes of the deflectable portions of the first and second tubes.

According to another aspect, alone or in combination with any other aspect, the low stiffness portion of the first tube can be formed by portions removed from the tubular sidewall of the first tube to form a plurality of cutouts. The low stiffness portion of the second tube can be formed by portions removed from the tubular sidewall of the second tube to form a plurality of cutouts.

According to another aspect, alone or in combination with any other aspect, the cutouts of the first tube can face in at least two different directions and the cutouts of the second tube can face in at least two different directions. The deflectable joint when actuated can bend in at least two different directions that coincide with the directions of the cutouts.

According to another aspect, alone or in combination with any other aspect, the cutouts of the first tube and second tube can have depths that increase progressively from proximally to distally so that the bend of the deflectable portion becomes progressively sharp proximally to distally.

According to another aspect, alone or in combination with any other aspect, the cutouts of the first tube and second tube can have depths that decrease progressively from proximally to distally so that the bend of the deflectable portion becomes progressively sharp distally to proximally.

According to another aspect, alone or in combination with any other aspect, the radial positions of the cutouts of the first tube and second tube can rotate progressively from proximally to distally.

According to another aspect, alone or in combination with any other aspect, the apparatus can also include a bearing tip at the distal end of the nested tube structure. The bearing tip can include a first bearing component connected to the first tube and a second bearing component connected to the second tube. The first and second bearing components can be connected to each other and can have a bearing interface that promotes free rotation of the bearing components and the attached tubes while fixing their relative axial positions.

According to another aspect, alone or in combination with any other aspect, the apparatus can also include a pinned tip connection at the distal end of the nested tube structure. The pinned tip can include a slot in the second tube and a pin that is fixed to the first tube and projects radially outward through the slot. The pin and slot can interface each other to permit relative rotational movement of the first tube and the second tube while fixing their relative axial positions.

According to another aspect, alone or in combination with any other aspect, the first and second tubes each can also include a flexible transmission segment positioned proximally of the deflectable joint. The transmission segment of each tube can include a series of low stiffness regions of the first and second tubes.

According to another aspect, alone or in combination with any other aspect, the low stiffness regions of the first and second tubes can be formed by a plurality of slits that extend laterally into the tubes.

According to another aspect, alone or in combination with any other aspect, the slits can extend into the first and second tubes in pairs that extend toward each other into opposing sides of their respective tubes. Adjacent pairs of slits can be rotated ninety degrees about a longitudinal axis of the tubes.

According to another aspect, alone or in combination with any other aspect, the position of the transmission segment can be configured to coincide with the location of a bend or a bendable portion of a structure through which the nested tube structure is delivered.

Referring to <FIG>, according to an example configuration, a surgical system <NUM> includes a surgical apparatus or tool <NUM> having a small-diameter tubular form factor and including a bendable or deflectable joint <NUM>. As described herein, the deflectable joint <NUM> is configured to operate in an agonist-antagonist manner such that the joint can be actuated to deflect/bend in different, e.g., opposite, directions relative to a central axis <NUM> of the surgical tool <NUM>. In the example configuration of <FIG>, the deflectable joint <NUM> forms a distal tip of the surgical tool <NUM> and therefore can be referred to herein as a deflectable tip <NUM>. The position of the deflectable joint <NUM>, however, is not limited and could be located at any location along the length of the surgical tool <NUM>.

In the example configuration of <FIG>, the surgical tool <NUM> includes one or more small-diameter actuatable agonist-antagonist deflectable tube devices <NUM> including two or more tubes configured to translate and/or rotate relative to each other. The deflectable tube device <NUM> can be configured for robotic operation or manual operation. As shown in <FIG>, the surgical system <NUM> can include a drive system <NUM> for mechanically actuating the deflectable tube device <NUM>, and a control system <NUM> for controlling the operation of the drive system.

In a robotic implementation, the drive system <NUM> can include various actuation components, such as motors, solenoids, actuators, linkages, drive mechanisms, transmissions, etc. that supply the motive forces for operating the deflectable tube device <NUM>. In the robotic implementation, the control system <NUM> can include the input (operator control signals), processing, and signal generating components that generate the drive signals for controlling operation of the actuation components of the drive system <NUM>. In a manual implementation, the drive system <NUM> can be mechanism(s) that, through manual operation (i.e., by hand), manipulate the concentric tubes of the deflectable tube device <NUM>. As such, the control system <NUM> would be replaced by the user, such as a surgeon, manually operating the drive system <NUM>.

Each deflectable tube device <NUM> includes two or more tubes. In the example configuration of <FIG>, the deflectable tube device includes an outer tube <NUM> and an inner tube <NUM>. In this example configuration, an inner lumen <NUM> of the device <NUM> is defined by the lumen of the inner tube <NUM> and extends the length of the device through the deflectable tip <NUM>. The deflectable tip <NUM> is formed by distal portions of the outer and inner tubes <NUM>, <NUM>. The outer tube <NUM> and inner tube <NUM> are both constructed of a flexible material, such as nitinol tubing. Other flexible materials, such as plastics, could also be used to construct the tubes <NUM>, <NUM>. The outer tube <NUM> and inner tube <NUM> are configured to be movable both axially along and rotationally about the longitudinal central axis <NUM> of the surgical tool <NUM>.

In this description, the central axis <NUM> of the deflectable tube device <NUM> follows approximately the centers of the concentric tubes <NUM>, <NUM>. Since the tubes <NUM>, <NUM> are flexible/bendable, the central axis <NUM> is considered to follow whatever bend the concentric tubes follow. In this description, when reference is made to rotating the tubes <NUM>, <NUM> about the axis <NUM>, it is meant that rotation imparted to the tubes <NUM>, <NUM> at one location on the tubes, such as at the interface with the drive system <NUM>, causes the remainders of the tubes to rotate about the axis, regardless of whether the axis follows a curved or straight path.

In this description, when reference is made to translating the tubes <NUM>, <NUM> along the axis <NUM>, it is meant that translation is imparted to the tubes <NUM>, <NUM> at one location on the tubes, such as at the interface with the drive system <NUM>, and the remainders of the tubes translate along the axis, regardless of whether the axis follows a curved or straight path. Additionally, those skilled in the art will appreciate that the central axis may not follow both tubes exactly through a curve, as they may shift radially and/or laterally due to tolerances and spacing between the tubes. For this reason, the notion that the central axis <NUM> follows both tubes <NUM>, <NUM> can be considered to be somewhat generalized.

The deflectable portion <NUM> of the device <NUM> is illustrated in <FIG>. In this example configuration, the deflectable portion <NUM> is a distal tip of the device <NUM>. As shown in these figures, the deflectable joint <NUM> includes a deflectable portion <NUM> of the outer tube <NUM> and a deflectable portion <NUM> of the inner tube <NUM>. In the deflectable tip configuration of Figs. <NUM> and <NUM>, the deflectable portions <NUM>, <NUM> are distal tip portions of the tubes <NUM>, <NUM>.

The deflectable tip <NUM> has a non-actuated condition, shown in <FIG>, in which the deflectable tip is not bent and extends essentially or substantially along the tool axis <NUM>. The deflectable tip <NUM> is configured for bi-directional bending along a bending plane which coincides with the section plane of the sectional views of <FIG>. The tip <NUM> has a first actuated condition, shown in <FIG>, in which the tip is deflected in a first direction (see arrow A) to bend in the bending plane and assume a curved configuration. The tip <NUM> can be deflected in the first direction to an extreme, which is shown in dashed lines in <FIG>.

The deflectable tip <NUM> has a second actuated condition, shown in <FIG>, in which the tip is deflected in a second direction (see arrow B), opposite the first direction (arrow A), to bend in the bending plane and assume a curved configuration. The tip <NUM> can be deflected in the first direction to an extreme, which is shown in dashed lines in <FIG>. The deflectable tip <NUM> is selectively actuatable so that the degree of bending in the first and second directions can be set to any position between the extremes shown in dashed lines in <FIG>.

The deflectable portion <NUM> of the outer tube <NUM> has a configuration in which one side of the tube has a region of reduced stiffness relative to the other side of the tube in order to offset the neutral axis of the cross section away from the lumen centerline. This helps facilitate the actuatable deflection of the deflectable tip <NUM>. To achieve this purpose, in the example configurations illustrated herein, the outer tube <NUM> has a notched configuration. Referring to <FIG>, the reduced stiffness of the deflectable portion <NUM> is formed by a series of cutouts <NUM> where tube material (e.g., nitinol) is removed from the outer tube <NUM>. The cutouts <NUM> define bend joints <NUM>, which are the portions of the outer tube <NUM> that remain after the removal of the cutout material. The cutouts <NUM> also define bend sections <NUM>, which are tube segments that extend between the bend joints <NUM>. In the example configuration illustrated in <FIG>, the deflectable portion <NUM> of the outer tube <NUM> includes six cutouts <NUM> that define six bend joints <NUM> and six bend sections <NUM>. The deflectable portion <NUM> could include a greater number of cutouts <NUM> or fewer cutouts.

Similarly, the deflectable portion <NUM> of the inner tube <NUM> has a configuration in which one side of the tube has a region of reduced stiffness relative to the other side of the tube in order to offset the neutral axis of the cross section away from the lumen centerline. This helps facilitate the actuatable deflection of the deflectable tip <NUM>. To achieve this purpose, in the example configurations illustrated herein, the inner tube <NUM> has a notched configuration. Referring to <FIG>, the reduced stiffness of the deflectable portion <NUM> is formed by a series of cutouts <NUM> where tube material (e.g., nitinol) is removed from the inner tube <NUM>. The cutouts <NUM> define bend joints <NUM>, which are the portions of the outer tube <NUM> that remain after the removal of the cutout material. The cutouts <NUM> also define bend sections <NUM>, which are tube segments that extend between the bend joints <NUM>. In the example configuration illustrated in <FIG>, the deflectable portion <NUM> of the inner tube <NUM> includes six cutouts <NUM> that define six bend joints <NUM> and six bend sections <NUM>. The deflectable portion <NUM> could include a greater number of cutouts <NUM> or fewer cutouts.

In the example configuration of <FIG>, the design parameters for each of the deflectable portions <NUM>, <NUM> of the tubes <NUM>, <NUM> include the diameters of the tubes, the cut depth of the cutouts <NUM>, <NUM>, the axial length of the cutouts, the axial length of the bend sections <NUM>, <NUM>, the number of cutouts, and the shape or geometry of the cutouts. Through careful selection of these design parameters, the performance characteristics of the deflectable tip <NUM>, such as bending stiffness, arc length, bend radius, axial strength, and torsional stiffness can be selected.

Those skilled in the art will appreciate that the reduced stiffnesses of the tubes <NUM>, <NUM> to form the deflectable portions <NUM>, <NUM> can be achieved in manners other than through the implementation of the cutouts <NUM>, <NUM>. For example, in a plastic implementation, selective stiffening can be achieved through the use of different plastic materials to form the opposite sides of the tubes <NUM>, <NUM>. This can also be achieved through material variations within the cross section of the tubes <NUM>, <NUM>, or by varying the wall thicknesses of the tubes.

The notched configuration of the deflectable portions <NUM>, <NUM> permit the deflectable portions to bend. For the outer tube <NUM>, as the deflectable portion <NUM> bends, the bend joints <NUM> deflect and the bend sections <NUM> move and rotate/pivot. This movement is blocked when adjacent bend sections <NUM> engage each other or, in the case of the most proximally located bend section, engage the remainder of the outer tube <NUM>. The degree of movement that each bend section <NUM> is permitted to undergo is thus defined and limited by the aforementioned design parameters for the deflectable portion <NUM> of the outer tube <NUM>.

For the inner tube <NUM>, as the deflectable portion <NUM> bends, the bend joints <NUM> deflect and the bend sections <NUM> move and rotate/pivot. This movement is blocked when adjacent bend sections <NUM> engage each other or, in the case of the most proximally located bend section, engage the remainder of the inner tube <NUM>. The degree of movement that each bend section <NUM> is permitted to undergo is thus defined and limited by the aforementioned design parameters for the deflectable portion <NUM> of the inner tube <NUM>.

Referring to <FIG>, when assembled to form the deflectable tube device <NUM> and the deflectable tip <NUM>, the inner tube <NUM> and outer tube <NUM> are positioned so that their respective cutouts <NUM>, <NUM> are aligned with each other axially and are positioned facing in radially opposite (i.e., <NUM>-degree) directions. Arranged in these positions, at a distal tip <NUM> of the of the deflectable tube device <NUM>, a connection <NUM> connects the outer tube <NUM> to the inner tube <NUM>. This connection <NUM> can be mechanical (e.g., one or more pins or fasteners), adhesive (e.g., a glue, epoxy, or tape), a bonding (e.g., ultrasonic weld, heat bond), or a fixture, such as a cap.

The connection <NUM> locks the tips of the tubes <NUM>, <NUM> together, thus preventing translational movement of the interconnected tube ends relative to each other along the axis <NUM>. The connection <NUM> also can prevent rotational movement of the interconnected tube ends relative to each other about the axis <NUM>. In certain configurations, however (see, e.g., <FIG>), the connection <NUM> can permit relative rotation of the tubes <NUM>, <NUM> about the axis <NUM>. It is this connection <NUM> that facilitates actuation of the deflectable tip <NUM> without the use of cables, wires, or any other actuation member extending inside or outside the lumen <NUM> of the device <NUM>.

Advantageously, the bend joints <NUM> of the deflectable portion <NUM> of the outer tube <NUM> are aligned with each other linearly/axially and are interconnected by their co-adjacent bend sections <NUM>. Likewise, the bend joints <NUM> of the deflectable portion <NUM> of the inner tube <NUM> are aligned with each other linearly/axially and are interconnected by their co-adjacent bend sections <NUM>. In this manner, the interconnected bend joints <NUM> and bend sections <NUM> of the outer tube <NUM> form a spline <NUM> that extends continuously along the deflectable portion <NUM> and allows tension to be applied by the inner tube <NUM> along its entire length. Similarly, the interconnected bend joints <NUM> and bend sections <NUM> of the inner tube <NUM> form a spline <NUM> that extends continuously along the deflectable portion <NUM> and allows tension to be applied by the outer tube <NUM> along its entire length. Together, the splines <NUM>, <NUM> permit the tubes <NUM>, <NUM> to apply either tension or compression along their lengths, which allows for actuating the deflectable tip <NUM> in the first and second directions (see <FIG>) in response to relative axial movement of the tubes creating a push-pull on each other.

Actuation of the deflectable tip <NUM> is effectuated through relative axial movement of the tubes <NUM>, <NUM>, in an agonist-antagonist manner in which relative axial movements of the tubes act against each other to cause the tip to deflect. This agonist/antagonist action between the tubes is described herein as push/pull action of the tubes. For ease of explanation, the actuation is described herein in terms of pushing or pulling on the inner tube <NUM> to move the inner tube axially relative to the outer tube <NUM>. Those skilled in the art will appreciate that the same effect can be realized by pushing or pulling on the outer tube <NUM> to move the outer tube axially relative to the inner tube <NUM>. In fact, relative axial movement of the tubes <NUM>, <NUM> can also be realized by pushing on one tube while pulling on the other tube. All of these push/pull methods yield the same result. It is for these reasons that the agonist-antagonist operation of the deflectable tube device <NUM> and the deflectable tip <NUM> is described in terms of push/pull on the inner tube <NUM>, with the understanding that push/pull on the inner tube can be achieved by push/pull on one or both of the inner and outer tubes.

Referring to <FIG>, pulling the inner tube <NUM> relative to the outer tube <NUM> (as indicated generally by the downward facing arrow) actuates the deflectable tip <NUM> to bend in the first direction (arrow A) toward the illustrated bend condition. When this occurs, the inner tube <NUM>, through the spline <NUM>, pulls on or applies tension to the distal tip <NUM> at the connection <NUM> of the outer tube <NUM> and inner tube <NUM>. The inner tube <NUM> pulling on the outer tube <NUM> causes the bend joints <NUM> of the outer tube to deflect or bend in the first direction toward the region of reduced stiffness of the deflectable portion <NUM>, i.e., away from the spline <NUM> and toward the cutouts <NUM>. During this bending, the cutouts <NUM> provide space for the bend sections <NUM> to move toward each other. As a result, the outer tube <NUM> bends in the first direction.

The bending of the deflectable portion <NUM> of the outer tube <NUM> causes the deflectable portion <NUM> of the inner tube <NUM> to bend along with it. Since the bend joints <NUM> of the inner tube <NUM> are at least partially aligned with the bend joints <NUM> of the outer tube <NUM>, the deflectable portions <NUM>, <NUM> bend with each other with relatively little resistance. As a result, pulling on the inner tube <NUM> causes the deflectable tip <NUM> to bend in the first direction. The axial distance that the inner tube <NUM> is pulled relative to the outer tube <NUM> determines the degree to which the deflectable tip <NUM> bends in the first direction. With enough pull on the inner tube <NUM>, the deflectable tip <NUM> can be placed in the fully deflected first condition <NUM>'.

Conversely, referring to <FIG>, pushing the inner tube <NUM> relative to the outer tube <NUM> (as indicated generally by the upward facing arrow) actuates the deflectable tip <NUM> to bend in the second direction (arrow B) toward the illustrated bend condition. When this occurs, the inner tube <NUM> pushes on the distal tip <NUM> at the connection <NUM> of the tubes <NUM>, <NUM>. In effect, the outer tube <NUM>, through the spline <NUM>, pulls on the distal tip of the inner tube <NUM>. This pulling on the inner tube <NUM> causes the bend joints <NUM> of the inner tube to deflect or bend in the second direction toward the region of reduced stiffness of the deflectable portion <NUM>, i.e., away from the spline <NUM> and toward the cutouts <NUM>. During this bending, the cutouts <NUM> provide space for the bend sections <NUM> to move toward each other. As a result, the inner tube <NUM> bends in the second direction.

The bending of the deflectable portion <NUM> of the inner tube <NUM> causes the deflectable portion <NUM> of the outer tube <NUM> to bend along with it. Since the bend joints <NUM> of the outer tube <NUM> are at least partially aligned with the bend joints <NUM> of the inner tube <NUM>, the deflectable portions <NUM>, <NUM> bend with each other with relatively little resistance. As a result, pulling on the outer tube <NUM> causes the deflectable tip <NUM> to bend in the second direction. The axial distance that the outer tube <NUM> is pulled relative to the inner tube <NUM> determines the degree to which the deflectable tip <NUM> bends in the second direction. With enough pull on the outer tube <NUM>, the deflectable tip <NUM> can be placed in the fully deflected second condition <NUM>".

The inner and outer tubes of the deflectable tube device <NUM> can have cross-sectional configurations other than the round cross-section illustrated in <FIG>. Referring to <FIG>, the surgical system <NUM> can include a surgical tool <NUM> in the form of a deflectable tube device <NUM> that includes an inner tube <NUM> and an outer tube <NUM>, each of which has a hexagonal cross-sectional configuration. The deflectable tube device <NUM> thus has a hexagonal cross-sectional configuration. Alternative cross-sectional shapes, such as octagonal or other polygonal cross-sectional shapes, or elliptical cross-sectional shapes, can also be implemented.

In operation, the deflectable tube device <NUM>, particularly the deflectable tip <NUM>, can operate in a push/pull to actuate manner that is similar or identical to that described above in regard to the circular cross-section configuration of <FIG>. Any non-circular cross-sectional configuration of the device <NUM> can provide certain performance characteristics that may be desirable over those provided by a circular cross-section. For example, the hexagonal cross-section of the device <NUM> of <FIG> can have a higher torsional stiffness or bending resistance than a similarly dimensioned device with a circular cross-section, because the cross sections cannot rotate with respect to each other.

The surgical tool <NUM> can be configured to utilize the deflectable tube device <NUM> in a variety of manners. For example, as shown in <FIG>, the surgical tool <NUM> can utilize the deflectable tube device <NUM> as an actuatable sheath in which the device/tool can be delivered to a surgical site, e.g., via endoscope (straight or flexible), cannula (straight or flexible), or directly without using an introductory device. Once delivered, actuating the deflectable tip <NUM> in combination with gross rotational and axial positioning of the deflectable tube device <NUM> can position the distal end <NUM> in a precise location at the surgical site. Since the configuration of the distal tip <NUM> is such that actuator tendon wires are not required, the inner lumen <NUM> of the device <NUM> is left open and clear to deliver one or more surgical instruments, such as one or more additional deflectable tube devices, a deflectable tube device carrying a surgical tool, or one or more surgical tools carried by wire or other structures. Example surgical instruments include curettes, grippers, surgical lasers, graspers, retractors, scissors, imaging tips, cauterizing tips, ablation tips, morcelators, knives/scalpels, cameras, irrigation ports, suction ports, needles, probes, manipulators or any other surgical instrument.

In this configuration of the surgical tool <NUM>, the distal tip <NUM> of the deflectable tube device <NUM> is delivered to the surgical site. Then, the surgical instrument is navigated through the lumen <NUM> of the device <NUM> and delivered to the surgical site. The surgical instrument is then operated separately to perform the desired operation. The operation of the surgical instrument can, however, be aided through actuation of the deflectable tube device <NUM> in concert with the instrument.

As another example, as shown in <FIG>, the surgical tool <NUM> can itself carry an end effector or instrument <NUM> connected to the distal end <NUM> of the deflectable tube device <NUM> and operated either remotely or through manipulation via the deflectable tube device. The end effector <NUM> can be any surgical instrument for which delivery via the small diameter surgical tool <NUM> is desired. For example, the end effector <NUM> can be a curette, grippers, surgical lasers, graspers, retractors, scissors, imaging tips, cauterizing tips, ablation tips, morcelators, knives/scalpels, cameras, irrigation ports, suction ports, needles, probes, manipulators or any other suitable surgical instrument.

In this configuration of the surgical tool <NUM>, the deflectable tube device <NUM> can deliver the end effector <NUM> to a desired surgical location in a variety of manners. For example, the deflectable tube device <NUM> can deliver the end effector <NUM> via an endoscope (straight or flexible) a catheter (straight or flexible), or even directly without using an introductory device. In one particular implementation, the tubes <NUM>, <NUM> of the device <NUM> can form the innermost tubes of a deflectable tube robotic structure having at least one additional concentric outer tube. In this implementation, the deflectable tip <NUM> and end effector <NUM> can be delivered via this deflectable tube robotic structure, which itself can be delivered via an endoscope, catheter, or directly, as set forth above.

The end effector <NUM> is connected to the distal end <NUM> of the deflectable tube device <NUM> at the distal end of the deflectable tip <NUM>. The deflectable tip <NUM> can thus manipulate the end effector <NUM> through manipulation of the device <NUM> and deflection of the tip <NUM>. Advantageously, the deflectable tube device <NUM>, particularly the deflectable tip <NUM>, is configured so that actuation of the tip does not require the use of any cables, wires, or any other element that extends through the inner lumen <NUM> of the device. This leaves the lumen <NUM> open and available for any other purpose, such as providing an electrical, mechanical, or fluid connection with the end effector <NUM>, providing an irrigation or suction channel, facilitating the use of a camera, or a combination of these purposes.

The surgical tool <NUM> can implement the principles of the deflectable tube device <NUM> and its deflectable joint <NUM> configuration in a variety of manners. In its simplest form, the deflectable joint <NUM> can be implemented as a deflectable tip <NUM> of a deflectable tube device <NUM>, as shown and described in <FIG>. In this configuration, the device <NUM> has three degrees of freedom: gross translational movement of the device along the axis <NUM>, gross rotational movement of the device about the axis, and bi-directional bending of the deflectable tip <NUM>. As mentioned previously, the deflectable joint <NUM> can be located at any position along the length of the device <NUM>. The degrees of freedom, however, remain the same: translation, rotation, and bending.

The inner tube <NUM> and outer tube <NUM> of the deflectable tube device <NUM> can be constructed of a material that facilitates a pre-curvature of the tubes themselves or the deflectable joint <NUM>. For example, a shape memory alloy, such as a nickel-titanium ("nitinol") alloy, can be bent to a desired curved configuration and heated so that the alloy retains or "remembers" this curvature. This is shown in <FIG>.

In <FIG>, the deflectable tip <NUM> has a pre-curved configuration, with the unactuated condition illustrated in solid lines. The deflectable tip <NUM> is actuatable in the manner described for bi-directional movement from the pre-curved configuration. In the pre-curved configuration, actuation of the first direction can act to further curve the deflectable tip, as illustrated in dashed lines at <NUM>'. Actuation in the second direction can act to extend or straighten the curvature of the deflectable tip, as illustrated in dashed lines at <NUM>".

Advantageously, the pre-curvature of the deflectable tip <NUM> can permit the distal tip <NUM> to reach further in the bending plane in the first direction. This further reach, of course, comes at the cost of a lesser reach in the bending plane in the second direction. The pre-curvature shifts the workspace of the of the deflectable tube device <NUM>. It will therefore be appreciated that the workspace of the surgical tool <NUM> can be tailored to a specific workspace, anatomy, and procedure.

The curvature of the deflectable joint <NUM> at any point along the joint is influenced by characteristics of the cutouts <NUM>, <NUM>, such as their location, depth, and angular position. By varying the configurations of the cutouts <NUM>, <NUM>, the direction and magnitude of curvature in the bending plane at any point on the deflectable joint <NUM> can be dictated.

For example, cutouts with a constant depth and angular location, such as those illustrated in the configuration of <FIG> will assume a constant-curvature shape when the deflectable joint is actuated. As another example, Referring to <FIG>, the depth of the cutouts <NUM>, <NUM> can be configured to get gradually deeper toward the tip <NUM>. Because of this, when the deflectable tip <NUM> is actuated from the non-actuated condition (solid lines at <NUM>) to the actuated condition (dashed lines at <NUM>'), the curvature of the deflectable tip <NUM> increases toward the tip <NUM> of the device <NUM>. This can be useful for applications in which "tip-first" bending is desired.

As another example, the cutouts <NUM>, <NUM> can be rotated axially by <NUM> degrees at a predetermined positon along the length of the deflectable joint <NUM>. For example, as shown in <FIG>, a proximal half of the cutouts <NUM>, <NUM> can be positioned facing one direction and the other distal half of the cutouts can be facing in the opposite direction. Because of this, when the deflectable tip <NUM> is actuated from the non-actuated condition (solid lines at <NUM>) to the actuated condition (dashed lines at <NUM>'), the proximal and distal halves curve in opposite directions, generating an s-shape which maintains the orientation of the tip <NUM>. Thus, during actuation, the movement of the tip <NUM> can be purely translational, as illustrated at <NUM>'. In this manner, the tip <NUM> translates while maintaining its orientation, i.e., the axis <NUM>, <NUM>' at the tip positions <NUM>, <NUM>' are parallel. This design can, for example, be useful in decoupling tip rotation from tip translation so that manual or robotic control is simpler and more intuitive.

The cutouts <NUM>, <NUM> can also be configured to help provide specific shapes and motion of the deflectable tip <NUM>. Referring to <FIG>, the <NUM> degree rotated cutouts <NUM>, <NUM> can configured to permit a purely bending movement at the tip <NUM>. In this configuration, the proximal cutouts <NUM>, <NUM> can form a smaller portion (i.e., less than half) of the total number of cutouts, such as about <NUM>%. Because of this, when the deflectable tip <NUM> is actuated from the non-actuated condition (solid lines at <NUM>) to the actuated condition (dashed lines at <NUM>'), the proximal and distal portions curve in opposite directions. Because the proximal cutouts <NUM>, <NUM> form a disproportionally small percentage of the total number of cutouts, the distal portion can curve opposite the proximal portion to maintain the translational position of the tip <NUM>. As a result, during actuation, the tip <NUM> rotates in a manner such that the axis <NUM> at the tip rotates or pivots about a point, as illustrated generally at <NUM> and <NUM>'. Thus, during actuation, the movement of the tip <NUM> can be purely rotational, with the bending angle at the tip rotating as illustrated at <NUM>' while maintaining its lateral position. In this configuration, there is no lateral displacement within the bending plane at the tip <NUM>. As with the configuration of <FIG>, the configuration of <FIG> can also be useful in decoupling tip translation from rotation so that manual or robotic control is simpler and more intuitive.

In another example configuration, the cutouts <NUM>, <NUM> can be rotated about the axis <NUM> gradually along the length of the deflectable joint <NUM>. In this example configuration, the actuated shape of the deflectable joint <NUM> will be helical.

In another example configuration, the depths cutouts <NUM>, <NUM> can be configured to become gradually shallower toward the tip. In this configuration, the passive strength of the deflectable joint <NUM> with respect to external loads can be increased.

Additionally, the shape or profile of the cutouts <NUM>, <NUM> themselves can be configured to help address or alleviate structural issues that can arise regarding the deflectable joint <NUM>. For example, shapes such as circular, V-shaped, U-shaped, dogbone, parabolic, etc. can be used to help avoid stress concentrations, cracks, material fatigue, etc..

Advantageously, the cutouts <NUM>, <NUM> can be configured in any of the manners described in the preceding paragraphs in order to conform to a patient-specific or procedure-specific anatomy. Generally speaking, the cutouts <NUM>, <NUM> can be designed to conform to any class of desired shapes, such as those defined by patient anatomy or procedural requirements.

Advantageously, the modular design of the deflectable tube device <NUM>, providing an unobstructed lumen <NUM>, allows for multiple devices, each possessing a deflectable joint <NUM>, to be deployed. For example, as shown in <FIG>, an example configuration of a surgical tool 210a includes two deflectable tube devices 220a and 220b. Each of the devices 220a, 220b includes a deflectable joint 212a, 212b, respectively. In the example configuration of <FIG>, the deflectable joints 212a, 212b are deflectable tips. Either or both of the deflectable joints 212a, 212b could, however, be positioned at any desired location along the length of its corresponding deflectable tube device 220a, 220b.

As shown in <FIG>, the nested configuration of the surgical tool 210a allows for selectively bending the devices 220a, 220b. Since the inner device 220b is constructed of a flexible material (e.g. nitinol), it will follow the curve of the outer device 220a and extend from the distal end of the outer device. Since the outer device 220a is also constructed of a flexible material, the curvature of the deflectable joint 212a can be affected by the inner device 220b extending through it. The larger diameter of the outer device 220a can help minimize this affect. The configuration of the outer device 220a can also be designed/selected to help minimize this effect. For example, the outer device 220a can be constructed with tubes having a greater wall thickness or can be configured with a different cross-section, such as a hexagonal cross section.

Advantageously, the surgical tool 210a of <FIG> provides an increase in the degrees of freedom and the size/extent of the workspace in which the tool can operate. The surgical tool 210a of <FIG>, for example, provides six degrees of freedom - axial translation, rotation about the axis, and bending at the deflectable joint, for each of the deflectable tube devices 220a, 220b that make-up the tool 210a. Additional degrees of freedom can be added via further deflectable tube devices, with or without deflectable joints outside the two-device tool 210a of <FIG>. Additional degrees of freedom can also be realized through the deployment of a surgical instrument through the inner lumen 226b of the inner device 220b.

Referring to <FIG>, a surgical tool <NUM> can include a flexible transmission segment <NUM> on each tube <NUM>, <NUM> of the deflectable tube device <NUM>. The transmission segment <NUM> is configured to be flexible in bending (and symmetrically so), but still relatively stiff in the axial direction and in torsion. This can be done in a variety of manners, such as by forming the transmission segment <NUM> of a flexible material, such as plastic, in order to provide adequate bending properties, and then reinforcing the segment to provide the desired axial strength and torsional stiffness. Reinforcing a plastic transmission segment can be done, for example, by embedding reinforcing fibers in the structure of the transmission segment <NUM>, or by embedding members, such as wires, in a predetermined pattern, such as a helical or meshed pattern.

Another manner in which to configure the transmission segment <NUM> is illustrated in <FIG>. In this configuration, the transmission segment <NUM> includes a series of slits <NUM>, pairs of which extend toward each other into opposite sides of the tubes <NUM>, <NUM>. Each pair of slits <NUM> is rotated <NUM> degrees from the pairs of slits adjacent to it. As a result, the pairs of slits <NUM> are arranged in an alternating pattern in which they extend into the tubes <NUM>, <NUM> in directions that are perpendicular to each other, from pair to adjacent pair.

The transmission segments <NUM> define portions of the tubes <NUM>, <NUM> that are very flexible in bending the directions in which the slits <NUM> extend. Therefore, every other pair of slits <NUM> permits bending in one bending plane, while the slit pairs in between permit bending in another perpendicular bending. Together, the pairs of slits <NUM> permit bending of the transmission segment <NUM> in any direction. Advantageously, while the flexible transmission segments <NUM> reduces the bending stiffness of the tubes <NUM>, <NUM> to permit this bending, the torsional and axial stiffness of the transmission segments is maintained relatively high. To enhance the torsional and axial stiffness, in a plastic or polymer configuration of the device <NUM>, fiber reinforced materials could be used in the construction of the transmission segments <NUM>.

Those skilled in the art will appreciate that, much like the cutouts of the deflectable portions <NUM>, <NUM>, the flexure characteristics of the transmission segments <NUM> can be implemented in the tubes <NUM>, <NUM> in manners other than through the implementation of the slits <NUM>. For example, in a plastic implementation, the flexure characteristics of the transmission segments <NUM> can be implemented through the use of different plastic materials along the lengths of the tubes <NUM>, <NUM>. Flexure characteristics of the transmission segments <NUM> can also be implemented through material variations within the cross section of the tubes <NUM>, <NUM>, or by varying the wall thicknesses of the tubes.

In the assembled condition of the device <NUM>, the flexible transmission segments <NUM> of the inner and outer tubes <NUM>, <NUM> are aligned with each other axially along their respective lengths. Referring to <FIG>, the device <NUM> can be positioned in another device <NUM>, such as a pre-curved tube, a flexible endoscope, or a deflectable tip of another deflectable tube device, with the transmission segments coinciding with a curve in the device. Advantageously, the transmission segments <NUM> are configured to render the device <NUM> non-interacting with the device <NUM> in which it is positioned. By "non-interacting," it is meant that, due to the enhanced flexibility of the transmission segments <NUM>, actuation and rotation of the device <NUM> will not affect the position or motion of the outer device <NUM>. Similarly, due to the enhanced flexibility of the transmission segments <NUM>, the ability of the device <NUM> to actuate its deflectable tip <NUM> is unaffected by the curvature or motion of the outer device <NUM>.

Any motion of the deflectable tip <NUM> that would impart unwanted movement to the outer device <NUM> is absorbed or taken-up by the transmission segments <NUM>. Similarly, any motion of the outer device <NUM> that would impart unwanted movement to the device <NUM>, especially the deflectable tip <NUM>, is also absorbed or taken-up by the transmission segments <NUM>. It can therefore be seen that the transmission segments <NUM> can be positioned to de-couple the motion of the device <NUM> from structures in which it is positioned.

It can also be seen that, advantageously, the flexible transmission segments <NUM> also enables deployment of a deflectable tube device <NUM> along a curved path without affecting its ability to actuate its deflectable tip. This can be advantageous, for example, where the deflectable tube device is deployed through a curved delivery device, such as a flexible endoscope or a deflectable tube device. This can be especially advantageous in procedures such as minimally invasive procedures and Natural Orifice Transluminal Endoscopic Surgeries (NOTES).

The deflectable tube device <NUM> can include more than two concentric tubes. For instance, referring to <FIG>, an example configuration of the deflectable tube device <NUM> can include three tubes: an inner tube <NUM>, a middle tube <NUM>, and an outer tube <NUM>. The functions of the tubes <NUM>, <NUM>, <NUM> depends on the arrangement of the tubes themselves, i.e., the radial directions in which their respective deflectable portions face. To this end, the tubes <NUM>, <NUM>, <NUM> can be configured to enhance either the dexterity of the deflectable tube device <NUM> or to reinforce the device to increase stiffness and avoid tube buckling.

To enhance the dexterity of the deflectable tube device <NUM>, the tubes <NUM>, <NUM>, <NUM> can be rotated relative to each other so that their respective deflectable portions face along a bending plane in which bending is desired. Thus, in the configuration illustrated in <FIG>, the deflectable tube device can be configured to bend along three different bending planes, one for each tube in the structure. In this configuration, bending along one of the bending planes can be achieved by pulling simultaneously on the other two tubes. The pull forces applied by the tubes will cause the remaining tube to bend along the bending plane through or along which its deflectable portion faces.

The deflectable tube device <NUM> thus operates in a manner identical to the operation of the two-tube structures described herein, except that actuation is achieved by pulling on two tubes instead of one. To cause the deflectable tube device <NUM> to bend in the bending plane of the inner tube <NUM>, a pulling force is applied by the middle tube <NUM> and the outer tube <NUM>. Similarly, to cause the deflectable tube device <NUM> to bend in the bending plane of the middle tube <NUM>, a pulling force is applied by the inner tube <NUM> and the outer tube <NUM>. Finally, to cause the deflectable tube device <NUM> to bend in the bending plane of the outer tube <NUM>, a pulling force is applied by the inner tube <NUM> and the middle tube <NUM>.

To reinforce the device to increase stiffness and avoid tube buckling, two out of the three tubes <NUM>, <NUM>, <NUM> can be configured to bend in the same or similar bending plane. For example, as shown in the configuration illustrated in <FIG>, the outer tube <NUM> can be used in a redundant manner to enforce the bending imparted by middle tube <NUM>. The outer tube <NUM> is positioned so that its cutouts face in the same direction as the cutouts in the middle tube <NUM>. The tubes <NUM>, <NUM> together provide increased torsional stiffness and axial strength while at the same time providing actuatable bending in the same bending plane.

Referring to <FIG>, the deflectable tube device <NUM> can include a bearing tip <NUM> at the distal end <NUM> of the structure. The bearing tip <NUM> can both connect the tubes <NUM>, <NUM> so that relative push/pull movement between the tubes causes the deflectable joint <NUM> to bend as described above, and also so that the tubes can rotate freely relative to each other. As such, the bearing tip <NUM> includes an outer bearing component <NUM> fixed to the outer tube <NUM> and an inner bearing component <NUM> fixed to the inner tube <NUM>. The bearing components <NUM>, <NUM> have a bearing interface that promotes free rotation between the components and the attached tubes <NUM>, <NUM>, while fixing their relative axial positions.

Referring to <FIG>, the deflectable tube device <NUM> can include a pinned tip connection <NUM> at the distal end <NUM> of the structure. The pinned tip <NUM> can both connect the tubes <NUM>, <NUM> so that relative push/pull movement between the tubes causes the deflectable joint <NUM> to bend as described above, and also so that the tubes can rotate freely relative to each other. As such, the pinned tip <NUM> includes a slot <NUM> in the distal end of the outer tube <NUM> and one or more pins <NUM> fixed to the inner tube <NUM> and extending through the slot. The pin <NUM> can ride in the slot <NUM> when the tubes <NUM>, <NUM> are rotated relative to each other and blocks relative axial movement between the tubes. The pinned tip <NUM> thus promotes free rotation between the tubes <NUM>, <NUM>, while fixing their relative axial positions.

The rotational tip connections illustrated in <FIG> can also be beneficial in the embodiments of <FIG> where the deflectable tube device <NUM> includes tubes in excess of two. By rotating the tubes <NUM>, <NUM>, <NUM> to desired positions relative to each other, the bending planes of the respective tubes can be selected. Because of this, the bending directions of the tubes <NUM>, <NUM>, <NUM> can be selected. Advantageously, this can allow for selecting the multiple actuation directions of the deflectable tube device <NUM> and also selecting which of the tubes <NUM>, <NUM>, <NUM> reinforce each other torsionally and axially. Additionally, with a rotational tip connection, these purposes can be selected/configured in real time while the device <NUM> is used.

The deflectable tube device <NUM> implementing a deflectable joint <NUM> can implement robotic control, manual control, or a combination of robotic and manual control. Example configurations of manual actuators are illustrated in <FIG> and <FIG>.

In the configuration of <FIG>, a control handle <NUM> includes a housing <NUM> that supports a gear and rack mechanism <NUM>. The gear and rack mechanism <NUM> includes an actuator gear <NUM> that is rotatable manually by the user, for example, via a knob <NUM> positioned outside the housing <NUM>. As another example, the control handle could be configured to rotate the gear <NUM> through rotation of the handle itself. Rotation of the gear <NUM> imparts axial movement in two racks <NUM>, <NUM>, each of which is connected to one of the inner and outer tubes of the deflectable tube device <NUM>. In the illustrated configuration, the first rack <NUM> is connected to the outer tube <NUM> and the second rack <NUM> is connected to the inner tube <NUM>.

In operation, clockwise rotation (as viewed in <FIG>) of the gear <NUM> causes the first rack <NUM> and the outer tube <NUM> to move in a first direction, indicated generally by arrow A in <FIG>, and the second rack <NUM> and inner tube <NUM> to move in a second direction, opposite the first direction, indicated generally by arrow B. Counterclockwise rotation of the gear <NUM> causes the first rack <NUM> and the outer tube <NUM> to move in the second direction (arrow B), and the second rack <NUM> and inner tube <NUM> to move in the first direction (arrow A).

The user can rotate the device <NUM> simply by rotating the handle <NUM> and can insert/retract the device simply though push/pull movement of the handle. The user can actuate the deflectable joint <NUM> by rotating the actuator gear <NUM>, e.g., via a control knob <NUM>. Where the deflectable joint is a deflectable tip <NUM> carrying an end effector, the effector can be used to perform a surgical task through a combination of gross tool movement via handle <NUM> movement and joint actuation via the gear and rack mechanism <NUM>.

Advantageously, the gear and rack mechanism <NUM> imparts relative axial movement to both the inner tube <NUM> and the outer tube <NUM> simultaneously. This increases the motion scaling of the device <NUM>, i.e., the amount of tip <NUM> deflection in response to knob <NUM> turning. This motion scaling can be tailored by selecting the gearing of the actuator gear <NUM> and racks <NUM>, <NUM>. The gearing can also be configured to provide a mechanical advantage that allows the user to actuate the tip <NUM> with very little effort, thus allowing him/her to achieve delicate operation. In the configuration of <FIG>, an actuator handle <NUM> includes a rotatable wheel <NUM> to which the tubes <NUM>, <NUM> are connected, for example, via respective pins or other fasteners. The outer tube <NUM> is connected to the outer circumference of the wheel <NUM> at a first location on the wheel (shown in dashed lines in <FIG>). The inner tube <NUM> is connected to the outer circumference of the wheel <NUM> at a second location diametrically opposite the first location.

The wheel <NUM> rotates on a shaft <NUM>, which is supported on a housing <NUM> of the handle <NUM>. The shaft <NUM> extends outside the housing <NUM> where it is connected to an actuator handle <NUM>. Rotation of the actuator handle <NUM> therefore imparts rotation to the wheel <NUM> via the shaft <NUM>. In use, the operator can grasp the device handle <NUM> to manipulate the device <NUM> axially and rotationally. To actuate the deflectable tip <NUM>, the user rotates the actuator handle <NUM> to impart rotation to the wheel <NUM>.

Rotation of the wheel <NUM> imparts axial movement to the tubes <NUM>, <NUM>. In the illustrated configuration, clockwise rotation of the wheel <NUM> causes the inner tube <NUM> to move in a first direction, indicated generally by arrow A in <FIG>, and the outer tube <NUM> to move in a second direction, opposite the first direction, indicated generally by arrow B in <FIG>. Counterclockwise rotation of the wheel <NUM> causes the inner tube <NUM> to move in the second direction, and the outer tube <NUM> to move in the first direction.

Referring to <FIG>, in a manually operated configuration of the surgical system <NUM>, the surgical tool <NUM> can be connected to a control handle <NUM>. The control handle <NUM> includes a cover <NUM> that serves as a handle for the user to grasp in order to manipulate the surgical tool. While the cover <NUM> is illustrated as having a generally cylindrical configuration, alternative configurations, such as an ergonomically contoured configuration, could be implemented.

The control handle <NUM> facilitates gross manipulation of the surgical tool <NUM>, i.e., the deflectable tube device <NUM>, by grasping the cover <NUM> and moving the system <NUM> as a whole. In doing so, the user can rotate the device <NUM> about the axis <NUM> (see arrow A), translate the device along the axis (see arrow B), and can adjust the attitude of the device, i.e., adjust the position of the axis itself (see arrow C). Additionally, the cover <NUM> can be pivoted about an actuator axis <NUM> (see arrow D) in order to actuate the deflectable joint/tip <NUM>, which is described in detail below with respect to <FIG>.

Referring to <FIG>, the control handle <NUM> includes an actuator mechanism <NUM> including a frame <NUM> with a circular base <NUM> and a rectangular lever support <NUM>. The base <NUM> supports a circular race <NUM> in a manner such that the race can rotate relative to the base about the tool axis <NUM>. The race <NUM> includes gear teeth <NUM> that extend annularly around an inner surface of the race. The lever support <NUM> supports a pair of pawls <NUM> that are spring biased to engage the gear teeth <NUM> and lock the base <NUM> and race <NUM> to prevent their rotating relative to each other. The pawls <NUM> include actuator buttons <NUM> positioned radially opposite each other on the lever support <NUM> and can be actuated by pulling the buttons against the spring bias to disengage the pawls from the gear teeth <NUM> and permit relative rotation of the race <NUM> relative to the base <NUM>/frame <NUM>. In this manner, these components form a clutch <NUM> for engaging and disengaging the frame <NUM> from the race <NUM>.

The control handle <NUM> also includes an outer tool support <NUM> that is connected to the race <NUM> and is configured to receive the deflectable tube device <NUM> and to connect to the outer tube <NUM> of the device. The control handle <NUM> also includes a tool actuator <NUM> that includes a cylindrical sleeve <NUM> and an inner tool support <NUM> that extends into the outer tool support <NUM> and connects with the inner tube <NUM> of the device <NUM>. The inner tool support <NUM> is connected to the sleeve <NUM> in a manner such that the inner tool support can rotate relative to the sleeve about the axis <NUM>. The inner tool support <NUM>, having a square cross-section that mates with an inner surface of the outer tool support <NUM> so that the inner tool support rotates about the axis <NUM> in response to rotation of the outer tool support. The tool actuator <NUM> is actuatable to move axially relative to the frame <NUM> such that the inner tool support <NUM> can translate axially relative to the outer tool support <NUM>.

The control handle <NUM> also includes an actuator lever <NUM> that is connected to the frame <NUM> and extends from the rear of the handle, opposite the device <NUM>. The lever <NUM> is connected for pivotal movement about the actuator axis <NUM>. The lever <NUM> includes fastener receiving apertures <NUM> that correspond to apertures <NUM> in the cover <NUM> so that the cover can be connected to the lever. In use, pivotal movement of the lever <NUM> can be effectuated through pivotal movement of the cover <NUM>. To facilitate this, the cover <NUM> includes slots <NUM> that provide clearance for the frame <NUM> and also permit user access to the pawl buttons <NUM>. The lever <NUM> has a generally L-shaped configuration with the pivot axis extending through the intersection of its legs. The longer leg of the L-shaped lever <NUM> is connected to the cover <NUM>.

The control handle <NUM> also includes a linkage <NUM> that has a first end pivotally connected to the shorter leg of the L-shaped lever <NUM> and an opposite second end pivotally connected to the tool cylindrical sleeve <NUM> of the tool actuator <NUM>. Through this linkage <NUM>, rotational/pivoting actuation of the lever <NUM> effects linear translational movement of the tool actuator <NUM> along the axis <NUM>. Referring to <FIG>, in a neutral position of the lever <NUM>, the inner tool support <NUM> is positioned relative to the outer tool support <NUM> such that the deflectable tip <NUM> is maintained in an unactuated, i.e., straight configuration.

Pivoting the lever <NUM> downward to the position of <FIG> moves the tool actuator <NUM> to the right as viewed in the figures, which causes the inner tool support <NUM> to move to the right relative to the outer tool support <NUM>. This causes rightward movement of the inner tube <NUM> relative to the outer tube <NUM> of the device <NUM>, which actuates the deflectable tip <NUM> to bend upward as shown in <FIG>. Pivoting the lever <NUM> upward to the position of <FIG> moves the tool actuator <NUM> to the left as viewed in the figures, which causes the inner tool support <NUM> to move to the left relative to the outer tool support <NUM>. This causes leftward movement of the inner tube <NUM> relative to the outer tube <NUM> of the device <NUM>, which actuates the deflectable tip <NUM> to bend downward as shown in <FIG>.

Because, as described above, the cover <NUM> is configured to pivot with the lever <NUM>, the actuation movements shown and described in <FIG> can be performed by manipulating the cover. Thus, grasping the control handle <NUM> by the cover <NUM>, both gross movements of the surgical tool <NUM> and actuation movements of the deflectable tip <NUM> can be performed. Gross tool movements are performed by moving the entire control handle structure, while the actuation movement of the deflectable tip <NUM> are performed conveniently by pivoting the user's wrist to pivot the cover <NUM>/lever <NUM>.

Those skilled in the art will appreciate that gross movements of the surgical tool <NUM> can involve rotating the entire tool in order to adjust the bending plane of the deflectable tip <NUM>. As a result, this can compromise hand-space/camera-space correspondence and thus make it difficult for the operator to intuitively actuate the tool <NUM> while viewing the workspace via a camera. Additionally, rotating the entire tool also can position the handle such that the actuator axis <NUM> no longer coincides with permitting the user to actuate the cover <NUM>/lever <NUM> through bending wrist motion.

Advantageously, the clutch <NUM> is actuatable to disengage the frame <NUM> from the race <NUM>, which decouples the device <NUM> from the control handle <NUM> so that the rotational position of the handle can be adjusted without affecting the rotational position of the device. When the clutch <NUM> is disengaged, the race <NUM> and the outer tool support <NUM> are disengaged from the frame <NUM> and therefore do not rotate with the handle. Since rotation of the inner tool support <NUM> is tied to rotation of the outer tool support <NUM>, and since the sleeve <NUM> is configured to rotate relative to the inner tool support, the inner tool support and sleeve also do not rotate with the handle. Actuation of the clutch <NUM> therefore decouples the device <NUM> rotationally from the handle.

When the clutch <NUM> is engaged, the pawls <NUM> re-engage the gears <NUM> on the race <NUM>, thereby re-coupling the race and outer tool holder <NUM> to the frame <NUM>. The race <NUM> and outer tool holder <NUM> thus rotate about the tool axis <NUM> with the control handle <NUM>. Since the outer tool holder <NUM> rotates the inner tool holder <NUM>, the inner tool holder is also re-coupled and rotates along with the control handle <NUM>. Advantageously, since the sleeve <NUM> is rotatable relative to the inner tool holder <NUM>, the rotational position of the frame <NUM> does not affect the ability of the control handle <NUM> to actuate the deflectable tip <NUM> through actuation of the lever <NUM>, which moves the inner tube <NUM> relative to the outer tube <NUM> of the device <NUM>.

The clutch <NUM>, permitting rotation of the control handle <NUM> without affecting the rotational position of the device <NUM>, advantageously helps the operator maintain hand-space/camera-space correspondence, as well as a position that is comfortable and allows for device actuation in response to a preferred intuitive hand/wrist motion. This also allows the user to adjust the holding position to match the field of view of a camera that can be viewed in tandem with the device so that movements in the user's hand space corresponds to similar movements in the camera space.

Claim 1:
A surgical apparatus (<NUM>), comprising:
a nested tube structure (<NUM>) comprising a first tube (<NUM>) including a tubular side wall and a deflectable portion (<NUM>) in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions (<NUM>), a second tube (<NUM>) including a tubular side wall and a deflectable portion (<NUM>) in which a portion of the side wall is configured to have a stiffness that is lower than opposing portions (<NUM>);
wherein the first tube is positioned so that the deflectable portions (<NUM>, <NUM>) are at least partially aligned with each other axially, and so that the low stiffness portions (<NUM>, <NUM>) face in radial directions that differ angularly from one another;
wherein the deflectable portions define a deflectable joint (<NUM>) that is actuatable to bend in opposite directions; and
wherein the apparatus further comprises a control handle (<NUM>) connected to the nested tube structure, the control handle including a manual actuator mechanism (<NUM>) for actuating the deflectable joint;
characterised in that,
the nested tube structure further comprises a connection (<NUM>) between the first and second tubes (<NUM>, <NUM>) at a location that is distal of the deflectable portions (<NUM>).