Patent Description:
Medical practitioners have found it useful to use surgical robotic manipulators to assist in the performance of surgical procedures. An example of an end effector for a surgical robotic manipulator is disclosed in <CIT>. There is a need in the art to continuously improve such end effectors.

Document <CIT> is directed to a surgical instrument with a rotary cutting member and an adaptor. An angled adaptor may be fixedly interconnected with a tube. The angled adaptor includes a housing having a proximal housing alignable with a motor and a distal housing extending at an angle from the proximal housing. A motor coupling end of the proximal housing includes an internal cavity adapted to matingly receive the distal portion of the motor. The cavity includes flats configured to engage a double D section of the distal portion of the motor upon rotation to thereby lock the angled adaptor to the motor. Extending within cavity is a drive shaft having a power coupling end that includes an internal alignment bore and adjacent external drive portion. Opposite power coupling end, the drive shaft includes a power transfer gear coupled through an angle to a power transfer gear of a power shaft. Rotary force applied to the external drive portion may be transferred through gears and to the power shaft. Further, a tool coupling collet assembly may be actuated by movement of a section to lockingly hold a cutting tool within tube such that the rotary force of the motor may be transferred through angled adaptor to the cutting tool.

Exemplary embodiments are disclosed by dependent claims <NUM>-<NUM>.

The present disclosure provides a surgical tool assembly for use with an energy applicator to contact tissue of a patient at a surgical site, the energy applicator having a shaft extending along an axis between a proximal end and a distal end, the shaft having an axial-force receiving surface, as defined in claim <NUM>. The tool assembly comprises a support structure to support the energy applicator, an axial connector assembly arranged to engage and releasably lock the energy applicator to the support structure in a locked state, a drive system coupled to the support structure to rotatably drive the shaft of the energy applicator about the axis, a collet assembly cooperating with the axial connector assembly to apply a force to the axial-force receiving surface of the energy applicator when the axial connector assembly engages and releasably locks the energy applicator to the support structure in the locked state, and a reference surface. The force includes an axial component directing the energy applicator proximally into continuous contact with the reference surface in the locked state.

The present disclosure also provides a tool comprising an energy applicator including a shaft extending along an axis between a proximal end and a distal end and the tool assembly, as defined in claim <NUM>.

Other features and advantages of the present disclosure will be readily appreciated, as the same becomes better understood, after reading the subsequent description taken in conjunction with the accompanying drawings.

Certain of the Figures set forth above may have portions of the end effector removed for purposes of illustration.

Referring now to the Figures, wherein like numerals indicate like or corresponding parts throughout the several views, a system <NUM> for manipulating an anatomy of a patient <NUM> are shown throughout. As shown in <FIG>, the system <NUM> is a robotic surgical cutting system for cutting away material from the anatomy of the patient <NUM>, such as bone or soft tissue. In <FIG>, the patient <NUM> is undergoing a surgical procedure, and the anatomy includes a femur (F) and a tibia (T) of the patient <NUM>. The surgical procedure may involve tissue removal. In some embodiments, the surgical procedure involves partial or total knee or hip replacement surgery. The system <NUM> is designed to cut away material to be replaced by surgical implants such as hip and knee implants, including unicompartmental, bicompartmental, total knee implants, and other types of prosthetics. Some of these types of implants are disclosed in <CIT>, entitled, "Prosthetic Implant and Method of Implantation". It should be appreciated that the system <NUM> disclosed herein may be used to perform other procedures, either surgical or non-surgical, and/or may be used in industrial applications or other applications.

The system <NUM> includes a surgical manipulator <NUM> (e.g., a surgical robot). The manipulator <NUM> has a base <NUM> and a linkage <NUM> (e.g., an articulable robotic arm). The linkage <NUM> may include links forming a serial arm or parallel arm configuration. A tool <NUM> couples to the manipulator <NUM> and is movable relative to the base <NUM> via the linkage <NUM> to interact with the anatomy of the patient <NUM>. The tool <NUM> forms part of an end effector <NUM> attached to the manipulator <NUM>. The tool <NUM> is grasped by the operator (e.g., a surgeon) in some embodiments. One exemplary arrangement of the manipulator <NUM> and the tool <NUM> is described in <CIT>, entitled, "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes". The manipulator <NUM> and the tool <NUM> may be arranged in alternative configurations. The tool <NUM> comprises an energy applicator <NUM> to contact the tissue of the patient <NUM> at a surgical site. The energy applicator <NUM> may be a drill, a saw blade, a bur, an ultrasonic vibrating tip, or the like. Other configurations are contemplated. The manipulator <NUM> houses a manipulator computer <NUM>, or other type of control unit.

The system <NUM> includes a controller which includes software and/or hardware for controlling the manipulator <NUM>. The controller directs the motion of the manipulator <NUM> and controls a position and orientation of the tool <NUM> with respect to a coordinate system. In one embodiment, the coordinate system is a manipulator coordinate system MNPL (see <FIG>). The manipulator coordinate system MNPL has an origin, and the origin is located relative to the manipulator <NUM>. One example of the manipulator coordinate system MNPL is described in <CIT>, entitled, "Surgical Manipulator Capable of Controlling a Surgical Instrument in Multiple Modes," previously referenced.

The system <NUM> further includes a navigation system <NUM>. One example of the navigation system <NUM> is described in <CIT>, entitled, "Navigation System Including Optical and Non-Optical Sensors". The navigation system <NUM> is set up to track movement of various objects. Such objects include, for example, the tool <NUM>, and the anatomy, e.g., femur F and tibia T. The navigation system <NUM> tracks these objects to gather position information of each object in a localizer coordinate system LCLZ. Coordinates in the localizer coordinate system LCLZ may be transformed to the manipulator coordinate system MNPL using conventional transformation techniques. In some embodiments, the navigation system <NUM> is also capable of displaying a virtual representation of their relative positions and orientations to the operator.

The navigation system <NUM> includes a computer cart assembly <NUM> that houses a navigation computer <NUM>, and/or other types of control units. A navigation interface is in operative communication with the navigation computer <NUM>. The navigation interface includes one or more displays <NUM>. First and second input devices <NUM>, <NUM> such as touch screen inputs may be used to input information into the navigation computer <NUM> or otherwise select/control certain aspects of the navigation computer <NUM>. Other input devices are contemplated, including a keyboard, mouse, voice-activation, and the like. The controller may be implemented on any suitable device or devices in the system <NUM>, including, but not limited to, the manipulator computer <NUM>, the navigation computer <NUM>, and any combination thereof.

The navigation system <NUM> also includes a localizer <NUM> that communicates with the navigation computer <NUM>. In one embodiment, the localizer <NUM> is an optical localizer and includes a camera unit <NUM>. The camera unit <NUM> has an outer casing <NUM> that houses one or more optical position sensors <NUM>. The system <NUM> also includes one or more trackers. The trackers may include a pointer tracker PT, a tool tracker <NUM>, a first patient tracker <NUM>, and a second patient tracker <NUM>. The trackers include active markers <NUM>. The active markers <NUM> may be light emitting diodes or LEDs. In other embodiments, the trackers <NUM>, <NUM>, <NUM> may have passive markers, such as reflectors, which reflect light emitted from the camera unit <NUM>. It should be appreciated that other suitable tracking systems and methods not specifically described herein may be utilized.

In the illustrated embodiment of <FIG>, the first patient tracker <NUM> is firmly affixed to the femur F of the patient <NUM> and the second patient tracker <NUM> is firmly affixed to the tibia T of the patient <NUM>. The patient trackers <NUM>, <NUM> are firmly affixed to sections of bone. The tool tracker <NUM> is firmly attached to the tool <NUM>. It should be appreciated that the trackers <NUM>, <NUM>, <NUM> may be fixed to their respective components in any suitable manner.

The trackers <NUM>, <NUM>, <NUM> communicate with the camera unit <NUM> to provide position data to the camera unit <NUM>. The camera unit <NUM> provides the position data of the trackers <NUM>, <NUM>, <NUM> to the navigation computer <NUM>. In one embodiment, the navigation computer <NUM> determines and communicates position data of the femur F and tibia T and position data of the tool <NUM> to the manipulator computer <NUM>. Position data for the femur F, tibia T, and tool <NUM> may be determined by the tracker position data using conventional registration/navigation techniques. The position data include position information corresponding to the position and/or orientation of the femur F, tibia T, tool <NUM>, and/or any other objects being tracked. The position data described herein may be position data, orientation data, or a combination of position data and orientation data.

The manipulator computer <NUM> transforms the position data from the localizer coordinate system LCLZ into the manipulator coordinate system MNPL by determining a transformation matrix using the navigation-based data for the tool <NUM> and encoder-based position data for the tool <NUM>. Encoders (not shown) located at joints of the manipulator <NUM> are used to determine the encoder-based position data. The manipulator computer <NUM> uses the encoders to calculate an encoder-based position and orientation of the tool <NUM> in the manipulator coordinate system MNPL. Since the position and orientation of the tool <NUM> are also known in the localizer coordinate system LCLZ, the transformation matrix may be generated.

In one embodiment, the controller includes a manipulator controller <NUM> for processing data to direct motion of the manipulator <NUM>. The manipulator controller <NUM> may receive and process data from a single source or from multiple sources.

The controller further includes a navigation controller <NUM> for communicating the position data relating to the femur F, tibia T, and tool <NUM> to the manipulator controller <NUM>. The manipulator controller <NUM> receives and processes the position data provided by the navigation controller <NUM> to direct movement of the manipulator <NUM>. In one embodiment, as shown in <FIG>, the navigation controller <NUM> is implemented on the navigation computer <NUM>.

The manipulator controller <NUM> or navigation controller <NUM> may also communicate positions of the patient <NUM> and the tool <NUM> to the operator by displaying an image of the femur F and/or tibia T and the tool <NUM> on the display <NUM>. The manipulator computer <NUM> or navigation computer <NUM> may also display instructions or request information on the display <NUM> such that the operator may interact with the manipulator computer <NUM> for directing the manipulator <NUM>. Other configurations are contemplated.

Referring to <FIG>, in some embodiments, the tool <NUM> includes a drive system <NUM> that converts electrical signals into a form of energy that is applied to the patient. This energy may be mechanical, ultrasonic, thermal, RF, EM, photonic, combinations thereof, and the like. The energy is applied to the patient <NUM> through the energy applicator <NUM>. In the representative embodiment shown, the end effector <NUM> includes a mounting fixture <NUM> for removably attaching the tool <NUM> to the manipulator <NUM>. In the embodiment shown, the energy applicator <NUM> is configured to remove tissue of the patient. As shown in the Figures, the energy applicator <NUM> comprises a bur. Alternative to a bur, the energy applicator <NUM> may comprise any type of surgical tool for material cutting, material removal, or other tissue manipulation or treatment at a surgical site.

With reference to <FIG> and <FIG>, in the embodiment shown, the energy applicator <NUM> includes a working portion comprising a head <NUM> for cutting tissue of the patient <NUM>, and a shaft <NUM> extending along a tool axis T between a proximal end <NUM> and a distal end <NUM>. The shaft <NUM> includes an outer surface <NUM> in which an annular groove or recess <NUM> is disposed. The groove or recess <NUM> is arranged axially between the proximal end <NUM> and the distal end <NUM>, and extends radially inward toward the tool axis T to a bottom <NUM>. Put differently, the groove or annular recess <NUM> depends inwardly from the outer surface <NUM> to the bottom <NUM>. As is explained in greater detail below, the groove or annular recess <NUM> at least partially defines an axial-force receiving surface to promote axial retention of the energy applicator <NUM>.

The groove or annular recess <NUM> has a distal surface <NUM> and a sloped surface <NUM>, each of which extends from the outer surface <NUM> of the shaft <NUM> to the bottom <NUM>. In the illustrated embodiment, the distal surface <NUM> has a generally toroidal profile and is arranged axially between the distal end <NUM> and the bottom <NUM>, and the sloped surface <NUM> has a generally conical profile and is arranged axially between the bottom <NUM> and the proximal end <NUM>. As shown in <FIG>, the conical, sloped surface <NUM> is formed extending along a first axial distance AD1 from the outer surface <NUM> to the bottom <NUM>, and the distal surface <NUM> is formed extending along a second axial distance AD2, less than the first axial distance AD1, from the outer surface <NUM> to the bottom <NUM>. It will be appreciated that the annular groove or recess <NUM> could have different configurations sufficient to promote axial retention of the energy applicator <NUM>.

The conical, sloped surface <NUM> is arranged at an acute angle α<NUM> relative to the axis T (see <FIG>). In some embodiments, the acute angle α<NUM> is greater than zero degrees and less than <NUM> degrees. In other embodiments, the acute angle α<NUM> is <NUM>-<NUM> degrees, <NUM>-<NUM> degrees, or <NUM>-<NUM> degrees, relative to the axis T. The shaft <NUM> may include a passage <NUM> (see <FIG>) extending axially between the proximal end <NUM> and the distal end <NUM> for purposes of irrigation and/or suction. In the embodiment shown, the head <NUM> and shaft <NUM> of the energy applicator <NUM> are integral, unitary, and one-piece, but could be separate parts in other embodiments.

Referring to <FIG>, a protective sheath <NUM> supports the energy applicator <NUM>. The protective sheath <NUM> comprises a nose tube <NUM> and defines a protective sheath bore <NUM> (see <FIG>) and receives the shaft <NUM> of the energy applicator <NUM> in the protective sheath bore <NUM>. The protective sheath <NUM> includes an enlarged end portion <NUM> which is configured for releasable attachment, as is described in greater detail below. The nose tube <NUM> is formed integrally with and extends from the end portion <NUM>, and a distal bushing <NUM> is attached to the distal end of the nose tube <NUM>. The distal bushing <NUM> is configured to be concentrically disposed about the shaft <NUM> of the energy applicator <NUM>. As is depicted in <FIG>, the distal bushing <NUM> has a first inner diameter ID1, and the nose tube <NUM> has a second inner diameter ID2 which is larger than the first inner diameter ID2. Here too in <FIG>, the end portion <NUM> has a first outer diameter OD1 and the nose tube <NUM> has a second outer diameter OD2 which is smaller than the first outer diameter OD2.

The enlarged end portion <NUM> has a cavity <NUM> and at least one bearing <NUM>, shown for example in <FIG>, disposed in the cavity <NUM>. In some embodiments, the protective sheath <NUM> and the bearing <NUM> form a releasably attachable protective sheath assembly <NUM> (see <FIG>). The bearing <NUM> is configured to receive and rotatably support the shaft <NUM> in the protective sheath bore <NUM>. The enlarged end portion <NUM> has one or more outer grooves <NUM> extending axially. The grooves <NUM> are circumferentially and equally spaced about an outer periphery of the enlarged end portion <NUM>. The grooves <NUM> are spaced circumferentially about the outer surface and extend from a proximal end of the enlarged end portion <NUM> to a detent pocket <NUM>. In the illustrated embodiments, the grooves <NUM> are shallower than their corresponding detent pockets <NUM>, and extend axially from the respective detent pockets <NUM> to the proximal end of the end portion <NUM> of the protective sheath <NUM>. However, it will be appreciated that other configurations are contemplated.

An axial connector assembly <NUM> couples the energy applicator <NUM> and the protective sheath <NUM> to a support structure <NUM> (see <FIG>). As set forth further below, the connector assembly <NUM> supports the protective sheath <NUM> and is configured to support or lock the energy applicator <NUM> relative to the protective sheath <NUM>. The axial connector assembly <NUM> and the support structure <NUM> are concentrically disposed relative to each other along the axis T. The axial connector assembly <NUM> releasably engages the energy applicator <NUM> and the protective sheath <NUM> such that both of the energy applicator <NUM> and the protective sheath <NUM> are replaceable components.

Referring to <FIG>, in the illustrated embodiment, the support structure <NUM> includes a support sleeve <NUM> extending axially. The support sleeve <NUM> is generally cylindrical in shape. The support sleeve <NUM> has a hollow interior cavity <NUM> with a plurality of internal threads <NUM> at a distal end thereof. The axial connector assembly <NUM> includes a connector member <NUM> to facilitate releasable connection of the protective sheath <NUM> to the support sleeve <NUM>. The connector member <NUM> includes a plurality of exterior threads <NUM> to threadably engage the interior threads <NUM> of the support sleeve <NUM>. The connector member <NUM> is generally cylindrical in shape.

The connector member <NUM> includes an interior wall <NUM> extending radially inwardly to act as a stop for the enlarged end portion <NUM> of the protective sheath <NUM> when inserting the protective sheath <NUM> into the connector member <NUM>. The interior wall <NUM> has an aperture <NUM> extending axially therethrough to allow the shaft <NUM> of the energy applicator <NUM> to extend therethrough. The connector member <NUM> includes a flange <NUM> extending radially outward to engage an interior surface of the support sleeve <NUM>.

The connector member <NUM> also includes one or more openings <NUM> (see also <FIG>) extending radially therethrough. The openings <NUM> are disposed axially between the interior wall <NUM> and the flange <NUM>. In the embodiment shown, the connector member <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments.

The axial connector assembly <NUM> also includes at least one engagement member <NUM> to releasably couple the protective sheath <NUM> to the connector member <NUM>. In one embodiment, a plurality of engagement members <NUM> are used with one engagement member <NUM> disposed in each opening <NUM>. Each of the engagement members <NUM> is generally spherical in shape. In the embodiment shown, the engagement members <NUM> are ball bearings, such as those formed of stainless steel or other suitable materials. The axial connector assembly <NUM> can include any number of engagement members <NUM> and corresponding openings <NUM>.

The axial connector assembly <NUM> also includes a resilient member <NUM> disposed about the engagement members <NUM>. The resilient member <NUM> may be an O-ring seal, but may have other forms, such as a compression spring or other type of spring. The resilient member <NUM> presses the engagement members <NUM> into their corresponding openings <NUM> to facilitate a releasable connection to the enlarged end portion <NUM> of the protective sheath <NUM>.

Each of the openings <NUM> are sized and shaped so that the engagement members <NUM> are capable of being exposed on either side of the openings <NUM>. By being exposed on a radially outward side of the openings <NUM>, the resilient member <NUM> can apply a biasing force to the engagement members <NUM>. By being exposed on a radially inward side of the openings <NUM>, the engagement members <NUM> are able to engage the enlarged end portion <NUM> of the protective sheath <NUM>. The openings <NUM> may be sized and shaped to receive the engagement members <NUM> without allowing the engagement members <NUM> to fall through the openings <NUM> when the protective sheath <NUM> is absent. For instance, the openings <NUM> could be tapered radially inwardly to a diameter sized to retain the engagement members <NUM>.

When axially coupling the protective sheath <NUM> to the connector member <NUM> (which is already fixed to the support sleeve <NUM>), the engagement members <NUM> are sized and shaped to move along and within the grooves <NUM> defined in the enlarged end portion <NUM>, under constant bias of the resilient member <NUM> until the engagement members <NUM> reach (e.g., are radially aligned with) the detent pockets <NUM>. At that point, the engagement members <NUM> are seated in the detent pockets <NUM> thereby holding the protective sheath <NUM> to the connector member <NUM> by virtue of the bias associated with the resilient member <NUM>. The protective sheath <NUM> may be removed by pulling on the protective sheath <NUM> distally to overcome the bias and urge the engagement members <NUM> out from the detent pockets <NUM>.

The protective sheath <NUM> may require replacement when the bearing <NUM> is worn. Accordingly, by having the bearing <NUM> supported in the protective sheath <NUM> and making the protective sheath <NUM> removable and replaceable, significant down time can be avoided that might otherwise exist if the entire end effector <NUM> needed to be taken out of circulation to replace the bearing <NUM>.

The protective sheath <NUM> defines one or more weep holes <NUM> extending radially therethrough. The weep holes <NUM> may be spaced axially and/or circumferentially about the protective sheath <NUM>. In the embodiment shown, a first pair of diametrically opposing weep holes <NUM> are located near the enlarged end portion <NUM> of the protective sheath <NUM> at a first axial distance from the enlarged end portion <NUM>. A second pair of diametrically opposing weep holes <NUM> are located further away from the enlarged end portion <NUM> at a second axial distance. The second pair of weep holes <NUM> are also located on the protective sheath <NUM> with approximately <NUM> degrees of circumferential separation from the first pair of weep holes <NUM>. The weep holes <NUM> are intended to prevent fluid from the surgical site coming into contact with the bearing <NUM>, which may otherwise shorten the operational life of the bearing <NUM>. During use, and owing to temperature gradients in the tool <NUM> and capillary effects, fluid may tend to move between the shaft <NUM> of the energy applicator <NUM> and the protective sheath <NUM> toward the bearing <NUM>. The weep holes <NUM> provide a suitable escape for such fluid before it reaches the bearing <NUM>.

Still referring to <FIG>, the axial connector assembly <NUM> includes a bushing <NUM> disposed within the connector member <NUM> at a proximal end of the connector member <NUM>. The bushing <NUM> is generally cylindrical in shape with an aperture <NUM> extending axially therethrough. In some embodiments, the bushing <NUM> is fixed axially to the support sleeve <NUM> and/or the connector member <NUM>. Alternatively, the bushing <NUM> may be floating within the support sleeve <NUM>.

The axial connector assembly <NUM> further includes a cam member <NUM>. The cam member <NUM> can also be referred to as a wedge member. The cam member <NUM> includes a reduced diameter portion <NUM> disposed in the aperture <NUM> of the bushing <NUM> to rotate relative to the support sleeve <NUM>. The cam member <NUM> rotates relative to the support sleeve <NUM>. The cam member <NUM> includes a cavity <NUM> extending axially from the proximal end thereof. The cavity <NUM> includes a tapered or sloped surface <NUM> (also referred to as a cam surface or a wedge surface) extending axially and radially inward. In the embodiment shown, the sloped surface <NUM> is in the form of a conical surface. The sloped surface <NUM> is arranged at an acute angle α<NUM> relative to the tool axis T. In some embodiments, the sloped surface <NUM> is at an acute angle α<NUM> greater than zero degrees and less than <NUM> degrees. In other embodiments, the acute angle α<NUM> is <NUM>-<NUM> degrees, <NUM>-<NUM> degrees, or <NUM>-<NUM> degrees, relative to the axis T. The acute angles α<NUM> and α<NUM> are sized so that at least one engagement member <NUM>, described further below, becomes wedged between the sloped surfaces <NUM>, <NUM> to hold the shaft <NUM> of the energy applicator <NUM>, yet is readily releasable from the shaft <NUM>. The difference in the acute angles α<NUM> and α<NUM> may be <NUM>-<NUM> degrees, <NUM>-<NUM> degrees, <NUM>-<NUM> degrees, or <NUM> degrees relative to the axis T.

The axial connector assembly <NUM> includes a locking sleeve <NUM> disposed within the support sleeve <NUM>. The locking sleeve <NUM> extends axially. The locking sleeve <NUM> is generally cylindrical in shape. The locking sleeve <NUM> has a passage <NUM> extending axially therethrough to receive the shaft <NUM>. The locking sleeve <NUM> also includes a plurality of openings <NUM> extending radially therethrough near a distal end thereof to receive the engagement members <NUM>. The openings <NUM> are sized and shaped to allow the engagement members <NUM> to be exposed radially inwardly relative to the locking sleeve <NUM> to engage the sloped surface <NUM>. The openings <NUM> are also sized and shaped to allow the engagement members <NUM> to be exposed radially outwardly relative to the locking sleeve <NUM> to engage the sloped surface <NUM>. The openings <NUM> may be sized and shaped to prevent the engagement members <NUM> from passing completely through the openings <NUM> thereby retaining the engagement members <NUM>. The locking sleeve <NUM> includes a flange <NUM> extending radially outwardly. In the embodiment shown, the locking sleeve <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments.

The engagement members <NUM> couple the shaft <NUM> to the cam member <NUM>. In one embodiment, a plurality of engagement members <NUM> are used with one engagement member <NUM> disposed in each opening <NUM> of the locking sleeve <NUM>. Each of the engagement members <NUM> is generally spherical in shape. It should be appreciated that the axial connector assembly <NUM> may include any number of engagement members <NUM> and corresponding openings <NUM>. In the embodiment shown, the engagement members <NUM> are ball bearings, such as those formed of stainless steel or other suitable materials.

The axial connector assembly <NUM> also includes a bushing <NUM> disposed about the locking sleeve <NUM> and within the support sleeve <NUM>. The bushing <NUM> is generally cylindrical in shape with an aperture <NUM> extending axially therethrough to allow the locking sleeve <NUM> to extend therethrough. The bushing <NUM> is fixed relative to the support sleeve <NUM> in the embodiment shown. In other embodiments, the bushing <NUM> is free to float within the support sleeve <NUM> between the cam member <NUM> and the locking sleeve <NUM>.

The axial connector assembly <NUM> further includes a ring member <NUM> disposed about the locking sleeve <NUM> between the bushing <NUM> and the flange <NUM>. The ring member <NUM> is generally cylindrical in shape. The ring member <NUM> has one or more pockets <NUM> extending radially therein. In one embodiment, a pair of opposed pockets <NUM> extend radially therein.

The support structure <NUM> includes one or more slots <NUM> in the support sleeve <NUM>. The slots <NUM> extend radially therethrough and are arranged helically about an axis of the support sleeve <NUM>. In the embodiment shown, opposing slots <NUM> are formed helically in the support sleeve <NUM>. The slots <NUM> in the embodiment shown are located only partially about the support sleeve <NUM>. The support structure <NUM> also includes one or more engagement members <NUM> disposed in the slots <NUM> and pockets <NUM> of the ring member <NUM>. One of the engagement members <NUM> is disposed in each of the slots <NUM> and pockets <NUM>. In the embodiment shown, the engagement members <NUM> are ball bearings, such as those formed of stainless steel or other suitable materials. However, other configurations are contemplated.

With reference to <FIG>, a collet assembly <NUM> cooperates with the support structure <NUM> to move the axial connector assembly <NUM> between locked and unlocked states. The collet assembly <NUM> includes a lock collar <NUM> which is movable relative to the support structure <NUM>. The lock collar <NUM> is elongated axially. The lock collar <NUM> is generally cylindrical in shape. The lock collar <NUM> is disposed about a portion of the support sleeve <NUM> of the support structure <NUM>.

Referring to <FIG> and <FIG>, the lock collar <NUM> includes a wall <NUM> that defines cutouts <NUM> spaced circumferentially about the wall <NUM> and extending axially. The lock collar <NUM> includes one or more recesses <NUM> (see <FIG>) extending axially inward from the distal end. The lock collar <NUM> also includes one or more pockets <NUM> (only one shown in <FIG>) at a distal end extending axially inward. The collet assembly <NUM> also includes a release member coupled to the lock collar <NUM> which is configured to be actuated by the user to move the lock collar <NUM>, such as to place the connector assembly <NUM> in the unlocked state. To this end, and in the embodiment illustrated in <FIG>, the release member comprises a gripping member <NUM> at a proximal end of the lock collar <NUM> to be grasped by a user. The gripping member <NUM> is generally cylindrical in shape. It should be appreciated that the lock collar <NUM> may be rotated relative to the support sleeve <NUM> of the support structure <NUM>.

The collet assembly <NUM> also includes a spring member <NUM> disposed within the lock collar <NUM>. The spring member <NUM> extends axially. In the embodiment shown, the spring member <NUM> is a helical torsion spring. The spring member <NUM> is generally cylindrical in shape. The spring member <NUM> includes a plurality of convolutions <NUM>. The spring member <NUM> includes at least one or more distal tabs <NUM> extending axially at a distal end. The distal tabs <NUM> are disposed inside the opposing pockets <NUM> of the lock collar <NUM> and are fixed to the lock collar <NUM>. The spring member <NUM> includes at least one or more proximal tabs <NUM> extending axially at a proximal end.

The collet assembly <NUM> includes a first collar member <NUM> disposed over the support sleeve <NUM> of the support structure <NUM>. The first collar member <NUM> is generally cylindrical in shape. The first collar member <NUM> includes a plurality of protrusions <NUM> extending axially and radially outward and a plurality of recesses <NUM> (one partially shown in <FIG>) extending axially inward from a proximal end. The first collar member <NUM> also includes a recess <NUM> in two of the opposed protrusions <NUM> to receive the tabs <NUM> of the spring member <NUM>.

The collet assembly <NUM> further includes a second collar member <NUM> disposed over the support sleeve <NUM> of the support structure <NUM>. The second collar member <NUM> is generally cylindrical in shape. The second collar member <NUM> includes a plurality of protrusions <NUM> extending axially and radially outward. The second collar member <NUM> includes one or more recesses <NUM> extending axially through two of the opposed protrusions <NUM>. The collet assembly <NUM> further includes a bushing <NUM> disposed against the flange <NUM> of the locking sleeve <NUM> to rotatably support the locking sleeve <NUM> in the support sleeve <NUM>.

As illustrated, the axial connector assembly <NUM>, support structure <NUM>, and collet assembly <NUM> form a tool assembly <NUM>. The tool assembly <NUM> includes a coil spring <NUM> disposed within the support sleeve <NUM> of the support structure <NUM>. The coil spring <NUM> has a distal end that abuts the bushing <NUM>. The tool assembly <NUM> includes a plurality of rods <NUM> disposed in grooves <NUM> extending axially along an outer periphery of the support sleeve <NUM> of the support structure <NUM>. The rods <NUM> are also disposed in the recesses <NUM> of the first collar member <NUM> and the recesses <NUM> of the second collar member <NUM>. It should be appreciated that the rods <NUM> key and rotatably fix the first collar member <NUM> and the second collar member <NUM> to the support sleeve <NUM>.

In operation of the collet assembly <NUM>, a user grasps the gripping member <NUM> and rotates the lock collar <NUM> clockwise (when viewed from the distal end) to allow disengagement of the energy applicator <NUM>. As the lock collar <NUM> is rotated, the rods <NUM> rotationally lock the first collar member <NUM> and the second collar member <NUM> to the support sleeve <NUM>. The lock collar <NUM> thus rotates against the bias of the spring member <NUM> (since the proximal end of the spring member <NUM> is prevented from rotating).

When rotating the lock collar <NUM>, the engagement members <NUM> (e.g., ball bearings) are also moved in the slots <NUM> by virtue of the engagement members <NUM> being coupled to the lock collar <NUM>, i.e., the engagement members <NUM> are positioned within the recesses <NUM> located in the distal end of the lock collar <NUM>. Accordingly, movement of the engagement members <NUM> is controlled by rotation of the lock collar <NUM>. Due to the helical nature of the slots <NUM>, when moved by the lock collar <NUM>, the engagement members <NUM> follow their corresponding helical paths such that the engagement members <NUM> are moved both in a planetary fashion about the tool axis T and axially with respect to the tool axis T toward the proximal end of the support sleeve <NUM>. The lock collar <NUM> is configured to rotate, but not to translate relative to the axis T. As a result, the recesses <NUM> are axially elongated, so that as the lock collar <NUM> is rotated, and the engagement members <NUM> follow the helical paths in the slots <NUM>, the engagement members <NUM> also translate within the recesses <NUM>. In other embodiments, the lock collar <NUM> may also translate axially with the engagement members <NUM>.

Axial movement of the ring member <NUM> is facilitated by the engagement members <NUM> being seated in the pockets <NUM> of the ring member <NUM> and captured between the pockets <NUM> and the recesses <NUM>. In essence, the lock collar <NUM> is coupled to the ring member <NUM> through the engagement members <NUM>. As a result, when the engagement members <NUM> are moved along their helical paths in the slots <NUM>, the ring member <NUM> follows the engagement members <NUM> and is partially rotated and moved axially towards the flange <NUM>. First, the ring member <NUM> reaches the flange <NUM> of the locking sleeve <NUM>, and thereafter moves the locking sleeve <NUM> and associated bushing <NUM> proximally against the bias of spring <NUM>. The engagement members <NUM> that were wedged between the sloped surfaces <NUM>, <NUM> of the shaft <NUM> and the cam member <NUM> are thereby released from their wedged arrangement away from the sloped surface <NUM> defining the groove <NUM> of the shaft <NUM> to unlock the shaft <NUM> and allow removal of the energy applicator <NUM>. This defines the unlocked state of the axial connector assembly <NUM>. Since the slots <NUM> in the embodiment shown are only partially defined about the support sleeve <NUM>, only partial rotation of the lock collar <NUM> is required to unlock the shaft <NUM> and allow removal of the energy applicator <NUM>. The rotation required may be <NUM> degrees or less, <NUM> degrees or less, or <NUM> degrees or less.

When the gripping member <NUM> is released, the spring member <NUM> returns to its normal state thereby moving the engagement members <NUM> in the slots <NUM> in a reverse direction along their helical paths, which moves the ring member <NUM> distally to disengage the flange <NUM> of the locking sleeve <NUM>, which allows the spring <NUM> to push the locking sleeve <NUM> back toward the cam member <NUM>. The engagement members <NUM> fall back into the groove <NUM> against the sloped surface <NUM> of the shaft <NUM> of the energy applicator <NUM> and wedge against the sloped surface <NUM> to lock the shaft <NUM>. This defines the locked state of the axial connector assembly <NUM>. The collet assembly <NUM> operates the axial connector assembly <NUM> between the locked and unlocked states.

It should be appreciated that, when the energy applicator <NUM> is connected and locked to the tool assembly <NUM>, the collet assembly <NUM> cooperates with the axial connector assembly <NUM> to apply a force to keep the proximal end <NUM> of the energy applicator <NUM> abutting against a shoulder <NUM> of the tool assembly <NUM>. In particular, when the engagement members <NUM> are wedged between the sloped surfaces <NUM>, <NUM>, under the influence of the spring <NUM>, these engagement members <NUM> impart a force directed against the sloped surface <NUM> of the energy applicator <NUM>. This force includes an axial component applied against the energy applicator in the proximal direction to maintain the abutting contact between the proximal end <NUM> of the energy applicator <NUM> and the shoulder <NUM> (or other reference surface fixed relative to the support structure <NUM>). Thus, the sloping surface <NUM> of the energy applicator <NUM> may also be referred to as an axial-force receiving surface.

One purpose of the abutment between the proximal end <NUM> and the shoulder <NUM> is to consistently match up and enable communication between an identification tag (e.g., a radio frequency identification tag RFID) on the energy applicator <NUM> and a radio frequency identification reader <NUM> (<FIG>) on the tool assembly <NUM>. This engagement of the proximal end <NUM> of the energy applicator and the shoulder <NUM> also provides repeatability in establishing the location (e.g., position in X, Y, Z coordinates) of a tool center point (TCP) of the energy applicator <NUM> for purposes of surgical navigation as described herein. For instance, the location of the TCP may be calibrated during manufacture and the details of the calibration, e.g., calibration data, thereafter stored in the RFID tag or other non-volatile memory for retrieval by a tool controller (not shown) that controls operation of the tool <NUM>, the manipulator controller <NUM>, and/or the navigation controller <NUM>. By virtue of having a consistent interface (e.g., abutting contact) between the tool assembly <NUM> and the energy applicator <NUM>, the system <NUM> (which includes the navigation system <NUM>) is capable of retrieving the calibration data to readily determine the TCP in a coordinate system of the tool <NUM> or other coordinate system with high accuracy. Accordingly, the shoulder <NUM> provides a reference location from which to locate the TCP.

Referring to <FIG>, a drive assembly <NUM> of the tool <NUM> is shown. The drive assembly <NUM> includes a drive member <NUM>, e.g., a rotating drive shaft. The drive member <NUM> is generally cylindrical in shape. The drive member <NUM> includes a cavity <NUM> (see <FIG>) extending axially inwardly from a proximal end, a cavity <NUM> extending axially inwardly from a distal end, and a passage <NUM> extending axially between the cavities <NUM> and <NUM>. The drive member <NUM> includes a seal <NUM> disposed in the cavity <NUM> and a seal <NUM> disposed in the cavity <NUM>. The drive member <NUM> includes a flange <NUM> extending circumferentially and radially outward. The drive member <NUM> further includes a pair of opposed flanges <NUM> extending axially from a proximal end. In the embodiment shown, the drive member <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments. It should be appreciated that the seal <NUM> seals against a rotatable shaft <NUM> of an actuator <NUM> (see <FIG>) to be described and the seal <NUM> seals against the shaft <NUM> of the energy applicator <NUM>. In the embodiment shown, the seal <NUM> may comprise a lip seal.

The drive assembly <NUM> also includes a driven member <NUM> coupled to the drive member <NUM>. The driven member <NUM> extends axially. The driven member <NUM> is generally cylindrical in shape. The driven member <NUM> is disposed about the distal end of the drive member <NUM> and abuts the flange <NUM>. In the embodiment shown, the driven member <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments.

The drive assembly <NUM> includes a drive connector <NUM> coupled to the driven member <NUM> to rotate with the driven member <NUM>. The drive connector <NUM> is generally cylindrical in shape. The drive connector <NUM> includes a cavity <NUM> extending axially inwardly from a proximal end and a cavity <NUM> extending axially inwardly from a distal end. The drive connector <NUM> includes a flange <NUM> extending circumferentially and radially outward that abuts the distal end of the driven member <NUM>. In the embodiment shown, the drive connector <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments.

The drive assembly <NUM> further includes a clutch assembly <NUM> disposed within the driven member <NUM> and configured to slideably receive the shaft <NUM> of the energy applicator <NUM>. The clutch assembly <NUM> is supported by the driven member <NUM> and rotatable relative to the drive member <NUM>. The clutch assembly <NUM> receives the shaft <NUM> of the energy applicator <NUM> for selectively coupling the shaft <NUM> to the drive member <NUM>. Specifically, the shaft <NUM> is slideable into the clutch assembly <NUM> and is slideable out of the clutch assembly <NUM>.

With reference to <FIG>, the clutch assembly <NUM> includes a plurality of roller holders <NUM> spaced axially and disposed within the driven member <NUM>. Each of the roller holders <NUM> is generally cylindrical in shape. In the embodiment shown, each of the roller holders <NUM> are generally disc-shaped. Each of the roller holders <NUM> includes an interior aperture <NUM> extending axially therethrough. Each of the roller holders <NUM> also includes opposed flanges <NUM> extending radially inward. Each of the roller holders <NUM> includes a secondary aperture <NUM> extending axially through one of the flanges <NUM> and spaced from the interior aperture <NUM>. Each of the roller holders <NUM> includes a recess <NUM> extending radially into the opposing flange <NUM>. In the embodiment shown, each of the roller holders <NUM> is integral, unitary, and one-piece, but could be separate parts in other embodiments. In one embodiment, three roller holders <NUM> are disposed adjacent each other at a proximal end of the clutch assembly <NUM> and three roller holders <NUM> are disposed adjacent each other at a distal end. These two sets of roller holders <NUM> are spaced axially from one another and are collectively referred to as a cage. Each of the three roller holders <NUM> at each axial end are oriented so that their respective secondary apertures <NUM> and recesses <NUM> are arranged approximately <NUM> degrees circumferentially relative to each other.

The clutch assembly <NUM> also includes a plurality of rollers <NUM> coupled to the roller holders <NUM>. The rollers <NUM> extend axially. The rollers <NUM> are generally cylindrical in shape. Each of the rollers <NUM> has a shaft <NUM> extending axially from each axial end. The two shafts <NUM> of a first roller <NUM> are disposed in the apertures <NUM> of the two outermost (axially) roller holders <NUM>, the two shafts <NUM> of a second roller <NUM> are disposed in the apertures <NUM> of the two innermost (axially) roller holders <NUM>, and the two shafts <NUM> of a third roller <NUM> are disposed in the apertures <NUM> of the remaining two roller holders <NUM>. The rollers <NUM> are arranged to be generally parallel to the shaft <NUM> of the energy applicator <NUM> when the energy applicator <NUM> is coupled to the tool assembly <NUM>.

The clutch assembly <NUM> also includes a plurality of counterweights <NUM> coupled to the roller holders <NUM>. The counterweights <NUM> extend axially. The counterweights <NUM> are generally cylindrical in shape. One of the counterweights <NUM> is disposed in the recesses <NUM> of each pair of opposing roller holders <NUM>, i.e., the two outermost roller holders <NUM>, the two innermost roller holders <NUM>, and the remaining two roller holders <NUM>, so that there is one counterweight that corresponds to each roller <NUM>. It should be appreciated that the roller holders <NUM>, rollers <NUM>, and counterweights <NUM> are radially movable relative to the shaft <NUM> of the energy applicator <NUM>.

The clutch assembly <NUM> further includes a pair of resilient members <NUM> disposed about the rollers <NUM> and counterweights <NUM>. The resilient members <NUM> are spaced axially from each other. The resilient members <NUM> are of an O-ring type. The resilient members <NUM> are made of a flexible material. The resilient members <NUM> act to press the rollers <NUM> against the shaft <NUM> during initial insertion of the shaft <NUM> into the clutch assembly <NUM>. During insertion, the shaft <NUM> is located radially inward of the rollers <NUM>. The resilient members <NUM> provide enough biasing force so that once the shaft <NUM> is initially inserted, the rollers <NUM> frictionally engage and hold the shaft <NUM> from falling out of the clutch assembly <NUM> due to gravity, i.e., before the axial connector assembly <NUM> is moved back to the locked state to permanently hold the energy applicator <NUM> in place.

Referring to <FIG>, in operation of the clutch assembly <NUM>, when torque is applied and the driven member <NUM> is rotated, an inner cam surface <NUM> of the driven member <NUM> rotates until the inner cam surface <NUM> engages the rollers <NUM>. More specifically, the driven member <NUM> has a cross-sectional profile as shown in <FIG> that comprises a first region 251a of thickness T1, a second region 251b of thickness T2, which is less than T1, and the inner cam surface <NUM> is arcuate in shape from the first region 251a to the second region 251b to form cam regions 251c on either side of the second region 251b (only one labeled in <FIG>). The cam regions 251c, when rotated relative to the clutch assembly <NUM> (either direction) eventually engage the rollers <NUM> and hold the rollers <NUM> against the shaft <NUM>. In the embodiment shown, the outer surface of the driven member <NUM> is cylindrical.

During operation of the tool <NUM>, the counterweights <NUM> oppose any centrifugal forces that might otherwise act on the rollers <NUM> to pull the rollers <NUM> away from the shaft <NUM>. In other words, by virtue of being heavier than the rollers <NUM>, centrifugal forces acting on the counterweights <NUM> are larger than those acting on the rollers <NUM> thereby providing resultant forces that maintain contact of the rollers <NUM> with the shaft <NUM>, even at full speed. Roller <NUM>/counterweight <NUM> pairs are shown by dotted lines in <FIG> with their paired centers of gravity CG illustrated. Thus, the clutch assembly <NUM> is counterweighted to maintain contact of the rollers <NUM> with the shaft <NUM> when torque is applied to the driven member <NUM> by the actuator <NUM>.

The counterweights <NUM> may be made of denser material than the rollers <NUM>. In one embodiment, the counterweights <NUM> are formed of tungsten carbide and the rollers <NUM> are formed of stainless steel. So, even though the counterweights <NUM> may be smaller in volume, they are heavier so that the center of gravity CG of each roller <NUM>/counterweight <NUM> pair is located closer to the counterweight <NUM>. It should be appreciated that the clutch assembly <NUM> essentially floats inside the driven member <NUM> with enough space to accommodate some radial and/or axial movement of the roller holders <NUM>, rollers <NUM>, and counterweights <NUM>. In the embodiment shown, the clutch assembly <NUM> comprises three clutch subassemblies, each subassembly comprising a pair of the roller holders <NUM> and one roller <NUM>/counterweight <NUM> pair interconnecting the pair of the roller holders <NUM>. The clutch subassemblies are able to shift relative to one another within the driven member <NUM>.

Referring to <FIG> and <FIG>, the drive assembly <NUM> includes a washer <NUM> disposed between the seal <NUM> and the clutch assembly <NUM>. The drive assembly <NUM> further includes bushings <NUM> disposed about the drive member <NUM> and the drive connector <NUM> to support the drive member <NUM>, driven member <NUM>, drive connector <NUM>, and clutch assembly <NUM> for rotation within the support structure <NUM>. Bearings may be used in place of one or more of the bushings <NUM> in some embodiments.

Referring to <FIG>, the actuator <NUM> is coupled to the drive assembly <NUM> to form a drive system. More specifically, the actuator <NUM> is coupled to the drive member <NUM> to impart rotation to the drive member <NUM>. The actuator <NUM> is of a motor type and includes the shaft <NUM>. The shaft <NUM> engages the drive member <NUM> and the opposed flanges <NUM> to rotate the drive member <NUM>.

The support structure <NUM> further includes a floating collar or bushing <NUM> disposed about and movable relative to the support sleeve <NUM>. The floating collar <NUM> is generally cylindrical in shape. The floating collar <NUM> includes a raised portion <NUM> extending radially outward. The support structure <NUM> includes a retaining ring <NUM> disposed in a groove <NUM> (see <FIG>) in the support sleeve <NUM> to distally retain axial movement of the floating collar <NUM>. It should be appreciated that the floating collar <NUM> may be movable axially along and rotatably about the support sleeve <NUM>. In the embodiment shown, the floating collar <NUM> is rotatable about the support sleeve <NUM> and generally axially constrained between the retaining ring <NUM> and the lock collar <NUM>.

The tool assembly <NUM> also includes an outer floating sheath <NUM> rotatably disposed about a portion of the lock collar <NUM>. The floating sheath <NUM> is generally cylindrical in shape. The floating sheath <NUM> includes a pair of flanges <NUM> (see <FIG> and <FIG>) spaced from one another and extending outwardly in an equal and parallel manner from an outer surface of the floating sheath <NUM>. Each of the flanges <NUM> includes an aperture <NUM> extending therethrough.

Referring to <FIG>, a grip comprises a pair of grip members <NUM>. The grip members <NUM> are sized and shaped to engage the floating collar <NUM> and the second collar member <NUM> in a clam-shell manner about the outer floating sheath <NUM> so that the grip is able to rotate relative to the support sleeve <NUM> during operation. A trigger <NUM> is pivotally connected to the grip members <NUM> near a proximal end of the grip members <NUM> by a suitable mechanism such as a pin. During actuation, the trigger <NUM> pivots relative to the grip members <NUM>. The trigger <NUM> is also coupled to the outer floating sheath <NUM> by a link or lever <NUM> (see <FIG>). More specifically, the lever <NUM> is pivotally connected at one end to the flanges <NUM> of the outer floating sheath <NUM> by a suitable mechanism such as a pin. The other end of the lever <NUM> is pivotally connected to the trigger <NUM> at a location spaced from the pivot connection of the trigger <NUM> with the grip members <NUM>.

In operation, when the trigger <NUM> is depressed (toward the tool axis T), the trigger <NUM> applies a force on the link <NUM>, which in turn moves the link <NUM>. The link <NUM> is arranged at an acute angle to the tool axis T (see <FIG>) such that the link <NUM> applies an axially-directed force to the outer floating sheath <NUM> thereby moving the outer floating sheath <NUM> toward the actuator <NUM>. Since the outer floating sheath <NUM> axially abuts the protrusions <NUM> of the first collar member <NUM>, the first collar member <NUM> is also urged proximally. As previously described, the rods <NUM> are disposed in the recesses <NUM> of the first collar member <NUM> such that as the first collar member <NUM> moves proximally relative to the support sleeve <NUM>, the rods <NUM> are also pushed proximally. Proximal ends of the rods <NUM> are seated in pockets <NUM> (see <FIG>) in a switch actuator <NUM> such that proximal movement of the rods <NUM> causes the switch actuator <NUM> to also move proximally to activate a switch (not shown). A spring (not shown) acts against the switch actuator <NUM>, rods <NUM>, first collar member <NUM>, link <NUM>, and/or outer floating sheath <NUM> to return them to their pre-actuation position. Depression of the trigger <NUM> may be required to energize the actuator <NUM>, to switch between different modes, to enable operation of the tool <NUM>, or the like. Other functions of the trigger <NUM> are contemplated.

As noted above, another embodiment of the tool <NUM> is depicted in <FIG>. As will be appreciated from the subsequent description below, this embodiment is substantially similar to the embodiment illustrated in <FIG>, and both embodiments share similar structure and components, as well as similar features, advantages, and operational use. Thus, common structure and components between the embodiments are provided with the same reference numerals in the drawings and in the description below. Moreover, for the purposes of clarity, consistency, and brevity, certain structure and components common between the embodiments are not reintroduced or re-described below.

Referring now to <FIG>, the illustrated embodiment of the tool <NUM> similarly employs the tool assembly <NUM> to secure and drive the energy applicator <NUM>, which likewise has the axial-force receiving surface <NUM> formed in the shaft <NUM>. To this end, the tool assembly <NUM> similarly employs the support structure <NUM>, the axial connector assembly <NUM>, the drive system <NUM> and clutch assembly <NUM>, the collet assembly <NUM>, the reference surface <NUM>, and the protective sheath assembly <NUM>. Each of these components, structural features, and assemblies generally cooperate to facilitate operation of the tool <NUM> in the same way as described above in connection with the embodiment illustrated in <FIG>, but are arranged and configured differently as described below.

As shown in <FIG>, the illustrated tool assembly <NUM> likewise employs the release member and the lock collar <NUM> of the collet assembly <NUM> to facilitate movement of the axial connector assembly <NUM> between the locked state (see <FIG>, <FIG>) and the unlocked state (see <FIG>, <FIG>). However, in this embodiment, the lock collar <NUM> is slidably movable relative to the support structure <NUM>. In order to facilitate sliding movement of the lock collar <NUM>, the release member is realized in this embodiment as a release lever <NUM> which is coupled to the mounting fixture <NUM>. Here, a release mechanism, generally indicated at <NUM>, is interposed in force-translating relationship between the release lever <NUM> and the lock collar <NUM>.

The release mechanism <NUM> comprises a pair of arms <NUM>, an intermediate link <NUM>, and pins which cooperate to facilitate pivoting movement of the release lever <NUM> and the intermediate link <NUM> relative to the mounting fixture <NUM>. More specifically, an upper pin 269U, a lower pin <NUM>, and a middle pin <NUM> are provided in the illustrated embodiment. The upper pin 269U is coupled to the mounting fixture <NUM> and supports the intermediate link <NUM> for pivoting relative to the mounting fixture <NUM>. The lower pin <NUM> (shown in phantom in <FIG> and <FIG>) is coupled to the release lever <NUM> and supports the intermediate link <NUM> for pivoting relative to the release lever <NUM>. The middle pin <NUM> (shown in phantom in <FIG> and <FIG>) is coupled to the release lever <NUM> and is pivotally coupled to a portion <NUM> (shown in phantom in <FIG> and <FIG>) of the mounting fixture <NUM>. Each of the arms <NUM> has a first tab <NUM> which engages the lock collar <NUM>, and a second tab <NUM> which abuts the intermediate link <NUM>. As shown in <FIG>, the arms <NUM> translate in a direction substantially parallel to the tool axis T in response to pivoting movement of the intermediate link <NUM> resulting from corresponding movement of the release lever <NUM>. It will be appreciated that the release mechanism <NUM> could be arranged for actuation by the user in a number of different ways.

As shown in <FIG> and <FIG>, the lock collar <NUM> is biased axially via the spring member <NUM> which, in this embodiment, is realized as a cylindrical compression spring interposed between the support sleeve <NUM> and the lock collar <NUM> (see <FIG> and <FIG>). As a result of the force exerted on the lock collar <NUM> from the spring member <NUM>, the axial connector assembly <NUM> is biased toward the locked state. In addition to engaging and moving the lock collar <NUM>, the arms <NUM> also engage and facilitate movement of the ring member <NUM> which, in turn, abuts the flanges <NUM> of the locking sleeve <NUM>. Here, the locking sleeve <NUM> is biased by the spring <NUM> and similarly moves axially to bring the engagement members <NUM> into abutment between the axial-force receiving surface <NUM> of the energy applicator <NUM> and the tapered or sloped surface <NUM> of the cam member <NUM> (see <FIG>).

As shown in <FIG>, in the illustrated embodiment, the driven member <NUM> is coupled to a drive sleeve <NUM> which, in turn, is coupled to the cam member <NUM> such that the driven member <NUM>, the drive sleeve <NUM>, and the cam member <NUM> move concurrently. The drive sleeve <NUM> rotates with the drive member <NUM> via a coupling arrangement, generally indicated at <NUM>, which may comprise a keyed, splined, or similar arrangement of structural features which cooperate to engage and facilitate concurrent rotation. Adjacent to the coupling arrangement <NUM>, a preload assembly <NUM> with a preload spring <NUM> and a collar member <NUM> are provided. It will be appreciated that the driven member <NUM> could be coupled to the drive member <NUM> in a number of different ways.

Referring again to <FIG>, in the illustrated embodiment, the trigger <NUM> is similarly arranged for actuation by the user. Here too, movement of the trigger <NUM> causes corresponding movement of the link or lever <NUM>, which abuts and translates force to the outer floating sheath <NUM>. Here in this embodiment, the outer floating sheath <NUM> is disposed about the support sleeve <NUM> and translates axially in response to force acting on the trigger <NUM>, and a trigger return mechanism <NUM> with a return spring <NUM> facilitates limited, biased, axial movement of the outer floating sheath <NUM> relative to the support sleeve <NUM>. As shown in <FIG>, the outer floating sheath <NUM> is shaped such that movement of the trigger <NUM> causes corresponding movement of a trigger actuator <NUM> (e.g., a ball bearing) supported by a portion of the trigger return mechanism <NUM>. Here, movement of the trigger actuator <NUM> causes corresponding movement of a switch mechanism <NUM> (e.g., a piezoelectric switch) configured to facilitate operation of the tool assembly <NUM>, such as by generating a variable signal used to effect corresponding variable rotation of the actuator <NUM>. However, it will be appreciated that the trigger <NUM> could be configured in a number of different ways sufficient to facilitate operation of the tool assembly <NUM>.

As noted above, the embodiment illustrated in <FIG> also employs a removably-attachable protective sheath assembly <NUM>. Here too in this embodiment, the resilient member <NUM> biases one or more engagement members <NUM> toward the tool axis T and into engagement with the recesses <NUM> formed in the protective sheath <NUM>. It will be appreciated that any suitable number of engagement members <NUM> could be employed to engage in any suitable number of recesses <NUM>. In this embodiment, the protective sheath assembly <NUM> comprises a pair of bearings <NUM> supported in the protective sheath bore <NUM>, a bearing biasing element <NUM>, a spacer <NUM>, and an end cap <NUM>. Here, the spacer <NUM> is disposed between the bearings <NUM>. The bearing biasing element <NUM> biases the bearings <NUM> and the spacer <NUM> proximally toward the end cap <NUM>. The end cap <NUM> retains the bearings <NUM>, the spacer <NUM>, and the bearing biasing element <NUM> within the protective sheath bore <NUM>.

As shown in <FIG>, in this embodiment, a tag (e.g., a radio frequency identification tag RFID) is coupled to the end cap <NUM>, and a reader <NUM> is coupled to the connector member <NUM>. Here, data (e.g., calibration data, usage data, and the like) that is stored on the tag RFID may be read by the reader <NUM> to, among other things, ensure that the proper protective sheath assembly <NUM> is being utilized for the surgical procedure, determine the expected life of and/or determine replacement or service of the protective sheath assembly <NUM> after a predetermined amount of use, and the like. Data may also be written onto the tag RFID via the reader <NUM>, such as to update the tag RFID after a surgical procedure with a new expected life, number of cycles, duration of use, and the like. Here too as shown in <FIG>, other tags RFID and/or readers <NUM> may be employed to, among other things, identify the specific energy applicator <NUM> being utilized via calibration data. Other configurations are contemplated.

The embodiments of the systems <NUM> and tools <NUM> described herein afford significant advantages in connection with a broad number of medical and/or surgical procedures including, for example, where surgical manipulators <NUM> are employed. Specifically, it will be appreciated that the embodiments of the tool assembly <NUM> described and illustrated herein are configured such that the energy applicator <NUM> can be releasably attached in a simple, efficient, and reliable manner, and can be driven to manipulate patient <NUM> tissue in a number of different ways to accommodate different surgical procedures, user preference, and the like.

Claim 1:
A surgical tool assembly (<NUM>) for use with an energy applicator (<NUM>) to contact tissue of a patient at a surgical site, the energy applicator (<NUM>) having a shaft (<NUM>) extending along an axis (T) between a proximal end (<NUM>) and a distal end (<NUM>), the shaft (<NUM>) having an axial-force receiving surface (<NUM>, <NUM>), said tool assembly (<NUM>) comprising:
a support structure (<NUM>) to support said energy applicator (<NUM>);
an axial connector assembly (<NUM>) arranged to engage and releasably lock the energy applicator (<NUM>) to said support structure (<NUM>) in a locked state, wherein said axial connector assembly (<NUM>) comprises a cam member (<NUM>), a locking sleeve (<NUM>), and at least one engagement member (<NUM>);
a drive system (<NUM>; <NUM>, <NUM>) coupled to said support structure (<NUM>) to rotatably drive the shaft (<NUM>) of the energy applicator (<NUM>) about said axis (T);
a collet assembly (<NUM>) cooperating with said axial connector assembly (<NUM>) to apply a force to the axial-force receiving surface (<NUM>, <NUM>) of the energy applicator (<NUM>) when said axial connector assembly (<NUM>) engages and releasably locks the energy applicator (<NUM>) to said support structure (<NUM>) in said locked state; and
a reference surface (<NUM>) to be contacted by the energy applicator (<NUM>) in said locked state,
characterized in that
said force includes an axial component directing the energy applicator (<NUM>) proximally into continuous contact with said reference surface (<NUM>) in said locked state, wherein said at least one engagement member (<NUM>) is wedged between a sloped surface (<NUM>) of the cam member (<NUM>) and a sloped surface (<NUM>) of the axial-force receiving surface (<NUM>) of the shaft (<NUM>), each of the sloped surface (<NUM>) of the cam member (<NUM>) and the sloped surface (<NUM>) of the axial-force receiving surface (<NUM>) being arranged at an acute angle (α1, α2) relative to said axis (T), to apply said axial component of said force to the axial-force receiving surface (<NUM>, <NUM>) of the energy applicator (<NUM>) when said axial connector assembly (<NUM>) is in said locked state.