Patent Description:
Document <CIT> describes a set of removable cutting attachments of a surgical tool system. The attachments are of different lengths. Coupling members internal to the attachments are all spaced substantially identical distances from the distal ends of the attachments. This makes it possible to employ cutting accessories that have shafts of a common length in each attachment. The accessory shafts have plural, linearly aligned retention features formed on the shafts. This makes it possible to longitudinally adjust the position of the cutting accessory relative to the attachment with which the accessory is used.

A tool for use with a surgical robotic manipulator that comprises an energy applicator including a shaft extending along an axis between a proximal end and a distal end is known from document <CIT>. The shaft has an axial-force receiving surface. A 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 axis connector assembly and configured to apply a force to the axial-force receiving surface of the energy applicator 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 relates generally to a surgical handpiece system. An exemplary configuration provides a surgical handpiece system having a high-speed surgical bur assembly. The high-speed surgical bur assembly includes a nose tube defining a lumen extending between proximal and distal ends of the nose tube. The nose tube has a proximal portion extending along an axis. The proximal portion of the nose tube has an outer surface defining a nose tube recess. The nose tube also includes a projection disposed proximal to the nose tube recess. The high-speed surgical bur assembly also includes a driveshaft at least partially disposed within the lumen of the nose tube and configured to rotate relative to the nose tube. The high-speed surgical bur assembly also includes a cutting tool coupled to a distal region of the driveshaft. The cutting tool is configured to rotate with the driveshaft relative to the nose tube. The system also includes a surgical handpiece assembly including a hub having a bore defining a cavity for receiving the proximal portion of the nose tube of the high-speed surgical bur assembly. The surgical handpiece assembly also includes a biasing member disposed within the cavity of the hub. The biasing member is configured to be received by the nose tube recess of the nose tube to constrain a depth of the nose tube of the high-speed surgical bur assembly within the cavity of the hub relative to the hub. The surgical handpiece assembly also includes a radial alignment member disposed within the cavity of the hub proximal to the biasing member. The radial alignment member defines a notch for receiving the projection to constrain a radial orientation of the nose tube relative to the hub.

Another exemplary configuration provides a surgical handpiece system including a high-speed surgical bur assembly. The high-speed surgical bur assembly includes a nose tube defining a lumen extending between proximal and distal ends of the nose tube. The high-speed surgical bur assembly also includes a driveshaft at least partially disposed within the lumen of the nose tube and configured to rotate relative to the nose tube. The driveshaft has a proximal region extending along a driveshaft axis. The high-speed surgical bur assembly also includes a cutting tool coupled to a distal region of the driveshaft. The cutting tool is configured to rotate with the driveshaft relative to the nose tube. The system also includes a surgical handpiece assembly including a hub having a bore defining a cavity for receiving the proximal end of the nose tube of the high-speed surgical bur assembly and a proximal region of the driveshaft. The surgical handpiece assembly also includes a rotatable drive chuck configured to be rotated by a motor about a hub axis. The rotatable drive chuck is disposed within the cavity of the hub and configured to rotate relative to the hub. The rotatable drive chuck defines an opening for receiving the proximal region of the driveshaft. The rotatable drive chuck includes a driving portion disposed proximal the opening. The driving portion has at least two driving surfaces configured to engage the driveshaft in a driving orientation to rotate the driveshaft. The rotatable drive chuck also includes an aligning portion disposed between the driving portion and the opening of the rotatable drive chuck. The aligning portion has an alignment edge extending distally from the driving portion of the rotatable drive chuck toward the opening of the rotatable drive chuck. The alignment edge tapers away from the hub axis as the alignment edge extends distally from the driving portion of the rotatable drive chuck. The driveshaft is configured to engage the alignment edge of the aligning portion of the rotatable drive chuck to orient the driveshaft to the driving orientation for the driveshaft to engage the at least two driving surfaces of the driving portion of the rotatable drive chuck.

Claim <NUM> defines a high-speed surgical bur assembly configured to cut tissue and to be coupled to a surgical handpiece assembly. The high-speed surgical bur assembly includes a nose tube defining a lumen extending between proximal and distal ends of the nose tube. The nose tube has a proximal portion extending along an axis. The proximal portion of the nose tube has an outer surface defining a recess for receiving a biasing member of the surgical handpiece assembly to constrain a depth of the nose tube relative to the surgical handpiece assembly. The nose tube includes a projection disposed proximal to the recess. The projection is configured to constrain a radial orientation of the nose tube relative to the surgical handpiece assembly. The projection of the of the proximal portion of the nose tube extends proximally and generally parallel to the axis. The high-speed surgical bur assembly also includes a driveshaft at least partially disposed within the lumen of the nose tube and configured to rotate relative to the nose tube. The driveshaft has a drive portion at a proximal region of the driveshaft for engaging a rotatable drive chuck of the surgical handpiece assembly. The high-speed surgical bur assembly also includes a cutting tool coupled to a distal region of the driveshaft opposite the drive portion. The cutting tool is configured to rotate with the driveshaft relative to the nose tube in response to rotation of the rotatable drive chuck of the surgical handpiece assembly.

Another exemplary configuration provides a high-speed surgical bur assembly configured to cut tissue and to be coupled to a surgical handpiece assembly. The high-speed surgical bur assembly includes a nose tube defining a lumen extending between proximal and distal ends of the nose tube. The nose tube has a proximal portion configured to be coupled to the surgical handpiece assembly. The proximal portion of the nose tube includes a projection configured to constrain a radial orientation of the nose tube relative to the surgical handpiece assembly. The high-speed surgical bur assembly also includes a driveshaft at least partially disposed within the lumen of the nose tube and configured to rotate relative to the nose tube. The driveshaft has a proximal region extending along an axis. The proximal region of the driveshaft includes a drive portion for engaging a rotatable drive chuck of the surgical handpiece assembly in a driving orientation. The driveshaft also includes an alignment portion proximal the drive portion of the driveshaft. The alignment portion has an outer surface tapering toward the axis as the alignment portion extends from the drive portion to a proximal end of the driveshaft. The alignment portion is configured to engage the rotatable drive chuck to align the drive portion to the driving orientation for the drive portion of the driveshaft to engage the rotatable drive chuck. The alignment portion defines a notch extending distally from the proximal end of the driveshaft for mitigating contact between the alignment portion of the driveshaft and the rotatable drive chuck during engagement of the alignment portion with the rotatable drive chuck. The high-speed surgical bur assembly also includes a cutting tool coupled to a distal region of the driveshaft opposite the proximal region of the driveshaft. The cutting tool is configured to rotate with the driveshaft relative to the nose tube in response to rotation of the rotatable drive chuck of the surgical handpiece assembly.

Yet another exemplary configuration provides a high-speed surgical bur assembly for connection to a surgical handpiece assembly. The high-speed surgical bur assembly includes a driveshaft having proximal and distal ends. The high-speed surgical bur assembly also includes a nose tube having a first region defining a lumen to at least partially receive the driveshaft between the proximal and distal ends. The high-speed surgical bur assembly also includes a second region extending monolithically from the first region to couple the driveshaft to the surgical handpiece assembly at the proximal end. The second region includes an alignment feature configured to radially align the nose tube to the surgical handpiece assembly. The second region also includes a retention feature configured to axially retain the nose tube to the surgical handpiece assembly. The high-speed surgical bur assembly also includes a cutting tool coupled to the driveshaft at the distal end of the driveshaft.

Another exemplary configuration provides a surgical handpiece assembly configured to be coupled to a high-speed surgical bur assembly having a nose tube and a driveshaft rotatably coupled to the nose tube. The surgical handpiece assembly includes a hub having a bore defining a cavity for receiving a proximal portion of the nose tube. The surgical handpiece assembly also includes a biasing member disposed within the cavity of the hub. The biasing member is configured to engage the nose tube to constrain a depth of the nose tube within the cavity of the hub relative to the hub. The surgical handpiece assembly also includes a radial alignment member disposed within the cavity of the hub proximal to the biasing member. The radial alignment member defines a notch for receiving a projection of the nose tube to constrain a radial orientation of the nose tube relative to the hub. The radial alignment member has an alignment wall extending distally from the notch for engaging the projection of the nose tube and radially positioning the nose tube to permit the notch to receive the projection of the nose tube.

<FIG> depicts a perspective view of a surgical handpiece system <NUM>. The surgical handpiece system <NUM> includes a motor <NUM>, a hub <NUM> and a nose tube assembly <NUM>. The motor <NUM> connects to the hub <NUM>, and the nose tube assembly <NUM> connects to the motor <NUM> through the hub <NUM>. The nose tube assembly <NUM> includes a nose tube <NUM>, a driveshaft <NUM> (see <FIG>), and a cutting tool <NUM> coupled to the driveshaft <NUM>. The motor <NUM> is configured to provide torque through the hub <NUM> to the nose tube assembly <NUM>. Specifically, the motor <NUM> transfers torque through the hub <NUM> to the driveshaft <NUM> of the nose tube assembly <NUM> that rotates a cutting tool <NUM> of the nose tube assembly <NUM> disposed at a distal end <NUM> of the nose tube assembly <NUM>. The motor <NUM> is configured to transfer torque through the hub <NUM> and the nose tube assembly <NUM> to the cutting tool <NUM>. In some configurations, the motor <NUM> is configured to rotate the cutting tool <NUM> at speeds greater than <NUM>,<NUM> revolutions per minute. The high-speed torque transfer from the motor <NUM> to the cutting tool <NUM> allows the nose tube assembly <NUM> to accurately and efficiently abrade a nasal passage, for example. The nose tube assembly <NUM> may also be adapted for spinal, neuro, and endoscopic applications.

The hub <NUM> may include a variety of different configurations. The hub <NUM> may be straight, or curved depending on use. For example, in a curved configuration, the hub <NUM> may define a twenty-degree seamless curve away from a horizontal axis <NUM> of the hub <NUM>, or the hub <NUM> may define a straight length along the horizontal axis <NUM>. Additionally, the nose tube assembly <NUM> may also be curved or straight depending on application of the nose tube assembly <NUM>. More specifically, the nose tube <NUM> may be curved or straight. For example, the nose tube assembly <NUM> may include a bend at a proximal end <NUM>, or may include a bend at the distal end <NUM> of the nose tube assembly <NUM>. Transnasal applications of the nose tube assembly <NUM> may employ a bend at the distal end <NUM>, and spinal applications of the nose tube assembly <NUM> may employ a bend at the proximal end <NUM> of the nose tube assembly <NUM>. Bushings (not shown) align the driveshaft <NUM> within a lumen <NUM> (see <FIG>) of the nose tube <NUM> so that the driveshaft <NUM> does not contact an inner surface of the nose tube <NUM>. This allows the driveshaft <NUM> to rotate independently of the nose tube <NUM> when the motor <NUM> transfers torque through the driveshaft <NUM>.

Shown in <FIG> is a curved hub <NUM>. The curved hub <NUM> differs from the straight hub based on the desired surgical application of the surgical handpiece system <NUM>. As noted above, the degree to which the hub <NUM> and/or the nose tube assembly <NUM> may be bent may be influenced by surgical application. It is contemplated that the hub <NUM> and/or the nose tube assembly <NUM> may be straight and not employ any bends. Specifically, the curved hub <NUM> may include a plurality of ball bearings (not shown) or other torque transfer mechanisms used to support rotatable components that allow the curved hub <NUM> to transfer torque to the nose tube assembly <NUM>. The bearings provide alignment of shafts (not shown) interconnected by a gear set (not shown) to transfer torque from the motor <NUM> through the hub <NUM> and to the nose tube assembly <NUM>.

As stated above, the hub <NUM> attaches to the motor <NUM>. The hub <NUM> may include features that aid in aligning and locking the hub <NUM> to the motor <NUM> of the surgical handpiece system <NUM>. For example, the hub <NUM> may include a visual indicator such as a dot (not shown) that corresponds to another dot (not shown) on the motor <NUM> such that alignment between the dots allows the hub <NUM> to couple to the motor <NUM>. Additionally, the hub <NUM> may include an anti-rotation pin (not shown) at the proximal end <NUM> of the hub <NUM> to allow specific orientations between the hub <NUM> and the motor <NUM>. An external c-clip (not shown) as well as an O-ring (not shown) may further aid to establish a secure connection between the hub <NUM> and the motor <NUM> such that the motor <NUM> transfers torque through the hub <NUM> to the nose tube assembly <NUM>. The hub <NUM> may also include a knurled portion (not shown). The knurled portion corresponds to a position on the hub <NUM> where an operator may place a finger to hold the surgical handpiece system <NUM>.

<FIG> depicts a cross-sectional view of the surgical handpiece system <NUM> taken along lines <NUM>-<NUM> in <FIG>. Specifically, <FIG> shows a cross-section of the nose tube assembly <NUM> and the hub <NUM>. The motor <NUM> is not shown in <FIG>. The nose tube assembly <NUM> is shown having the driveshaft <NUM> extending through the lumen <NUM> defined in the nose tube <NUM>. The driveshaft <NUM> extends into the hub <NUM> and the hub <NUM> is configured to transfer torque from the motor <NUM> to the driveshaft <NUM>. The driveshaft <NUM> is shown as extending between and beyond the proximal and distal ends <NUM>, <NUM> of the nose tube assembly <NUM>.

As shown in <FIG>, the driveshaft <NUM> is at least partially disposed within the lumen <NUM>. The driveshaft <NUM> also includes an alignment portion <NUM>. The alignment portion <NUM> is configured to align a drive portion <NUM> of the driveshaft <NUM> into an orientation to engage a rotatable drive chuck <NUM> disposed within the hub <NUM>. The rotatable drive chuck <NUM> is placed into alignment with the driveshaft <NUM> of the nose tube assembly <NUM> with the hub <NUM> to transfer torque through the driveshaft <NUM> from the motor <NUM>. As will be described in more detail below, the alignment portion <NUM> of the driveshaft <NUM> is disposed at the proximal end <NUM> of the nose tube assembly <NUM>. To align the driveshaft <NUM> with the hub <NUM>, the rotatable drive chuck <NUM> engages a leading edge <NUM> of the alignment portion <NUM> of the driveshaft <NUM> as the nose tube assembly <NUM> is urged towards the hub <NUM>. Specifically, the alignment portion <NUM> defines one or more leading edges <NUM> to engage one or more ramped surfaces <NUM> of the rotatable drive chuck <NUM> to align the drive portion <NUM> of the driveshaft <NUM> in the rotatable drive chuck <NUM>. As described in more detail further below, the configuration of the ramped surfaces <NUM> of the rotatable drive chuck <NUM> and the leading edges <NUM> of the alignment portion <NUM> permits the driveshaft <NUM> to be self-aligning. Said differently, when the nose tube assembly <NUM> is urged toward the hub <NUM>, the leading edge <NUM> of the alignment portion <NUM> engages the ramped surface of the rotatable drive chuck <NUM> to rotate the driveshaft <NUM>. This engagement and continued urging of the nose tube assembly <NUM> toward the hub <NUM> will rotate the driveshaft <NUM> to an orientation where the drive portion <NUM> engages the rotatable drive chuck <NUM> to permit torque transfer between the driveshaft <NUM> and the rotatable drive chuck <NUM>. Regardless of the initial radial orientation of the alignment portion <NUM>, the configuration of the ramped surfaces <NUM> of the rotatable drive chuck <NUM> and the leading edges <NUM> of the alignment portion <NUM> will ensure that the drive portion <NUM> of the driveshaft <NUM> is in the orientation to engage the rotatable drive chuck <NUM> when the nose tube assembly <NUM> is urged toward the hub <NUM>. The self-aligning feature is beneficial in certain embodiments because the driveshaft <NUM> is not visible when the nose tube assembly <NUM> is coupled to the hub <NUM> and because the driveshaft <NUM> is not axially movable within the nose tube assembly <NUM>. Thus, a user grasps the outer surface of the nose tube <NUM> and urges it towards the hub <NUM>. Through axial movement alone, the engagement between the alignment portion <NUM> of the driveshaft <NUM> and the rotatable drive chuck <NUM> results in rotation of the driveshaft <NUM> without requiring the user to spin the cutting tool <NUM> of the nose tube assembly <NUM> to obtain a proper orientation of the drive portion <NUM> to the rotatable drive chuck <NUM>.

Proper alignment between the hub <NUM> and the driveshaft <NUM> may be indicated by tactile feedback. More specifically, when the leading edge <NUM> of the alignment portion <NUM> engages the ramped surface <NUM> of the rotatable drive chuck <NUM>, haptic feedback such as, for example, vibrations from contact between the leading edge <NUM> and the ramped surface <NUM>, may be felt through the surgical handpiece system <NUM>. The haptic feedback may be indicative of proper alignment between the nose tube assembly <NUM>, the hub <NUM>, and the motor <NUM>.

As shown in <FIG>, once aligned to a proper orientation, the drive portion <NUM> of the driveshaft <NUM> mates with flat surfaces <NUM> within a drive chamber <NUM> of the rotatable drive chuck <NUM>. This allows torque to transfer from the motor <NUM> through the hub <NUM> to the driveshaft <NUM>. Stated differently, the motor <NUM> transfers torque through the hub <NUM> once the drive portion <NUM> aligns with the flat surface <NUM> in the drive chamber <NUM> of the rotatable drive chuck <NUM>, in which the rotatable drive chuck <NUM> rotates independently from the hub <NUM>. Bearings <NUM> disposed within the hub <NUM> aid to align the driveshaft <NUM> and rotatable drive chuck <NUM> along the horizontal axis <NUM> of the surgical handpiece system <NUM>. Therefore, the bearings <NUM> allow for efficient torque transfer along the horizontal axis <NUM> by aligning the rotatable drive chuck <NUM> and driveshaft <NUM> within the hub <NUM>, and nose tube assembly <NUM>, respectively.

<FIG> depicts a partial, cross-sectional view of the driveshaft <NUM> disposed within the hub <NUM> taken along lines <NUM>-<NUM> shown in <FIG>. Specifically, <FIG> depicts the drive portion <NUM> of the driveshaft <NUM> aligned within the drive chamber <NUM> of the rotatable drive chuck <NUM>. Bearings <NUM> are shown engaging the driveshaft <NUM> and rotatable drive chuck <NUM> to align the driveshaft <NUM> and rotatable drive chuck <NUM> along the horizontal axis <NUM>, and allow the driveshaft <NUM> and rotatable drive chuck <NUM> to rotate independently of the hub <NUM>. Independent rotation of the driveshaft <NUM> and rotatable drive chuck <NUM> relative to the hub <NUM> allows the motor <NUM> to transfer torque through the hub <NUM> to the cutting tool <NUM>, such as a bur.

Referring again to <FIG>, the nose tube <NUM> of the nose tube assembly <NUM> defines a recess <NUM> disposed at the proximal end <NUM> of the nose tube <NUM>, and adjacent the bearings <NUM> when the nose tube assembly <NUM> is coupled to the hub <NUM>. Specifically, the nose tube <NUM> has an outer surface <NUM> that defines the recess <NUM> for receiving a biasing member <NUM>, such as a c-clip, to constrain a depth of the nose tube assembly <NUM> relative to the surgical handpiece system <NUM>. The biasing member <NUM> is held axially in place using the hub <NUM>. When the nose tube assembly <NUM> is inserted into the hub <NUM>, the biasing member <NUM> expands as the nose tube assembly <NUM> is inserted such that the biasing member <NUM> then seats within the recess <NUM> when the nose tube assembly <NUM> is fully inserted into the hub <NUM>.

The biasing member <NUM> is disposed in the recess <NUM> to hold the nose tube assembly <NUM> in place along the horizontal axis <NUM> during use of the surgical handpiece system <NUM>. The recess <NUM>, therefore, may also be referred to as a retention feature <NUM>, in which the biasing member <NUM> is disposed in the retention feature <NUM> to maintain axial alignment of the nose tube assembly <NUM> and the driveshaft <NUM> relative to the hub <NUM> during use of the surgical handpiece system <NUM>. In other words, as the nose tube assembly <NUM> is pushed into the hub <NUM>, the biasing member <NUM> is opened and grabs onto the recess <NUM>. The biasing member <NUM> may be referred to as a retention element as the biasing member <NUM> serves to retain the depth of the nose tube assembly <NUM> relative to the hub <NUM> by engaging the retention feature. The biasing member <NUM> prevents axial movement of nose tube assembly <NUM> relative to the hub <NUM>. More specifically, the biasing member <NUM> prevents the nose tube assembly <NUM> from inadvertently separating from the hub <NUM> when the biasing member <NUM> engages the recess <NUM>. The engagement between the biasing member <NUM> and the recess <NUM> may be overcome in response to the user applying a force (e.g., by pulling) sufficient to expand the biasing member <NUM> out of the recess <NUM> to separate the nose tube assembly <NUM> from the hub <NUM>.

As described above, the biasing member <NUM> aids to constrain the nose tube assembly <NUM> along the horizontal axis <NUM> relative to the hub <NUM>. As shown in <FIG>, the recess <NUM> may define a beveled edge <NUM> that may be positioned adjacent to a projection <NUM> of the nose tube <NUM> extending radially away from the lumen <NUM> of the nose tube <NUM> such that the biasing member <NUM> abuts the projection <NUM>. The beveled edge <NUM> of the recess <NUM> may reduce the force required by the user to remove the nose tube assembly <NUM> from the hub <NUM>.

As shown in <FIG>, the driveshaft <NUM> includes a retention portion <NUM> disposed distal the alignment portion <NUM> and the drive portion <NUM> of the driveshaft <NUM>. The retention portion <NUM> of the driveshaft <NUM> may be disposed within the lumen <NUM> of the nose tube <NUM>. Specifically, the retention portion <NUM> is configured to extend partially into the nose tube assembly <NUM> and abut a shelf <NUM> of the internal surface of the nose tube <NUM> defining the lumen <NUM> to constrain the driveshaft <NUM> relative to the nose tube <NUM>. In some configurations, such as one illustrated in <FIG>, a bearing may be interposed between the shelf <NUM> and the retention portion <NUM> of the driveshaft <NUM>. The retention portion <NUM> defines a diameter <NUM> being greater than a diameter <NUM> of the lumen <NUM> to allow the retention portion <NUM> to constrain the driveshaft <NUM> relative to the nose tube assembly <NUM>. This configuration prevents the driveshaft <NUM> from being removed axially from the nose tube <NUM> in a distal direction. In one configuration, the relative diameter of the cutting tool <NUM> in relation to the lumen <NUM> and/or a distal bushing <NUM> (see <FIG>) coupled to the distal end <NUM> of the nose tube <NUM> prevents the driveshaft <NUM> from being removed axially from the nose tube <NUM> in a proximal direction.

Referring to <FIG>, partial, perspective views of the nose tube assembly <NUM> and the rotatable drive chuck <NUM> are shown. <FIG> depicts a partial, perspective, exploded view of the nose tube assembly <NUM> and the hub <NUM> of the surgical handpiece system <NUM>. <FIG> is shown as exploded along the horizontal axis <NUM>, in which the nose tube assembly <NUM> and the hub <NUM> are spaced along the horizontal axis <NUM>. Specifically, <FIG> depicts an exploded, perspective view of the nose tube assembly <NUM> having the projection <NUM> that extends radially from the surface <NUM>. <FIG> depicts a partial perspective view of the nose tube assembly <NUM> detached from the hub <NUM>. <FIG> depicts a partial perspective view of the nose tube assembly <NUM> defining the recess <NUM> and the projection <NUM> on the surface <NUM> and the rotatable drive chuck <NUM>.

Referring to <FIG>, the hub <NUM> has a proximal end <NUM> and a distal end <NUM> opposite the proximal end <NUM>. The hub <NUM> has an internal surface defining a bore <NUM> extending from the distal end <NUM> to the proximal end <NUM>. The internal surface also defines a channel <NUM> in communication with the bore <NUM> extending from the distal end <NUM> toward the proximal end <NUM>. The projection <NUM> of the nose tube <NUM> is adapted to radially align the nose tube <NUM> during insertion of the nose tube assembly <NUM> into the bore <NUM> of the hub <NUM>. In this way, the projection <NUM> acts as a radial alignment feature <NUM> of the nose tube <NUM>. Stated differently, the projection <NUM> acts as a keyed, alignment feature <NUM>, in which the projection <NUM> fits into the channel <NUM> defined in the hub <NUM>. The channel <NUM> is sized to accommodate the projection <NUM> such that radial movement of the nose tube <NUM> when the channel <NUM> receives the projection <NUM> is mitigated. Mitigation of this radial movement permits the nose tube assembly <NUM> to couple to the hub <NUM> with precision. In this way, the projection <NUM> slides within the channel <NUM> to radially align the nose tube <NUM> relative to the hub <NUM>. There may be two channels <NUM> and two projections <NUM>, the channels <NUM> and projections <NUM> diametrically spaced from one another across the longitudinal axis. In another configuration, there may be two channels <NUM> and one projection <NUM> such that the hub <NUM> permits the nose tube assembly <NUM> to be coupled to the hub <NUM> in two different orientations. Such a configuration may be advantageous when the hub <NUM> and/or the nose tube assembly <NUM> employs a bend as described above.

As stated, the projection <NUM> extends radially from the nose tube <NUM>. Specifically, the projection <NUM> extends vertically from a surface <NUM> of the nose tube <NUM>. Extending from the surface <NUM> of the nose tube <NUM> allows the projection <NUM> to engage the channel <NUM> defined in the hub <NUM> such that radial movement of the projection <NUM> in the channel <NUM>, for example, from rotating the nose tube <NUM> relative to the hub <NUM>, is prevented. The engagement of the projection <NUM> in the channel <NUM> also serves to grossly align the drive portion <NUM> of the driveshaft <NUM> in the drive chamber <NUM> of the rotatable drive chuck <NUM>. In this way, the projection <NUM> provides efficient and accurate alignment.

The projection <NUM> extends from the surface <NUM> of the nose tube <NUM> to a peak <NUM>. The peak <NUM> defines a height of the projection <NUM>. The height of the projection <NUM> may be based on dimensions of the hub <NUM>. The peak <NUM> of the projection <NUM> may be formed from at least one, first, slanted surface <NUM>. As will be described in more detail, the projection <NUM> may also be formed from two, first and second, slanted surfaces <NUM>, <NUM>. The peak <NUM> may extend from the first slanted surface <NUM> to the second slanted surface <NUM>.

The first slanted surface <NUM> may extend from the beveled edge <NUM> of the recess <NUM> to the peak <NUM> of the projection <NUM>. The second slanted surface <NUM> may be disposed along the alignment portion <NUM> of the driveshaft <NUM>, and extend to the peak <NUM> of the projection <NUM>. The first and second slanted surfaces <NUM>, <NUM> may also define opposite inclinations such that the first and second slanted surfaces <NUM>, <NUM> culminate at the peak <NUM> of the projection <NUM>. Angles that form the inclination of the first and second slanted surfaces <NUM>, <NUM> may vary, or be equal based on an optimal extension and operation of the projection <NUM> as the projection <NUM> slides in the channel <NUM>. Stated differently, the peak <NUM> may extend between the first and second slanted surfaces <NUM>, <NUM> to interconnect the first and second surfaces <NUM>, <NUM>, which defines the height of the projection <NUM>. The first and second slanted surfaces <NUM>, <NUM> also aid to allow the projection <NUM> to slide into the channel <NUM> in the hub <NUM>. The first and second slanted surfaces <NUM>, <NUM> provide ease of assembly by reducing frictional forces as the projection <NUM> slides through the channel <NUM>. Additionally, the peak <NUM> may define a radius between the first and second slanted surfaces <NUM>, <NUM>. For example, the peak <NUM> may be rounded between the first and second slanted surfaces <NUM>, <NUM>. The radius of the peak <NUM> may be determined based on optimal sliding parameters of the projection <NUM> in the channel <NUM>. Therefore, the radius of the peak <NUM> may be formed to fit within the channel <NUM> defined in the hub <NUM>. Other shapes of the projection <NUM> are also contemplated.

As previously described, the projection <NUM> is disposed adjacent to the recess <NUM>. Specifically, in certain configurations, the first slanted surface <NUM> is formed proximate the beveled edge <NUM> of the recess <NUM>. Both the retention (shown as the recess) and radial alignment features (shown as the projection) <NUM>, <NUM> of the nose tube assembly <NUM> may be disposed adjacent to each other. Since the projection <NUM> is disposed adjacent the recess <NUM>, the biasing member <NUM> abuts the projection <NUM> on the nose tube <NUM> when the nose tube assembly <NUM> is coupled to the hub <NUM>. To maintain alignment during insertion, the projection <NUM> defines the height of the peak <NUM> relative to the horizontal axis 20and the recess <NUM> defines a distance to the horizontal axis <NUM> being less than the height of the peak <NUM>. The height of the peak <NUM> being greater than the distance from the biasing member <NUM> to the horizontal axis <NUM> allows the projection <NUM> to adequately engage and slide in the channel <NUM> formed in the hub <NUM>.

In another configuration, if the recess <NUM> defined the distance from the horizontal axis <NUM> as being greater than the height of the peak <NUM>, the peak <NUM> may not engage the channel <NUM>, and rotational misalignment between the nose tube <NUM> and the hub <NUM> may be introduced during use of the surgical handpiece system <NUM>. Therefore, the distance from the recess <NUM> to the horizontal axis <NUM> being less than the height of the peak <NUM> allows the projection <NUM> to maintain rotational alignment between the nose tube <NUM> and the hub <NUM> during use of the surgical handpiece system <NUM>, while subsequently allowing the retention feature <NUM> to maintain axial alignment of the nose tube assembly <NUM>, and hence the driveshaft <NUM>, with the features of the hub <NUM>.

It may be useful to understand the nose tube <NUM> in terms of a first region <NUM> and a second region <NUM> (see <FIG>). The first region <NUM> may represent the majority of the length of the nose tube <NUM>, while the second region <NUM> may be the portion of the nose tube <NUM> that interacts with the hub <NUM>. In certain configurations, the first region <NUM> and second region <NUM> may both be formed from a metallic material, such as stainless steel. The second region <NUM> may extend monolithically from the first region <NUM> from a single piece of metal stock. In other words, the nose tube <NUM>, including both the first region <NUM> and the second region <NUM> may be formed from a single piece of metal stock. The second region <NUM> may include the radial alignment feature <NUM> and an axial retention feature <NUM> to axially retain the nose tube assembly <NUM> in the surgical handpiece system <NUM>. The alignment and retention features <NUM>, <NUM> may be formed from the metallic material that forms the first and second regions <NUM>, <NUM>, and hence the alignment features <NUM> and the retention features <NUM> may be machined from the same piece of metal stock that is used to machine the first region <NUM> of the nose tube <NUM>.

Referring to <FIG> and <FIG>, the proximal portion of the driveshaft <NUM> is shown. <FIG> depicts a perspective view of the alignment portion <NUM> including the leading edge <NUM>, the retaining portion <NUM>, and the drive portion <NUM>. <FIG> depicts a front view of the proximal portion of the driveshaft <NUM>. Specifically, <FIG> depicts a front view of the alignment portion <NUM> of the driveshaft <NUM>.

In one exemplary configuration of assembly, a user grasps the nose tube <NUM> of the nose tube assembly <NUM>. The user partially inserts the nose tube assembly <NUM> within the bore <NUM> of the hub <NUM>. Then the user aligns the projection <NUM> of the nose tube <NUM> with the channel <NUM> of the hub <NUM> and continues to urge the nose tube assembly <NUM> toward the hub <NUM>. The engagement between the projection <NUM> and the channel <NUM> radially aligns the nose tube <NUM> to the hub <NUM>. When the proximal end of the nose tube <NUM> abuts the biasing member <NUM>, the biasing member <NUM> expands to accommodate the nose tube <NUM>. Continued urging of the nose tube assembly <NUM> toward the hub <NUM> results in the biasing member <NUM> being received by the recess <NUM> of the nose tube <NUM>. When the recess <NUM> receives the biasing member <NUM>, the nose tube <NUM> and the rest of the nose tube assembly <NUM> are axially retained relative to the hub <NUM>.

Before the recess <NUM> receives the biasing member <NUM>, the leading edge <NUM> of the alignment portion <NUM> of the driveshaft <NUM> abuts the ramped surface <NUM> of the rotatable drive chuck <NUM> to cam the driveshaft <NUM>, and thus the drive portion <NUM> of the driveshaft <NUM>, toward the orientation where the drive portion <NUM> of the driveshaft <NUM> engages the rotatable drive chuck <NUM>. When the recess <NUM> receives the biasing member <NUM>, the driveshaft <NUM> has been cammed into the orientation with the drive portion <NUM> received in the drive chamber <NUM> of the rotatable drive chuck <NUM> and the drive portion <NUM> abutting the flat surface <NUM> of the rotatable drive chuck <NUM> to receive torque from and rotate with the rotatable drive chuck <NUM>. Depending on an initial radial orientation of the driveshaft <NUM> when the nose tube assembly <NUM> is first introduced into the hub <NUM> (i.e., before camming), the leading edge <NUM> of the alignment portion <NUM> may first contact the ramped surface <NUM> of the rotatable drive chuck <NUM> at different axial positions of the nose tube <NUM> relative to the hub <NUM>. It is contemplated that where the initial radial orientation of the driveshaft <NUM> is already in the orientation required for the drive portion <NUM> of the driveshaft <NUM> to be received in the drive chamber <NUM> and engage the rotatable drive chuck <NUM>, the leading edge <NUM> of the alignment portion <NUM> would not contact the ramped surface <NUM> of the rotatable drive chuck <NUM>.

The axial position of the driveshaft <NUM> relative to the rotatable drive chuck <NUM> is maintained by the axial retention of the nose tube <NUM> to the hub <NUM> via the biasing member <NUM> and the recess <NUM>. In other words, because the driveshaft <NUM> is axially retained relative to the nose tube <NUM>, the axial position of the driveshaft <NUM> relative to the hub <NUM> and rotatable drive chuck <NUM> is tied to the axial position of the nose tube <NUM> relative to the hub <NUM> and the rotatable drive chuck <NUM>. The nose tube <NUM> is retained by the biasing member <NUM> until the user pulls the nose tube assembly <NUM> relative to the hub <NUM> with sufficient force to overcome the biasing member <NUM> by expanding the biasing member <NUM>.

As previously described, the alignment portion <NUM> of the driveshaft <NUM> defines the leading edge <NUM> that aids to align the drive portion <NUM> of the driveshaft <NUM> in the drive chamber <NUM> of the rotatable drive chuck <NUM>. When the nose tube assembly <NUM> is inserted into the bore <NUM> of the hub <NUM>, the leading edge <NUM> engages the ramped surface <NUM> of the drive chamber <NUM> in the rotatable drive chuck <NUM> to align the drive portion <NUM> of the driveshaft <NUM> in the drive chamber <NUM> of the rotatable drive chuck <NUM>. The leading edge <NUM> engages the ramped surface <NUM> to translate an insertion force into a rotational force to provide alignment between the drive portion <NUM> of the driveshaft <NUM> and the rotatable drive chuck <NUM>. While described as a single leading edge <NUM>, the alignment portion <NUM> of the driveshaft <NUM> may include one or more leading edges <NUM>.

<FIG> depicts the leading edges <NUM> as being defined between at least two curved surfaces <NUM> defined on the alignment portion <NUM> of the driveshaft <NUM>. The curved surfaces <NUM> that interconnect to define the leading edges <NUM>. The leading edges may be asymmetrical across the horizontal axis <NUM>. The curved surfaces <NUM> connect to form a tip <NUM> of the alignment portion <NUM>. The tip <NUM>, as shown in <FIG> and <FIG>, resembles a parallelogram. As described previously, the rotatable drive chuck <NUM> rotates independently of the hub <NUM>. Upon insertion of the projection <NUM> into the channel <NUM>, the alignment portion <NUM> engages the ramped surface <NUM> of the rotatable drive chuck <NUM> to alignment the drive portion <NUM> in the drive chamber <NUM>. Specifically, the leading edge <NUM> contacts the ramped surface <NUM> to cause a cam rotation of the driveshaft <NUM> to ensure proper alignment of the drive portion <NUM> in the drive chamber <NUM>. Therefore, the leading edges <NUM> further aid to align the drive portion <NUM> of the driveshaft <NUM> with the flat surface <NUM> in the drive chamber <NUM> to accurately transfer torque from the motor <NUM> to the cutting tool <NUM> disposed at the distal end <NUM> of the nose tube assembly <NUM>.

Referring to <FIG>, another configuration of the surgical handpiece system <NUM> is illustrated. It should be appreciated that the configuration of the surgical handpiece system <NUM> described above may include similar elements to the surgical handpiece system <NUM> described below and vice versa.

As shown in <FIG>, the surgical handpiece system <NUM> comprises a high-speed surgical bur assembly <NUM> (<FIG>) and a surgical handpiece assembly <NUM> (<FIG>). Similarly to the configuration of the surgical handpiece system <NUM> shown in <FIG>, the surgical handpiece system <NUM> may also comprise a motor (not shown) configured to be coupled to the surgical handpiece assembly <NUM> to provide torque to the surgical handpiece system <NUM>.

Referring to <FIG>, a cross-section of one configuration of the high-speed surgical bur assembly <NUM> is illustrated. The high-speed surgical bur assembly <NUM> comprises a nose tube <NUM>. The nose tube <NUM> defines a lumen extending between a proximal end and a distal end of the nose tube <NUM>. At least a proximal portion <NUM> of the nose tube <NUM> extends along an axis AX. The nose tube <NUM> may include a bend such as a distal bend of the nose tube <NUM> illustrated in <FIG> rather than extend axially along an entire length of the nose tube <NUM>. The bend may assist a user in positioning the distal end of the nose tube <NUM> in certain advantageous positions during surgery.

The high-speed surgical bur assembly <NUM> further comprises a driveshaft <NUM> that is at least partially disposed within the lumen of the nose tube <NUM>. The driveshaft <NUM> is configured to rotate relative to the nose tube <NUM>. A proximal region <NUM> of the driveshaft <NUM> is configured to engage the surgical handpiece assembly <NUM> as described in greater detail further below. The high-speed surgical bur assembly <NUM> further comprises a cutting tool <NUM> that is coupled to a distal region of the driveshaft <NUM>. The cutting tool <NUM> is configured to rotate with the driveshaft <NUM> relative to the nose tube <NUM>. In one configuration, the cutting tool <NUM> is a bur. In other configurations, the cutting tool <NUM> comprises another rotary tool configured to abrade tissue.

The high-speed surgical bur assembly <NUM> may comprise bushings <NUM>, <NUM>, <NUM> for facilitating relative rotation between the driveshaft <NUM> and the nose tube <NUM>. A proximal bushing <NUM> may be coupled to the nose tube <NUM> and disposed at least partially within the lumen of the nose tube <NUM> and around the driveshaft <NUM>. A distal bushing <NUM> may be coupled to the nose tube <NUM> and disposed at least partially within the lumen of the nose tube <NUM> and around the driveshaft <NUM>. A middle bushing <NUM> may be disposed within the lumen between the proximal and distal bushings <NUM>, <NUM> to prevent contact between the driveshaft <NUM> and the nose tube <NUM> within the lumen of the nose tube <NUM>. In one configuration, the middle bushing <NUM> is fixed to the nose tube <NUM>. In another configuration, the proximal and distal bushings <NUM>, <NUM> retain the middle bushing <NUM> within the lumen of the nose tube <NUM>. In other configurations the middle bushing <NUM> is retained in the lumen of the nose tube <NUM> by the bend in the nose tube <NUM> and corresponding bend of the middle bushing <NUM>. The proximal and distal bushings <NUM>, <NUM> may also serve as retention features for coupling the driveshaft <NUM> to the nose tube <NUM>. In one configuration, the proximal region <NUM> of the driveshaft <NUM> comprises a retention portion <NUM> proximal to the proximal bushing <NUM>. The retention portion <NUM> of the proximal region <NUM> of the driveshaft <NUM> has an outer diameter greater than an inner diameter of the proximal bushing <NUM> to prevent movement of the driveshaft <NUM> in a distal direction relative to the nose tube <NUM>. The cutting tool <NUM> may have an outer diameter greater than an inner diameter of the distal bushing <NUM> to prevent movement of the driveshaft <NUM> in a proximal direction relative to the nose tube <NUM>. In other configurations, the driveshaft <NUM> is coupled to the nose tube <NUM> in another manner to permit relative rotation between the driveshaft <NUM> and the nose tube <NUM> and prevent axial movement between the driveshaft <NUM> and the nose tube <NUM>.

Referring to <FIG>, the proximal portion <NUM> of the nose tube <NUM> has an outer surface. The outer surface may define a recess <NUM> for engaging the surgical handpiece assembly <NUM> to constrain a depth of the nose tube <NUM> relative to the surgical handpiece assembly <NUM>. The outer surface of the proximal portion <NUM> of the nose tube <NUM> may have a proximal shoulder <NUM> that defines a proximal end of the recess <NUM> and a distal shoulder <NUM> that defines a distal end of the recess <NUM>. Either or both proximal and distal shoulders <NUM>, <NUM> may be tapered. The nose tube <NUM> comprises a projection <NUM> disposed proximal to the recess <NUM>. The projection <NUM> is configured to constrain a radial orientation of the nose tube <NUM> relative to the surgical handpiece assembly <NUM>. The projection <NUM> extends proximally and generally parallel to the axis AX. The proximal end of the projection <NUM> may comprise a rounded surface <NUM>. The projection <NUM> of the proximal portion <NUM> of the nose tube <NUM> may include a flat surface <NUM> that is parallel to the axis AX of the proximal portion <NUM> of the nose tube <NUM>. The rounded and flat surfaces <NUM>, <NUM> of the projection <NUM> may assist engagement between the nose tube <NUM> and the surgical handpiece assembly <NUM>. Engagement between the nose tube <NUM> and the surgical handpiece assembly <NUM> is discussed in greater detail further below. In the configuration illustrated in <FIG>, the nose tube <NUM> comprises two projections <NUM> to constrain the radial orientation of the nose tube <NUM> relative to the surgical handpiece assembly <NUM>. It is contemplated that a single projection <NUM> may be used instead to constrain the radial orientation of the nose tube <NUM> relative to the surgical handpiece assembly <NUM>. It is also contemplated that three or more projections <NUM> may be employed to constrain the radial orientation of the nose tube <NUM> relative to the surgical handpiece assembly <NUM>.

Referring to <FIG>, the proximal region <NUM> of the driveshaft <NUM> is rotatable about the axis AX of the proximal portion <NUM> of the nose tube <NUM>. The proximal region <NUM> of the driveshaft <NUM> comprises a drive portion <NUM> proximal to the retention portion <NUM> for engaging the surgical handpiece assembly <NUM> in a driving orientation. The drive portion <NUM> may comprise two or more drive surfaces <NUM> for engaging the surgical handpiece assembly <NUM>. The drive surfaces <NUM> may be flat and parallel to the axis AX.

The proximal region <NUM> of the driveshaft <NUM> may also comprise an alignment portion <NUM> proximal to the drive portion <NUM> of the driveshaft <NUM>. The alignment portion <NUM> has an outer surface tapering toward the axis AX as the alignment portion <NUM> extends from the drive portion <NUM> to a proximal end of the driveshaft <NUM>. The alignment portion <NUM> is configured to engage the surgical handpiece assembly <NUM> to align the drive portion <NUM> to the driving orientation. In the configuration illustrated in <FIG>, the alignment portion <NUM> comprises a proximal edge <NUM> adjacent the proximal end of the proximal region <NUM> of the driveshaft <NUM> to engage the surgical handpiece assembly <NUM>. In other configurations, the alignment portion <NUM> may comprise a flat or rounded surface instead of the proximal edge <NUM>. The alignment portion <NUM> may define a notch <NUM> extending distally from the proximal end of the driveshaft <NUM> for mitigating contact between the alignment portion <NUM> of the driveshaft <NUM> and the surgical handpiece assembly <NUM> during engagement. Mitigating the amount of contact during engagement may reduce potential jamming during engagement resulting from multiple points of contact. In other configurations, the alignment portion <NUM> may not define the notch <NUM>.

In the configuration illustrated in <FIG>, the proximal region <NUM> of the driveshaft <NUM> is disposed outside of the lumen of the nose tube <NUM> and proximal the proximal portion <NUM> of the nose tube <NUM>. In other configurations, the proximal region <NUM> of the driveshaft <NUM> may be disposed at least partially within the lumen of the nose tube <NUM> or distal the proximal portion <NUM> of the nose tube <NUM>. Engagement between the proximal region <NUM> of the driveshaft <NUM> and the surgical handpiece assembly <NUM> is discussed in greater detail further below.

In another configuration illustrated in <FIG>, the alignment portion <NUM> of the driveshaft <NUM> may comprise a proximal surface <NUM> disposed proximally of the proximal edge <NUM> to prevent the proximal edge <NUM> from engaging the rotatable drive chuck <NUM> of the surgical handpiece assembly <NUM> after the drive portion <NUM> is aligned in the driving orientation. The proximal surface <NUM> may comprise a planar surface perpendicular to the axis AX. In other configurations, the proximal surface <NUM> may comprise a rounded surface.

Referring to <FIG> and <FIG>, the surgical handpiece assembly <NUM> comprises a hub <NUM>. The hub <NUM> has a bore <NUM> defining a cavity <NUM> for receiving at least part of the high-speed surgical bur assembly <NUM>. Specifically, the cavity <NUM> is configured to receive at least the proximal portion <NUM> of the nose tube <NUM> and the proximal region <NUM> of the driveshaft <NUM> of the high-speed surgical bur assembly <NUM>. A proximal portion of the hub <NUM> may be configured to be coupled to a motor housing (not shown) that includes a motor, similar of the motor <NUM> coupling to the hub <NUM> in the configuration illustrated in <FIG>.

The surgical handpiece assembly <NUM> further comprises a biasing member <NUM> disposed within the cavity <NUM> of the hub <NUM>. The biasing member <NUM> may be a C-clip. The bore <NUM> of the hub <NUM> may define a recess <NUM> in communication with the cavity <NUM>. The recess <NUM> defined by bore <NUM> of the hub <NUM> is configured to receive the biasing member <NUM>. The bore <NUM> of the hub <NUM> may have a distal shoulder <NUM> that defines a distal end of the recess <NUM> in the hub <NUM>. The distal shoulder <NUM> retains the biasing member <NUM> from exiting the recess <NUM> of the hub <NUM> in a distal direction. When the high-speed surgical bur assembly <NUM> is received by the cavity <NUM> of the hub <NUM> of the surgical handpiece assembly <NUM>, the biasing member <NUM> is received by the recess <NUM> of the nose tube <NUM>. The biasing member <NUM> may be configured to engage one or both the proximal and distal shoulders <NUM>, <NUM> of the recess <NUM> of the nose tube <NUM> to constrain a depth of the nose tube <NUM> of the high-speed surgical bur assembly <NUM> within the cavity <NUM> of the hub <NUM> relative to the hub <NUM>. The biasing member <NUM> may have tapered surfaces <NUM>, <NUM> on the proximal or distal ends to assist in engagement between the biasing member <NUM> and the nose tube <NUM>.

Referring to <FIG>. The surgical handpiece assembly <NUM> may also comprise a radial alignment member <NUM> disposed within the cavity <NUM> of the hub <NUM> proximal to the biasing member <NUM>. The radial alignment member <NUM> may be press-fit into the cavity <NUM> of the hub <NUM> such that no relative movement between the hub <NUM> and the radial alignment member <NUM> occurs. It is contemplated that the radial alignment member <NUM> and the hub <NUM> may be coupled to each other in another manner so long as no relative movement is permitted between the radial alignment member <NUM> and the hub <NUM>.

The radial alignment member <NUM> defines a notch <NUM> for receiving the projection <NUM> of the nose tube <NUM> to constrain a radial orientation of the nose tube <NUM> relative to the hub <NUM>. In the configuration illustrated in <FIG>, the radial alignment member <NUM> defines four notches <NUM> spaced circumferentially at equal angles relative to each other such that each notch <NUM> is spaced <NUM> (ninety) degrees from adjacent notches <NUM>. It is contemplated that three or fewer notches <NUM> may be employed for receiving the projection <NUM> of the nose tube <NUM> to constrain a radial orientation of the nose tube <NUM> relative to the hub <NUM>. It is also contemplated that five or more notches <NUM> may be used for receiving the projection <NUM> of the nose tube <NUM> to constrain a radial orientation of the nose tube <NUM> relative to the hub <NUM>. Further, it is contemplated that the spacing between the notches <NUM> may be unequal and disposed at any position arranged circumferentially. It is appreciated that the number of notches <NUM> may determine the number of possible radial orientations of the nose tube <NUM> relative to the hub <NUM>. Further, the spacing of the notches <NUM> may determine how far apart the radial orientations are. Permitting multiple orientations may be particularly advantageous when the nose tube <NUM> employs a bend. The bend may be oriented differently relative to the surgical handpiece assembly <NUM> based on which notch <NUM> of the radial alignment member <NUM> receives the projection <NUM> of the nose tube <NUM>.

The radial alignment member <NUM> may have an alignment wall <NUM> extending distally from the notch <NUM> for engaging the projection <NUM> of the nose tube <NUM>. The alignment wall <NUM> may radially position the nose tube <NUM> during engagement to permit the notch <NUM> to receive the projection <NUM> of the nose tube <NUM> if the projection <NUM> is not already radially aligned with the notch <NUM> of the radial alignment member <NUM>. Two alignment walls <NUM> may be employed for each notch <NUM> of the radial alignment member <NUM>; one on each side. Each of the two alignment walls <NUM> may taper inwardly toward the notch <NUM> such that contact between the alignment wall <NUM> of the radial alignment member <NUM> and the projection <NUM> of the nose tube <NUM> when the nose tube <NUM> is axially forced into the hub <NUM> results in relative rotation between the nose tube <NUM> and the hub <NUM> to orient the projection <NUM> into the notch <NUM>. In configurations where the radial alignment member <NUM> comprises multiple alignment walls <NUM>, consecutive alignment walls <NUM> between notches <NUM> may be tapered in opposite directions. The consecutive alignment walls <NUM> may also collectively form an edge <NUM> to mitigate a possibility of the projection <NUM> jamming into the radial alignment member <NUM> instead of radially positioning the projection <NUM> of the nose tube <NUM> into a notch <NUM> of the radial alignment member <NUM>. Configurations where the projection <NUM> has a rounded surface <NUM> further assists in mitigating jamming with the radial alignment member <NUM>.

As shown in <FIG>, the radial alignment member <NUM> may also include one or more flat surfaces <NUM> to further define each notch <NUM>. The flat surfaces <NUM> of the radial alignment member <NUM> may engage flat surfaces <NUM> of the projection <NUM> of the nose tube <NUM> when the projection <NUM> is received in the notch <NUM> to prevent relative rotation between the nose tube <NUM> and the hub <NUM>. With relative rotation between the nose tube <NUM> and the hub <NUM> prevented, axial movement between the nose tube <NUM> and the hub <NUM> resulting from the relative rotation is also prevented.

In the configuration illustrated in <FIG>, the radial alignment member <NUM> assists the distal shoulder <NUM> of the recess <NUM> of the hub <NUM> to retain the biasing member <NUM> in the recess <NUM> of the hub <NUM>. As noted above, the distal shoulder <NUM> prevents the biasing member <NUM> from exiting the recess in a distal direction. With the radial alignment member <NUM> positioned immediately proximal the biasing member <NUM>, the radial alignment member <NUM> forms a proximal shoulder of the recess <NUM> to prevent the biasing member <NUM> from exiting the recess <NUM> in a proximal direction. In other configurations, the bore <NUM> of the hub <NUM> may include a proximal shoulder (not shown) to define the proximal end of the recess <NUM> and the radial alignment member <NUM> may be positioned proximal to the proximal shoulder.

In some configurations, the biasing member <NUM> is configured to engage the distal shoulder <NUM> of the hub <NUM> and the proximal shoulder <NUM> of the nose tube <NUM> when the nose tube <NUM> is inserted in the cavity <NUM> of the hub <NUM> to force the projection <NUM> of the nose tube <NUM> toward the notch <NUM> of the radial alignment member <NUM>. If the projection <NUM> is already partly received by the notch <NUM>, engagement between the biasing member <NUM> and the shoulders <NUM>, <NUM> may force the projection <NUM> deeper into the notch <NUM> until engagement ceases or until the projection <NUM> abuts a proximal surface of the notch <NUM> and is fully received by the notch <NUM>.

As shown in <FIG>, the surgical handpiece assembly <NUM> also comprises a rotatable drive chuck <NUM>. The rotatable drive chuck <NUM> is configured to be rotated by a motor about a hub axis HX. A proximal portion <NUM> of the rotatable drive chuck <NUM> may engage a motor directly or the rotatable drive chuck <NUM> may engage a gear assembly or another assembly driven by a motor and configured to transfer torque from the motor to the rotatable drive chuck <NUM>. The rotatable drive chuck <NUM> is disposed at least partially within the cavity <NUM> of the hub <NUM> proximal to the radial alignment member <NUM> and configured to rotate relative to the hub <NUM>. The rotatable drive chuck <NUM> defines an opening <NUM> for receiving the proximal region <NUM> of the driveshaft <NUM>.

As shown in <FIG>, the rotatable drive chuck <NUM> comprises a driving portion <NUM> proximal of the opening <NUM>. The driving portion <NUM> has at least two driving surfaces <NUM> configured to engage the drive portion <NUM> of the proximal region <NUM> of driveshaft <NUM> to rotate the driveshaft <NUM>. The driving surfaces <NUM> of the driving portion <NUM> of the rotatable drive chuck <NUM> engage the drive surfaces <NUM> of the drive portion <NUM> of the driveshaft <NUM> when the driveshaft <NUM> is in the driving orientation and the high-speed surgical bur assembly <NUM> is coupled to the surgical handpiece assembly <NUM> (see <FIG>). The driveshaft <NUM> is in the driving orientation when the drive surfaces <NUM> of the driveshaft <NUM> are parallel to driving surfaces <NUM> of the driving portion <NUM> of the rotatable drive chuck <NUM>. In the configuration illustrated in <FIG>, the driving portion <NUM> comprises eight driving surfaces <NUM> to accommodate various orientations of the drive portion <NUM> of the driveshaft <NUM>. It is contemplated that there are multiple driving orientations when there are more than two driving surfaces <NUM>. For instance, in the configuration illustrated in <FIG>, there are four different driving orientations. Said differently, the driveshaft <NUM> may be rotated by the rotatable drive chuck <NUM> in four different radial orientations relative to the rotatable drive chuck <NUM>. It is also contemplated that the driving portion <NUM> may instead comprise between three and seven driving surfaces <NUM> to engage the drive portion <NUM> of the driveshaft <NUM>. It is also contemplated that the driving portion <NUM> may instead comprise nine or more driving surfaces <NUM> to engage the drive portion <NUM> of the driveshaft <NUM>.

The rotatable drive chuck <NUM> may also comprise an aligning portion <NUM> disposed between the driving portion <NUM> and the opening <NUM> of the rotatable drive chuck <NUM>. The aligning portion <NUM> may have an alignment edge <NUM> extending distally from the driving portion <NUM> of the rotatable drive chuck <NUM> toward the opening of the rotatable drive chuck <NUM>. The alignment edge <NUM> tapers away from the hub axis HX as the alignment edge <NUM> extends distally from the driving portion <NUM> of the rotatable drive chuck <NUM>. The alignment edge <NUM> of the aligning portion <NUM> is configured to engage the alignment portion <NUM> of the driveshaft <NUM> to rotate the driveshaft <NUM> into the driving orientation.

The aligning portion <NUM> of the rotatable drive chuck <NUM> may have a first ramped surface <NUM> extending distally from the driving portion <NUM> of the rotatable drive chuck <NUM> toward the opening <NUM> of the rotatable drive chuck <NUM>. The first ramped surface <NUM> tapers away from the hub axis HX as the first ramped surface <NUM> extends distally from the driving portion <NUM> of the rotatable drive chuck <NUM>. The aligning portion <NUM> of the rotatable drive chuck <NUM> may have a second ramped surface <NUM> distinct from and adjacent to the first ramped surface <NUM>. The second ramped surface <NUM> extends distally from the driving portion <NUM> of the rotatable drive chuck <NUM> toward the opening <NUM> of the rotatable drive chuck <NUM>. The second ramped surface <NUM> tapers away from the hub axis HX as the second ramped surface <NUM> extends distally from the driving portion <NUM> of the rotatable drive chuck <NUM>. The first and second ramped surfaces <NUM>, <NUM> collectively define the alignment edge <NUM> of the rotatable drive chuck <NUM>. In the configuration illustrated in <FIG>, the aligning portion <NUM> comprises four alignment edges <NUM>. Each alignment edge <NUM> is formed by a first ramped surface <NUM> and a second ramped surface <NUM>. In other configurations, the aligning portion <NUM> of the rotatable drive chuck <NUM> comprises three or fewer alignment edges <NUM>. In still other configurations, the aligning portion <NUM> comprises five or more alignment edges <NUM>. In some configurations, the first and second ramped surfaces <NUM>, <NUM> are symmetrical about the alignment edge <NUM>. In other configurations, the first and second ramped surfaces <NUM>, <NUM> are not symmetrical about the alignment edge <NUM>.

In one exemplary configuration, coupling between the high-speed surgical bur assembly <NUM> and the surgical handpiece assembly <NUM> is described below. A user may grasp the nose tube <NUM> of the high-speed surgical bur assembly <NUM> or another portion of the high-speed surgical bur assembly <NUM> and axially load (i.e., insert) the proximal portion <NUM> of the nose tube <NUM> and the proximal region <NUM> of the driveshaft <NUM> into the cavity <NUM> of the hub <NUM> of the surgical handpiece assembly <NUM>. After the nose tube <NUM> and driveshaft <NUM> have entered the cavity <NUM> to a certain depth, the nose tube <NUM> is radially and axially constrained relative to the hub <NUM> of the surgical handpiece assembly <NUM> and the driveshaft <NUM> is radially and axially constrained relative to the rotatable drive chuck <NUM> of the surgical handpiece assembly <NUM>. The constraints will be discussed in greater detail further below. As noted above, the driveshaft <NUM> is axially constrained to the nose tube <NUM> by the proximal and distal bushings <NUM>, <NUM> of the high-speed surgical bur assembly <NUM>. Further, the rotatable drive chuck <NUM> is axially constrained within the cavity <NUM> of the hub <NUM> by bushings <NUM> (see <FIG>) coupled to the hub <NUM>. As such, the driveshaft <NUM> is axially constrained relative to the rotatable drive chuck <NUM> when the nose tube <NUM> is axially constrained to the hub <NUM>. As for radially constraining the nose tube <NUM> and the driveshaft <NUM>, the driveshaft <NUM> is radially constrained relative to the rotatable drive chuck <NUM> prior to the nose tube <NUM> being radially constrained to the hub <NUM>. In other configurations, the driveshaft <NUM> and nose tube <NUM> may be radially constrained simultaneously. In still other configurations the nose tube <NUM> may be radially constrained before the driveshaft <NUM>. After both the driveshaft <NUM> and the nose tube <NUM> are radially constrained the nose tube <NUM> is axially constrained. Below, one exemplary configuration of constraining the nose tube <NUM> and the driveshaft <NUM> are described.

As the driveshaft <NUM> of the high-speed surgical bur assembly <NUM> enters the cavity <NUM> of the hub <NUM> of the surgical handpiece assembly <NUM>, the driveshaft <NUM> enters through the opening <NUM> of the rotatable drive chuck <NUM>. After entering through the opening <NUM> of the rotatable drive chuck <NUM>, the outer surface of the alignment portion <NUM> of the driveshaft <NUM> abuts one of the alignment edges <NUM> of the aligning portion <NUM> of the rotatable drive chuck <NUM>. As the driveshaft <NUM> continues to be axially loaded into the cavity <NUM> of the hub <NUM>, the engagement between the alignment portion <NUM> of the driveshaft <NUM> and the alignment edge <NUM> of the rotatable drive chuck <NUM> orients the drive portion <NUM> of the driveshaft <NUM> to the driving orientation. In the driving orientation, the drive surfaces <NUM> of the driveshaft <NUM> may engage the driving surfaces <NUM> of the rotatable drive chuck <NUM> to radially constrain the driveshaft <NUM> to the rotatable drive chuck <NUM>. When the drive surfaces <NUM> engage the driving surfaces <NUM>, torque may be transferred from the rotatable drive chuck <NUM> to the driveshaft <NUM> and ultimately to the cutting tool <NUM>.

In one configuration illustrated in <FIG>, the rotatable drive chuck <NUM> may define a cut-out <NUM> for providing additional clearance between the rotatable drive chuck <NUM> and the proximal end of the driveshaft <NUM> when the high-speed surgical bur assembly <NUM> is coupled to the surgical handpiece assembly <NUM>. The additional clearance provided by the cut-out <NUM> may mitigate the chance that engagement between the proximal end of the driveshaft <NUM> and a surface of the rotatable drive chuck <NUM> occurs before the nose tube <NUM> is axially constrained to the hub <NUM>. In other words, the additional clearance provided by the cut-out <NUM> ensures that continued insertion of the driveshaft <NUM> in the rotatable drive chuck <NUM> does not interfere with axial coupling of the nose tube <NUM> to the hub <NUM>.

Engagement between the alignment portion <NUM> of the driveshaft <NUM> and the aligning portion <NUM> of the rotatable drive chuck <NUM> may permit rotation of the driveshaft <NUM> to the driving orientation to be accomplished exclusively by the user axially loading the high-speed surgical bur assembly <NUM> into the cavity <NUM> of the hub <NUM> of the surgical handpiece assembly <NUM>. In other words, the driveshaft <NUM> may be oriented to the driving orientation without a user grasping the cutting tool <NUM> or another portion of the driveshaft <NUM> to manipulate the driveshaft <NUM> to the driving orientation. It is contemplated that in some instances, the driveshaft <NUM> will enter the cavity <NUM> of the hub <NUM> in the driving orientation. In such an instance, the alignment portion <NUM> of the driveshaft <NUM> may not contact the aligning portion <NUM> of the rotatable drive chuck <NUM> and the driveshaft <NUM> may not engage anything until the drive portion <NUM> of the driveshaft <NUM> engages the driving portion <NUM> of the rotatable drive chuck <NUM>.

As shown in <FIG>, the nose tube <NUM> being axially and radially constrained, is illustrated. The driveshaft <NUM> in <FIG> has been removed to better illustrate the engagement between the nose tube <NUM> and the surgical handpiece assembly <NUM>. Referring to <FIG>, the surgical handpiece assembly <NUM> is shown with the hub <NUM>, the radial alignment member <NUM>, and the biasing member <NUM>. The biasing member <NUM> is shown in an unbiased, compressed state. As the nose tube <NUM> enters the cavity <NUM> of the hub <NUM> of the surgical handpiece assembly <NUM>, the nose tube <NUM> engages the biasing member <NUM> by abutting the distal tapered surface <NUM> of the biasing member <NUM>. When a sufficient axial force is applied to the nose tube <NUM> to overcome a spring force of the biasing member <NUM>, the biasing member <NUM> expands to a biased state shown in <FIG> to accommodate the proximal portion <NUM> of the nose tube <NUM>. In many instances, the projection <NUM> of the nose tube <NUM> may be misaligned and may engage the alignment wall <NUM> of the radial alignment member <NUM> such that continued axial force applied to the nose tube <NUM> may result in relative rotation between the nose tube <NUM> and the hub <NUM> until the projection <NUM> is aligned with notch <NUM>. In other words, the nose tube <NUM> may be oriented so that the projection <NUM> of the nose tube <NUM> may be received by the notch <NUM> of the radial alignment member <NUM> without a user grasping the nose tube <NUM> to radially manipulate the nose tube <NUM>.

In some configurations, as shown in <FIG>, the biasing member <NUM> may be received in the recess <NUM> of the nose tube <NUM> and the proximal tapered surface <NUM> of the biasing member <NUM> may abut a proximal shoulder <NUM> of the recess on the nose tube <NUM> when the nose tube <NUM> is at a certain depth in the cavity <NUM> of the hub <NUM>. When the proximal tapered surface <NUM> of the biasing member <NUM> abuts the proximal shoulder <NUM> of the recess124 of the nose tube <NUM> and a distal end of the biasing member <NUM> abuts the distal shoulder <NUM> of the recess <NUM> of the hub <NUM>, the spring force of the biasing member <NUM> may be sufficient to engage the nose tube <NUM> to force the projection <NUM> of the nose tube <NUM> deeper into the notch <NUM> of the radial alignment member <NUM>. If the biasing member <NUM> has not returned to the unbiased, compressed state and the projection <NUM> of the nose tube <NUM> is fully received by the notch <NUM> of the radial alignment member <NUM> such that axial movement of the nose tube <NUM> in the proximal direction relative to the hub <NUM> is prevented, the biasing member <NUM> may continue to engage the nose tube <NUM> to axially constrain the nose tube <NUM> relative to the hub <NUM> and to keep a tight axial fit between the hub <NUM>, the biasing member <NUM>, the radial alignment member <NUM>, and the nose tube <NUM>. The tight axial fit may eliminate gaps that may have otherwise been present. Such gaps may have been formed from wear, tolerance stack-up, etc. In other configurations, the recess <NUM> of the nose tube <NUM> receives the biasing member <NUM> and the biasing member <NUM> constrains the depth of the nose tube <NUM> relative to the hub <NUM>. In such a configuration, the biasing member <NUM> does not continue to engage the nose tube <NUM> to keep a tight axial fit between the hub <NUM>, the biasing member <NUM>, the radial alignment member <NUM>, and the nose tube <NUM>.

It is contemplated that in some instances, the nose tube <NUM> will enter the cavity <NUM> of the hub <NUM> in a radial orientation such that the projection <NUM> of the nose tube <NUM> may be received by the notch <NUM> of the radial alignment member <NUM> without rotating the nose tube <NUM>. In such an instance, the projection <NUM> of the nose tube <NUM> may not contact the alignment wall <NUM> of the radial alignment member <NUM> and the projection <NUM> of the nose tube <NUM> may not engage anything until the projection <NUM> of the nose tube <NUM> is received by the notch <NUM> of the radial alignment member <NUM>.

It will be further appreciated that the terms "include," "includes," and "including" have the same meaning as the terms "comprise," "comprises," and "comprising. " Moreover, it will be appreciated that terms such as "first," "second," "third," and the like are used herein to differentiate certain structural features and components for the non-limiting, illustrative purposes of clarity and consistency.

Several configurations have been discussed in the foregoing description. However, the configurations discussed herein are not intended to be exhaustive or limit the invention to any particular form. The terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Claim 1:
A high-speed surgical bur assembly (<NUM>) configured to cut tissue and to be coupled to a surgical handpiece assembly (<NUM>), the high-speed surgical bur assembly (<NUM>) comprising:
a nose tube (<NUM>) defining a lumen extending between proximal and distal ends of the nose tube (<NUM>), the nose tube (<NUM>) having a proximal portion (<NUM>) extending along an axis (AX), the proximal portion (<NUM>) of the nose tube (<NUM>) having an outer surface defining a recess (<NUM>) for receiving a biasing member (<NUM>) of the surgical handpiece assembly (<NUM>) to constrain a depth of the nose tube (<NUM>) relative to the surgical handpiece assembly (<NUM>), and the nose tube (<NUM>) comprising a projection (<NUM>);
a driveshaft (<NUM>) at least partially disposed within the lumen of the nose tube (<NUM>) and configured to rotate relative to the nose tube (<NUM>), the driveshaft (<NUM>) having a drive portion (<NUM>) at a proximal region (<NUM>) of the driveshaft (<NUM>) for engaging a rotatable drive chuck (<NUM>) of the surgical handpiece assembly (<NUM>); and
a cutting tool (<NUM>) coupled to a distal region of the driveshaft (<NUM>) opposite the drive portion (<NUM>), the cutting tool (<NUM>) configured to rotate with the driveshaft (<NUM>) relative to the nose tube (<NUM>) in response to rotation of the rotatable drive chuck (<NUM>) of the surgical handpiece assembly (<NUM>);
characterized in that
the projection (<NUM>) of the nose tube (<NUM>) is disposed proximal to the recess (<NUM>) and configured to constrain a radial orientation of the nose tube (<NUM>) relative to the surgical handpiece assembly (<NUM>), wherein the projection (<NUM>) of the proximal portion (<NUM>) of the nose tube (<NUM>) extends proximally and generally parallel to the axis (AX).