Patent Description:
A system for use with a microwave antenna as disclosed in <CIT> includes a microwave antenna configured to deliver microwave energy from a power source to tissue and a sensor module in operative communication with the power source and configured to detect a reflectance parameter. The system further includes a jacket adapted to at least partially surround the microwave antenna to define a fluid channel between the jacket and the microwave antenna. A plurality of fluid distribution ports are defined through the jacket and are in fluid communication with the fluid channel to permit the flow of fluid through the jacket. The system further includes a fluid pumping system operably coupled to the power source and configured to selectively provide cooling fluid to the fluid channel for distribution through the fluid distribution ports based on the reflectance parameter.

<CIT> discloses an ultrasonic surgical handpiece assembly comprising a surgical handpiece for use with an irrigation sleeve and ultrasonic tip. The surgical handpiece may comprise a piezoelectric transducer disposed within a housing and configured to manipulate the ultrasonic tip. One or more lumens and/or a flex circuit including an antenna may be disposed within the surgical handpiece housing. The lumen(s) may be configured to provide irrigation and/or aspiration to the irrigation sleeve and/or ultrasonic tip. The irrigation sleeve may comprise a second antenna configured to communicate with the ultrasonic handpiece antenna. The irrigation sleeve may further comprise an alignment and/or coupling feature configured to removably secure the irrigation sleeve to the housing and orient the second antenna relative to the ultrasonic handpiece antenna. The irrigation sleeve may further comprise a lumen for supplying irrigation and/or aspiration to the ultrasonic tip.

An irrigation sleeve for an ultrasonic surgical assembly is defined in claim <NUM> and an ultrasonic surgical assembly comprising the irrigation sleeve is defined in claim <NUM>.

An exemplary ultrasonic surgical assembly to provide air cooling of an ultrasonic tip is disclosed. The ultrasonic surgical assembly includes an ultrasonic tip and an irrigation sleeve. The ultrasonic tip comprises a shaft and a cutting portion and has a first side and a second side. The first side is substantially planar and extends from a proximal end to a distal end. The second side is substantially planar, is disposed opposite the first side, and extends from the proximal end to the distal end. The cutting portion includes a cutting head, which is disposed at the distal end. The ultrasonic tip is removably coupled to a horn. The shaft further comprises a longitudinal axis. The irrigation sleeve has a distal region and a proximal region and defines a lumen that extends along the longitudinal axis. The irrigation sleeve at least partially surrounds the shaft and defines an inlet aperture. The irrigation sleeve further comprises a first conduit in fluid communication with the lumen. The first conduit has an outlet aperture and is configured for being connected to a liquid source. The ultrasonic tip further comprises a sealing member coupled to its outer surface and further defines a first bore and a second bore. The first bore defines an air inlet disposed proximal to the sealing member, and the second bore extends from the proximal end of the shaft to the first bore to form a fluid path between the first bore and the second bore.

A second ultrasonic surgical assembly corresponding to the ultrasonic surgical assembly of claim <NUM> is disclosed. The assembly includes an ultrasonic instrument, an ultrasonic tip, and an irrigation sleeve. The ultrasonic instrument comprises a housing, a transducer, and a horn. The housing comprises a proximal portion and a distal portion. The transducer is at least partially disposed within the housing. The horn is coupled to the transducer. The ultrasonic tip comprises a shaft and is removably coupled to the horn. The irrigation sleeve defines a lumen and comprises a body, a sheath, and an irrigation conduit. The body is releasably coupled to the distal portion of the housing and has a distal region and a proximal region. The body defines a helical groove which at least partially surrounds the shaft when the ultrasonic tip is in the lumen of the irrigation sleeve. The sheath is coupled to and disposed over a portion of the body to surround at least a full revolution of the helical groove. The sheath has a proximal end and an opposing distal end. The irrigation conduit is disposed within the helical groove for conveying irrigation fluid and defines an inlet aperture and an outlet aperture. The inlet aperture is disposed at the proximal region of the body, and an outlet aperture is disposed at a distal region of the body. The irrigation fluid enters the irrigation conduit at the inlet aperture and exits the irrigation conduit at the outlet aperture.

An exemplary ultrasonic tip is disclosed that comprises a shaft and a cutting portion. The shaft defines a longitudinal axis. The cutting portion defines a first side that is substantially planar and a second side that is substantially planar and includes a cutting head. The cutting portion includes a base portion having a transverse dimension between the first side and the second side that extends perpendicular to a longitudinal axis of the cutting head. The cutting portion further includes a tapered portion that comprises a bevel and that extends from the base portion to a cutting edge. The cutting edge comprises a length and has a U-shaped profile having a first leg portion, a second leg portion, and an arcuate shaped distal portion. The first leg portion and the second leg portion are parallel to one another. Moreover, the largest cross-sectional area of the ultrasonic tip defines a cross-sectional area of a first slice. A cross-sectional area of a second slice is defined at a location <NUM> proximal to a distal end of the ultrasonic tip. The second slice and the first slice are each perpendicular to the longitudinal axis of the shaft. The cross-sectional area of the second slice is <NUM> - <NUM> % of the cross-sectional area of the first slice.

An exemplary second ultrasonic surgical assembly to provide air cooling of an ultrasonic tip is disclosed. The ultrasonic surgical assembly comprises an ultrasonic instrument, an ultrasonic tip, an irrigation sleeve, and a sealing member. The ultrasonic instrument has a proximal region and a distal region and comprises a housing, a transducer, and a horn. The housing comprises a proximal portion and a distal portion. The transducer is at least partially disposed within the housing. The horn is coupled to the transducer, which is configured to be coupled to a suction source by a first coupler. The ultrasonic tip comprises a shaft and a cutting portion and is removably coupled to the horn by a tip coupler. The shaft comprises a longitudinal axis. The irrigation sleeve has a distal region and a proximal region and defines a lumen. The irrigation sleeve at least partially surrounds the shaft and defines an inlet aperture configured to receive irrigation liquid from an irrigation source. The irrigation sleeve further comprises a first conduit in fluid communication with the lumen. The first conduit is configured to convey irrigation liquid from the inlet aperture to an outlet aperture. The sealing member is positioned between an outer surface of the ultrasonic tip and an inner surface of the lumen. The ultrasonic tip defines a first bore and a second bore. The first bore defines an air inlet disposed proximal to the sealing member when the irrigation sleeve and the ultrasonic tip are coupled to the ultrasonic instrument. The second bore extends from a proximal end of the ultrasonic tip to the first bore. The second bore is in communication with the suction source through the tip coupler. The irrigation sleeve defines a third bore proximal the first bore when the irrigation sleeve and the ultrasonic tip are coupled to the ultrasonic instrument. The ultrasonic surgical assembly defines a path to draw air from an ambient environment through the third bore, then through the first bore, and back through the second bore before the air exits the ultrasonic surgical assembly at the first coupler.

An exemplary method of cutting bone with an ultrasonic tip is disclosed. The method includes providing an ultrasonic tip, which comprises a shaft and a cutting portion and is removably coupled to a horn by a tip coupler. The horn is coupled to a transducer, and the transducer is coupled to a suction source by a first coupler. The shaft comprises a longitudinal axis. The ultrasonic tip defines a first bore defining an air inlet and a second bore extending from a proximal end of the ultrasonic tip to the first bore. The first bore is transverse to the second bore, and the second bore is in communication with the suction source via the tip coupler. The method further includes providing an irrigation sleeve having a distal region and a proximal region and defining a lumen. The irrigation sleeve at least partially surrounds the shaft and is configured to be coupled to an irrigation source with an inlet aperture configured to receive irrigation liquid from the irrigation source. The irrigation sleeve defines a first conduit in fluid communication with the lumen. The first conduit is configured to convey irrigation liquid from the inlet aperture to an outlet aperture. The method further includes drawing air via the suction source through the second bore and the first bore to cool the ultrasonic tip.

An exemplary third ultrasonic surgical assembly is disclosed. The assembly includes an ultrasonic instrument, an ultrasonic tip, and an irrigation sleeve. The ultrasonic instrument includes a housing, a transducer, and a horn. The housing comprises a proximal portion and a distal portion. The transducer is at least partially disposed within the housing. The horn is coupled to the transducer. The ultrasonic tip comprises a shaft and a cutting portion and is removably coupled to the horn. The irrigation sleeve defines a lumen and comprises a body releasably coupled to the distal portion of the housing and has a distal region and a proximal region. The ultrasonic tip further comprises an annular sealing member and defines a groove, with the annular sealing member disposed around the groove, disposed at the proximal region of the body, and positioned between an outer surface of the ultrasonic tip and an inner surface of the lumen when the sleeve and ultrasonic tip are coupled to the ultrasonic instrument. The annular sealing member is configured to prevent movement of fluid proximally to the annular sealing member.

An exemplary fourth ultrasonic surgical assembly is disclosed. The assembly includes an ultrasonic instrument, and an irrigation sleeve. The ultrasonic instrument includes a housing, a transducer, and a horn. The housing comprises a proximal portion and a distal portion. The transducer is at least partially disposed within the housing. The horn is coupled to the transducer. The irrigation sleeve defines a lumen and is configured to be removably coupled to a first ultrasonic tip and a second ultrasonic tip. Each of the first ultrasonic tip and the second ultrasonic tip is configured to be removably coupled to the horn by a tip coupler. Each of the first ultrasonic tip and the second ultrasonic tip comprises a shaft, a cutting portion, and an annular sealing member. The cutting portion of the first ultrasonic tip comprises a cutting geometry that is distinct from a cutting geometry of the cutting portion of the second ultrasonic tip. The first ultrasonic tip defines a first groove positioned at a first distance from the tip coupler of the first ultrasonic tip. The second ultrasonic tip defines a second groove positioned at a second distance from the tip coupler of the second ultrasonic tip. The first distance from the tip coupler of the first ultrasonic tip is not equal to the second distance from the tip coupler of the second ultrasonic tip. Each of the first ultrasonic tip and the second ultrasonic tip includes the annular sealing member disposed around the respective first and second grooves. The irrigation sleeve comprises a body and an irrigation conduit. The body is releasably coupled to the distal portion of the housing. The irrigation conduit is coupled to the body and configured to convey irrigation fluid. The irrigation conduit further defines an inlet aperture disposed at a proximal region of the body, and an outlet aperture disposed at a distal region of the body, wherein irrigation fluid enters the irrigation conduit at the inlet aperture and exits the irrigation conduit at the outlet aperture.

As medical professionals strive for reducing the size of the incisions and the amount of recovery time required following invasive medical procedures, the size of medical instruments used in various medical procedures have become smaller. Many of the medical instruments utilized in performing the various medical procedures may include the use of a cutting accessory, such as an ultrasonic tip. In performing a cutting, shaving, or shaping operation, the cutting accessory will be exposed to varying amounts of force creating stresses within the cutting accessory.

Many of these cutting accessories may also require the use of irrigation or aspiration (i.e., suction) to reduce heat and/or remove debris at the surgical site. One example of a surgical instrument that may utilize irrigation and/or aspiration systems is an ultrasonic surgical handpiece. Generally, one or more lines may be coupled to the ultrasonic surgical handpiece to supply irrigation and/or suction. The ultrasonic surgical handpiece may further comprise a sleeve comprising one or more lumens that may be utilized to direct fluid from an irrigation source toward the surgical site and/or the cutting accessory, i.e., the ultrasonic tip. One such ultrasonic surgical handpiece is described in <CIT>, entitled "Ultrasonic Surgical Handpiece Assembly".

However, a cutting accessory that is particularly flat or narrow frequently may not include a lumen throughout the entire length of the cutting accessory, i.e., to the cutting edge or blade. Moreover, a higher current within the cutting accessory due to the lack of an aspiration or cooling lumen throughout may cause over-heating of the handpiece. The excessive heat build-up may adversely affects the life span of the handpiece and may also be felt by the surgeon.

Additionally, the shape and geometry of the cutting accessory may affect the amplification factor, or gain, associated with the ultrasonic instrument. By configuring the ultrasonic tip with lower gain in certain implementations, the inventors realized that various benefits may be achieved, including a reduction in stalling, drawing less power to drive the tip, and the ability to drive the tip at a higher current to the ultrasonic handpiece, which may improve cutting rate without an increase in stalling.

<FIG> and <FIG> illustrate an exemplary configuration of an ultrasonic surgical handpiece assembly <NUM> that may be utilized by a medical professional to remove biological material from a patient. The ultrasonic surgical handpiece assembly <NUM> may comprise an ultrasonic handpiece <NUM> including a distal housing portion <NUM> and a proximal housing portion <NUM>. An irrigation sleeve <NUM> may be removably coupled to the distal housing portion <NUM> of the ultrasonic surgical handpiece <NUM>. The irrigation sleeve <NUM> and an ultrasonic tip <NUM> may be configured such that the irrigation sleeve <NUM> surrounds at least a portion of the ultrasonic tip <NUM> along a length of the ultrasonic tip <NUM> when both the irrigation sleeve <NUM> and the ultrasonic tip <NUM> are coupled to the ultrasonic handpiece <NUM>. The irrigation sleeve <NUM> and the ultrasonic tip <NUM> may at least in part comprise an ultrasonic sleeve assembly <NUM>.

<FIG> illustrates a sectional view of the ultrasonic surgical handpiece assembly <NUM> of <FIG>. As illustrated in <FIG>, the ultrasonic handpiece <NUM> may comprise a transducer <NUM> disposed within a void defined by the distal housing portion <NUM> and the proximal housing portion <NUM> of the ultrasonic handpiece <NUM>. The transducer <NUM> may comprise a plurality of piezoelectric elements or magnetostrictive elements configured to generate mechanical energy.

The ultrasonic handpiece <NUM> may also comprise a horn <NUM> that may be at least partially disposed within the void defined by the distal housing portion <NUM> and the proximal housing portion <NUM> of the ultrasonic handpiece <NUM>. The horn <NUM> may comprise a distal end and a proximal end. The proximal end of the horn <NUM> may be coupled to a distal end of the transducer <NUM>. The transducer <NUM> may be configured to provide the mechanical energy generated by the piezoelectric element or magnetostrictive element to the horn <NUM>. The horn <NUM> may also be configured to define a horn lumen <NUM> that extends from the distal end to the proximal end of the horn <NUM>. The horn lumen <NUM> may define a portion of a passageway that extends through the ultrasonic handpiece <NUM> to provide aspiration. The horn lumen <NUM> has a distal end and a proximal end, and the proximal end may be in communication with a suction source <NUM>). The transducer <NUM> may be coupled to the suction source <NUM> via a coupler <NUM>.

The ultrasonic handpiece <NUM> may further comprise an irrigation line <NUM> that is disposed within the void defined by the distal housing portion <NUM> and the proximal housing portion <NUM> of the ultrasonic handpiece <NUM>. The irrigation line <NUM> may be configured to extend from the proximal end to the distal end of the ultrasonic handpiece <NUM>. The irrigation line <NUM> may serve to channel a liquid, such as water or saline from an irrigation system that is coupled to the ultrasonic handpiece <NUM> through the irrigation sleeve <NUM>. It should be appreciated that the irrigation line <NUM> may route directly from an irrigation source (not shown) to the irrigation sleeve <NUM> (i.e., the irrigation line <NUM> need not be always routed through the handpiece <NUM>).

The ultrasonic tip <NUM> may comprise a shaft <NUM> that includes a distal region <NUM>, an intermediate region <NUM>, and a proximal region <NUM>, all disposed along a longitudinal axis L1. The ultrasonic tip <NUM> may also comprise a coupling feature <NUM> positioned at the proximal region <NUM> of the shaft <NUM> and is configured to couple the proximal region <NUM> of the ultrasonic tip <NUM> to the distal end of the horn <NUM> to allow the horn <NUM> to be in mechanical communication with the ultrasonic tip <NUM>. The coupling feature <NUM> may be a threaded coupler <NUM> configured to engage a corresponding threaded coupler on the distal end of the horn <NUM>. The ultrasonic tip <NUM> may be threaded into the horn <NUM> and tightened to a predetermined torque specification to removably secure the ultrasonic tip <NUM> to the ultrasonic handpiece <NUM>. While not illustrated in the figures, it is contemplated that the coupling feature <NUM> may be configured as a quick connection, quarter turn fitting, or similar coupling mechanism. It is further contemplated that the coupling feature <NUM> may be configured to permanently affix the ultrasonic tip <NUM> to the handpiece <NUM>. For example, the ultrasonic tip <NUM> may be coupled to the ultrasonic handpiece <NUM> by a weld, epoxy, or similar coupling method.

Alternatively, it is also contemplated that the ultrasonic tip <NUM> and the horn <NUM> may be formed as a unitary component. In such a configuration, the ultrasonic tip <NUM> may include a base (horn) <NUM> for coupling to the transducer <NUM>, and a body comprised of the shaft <NUM> and a cutting portion <NUM>. The body <NUM>, <NUM> extends from and is coupled to the base <NUM> at the shaft <NUM>. The body <NUM>, <NUM> extends from the shaft <NUM> to the cutting portion <NUM> along the longitudinal axis L1.

In some aspects, such as the illustrated aspect, the shaft <NUM> is free of a lumen in the distal region <NUM>. Said differently, the ultrasonic tip may be free of a lumen in the portions of the cutting tip that feature a rectangular shaped cross-sectional area. The shaft <NUM> may be made of a metal material such as titanium alloy, stainless steel, etc. or a non-metallic material such as a composite, depending on the application. In one aspect, the shaft <NUM> and the cutting portion <NUM> may be integral, unitary, and one-piece. In another aspect, the cutting portion <NUM> of the ultrasonic tip <NUM> may be attached to the shaft <NUM> by a suitable mechanism such as threads (not shown).

<FIG> illustrates a top view of an exemplary configuration of the irrigation sleeve <NUM> having a distal region <NUM> and a proximal region <NUM>. The irrigation sleeve <NUM> may comprise an irrigation sleeve coupling mechanism <NUM> on the proximal region <NUM> of the irrigation sleeve <NUM>. The irrigation sleeve coupling mechanism <NUM> may comprise one or more fingers <NUM> extending proximally from the proximal region <NUM> of the irrigation sleeve <NUM>. Each of the one or more fingers <NUM> may comprise a tab <NUM> extending in a radially outward direction relative to a longitudinal axis L1 of the irrigation sleeve <NUM>. The fingers <NUM> act as the male fitting configured to couple with a female fitting (not shown) on the ultrasonic handpiece <NUM> to create a snap-fit or interference fit. It is contemplated that other types of irrigation sleeve coupling mechanisms <NUM> may be used to couple the irrigation sleeve <NUM> to the ultrasonic handpiece <NUM>. By way of example and not limitation, the irrigation sleeve coupling mechanisms <NUM> may be configured as a threaded connection. It should be appreciated that the irrigation sleeve <NUM> described herein may be used in conjunction with other tip designs than illustrated here.

Referring now to <FIG>, an exploded view an ultrasonic tip and irrigation sleeve assembly <NUM> is illustrated. The irrigation sleeve assembly <NUM> includes the irrigation sleeve <NUM> which defines a lumen <NUM> extending along the longitudinal axis L1. The irrigation sleeve <NUM> may have a sleeve body <NUM> defining a helical groove <NUM>. In an assembled configuration, and when the ultrasonic tip <NUM> is inserted through the irrigation sleeve <NUM>, the irrigation sleeve <NUM> may at least partially surround the shaft <NUM> of the ultrasonic tip <NUM> when the ultrasonic tip <NUM> is disposed within the lumen <NUM> of the irrigation sleeve <NUM> and the irrigation sleeve <NUM> is coupled to the handpiece.

The irrigation sleeve assembly <NUM> may further comprise a sheath <NUM> having a proximal end and a distal end to correspond with the proximal region <NUM> and distal region <NUM> of irrigation sleeve <NUM>, respectively. The sheath <NUM> may be coupled to and disposed over at least a portion of the sleeve body <NUM> to surround at least a full revolution of the helical groove <NUM>, but can optionally surround more than two or three revolutions of the helical groove to provide sufficient retention.

The location of helical groove <NUM> may be different on different tips. By way of example and not limitation, in some configurations, one ultrasonic tip may define a groove positioned at a first distance from a tip coupler (e.g., coupling feature <NUM>) of said tip, whereas a different ultrasonic tip may define a groove positioned at a second distance from a tip coupler (e.g., coupling feature <NUM>) of said tip. In some configurations, the first distance is different from the second distance. This may be useful because different tips may have different node and anti-node locations. It may be useful to position the sealing member align with the node or anti-node of the particular tip.

Referring to <FIG>, a sectional view of the irrigation sleeve assembly <NUM> of <FIG> in an assembled configuration with the tip inserted therethrough is illustrated. The assembled irrigation sleeve assembly <NUM> with the ultrasonic tip <NUM> inserted therethrough shows the ultrasonic tip <NUM> disposed within the lumen <NUM> such that the irrigation sleeve <NUM> partially surrounds the shaft <NUM>.

Referring now to <FIG>, a partial sectional view of ultrasonic tip <NUM>, the irrigation sleeve <NUM>, sheath <NUM>, and an irrigation conduit <NUM> of the irrigation sleeve assembly of <FIG> is illustrated. The sheath <NUM> is disposed at least partially over irrigation sleeve <NUM> to surround at least a full revolution of the helical groove <NUM>, covering the irrigation conduit <NUM>.

In some configurations, the sleeve body <NUM> may define a second helical groove <NUM>. The second helical groove <NUM> may be free of the irrigation conduit <NUM>, and may also be partially surrounded by the sheath <NUM>, in other words, one or more revolutions of the second helical groove <NUM> may be surrounded by the sheath <NUM>.

The sheath <NUM> may be comprised of a heat-shrink or other suitable material that allows it to deform to the shape of the irrigation conduit <NUM>, as well as the underlying contours of the sleeve body <NUM>, which may include the second helical groove <NUM>. When the sheath <NUM> is contoured to the second helical groove <NUM>, it may define undulations <NUM> useful for gripping by a user.

Referring again to <FIG>, the irrigation sleeve assembly <NUM> may further comprise the irrigation conduit <NUM> disposed within the helical groove <NUM> for conveying irrigation fluid. The irrigation conduit <NUM> may be in fluid communication with or adjacent to the lumen <NUM> and may be connected to a liquid source (not shown). The irrigation conduit <NUM> may define an inlet aperture <NUM> (disposed at the proximal region <NUM> of the sleeve body <NUM> when the irrigation sleeve assembly <NUM> is in an assembled configuration), and an outlet aperture <NUM> (disposed at a distal region <NUM> of the sleeve body <NUM> when the irrigation sleeve assembly <NUM> is in an assembled configuration). The irrigation fluid may enter the irrigation conduit <NUM> at the inlet aperture <NUM> and exit the irrigation conduit <NUM> at the outlet aperture <NUM>. In some configurations, the irrigation conduit <NUM> may comprise a single member defining a continuous length between the inlet aperture <NUM> and the outlet aperture <NUM>. The irrigation conduit <NUM> may comprise a flexible material such that the irrigation conduit <NUM> may be configured to couple directly to a corresponding port of the surgical handpiece <NUM>. In other words, the irrigation conduit <NUM> may be formed of a material that can be deformed such that the inlet aperture <NUM> can partially engulf the corresponding port of the ultrasonic handpiece <NUM> to form the connection to the irrigation source. The helical shape of the groove <NUM> ensures that the irrigation conduit <NUM> similarly has a helical shape. This helical shape of the irrigation conduit <NUM> (tube) and groove <NUM> provide for a longer fluid return path than a straight return path. This longer path makes it more difficult for fluid to move backward in a proximal direction after it has been initially conveyed through the irrigation conduit <NUM>.

After the fluid has been conveyed through the irrigation conduit <NUM> distally along the sleeve body <NUM>, the fluid may exit the irrigation conduit <NUM> at the outlet aperture <NUM>. From there, the fluid may spread to the surface of the sleeve body <NUM> and/or the shaft <NUM>. In some circumstances, the fluid may return to the aperture <NUM> and backflow through the irrigation conduit <NUM>. Otherwise, the fluid may return proximally along the sleeve body <NUM> in a path that flows between an outer diameter of the irrigation conduit <NUM> and an inner surface of the sleeve body <NUM> within the sheath <NUM>.

One of the irrigation sleeve <NUM> and the ultrasonic tip <NUM> may include a sealing member <NUM>. The sealing member <NUM> may be an annular sealing member, including, by way of example and not limitation, an O-ring. In some configurations, the sealing member <NUM> may be coupled to the tip <NUM>. In such an implementation, the sealing member <NUM> is positioned around a groove <NUM> defined in an outer surface of the tip <NUM>. This may provide for the sealing member <NUM> being positioned between the outer surface of the ultrasonic tip <NUM> and an inner surface of the lumen <NUM>, which may prevent movement of fluid proximal to the sealing member <NUM> from the outlet aperture <NUM>. Alternatively, the sealing member <NUM> may be coupled to the sleeve <NUM>, and be positioned to engage the outer surface of the tip <NUM>, again to prevent movement of fluid proximal to the sealing member <NUM> from the outlet aperture <NUM>.

The sealing member <NUM> may be also used to dampen the amplitude of vibration of the ultrasonic tip <NUM>. The amplitude of vibration at any point along the ultrasonic tip <NUM> may depend upon the location along the ultrasonic tip <NUM> at which vibration is measured. The point along a standing wave where the wave has minimum amplitude is generally referred to as a node. At a node, the vibratory motion is typically minimal. Because the sealing member <NUM> may be coupled directly to the tip <NUM>, it may be situated anywhere on the ultrasonic tip <NUM> to decrease transverse motion of the tip <NUM>. In some configurations, it may be suitable to situate the sealing member <NUM> at or near a node on the tip <NUM>. The location of a node may be different on different ultrasonic tips.

Moreover, because the sealing member <NUM> may be coupled directly to the tip <NUM>, any sharp surfaces of the ultrasonic tip <NUM> will never contact the sealing member <NUM> during placement of the sleeve assembly over the ultrasonic tip <NUM>. Thus, the sealing member <NUM> is protected from abrasion and other damage when the ultrasonic tip <NUM> is placed over the sleeve <NUM>. Placement of the sealing member <NUM> on the ultrasonic tip <NUM> rather than the irrigation sleeve <NUM> also prevents the sealing member <NUM> from spontaneously sliding off or out of the irrigation sleeve assembly <NUM>.

Referring now to <FIG>, an alternate sectional view of the irrigation sleeve assembly with the tip inserted therethrough of <FIG> in an assembled configuration is illustrated. The ultrasonic tip <NUM> may define a first bore <NUM> that behaves as an air inlet. This first bore <NUM> may be disposed proximal to the sealing member <NUM> when the irrigation sleeve assembly <NUM> including the ultrasonic tip <NUM> are coupled to the handpiece <NUM>. In some configurations, the first bore <NUM> is located distal the sealing member <NUM>. A second bore <NUM> may extend from the proximal region <NUM> of the shaft <NUM> from the threaded coupler <NUM> to the first bore <NUM>. In other words, the first bore <NUM> and the second bore <NUM> are positioned to be in fluid communication with one another with the first bore <NUM> transverse the longitudinal axis L1 of the ultrasonic tip <NUM> and the second bore <NUM> is concentric with the longitudinal axis L1 of the tip <NUM>. In one example, the axis N1 of the first bore <NUM> may be perpendicular to an axis N2 of the second bore <NUM>. In some configurations, the first bore <NUM> may comprise a single bore. In other configurations, such as the configuration illustrated in <FIG>, the first bore <NUM> may extend laterally from one side of the ultrasonic tip <NUM> to the other to form a first bore <NUM> in each side of ultrasonic tip <NUM>. However, in other configurations, more than one first bore <NUM> may be included in ultrasonic tip <NUM>, wherein each of more than one first bore <NUM> is separate from one another (but each may still in communication with second bore <NUM>), rather than forming a single channel with a first bore <NUM> at each end as shown in <FIG>. Furthermore, the first bore <NUM> need not extend all the way through the tip <NUM>, so long as the first bore <NUM> extends from the outermost periphery to the second bore <NUM>. If there are a plurality of paths defined from the outer periphery of the ultrasonic tip <NUM> to the second bore <NUM>, those bores may be arranged in a variety of ways, such as being circumferentially arranged about the surface of the tip <NUM>.

In some configurations, the irrigation sleeve assembly <NUM> further comprises a third bore <NUM> proximal the first bore <NUM> when the irrigation sleeve assembly <NUM> including the ultrasonic tip <NUM> are coupled to the handpiece. More particularly, the sleeve body <NUM> may define third bore <NUM> to further facilitate air ingress from the ambient environment to the first bore <NUM>. Of course, it is contemplated that the irrigation sleeve assembly <NUM> may include more than one third bore <NUM> that defines an aperture to allow ambient air to move from outside the irrigation sleeve assembly <NUM> to the first bore <NUM> when the suction source <NUM> is coupled to the tip <NUM>.

In the illustrated configurations, the inlet aperture <NUM>, the outlet aperture <NUM>, the first bore <NUM>, the second bore <NUM>, and the third bore <NUM> all have circular cross-sectional shapes. However, in some configurations, all or any combinations of the inlet aperture <NUM>, the outlet aperture <NUM>, the first bore <NUM>, the second bore <NUM>, and/or the third bore <NUM> may have a shape other than a circular shape, such as various polygonal shapes or elliptical shapes.

The irrigation sleeve <NUM> may be made from any polymer, for example, a thermoplastic. The distal region <NUM> of the irrigation sleeve <NUM> may have a portion of frangible sections that could be cut or snipped to change the length of the irrigation sleeve <NUM>.

Referring again to <FIG>, when the irrigation sleeve assembly <NUM> is coupled to an irrigation source by a coupler, such as irrigation line <NUM>, it may draw irrigation liquid through the irrigation source via the inlet aperture <NUM>. The irrigation conduit <NUM> may then convey the irrigation liquid through the inlet aperture <NUM> to the outlet aperture <NUM>. The conveyance of irrigation liquid through the irrigation sleeve assembly <NUM> helps provide cooling to the shaft <NUM> of the ultrasonic tip <NUM>. Additionally, it may help prevent the irrigation sleeve <NUM> from becoming deformed or melting from excessive heat generated by the motion of the ultrasonic cutting.

In addition, when the irrigation sleeve assembly <NUM> including the ultrasonic tip <NUM> are coupled to the handpiece <NUM>, the ultrasonic tip <NUM> draws air through the third bore <NUM>, then through the first bore <NUM>, back through the second bore <NUM>, and ultimately out through the coupler <NUM>. This movement of air aids in cooling the tip in the area near the sealing member <NUM>, which is prone to overheating due to frictional heat generated by the relative motion between the sealing member <NUM> and the irrigation sleeve assembly <NUM>.

In addition, the air suction through the tip and/or the sleeve may operates as a smoke evacuation device in some applications. In the illustrated configuration, the ultrasonic tip <NUM> may be used for lumbar procedures and other relatively "heavy duty" bone-cutting procedures that produce larger amounts of smoke, dust particles, and airborne debris compared to other procedures. The air suction feature may pull some of this from the ambient air surrounding the ultrasonic handpiece <NUM> and evacuate it through the handpiece <NUM>. The instrument may be used in conjunction with a smoke filter to remove these particulates from the ambient air once aspirated through the tip <NUM>.

Referring now to <FIG>, a top view and a side view of a distal portion of the ultrasonic tip including a cutting head are illustrated. The ultrasonic tip <NUM> may comprise a first side <NUM> that is substantially planar. The ultrasonic tip <NUM> may further comprise a second side <NUM> that is substantially planar that is disposed opposite the first side <NUM>. The ultrasonic tip <NUM> may further comprise a cutting head (also referred to herein as a "cutting portion") <NUM> disposed distal the shaft <NUM>. The cutting head <NUM> may comprise a base portion <NUM> having a transverse dimension T1 between the first side <NUM> and the second side <NUM>. The transverse dimension T1 may extend perpendicular to the longitudinal axis L1 of the cutting head <NUM>. The cutting head <NUM> may further comprise a tapered portion <NUM> comprising a bevel that extends from the base portion <NUM> to a cutting edge <NUM>. By way of example and not limitation, in a preferred configuration, the base portion <NUM> has a transverse dimension of at least <NUM> millimeters. It should be appreciate that other ultrasonic tips may be used with the irrigation sleeve assembly shown above, such as those without the cutting head features described in this application, such as those shown in <CIT>, <CIT>, <CIT>, and <CIT>. Similarly, it should be appreciated that the ultrasonic tip may be used with other irrigation sleeve assemblies, such as those shown in <CIT>.

The cutting edge <NUM> comprises a length and may have a U-shaped profile having a first leg portion <NUM>, a second leg portion <NUM>, and an arcuate shaped distal portion <NUM>. By way of example and not limitation, in a preferred configuration, the arcuate shaped distal portion <NUM> has a thickness of at least <NUM> millimeters. The first leg portion <NUM> and the second leg portion <NUM> may be parallel to one another and may each comprise a plurality of cutting teeth, one of which is labeled <NUM>. In some configurations, no more than one half of the length of the cutting edge <NUM> may have cutting teeth <NUM>. In other configurations, more than one half of the length of the cutting edge <NUM> may have cutting teeth <NUM>. In some configurations, the arcuate shaped distal portion <NUM> is free from cutting teeth <NUM>, as is shown in the illustrated configuration in <FIG>.

The cutting portion <NUM> defines a centerline <NUM> along the longitudinal axis L1. Moreover, the plurality of cutting teeth <NUM> comprise at least two adjacent cutting teeth <NUM> and a notch <NUM> between each of the adjacent cutting teeth <NUM>. The notch <NUM> has a transverse dimension T2 along a notch base <NUM>. Each of the cutting teeth <NUM> has a tooth cutting edge <NUM>. In some configurations, the transverse dimension T2 of the notch <NUM> is at least <NUM> times less than the transverse dimension T1 of the base portion <NUM>.

The centerline <NUM> to the tooth cutting edge <NUM> defines a first distance A1. The centerline <NUM> to the notch base <NUM> defines a second distance A2. The centerline <NUM> to a starting point of the tapered portion <NUM> defines a third distance A3. In some configurations, the difference between the first distance A1 and the second distance A2 is less than or equal to <NUM>. In some configurations, the first distance A1 is greater than <NUM> times the third distance A3 but is less than <NUM> times the third distance A3. In the illustrated example, and not by way of limitation, the first distance A1 is <NUM>, the second distance A2 is <NUM>, and the third distance A3 is <NUM>. In this example, the difference between the first distance A1 and the second distance A2 is exactly <NUM>. Also, in this example, the first distance A1 is approximately <NUM> times greater than the third distance A3.

The ultrasonic tip <NUM> may be useful in cutting through both hard and soft tissues. The tooth cutting edges <NUM> allow for cutting through hard tissue, such as cortical bone. The serrated tooth cutting edges <NUM> may perform a saw-like operation to cut through denser tissue. By contrast, the cutting edge <NUM> is a smooth, continuous blade. However, although it may be sharp enough to cut through hard tissue, it may be blunt enough to be atraumatic relative to contacted soft tissue. By way of example and not limitation, the thickness of the cutting edge <NUM> may be <NUM> +/- <NUM>. As such, the cutting edge <NUM> can contact soft tissue with minimal risk of puncturing critical structures, such as the spinal cord. The surgeon will feel a tactile change when the cutting edge <NUM> moves between hard tissue and soft tissue due to the natural differences in the densities between the different tissue structures, indicating the need to terminate cutting when the cutting edge <NUM> has reached soft tissue. Thus, the ultrasonic tip <NUM> offers an advantage over the conventional, sharp bone-cutting blades because it is capable of cutting through hard bone structures with both its teeth edges <NUM> and the cutting edge <NUM>, while avoiding trauma to underlying soft tissues.

Referring again to <FIG>, different points along the shaft <NUM> have varying cross-sectional areas. Although transducers and ultrasonic tips are typically designed to have the same resonance frequency in longitudinal resonance devices, a decrease in the cross-sectional area along the length of the ultrasonic tip can amplify the vibrational velocity of the transducer output face. The amplification factor, otherwise known as gain, is determined by the reduction in cross-sectional area, as well as the shape of the ultrasonic tip. Gain can be measured by dividing the tip displacement by the handpiece displacement.

In the illustrated configuration, a cross-sectional area of a first slice SL1 is defined as the largest circular cross-sectional area of the ultrasonic tip <NUM> and which defines a plane perpendicular to the longitudinal axis L1. <FIG> illustrates a sectional view of the ultrasonic tip of <FIG> at the first cross-sectional area. A cross-sectional area of a second slice SL2 is defined at a location is <NUM> proximal to the distal end of the tip. The second slice SL2 defines a plane perpendicular to the longitudinal axis L1, and the second slice SL2 is distal to the first slice SL1. <FIG> illustrates a sectional view of the ultrasonic tip of <FIG> at the second slice.

The cross-sectional area of the second slice SL2 is <NUM> to <NUM> times smaller than the cross-sectional area of the first slice SL1. In other words, the cross-sectional area of the second slice SL2 is <NUM>-<NUM>, <NUM> to <NUM>, <NUM>-<NUM>, or <NUM> - <NUM> % of the cross-sectional area of the first slice SL1. This results in an ultrasonic tip having a low gain. The low gain of the of the ultrasonic tip <NUM>, which is calculated by dividing the ultrasonic tip <NUM> displacement by the ultrasonic handpiece <NUM> displacement, results in a reduction in stalling of the cutting portion <NUM> (e.g., cutting head <NUM>), which improves performance of the ultrasonic tip <NUM> overall. It also requires drawing less power to drive the ultrasonic tip <NUM> and allows for driving the ultrasonic tip <NUM> at a higher current, which may improve cutting rate without an increase in stalling of the cutting portion <NUM> (e.g., cutting head <NUM>).

For example and not by way of limitation, in the illustrated configuration, a diameter of the first slice SL1 is <NUM>, with a gun drill hole having a diameter of approximately <NUM>. In this configuration, the cross-sectional area of the first slice SL1 is approximately <NUM><NUM>. In some configurations, the cross-sectional area of the second slice SL2 may be approximately <NUM><NUM>. Thus, in this configuration, a value of the cross-sectional area of the second slice SL2 is approximately <NUM> times less than a value of the cross-sectional area of the first slice SL1.

In the illustrated configuration, the gain of the ultrasonic tip <NUM> is approximately <NUM>. It should be appreciated that the ultrasonic tip <NUM> may exhibit a gain ranging between <NUM> and <NUM>, <NUM> and <NUM>, <NUM> and <NUM>, and <NUM> and <NUM>. Alternatively, the gain exhibited by the ultrasonic tip <NUM> may be below <NUM>. By comparison, similar ultrasonic tips known in the art that are used for similar applications have a gain of approximately <NUM>-<NUM>. The low gain of the of the ultrasonic tip <NUM>, which is calculated by dividing the ultrasonic tip <NUM> displacement by the ultrasonic handpiece <NUM> displacement, results in a reduction in stalling of the cutting portion <NUM> (e.g., cutting head <NUM>), which improves performance of the ultrasonic tip <NUM> overall. It also requires drawing less power to drive the ultrasonic tip <NUM> and allows for driving the ultrasonic tip <NUM> at a higher current, which may improve cutting rate without an increase in stalling of the cutting portion <NUM> (e.g., cutting head <NUM>).

Gain could also be achieved by a uniform outer surface and is composed of two different materials longitudinally aligned with each other such as described in <CIT>, entitled "Ultrasonic Torsional Tissue Dissection Utilizing Subaltern Modes of Longitudinal-Torsional Resonators".

The ultrasonic tip <NUM> may be free of a longitudinal to torsional motion conversion mechanism, and as such, configured to vibrate solely in the longitudinal direction. The ultrasonic tip <NUM> may consist of titanium.

The irrigation sleeve <NUM> described herein may be used with any type of ultrasonic tip. In other words, the irrigation sleeve <NUM> described herein may be used with ultrasonic tips that do not include the first and second bores <NUM>, <NUM> described. In addition, the irrigation sleeve <NUM> described herein may be used with ultrasonic tips that do not having a cutting head that have two substantially planar sides. For example, the irrigation sleeve <NUM> described herein may be used with ultrasonic tips that have cylindrical shapes and that rely on longitudinal, torsion, or longitudinal and torsional motion, such as those described in <CIT>, <CIT>, <CIT>.

The instrument described herein may be used with any of the tip configurations and/or any of the irrigation sleeve configurations described herein.

Claim 1:
An irrigation sleeve (<NUM>) for an ultrasonic surgical assembly (<NUM>), the ultrasonic surgical assembly (<NUM>) comprising a housing (<NUM>) having a proximal portion (<NUM>) and a distal portion (<NUM>), a transducer (<NUM>) at least partially disposed within the housing (<NUM>), a horn (<NUM>) coupled to the transducer (<NUM>), and an ultrasonic tip (<NUM>) comprising a shaft (<NUM>), the ultrasonic tip (<NUM>) removably coupled to the horn (<NUM>), the irrigation sleeve (<NUM>) comprising:
a body (<NUM>) having a distal region and a proximal region;
a sheath (<NUM>) coupled to and disposed over a portion of said body (<NUM>), said sheath (<NUM>) having a proximal end and an opposing distal end; and
an irrigation conduit (<NUM>) for conveying irrigation fluid,
the irrigation conduit (<NUM>) defining an inlet aperture (<NUM>) disposed at the proximal region of said body (<NUM>), and an outlet aperture (<NUM>), wherein the irrigation fluid is configured to enter the irrigation conduit (<NUM>) at the inlet aperture (<NUM>) and exit the irrigation conduit (<NUM>) at the outlet aperture (<NUM>);
characterized in that
the body (<NUM>) is releasably coupleable to the distal portion (<NUM>) of the housing (<NUM>), said body (<NUM>) defining a helical groove (<NUM>) which at least partially surrounds the shaft (<NUM>) of the ultrasonic tip (<NUM>) when the body (<NUM>) is coupled to the distal portion (<NUM>) of the housing (<NUM>) such that the ultrasonic tip (<NUM>) is in a lumen (<NUM>) defined by the irrigation sleeve (<NUM>);
the sheath (<NUM>) is coupled to and disposed over a portion of said body (<NUM>) to surround at least a full revolution of the helical groove (<NUM>); and
the irrigation conduit (<NUM>) is disposed within said helical groove (<NUM>), wherein the outlet aperture (<NUM>) is disposed at a distal region of said body (<NUM>).