Patent Description:
As medical professionals strive to reduce the size of the incisions and the amount of recovery time required following surgical procedures, the sizes of medical instruments used in such procedures have become smaller. Medical instruments utilized in performing such surgical 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. The cutting accessories may also be used in coordination with irrigation or aspiration, that is, suction, to reduce heat and/or remove debris at the surgical site. Irrigation may also be utilized as a cutting medium.

Document <CIT> describes an ultrasound type treatment apparatus including an inner sheath covering an ultrasonic transmission member having a first suction passage and defining a space relative to the ultrasound transmission member and an outer sheath covering the inner sheath and defining a space relative to the inner sheath. In the treatment apparatus, a liquid medium supply passage is provided at one of the space between the ultrasound transmission member and the inner sheath and space between the inner sheath and the outer sheath to supply a liquid medium to the distal end of the ultrasound transmission member. A second suction passage is formed at the other of the space between the ultrasound transmission member and the inner sheath and space between the inner sheath and the outer sheath. The first suction passage is connected by a suction tube to the second suction passage.

The invention is defined in the independent claim and other embodiments are listed in the dependent claims.

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.

An ultrasonic tip as defined in claim <NUM> is for use with a surgical handpiece to produce both longitudinal and torsional motion. The handpiece includes an ultrasonic transducer disposed within a housing. The ultrasonic tip comprises a shaft, a cutting feature, and a protrusion. The shaft has a longitudinal axis extending between a proximal end and a distal end of the shaft. The proximal end has a first diameter. The distal end has a second diameter. The first diameter is greater than the second diameter. The shaft comprises a vibration conversion mechanism for converting a vibration energy transmitted from the ultrasonic transducer into a composite vibration composed of a longitudinal vibration along the longitudinal axis and a torsional vibration. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft. The aspiration lumen is configured to extend along the longitudinal axis of the shaft. The aspiration lumen is configured to be placed in fluid communication with the handpiece. The protrusion is on the shaft and is positioned between the distal end and the proximal end. The protrusion is positioned distal to the vibration conversion mechanism along the longitudinal axis. A portion of the protrusion has a third diameter. The third diameter is less than the first diameter and the third diameter is greater than the second diameter. An aperture is defined by the protrusion. The aperture is in fluid communication with the aspiration lumen. The protrusion reinforces an area surrounding the aperture.

The proximal end of the shaft may comprise a coupling feature configured to removeably couple the shaft to the transducer of the handpiece.

The coupling feature may comprise a plurality of threads configured to couple to the transducer of the handpiece.

The vibration conversion mechanism may comprise one or more helical groove portions formed on an external surface of the shaft.

An axis of the aperture may be transverse to the longitudinal axis of the ultrasonic tip.

The cutting feature may comprise a cutting face facing in a direction at an angle equal to or less than <NUM> degrees to the longitudinal axis.

The cutting feature may have a cutting face arranged radially outward from the longitudinal axis. The cutting face may comprise one or more teeth.

The protrusion may comprise a first taper region, a median region, and a second taper region. An external surface of the median region may be generally parallel to the longitudinal axis. The median region may be disposed between the first taper region and the second taper region. The first taper region may be proximal to the median region and have a positive slope. The second taper region may be distal to the median region and have a negative slope.

The aspiration lumen may be open at the distal end and at the proximal end of the shaft.

An ultrasonic sleeve assembly is for use with a surgical handpiece comprising an ultrasonic transducer is defined in claim <NUM>. The ultrasonic sleeve assembly comprises a cutting tip and an irrigation sleeve. The cutting tip comprises a shaft, a vibration conversion mechanism, a cutting feature and a protrusion. The shaft extends between a proximal end and a distal end. The proximal end comprises a coupling feature configured to removeably couple the shaft to the handpiece. The proximal end comprises a first diameter and the distal end comprises a second diameter. The first diameter is greater than the second diameter. The vibration conversion mechanism is for converting a vibration energy transmitted from the ultrasonic transducer into a composite vibration composed of a longitudinal vibration along a longitudinal axis and a torsional vibration. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft and is configured to extend along the longitudinal axis of the shaft. The aspiration lumen is configured to be in fluid communication with the surgical handpiece when the shaft is coupled to the surgical handpiece. The protrusion is on the shaft and is positioned distal of the vibration conversion mechanism. A portion of the protrusion has a third diameter. The third diameter is less than the first diameter. The third diameter is greater than the second diameter. The protrusion is configured to strengthen the shaft. An aperture is defined by the protrusion and is in fluid communication with the aspiration lumen. The irrigation sleeve is configured to surround a portion of the shaft when the irrigation sleeve and the cutting tip are coupled to the handpiece. The irrigation sleeve defines a lumen comprising a proximal end and a distal end. The proximal end of the lumen comprises a coupling mechanism configured to removeably couple to the handpiece. The irrigation sleeve further defines an irrigation channel separate from the lumen. The irrigation channel has a distal end and a proximal end. The proximal end of the irrigation channel is configured to releasably couple to an irrigation source. The irrigation channel is configured to carry fluid to the lumen through an irrigation port. The irrigation port is in fluid communication with the irrigation channel and the lumen.

The cutting feature may comprise a cutting face facing in a direction perpendicular to the longitudinal axis.

The aperture may be positioned in a radially opposed direction from the cutting face.

The protrusion may comprise a first taper region, a median region, and a second taper region. An external surface of the median region may be generally parallel to the longitudinal axis. The median region may be disposed between the first taper region and the second taper region. The first taper region may be proximal to the median region and may have a positive slope. The second taper region may be distal to the median region and may have a negative slope.

The aspiration lumen may be open at the distal end and the proximal end of the shaft.

An ultrasonic cutting system for producing both longitudinal and torsional motion is defined in claim <NUM> and comprises a handpiece, a cutting tip and an irrigation sleeve. The handpiece comprises a transducer disposed within a housing. The cutting tip is coupled to the handpiece and comprises a shaft and a cutting feature. The shaft comprises a distal end and a proximal end. The proximal end comprises a coupling feature configured to removeably couple the shaft to the handpiece. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft. The aspiration lumen is configured to extend along a longitudinal axis of the shaft. The aspiration lumen is in fluid communication with the handpiece. An aperture is in fluid communication with the aspiration lumen, and is located between the proximal end and the distal end of the shaft. The aperture has a proximal end and a distal end. An irrigation sleeve is coupled to the handpiece. The irrigation sleeve surrounds a portion of the shaft, and has a proximal end and a distal end. The irrigation sleeve defines a lumen. The proximal end of the irrigation sleeve has a coupling mechanism configured to removeably couple the irrigation sleeve to the handpiece. The irrigation sleeve further defines an irrigation channel comprising a distal end and a proximal end. The proximal end of the irrigation channel is configured to receive irrigation fluid from an irrigation source. An irrigation port is in fluid communication with the distal end of the irrigation channel. The irrigation port is configured to dispense irrigation fluid toward the shaft. The distal end of the irrigation sleeve is positioned proximal to the distal end of the shaft. The irrigation port is positioned proximal relative to the aperture along the longitudinal axis. The distal end of the irrigation sleeve is distal to the distal end of the aperture such that the irrigation sleeve encompasses an entirety of the aperture.

The distal end of the irrigation sleeve may extend beyond the distal end of the aperture in a distal direction along the longitudinal axis.

The shaft may comprise a vibration conversion mechanism for converting a vibration energy transmitted from the transducer into a composite vibration composed of a longitudinal vibration along the longitudinal axis and a torsional vibration.

The cutting feature may have a cutting face arranged radially outward from the longitudinal axis and wherein the cutting face comprises one or more teeth.

An ultrasonic tip according to an exemplary embodiment is for use with a surgical handpiece to produce both longitudinal and torsional motion, the surgical handpiece including an ultrasonic transducer. The ultrasonic tip comprises a shaft, a cutting feature and a protrusion. The shaft extends between a proximal end and a distal end. The proximal end has a first cross-sectional area and a second cross-sectional area. The first cross-sectional area is greater than the second cross-sectional area. The shaft comprises a vibration conversion mechanism for converting a vibration energy transmitted from the ultrasonic transducer into a composite vibration composed of a longitudinal vibration along a longitudinal axis and a torsional vibration. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft. The aspiration lumen is configured to extend along the longitudinal axis of the shaft. The aspiration lumen is configured to be placed in fluid communication with the handpiece. The protrusion is on the shaft and is positioned between the distal end and the proximal end. The protrusion is positioned distal to the vibration conversion mechanism along the longitudinal axis. A portion of the protrusion has a third cross-sectional area. The third cross-sectional area is less than the first cross-sectional area. The third cross-sectional area is greater than the second cross-sectional area. An aperture is defined by the protrusion and is in fluid communication with the aspiration lumen. The protrusion reinforces an area surrounding the aperture.

An ultrasonic tip according to another exemplary embodiment is for use with a surgical handpiece that includes an ultrasonic transducer disposed within a housing. The ultrasonic tip comprises a shaft, a cutting feature and a protrusion. The shaft comprises a distal region, an intermediate region and a proximal region. The intermediate region has a first diameter. The distal region has a second diameter. The first diameter is greater than the second diameter. The shaft comprises a vibration conversion mechanism for converting a vibration energy transmitted from the ultrasonic transducer into a composite vibration composed of a longitudinal vibration along a longitudinal axis and a torsional vibration. The cutting feature is coupled to the distal region of the shaft. A first lumen is defined by the shaft. The first lumen is configured to extend along the longitudinal axis of the shaft. The first lumen is configured to be placed in fluid communication with the handpiece. The protrusion is on the shaft and is positioned between the intermediate region and the distal region. The intermediate region is positioned between the protrusion and the vibration conversion mechanism. A portion of the protrusion has a third diameter. The third diameter is less than the first diameter, and the third diameter is greater than the second diameter. An aperture is defined by the protrusion The aperture is in fluid communication with the first lumen. The protrusion reinforces an area surrounding the aperture.

An ultrasonic tip according to another exemplary embodiment is for use with a surgical handpiece to produce both longitudinal and torsional motion, the handpiece including an ultrasonic transducer. The ultrasonic tip comprises a shaft, a cutting feature and a protrusion. The shaft extends between a proximal end and a distal end. The proximal end has a first cross-sectional area. The distal end has a second cross-sectional area. The first cross-sectional area is greater than the second cross-sectional area. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft. The aspiration lumen is configured to extend along a longitudinal axis of the shaft. The aspiration lumen is configured to be placed in fluid communication with the handpiece. The protrusion is on the shaft and is positioned between the distal end and the proximal end. A portion of the protrusion has a third cross-sectional area. The third cross-sectional area is less than the first cross-sectional area. The third cross-sectional area is greater than the second cross-sectional area. An aperture is defined by the protrusion and in fluid communication with the aspiration lumen. The protrusion reinforces an area surrounding the aperture.

An ultrasonic tip according to another exemplary embodiment is for use with a surgical handpiece to produce both longitudinal and torsional motion, the handpiece including an ultrasonic transducer disposed within a housing. The ultrasonic tip comprises a shaft, a cutting feature and a protrusion. The shaft has a longitudinal axis extending between a proximal end and a distal end. The proximal end has a first diameter and the distal end has a second diameter. The first diameter is greater than the second diameter. The cutting feature is coupled to the distal end of the shaft. An aspiration lumen is defined by the shaft. The aspiration lumen is configured to extend along the longitudinal axis of the shaft. The aspiration lumen is configured to be placed in fluid communication with the handpiece. The protrusion is on the shaft and is positioned between the distal end and the proximal end. A portion of the protrusion has a third diameter. The third diameter is less than the first diameter. The third diameter is greater than the second diameter. An aperture is defined by the protrusion and is in fluid communication with the aspiration lumen. The protrusion reinforces an area surrounding the aperture.

<FIG> and <FIG> illustrate an exemplary configuration of an ultrasonic surgical handpiece assembly <NUM>, which may comprise part of an ultrasonic cutting system <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 proximal housing portion <NUM> and a distal 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>, alternatively identified herein as a cutting 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>, which may be an ultrasonic 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 piezoelectric element or a magnetostrictive element 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> for fluid connection to a nipple <NUM> at a proximal end <NUM> of the proximal housing portion <NUM>. The nipple <NUM> may be used to connect the handpiece <NUM> to a vacuum source (not shown). The horn lumen <NUM> may define a portion of a passageway that extends through the ultrasonic handpiece <NUM> to provide aspiration to the ultrasonic tip <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 <NUM> to the distal end of the ultrasonic handpiece <NUM>. The irrigation line <NUM> may serve to channel water from an irrigation system that is coupled to the ultrasonic handpiece <NUM> through the ultrasonic handpiece <NUM> to the irrigation sleeve <NUM>. It should be appreciated that the irrigation line <NUM> may route directly from an irrigation source (not shown) to the ultrasonic sleeve (i.e., the irrigation line need not be always routed through the handpiece).

The ultrasonic tip <NUM> may comprise a shaft <NUM> that comprises a distal region <NUM>, alternatively referenced to herein as a distal end <NUM>, an intermediate region <NUM>, and a proximal region <NUM>, alternatively reference to herein as a proximal region <NUM>. The shaft also has a distal end and a proximal end, with the proximal region being adjacent the proximal end and the distal region being adjacent the distal end. The ultrasonic tip 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 configured to engage a corresponding threaded coupler <NUM> 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.

The shaft <NUM> of the ultrasonic tip <NUM> may also be configured to define an aspiration lumen <NUM> that extends from the proximal region <NUM>, through the intermediate region <NUM>, to the distal region <NUM> of the ultrasonic tip <NUM>. The aspiration lumen <NUM> may be oriented to be generally parallel to and may extend along a longitudinal axis. The aspiration lumen <NUM> of the ultrasonic tip <NUM> may be configured to form a fluid passageway with the lumen <NUM> of the horn <NUM> when the ultrasonic tip <NUM> is coupled to the horn <NUM>. Otherwise stated, the aspiration lumen <NUM> may be configured to be placed in fluid communication with the handpiece <NUM>, and the lumen <NUM> of the horn <NUM> in particular. The aspiration lumen <NUM> is open at the distal region <NUM> of the shaft <NUM>. The aspiration lumen <NUM> of the ultrasonic tip <NUM> may be configured to provide aspiration away from the surgical site. For example, the aspiration lumen <NUM> may be used to vacuum fluid and biological tissue away from the distal end <NUM> of the ultrasonic tip <NUM>. The aspiration lumen <NUM> may be in fluid communication with a lumen defined by the cutting feature <NUM>.

<FIG> illustrates a top view of an exemplary configuration of the irrigation sleeve <NUM> having a distal end <NUM> and a proximal end. The irrigation sleeve <NUM> may comprise an irrigation sleeve coupling mechanism <NUM> on the proximal end of the irrigation sleeve <NUM>. The irrigation sleeve coupling mechanism <NUM> may comprise one or more fingers <NUM> extending proximally from the proximal end 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 the longitudinal axis <NUM> of the irrigation sleeve <NUM>. The fingers <NUM> act as the male fitting configured to couple with a female fitting (not shown) on the handpiece <NUM> to create a snap-fit <NUM> 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>. For example, the irrigation sleeve coupling mechanisms <NUM> may be configured as a threaded connection.

Referring to <FIG>, a sectional view of the ultrasonic tip <NUM> at least partially disposed within a lumen <NUM> defined by the irrigation sleeve <NUM> is illustrated. The irrigation sleeve <NUM> may comprise an irrigation channel <NUM> that has a proximal end and a distal end. The proximal end of the irrigation channel <NUM> may be configured to couple to the distal end of the irrigation line <NUM> of the ultrasonic handpiece <NUM> or irrigation source. The irrigation channel <NUM> may be configured to run adjacent to the lumen <NUM> defined by the irrigation sleeve <NUM> and terminating at a port <NUM> disposed on the surface of the lumen <NUM> to provide irrigation fluid from the ultrasonic handpiece <NUM> to the ultrasonic tip <NUM> and the surgical site. The position of the port <NUM> may vary. For example, the port <NUM> may be adjacent the proximal end of the sleeve <NUM>. Alternatively, the position of the port may be adjacent the distal end of the sleeve.

Referring to <FIG>, a portion of the distal region of the ultrasonic tip <NUM> is illustrated. The shaft <NUM> of the ultrasonic tip <NUM> may comprise a protrusion <NUM> at an intermediate point on the shaft <NUM> between the proximal region <NUM> and the distal region <NUM> of the ultrasonic tip <NUM>. The protrusion <NUM> may be configured to extend radially about the shaft <NUM> of the ultrasonic tip <NUM>. The protrusion <NUM> may comprise a first taper region <NUM>, a median region <NUM>, and a second taper region <NUM>. The median region <NUM> is positioned between the first taper region <NUM> and the second taper region <NUM>. In an exemplary configuration, the first taper region <NUM> may have a positive slope on the proximal side of the protrusion <NUM>, and the second taper region <NUM> may have a negative slope on the distal side of said protrusion <NUM> relative to the longitudinal axis of the lumen of the shaft. The median region <NUM> may have no slope and may be parallel with respect to the longitudinal axis <NUM>. In another configuration, the protrusion <NUM> may comprise a generally rounded or hemispherical geometry at the transition from the first taper region <NUM> to the median region <NUM> and then the second taper region <NUM>. The diameter and cross-sectional area of the first taper region <NUM> and the second taper region <NUM> is less than the diameter and cross-sectional area of the median region <NUM>. In another configuration, the protrusion <NUM> may comprise other multifaceted shapes, not shown. The protrusion <NUM> may be configured to have a progressive transition from the first taper region <NUM> to the median region <NUM> and then from the median region <NUM> to the second taper region <NUM>. The progressive transition of the protrusion <NUM> may reduce the likelihood of creating an additional stress point in the shaft <NUM> that may have a higher probability of failure during ultrasonic vibration. Additionally, the progressive transition prevents disturbances of the fluid flow patterns about the ultrasonic tip <NUM> as the fluid moves distally <NUM> relative to the ultrasonic tip <NUM> from between the irrigation sleeve <NUM> and the ultrasonic tip <NUM> from the irrigation port <NUM>. The progressive transition also allows for the ultrasonic tip <NUM> to be used at high power without experiencing high stress to the point that could cause breakage of the ultrasonic tip <NUM>. The progressive transition may also improve the properties of the shaft <NUM> to allow the ultrasonic tip <NUM> to be operated at optimal frequencies.

The shaft <NUM> may be free from any abrupt steps from the length associated with diameter D4 to the length associated with diameter D5 and/or the length associated with diameter D3 to the length associated with D5. Free from any abrupt steps should mean that the angle of the slope of each of the transition regions is lower than <NUM>, or <NUM> degrees relative to the external surface of the shaft <NUM>.

The ultrasonic tip <NUM> may further comprise the aperture <NUM> in the shaft <NUM>. The protrusion <NUM> defines the aperture <NUM>, typically in the median region <NUM> of the protrusion <NUM>. The aperture <NUM> is in fluid communication with the aspiration lumen <NUM>. The axis of the aperture <NUM> may be transverse to the longitudinal axis <NUM> of the ultrasonic tip <NUM>. In one configuration, the axis of the aperture <NUM> may be perpendicular to the longitudinal axis <NUM>. The diameter of the aperture <NUM> is smaller than the diameter of the aspiration lumen <NUM>.

The protrusion <NUM> reinforces the area of the shaft <NUM> near the aperture <NUM>. Because the aperture <NUM> otherwise weakens the strength of the shaft <NUM> by the aperture <NUM>, a thicker third diameter D3 of the shaft <NUM> at the protrusion <NUM> and may help to increase the structural integrity of the ultrasonic tip <NUM> when the ultrasonic tip <NUM> is subjected to ultrasonic movements in the torsional and longitudinal directions during use.

The cutting feature <NUM> and an aspiration lumen opening <NUM> may be positioned at the distal end of the shaft <NUM>. <FIG> illustrate the aspiration lumen opening <NUM> being open on the distal region <NUM> of the shaft <NUM> and/or cutting feature <NUM>. The aspiration lumen opening <NUM> may be used to remove excess fluid and/or biological debris from the surgical site.

In certain configurations, the dimension of the protrusion <NUM> are configured based on the dimensions of the aperture <NUM>. For example, the axial length of the median region <NUM> may be between <NUM>-<NUM> % larger than the diameter of the aperture <NUM>. In other configurations, the axial length of the median region <NUM> may be between <NUM>-<NUM>% larger than the diameter of the aperture <NUM>. Similarly, the length of the first and second tapered regions (<NUM>, <NUM>) may also be related to the diameter of the aperture <NUM>. For example, the combined axial length of the first tapered region <NUM>, the median region <NUM>, and the second tapered region <NUM> may be between <NUM> and <NUM> % larger than the diameter of the aperture <NUM>. These dimensions ensure that the tip achieves the precise balance of stress reduction and cutting performance.

For example, the length of the protrusion <NUM> (i.e., the distance between the line at 6E and 6F in <FIG>) may be approximately <NUM>, and could be between <NUM> and <NUM> in other configurations. The axial length (from the length at D4 to the length at D5) and radial thickness of the protrusion <NUM> may be related to the amount of material removed to create the aperture. For example, if the aperture <NUM> were to have a larger diameter, the diameter of the protrusion <NUM> and thickness would be greater. Conversely, if the aperture <NUM> were to have a smaller diameter, the thickness and length of the protrusion <NUM> would be less.

<FIG> and <FIG> show the ultrasonic tip <NUM> comprising the shaft <NUM> and a protrusion <NUM> on the shaft <NUM> positioned between the distal region <NUM> and the proximal region <NUM>. The protrusion <NUM> is positioned distal to the vibration conversion mechanism <NUM> along the longitudinal axis <NUM>, as shown in <FIG>. The shaft <NUM> at the protrusion <NUM> may have a third diameter D3 that is less than the first diameter D1 at the intermediate region <NUM> and greater than the second diameter D2 at the distal region <NUM>.

As illustrated in <FIG>, the diameter of the ultrasonic tip <NUM> varies from the proximal region <NUM>, through the intermediate region <NUM>, to the distal region <NUM> of the shaft <NUM>. The shaft <NUM> comprises a first diameter D1 and comprises a second diameter D2, wherein the first diameter D1 is greater than the second diameter D2. The diameter D1 is positioned in the intermediate region <NUM> of the shaft <NUM> and the diameter D2 is positioned in the distal region <NUM> of the shaft.

The shaft <NUM> may be generally tapered along the longitudinal axis <NUM> from the proximal region <NUM>, through the intermediate region <NUM>, to the distal region <NUM>. For example, the diameter of the shaft <NUM> may become smaller distally along the shaft <NUM> from the proximal region <NUM> to the distal region <NUM>. One of a number of advantages provided by a tapered shaft <NUM>, as it may reduce the size of the tip proximate and improve the user's line of sight while using the ultrasonic tip <NUM>.

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 example of the shaft <NUM>, and ultrasonic tip <NUM> may be integral, unitary, and one-piece. In another example, the distal end <NUM> of the ultrasonic tip <NUM> may be attached to the shaft <NUM> by a suitable mechanism such as threads (not shown). It should be appreciated that metals are known in the art regarding high power ultrasonic components. It should also be appreciated that the diameters of the distal region <NUM> of the shaft <NUM> and the ultrasonic tip <NUM> have a relatively small diameter, for example less than one centimeter (<NUM>), so as to work in a small opening of the patient. It should further be appreciated that the shaft <NUM> and the ultrasonic tip <NUM> may be scaled larger or smaller depending on the application.

Referring to <FIG>, the ultrasonic tip <NUM> further comprises a vibration conversion mechanism <NUM> for converting a vibration energy transmitted from the ultrasonic transducer <NUM> into a composite vibration composed of a longitudinal vibration along a longitudinal axis <NUM> and a torsional vibration. The intermediate region <NUM> is distal the vibration conversion mechanism <NUM>. The vibration conversion mechanism <NUM> may comprise one or more helical groove portions <NUM> on the surface of the shaft <NUM>. These one or more groove portions <NUM> may be wound around a circumferential surface of the shaft <NUM>, as shown. The vibration conversion mechanism <NUM> functions to convert the longitudinal vibration transmitted from the transducer <NUM> through the horn <NUM> into a composite vibration composed of a longitudinal vibration in the longitudinal axial <NUM> direction of the ultrasonic tip <NUM> and a torsional vibration having the longitudinal axis <NUM> of the ultrasonic tip <NUM> act as a fulcrum. It should be appreciated that the vibration conversion mechanism may alternatively take other forms suitable for converting a longitudinal motion into a composite motion. These alternative forms may be asymmetries in the cross-section shape of the shaft <NUM>. Details regarding the vibration conversion mechanism may be found in <CIT>;<CIT>; and <CIT>.

<FIG> also shows the ultrasonic tip <NUM> comprising the shaft <NUM> and a cutting feature <NUM> coupled to the distal region <NUM> of the shaft <NUM>. The cutting feature <NUM> may be the part of the ultrasonic tip <NUM> that dissects or cuts a patient's biological tissue. A range of different cutting features <NUM> may be coupled to the distal end <NUM> of the shaft <NUM>. In one example, the cutting feature <NUM> may have a cutting face <NUM> facing in a direction at an angle equal to or less than <NUM> degrees relative to the longitudinal axis <NUM>. The terms cutting face and cutting surface may be used interchangeably herein. The cutting face <NUM> may be positioned in a manner that the center of the cutting face <NUM> is on an opposing side of the shaft <NUM> relative to the aperture <NUM>. The cutting feature may be configured to cut with torsional motion.

As shown in <FIG>, the shaft <NUM> may have a greater cross sectional area on the intermediate region <NUM> at location D1 than a cross sectional area at location D2. <FIG> shows the cross sectional area of the shaft <NUM> at location D1. <FIG> shows the cross sectional area of the shaft <NUM> at D2. Furthermore, <FIG> shows the cross sectional area of the shaft <NUM> at location D3 and also shows the aperture <NUM>. As shown in <FIG>, the cross sectional area of D4 is less than the cross sectional area of D3. <FIG> shows the cross sectional area at location D5. When taking <FIG> together, this shows that the cross sectional area at location D3, which is near the protrusion <NUM>, is greater than the cross sectional area at locations D4 and D5 which are proximally and distally adjacent to the protrusion, respectfully. The various cross-sectional area of the shaft <NUM> results in different strengths of the shaft <NUM> at various locations along the length. Generally, the greater cross-sectional area of the shaft <NUM> at a given location results in a greater wall thickness, which results in a greater strength.

As described above, the aperture <NUM> weakens the strength of the shaft <NUM>. The greater cross sectional area at the protrusion <NUM> overcomes the weakness created by the aperture <NUM> to allow the ultrasonic tip <NUM> to be used at a higher power setting and not break from the increased stress. The cross sectional area of the protrusion <NUM> may be configured to have the least amount of area necessary to avoid inefficiencies and maintain line of sight, while maintaining necessary stress properties to prevent failure.

As shown in <FIG>, the shaft <NUM> of the ultrasonic tip <NUM> has varying thicknesses. Assuming the aspiration lumen <NUM> has a constant diameter from the distal region <NUM>, through the intermediate region <NUM>, to the proximal region <NUM>, the thickness of shaft <NUM> at the aperture <NUM> is greater than the thickness of the shaft <NUM> at areas immediately adj acent to the aperture. Said another way, the shaft <NUM> thickness at the median region <NUM> is greater than the shaft <NUM> thickness at the first taper region <NUM> and the second taper region <NUM>. The increased thickness of the shaft <NUM> at the median region <NUM> where the aperture <NUM> is located may improve the strength of the shaft <NUM>.

As shown in <FIG>, the irrigation sleeve <NUM> is configured to surround a portion of the shaft <NUM> in when the irrigation sleeve <NUM> and the ultrasonic tip <NUM> are coupled to the handpiece <NUM>. The irrigation sleeve <NUM> comprises the lumen <NUM>. The irrigation sleeve <NUM> has a proximal end <NUM> and the distal end <NUM>. The proximal end <NUM> of the sleeve <NUM> includes the coupling mechanism <NUM> configured to removeably couple to the handpiece <NUM>. The irrigation sleeve defines an irrigation channel <NUM> and is separate from the lumen <NUM>. The irrigation channel <NUM> has a distal end and a proximal end, the proximal end of the irrigation channel <NUM> is configured to releasably couple to the irrigation source (not shown). The irrigation channel <NUM> may carry fluid to the lumen <NUM> through an irrigation port <NUM>. The irrigation port <NUM> may be in fluid communication with the irrigation channel <NUM> and the lumen <NUM>.

In certain configurations, the fluid may flow from the irrigation source (not shown) through the irrigation channel <NUM> to the irrigation port <NUM>. The irrigation port <NUM> supplies fluid to the lumen <NUM> of the irrigation sleeve <NUM>. Fluid in the lumen <NUM> of the irrigation sleeve <NUM> may flow distally towards the cutting tip <NUM>. While the fluid is flowing toward the cutting tip <NUM> some fluid may enter the aspiration lumen <NUM> through the aperture <NUM> on the protrusion <NUM>. The fluid flowing through the aperture <NUM> helps to reduce the temperature of the cutting tip <NUM> and may increase performance of the surgical handpiece assembly <NUM>. Furthermore, it may alternatively help reduce the temperature of the sleeve <NUM>, to thereby prevent tissue that comes into contact with the exterior surface of the sleeve from being inadvertently heated.

The irrigation sleeve <NUM> may be made from any polymer, for example a thermoplastic. The distal end <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>.

The irrigation channel <NUM> may be in fluid communication with the handpiece <NUM> and/or an irrigation source (not shown). The combination of the aperture <NUM> on the shaft <NUM>, the irrigation channel <NUM>, the position of the distal end <NUM> of the sleeve <NUM> relative to the aperture <NUM>, the irrigation port <NUM> and the aspiration lumen <NUM> improve the cooling ability of the ultrasonic tip <NUM>. Additionally, the above referenced combination improves cooling of the ultrasonic tip <NUM> to prevent the irrigation sleeve <NUM> from becoming deformed or melting from excessive heat generated by the longitudinal and torsional motion of the ultrasonic tip <NUM>.

As shown in <FIG>, the irrigation sleeve <NUM> surrounds a portion of the ultrasonic tip <NUM> along the length of the ultrasonic tip. The distal end <NUM> of the irrigation sleeve <NUM> extends along the longitudinal axis <NUM> towards the distal region <NUM> of the ultrasonic tip <NUM>. The distal end <NUM> of the irrigation sleeve <NUM> may extend beyond the aperture <NUM>. The aperture <NUM> may have a proximal end and a distal end, the distal end <NUM> of the irrigation sleeve <NUM> extends beyond both the proximal side and the distal side of the aperture <NUM>. In other words, the aperture <NUM> is completely covered by the sleeve <NUM> when the ultrasonic tip and the sleeve <NUM> are coupled to the handpiece <NUM>. The fluid in the lumen <NUM> helps cool the ultrasonic tip <NUM> and the sleeve <NUM>.

The ultrasonic tip <NUM> allows the efficient removal of bone with torsional or longitudinal motion of the instrument tip. The cutting feature <NUM> may comprise a cutting face 64A to aid in such removal. However, it should be appreciated that the ultrasonic tip <NUM> may also be used with transducers that vibrate longitudinally, torsionally, or a combination of both longitudinal and torsional motion. Furthermore, in some examples, the ultrasonic tip is free from the vibration conversion mechanism.

A torsional dissection tip is effective in the removal of bone, bony prominences, calcified neoplasm, cartilage, cartilaginous materials, intervertebral disc, and other pathologies when the cutting feature contacts such. The device is especially useful during neurosurgery, especially inside-out bone dissection once the superficial cortex has been removed, spinal surgery, orthopedic surgery, plastic/reconstructive surgery, and ear, nose, throat surgery, and other surgeries whereby the aforesaid tissues are encountered.

It is to be appreciated that the cutting features <NUM> of the ultrasonic tip <NUM> may have a plurality of configurations. Referring to <FIG>, various exemplary configurations of the cutting feature <NUM> of the ultrasonic tip <NUM> are illustrated. The cutting feature <NUM> may comprise a cutting face <NUM>, wherein the cutting face <NUM> comprises one or more teeth <NUM>. The teeth <NUM> of the cutting face <NUM> may be arranged wherein the teeth <NUM> are directed radially outward from the longitudinal axis <NUM> of the ultrasonic tip <NUM>. For certain configurations, the plane of the cutting feature is substantially parallel yet offset to the central axis of the distal end <NUM> of the instrument, however the position of the cutting face <NUM> can be varied in a virtually limitless manner.

Referring to <FIG>, a first configuration of the cutting feature <NUM> is illustrated. The first configuration of the cutting feature <NUM> comprises a cutting surface 64B that includes a plurality of teeth <NUM> disposed radially about the distal end <NUM> of the shaft <NUM>. For example, the teeth <NUM> may configured to be directed outwardly from the longitudinal axis <NUM> of the ultrasonic tip <NUM>, and the teeth <NUM> arrange to encircle the entire circumference of the distal end of the shaft <NUM>. At least some of the teeth extend distally.

Alternatively, <FIG> illustrates a second configuration of the cutting feature <NUM>. The second configuration of the cutting feature <NUM> comprises a cutting surface 64C comprising an arched or half cylinder-like shape that includes a plurality of teeth <NUM> directed outwardly from the longitudinal axis of the ultrasonic tip <NUM>.

<FIG> illustrates a third configuration of the cutting feature <NUM>. The third configuration of the cutting feature <NUM> comprises a cutting surface 64D comprising an arched or half cylinder-like shape that includes a plurality of teeth <NUM> directed outwardly from the longitudinal axis of the ultrasonic tip <NUM>. The cutting surface 64D is generally offset from the shaft <NUM> of the ultrasonic tip <NUM> and oriented to be perpendicular to the longitudinal axis <NUM> of the ultrasonic tip <NUM>.

<FIG> illustrates a fourth configuration of the cutting feature <NUM>. The fourth configuration of the cutting feature <NUM> comprises a cutting surface 64E comprising an arched or half cylinder-like shape that includes a plurality of teeth <NUM> directed outwardly from the longitudinal axis of the ultrasonic tip <NUM>. The cutting surface 64E is generally offset from the shaft of the ultrasonic tip <NUM> and oriented to be perpendicular to the longitudinal axis <NUM> of the ultrasonic tip <NUM>. Other suitable cutting features are also contemplated, including those described in ET. Patent No. <CIT>; and ET. Publication <CIT>.

Several examples have been discussed in the foregoing description. However, the examples discussed herein are not intended to be exhaustive or limit the invention to any particular form. For example, the ultrasonic tip may further include blades, drill bits, rotating burs, open-window shavers, and the like. The terminology which has been used is intended to be in the nature of words of description rather than of limitation.

Claim 1:
An ultrasonic tip (<NUM>) for use with a surgical handpiece (<NUM>) to produce both longitudinal and torsional motion, the handpiece (<NUM>) including an ultrasonic transducer (<NUM>) disposed within a housing (<NUM>, <NUM>), said ultrasonic tip (<NUM>) comprising:
a shaft (<NUM>) having a longitudinal axis (<NUM>) extending between a proximal end and a distal end, said proximal end having a first diameter (D1) and said distal end having a second diameter (D2), wherein said first diameter (D1) is greater than said second diameter (D2);
a cutting feature (<NUM>) coupled to said distal end of said shaft (<NUM>); and
an aspiration lumen (<NUM>) defined by said shaft (<NUM>), said aspiration lumen (<NUM>) configured to extend along said longitudinal axis (<NUM>) of said shaft (<NUM>), said aspiration lumen (<NUM>) configured to be placed in fluid communication with the handpiece (<NUM>);
characterized in that
said shaft (<NUM>) comprises a vibration conversion mechanism (<NUM>) for converting a vibration energy transmitted from the ultrasonic transducer (<NUM>) into a composite vibration composed of a longitudinal vibration along the longitudinal axis (<NUM>) and a torsional vibration;
and in that the ultrasonic tip (<NUM>) further comprises:
a protrusion (<NUM>) on said shaft (<NUM>) and positioned between said distal end and said proximal end with said protrusion (<NUM>) being positioned distal to said vibration conversion mechanism (<NUM>) along said longitudinal axis (<NUM>), a portion of said protrusion (<NUM>) having a third diameter (D3), wherein said third diameter (D3) is less than said first diameter (D1) and said third diameter (D3) is greater than said second diameter (D2); and
an aperture (<NUM>) defined by said protrusion (<NUM>) in fluid communication with said aspiration lumen (<NUM>), wherein said protrusion (<NUM>) reinforces an area surrounding the aperture (<NUM>).