Patent ID: 12226116

DETAILED DESCRIPTION

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 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 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 90 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. 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 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.

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

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

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

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

An ultrasonic tip 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 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 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 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.

FIGS.1and2illustrate an exemplary configuration of an ultrasonic surgical handpiece assembly10, which may comprise part of an ultrasonic cutting system12, that may be utilized by a medical professional to remove biological material from a patient. The ultrasonic surgical handpiece assembly10may comprise an ultrasonic handpiece11including a proximal housing portion22and a distal housing portion20. An irrigation sleeve24may be removably coupled to the distal housing portion20of the ultrasonic surgical handpiece11. The irrigation sleeve24and an ultrasonic tip26, alternatively identified herein as a cutting tip26, may be configured such that the irrigation sleeve24surrounds at least a portion of the ultrasonic tip26along a length of the ultrasonic tip26when both the irrigation sleeve24and the ultrasonic tip26are coupled to the ultrasonic handpiece11. The irrigation sleeve24and the ultrasonic tip26may at least in part comprise an ultrasonic sleeve assembly14.

FIG.2illustrates a sectional view of the ultrasonic surgical handpiece assembly10ofFIG.1. As illustrated inFIG.2, the ultrasonic handpiece11may comprise a transducer32, which may be an ultrasonic transducer32, disposed within a void defined by the distal housing portion20and the proximal housing portion22of the ultrasonic handpiece11. The transducer32may comprise a piezoelectric element or a magnetostrictive element configured to generate mechanical energy.

The ultrasonic handpiece11may also comprise a horn30that may be at least partially disposed within the void defined by the distal housing portion20and the proximal housing portion22of the ultrasonic handpiece11. The horn30may comprise a distal end and a proximal end. The proximal end of the horn30may be coupled to a distal end of the transducer32. The transducer32may be configured to provide the mechanical energy generated by the piezoelectric element or magnetostrictive element to the horn30. The horn30may also be configured to define a horn lumen31that extends from the distal end to the proximal end of the horn30for fluid connection to a nipple28at a proximal end16of the proximal housing portion22. The nipple28may be used to connect the handpiece11to a vacuum source (not shown). The horn lumen31may define a portion of a passageway that extends through the ultrasonic handpiece11to provide aspiration to the ultrasonic tip26.

The ultrasonic handpiece11may further comprise an irrigation line33that is disposed within the void defined by the distal housing portion20and the proximal housing portion22of the ultrasonic handpiece11. The irrigation line33may be configured to extend from the proximal end16to the distal end of the ultrasonic handpiece11. The irrigation line33may serve to channel water from an irrigation system that is coupled to the ultrasonic handpiece11through the ultrasonic handpiece11to the irrigation sleeve24. It should be appreciated that the irrigation line33may 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 tip26may comprise a shaft48that comprises a distal region50, alternatively referenced to herein as a distal end50, an intermediate region37, and a proximal region36, alternatively reference to herein as a proximal region36. 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 feature34positioned at the proximal region36of the shaft48and is configured to couple the proximal region36of the ultrasonic tip26to the distal end of the horn30to allow the horn30to be in mechanical communication with the ultrasonic tip26. The coupling feature34may be a threaded coupler configured to engage a corresponding threaded coupler35on the distal end of the horn30. The ultrasonic tip26may be threaded into the horn30and tightened to a predetermined torque specification to removably secure the ultrasonic tip26to the ultrasonic handpiece11. While not illustrated in the figures, it is contemplated that the coupling feature34may be configured as a quick connection, quarter turn fitting, or similar coupling mechanism. It is further contemplated that the coupling feature34may be configured to permanently affix the ultrasonic tip26to the handpiece11. For example, the ultrasonic tip26may be coupled to the ultrasonic handpiece11by a weld, epoxy, or similar coupling method. Alternatively, it is also contemplated that the ultrasonic tip26and the horn30may be formed as a unitary component.

The shaft48of the ultrasonic tip26may also be configured to define an aspiration lumen52that extends from the proximal region36, through the intermediate region37, to the distal region50of the ultrasonic tip26. The aspiration lumen52may be oriented to be generally parallel to and may extend along a longitudinal axis. The aspiration lumen52of the ultrasonic tip26may be configured to form a fluid passageway with the lumen31of the horn30when the ultrasonic tip26is coupled to the horn30. Otherwise stated, the aspiration lumen52may be configured to be placed in fluid communication with the handpiece11, and the lumen31of the horn30in particular. The aspiration lumen52is open at the distal region50of the shaft48. The aspiration lumen52of the ultrasonic tip26may be configured to provide aspiration away from the surgical site. For example, the aspiration lumen52may be used to vacuum fluid and biological tissue away from the distal end50of the ultrasonic tip26. The aspiration lumen52may be in fluid communication with a lumen defined by the cutting feature62.

FIG.3illustrates a top view of an exemplary configuration of the irrigation sleeve24having a distal end94and a proximal end. The irrigation sleeve24may comprise an irrigation sleeve coupling mechanism38on the proximal end of the irrigation sleeve24. The irrigation sleeve coupling mechanism38may comprise one or more fingers42extending proximally from the proximal end of the irrigation sleeve24. Each of the one or more fingers42may comprise a tab44extending in a radially outward direction relative to the longitudinal axis46of the irrigation sleeve24. The fingers42act as the male fitting configured to couple with a female fitting (not shown) on the handpiece11to create a snap-fit40or interference fit. It is contemplated that other types of irrigation sleeve coupling mechanisms38may be used to couple the irrigation sleeve24to the ultrasonic handpiece11. For example, the irrigation sleeve coupling mechanisms38may be configured as a threaded connection.

Referring toFIG.4, a sectional view of the ultrasonic tip26at least partially disposed within a lumen70defined by the irrigation sleeve24is illustrated. The irrigation sleeve24may comprise an irrigation channel88that has a proximal end and a distal end. The proximal end of the irrigation channel88may be configured to couple to the distal end of the irrigation line33of the ultrasonic handpiece11or irrigation source. The irrigation channel88may be configured to run adjacent to the lumen70defined by the irrigation sleeve24and terminating at a port92disposed on the surface of the lumen70to provide irrigation fluid from the ultrasonic handpiece11to the ultrasonic tip26and the surgical site. The position of the port92may vary. For example, the port92may be adjacent the proximal end of the sleeve24. Alternatively, the position of the port may be adjacent the distal end of the sleeve.

Referring toFIG.5, a portion of the distal region of the ultrasonic tip26is illustrated. The shaft48of the ultrasonic tip26may comprise a protrusion68at an intermediate point on the shaft48between the proximal region36and the distal region50of the ultrasonic tip26. The protrusion68may be configured to extend radially about the shaft48of the ultrasonic tip26. The protrusion68may comprise a first taper region76, a median region80, and a second taper region78. The median region80is positioned between the first taper region76and the second taper region78. In an exemplary configuration, the first taper region76may have a positive slope on the proximal side of the protrusion68, and the second taper region78may have a negative slope on the distal side of said protrusion68relative to the longitudinal axis of the lumen of the shaft. The median region80may have no slope and may be parallel with respect to the longitudinal axis46. In another configuration, the protrusion68may comprise a generally rounded or hemispherical geometry at the transition from the first taper region76to the median region80and then the second taper region78. The diameter and cross-sectional area of the first taper region76and the second taper region78is less than the diameter and cross-sectional area of the median region80. In another configuration, the protrusion68may comprise other multifaceted shapes, not shown. The protrusion68may be configured to have a progressive transition from the first taper region76to the median region80and then from the median region80to the second taper region78. The progressive transition of the protrusion68may reduce the likelihood of creating an additional stress point in the shaft48that may have a higher probability of failure during ultrasonic vibration. Additionally, the progressive transition prevents disturbances of the fluid flow patterns about the ultrasonic tip26as the fluid moves distally50relative to the ultrasonic tip26from between the irrigation sleeve24and the ultrasonic tip26from the irrigation port92. The progressive transition also allows for the ultrasonic tip26to be used at high power without experiencing high stress to the point that could cause breakage of the ultrasonic tip26. The progressive transition may also improve the properties of the shaft48to allow the ultrasonic tip26to be operated at optimal frequencies.

The shaft48may be free from any abrupt steps from the length associated with diameter D4to the length associated with diameter D5and/or the length associated with diameter D3to 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 10, or 5 degrees relative to the external surface of the shaft48.

The ultrasonic tip26may further comprise the aperture66in the shaft48. The protrusion68defines the aperture66, typically in the median region80of the protrusion68. The aperture66is in fluid communication with the aspiration lumen52. The axis of the aperture66may be transverse to the longitudinal axis46of the ultrasonic tip26. In one configuration, the axis of the aperture66may be perpendicular to the longitudinal axis46. The diameter of the aperture66is smaller than the diameter of the aspiration lumen52.

The protrusion68reinforces the area of the shaft48near the aperture66. Because the aperture66otherwise weakens the strength of the shaft48by the aperture66, a thicker third diameter D3of the shaft48at the protrusion68and may help to increase the structural integrity of the ultrasonic tip26when the ultrasonic tip26is subjected to ultrasonic movements in the torsional and longitudinal directions during use.

The cutting feature62and an aspiration lumen opening72may be positioned at the distal end of the shaft48.FIGS.8and9illustrate the aspiration lumen opening72being open on the distal region50of the shaft48and/or cutting feature62. The aspiration lumen opening72may be used to remove excess fluid and/or biological debris from the surgical site.

In certain configurations, the dimension of the protrusion68are configured based on the dimensions of the aperture66. For example, the axial length of the median region80may be between 200-1000% larger than the diameter of the aperture66. In other configurations, the axial length of the median region80may be between 500-800% larger than the diameter of the aperture66. Similarly, the length of the first and second tapered regions (76,78) may also be related to the diameter of the aperture66. For example, the combined axial length of the first tapered region76, the median region80, and the second tapered region78may be between 15000 and 24000% larger than the diameter of the aperture66. These dimensions ensure that the tip achieves the precise balance of stress reduction and cutting performance.

For example, the length of the protrusion68(i.e., the distance between the line at6E and6F inFIG.6A) may be approximately 2 mm, and could be between 1 mm and 6 mm in other configurations. The axial length (from the length at D4to the length at D5) and radial thickness of the protrusion68may be related to the amount of material removed to create the aperture. For example, if the aperture66were to have a larger diameter, the diameter of the protrusion68and thickness would be greater. Conversely, if the aperture66were to have a smaller diameter, the thickness and length of the protrusion68would be less.

FIGS.7and8show the ultrasonic tip26comprising the shaft48and a protrusion68on the shaft48positioned between the distal region50and the proximal region36. The protrusion68is positioned distal to the vibration conversion mechanism60along the longitudinal axis46, as shown inFIG.6A. The shaft48at the protrusion68may have a third diameter D3that is less than the first diameter D1at the intermediate region37and greater than the second diameter D2at the distal region50.

As illustrated inFIGS.6A-7, the diameter of the ultrasonic tip26varies from the proximal region36, through the intermediate region37, to the distal region50of the shaft48. The shaft48comprises a first diameter D1and comprises a second diameter D2, wherein the first diameter D1is greater than the second diameter D2. The diameter D1is positioned in the intermediate region37of the shaft48and the diameter D2is positioned in the distal region50of the shaft.

The shaft48may be generally tapered along the longitudinal axis46from the proximal region36, through the intermediate region37, to the distal region50. For example, the diameter of the shaft48may become smaller distally along the shaft48from the proximal region36to the distal region50. One of a number of advantages provided by a tapered shaft48, as it may reduce the size of the tip proximate and improve the user's line of sight while using the ultrasonic tip26.

The shaft48may 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 shaft48, and ultrasonic tip26may be integral, unitary, and one-piece. In another example, the distal end50of the ultrasonic tip26may be attached to the shaft48by 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 region50of the shaft48and the ultrasonic tip26have a relatively small diameter, for example less than one centimeter (1 cm), so as to work in a small opening of the patient. It should further be appreciated that the shaft48and the ultrasonic tip26may be scaled larger or smaller depending on the application.

Referring toFIG.6A, the ultrasonic tip26further comprises a vibration conversion mechanism60for converting a vibration energy transmitted from the ultrasonic transducer32into a composite vibration composed of a longitudinal vibration along a longitudinal axis46and a torsional vibration. The intermediate region37is distal the vibration conversion mechanism60. The vibration conversion mechanism60may comprise one or more helical groove portions71on the surface of the shaft48. These one or more groove portions71may be wound around a circumferential surface of the shaft48, as shown. The vibration conversion mechanism60functions to convert the longitudinal vibration transmitted from the transducer32through the horn30into a composite vibration composed of a longitudinal vibration in the longitudinal axial46direction of the ultrasonic tip26and a torsional vibration having the longitudinal axis46of the ultrasonic tip26act 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 shaft48. Details regarding the vibration conversion mechanism may be found in U.S. Pat. Nos. 6,497,715; 6,955,680; and 6,984,220; which are hereby incorporated in by reference in their entirety.

FIG.6Aalso shows the ultrasonic tip26comprising the shaft48and a cutting feature62coupled to the distal region50of the shaft48. The cutting feature62may be the part of the ultrasonic tip26that dissects or cuts a patient's biological tissue. A range of different cutting features62may be coupled to the distal end50of the shaft48. In one example, the cutting feature62may have a cutting face64facing in a direction at an angle equal to or less than 90 degrees relative to the longitudinal axis46. The terms cutting face and cutting surface may be used interchangeably herein. The cutting face64may be positioned in a manner that the center of the cutting face64is on an opposing side of the shaft48relative to the aperture66. The cutting feature may be configured to cut with torsional motion.

As shown inFIGS.6B-6F, the shaft48may have a greater cross sectional area on the intermediate region37at location D1than a cross sectional area at location D2.FIG.6Bshows the cross sectional area of the shaft48at location D1.FIG.6Cshows the cross sectional area of the shaft48at D2. Furthermore,FIG.6Dshows the cross sectional area of the shaft48at location D3and also shows the aperture66. As shown inFIG.6E, the cross sectional area of D4is less than the cross sectional area of D3.FIG.6Fshows the cross sectional area at location D5. When takingFIGS.6B-6Ftogether, this shows that the cross sectional area at location D3, which is near the protrusion68, is greater than the cross sectional area at locations D4and D5which are proximally and distally adjacent to the protrusion, respectfully. The various cross-sectional area of the shaft48results in different strengths of the shaft48at various locations along the length. Generally, the greater cross-sectional area of the shaft48at a given location results in a greater wall thickness, which results in a greater strength.

As described above, the aperture66weakens the strength of the shaft48. The greater cross sectional area at the protrusion68overcomes the weakness created by the aperture66to allow the ultrasonic tip26to be used at a higher power setting and not break from the increased stress. The cross sectional area of the protrusion68may 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 inFIG.8, the shaft48of the ultrasonic tip26has varying thicknesses.

Assuming the aspiration lumen52has a constant diameter from the distal region50, through the intermediate region37, to the proximal region36, the thickness of shaft48at the aperture66is greater than the thickness of the shaft48at areas immediately adjacent to the aperture. Said another way, the shaft48thickness at the median region80is greater than the shaft48thickness at the first taper region76and the second taper region78. The increased thickness of the shaft48at the median region80where the aperture66is located may improve the strength of the shaft48.

As shown inFIG.4, the irrigation sleeve24is configured to surround a portion of the shaft48in when the irrigation sleeve24and the ultrasonic tip26are coupled to the handpiece11. The irrigation sleeve24comprises the lumen70. The irrigation sleeve24has a proximal end36and the distal end94. The proximal end36of the sleeve24includes the coupling mechanism38configured to removeably couple to the handpiece11. The irrigation sleeve defines an irrigation channel88and is separate from the lumen70. The irrigation channel88has a distal end and a proximal end, the proximal end of the irrigation channel88is configured to releasably couple to the irrigation source (not shown). The irrigation channel88may carry fluid to the lumen70through an irrigation port92. The irrigation port92may be in fluid communication with the irrigation channel88and the lumen70.

In certain configurations, the fluid may flow from the irrigation source (not shown) through the irrigation channel88to the irrigation port92. The irrigation port92supplies fluid to the lumen70of the irrigation sleeve24. Fluid in the lumen70of the irrigation sleeve24may flow distally towards the cutting tip26. While the fluid is flowing toward the cutting tip26some fluid may enter the aspiration lumen52through the aperture66on the protrusion68. The fluid flowing through the aperture66helps to reduce the temperature of the cutting tip26and may increase performance of the surgical handpiece assembly10. Furthermore, it may alternatively help reduce the temperature of the sleeve24, to thereby prevent tissue that comes into contact with the exterior surface of the sleeve from being inadvertently heated.

The irrigation sleeve24may be made from any polymer, for example a thermoplastic. The distal end94of the irrigation sleeve24may have a portion of frangible sections that could be cut or snipped to change the length of the irrigation sleeve24.

The irrigation channel88may be in fluid communication with the handpiece11and/or an irrigation source (not shown). The combination of the aperture66on the shaft48, the irrigation channel88, the position of the distal end94of the sleeve24relative to the aperture66, the irrigation port92and the aspiration lumen52improve the cooling ability of the ultrasonic tip26. Additionally, the above referenced combination improves cooling of the ultrasonic tip26to prevent the irrigation sleeve24from becoming deformed or melting from excessive heat generated by the longitudinal and torsional motion of the ultrasonic tip26.

As shown inFIG.9, the irrigation sleeve24surrounds a portion of the ultrasonic tip26along the length of the ultrasonic tip. The distal end94of the irrigation sleeve24extends along the longitudinal axis46towards the distal region50of the ultrasonic tip26. The distal end94of the irrigation sleeve24may extend beyond the aperture66. The aperture66may have a proximal end and a distal end, the distal end94of the irrigation sleeve24extends beyond both the proximal side and the distal side of the aperture66. In other words, the aperture66is completely covered by the sleeve24when the ultrasonic tip and the sleeve24are coupled to the handpiece11. The fluid in the lumen70helps cool the ultrasonic tip26and the sleeve24.

The ultrasonic tip26allows the efficient removal of bone with torsional or longitudinal motion of the instrument tip. The cutting feature62may comprise a cutting face64A to aid in such removal. However, it should be appreciated that the ultrasonic tip26may 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 features62of the ultrasonic tip26may have a plurality of configurations. Referring toFIGS.10A-10E, various exemplary configurations of the cutting feature62of the ultrasonic tip26are illustrated. The cutting feature62may comprise a cutting face64, wherein the cutting face64comprises one or more teeth65. The teeth65of the cutting face64may be arranged wherein the teeth65are directed radially outward from the longitudinal axis46of the ultrasonic tip26. For certain configurations the plane of the cutting feature is substantially parallel yet offset to the central axis of the distal end50of the instrument, however the position of the cutting face64can be varied in a virtually limitless manner.

Referring toFIG.10B, a first configuration of the cutting feature62is illustrated. The first configuration of the cutting feature62comprises a cutting surface64B that includes a plurality of teeth65disposed radially about the distal end50of the shaft48. For example, the teeth65may configured to be directed outwardly from the longitudinal axis46of the ultrasonic tip26, and the teeth65arrange to encircle the entire circumference of the distal end of the shaft48. At least some of the teeth extend distally.

Alternatively,FIG.10Cillustrates a second configuration of the cutting feature62. The second configuration of the cutting feature62comprises a cutting surface64C comprising an arched or half cylinder-like shape that includes a plurality of teeth65directed outwardly from the longitudinal axis of the ultrasonic tip26.

FIG.10Dillustrates a third configuration of the cutting feature62. The third configuration of the cutting feature62comprises a cutting surface64D comprising an arched or half cylinder-like shape that includes a plurality of teeth65directed outwardly from the longitudinal axis of the ultrasonic tip26. The cutting surface64D is generally offset from the shaft48of the ultrasonic tip26and oriented to be perpendicular to the longitudinal axis46of the ultrasonic tip26.

FIG.10Eillustrates a fourth configuration of the cutting feature62. The fourth configuration of the cutting feature62comprises a cutting surface64E comprising an arched or half cylinder-like shape that includes a plurality of teeth65directed outwardly from the longitudinal axis of the ultrasonic tip26. The cutting surface64E is generally offset from the shaft of the ultrasonic tip26and oriented to be perpendicular to the longitudinal axis46of the ultrasonic tip26. Other suitable cutting features are also contemplated, including those described in U.S. Pat. No. 8,512,340; and U.S. Publication 2018/0103976; which are hereby incorporated by reference in their entirety.

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, while the example configurations describe the surgical instrument as an ultrasonic handpiece, it is further contemplated that the features and concepts described with regard to the ultrasonic handpiece may be applied to other medical or surgical instruments. This similarly applies to the ultrasonic tip, which 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. Many modifications and variations are possible in light of the above teachings and the invention may be practiced otherwise than as specifically described.