Ultrasonic surgical handpiece with torsional transducer

Abstract

To provide an ultrasonic surgical handpiece with a torsional transducer.SOLUTION: The surgical handpiece 12 includes a motor having a torsional transducer assembly along a central axis of the surgical handpiece 12. The motor is configured to operatively connect to the power source 24. The torsional transducer assembly includes a plurality of torsional transducers. Each torsional transducer has a support band surrounding the torsional transducer. The surgical handpiece 12 includes a surgical attachment having a first end 15 removably connected to the motor and a second end 13 defining a working surface for engaging biological tissue.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to ultrasonic surgical devices, and more particularly, to an ultrasonic surgical handpiece having a torsional transducer that generates standing waves that define an alternating pattern of nodes and anti-nodes along the handpiece, the locations of the anti-nodes corresponding to the locations of the working surface that engages biological tissue. [Background technology]

[0002] Ultrasonic surgical devices are used in surgical procedures for a variety of applications, including dissection, aspiration, coagulation, and cutting biological tissue. Typically, ultrasonic surgical devices operate as half-wave resonators by using piezoelectric transducers to generate high-frequency vibrations that vibrate various surgical instruments at their resonant frequency. Resonance can generally be defined as the time-harmonic exchange of distributed elastic strain energy with kinetic energy of distributed elastic motion of a structure. The vibrations can be longitudinal, radial, bending, torsional, or a combination of such forms of vibration. For purposes of physical analysis, such vibrations can be mathematically represented as standing waves, each composed of two waves of strain or motion superimposed on the structure, each traveling in the opposite direction from the other, resulting in the formation of points of no motion and maximum strain (nodes) and points of maximum motion and minimum or vanishing strain (antinodes).

[0003] Compared to conventional surgical instruments and techniques, ultrasonic surgical devices offer many advantages. For example, ultrasonic vibrations provide more precise cutting and better coagulation of tissue than electrosurgical instruments, thereby reducing bleeding and damage to surrounding tissue. Furthermore, ultrasonic vibrations cause less thermal damage, such as charring, and less desiccation than cryogenic or electrosurgical instruments.

[0004] However, the benefits of ultrasonic surgical devices are limited by the use of so-called longitudinal vibrations, in which the transducer generates axial vibrations along the axis of the device. Thus, the longitudinal vibrations of the transducer cause the surgical instrument to move back and forth in the axial direction, which still limits the precision of the surgical instrument during the surgical procedure and generates considerable heat energy that can damage surrounding tissue. Additionally, the longitudinal vibrations cause cavitation of the irrigation fluid typically used in the surgical procedure, obscuring the field of view during the surgical procedure.

[0005] In comparison, twisting motion of the surgical tip provides smoother, more precise control and causes less damage to surrounding tissue. In addition, less thermal energy is generated by the twisting motion, resulting in less thermal damage to surrounding tissue. The twisting motion also reduces cavitation of the irrigation fluid, resulting in improved visibility during the surgical procedure. Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, there is a need for an ultrasonic surgical handpiece that uses torsional transducers to provide more accurate and efficient surgery. [Means for solving the problem]

[0007] In one embodiment, a surgical handpiece includes a motor having a torsional transducer assembly along a central axis of the surgical handpiece. The motor is configured to operably connect to a power source. The surgical attachment has a first end removably connected to the motor and a second end defining a working surface for engaging biological tissue. The motor is configured to generate standing waves along the central axis in response to application of current and voltage from the power source. The standing waves define an alternating pattern of nodes and antinodes along the central axis. The location of one of the antinodes along the central axis corresponds to the location of the working surface.

[0008] In another embodiment, a surgical handpiece includes a plurality of torsional transducers along a central axis of the surgical handpiece. The plurality of torsional transducers is configured to be operably connected to a power source. The surgical attachment has a first end detachably connected to the plurality of torsional transducers and a second end defining a working surface for engaging biological tissue. The plurality of torsional transducers is configured to generate standing waves along the central axis in response to application of current and voltage from the power source. The standing waves define an alternating pattern of nodes and antinodes along the central axis. The location of one of the antinodes along the central axis corresponds to the location of the working surface.

[0009] In another embodiment, a method of operating a surgical handpiece includes providing a motor having a torsional transducer assembly along a central axis of the surgical handpiece, and a surgical attachment having a first end removably connected to the motor and a second end defining a working surface for engaging biological tissue, wherein power is supplied to the motor and a standing wave is formed defining an alternating pattern of nodes and antinodes along the central axis, the location of one of the antinodes along the central axis corresponding to the location of the working surface.

[0010] In one embodiment, a surgical handpiece is provided, including a motor having a torsional transducer assembly along a central axis of the surgical handpiece. The motor is configured to be operably connected to a power source. The torsional transducer assembly includes a plurality of torsional transducers. Each torsional transducer has a support band surrounding the torsional transducer. The surgical handpiece includes a surgical attachment having a first end removably connected to the motor and a second end defining a working surface for engaging biological tissue.

[0011] In some embodiments, the support band comprises a ring-like structure including an inner surface that engages the outer surface of the torsional transducer to support the torsional transducer.

[0012] In some embodiments, the support band is made from a metallic material, such as aluminum and / or an aluminum alloy.

[0013] In some embodiments, the support band has a width and the torsional transducer includes a width, wherein the width of the support band is approximately equal to the width of the torsional transducer.

[0014] In some embodiments, the support band has a stiffness greater than the stiffness of the torsional transducer.

[0015] In some embodiments, the motor is configured to generate a standing wave along the central axis in response to application of current and voltage from the power source, the standing wave defining an alternating pattern of nodes and anti-nodes along the central axis, and the location of one of the anti-nodes along the central axis corresponds to the location of the work surface.

[0016] In some embodiments, the surgical attachment has a joint at a location along the central axis that correlates with one of the nodes to increase the amplitude of the standing wave at the working surface.

[0017] In some embodiments, each torsional transducer includes an end face having a surface roughness configured to be in acoustic contact with an end face of another torsional transducer, or each torsional transducer includes a piezoelectric ring.

[0018] In some embodiments, each torsional transducer includes a piezoelectric ring.

[0019] In some embodiments, the torsional transducer is configured to vibrate the ultrasonic tip of the surgical attachment in a torsional motion about a central axis.

[0020] In some embodiments, the torsional transducer is configured to operate as a full wavelength resonator along the central axis of the handpiece.

[0021] In some embodiments, the torsional transducer assembly includes a first stack of torsional transducers and a second stack of torsional transducers facing each other about an interface.

[0022] In some embodiments, the surgical attachment includes an angled adapter.

[0023] In some embodiments, the surgical attachment includes an ultrasonic tip, the ultrasonic tip including a plurality of tines configured to correspond to a resonant frequency as a function of peak-to-peak amplitude, or the surgical attachment includes an angled adapter.

[0024] In some embodiments, the motor further includes a connector block aligned along a central axis of the surgical handpiece and an amplifier aligned along the central axis of the surgical handpiece.

[0025] In another embodiment, a surgical handpiece is provided, including a motor having a torsional transducer assembly along a central axis of the surgical handpiece. The motor is configured to be operably connected to a power source. The torsional transducer assembly includes a torsional transducer stack having a plurality of torsional transducers stacked end-to-end, bolts holding the torsional transducers within the torsional transducer stack, support bands surrounding the corresponding torsional transducers, and a set of electrodes electrically connected to the corresponding torsional transducers. The surgical handpiece includes a surgical attachment having a first end removably connected to the motor and a second end defining a working surface. The surgical attachment includes an ultrasonic tip at the working surface for engaging biological tissue.

[0026] In some embodiments, the support band comprises a ring-like structure including an inner surface that engages the outer surface of the torsional transducer to support the torsional transducer.

[0027] In some embodiments, the support band has a stiffness greater than the stiffness of the torsional transducer.

[0028] In some embodiments, the torsional transducer is configured to vibrate the ultrasonic tip of the surgical attachment in a torsional motion about a central axis.

[0029] In some embodiments, the motor is configured to generate a standing wave along the central axis in response to application of current and voltage from the power source, the standing wave defining an alternating pattern of nodes and anti-nodes along the central axis, and the location of one of the anti-nodes along the central axis corresponds to the location of the work surface.

[0030] In a further embodiment, a surgical handpiece is provided, including a plurality of torsional transducers along a central axis of the surgical handpiece. The plurality of torsional transducers are configured to be operably connected to a power source. The surgical handpiece includes a support band surrounding the corresponding torsional transducer for supporting the corresponding torsional transducer. The surgical handpiece includes a surgical attachment operably coupled to the plurality of torsional transducers. The surgical attachment has an ultrasonic tip at a working surface for engaging biological tissue. The plurality of torsional transducers are configured to generate standing waves along the central axis in response to application of current and voltage from the power source. The standing waves define an alternating pattern of nodes and antinodes along the central axis. The location of one of the antinodes along the central axis corresponds to the location of the working surface.

[0031] In some embodiments, the torsional transducer is configured to vibrate the ultrasonic tip of the surgical attachment in a torsional motion about a central axis.

[0032] In some embodiments, the support band comprises a ring-like structure including an inner surface that engages the outer surface of the torsional transducer to support the torsional transducer.

[0033] In some embodiments, the support band has a stiffness greater than the stiffness of the torsional transducer.

[0034] The subject matter of the present invention will be better understood upon reading the following description of non-limiting embodiments, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0035] [Figure 1]FIG. 1 is a perspective view of an ultrasonic surgical system, according to some embodiments. [Figure 2] 2 is a cross-sectional view of the ultrasonic surgical handpiece with the housing removed along section AA shown in FIG. 1 and a corresponding schematic diagram illustrating standing waves along the ultrasonic surgical handpiece, according to some embodiments. [Figure 3] FIG. 1 is a perspective view of an ultrasound tip, according to some embodiments. [Figure 4] FIG. 10 is an end view of an ultrasonic tip illustrating torsional motion in a working plane, according to some embodiments. [Figure 5] FIG. 1 is a partially exploded perspective view of an ultrasonic surgical handpiece with the housing removed and connections according to some embodiments. [Figure 6] 2 is a cross-sectional view of an ultrasonic surgical handpiece taken along section AA shown in FIG. 1 according to some embodiments. [Figure 7] FIG. 1 is an exploded perspective view of a motor and surgical attachment of an ultrasonic surgical handpiece, according to some embodiments. [Figure 8] FIG. 1 illustrates a side view of a motor, according to some embodiments. [Figure 9] 9 is a cross-sectional view of a motor taken along section BB shown in FIG. 8 according to some embodiments. [Figure 10] 9 is a cross-sectional view of a motor taken along section CC shown in FIG. 8 according to some embodiments. [Figure 11] FIG. 1 is a perspective view of an ultrasonic surgical system, according to some embodiments. [Figure 12a] 12 is a cross-sectional view of an ultrasonic surgical handpiece with the housing removed along section DD shown in FIG. 11 according to some embodiments. [Figure 12b] 10A-10C are corresponding schematic diagrams illustrating standing waves along an ultrasonic surgical handpiece, according to some embodiments. [Figure 13] FIG. 1 is a perspective view of an ultrasound tip, according to some embodiments. [Figure 14]FIG. 10 is an end view of an ultrasonic tip illustrating torsional motion in a working plane, according to some embodiments. [Figure 15] FIG. 1 is a partially exploded perspective view of an ultrasonic surgical handpiece and connection assembly with the housing removed, according to some embodiments. [Figure 16] 12 is a cross-sectional view of an ultrasonic surgical handpiece taken along section AA shown in FIG. 11 according to some embodiments. [Figure 17] FIG. 1 is an exploded perspective view of a motor and surgical attachment of an ultrasonic surgical handpiece, according to some embodiments. [Figure 18] FIG. 1 illustrates a side view of a motor, according to some embodiments. [Figure 19] FIG. 19 is a cross-sectional view of a motor taken along section EE shown in FIG. 18 according to some embodiments. [Figure 20] 9 is a cross-sectional view of a motor taken along section FF shown in FIG. 8 according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0036] Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

[0037] The following detailed description illustrates the present subject matter by way of example, and not by way of limitation. The description enables one skilled in the art to make and use the present subject matter and describes several embodiments of the present subject matter, as well as adaptations, variations, alternatives, and uses of the present subject matter. In addition, it is to be understood that the present subject matter is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present subject matter is capable of other embodiments and of being practiced or carried out in various ways. It is also to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting all embodiments of the present subject matter.

[0038] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may be intended to include the plural forms unless the context clearly dictates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and thus specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. The steps, processes, and operations described herein should not be construed as necessarily requiring performance in the particular order discussed or illustrated, unless specifically identified as a preferred order of performance. It should also be understood that additional or alternative steps may be employed.

[0039] The embodiments described herein include an ultrasonic surgical system having a control system, a surgical handpiece, a motor, and a surgical attachment for use in a surgical procedure to engage biological tissue. For example, the ultrasonic surgical system may include a surgical handpiece with a motor having a torsional transducer assembly. The torsional transducer assembly may have various configurations as described herein. For example, the transducer assembly may be configured to generate a standing wave along a central axis of the surgical handpiece in response to application of current and voltage from a power source or control system. The standing wave may define an alternating pattern of nodes and antinodes along the central axis, with the location of one of the antinodes corresponding to the location of a working surface of the surgical attachment that engages biological tissue, including both soft and hard tissue. The surgical attachment may have various configurations as described herein. Optionally, the ultrasonic surgical system may include an irrigation assembly and / or an aspiration assembly for irrigating and / or aspirating biological tissue.

[0040] FIG. 1 is a perspective view of an ultrasonic surgical system 10 constructed in accordance with an embodiment including a surgical handpiece 12 extending between opposing first and second ends 15 and 13. The second end 13 is operably connected to a control system 14 using a connection assembly 16. In an exemplary embodiment, the control system 14 is configured to provide power, irrigation fluid, and aspiration or suction at a working surface 18 of the first end 15 of the handpiece 12 during a surgical procedure. The working surface 18 of the handpiece 12 may engage biological tissue 20 at a surgical site 22 to perform various surgical procedures, such as coagulation cutting, irrigation, and aspiration. In alternative embodiments, the handpiece 12 may be configured to engage soft biological tissue, such as muscle tissue, connective tissue, nerve tissue, or epithelial tissue, or hard biological tissue, such as bone, enamel, dentin, or cement.

[0041] 2 is a cross-sectional view of ultrasonic surgical handpiece 12 with the housing removed along section AA shown in FIG. 1 and a corresponding schematic diagram illustrating a standing wave 100 along ultrasonic surgical handpiece 12 according to one embodiment. In response to application of current and voltage from control system 14, handpiece 12 generates standing wave 100 along central axis A having an alternating pattern of nodes 102 and anti-nodes 104 located at various positions along central axis A. The X-axis of the schematic diagram indicates the locations of nodes 102 and anti-nodes along central axis A of handpiece 12. The Y-axis indicates the amplitude of standing wave 100 along central axis A of handpiece 12.

[0042] For example, anti-nodes 104 are located at the first end 284 of the connector block 202, the interface 150 between the first stack 212 and the second stack 214 of the transducer assembly 210, the interface 152 between the amplifier 206 and the surgical attachment 300, the interface 154 between the angled adapter 302 and the ultrasonic tip 304, and the working surface 18. For example, the distances between anti-nodes 14 along the handpiece 12 (from the second end to the first end) are approximately 0.903 inches, approximately 0.5922 inches, approximately 0.658 inches, approximately 1.087 inches, approximately 1.057 inches, approximately 1.66 inches, approximately 1.626 inches, and approximately 1.365 inches. For example, the amplitude of the standing wave 100 gradually increases along the central axis A of the handpiece 12 approaching the first end 15 of the handpiece 12, with the maximum amplitude at the working surface 18.

[0043] In some embodiments, the standing wave 100 can be described as a wave that oscillates in time but whose peak amplitude profile does not move in space. The standing wave 100 can represent a distribution of motion along the length of the surgical handpiece 12, whose amplitude varies harmonically in time but remains stationary in space. The peak amplitude of the wave's oscillation at any point in space is constant in time, and oscillations at different points throughout the wave are synchronized with each other. A standing wave pattern defines an alternating pattern of node locations, such as nodes and antinodes. Once a standing wave is established, the nodes and antinodes remain at the same locations along the medium. A node of a standing wave is where the amplitude of the standing wave is minimum and may include zero. At a node, there is minimal or no displacement during each oscillation cycle. The standing wave 100 can be formed by the interference of two traveling waves. Thus, nodes are generated where destructive interference occurs. An antinode of a standing wave is where the amplitude of the standing wave is maximum. Antinodes have the maximum displacement during each oscillation cycle. Antinodes oscillate back and forth between positive and negative displacements. Antinodes are created where constructive interference occurs.

[0044] Figure 3 is a perspective view of an ultrasonic tip 304 according to one embodiment. Figure 4 is an end view of the ultrasonic tip 304 illustrating torsional motion at the working surface 18 according to one embodiment. A standing wave 100 generated along the handpiece 12 results in torsional motion about a central axis A at the working surface 18 of the surgical attachment 300. For example, the amplitude AA of the ultrasonic tip 304 at the working surface 18 may be up to about 18 mils peak-to-peak (450 microns) at an operating resonant frequency of about 24,500-25,500 Hz. However, alternative embodiments may produce other amplitudes at the working surface 18 and / or at other operating resonant frequencies.

[0045] 1 , the control system 14 includes a power supply 24 that provides electrical current and power to the handpiece 12 via the connection assembly 16. For example, the handpiece 12 may have an operating frequency in the range of 24,500-25,500 Hz and be driven by the control system 14 at a power in the range of 85-110 watts. In alternative embodiments, the handpiece 12 may have an operating frequency less than 24,500 Hz or greater than 25,500 Hz and be driven at a power less than 85 watts or greater than 110 watts.

[0046] The exemplary embodiment of the control system 14 also includes an irrigation fluid source 26 configured to provide irrigation fluid to the handpiece 12 via the connection assembly 16. In one embodiment, the handpiece 12 may be configured to transmit irrigation fluid through one or more irrigation channels of the handpiece 12 to the work surface 18 and the surgical site 22 for use as a coolant and irrigation. For example, the irrigation fluid source 26 may include an irrigation pump (not shown), such as a peristaltic pump, configured to pump water from a water source to the handpiece 12 via the connection assembly 16.

[0047] Additionally, the exemplary embodiment of the control system 14 includes a suction collector 28 for providing suction to the handpiece 12 via the connection assembly 16. In one embodiment, the handpiece 12 may be configured to provide suction to the work surface 18 and the surgical site 22 through a suction channel of the handpiece 12 for use as suction. For example, the suction collector 28 may include a vacuum pump (not shown) configured to generate a vacuum at the handpiece via the connection assembly 16 for transferring aspirated biological tissue from the work surface 18 and the surgical site 22 to a biological waste canister (not shown).

[0048] In the illustrated embodiment, the connection assembly 16 includes an electrical connection 30 that transfers power from the power source 24 of the control system 14 to the handpiece 12. For example, the electrical connection 30 includes an electrical cable 32 having a first end 34 coupled to the handpiece 12 and an electrical connector 36 attached to a second end 38 of the cable 32. Optionally, a strain relief 40 is attached to the cable end 42 of the electrical connector 36. As shown, the electrical connector 36 is a high-voltage modular connector, such as a connector manufactured by LEMO, that removably connects with the control system 14. However, in alternative embodiments, the connector may be any suitable connector that can operably connect with the control system 14.

[0049] The connection assembly 16 also includes an irrigation connection 44 that routes irrigation fluid from the irrigation fluid source 26 of the control system 14 to the handpiece 12. For example, the irrigation connection includes a tube 46 having a second end 48 connected to the control system 14 and a first end 50 coupled to the handpiece 12, such as by an irrigation barb 52 (FIG. 5).

[0050] The connection assembly 16 also includes a suction connection 74 that routes aspirated material from the handpiece 12 to the aspirator collector 28 of the control system 14. For example, the aspirator connection 74 includes a tube 76 having a second end 78 connected to the control system 14 and a first end 80 coupled to the handpiece 12, such as by a suction barb 82 (FIG. 5).

[0051] In one or more embodiments, the irrigation barb 52 and / or the suction barb 82 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof. For example, irrigation barb 52 and / or suction barb 82 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the irrigation barb 52 and / or the suction barb 82 may be fabricated from an attenuating material, a material having a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low clearance.

[0052] Figure 5 is a partially exploded perspective view of ultrasonic surgical handpiece 12 with housing 110 removed and a connection assembly according to an embodiment including motor 200 and surgical attachment 300. Figure 6 is a cross-sectional view of ultrasonic surgical handpiece 12 taken along section AA shown in Figure 1. In the exemplary embodiment, housing 110 includes inner sleeve 112, outer sleeve 114, collar 116, nosecone 118, and irrigation sleeve 120 that are removably assembled to receive motor 200 and surgical attachment 300 and define irrigation channel 122 (Figure 6) that communicates irrigation fluid from irrigation connection 44 to work surface 18. For example, substantially cylindrical inner sleeve 112 includes bore 124 configured to receive motor 200. The generally cylindrical outer sleeve 114 includes a bore 126 configured to receive the inner sleeve 112 and the motor 200 and defines a portion of the generally annular irrigation channel 122 between the inner sleeve 112 and the outer sleeve 114. The collar 116 removably couples, such as by a threaded connection, to a second end 128 of the outer sleeve 114. The nosecone 118 includes a second end 130 configured to removably couple, such as by a threaded connection, to a first end 132 of the outer sleeve 126 and define a portion of the irrigation channel 122. The irrigation sleeve 120 includes a second end 134 configured to removably couple, such as by a threaded connection, to a first end 136 of the nosecone 118 and define a portion of the irrigation channel 122. The second end 137 of the irrigation sleeve 120 defines an outlet 138 configured to direct irrigation fluid from the irrigation channel 122 to the work surface 18 and the surgical site 22. In one or more embodiments, each component of the housing 110 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof.

[0053] FIG. 7 is an exploded perspective view of the motor 200 and surgical attachment 300 of the ultrasonic surgical handpiece 12, according to one embodiment. In the exemplary embodiment, the surgical attachment 300 includes an angled adapter 302 and an ultrasonic tip 304 aligned along the central axis A of the handpiece 12. The angled adapter 302 includes a body 306 having a second end 308 removably connected to the motor 200, such as with a threaded hole 310, and a first end 312 removably connected to the ultrasonic tip 304, such as with a threaded hole 314. The body 306 includes a second portion 316 and a first portion 318 offset from each other at a junction 319 at an angle, for example, between approximately 10° and 45°, although any angle can be used. The angled adapter 302 may include an amplifier interface 320 at the second end 308 and an angled tip interface 324 at the first end 312. In one or more embodiments, the angled adapter 302 may include an angled adapter bore 330 and a tip bore 332 (FIG. 6). As shown in FIG. 2, the junction 319 is positioned to correlate with a node of the standing wave 100. The correlation of the junction 319 with the node 102 increases the amplitude of the standing wave 100 after the junction 319 as the junction 319 approaches the work surface 18.

[0054] In the exemplary embodiment, the ultrasonic tip 304 includes a body 334 having a second end 336 removably connected to the first end 312 of the angled adapter 302, such as by a threaded portion, and a first end 338 having a working surface 18 configured to engage biological tissue. The body 334 may include multiple portions having discretely different dimensions to correspond to the nodes 102 and anti-nodes 104 of the standing wave. For example, the body 306 may include a base portion 340 at the second end 336, a tip portion 342 at the first end 338, and a sloped intermediate portion 344 disposed between the base portion 340 and the tip portion 342. A bore 346 extends through the length of the body 334 along the central axis A. The ultrasonic tip 304 is configured such that the position of the working surface 18 corresponds to one of the anti-nodes 104 of the standing wave 100 when the handpiece 12 is assembled.

[0055] In an exemplary embodiment, the ultrasonic tip may include multiple tines configured to correspond to a resonant frequency as a function of peak-to-peak amplitude. During operation, the tines overlap each other peak-to-peak. The distance between the tines corresponds to a frequency that produces 10-15 peak-to-peak amplitudes.

[0056] In alternative embodiments of the surgical attachment 300, the angled adapter 302 and ultrasonic tip 304 may be configured with dimensions that correspond to the location of the working surface 18 with the anti-node 104 of the standing wave 100. For example, the ultrasonic tip 304 may have an overall length between the second end 316 and the first end 318 in a range of about 2.9 inches to about 3.1 inches. The base portion 340 may have a diameter in a range of about 0.2 inches to about 0.3 inches. In alternative embodiments of the surgical attachment 300, the ultrasonic tip 304 may be configured to accomplish various surgical procedures. For example, the ultrasonic tip 304, particularly the distal portion 342 at the working surface 18, may be configured to engage soft biological tissue, such as muscle tissue, connective tissue, nerve tissue, or epithelial tissue, or hard biological tissue, such as bone, enamel, dentin, or cement.

[0057] In one or more embodiments, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof. For example, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from an attenuating material, a material with a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low clearance.

[0058] Figure 8 is a side view of motor 200. Figure 9 is a cross-sectional view of motor 200 taken along section BB shown in Figure 8. Figure 10 is a cross-sectional view of motor 200 taken along section CC shown in Figure 8. In the exemplary embodiment, motor 200 includes a connector block 202 at a second end 204, an amplifier 206 at a first end 208, and a transducer assembly 210 disposed between connector block 202 and amplifier 206. Connector block 202, transducer assembly 210, and amplifier 206 are aligned along a central axis A of handpiece 12 and configured to operably connect to power source 24 via connection assembly 16 (Figure 1).

[0059] The transducer assembly 210 includes a first stack 212 and a second stack 214 aligned along a central axis A opposite each other about an interface 150 (FIG. 7). In an exemplary embodiment, the interface 150 of the first stack 212 and the second stack 214 correlates to the position of the antinode 104 (FIG. 2). The respective positions of the first and second stacks 212, 214 relative to the node 102 and the antinode 104 position the first and second stacks 212, 214, respectively, within zones of minimum amplitude, reducing mechanical stress and power loss on the transducer assembly 210.

[0060] Each of the first and second stacks 212, 214 is configured to operate or resonate as a full-wavelength resonator. Each of the first and second stacks 212, 214 includes a shaft or bolt 216 configured to couple with a plurality of torsional transducers 218, a set of electrodes 220, and an inert ring 222 ( FIG. 7 ). For example, the shaft 216 may include a raised collar 224 at a first end 226 that abuts the inert ring 222 with a pair of torsional transducers 218 adjacent to the inert ring 222. A second end 228 of the first stack 212 is connected to the connector block 202, and a second end 230 of the second stack 214 is connected to the amplifier 206. The set of three electrodes 220 is disposed between the components and operably connected to the control system 14 via electrical connections 30 of the connection assembly 16 ( FIG. 1 ). An insulator sleeve 232 is disposed between the shaft 216, the torsional transducer 218, the electrode 220, and the inert ring 222 to provide electrical insulation between the components. For example, the insulator 232 may be a generally cylindrical sleeve constructed of any suitable electrically insulating material, such as a thermoplastic polymer material. Once assembled, the transducer assembly is placed under a predetermined amount of prestress to provide proper connection between the components. For example, the transducer assembly 210 is placed under a prestress in the range of approximately 1500-2500 psi. In alternative embodiments, the transducer assembly 210 may include any number of stacks of torsional transducers, including a single stack.

[0061] In the illustrated embodiment, each torsional transducer 218 is a piezoelectric ring configured to convert electrical energy into ultrasonic vibrations. Each transducer 218 includes a second end face 234, a first end face 236, a generally annular outer surface 238, and a bore 240. The second and first end faces 234, 236 may each be generally smooth to increase acoustic contact between the transducers 218 when assembled. For example, the second and first end faces 234, 236 may each be polished to a surface roughness ranging from approximately 2Ra to 6Ra without any coating. The second end face 234 and / or the first end face 236 may have a surface finish layer that is sufficiently smooth to ensure good contact between the torsional transducers 218 in the stack. The surface finish layer may improve transmission between the torsional transducers 218. In an alternative embodiment, each ring may include a coating (not shown) of a predetermined thickness on one or more of its surfaces. The coating may be made from a conductive material such as aluminum, aluminum alloy, silver, silver alloy, copper, copper alloy, gold, gold alloy, platinum, platinum alloy, tin, tin alloy, palladium, palladium alloy, nickel, nickel alloy, beryllium, beryllium alloy, tungsten, tungsten alloy, steel, chromium, chromium alloy, titanium, titanium alloy, etc.

[0062] The dimensions of the transducer 218 are predetermined to achieve the appropriate piezoelectric effect. For example, the transducer 218 may have a thickness of approximately 0.145 to 0.215 inches. However, alternative embodiments may have a thickness less than 0.145 inches or greater than 0.215 inches. For example, the transducer 218 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 240 of the transducer 218 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches.

[0063] In exemplary embodiments, one or more of the torsional transducers 218 may be fabricated from a piezoelectric ceramic material, such as a perovskite material, a lead zirconate titanate ("PZT") material, a piezo-electric material, a PXE 5 grade material, a PXE 52 grade material, a PXE 59 grade material, a PXE 21 grade material, a PXE 41 grade material, a PXE 42 grade material, a PXE 43 grade material, or a PXE 71 grade material. Alternatively, each transducer may be fabricated from a material having a crystal structure without a center of symmetry, such as a perovskite crystal structure. In one or more embodiments, each torsional transducer 218 may be fabricated from a material having a tetragonal lattice element cell below the Curie temperature of the material, e.g., a cubic lattice element cell above the Curie temperature of the material.

[0064] In the exemplary embodiment, the inert ring 222 includes a second end surface 242, a first end surface 244, a generally annular outer surface 246, and a bore 248. The dimensions and materials of the transducer 218 are predetermined to achieve the appropriate configuration of the standing wave 100 along the central axis A and the corresponding locations of the nodes 102 and anti-nodes 104. For example, the inert ring 222 may have a thickness of approximately 0.265 to 0.385 inches. However, alternative embodiments may have thicknesses less than 0.265 inches or greater than 0.385 inches. For example, the inert ring 222 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 248 of the inert ring 222 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches.

[0065] In one or more embodiments, the inert ring 222 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the inert ring 222 may be made from titanium, titanium alloys, aluminum, aluminum alloys, copper, copper alloys, iron, iron alloys, nickel, nickel alloys, silver, silver alloys, cobalt, cobalt alloys, tin, tin alloys, gold, gold alloys, tungsten, tungsten alloys, beryllium, beryllium alloys, platinum, platinum alloys, chromium, chromium alloys, lead, lead alloys, palladium, palladium alloys, zinc, zinc alloys, rhodium, rhodium alloys, niobium, niobium alloys, vanadium, vanadium alloys, manganese, manganese alloys, indium and indium alloys, tantalum, tantalum alloys, molybdenum, molybdenum alloys, cadmium, cadmium alloys, thallium, thallium alloys, ruthenium, ruthenium alloys, iridium, iridium alloys, gallium, gallium alloys, osmium, osmium alloys, rhenium, rhenium alloys, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the inert ring 222 may be fabricated from a damping material, a material with a Q factor greater than 0.5, a metal alloy in an annealed state, a titanium alloy in an annealed state, or from Ti-6A1-4V ultra-low clearance in an annealed state.

[0066] In the exemplary embodiment, each electrode 220 is generally ring-shaped and includes a second end surface 250, a first end surface 252, a generally annular outer surface 254, and a bore 256. One or more of the electrodes may include leads 258 that operably connect to the control system 14 via electrical connections 30 of the connection assembly 16 (FIG. 1). The dimensions of the transducer 218 are predetermined to achieve proper connection between the components. For example, the electrodes 220 may have a thickness of approximately 0.700 to 0.900 inches. However, alternative embodiments may have a thickness less than 0.700 inches or greater than 0.900 inches. For example, the electrodes 220 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 256 of the electrode 220 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches. One or more of the electrodes 220 may be fabricated from aluminum, an aluminum alloy, silver, a silver alloy, copper, a copper alloy, gold, a gold alloy, platinum, a platinum alloy, tin, a tin alloy, palladium, a palladium alloy, nickel, a nickel alloy, beryllium, a beryllium alloy, tungsten, a tungsten alloy, steel, chromium, a chromium alloy, titanium, a titanium alloy, or the like.

[0067] In the illustrative embodiment, connector block 202 is a generally cylindrical component having a second end 260 configured to removably connect with connection assembly 16 and a first end 262 configured to mate with transducer assembly 210. An outer surface 264 of connector block 202 is configured to receive an O-ring that forms a hermetic seal with housing 110 ( FIG. 5 ). A suction bore 266 extends through connector block 202 having an inlet 268 at second end 260 for mating with suction barb 82 and an outlet 270 at first end 262 for mating with bore 290 of transducer assembly 210. An irrigation bore 272 extends through connector block 202 having an inlet 274 at second end 260 for mating with irrigation barb 52 and an outlet 276 at first end 262 for mating with irrigation channel 122. The dimensions of the transducer 218 are predetermined to achieve the proper configuration of the standing wave 100 and corresponding positions of the nodes 102 and anti-nodes 104 .

[0068] In one or more embodiments, the connector block 202 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the connector block 202 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the connector block 202 may be fabricated from a damping material, a material with a Q factor greater than 0.5, a metal alloy in an annealed state, a titanium alloy in an annealed state, or from Ti-6A1-4V ultra-low interstitial quality in an annealed state.

[0069] In the exemplary embodiment, amplifier 206 is a generally cylindrical component having a first end 284 configured to removably connect with surgical attachment 300 and a second end 286 configured to mate with transducer assembly 210 (FIG. 5). The dimensions of amplifier 206 are predetermined to achieve the appropriate configuration of standing wave 100 and corresponding locations of nodes 102 and anti-nodes 104.

[0070] In one or more embodiments, the amplifier 206 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the amplifier 206 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, amplifier 206 may be fabricated from a damping material, a material with a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low interstitial quality.

[0071] 11-20 illustrate an embodiment of an ultrasonic surgical system 10 including an exemplary embodiment of a surgical handpiece 12. The ultrasonic surgical system 10 and surgical handpiece 12 illustrated in FIGS. 11-20 are similar to the ultrasonic surgical system 10 and surgical handpiece 12 illustrated in FIGS. 1-10, and like components are identified with like reference numerals.

[0072] 11 is a perspective view of an ultrasonic surgical system 10 constructed in accordance with an embodiment including a surgical handpiece 12. The surgical handpiece 12 extends between opposing first and second ends 15 and 13. Depending on the orientation from a user's or patient's perspective, the first end 15 may be the proximal end and the second end 13 may be the distal end, or vice versa. The second end 13 is operably connected to a control system 14 using a connection assembly 16.

[0073] In the exemplary embodiment, control system 14 is configured to provide power, irrigation fluid, and aspiration or suction at working surface 18 of first end 15 of handpiece 12 during a surgical procedure. Working surface 18 of handpiece 12 may engage biological tissue 20 at a surgical site 22 to perform various surgical procedures, such as coagulation cutting, irrigation, and aspiration. In alternative embodiments, handpiece 12 may be configured to engage soft biological tissue, such as muscle tissue, connective tissue, nerve tissue, epithelial tissue, or hard biological tissue, such as bone, enamel, dentin, cement, etc.

[0074] FIGURE 12a is a cross-sectional view of ultrasonic surgical handpiece 12 with the outer housing removed, taken along cross section DD shown in FIGURE 11, and FIGURE 12b is a corresponding schematic diagram showing a standing wave 100 along ultrasonic surgical handpiece 12 according to one embodiment. In response to application of current and voltage from control system 14, handpiece 12 generates standing wave 100 along central axis A having an alternating pattern of nodes 102 and anti-nodes 104 located at various positions along central axis A. The X-axis of the schematic diagram indicates the location of nodes 102 and anti-nodes along central axis A of handpiece 12. The Y-axis indicates the amplitude of standing wave 100 along central axis A of handpiece 12.

[0075] For example, anti-nodes 104 are located at the first end 284 of the connector block 202, the interface 150 between the first stack 212 and the second stack 214 of the transducer assembly 210, the interface 152 between the amplifier 206 and the surgical attachment 300, the interface 154 between the angled adapter 302 and the ultrasonic tip 304, and the working surface 18. For example, the distances between anti-nodes 14 along the handpiece 12 (from the second end 13 to the first end 15) are approximately 0.903 inches, approximately 0.5922 inches, approximately 0.658 inches, approximately 1.087 inches, approximately 1.057 inches, approximately 1.66 inches, approximately 1.626 inches, and approximately 1.365 inches. For example, the amplitude of the standing wave 100 gradually increases along the central axis A of the handpiece 12 approaching the first end 15 of the handpiece 12, with the maximum amplitude at the working surface 18.

[0076] In some embodiments, the standing wave 100 can be described as a wave that oscillates in time but whose peak amplitude profile does not move in space. The standing wave 100 can represent a distribution of motion along the length of the surgical handpiece 12, whose amplitude varies harmonically in time but remains stationary in space. The peak amplitude of the wave's oscillation at any point in space is constant in time, and oscillations at different points across the wave are synchronized with each other. The standing wave pattern defines an alternating pattern of node locations, such as nodes 102 and antinodes 104. Once a standing wave is established, the nodes 102 and antinodes 104 remain located at the same positions along the medium. Standing wave nodes are locations where the standing wave's amplitude is minimum and may include zero. At nodes 102, there is minimal or no displacement during each oscillation cycle. The standing wave 100 can be formed by the interference of two traveling waves. Thus, nodes 102 are created where destructive interference occurs. The antinode of a standing wave is the location where the amplitude of the standing wave is greatest. At the antinode 104, there is maximum displacement during each oscillation cycle. The antinode 104 oscillates back and forth between positive and negative displacements. The antinode 104 is created at the location where constructive interference occurs.

[0077] Figure 13 is a perspective view of an ultrasonic tip 304 according to one embodiment. Figure 14 is an end view of the ultrasonic tip 304 illustrating torsional motion at the working surface 18 according to one embodiment. The standing wave 100 generated along the handpiece 12 results in torsional motion about the central axis A at the working surface 18 of the surgical attachment 300. For example, the amplitude of the ultrasonic tip 304 at the working surface 18 may be up to about 18 mils peak-to-peak (450 microns) at an operating resonant frequency of about 24,500-25,500 Hz. However, alternative embodiments may produce other amplitudes at the working surface 18 and / or at other operating resonant frequencies.

[0078] 11 , the control system 14 includes a power supply 24 that provides electrical current and power to the handpiece 12 via the connection assembly 16. For example, the handpiece 12 may have an operating frequency in the range of 24,500-25,500 Hz and be driven by the control system 14 at a power in the range of 85-110 watts. In alternative embodiments, the handpiece 12 may have an operating frequency less than 24,500 Hz or greater than 25,500 Hz and be driven at a power less than 85 watts or greater than 110 watts.

[0079] The exemplary embodiment of the control system 14 also includes an irrigation fluid source 26 configured to provide irrigation fluid to the handpiece 12 via the connection assembly 16. In one embodiment, the handpiece 12 may be configured to transmit irrigation fluid through one or more irrigation channels of the handpiece 12 to the work surface 18 and the surgical site 22 for use as a coolant and irrigation. For example, the irrigation fluid source 26 may include an irrigation pump (not shown), such as a peristaltic pump, configured to pump water from a water source to the handpiece 12 via the connection assembly 16.

[0080] Additionally, the exemplary embodiment of the control system 14 includes a suction collector 28 for providing suction to the handpiece 12 via the connection assembly 16. In one embodiment, the handpiece 12 may be configured to provide suction to the work surface 18 and the surgical site 22 through a suction channel of the handpiece 12 for use as suction. For example, the suction collector 28 may include a vacuum pump (not shown) configured to generate a vacuum at the handpiece via the connection assembly 16 for transferring aspirated biological tissue from the work surface 18 and the surgical site 22 to a biological waste canister (not shown).

[0081] In the illustrated embodiment, the connection assembly 16 includes an electrical connection 30 that transfers power from the power source 24 of the control system 14 to the handpiece 12. For example, the electrical connection 30 includes an electrical cable 32 having a first end 34 coupled to the handpiece 12 and an electrical connector 36 attached to a second end 38 of the cable 32. Optionally, a strain relief 40 is attached to the cable end 42 of the electrical connector 36. As shown, the electrical connector 36 is a high-voltage modular connector, such as a connector manufactured by LEMO, that removably connects with the control system 14. However, in alternative embodiments, the connector may be any suitable connector that can operably connect with the control system 14.

[0082] The connection assembly 16 also includes an irrigation connection 44 that routes irrigation fluid from the irrigation fluid source 26 of the control system 14 to the handpiece 12. For example, the irrigation connection includes a tube 46 having a second end 48 connected to the control system 14 and a first end 50 coupled to the handpiece 12, such as by an irrigation barb 52 (FIG. 15).

[0083] The connection assembly 16 also includes a suction connection 74 that routes aspirated material from the handpiece 12 to the aspirator collector 28 of the control system 14. For example, the aspirator connection 74 includes a tube 76 having a second end 78 connected to the control system 14 and a first end 80 coupled to the handpiece 12, such as by a suction barb 82 (FIG. 15).

[0084] In one or more embodiments, the irrigation barb 52 and / or the suction barb 82 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof. For example, irrigation barb 52 and / or suction barb 82 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the irrigation barb 52 and / or the suction barb 82 may be fabricated from an attenuating material, a material having a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low clearance.

[0085] Figure 15 is a partially exploded perspective view of ultrasonic surgical handpiece 12 with housing 110 removed and a connection assembly according to an embodiment including motor 200 and surgical attachment 300. Figure 16 is a cross-sectional view of ultrasonic surgical handpiece 12 taken along cross section DD shown in Figure 11. In the exemplary embodiment, housing 110 includes inner and outer sleeves 112 and 114, collar 116, nosecone 118, and irrigation sleeve 120 that are removably assembled to receive motor 200 and surgical attachment 300 and define irrigation channel 122 (Figure 16) that communicates irrigation fluid from irrigation connection 44 to work surface 18. For example, substantially cylindrical inner sleeve 112 includes bore 124 configured to receive motor 200. The generally cylindrical outer sleeve 114 includes a bore 126 configured to receive the inner sleeve 112 and the motor 200 and defines a portion of the generally annular irrigation channel 122 between the inner sleeve 112 and the outer sleeve 114. The collar 116 removably couples, such as by a threaded connection, to a second end 128 of the outer sleeve 114. The nosecone 118 includes a second end 130 configured to removably couple, such as by a threaded connection, to a first end 132 of the outer sleeve 114 and define a portion of the irrigation channel 122. The irrigation sleeve 120 includes a second end 134 configured to removably couple, such as by a threaded connection, to a first end 136 of the nosecone 118 and define a portion of the irrigation channel 122. The first end 137 of the irrigation sleeve 120 defines an outlet 138 configured to direct irrigation fluid from the irrigation channel 122 to the work surface 18 and the surgical site 22. In one or more embodiments, each component of the housing 110 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof.

[0086] FIG. 17 is an exploded perspective view of the motor 200 and surgical attachment 300 of the ultrasonic surgical handpiece 12 according to one embodiment. In the exemplary embodiment, the surgical attachment 300 includes an angled adapter 302 and an ultrasonic tip 304 aligned along the central axis A of the handpiece 12. The angled adapter 302 includes a body 306 having a second end 308 removably connected to the motor 200, such as with a threaded hole 310, and a first end 312 removably connected to the ultrasonic tip 304, such as with a threaded hole 314. The body 306 includes a second portion 316 and a first portion 318 offset from each other at a junction 319 at an angle, for example, between about 10° and 45°, although any angle can be used. The angled adapter 302 may include an amplifier interface 320 at the second end 308 and an angled tip interface 324 at the first end 312. In one or more embodiments, the angled adapter 302 may include an angled adapter bore 330 and a tip bore 332 ( FIG. 16 ). As shown in FIG. 12 , the junction 319 is positioned to correlate with a node of the standing wave 100. The correlation of the junction 319 with the node 102 increases the amplitude of the standing wave 100 after the junction 319 as the junction 319 approaches the work surface 18. In alternative embodiments, the surgical attachment 300 may be connected to an amplifier without the use of the angled adapter 302. In other alternative embodiments, the adapter may be straight rather than angled so that the ultrasonic tool extends along a straight path rather than along an angled path.

[0087] In the exemplary embodiment, the ultrasonic tip 304 includes a body 334 including a second end 336 removably connected to the first end 312 of the angled adapter 302, such as by a threaded portion, and a first end 338 having a working surface 18 configured to engage biological tissue. The body 334 may include multiple portions having discretely different dimensions to correspond to the nodes 102 and anti-nodes 104 of the standing wave. For example, the body 334 may include a base portion 340 at the second end 336, a tip portion 342 at the first end 338, and a sloped intermediate portion 344 disposed between the base portion 340 and the tip portion 342. A bore 346 extends through the length of the body 334 along the central axis A. The ultrasonic tip 304 is configured such that the position of the working surface 18 corresponds to one of the anti-nodes 104 of the standing wave 100 when the handpiece 12 is assembled.

[0088] In an exemplary embodiment, the ultrasonic tip 304 may include one or more teeth configured to correspond to a resonant frequency as a function of peak-to-peak amplitude. During operation, the movement of the teeth may overlap one another peak-to-peak. However, the teeth may follow non-overlapping paths in alternative embodiments. The distance between the teeth corresponds to a frequency that produces 10-15 peak-to-peak amplitudes. The ultrasonic tip 304 may include other abrasive surfaces other than teeth to perform surgical functions, such as abrasives, linear cutting elements, or other shaping features.

[0089] In alternative embodiments of the surgical attachment 300, the angled adapter 302 and ultrasonic tip 304 may be configured with dimensions that correspond to the location of the working surface 18 with the anti-node 104 of the standing wave 100. For example, the ultrasonic tip 304 may have an overall length between the second end 316 and the first end 318 in a range of about 2.9 inches to about 3.1 inches. The base portion 340 may have a diameter in a range of about 0.2 inches to about 0.3 inches. In alternative embodiments of the surgical attachment 300, the ultrasonic tip 304 may be configured to accomplish various surgical procedures. For example, the ultrasonic tip 304, particularly the distal portion 342 at the working surface 18, may be configured to engage soft biological tissue, such as muscle tissue, connective tissue, nerve tissue, or epithelial tissue, or hard biological tissue, such as bone, enamel, dentin, or cement.

[0090] In one or more embodiments, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or any combination thereof. For example, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the angled adapter 302 and / or the ultrasonic tip 304 may be fabricated from an attenuating material, a material with a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low interstitial material.

[0091] Figure 18 is a side view of motor 200. Figure 19 is a cross-sectional view of motor 200 taken along section EE shown in Figure 18. Figure 20 is a cross-sectional view of motor 200 taken along section FF shown in Figure 18. In the exemplary embodiment, motor 200 includes a connector block 202 at a second end 204, an amplifier 206 at a first end 208, and a transducer assembly 210 disposed between connector block 202 and amplifier 206. Connector block 202, transducer assembly 210, and amplifier 206 are aligned along a central axis A of handpiece 12 and configured to operably connect to power source 24 via connection assembly 16 (Figure 11).

[0092] The transducer assembly 210 includes a first stack 212 and a second stack 214 aligned along a central axis A opposite each other about an interface 150 ( FIG. 17 ). In an exemplary embodiment, the interface 150 of the first stack 212 and the second stack 214 correlates with the position of the antinode 104 ( FIG. 12 ). The respective positions of the first and second stacks 212, 214 relative to the node 102 and the antinode 104 position the first and second stacks 212, 214, respectively, within zones of minimum amplitude, reducing mechanical stress and power loss on the transducer assembly 210. The transducer assembly 210 may include more or fewer stacks in alternative embodiments, such as a single stack.

[0093] The first and second stacks 212, 214 are each configured to operate or resonate as a full-wavelength resonator. Each of the first and second stacks 212, 214 includes a shaft or bolt 216 configured to couple to a plurality of torsional transducers 218, a support band 292 configured to surround the torsional transducers 218, a set of electrodes 220, and an inert ring 222 ( FIG. 17 ). For example, the shaft 216 may include a raised collar 224 at a first end 226 that abuts the inert ring 222 with a pair of torsional transducers 218 adjacent to the inert ring 222. The second end 228 of the first stack 212 is connected to the connector block 202, and the second end 230 of the second stack 214 is connected to the amplifier 206. The set of three electrodes 220 is disposed between the components and operably connected to the control system 14 via electrical connections 30 of the connection assembly 16 ( FIG. 11 ). An insulator sleeve 232 is disposed between the shaft 216, the torsional transducer 218, the electrode 220, and the inert ring 222 to provide electrical insulation between the components. For example, the insulator 232 may be a generally cylindrical sleeve constructed of any suitable electrically insulating material, such as a thermoplastic polymer material. Once assembled, the transducer assembly is placed under a predetermined amount of prestress to provide proper connection between the components. For example, the transducer assembly 210 is placed under a prestress in the range of approximately 1500-2500 psi. In alternative embodiments, the transducer assembly 210 may include any number of stacks of torsional transducers, including a single stack.

[0094] Each support band 292 includes a ring-like structure that surrounds the torsional transducer 218. The support band 292 includes an inner surface 293 and an outer surface 295. The support band 292 surrounds a bore 296. The torsional transducer 218 is received within the bore 296. The support band 292 surrounds the torsional transducer 218 in a supporting manner, such as to support or prevent radial expansion of the torsional transducer 218. In an exemplary embodiment, the inner diameter (at the inner surface 293) of the support band 292 may be equal to the outer diameter of the torsional transducer 218. The inner surface 293 connects with the outer surface of the torsional transducer 218. In an exemplary embodiment, the support band 292 supports the torsional transducer 218. The support band 292 may prevent the torsional transducer 218 from stretching. For example, the support band 292 may prevent stretching of the torsional transducer 218 during operation of the torsional transducer and / or cleaning of the components, such as in an autoclave for sterilization. The support band 292 may prevent stretching of the torsional transducer 218 to maintain the operating characteristics of the torsional transducer 218 and reduce the risk of depolarization of the torsional transducer 218 due to thermal expansion, etc.

[0095] In an exemplary embodiment, the support band 292 is fabricated from a rigid material, such as a metal material. In various embodiments, the support band 292 is fabricated from an aluminum or aluminum alloy material. In an exemplary embodiment, the support band 292 is fabricated from a material having a stiffness greater than the stiffness of the material of the torsional transducer 218. The support band 292 has a longitudinal width approximately equal to the width of the torsional transducer 218. In alternative embodiments, the support band 292 may be configured to support multiple torsional transducers 218, such as supporting a stack of torsional transducers 218. In an exemplary embodiment, the support band 292 is fabricated from a material configured to be processed through an autoclave, such as for sterilization. The support band 292 is configured to withstand high pressures and high temperatures. The support band 292 is configured to support the torsional transducer 218 in an autoclave, such as supporting the torsional transducer 218 when exposed to high pressures and high temperatures.

[0096] The support band 292 may be made from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. In various other embodiments, the support band 292 may be fabricated from non-metallic materials such as polymer composites, carbon fiber materials, high strength plastic materials, and the like.

[0097] In the illustrated embodiment, each torsional transducer 218 is a piezoelectric ring configured to convert electrical energy into ultrasonic vibrations and may hereinafter be referred to as a transducer ring. However, in alternative embodiments, the torsional transducer may have other shapes, such as a disk or cylinder without a hollow bore therethrough. Each transducer 218 includes a second end face 234, a first end face 236, a generally annular outer surface 238, and a bore 240. A support band 292 surrounds the annular outer surface 238. The second and first end faces 234, 236 may each be generally smooth to increase acoustic contact between the transducers 218 when assembled. For example, the second and first end faces 234, 236 may each be polished to a surface roughness in the range of approximately 2Ra to 6Ra without any coating. In alternative embodiments, each ring may include a coating (not shown) of a predetermined thickness on one or more of its surfaces. The coating may be made from a conductive material such as aluminum, aluminum alloy, silver, silver alloy, copper, copper alloy, gold, gold alloy, platinum, platinum alloy, tin, tin alloy, palladium, palladium alloy, nickel, nickel alloy, beryllium, beryllium alloy, tungsten, tungsten alloy, steel, chromium, chromium alloy, titanium, titanium alloy, etc.

[0098] The dimensions of the transducer 218 are predetermined to achieve the appropriate piezoelectric effect. For example, the transducer 218 may have a thickness of approximately 0.145 to 0.215 inches. However, alternative embodiments may have a thickness less than 0.145 inches or greater than 0.215 inches. For example, the transducer 218 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 240 of the transducer 218 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches.

[0099] In exemplary embodiments, one or more of the torsional transducers 218 may be fabricated from a piezoelectric ceramic material, such as a perovskite material, a lead zirconate titanate ("PZT") material, a piezo-electric material, a PXE 5 grade material, a PXE 52 grade material, a PXE 59 grade material, a PXE 21 grade material, a PXE 41 grade material, a PXE 42 grade material, a PXE 43 grade material, or a PXE 71 grade material. Alternatively, each transducer may be fabricated from a material having a crystal structure without a center of symmetry, such as a perovskite crystal structure. In one or more embodiments, each torsional transducer 218 may be fabricated from a material having a tetragonal lattice element cell below the Curie temperature of the material, e.g., a cubic lattice element cell above the Curie temperature of the material.

[0100] In the exemplary embodiment, the inert ring 222 includes a second end surface 242, a first end surface 244, a generally annular outer surface 246, and a bore 248. The dimensions and materials of the transducer 218 are predetermined to achieve the appropriate configuration of the standing wave 100 along the central axis A and the corresponding locations of the nodes 102 and anti-nodes 104. For example, the inert ring 222 may have a thickness of approximately 0.265 to 0.385 inches. However, alternative embodiments may have thicknesses less than 0.265 inches or greater than 0.385 inches. For example, the inert ring 222 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 248 of the inert ring 222 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches.

[0101] In one or more embodiments, the inert ring 222 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the inert ring 222 may be made from titanium, titanium alloys, aluminum, aluminum alloys, copper, copper alloys, iron, iron alloys, nickel, nickel alloys, silver, silver alloys, cobalt, cobalt alloys, tin, tin alloys, gold, gold alloys, tungsten, tungsten alloys, beryllium, beryllium alloys, platinum, platinum alloys, chromium, chromium alloys, lead, lead alloys, palladium, palladium alloys, zinc, zinc alloys, rhodium, rhodium alloys, niobium, niobium alloys, vanadium, vanadium alloys, manganese, manganese alloys, indium and indium alloys, tantalum, tantalum alloys, molybdenum, molybdenum alloys, cadmium, cadmium alloys, thallium, thallium alloys, ruthenium, ruthenium alloys, iridium, iridium alloys, gallium, gallium alloys, osmium, osmium alloys, rhenium, rhenium alloys, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the inert ring 222 may be fabricated from a damping material, a material with a Q factor greater than 0.5, a metal alloy in an annealed state, a titanium alloy in an annealed state, or from Ti-6A1-4V ultra-low interstitial quality in an annealed state.

[0102] In the exemplary embodiment, each electrode 220 is generally ring-shaped and includes a second end surface 250, a first end surface 252, a generally annular outer surface 254, and a bore 256. One or more of the electrodes may include leads 258 that operably connect to the control system 14 via electrical connections 30 of the connection assembly 16 (FIG. 11). The dimensions of the transducer 218 are predetermined to achieve proper connection between the components. For example, the electrodes 220 may have a thickness of approximately 0.700 to 0.900 inches. However, alternative embodiments may have a thickness less than 0.700 inches or greater than 0.900 inches. For example, the electrodes 220 may have an outer diameter of approximately 0.465 to 0.655 inches. However, alternative embodiments of the present invention may have an outer diameter less than 0.465 inches or greater than 0.655 inches. For example, the bore 256 of the electrode 220 may have a diameter of approximately 0.175 to 0.375 inches. However, alternative embodiments may have a diameter less than 0.175 inches or greater than 0.375 inches. One or more of the electrodes 220 may be fabricated from aluminum, an aluminum alloy, silver, a silver alloy, copper, a copper alloy, gold, a gold alloy, platinum, a platinum alloy, tin, a tin alloy, palladium, a palladium alloy, nickel, a nickel alloy, beryllium, a beryllium alloy, tungsten, a tungsten alloy, steel, chromium, a chromium alloy, titanium, a titanium alloy, or the like.

[0103] In the illustrative embodiment, connector block 202 is a generally cylindrical component having a second end 260 configured to removably connect with connection assembly 16 and a first end 262 configured to mate with transducer assembly 210. An outer surface 264 of connector block 202 is configured to receive an O-ring that forms a hermetic seal with housing 110 ( FIG. 15 ). A suction bore 266 extends through connector block 202 having an inlet 268 at second end 260 for mating with suction barb 82 and an outlet 270 at first end 262 for mating with bore 290 of transducer assembly 210. An irrigation bore 272 extends through connector block 202 having an inlet 274 at second end 260 for mating with irrigation barb 52 and an outlet 276 at first end 262 for mating with irrigation channel 122. The dimensions of the transducer 218 are predetermined to achieve the proper configuration of the standing wave 100 and corresponding positions of the nodes 102 and anti-nodes 104 .

[0104] In one or more embodiments, the connector block 202 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the connector block 202 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, the connector block 202 may be fabricated from a damping material, a material with a Q factor greater than 0.5, a metal alloy in an annealed state, a titanium alloy in an annealed state, or from Ti-6A1-4V ultra-low interstitial quality in an annealed state.

[0105] In the exemplary embodiment, amplifier 206 is a generally cylindrical component having a first end 284 configured to removably connect with surgical attachment 300 and a second end 286 configured to mate with transducer assembly 210 (FIG. 15). The dimensions of amplifier 206 are predetermined to achieve the appropriate configuration of standing wave 100 and corresponding locations of nodes 102 and anti-nodes 104.

[0106] In one or more embodiments, the amplifier 206 may be fabricated from any suitable material, including, but not limited to, a polymer, a metal, a metal alloy, or the like, or from any combination of suitable materials. For example, the amplifier 206 may be fabricated from titanium, titanium alloy, aluminum, aluminum alloy, copper, copper alloy, iron, iron alloy, nickel, nickel alloy, silver, silver alloy, cobalt, cobalt alloy, tin, tin alloy, gold, gold alloy, tungsten, tungsten alloy, beryllium, beryllium alloy, platinum, platinum alloy, chromium, chromium alloy, lead, lead alloy, palladium, palladium alloy, zinc, zinc alloy, rhodium, rhodium alloy, niobium, niobium alloy, vanadium, vanadium alloy, manganese, manganese alloy, indium and indium alloy, tantalum, tantalum alloy, molybdenum, molybdenum alloy, cadmium, cadmium alloy, thallium, thallium alloy, ruthenium, ruthenium alloy, iridium, iridium alloy, gallium, gallium alloy, osmium, osmium alloy, rhenium, rhenium alloy, stainless steel, brass, bronze, duralumin, or nitinol. Illustratively, amplifier 206 may be fabricated from a damping material, a material with a Q factor greater than 0.5, an annealed metal alloy, an annealed titanium alloy, or an annealed Ti-6A1-4V ultra-low interstitial quality.

[0107] It should be understood that the above description is intended to be illustrative, and not limiting. For example, the above-described embodiments (and / or aspects thereof) can be used in combination with each other. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the subject matter described herein without departing from its scope. While the dimensions and types of materials described herein are intended to define the parameters of the disclosed subject matter, they are by no means limiting and are exemplary embodiments. Many other embodiments will become apparent to those skilled in the art upon review of the above description. Therefore, the scope of the subject matter described herein should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Further, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects. Moreover, the following claim limitations are not written in means-plus-function form, and such claim limitations are not intended to be construed under 35 U.S.C. §112(f) unless additional construction following the phrase "means for" is expressly used.

[0108] As used herein, elements or steps listed in the singular and followed by the word "a" or "an" should be understood not to exclude a plural of said elements or steps, unless such exclusion is expressly stated. Furthermore, references to "one embodiment" of the subject matter described herein are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Furthermore, unless expressly stated to the contrary, embodiments "comprising" or "having" one or more elements having a particular characteristic may include additional such elements that do not have that characteristic.

[0109] This written description uses examples to disclose some embodiments of the subject matter described herein, including the best mode, and also enables those skilled in the art to practice embodiments of the disclosed subject matter, including making and using the devices or systems, and performing the methods. The patentable scope of the subject matter described herein is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that have insubstantial differences from the literal language of the claims.

[0110] The foregoing description of specific embodiments of the inventive subject matter will be better understood when read in conjunction with the accompanying drawings. To the extent that the drawings illustrate diagrams of functional blocks of various embodiments, the functional blocks are not necessarily indicative of a division between hardware circuitry. Thus, for example, one or more of the functional blocks (e.g., a communication unit, a control system, etc.) may be implemented by a single piece of hardware (e.g., a general-purpose signal processor, a microcontroller, a random access memory, a hard disk, etc.). Similarly, a program may be a stand-alone program, may be incorporated as a subroutine within an operating system, may be a function within an installed software package, and the like. The various embodiments are not limited to the arrangements and instrumentality shown in the drawings.

[0111] Because certain changes can be made to the above-described systems and methods without departing from the spirit and scope of the inventive subject matter contained herein, it is intended that all subject matter in the above description or shown in the accompanying drawings should be construed as merely examples illustrating the inventive concepts herein and not as limiting the inventive subject matter.

[0112] Changes may be made in the above structure without departing from the scope of the present disclosure, and it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted in an illustrative and not a limiting sense.

Claims

1. A surgical handpiece, comprising: a motor including a torsional transducer assembly along a central axis of the surgical handpiece, the motor configured for operable connection to a power source, the torsional transducer assembly including a plurality of torsional transducers, each torsional transducer including a support band surrounding the torsional transducer; a surgical attachment including a first end removably connected to the motor and a second end defining a working surface for engaging biological tissue.

2. The surgical handpiece of claim 1 , wherein the support band comprises a ring-like structure including an inner surface that engages an outer surface of the torsional transducer to support the torsional transducer.

3. 3. A surgical handpiece according to claim 1 or 2, wherein the support band is made of a metallic material, preferably aluminum or an aluminum alloy.

4. 4. The surgical handpiece of claim 1, wherein the support band has a width and the torsional transducer includes a width, the width of the support band being approximately equal to the width of the torsional transducer.

5. The surgical handpiece according to any one of claims 1 to 4, wherein the support band has a stiffness greater than a stiffness of the torsional transducer.

6. 6. The surgical handpiece of claim 1, wherein the motor is configured to generate a standing wave along the central axis in response to application of current and voltage from the power source, the standing wave defining an alternating pattern of nodes and anti-nodes along the central axis, the location of one of the anti-nodes along the central axis corresponding to the location of the working surface.

7. 7. The surgical handpiece of claim 6, wherein the surgical attachment has a joint along the central axis at a location relative to one of the nodes to increase the amplitude of the standing wave at the working surface.

8. 8. The surgical handpiece of claim 1, wherein each torsional transducer includes an end face having a surface roughness configured for acoustic contact with an end face of another torsional transducer, or each torsional transducer includes a piezoelectric ring.

9. 9. The surgical handpiece of claim 1, wherein the torsional transducer is configured to vibrate the ultrasonic tip of the surgical attachment in a torsional motion about the central axis or to operate as a full wavelength resonator along the central axis of the handpiece.

10. 10. The surgical handpiece of claim 1, wherein the torsional transducer assembly includes a first stack of torsional transducers and a second stack of torsional transducers opposed to each other about an interface.

11. 11. The surgical handpiece of claim 1, wherein the surgical attachment comprises an ultrasonic tip, the ultrasonic tip comprising a plurality of tines configured to correspond to a resonant frequency as a function of peak-to-peak amplitude, or the surgical attachment comprises an angled adapter.

12. The motor 12. The surgical handpiece of claim 1, further comprising a connector block aligned along the central axis of the surgical handpiece, and an amplifier aligned along the central axis of the surgical handpiece.

13. A surgical handpiece, comprising: a motor including a torsion transducer assembly along a central axis of the surgical handpiece, the motor configured for operative connection to a power source, the torsion transducer assembly including a torsion transducer stack including a plurality of torsion transducers stacked end-to-end, bolts holding the torsion transducers within the torsion transducer stack, support bands surrounding the corresponding torsion transducers, and sets of electrodes electrically connected to the corresponding torsion transducers; a surgical attachment including a first end removably connected to the motor and a second end defining a working surface, the surgical attachment including an ultrasonic tip on the working surface for engaging biological tissue.

14. A surgical handpiece, comprising: a plurality of torsional transducers along a central axis of the surgical handpiece, the plurality of torsional transducers being configured for operative connection to a power source; a support band surrounding the corresponding torsion transducer for supporting the corresponding torsion transducer; a surgical attachment operably coupled to the plurality of torsional transducers, the surgical attachment including an ultrasonic tip at a working surface for engaging biological tissue; the plurality of torsional transducers are configured to generate standing waves along the central axis in response to application of current and voltage from the power source, the standing waves defining an alternating pattern of nodes and anti-nodes along the central axis, the location of one of the anti-nodes along the central axis corresponding to the location of the working surface.

15. 20. The surgical handpiece of claim 18, wherein the torsional transducer is configured to vibrate the ultrasonic tip of the surgical attachment in a torsional motion about the central axis.

16. 20. The surgical handpiece of claim 18 or 19, wherein the support band comprises a ring-like structure including an inner surface that engages an outer surface of the torsional transducer to support the torsional transducer.

17. The surgical handpiece of any one of claims 18 to 20, wherein the support band has a stiffness greater than a stiffness of the torsional transducer.

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