BR112019003619B1 - ULTRASONIC TRANSDUCER SET - Google Patents

Abstract

The present invention relates to various ultrasonic instruments. Ultrasonic instruments include an ultrasonic waveguide acoustically coupled to an ultrasonic transducer. Various techniques for acoustically coupling the ultrasonic transducer to the ultrasonic waveguide are described.

Description

PRIORITY

[001] This application claims the benefit of U.S. Provisional Application Serial No. 62/379,550, filed August 25, 2016, which is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

[002] The present invention relates, in general, to ultrasonic surgical instruments and, more particularly, to ultrasonic transducers to drive ultrasonic waveguides. Ultrasonic instruments, including both hollow core and solid core instruments, are used for the safe and effective treatment of many medical conditions. Ultrasonic instruments, and particularly solid-core ultrasonic instruments, are advantageous in that they can be used to cut and/or coagulate organic tissue using energy in the form of mechanical vibrations transmitted to a surgical tip actuator at ultrasonic frequencies. Ultrasonic vibrations, when transmitted to organic tissues at appropriate energy levels and using a suitable tip actuator, can be used to cut, dissect, elevate or cauterize tissue or separate muscle tissue from bone. Ultrasonic instruments using solid core technology are particularly advantageous because of the amount of ultrasonic energy that can be transmitted from the ultrasonic transducer, through a waveguide, and into the surgical tip actuator. These instruments can be used for open procedures or minimally invasive procedures such as laparoscopic or endoscopic procedures, where the end actuator passes through a trocar to reach the surgical site.

[003] Activation or excitation of the end actuator (eg, cutting blade) of such instruments at ultrasonic frequencies induces longitudinal vibratory motion that generates localized heat within adjacent tissue. Due to the nature of ultrasonic instruments, a particular ultrasonic actuated end actuator can be designed to perform numerous functions including, for example, cutting and coagulation. Ultrasonic vibration is induced in the surgical end actuator by electrically exciting a transducer, for example. The transducer may be constructed from one or more piezoelectric or magnetostrictive elements in the instrument handpiece. Vibrations generated by the transducer are transmitted to the surgical end actuator through an ultrasonic waveguide extending from the transducer to the surgical end actuator. The waveguide and end actuator are designed to resonate at the same frequency as the transducer. Therefore, when an end actuator is attached to a transducer, the total system frequency is the same as the frequency of the transducer itself.

[004] The amplitude of the longitudinal ultrasonic vibration at the tip, d, of the end actuator behaves as a simple sinusoid at the resonant frequency as given by: d= A sin(wt) where: w= the radian frequency that is equal a 2π times the cyclic frequency, f; and A= the range from zero to peak.

[005] The longitudinal excursion of the end actuator tip is defined as the peak-to-peak amplitude (p-t-p), which is just twice the amplitude of the sine wave or 2A. Often, the end actuator may comprise a blade which, due to longitudinal travel, may cut and/or coagulate tissue. U.S. Patent No. 6,283,981, which was issued on September 4, 2001 and is entitled METHOD OF BALANCING ASYMMETRIC ULTRASONIC SURGICAL BLADES; U.S. Patent No. 6,309,400, which was issued October 30, 2001 and is entitled CURVED ULTRASONIC WAVEGUIDE HAVING A TRAPEZOIDAL CROSS SECTION; and U.S. Patent No. 6,436,115, which issued on August 20, 2002 and is entitled BALANCED ULTRASONIC WAVEGUIDE INCLUDING A PLURALITY OF BALANCE ASYMMETRIES, the entire descriptions of which are hereby incorporated by reference, disclose various ultrasonic surgical instruments.

SUMMARY OF THE INVENTION

[006] In a general aspect, several aspects refer to an ultrasonic surgical instrument comprising a transducer configured to produce vibrations along a longitudinal axis of a surgical tool at a predetermined frequency. In various aspects, the surgical tool may include an ultrasonic waveguide that extends along the longitudinal axis and is coupled to the transducer. In various aspects, the surgical tool includes a body having a proximal end and a distal end, the distal end being movable with respect to the longitudinal axis by vibrations produced by the transducer, and the proximal end being mechanically coupled to the transducer.

[007] In one aspect, a compressed ultrasonic transducer assembly is provided. The compressed ultrasonic transducer assembly comprises a metal housing defining an aperture; at least two piezoelectric elements disposed within the aperture and compressed by a compressive force, wherein the at least two piezoelectric elements are configured to operate in a D33 mode; and a metal plug attached to the metal housing to close the opening and to maintain the at least two piezoelectric elements in a compressed state within the metal housing.

[008] In another aspect, an ultrasonic surgical system is provided. The ultrasonic surgical instrument comprises an ultrasonic waveguide; an ultrasonic transducer mounted to the ultrasonic waveguide and configured to operate in a D31 mode, the ultrasonic transducer comprising: a first ceramic piezoelectric element having a first side attached to a first side of the ultrasonic waveguide by a first material binding; and a second piezoelectric ceramic element having a first side secured to a second side of the ultrasonic waveguide by the first bonding material, the first side of the ultrasonic waveguide being opposite the second side of the ultrasonic waveguide.

[009] In another aspect, an ultrasonic surgical system is provided. The ultrasonic surgical instrument comprises an ultrasonic waveguide comprising: a base portion; first and second walls extending from one side of the base portion; and first and second projections projecting from corresponding first and second walls, a first space being defined between the first projection and the base portion and a second space being defined between the second projection and the base portion base; and an ultrasonic transducer attached to the ultrasonic waveguide, the ultrasonic transducer comprising at least one piezoelectric element slidably disposed between and attached to the first and second spaces.

[0010] In another aspect, an ultrasonic surgical instrument is provided. The ultrasonic surgical instrument comprises an ultrasonic waveguide; and an ultrasonic transducer attached to the ultrasonic waveguide; the ultrasonic waveguide comprising a tuning fork-like structure comprising: an upper yoke; and a lower yoke defining a U-shaped opening therebetween configured to receive the ultrasonic transducer therein.

FIGURES

[0011] The features of the various aspects are presented with particularity in the attached claims. However, the various aspects, both in regard to organization and methods of operation, together with the objects and further advantages thereof, may be better understood by reference to the following description, taken in conjunction with the accompanying drawings, of the following way:

[0012] Figure 1 illustrates an ultrasonic surgical instrument system in accordance with an aspect of this disclosure.

[0013] Figures 2A to 2C illustrate a piezoelectric transducer in accordance with an aspect of this disclosure.

[0014] Figure 3 illustrates a D31 ultrasonic transducer architecture that includes an ultrasonic waveguide and one or more piezoelectric elements attached to the ultrasonic waveguide in accordance with an aspect of the present disclosure.

[0015] Figures 4A to 4C illustrate an ultrasonic transducer assembly compressed into a D33 configuration with compression tuned in accordance with an aspect of this disclosure.

[0016] Figure 5 is a perspective view of an ultrasonic surgical instrument in accordance with an aspect of this description.

[0017] Figure 6 is a perspective view of a piezoelectric element for use with the ultrasonic surgical instrument shown in Figure 5 in accordance with an aspect of the present disclosure.

[0018] Figure 7 is a cross-sectional view of the ultrasonic surgical instrument shown in Figure 5 in accordance with an aspect of the present description.

[0019] Figure 8 illustrates an example of an adhesive bond between a metal and a metal alloy solder in accordance with an aspect of this disclosure.

[0020] Figure 9 illustrates an adhesive bond between a ceramic and a metal formed by a metal alloy solder in accordance with an aspect of this disclosure.

[0021] Figure 10 illustrates an example of a metallurgical/chemical bond in accordance with an aspect of this disclosure.

[0022] Figure 11 is a microstructure illustration of a metal alloy and ceramic solder chemical bonding in accordance with an aspect of this disclosure.

[0023] Figure 12A illustrates an ultrasonic surgical instrument prior to assembly and polarization in accordance with an aspect of this disclosure.

[0024] Figure 12B illustrates the ultrasonic surgical instrument of Figure 12A. prior to polarization and first and second non-polarized piezoelectric elements attached to the ultrasonic waveguide in a D31 configuration in accordance with an aspect of this disclosure.

[0025] Figure 12C illustrates the ultrasonic instrument of Figure 12B before polarization and the first and second non-polarized piezoelectric elements attached to the ultrasonic waveguide in a D31 configuration, in accordance with an aspect of this description.

[0026] Figure 13A illustrates an ultrasonic surgical instrument that includes an ultrasonic waveguide configured to hold piezoelectric elements with the use of a binding material in accordance with an aspect of this disclosure.

[0027] Figure 13B illustrates an ultrasonic surgical instrument that includes an ultrasonic waveguide configured to hold piezoelectric elements with the use of a biasing force in accordance with an aspect of this disclosure.

[0028] Figure 13C illustrates an ultrasonic surgical instrument that includes an ultrasonic waveguide configured to grip piezoelectric elements using a combination of a bonding material and a biasing force in accordance with an aspect of this disclosure.

[0029] Figure 14 illustrates an ultrasonic surgical instrument comprising an ultrasonic waveguide attached to piezoelectric elements arranged in a D31 in accordance with an aspect of this description.

[0030] Figure 15 illustrates the ultrasonic surgical instrument shown in Figure 14 with a voltage V applied to the piezoelectric elements during a binding phase in accordance with an aspect of this description.

[0031] Figure 16 illustrates a D31 ultrasonic surgical instrument that includes piezoelectric elements attached on one side to an ultrasonic waveguide by a conductive adhesive and attached on the other side to electrically conductive plates by a conductive adhesive in accordance with an aspect of this description .

[0032] Figure 17 illustrates an ultrasonic surgical instrument that includes a single midplane ultrasonic transducer and an ultrasonic waveguide with a tuning fork-like structure in accordance with an aspect of the present disclosure.

[0033] Figure 18 is a cross-sectional view of the ultrasonic surgical instrument shown in Figure 17 with the ultrasonic transducer inserted into the tuning fork-like structure of the ultrasonic waveguide in accordance with an aspect of this description.

[0034] Figures 19A and 19B illustrate a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0035] Figure 20 illustrates a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0036] Figure 21 illustrates a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0037] Figures 22A to 22D illustrate a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0038] Figure 23 illustrates a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0039] Figure 24A illustrates a cross-sectional view of an ultrasonic transducer configuration D31 along line 24A-24A in accordance with an aspect of this description.

[0040] Figure 24B illustrates a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0041] Figure 24C illustrates the change in housing format of the D31 ultrasonic transducer configuration shown in Figures 24A to 24B in accordance with an aspect of this description.

[0042] Figures 25A to 25E illustrate a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0043] Figure 26A illustrates a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0044] Figure 26B illustrates the cap of the ultrasonic transducer configuration shown in Figure 26A in accordance with an aspect of this description.

[0045] Figures 26C to 26D illustrate a method of installing the D33 ultrasonic transducer configuration shown in Figure 26A in accordance with an aspect of this description.

[0046] Figure 27 illustrates a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0047] Figure 28 illustrates a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0048] Figures 29A to 29B illustrate a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0049] Figure 30A illustrates a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0050] Figure 30B illustrates an exploded view of the D31 ultrasonic transducer configuration shown in Figure 30A in accordance with an aspect of this description.

[0051] Figure 30C illustrates a D31 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0052] Figure 30D illustrates an exploded view of the D31 ultrasonic transducer configuration shown in Figure 30C in accordance with an aspect of this description.

[0053] Figure 31 illustrates a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0054] Figures 32A to 32B illustrate D31 ultrasonic transducer configurations having asymmetrically excitable piezoelectric transducer assemblies in accordance with an aspect of this disclosure.

[0055] Figures 33A to 33C illustrate D31 ultrasonic transducer configurations having asymmetrically excitable piezoelectric transducer assemblies in accordance with an aspect of this disclosure.

[0056] Figures 34A to 34B illustrate an ultrasonic transducer configuration D31, in which the piezoelectric elements are displaced relative to each other in accordance with an aspect of this disclosure.

[0057] Figures 34C to 34D illustrate plan views of an end actuator of a surgical instrument subjected to longitudinal and non-longitudinal movement, respectively, in accordance with an aspect of this description.

[0058] Figure 35A illustrates a perspective view of a distal end of a waveguide of a surgical instrument having complex features in accordance with an aspect of this disclosure.

[0059] Figures 35B to 35E illustrate a process for manufacturing the surgical instrument shown in Figure 35A in accordance with an aspect of this disclosure.

[0060] Figure 36A illustrates a perspective view of an ultrasonic transducer configuration D31 configured to generate non-longitudinal movement in accordance with an aspect of this description.

[0061] Figure 36B illustrates a perspective view of an electrode of the D31 ultrasonic transducer configuration shown in Figure 36A in accordance with an aspect of this description.

[0062] Figure 36C illustrates a cross-sectional view of the ultrasonic transducer configuration D31 shown in Figure 36A along line 36C-36C in accordance with one aspect of this description.

[0063] Figure 36D illustrates a side view of the electrode and piezoelectric transducer assembly of the D31 ultrasonic transducer configuration shown in Figure 36A in accordance with an aspect of this description.

[0064] Figure 37 illustrates a perspective view of an electrical connector with an ultrasonic signal generator for a surgical instrument, in accordance with an aspect of this description.

[0065] Figure 38 illustrates an exploded view of a D33 ultrasonic transducer configuration in accordance with an aspect of this disclosure.

[0066] Figure 39 illustrates a perspective view of the D33 ultrasonic transducer configuration of Figure 38 in accordance with an aspect of this description.

[0067] Figure 40 illustrates a perspective cross-sectional view of the ultrasonic transducer configuration D33 of Figure 38 in accordance with an aspect of this description.

[0068] Figure 41 illustrates a cross-sectional view of the D33 ultrasonic transducer configuration of Figure 38 in accordance with an aspect of this description.

DESCRIPTION

[0069] Before explaining the various aspects in detail, it should be noted that such aspects are not limited, in their application or use, to the details of construction and arrangement of parts illustrated in the attached drawings and in the description. The illustrative aspects may be implemented or incorporated in other aspects, variations and modifications and may be practiced or performed in a variety of ways. For example, the surgical instruments disclosed below are illustrative only and are not intended to limit their scope or application. Furthermore, unless otherwise indicated, the terms and expressions employed in the present invention have been chosen for the purpose of describing the illustrative aspects for the convenience of the reader and not to limit the scope thereof.

[0070] Certain aspects will now be described to provide a full understanding of the principles of structure, function, fabrication and use of the devices and methods disclosed in the present invention. One or more examples of these aspects are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are exemplary non-limiting aspects and that the scope of the various aspects is defined only by the claims. Features illustrated or described in relation to one aspect may be combined with features from other aspects. Such modifications and variations are intended to be included within the scope of the appended claims.

[0071] Various aspects described here refer, in general, to ultrasonic surgical instruments and blades for use therewith. Examples of ultrasonic surgical instruments and blades are disclosed in US Pat. 5,322,055; 5,954,736; 6,309,400; 6,278,218; 6,283,981; 6,325,811; and 8,319,400, the full disclosures of which are incorporated by reference into the present invention.

[0072] In many respects, an ultrasonic instrument comprising a surgical tool having an end actuator such as a blade may be of specific benefit, inter alia, in orthopedic procedures where it is desirable to remove cortical bone and/or tissue while controls bleeding. Due to its cutting and coagulation characteristics, a blade of an ultrasonic surgical instrument can be useful for cutting and coagulating general soft tissue. In certain circumstances, a blade in various aspects can be useful for simultaneously cutting and hemostatically sealing or cauterizing tissue. A blade can be straight or curved and useful for open or laparoscopic applications. A blade in many respects can be useful in spinal surgery, especially to aid posterior access in removing muscle from bone.

[0073] The applicant for this application holds the following patent applications filed simultaneously with this application and which are each incorporated herein by reference in their respective entireties:

[0074] attorney's document No. END7919USNP/160045M, entitled Ultrasonic Transducer Techniques for Ultrasonic Surgical Instrument, by inventors Jeffrey Messerly et al. deposited on August 17, 2017.

[0075] Attorney's document No. END7919USNP1/160045-1, entitled "Ultrasonic Transducer For Surgical Instrument", by inventors Jeffrey Messerly et al. deposited on August 17, 2017.

[0076] attorney's document no. END7919USNP2/160045-2, titled "Electrical And Thermal Connections For Ultrasonic Transducer" by inventors Jeffrey Messerly et al. filed on August 17, 2017.

[0077] attorney's document No. END7919USNP4/160045-4, entitled "Ultrasonic Transducer to Waveguide Joining" by inventors Jeffrey Messerly et al. filed on August 17, 2017.

[0078] attorney's document no. END7919USNP5/160045-5 entitled "Tissue Loading Of A Surgical Instrument" by inventors Jeffrey Messerly et al. deposited on August 17, 2017.

[0079] Figure 1 illustrates an aspect of an ultrasonic system 10. An aspect of the ultrasonic system 10 comprises an ultrasonic signal generator 12 coupled to an ultrasonic transducer 14, a handpiece assembly 60 comprising a handpiece compartment 16 and an end actuator 50. The ultrasonic transducer 14, which is known as a "Langevin stack", generally includes a transducer portion 18, a first resonator or posterior bell 20, and a second resonator or anterior bell 22 and auxiliary components. In various aspects, the ultrasonic transducer 14 is preferably an integral number of half the system wavelengths (nA/2) in length as will be described in more detail below. An acoustic assembly 24 may include the ultrasonic transducer 14, a crimp 26, a velocity transformer 28 and a surface 30.

[0080] It is noted that the terms "proximal" and "distal" are used here with reference to the act of the physician holding the handpiece assembly 60. Thus, the end actuator 50 is distal to the handpiece assembly more proximal handpiece 60. It is also noted that, for the sake of convenience and clarity, spatial terms such as "top" and "bottom" are also used in the present invention in relation to the act of the physician holding the handpiece assembly 60. However, surgical instruments are used in many orientations and positions, and such terms are not intended to be limiting and absolute.

[0081] The distal end of the posterior bell 20 is connected to the proximal end of the transduction portion 18 and the proximal end of the anterior bell 22 is connected to the distal end of the transduction portion 18. The anterior bell 22 and the posterior bell 20 have a length determined by several variables, including the thickness of the transducing portion 18, the density and modulus of elasticity of the material used to manufacture the posterior bell 20 and anterior bell 22, and the resonant frequency of the ultrasonic transducer 14. The anterior bell 22 it may be tapered inwardly from its proximal end to its distal end to amplify the amplitude of the ultrasonic vibration of the speed transformer 28 or, alternatively, the anterior bell 22 may have no amplification at all.

[0082] Referring again to Figure 1, the posterior bell 20 may include a threaded member extending therefrom which may be configured to be threadably engaged with a threaded opening in the anterior bell 22. In various aspects, elements piezoelectric elements, such as piezoelectric elements 32, for example, can be squeezed between the back bell 20 and the front bell 22 when the back bell 20 and the front bell 22 are assembled together. The piezoelectric elements 32 may be manufactured from any suitable material, such as, for example, lead zirconate titanate, lead metaniobate, lead titanate and/or any suitable piezoelectric crystal material, for example.

[0083] In various aspects, as discussed in more detail below, the transducer 14 may further comprise electrodes, such as positive electrodes 34 and negative electrodes 36, for example, which may be configured to create a voltage potential across one or more elements piezoelectric elements 32. Each of the positive electrodes 34, negative electrodes 36, and piezoelectric elements 32 may comprise a hole extending through the center that may be configured to receive the threaded member of the posterior bell 20. In various aspects, the positive and negative 34 and 36 are electrically coupled to wires 38 and 40, respectively, and wires 38 and 40 can be enclosed within a cable 42 and electrically connectable to the ultrasonic signal generator 12 of the ultrasonic system 10.

[0084] In various aspects, the ultrasonic transducer 14 of the acoustic assembly 24 converts the electrical signal from the ultrasonic signal generator 12 into mechanical energy that results in mainly longitudinal vibratory motion of the ultrasonic transducer 14 and the end actuator 50 at ultrasonic frequencies. A suitable generator is available under model number GEN11 from Ethicon EndoSurgery, Inc. of Cincinnati, Ohio, USA. When the acoustic assembly 24 is energized, a standing wave of vibratory motion is generated through the acoustic assembly 24. A suitable vibrational frequency range may be about 20 Hz to 120 kHz, and a well suited vibrational frequency range may be about 30 to 70 kHz and an exemplary operational vibrational frequency might be approximately 55.5 kHz.

[0085] The amplitude of the vibratory motion at any point along the acoustic array 24 may depend on the location along the acoustic array 24 at which the vibratory motion is measured. A pass through a minimum or zero value in the standing wave of vibratory motion is often called a node (that is, where the motion is normally minimal), and a maximum or peak of absolute value in the standing wave is often called a node. antinode (for example, where movement is normally maximum). The distance between an antinode and its nearest node is a quarter of a wavelength (À/4).

[0086] As outlined above, wires 38 and 40 transmit an electrical signal from the ultrasonic signal generator 12 to the positive electrodes 34 and to the negative electrodes 36. The piezoelectric elements 32 are energized by the electrical signal provided from the signal generator ultrasonic 12 in response to a pedal switch 44, for example to produce an acoustic standing wave in the acoustic assembly 24. The electrical signal causes disturbances in the piezoelectric elements 32 in the form of repeated small displacements, resulting in large compressive forces inside the material. The repeated small displacements cause the piezoelectric elements 32 to continuously expand and contract along the geometric axis of the voltage gradient, producing longitudinal waves of ultrasonic energy.

[0087] In various respects, the ultrasonic energy produced by the transducer 14 can be transmitted through the acoustic assembly 24 to the end actuator 50 through an ultrasonic transmission waveguide 46. For the acoustic assembly 24 to distribute energy to the actuator end end 50, acoustic assembly components 24 are acoustically coupled to end actuator 50. For example, the distal end of ultrasonic transducer 14 may be acoustically coupled, at surface 30, to the proximal end of ultrasonic transmission waveguide 46 by a threaded connection, such as a 48 screw.

[0088] The components of the acoustic set 24 can be acoustically tuned so that the length of any set is an integral number of half the wavelengths (nÀ/2), where the wavelength À is the wavelength of an operational or preselected longitudinal vibration drive frequency fd of the acoustic array 24 and where n is any positive integer. It is also contemplated that acoustic assembly 24 may incorporate any suitable arrangement of acoustic elements.

[0089] The ultrasonic end actuator 50 may have a length substantially equal to an integral multiple of half the system wavelengths (À/2). A distal end 52 of the ultrasonic end actuator 50 may be disposed at, or at least close to, an antinode to provide maximum or at least near-maximum longitudinal excursion of the distal end. When the transducer assembly is energized, in various respects, the distal end 52 of the ultrasonic end actuator 50 can be configured to move in the range of, for example, approximately 10 to 500 microns peak-to-peak, and preferably in the range of range of approximately 30 to 150 microns at a predetermined vibrational frequency.

[0090] As outlined above, the ultrasonic end actuator 50 may be coupled to the ultrasonic transmission waveguide 46. In various aspects, the ultrasonic end actuator 50 and the ultrasonic transmission guide 46, as illustrated, are formed as one single unit construction from a material suitable for transmission of ultrasonic energy such as Ti6Al4V (a titanium alloy including aluminum and vanadium), aluminum, stainless steel and/or any other suitable material. Alternatively, the ultrasonic end actuator 50 may be separable (and of different composition) from the ultrasonic transmitting waveguide 46, and coupled, for example, by a screw, solder, glue, quick connect, or other suitable known methods. The ultrasonic transmission waveguide 46 can have a length substantially equal to an integral number of half system wavelengths (nA/2), for example. The ultrasonic transmitting waveguide 46 may preferably be fabricated from a solid core shaft constructed of material that propagates ultrasonic energy efficiently, such as a titanium alloy (i.e., Ti6Al4V) or an aluminum alloy, for example. .

[0091] In the aspect illustrated in Figure 1, the ultrasonic transmission waveguide 46 comprises a plurality of stabilizing silicone rings or conformable supports 56 positioned at, or at least close to, a plurality of nodes. Silicone rings 56 can dampen unwanted vibration and isolate ultrasonic energy from a sheath 58 that at least partially surrounds waveguide 46, thereby ensuring flow of ultrasonic energy in a longitudinal direction to distal end 52 end actuator 50 at maximum efficiency.

[0092] As shown in Figure 1, the sheath 58 can be attached to the distal end of the handpiece assembly 60. The sheath 58 generally includes an adapter or nosecone 62 and an elongated tubular member 64. The tubular member 64 is attached to and/or extends from adapter 62 and has a longitudinally extending opening therethrough. In various aspects, the sheath 58 may be threaded or press fit over the distal end of the housing 16. In at least one aspect, the ultrasonic transmission waveguide 46 extends through the opening of the tubular member 64 and the silicone rings 56 can come into contact with the side walls of the opening and isolate the ultrasonic transmission waveguide 46 there. In various aspects, the adapter 62 of the sheath 58 is preferably constructed from Ultem®, for example, and the tubular member 64 is fabricated from stainless steel, for example. In at least one aspect, the ultrasonic transmission waveguide 46 can have polymeric material, for example, surrounding it to insulate it from external contact.

[0093] As described above, a voltage, or power source, can be operationally coupled to one or more of the piezoelectric elements of a transducer, and a voltage potential applied to each of the piezoelectric elements can cause the piezoelectric elements to expand and contract, or vibrate, in a longitudinal direction. As also described above, the voltage potential may be cycled and, in various aspects, the voltage potential may be cycled at a frequency that is equal to or nearly equal to the resonant frequency of the component system comprising the transducer 14, the guide waveform 46 and end actuator 50, for example. In many respects, however, certain piezoelectric elements within the transducer may contribute more to the standing wave of longitudinal vibrations than other piezoelectric elements within the transducer. More particularly, a longitudinal elongation profile can develop within a transducer, where the elongation profile can control, or limit, the longitudinal displacements that some of the piezoelectric elements can contribute to standing wave vibrations, especially when the system is vibrating at or near its resonant frequency.

[0094] It may be recognized, with reference to the ultrasonic surgical instrument system 10 of Figure 1, that multiple components may be required to couple the mechanical vibrations of the piezoelectric elements 32 through the waveguide 46 to the end actuator 50. The additional elements comprising the acoustic assembly 24 can add additional fabrication costs, fabrication steps and complexity to the system. Aspects of an ultrasonic medical device are disclosed below that may require fewer components, manufacturing steps, and costs than the equivalent device illustrated in Figure 1 and as described above.

[0095] Again, with reference to Figure 1, the piezoelectric elements 32 are configured in a "Langevin" stack, in which the piezoelectric elements 32 and their activation electrodes 34 and 36 (together, the transducer 14) are sandwiched. The mechanical vibrations of the activated piezoelectric elements 32 propagate along the longitudinal axis of the transducer 14, and are coupled through the acoustic assembly 24 to the end of the waveguide 46. Such a mode of operation of a piezoelectric element is often described as the element D33 mode, especially for piezoelectric ceramic elements comprising, for example, lead zirconate-titanate, lead meta-niobate or lead titanate. The D33 mode of a ceramic piezoelectric element is illustrated in Figures 2A to 2C.

[0096] Figure 2A shows a piezoelectric element 200 manufactured from a piezoelectric ceramic material. A ceramic piezoelectric material is a polycrystalline material comprising a plurality of individual microcrystalline domains. Each microcrystalline domain has a polarization axis along which the domain can expand or contract in response to an imposed electric field. However, in a native ceramic, the polarization axes of the microcrystalline domains are randomly arranged, so that there is no net piezoelectric effect on the raw ceramic. A net reorientation of the polarization axes can be induced by subjecting the ceramic to a temperature above the Curie temperature of the material and placing the material in a strong electric field. Once the sample temperature drops below the Curie temperature, most of the individual polarization axes will be reoriented and fixed in a gross polarization direction. Figure 2A illustrates such a piezoelectric element 200 after being biased along the inductive electric field axis P. Although the unbiased piezoelectric element 200 does not have any useful piezoelectric axis, the biased element 200 can be described as having a bias axis d3 , parallel to the direction of the induction field axis P. For completeness, a geometry axis orthogonal to the d3 axis can be called a d1 axis. The dimensions of the piezoelectric element 200 are identified as length (L), width (W) and thickness (T).

[0097] Figures 2B and 2C illustrate the mechanical deformations of a piezoelectric element 200 that can be induced by subjecting the piezoelectric element 200 to an electric field of action E oriented along the geometric axis d3 (or P). Figure 2B illustrates the effect of an electric field E having the same direction as the bias field P along the d3 axis on a piezoelectric element 205. As illustrated in Figure 2B, the piezoelectric element 205 can deform by expanding along the d3 axis while compressing along the d1 axis. Figure 2C illustrates the effect of an electric field E that has the opposite direction to the bias field P along the d3 axis on a piezoelectric element 210. As illustrated in Figure 2C, the piezoelectric element 210 can deform by compressing itself when along the d3 axis, while expanding along the d1 axis. The vibrational coupling along the d3 axis during the application of an electric field along the d3 axis can be called D33 coupling or activation using a D33 mode of a piezoelectric element. The transducer 14 illustrated in Figure 1 uses the D33 mode of the piezoelectric elements 32 to transmit mechanical vibrations along the waveguide 46 to the end actuator 50. As the piezoelectric element also deforms along the axis d1, the vibrational coupling to the along the d1 axis while applying an electric field along the d3 axis can also be an effective source of mechanical vibrations. Such coupling may be called D31 coupling or activation using a D31 mode of a piezoelectric element.

[0098] As illustrated by Figures 2A to 2C, during operation in D31 mode, the transverse expansion of the piezoelectric elements 200, 205, 210 can be mathematically modeled by the following equation:

[0099] In the equation, L, W and T refer to the length, width and thickness dimensions of a piezoelectric element, respectively. Vd31 denotes the voltage applied to a piezoelectric element operating in D31 mode. The amount of transverse expansion resulting from the D31 coupling described above is represented by ΔL (ie, the expansion of the piezoelectric element along the length dimension) and ΔW (ie, the expansion of the piezoelectric element along the width dimension). Furthermore, the transverse expansion equation models the relationship between ΔL and ΔW and the applied voltage Vd31. Aspects of ultrasonic medical devices based on D31 activation by a piezoelectric element are disclosed below.

[00100] In various aspects, as described below, an ultrasonic medical device may comprise a transducer configured to produce longitudinal vibrations and a surgical tool having a transducer base plate (e.g., a transducer mounting portion) operatively coupled to the transducer, an end actuator and a waveguide between them. In certain aspects, as also described below, the transducer can produce vibrations that can be transmitted to the end actuator, which vibrations can drive the transducer base plate, waveguide, end actuator, and/or other various components of the medical ultrasonic device at or near resonant frequency. At resonance, a longitudinal stretching pattern, or longitudinal stress pattern, can develop within the transducer, waveguide and/or end actuator, for example. In many respects, such a longitudinal elongation pattern, or longitudinal stress pattern, can cause the longitudinal elongation, or longitudinal stress, to vary along the length of the transducer base plate, waveguide and/or end actuator, in a sinusoidal or at least substantially sinusoidal form. In at least one aspect, for example, the longitudinal elongation pattern can have maximum peaks and zero points, and the elongation values can vary in a non-linear manner between such peaks and zero points.

[00101] Figure 3 illustrates an ultrasonic surgical instrument 250 that includes an ultrasonic waveguide 252 attached to an ultrasonic transducer 264 by a binding material, in which the ultrasonic surgical instrument 250 is configured to operate in a D31 mode, according to with an aspect of the present disclosure. The ultrasonic transducer 264 includes first and second piezoelectric elements 254a, 254b attached to the ultrasonic waveguide 252 by a bonding material. The piezoelectric elements 254a, 254b include electrically conductive plates 256a, 256b for electrically coupling one pole of a suitable voltage source to drive the piezoelectric elements 254a, 254b (eg, generally a high voltage). The opposite pole of the voltage source is electrically coupled to the ultrasonic waveguide 252 by electrically conductive joints 258a, 258b. In one aspect, the electrically conductive plates 256a, 256b are coupled to a positive pole of the voltage source and the electrically conductive joints 258a, 258b are electrically coupled to ground potential through the metal ultrasonic waveguide 252. In one aspect, the ultrasonic waveguide 252 is produced from titanium or titanium alloy (i.e., Ti6Al4V) and the piezoelectric elements 254a, 254b are produced from an inorganic intermetallic compound of lead zirconate titanate with the chemical formula of Pb[ ZrxTii-x]O3 (0<x<1). Also called PZT, it is a ceramic perovskite material that shows a marked piezoelectric effect, meaning that the compound changes shape when an electric field is applied. It is used in various practical applications such as ultrasonic transducers and PZT piezoelectric resonators. The axis of polarization (P) of the piezoelectric elements 254a, 254b is indicated by the direction arrow 260. The axis of motion of the ultrasonic waveguide 252 in response to excitation of the piezoelectric elements 254a, 245b is shown by a motion arrow 262 at the distal end of the ultrasonic waveguide 252 is generally referred to as the ultrasonic blade portion of the ultrasonic waveguide 252. The axis of motion 262 is orthogonal to the axis of polarization (P) 260.

[00102] In conventional D33 ultrasonic transducer architectures, as shown in Figure 1, the screwed piezoelectric elements 32 use electrodes 34 and 36 to create an electrical contact with both sizes of each piezoelectric element 32. The D31 architecture 250, according to one aspect of the present disclosure, however, employs a different technique to create electrical contact with both sides of each piezoelectric element 254a, 254b. Various techniques for providing electrical contact with the piezoelectric elements 254a, 254b include bonding electrically conductive elements (e.g., wires) to the free surface of each piezoelectric element 254a, 254b for the high-potential connection and bonding each piezoelectric element 254a, 254b to the guide 252 ultrasonic waveform for grounding using solder, conductive epoxy, or other techniques described herein. Compression can be used to maintain electrical contact with the acoustic train without making a permanent connection. This can cause an increase in device thickness and must be controlled to avoid damaging the piezoelectric elements 254a, 254b. Low compression can damage piezoelectric elements 254a, 254b by spark gap and high compression can damage piezoelectric elements 254a, 254b by local mechanical wear. In other techniques, metal spring contacts can be employed to create electrical contact with the piezoelectric elements 254a, 254b. Other techniques may include sheet-on-foam gaskets, conductive foam, soldering. Electrical connection to both sides of piezoelectric elements 254a, 254b of acoustic train configuration D31. The electrical connection to ground can be made with the metal ultrasonic waveguide 252, which is electrically conductive, if there is electrical contact between the piezoelectric elements 254a, 254b and the ultrasonic waveguide 252.

[00103] In various aspects, as described below, an ultrasonic medical device may comprise a transducer configured to produce longitudinal vibrations and a surgical instrument having a transducer base plate operatively coupled to the transducer, an end actuator and a waveguide between the same. In certain aspects, as also described below, the transducer can produce vibrations that can be transmitted to the end actuator, which vibrations can drive the transducer base plate, waveguide, end actuator, and/or other various components of the ultrasonic medical device at or near a resonant frequency. At resonance, a longitudinal stretching pattern or longitudinal stress pattern can develop within the transducer, waveguide, and/or end actuator, for example. In many respects, such a longitudinal elongation pattern, or longitudinal stress pattern, can cause the longitudinal elongation, or longitudinal stress, to vary along the length of the transducer base plate, waveguide, and/or end actuator. , in a sinusoidal, or at least substantially sinusoidal, form. In at least one aspect, for example, the longitudinal elongation pattern can have maximum peaks and zero points, and the elongation values can vary non-linearly between such peaks and zero points.

[00104] In conventional D33 ultrasonic transducer architectures, as shown in Figure 1, a screw provides compression that acoustically couples the rings of piezoelectric elements to the ultrasonic waveguide. The D31 architecture 250, in accordance with one aspect of the present disclosure, employs a variety of different techniques to acoustically couple the piezoelectric elements 254a, 254b to the ultrasonic waveguide 252. These techniques are described later in this document.

[00105] Figures 4A to 4C illustrate a compressed ultrasonic transducer assembly 7000 in a D33 configuration with tuned compression, in accordance with an aspect of this disclosure. In one aspect, the ultrasonic transducer assembly 7000 includes one or more piezoelectric elements 7002a, 7002b, 7002c, 7002d (e.g., PZT) compressed into an aperture 7014 defined by a housing 7004 or housing. When the ultrasonic transducer assembly 7000 is fully compressed, it is fed into a further assembly process, in which, for example, a surface of one of the piezoelectric elements 7002a-d in the assembly 7000 is attached to an ultrasonic waveguide metal or waveguide. Applying compression to the 7002a-d piezoelectric elements (especially in the coupled elongation direction) provides greater efficiency and increased ability to drive larger loads. Since the compressed ultrasonic transducer assembly 7000 does not include an axially compressed element, the piezoelectric elements 7002a-d are compressed along the axis of vibration LA and then anchored in place. Housing 7004 or a band disposed around piezoelectric elements 7002a-d is compressed and the assembly is anchored in place as described below.

[00106] Figure 4A illustrates an installation phase of the 7000 ultrasonic transducer assembly in a pre-compression state. One or more piezoelectric elements 7002a-d are stacked within compartment 7004. A plug 7006 is aligned with the stack of piezoelectric elements 7002a-d. Housing 7004 and plug elements 7006 are produced from a metal material. Plug 7006 and stack of piezoelectric elements 7002a-d are aligned with the axis of vibration LA. The length of the stack of piezoelectric elements 7002a-d before compression is identified as d0.

[00107] Figure 4B illustrates an initial compression state of the compressed ultrasonic transducer assembly 7000. An initial target force Fi is applied to the plug 7006 to compress the plug 7006 over the stack of piezoelectric elements 7002a-d.

[00108] Figure 4C illustrates a final compression state of the compressed ultrasonic transducer assembly 7000. As shown in Figure 4C, after a final compression force Ff is applied to the stack of piezoelectric elements 7002a-d, the compartment 7004 and the plug are anchored together with the anchors 7008a, 7008b while the stack of piezoelectric elements 7002a-d is in the compressed state. The compressed length of the stack of piezoelectric elements 7002a-d is identified as d1, where d1<d0. Anchors 7008a, 7008b can be any suitable element that serves to hold plug 7006 to housing 7004 securely in place against piezoelectric elements 7002a-d to hold stack of piezoelectric elements 7002a-d under compression. Accordingly, the anchor 7008a, 7008b may be attached or secured by a joint which is formed by soldering, soldering, brazing, epoxy, tamping or any combination thereof.

[00109] In another aspect, the anchor 7008a, 7008b can be attached to the metallic compartment 7004 by threaded connection. In the configuration of a threaded connection, the metal housing 7004 and the metal plug 7006 each include a threaded end and the components are threaded together. In one aspect, metal plug 7006 includes external male threads and housing 7004 includes internal female threads for threadably engaging the male threads of plug 7006 and plug 7006 is threaded into the internal portion of housing 7004. In another aspect In this aspect, plug 7006 includes internal female threads and housing 7004 includes external male threads to threadably engage the female threads of plug 7006 and plug 7006 is threaded over the outer portion of housing 7004. In the last-mentioned configuration, the interior of the plug 7006 includes a protrusion or other feature that projects into the plug 7006 to contact and compress the stack of piezoelectric elements 7002a-c. In the threaded anchor configuration, a rotational force is applied to plug 7006, which applies a compressive force to stack of piezoelectric elements 7002a-d as plug 7006 is threadably engaged with housing 7004.

[00110] When the transducer assembly 7000 is completely compressed and the anchors 7008a, 7008b are applied, the transducer assembly 7000 is ready to be mounted. In one aspect, an ultrasonic waveguide is acoustically coupled to a first surface 7010 of transducer assembly 7000, and in another aspect, the ultrasonic waveguide is acoustically coupled to a first surface 7010 of transducer assembly 7000. In others In these respects, the 7006 plug can be a component of an ultrasonic waveguide.

[00111] The description now turns to techniques for acoustic coupling of ceramic piezoelectric elements to ultrasonic waveguides made of titanium or titanium alloys (ie Ti6Al4V) in D31 configurations. Advantages of D31 acoustic coupling techniques described here include low cost, low profile, ease of fabrication and assembly. Additional advantages include the ability to compress piezoelectric elements (especially in the coupled elongation direction) to provide greater efficiency and drive large loads. In a D31 acoustic train configuration, electrical contacts for electrical connection are provided on both sides of the ceramic piezoelectric elements. An electrical ground can be applied to the ultrasonic waveguide if there is electrical contact from the piezoelectric ceramic elements to the ultrasonic waveguide. In one aspect, low temperature acoustic coupling techniques are employed to minimize or prevent damage to ceramic piezoelectric elements (<150 °C). The electrical connections can also be used as a heat sink. Various techniques for acoustically coupling D31 element configurations to titanium/titanium alloy ultrasonic waveguides are described later in this document in conjunction with Figures 5 through 11.

[00112] Figure 5 is a perspective view of an ultrasonic surgical instrument 7100, in accordance with an aspect of this description. The 7100 Ultrasonic Surgical Instrument includes a 7118 Ultrasonic Transducer attached to a 7102 Ultrasonic Waveguide by a bonding material, wherein the 7100 Ultrasonic Surgical Instrument is configured to operate in a D31 mode. Figure 6 is a perspective view of a piezoelectric element 7104 for use with the 7100 ultrasonic surgical instrument shown in Figure 5, in accordance with an aspect of the present description. Ultrasonic transducer 7118 includes first and second piezoelectric elements 7104a, 7104b attached to opposite sides of ultrasonic waveguide 7102 by a bonding material. The 7104a-b piezoelectric elements may be PZT ceramic elements attached to a 7102 metal ultrasonic waveguide using a ceramic-to-metal bonding technique described later in this document.

[00113] Figure 7 is a cross-sectional view of the 7100 ultrasonic surgical instrument shown in Figure 5 in accordance with an aspect of the present description. The 7100 Ultrasonic Surgical Instrument includes an ultrasonic transducer attached to a 7102 ultrasonic waveguide by a bonding material, wherein the 7100 Ultrasonic Surgical Instrument is configured to operate in a D31 mode. The ultrasonic transducer includes a first piezoelectric ceramic element 7104a and a second piezoelectric ceramic element 7104b attached to opposite sides of the ultrasonic waveguide 7102 by a bonding material. Bonding material is used to attach the ceramic-to-metal connections to connect the ceramic piezoelectric elements 7104a, 7104b to the metal ultrasonic waveguide 7102. In the example illustrated in Figure 7, a lower surface of the upper piezoelectric element 7104a is attached to one side of the 7102 ultrasonic waveguide by a metal bonding material, such as a 7106a metal alloy solder. Similarly, a bottom surface of the bottom piezoelectric element 7104b is attached to the opposite side of the ultrasonic waveguide 7102 by a metal bonding material, such as a 7106b metal alloy solder. Alloy solder 7106a, 7106b can be used to bond ceramic piezoelectric elements 7104a, 7104b, which are made of a PZT material (i.e., )Pb[ZrxTi1-x]O3), to the metal ultrasonic waveguide 7102, which is made of titanium or titanium alloys (i.e., Ti6Al4V), without using the flux or pre-coating of the piezoelectric elements 7104a, 7104b. Metal alloy solder can be applied at temperatures below the Curie temperature of ceramics. Alloy 7106a, 7106b solder is thermally and electrically conductive, provides an airtight seal, and has high shear strength. Depending on the joining process, the 7106a, 7106b metal alloy solder can develop a chemical bond between the surfaces of the 7104a, 7104b piezoelectric elements and the 7102 ultrasonic waveguide.

[00114] Furthermore, a metal bonding material such as a metal alloy solder 7108a may also be used to bond a thin conductive metal element 7110a to a top surface of the top piezoelectric element 7104a. Similarly, a metal bonding material such as an alloy solder 7108b may be used to bond a thin conductive metal element 7110b to a top surface of the bottom piezoelectric element 7104b. The conductive metal elements 7110a, 7110b are suitable for making positive electrical connections through a brazed wire, crimp connection, or spade connection to the piezoelectric elements 7104a, 7104b. At temperatures below the Curie temperature of the piezoelectric elements 7104a, 7104b, bonding can be performed after biasing the piezoelectric elements, 7104a, 7104b. At temperatures equal to or greater than the Curie temperature of the piezoelectric elements 7104a, 7104b, the piezoelectric elements 7104a, 7104b can be biased after bonding the components of the ultrasonic surgical instrument 7100 as an assembly.

[00115] In one aspect, a metal bonding material such as a metal alloy solder 7106a, 7106b, 7108a, 7108b suitable for bonding ceramics to metal can be obtained from S-Bond Technologies, for example. Active metal alloy solders are useful for bonding ceramics to metal. Such solder alloys include active elements such as titanium and cerium added to SnAg, SnInAg and SnBi alloys to create a solder alloy that can be reacted directly with ceramic surfaces prior to bonding. Solder alloys produce reliable airtight joints with all metals, including steel, stainless steels, titanium, nickel alloys, copper and aluminum alloys, for example. Ceramics are generally not compatible with direct wetting processes (adhesion of molten metal layers) and ceramics and metals have widely different coefficients of thermal expansion (CTE). Solder alloys, by definition, melt and thus bond at temperatures below 840°F (448.89°C) and typically closer to 480°F (250°C). Thus, brazed joints are much better for joining ceramics to metals because the bond stresses are much lower due to solidification at much lower temperatures than brazed joints. With regard to conventional solders, the caveat remains that a layer of adherent metal first needs to be placed over the ceramic surface, followed then by a solder flux process to break up the oxides that form on the metal and coating. of metal onto ceramic as they are heated in the solder bonding process. The metal alloy solder known under the trade name S-BOND is an active solder suitable for joining metal alloys to ceramics by directly bonding the ceramic to the metal, forming joints without the use of flux and without pre-coating ceramic steps. This process eliminates multi-step coating processes and can be applied at temperatures below 400°F (204.44°C), preventing metal distortion and softening and preventing ceramic fracture. The gaskets produced are hermetic, passing < 10-9 atm-c3/s ductile and resistant SnAg or Snln-based alloys (> 34.47 MPa (5,000 psi) shear), and thermally conductive.

[00116] The geometric axis of polarization (P) of the piezoelectric elements 7104a, 7104b is indicated by the direction arrows 7114a, 7114b, respectively. The axis of motion of ultrasonic waveguide 7102 in response to excitation of piezoelectric elements 7104a, 7104b is shown by arrow of motion 7116 at the distal end of ultrasonic waveguide 7102 commonly referred to as the ultrasonic blade portion of the ultrasonic waveguide 7102. Motion axis 7116 is orthogonal to polarization axis (P) 7114a, 7114b.

[00117] Figures 8 to 11 illustrate cross-sectional views of exemplary metal alloy solder joints, 7106a, 7106b, 7108a, 7108b suitable for bonding ceramics to metal, as shown in Figure 7, in accordance with an aspect of this description. Two different processes can be used to bond ceramics to metal. A "mechanically activated" bonding process shown in Figures 8 and 9 can be performed at or near the melting temperature of metallic alloy solder (eg 250°C for S-Bond 220).

[00118] Figure 8 illustrates an example of an adhesive bond 7120 formed between a solder of metal alloy 7122 and a metal 7124 in accordance with an aspect of this disclosure. Bond 7120 can be produced by spreading, rubbing, or brushing the molten alloys over heated surfaces and "hot" mounting so that the alloy 7122 weld surfaces are agitated enough to break up the thin oxide skins that form while molten. As shown in Figure 8, atoms of Al, Cr, or Ti 7128 in metal 7124 and atoms of Ti or Ce 7130 in weld metal alloy 7122 form an adhesive bond at interface 7126.

[00119] Figure 9 illustrates an example of adhesive bonding 7140 between a ceramic 7142 (for example, PZT) and a metal 7144 (for example, titanium alloy steel) formed by a solder of metallic alloy 7146. The solder alloys Alloy 7146 alloys bond effectively, but joint strengths are nominally less than 20.68 MPa (3000 psi) shear. Such joints on 7142 ceramics and many 7144 metals are adhesive but not chemically bonded.

[00120] Figure 10 illustrates an example of a metallurgical/chemical bond 7150, in accordance with an aspect of this disclosure. Another 7154 metal alloy solder joining process employs a thermally activated process, which prepares the 7152 ceramic surfaces and develops a chemical bond with the surface through reactions of the active elements in the 7154 metal alloy solder. high temperature oven in a protective atmosphere furnace with the 7154 alloy solder placed over the 7152 ceramic surfaces to be joined. At elevated temperatures, the active elements in the 7154 metal alloy solder react with the 7152 ceramic to develop a chemical bond (e.g., Al(Ti)-Ag phases or Cu-Sn phases) at the 7156 interface between the 7152 ceramic and the solder Alloy 7154. A chemical bond and a layer of Alloy 7154 solder in a subsequent joining step provides a much higher level of joint strength and creates high performance ceramic metal joints that are better than most. of brazed sapphire and metal-to-ceramic joints made by the multi-step plating and MoMn processes.

[00121] Figure 11 is a microstructure illustration of a chemical bond 7160 of solder alloy 7162 and ceramic 7164 (e.g., PZT) in accordance with an aspect of this disclosure. A 7166 reaction zone is formed at the 7168 interface of 7164 ceramic solder to 7162 metal alloy. The S-Bond metal alloy solder provides high shear strengths in the joint. For example, using high temperature S-Bond alloy solder plating procedures, the shear strengths of the 7160 chemical bond at the 7168 interface can exceed 48.26 MPa (7,000 psi) and is resistant to thermal cycling of 50 to 150°C. S-Bond metal alloy solder is suitable for joining ceramic and metal surfaces without flux or plating and the process is much more tolerant of joint variations due to the high surface tension of the S-Bond metal alloy solder. The S-Bond metal alloy solder bonding process does not use chemical fluxes that need to be cleaned or that can etch metal components, leaving cosmetic defects.

[00122] In one aspect, the present description provides a method of acoustic coupling of ceramic piezoelectric elements (for example, PZT) to a metal ultrasonic waveguide (for example, titanium/titanium alloy) for use in a D31 configuration. The process further includes making electrical connections on both sides of both piezoelectric elements in the D31 acoustic train configuration. Generally speaking, the process includes soldering ceramic piezoelectric elements to a metal ultrasonic waveguide prior to biasing the piezoelectric elements and then biasing the assembly. Techniques for bonding ceramics to metal are described above in conjunction with Figures 8 through 11. In one aspect, the process includes attaching piezoelectric ceramic elements (eg, PZT) to a metal (eg, aluminum alloy) ultrasonic waveguide. titanium/titanium) through solder paste, reflow the solder paste to bond the piezoelectric elements to the ultrasonic waveguide, and polarize the piezoelectric elements as part of the piezoelectric element/ultrasonic waveguide assembly. An aspect of this process is described later in this document in conjunction with Figures 12A to 12C.

[00123] Figures 12A to 12C illustrate an ultrasonic surgical instrument 7200 that includes an ultrasonic waveguide 7202 attached to an ultrasonic transducer 7212 by a binding material, in which the ultrasonic surgical instrument 7100 is configured to operate in a D31 mode. Ultrasonic transducer 7212 includes first and second non-polarized piezoelectric elements 7204a, 7204b attached to opposite sides of ultrasonic waveguide 7202 by a bonding material. Figure 12A illustrates a 7200 ultrasonic surgical instrument prior to assembly and polarization in accordance with an aspect of this disclosure. The 7200 Ultrasonic Surgical Instrument includes a 7202 Metal Ultrasonic Waveguide (eg titanium/titanium alloy). A bonding material such as solder paste 7206 is applied to a surface of a first non-polarized piezoelectric element 7204a and a second non-polarized piezoelectric element 7204b. Solder Paste 7206 is a sticky mixture of flux and small solder particles and can be applied to the Piezoelectric Elements 7204a, 7204b with a stainless steel or nickel stencil using a screen printing process. Solder paste 7206 may also be applied to piezoelectric elements 7204a, 7204b by a jet printing mechanism, similar to an inkjet printer. After pasting, the piezoelectric elements 7204a, 7204b are advanced to a pick and place machine or a manual placement process to attach the piezoelectric elements 7204a, 7204b to the ultrasonic waveguide 7202.

[00124] Figure 12B illustrates the ultrasonic surgical instrument 7200 of Figure 12A before polarization with the first and second non-polarized piezoelectric elements 7204a, 7204b attached to the ultrasonic waveguide 7202 in a D31 configuration in accordance with an aspect of this description. After pasting, the piezoelectric elements 7204a, 7204b are attached to the ultrasonic waveguide 7202 using either a manual or automated process. An insulating gripper may be employed to clamp the first and second unbiased piezoelectric elements 7204a, 7204b before transporting, by reflow, the clamped piezoelectric elements 7204a, 7204b and ultrasonic waveguide assembly 7202 into a soldering oven. Once in the oven, the solder paste 7206 flows back to connect the first and second non-polarized piezoelectric elements 7204a, 7204b to the ultrasonic waveguide 7202.

[00125] Figure 12C illustrates the ultrasonic instrument 7200 of Figure 12B after reflow soldering and before polarizing the first and second non-polarized piezoelectric elements 7204a, 7204b attached to the ultrasonic waveguide 7202 in a D31 configuration according to an aspect of this description. As the trapped piezoelectric elements 7204a, 7204b and ultrasonic waveguide assembly 7202 are reflowed into a soldering oven, solder paste 7206 reflows to establish a bond between the first and second unbiased piezoelectric elements 7204a , 7204b and the 7202 ultrasonic waveguide. The 7206 solder paste is reflowable using standard surface mount technology. There are several techniques for reflowing 7206 solder. One technique employs infrared lamps and is called infrared reflow. Another technique employs hot gas convection using standard air or nitrogen gas. Another surface mount technology employs special fluorocarbon liquids with high boiling points that use a method called vapor phase reflow. Each method has its advantages and disadvantages.

[00126] After the first and second non-polarized piezoelectric elements 7204a, 7204b are attached to the ultrasonic waveguide 7202 using a reflow soldering technique, the entire ultrasonic instrument assembly 7200 is polarized. A polarization process can be performed in an oil bath with special fixture. The nature of the piezoelectric effect is closely related to the occurrence of electric dipole moments in solids. The latter can be induced by ions at crystal lattice sites with asymmetrically charged surroundings as in piezoelectric elements. The dipole density or polarization (dimensionality (C m/m3) can be calculated for crystals by summing the dipole moments per crystallographic unit cell volume. Since each dipole is a vector, the dipole density P is a vector field. Dipoles close to each other tend to be aligned in regions called Weiss domains. The domains are normally randomly oriented, but can be aligned using the process of polarization (not the same as magnetic polarization), a process by which a strong electric field is applied through the material, typically at elevated temperatures. Not all piezoelectric materials can be polarized. The polarization (P) axis of piezoelectric elements 7204a, 7204b is indicated by direction arrows 7208a, 7208b, respectively. motion of ultrasonic waveguide 7202 in response to excitation of piezoelectric elements 7204a, 7204b is shown by motion arrow 7210 at the distal end of ultrasonic waveguide 7202 generally referred to as the ultrasonic blade portion of ultrasonic waveguide 7202. motion axis 7210 is orthogonal to polarization (P) axis 7208a, 7208b.

[00127] The piezoelectric effect is the change of polarization P under the application of a mechanical stress. This can be caused by a reconfiguration of the dipole induction surroundings or by reorientation of molecular dipole moments under the influence of external voltage. Piezoelectricity can manifest itself in a variation in the intensity of polarization, its direction or both, with the details depending on: the orientation of P within the crystal; crystal symmetry; and applied mechanical stress. The change in P appears as a change in the surface charge density on the crystal faces, that is, as a change in the electric field extending between the faces caused by a change in the dipole density in the volume. For example, a 1 cm3 quartz cube with 2 kN (500 lbf) of correctly applied force can produce a voltage of 12,500 V.

[00128] Another technique for acoustic coupling of ceramic piezoelectric elements (for example, PZT) to a metal ultrasonic waveguide (for example, titanium/titanium alloy) for use in a D31 configuration is described later in this document together with Figures 13A to 13C. Figure 13A illustrates an ultrasonic surgical instrument 7300 that includes an ultrasonic transducer 7318 attached to an ultrasonic waveguide 7302 by a bonding material, wherein the ultrasonic surgical instrument 7300 is configured to operate in a D31 mode. As shown in Figure 13A, ultrasonic surgical instrument 7300 includes an ultrasonic waveguide 7302 configured to retain piezoelectric elements 7304a, 7304b in accordance with an aspect of this disclosure. The 7302 ultrasonic waveguide includes geometric features to retain the 7304a, 7304b piezoelectric elements. Ultrasonic waveguide 7302 includes a base portion 7320 and a first set of walls 7314a, 7316a extending from a side of base portion 7320 substantially perpendicular to the longitudinal axis LA. A second set of walls 7314b, 7316b extends from an opposite side of the base portion 7320 substantially perpendicular to the longitudinal axis LA. Protrusions 7306a, 7308a project from corresponding walls 7314a, 7316a along longitudinal axis LA. Protrusions 7306b, 7308b project from corresponding walls 7314b, 7316b along longitudinal axis LA. Protrusions 7306a, 7306b, 7308a, 7308b extend over a base portion 7320 of ultrasonic waveguide 7302 and are substantially parallel to base portion 7320. In one aspect, the first set of protrusions 7306a, 7306b and one side of the portion base 7320 define spaces 7310a, 7310b for receiving one end of piezoelectric elements 7304a, 7304b. The second set of projections 7308a, 7308b and an opposite side of the base portion 7320 define spaces 7312a, 7312b for receiving the other end of the piezoelectric elements 7304a, 7304b.

[00129] The ultrasonic transducer 7318 includes a first and a second piezoelectric element 7304a, 7304b attached to opposite sides of the base portion 7320 of the ultrasonic waveguide 7302 by a bonding material 7322a, 7322b such as a conductive epoxy, solder or alloy metal weld. The first piezoelectric element 7304a is slidably received in the first set of spaces 7310a, 7312a. The second piezoelectric element 7304b is slidably received in the second set of spaces 7310b, 7312b.

[00130] When the piezoelectric elements 7304a, 7304b are slidably received in the spaces 7310a, 7310b, 7312a, 7312b, the piezoelectric elements 7304a, 7304b can be attached to the base portion 7320 of the ultrasonic waveguide 7302 using a variety of bonding techniques and bonding materials described above in conjunction with Figures 8 to 11 or Figures 12A to 12C.

[00131] Figure 13B Illustrates an ultrasonic surgical instrument 7330 similar to the ultrasonic surgical instrument 7300 shown in Figure 13A, in which the protrusions 7306a, 7306b, 7308a, 7308b of the ultrasonic waveguide 7302 are inclined, or curved slightly, towards the base portion 7320 of ultrasonic waveguide 7302 for applying a clamping force of piezoelectric elements 7304a, 7304b against base portion 7320 of ultrasonic waveguide 7302. Protrusions 7306a, 7306b, 7308a, 7308b may be curved before or after piezoelectric elements 7304a, 7304b are slidably inserted into spaces 7310a, 7310b, 7312a, 7312b.

[00132] Figure 13C Illustrates an ultrasonic surgical instrument 7340 similar to the ultrasonic surgical instruments 7300, 7330 shown in Figures 13A and 13B, in accordance with an aspect of this description. As shown in Figure 13C, the piezoelectric elements 7304a, 7304b can be attached to the ultrasonic waveguide 7302 by a combination of an application of a bonding material, described in conjunction with Figure 13A, and a preparation of the protrusions 7306a, 7306b, 7308a, 7308b toward the base portion 7320 of the ultrasonic waveguide 7302 to apply a biasing force to the piezoelectric elements 7304a, 7304b as described in conjunction with Figure 13B.

[00133] In a conventional D33 ultrasonic transducer architecture, the piezoelectric elements (eg PZT plates) of an ultrasonic transducer are assembled in a previously compressed state to ensure that the piezoelectric elements do not operate in voltage mode. In a D31 architecture configuration, however, it may be desirable to have some precompression between each piezoelectric element and the ultrasonic waveguide. Figures 14 and 15 illustrate a technique for pre-compressing the piezoelectric elements during a binding phase of the piezoelectric elements to the ultrasonic waveguide, as discussed later in this document.

[00134] Figure 14 illustrates an ultrasonic surgical instrument 7400 that includes an ultrasonic transducer 7412 attached to an ultrasonic waveguide 7402 by a binding material, in which the ultrasonic instrument is configured to operate in a D31 mode according to an aspect of this description. Ultrasonic transducer 7412 includes first and second piezoelectric elements 7404a, 7404b. Figure 15 illustrates the ultrasonic surgical instrument 7400 shown in Figure 14 with a voltage V applied to piezoelectric elements 7404a, 7404b during an on phase in accordance with an aspect of this disclosure. As shown in Figure 14, the piezoelectric elements 7404a, 7404b are attached to the ultrasonic waveguide 7402 using a bonding material such as an epoxy adhesive 7406 to bond the piezoelectric elements 7404a, 7404b to the ultrasonic waveguide 7402. In one aspect , precompression of the piezoelectric elements 7404a, 7404b can be achieved by applying a voltage to the piezoelectric elements 7404a, 7404b while the epoxy 7406 is curing.

[00135] With reference now to Figures 14 and 15, consequently, in a D31 architecture configuration, the previous compression can be obtained between each piezoelectric element 7404a, 7404b and the ultrasonic waveguide 7402 by applying a voltage V to each element piezoelectric element 7404a, 7404b during the epoxy cure process 7406. A positive potential may be applied to electrical connections 7408a, 7408b formed at the free end of each piezoelectric element 7404a, 7404b and a ground potential may be applied to an electrical connection 7410 to the 7402 ultrasonic waveguide, for example. As shown in Figure 15, voltage V is applied to contract the piezoelectric elements 7404a, 7404b in the direction of the longitudinal axis LA of vibration as described in conjunction with Figure 2B, for example. The electrical connections between the ultrasonic waveguide 7402 and the fixed end of the piezoelectric elements 7404a, 7404b can be provided by a conductive epoxy 7406. The piezoelectric elements 7404a, 7404b can be attached to the ultrasonic waveguide 7402 using a variety of binding materials, such as the binding materials described in conjunction with Figures 8 to 11 or Figures 12A to 12C.

[00136] In other respects, in a D31 ultrasonic transducer architecture configuration, the present description provides a method for electrically connecting a power source to the D31 electrical contacts on either side of each piezoelectric element (eg PZT boards). Earthing can be done with the ultrasonic waveguide if there is electrical contact of the piezoelectric elements with the ultrasonic waveguide. In one aspect, the methods are run at low temperature to prevent or minimize damage to the piezoelectric elements (< 150 °C). The electrical connection can be used as a heat sink. These techniques are described below in conjunction with Figure 16.

[00137] Figure 16 illustrates an ultrasonic surgical instrument 7500 that includes an ultrasonic transducer 7510 attached to an ultrasonic waveguide 7502, by a binding material, in which the ultrasonic surgical instrument 7500 is configured to operate in a D31 mode according with an aspect of this description. Ultrasonic transducer 7510 includes piezoelectric elements 7506a, 7506b attached to opposite sides of ultrasonic waveguide 7502 by a bonding material. In one aspect, the bonding material is a conductive adhesive 7508. The conductive plates 7504a, 7504b are attached to the piezoelectric elements 7506a, 7506b, respectively, by a bonding material such as a conductive adhesive 7508, in accordance with an aspect of this disclosure. One method includes soldering the piezoelectric elements 7506a, 7506b on one side directly to the inside surfaces of the electrically conductive plates 7504a, 7504b (eg, copper plates or sheets) and on the other side of the ultrasonic waveguide 7502. A conductive epoxy 7508 is applied between the electrically conductive plates 7504a, 7504b and the free ends of the piezoelectric elements 7506a, 7506b. A conductive epoxy 7508 is also applied between the fixed ends of the piezoelectric elements 7506a, 7506b and the ultrasonic waveguide 7502. The electrically conductive elements, such as wires, can be connected to the electrically conductive plates 7504a, 7504b and the ultrasonic waveguide 7502 In one aspect, the ultrasonic waveguide 7502 can be formed by stamping and electrical connection features can be added to the ultrasonic waveguide 7502. The electrically conductive plates 7504a, 7504b can be formed from copper sheets and assembled into connectors- electrical female on a cable. Crimp connections can be stamped or formed into the 7502 ultrasonic waveguide and 7504a, 7504b electrically conductive plates (eg, copper sheets). Wire connections may be crimped during assembly. In many respects, the electrical connection process can include any of the above combinations.

[00138] Figures 17 and 18 illustrate an ultrasonic surgical instrument 7600 including an ultrasonic transducer 7624 attached to an ultrasonic waveguide 7602 by a binding material, in which the ultrasonic surgical instrument 7600 is configured to operate in a D31 mode. As shown in Figures 17 and 18, the ultrasonic surgical instrument 7600 includes a single midplane ultrasonic transducer 7624 acoustically coupled to an ultrasonic waveguide 7602 that includes a tuning fork-like structure 7606 in accordance with an aspect of the present disclosure. The 7602 ultrasonic waveguide and 7606 tuning fork-like structure are constructed from metal, such as titanium or titanium alloys, as described throughout this description. The tuning fork-like structure 7606 includes an upper yoke 7622a and a lower yoke 7622b defining a U-shaped opening 7608 therebetween for receiving the ultrasonic transducer 7624 therein. In one aspect, the tuning fork-like structure configuration 7606 limits the top and bottom sides of the 7624 ultrasonic transducer to couple more vibratory energy into the 7602 ultrasonic waveguide. The 7624 single mid-plane ultrasonic transducer includes a single 7612 piezoelectric element (e.g. PZT) and electrically conductive plates 7618a, 7618b attached to the top and bottom sides of the piezoelectric element 7612 by an electrically conductive bonding material such as a conductive epoxy, solder or metal solder alloy, for example. The upper yoke 7622a of the tuning fork-like structure 7606 defines an opening 7604 for providing access to an electrical connection to the electrically conductive top plate 7618a. Ultrasonic transducer 7624 is slidably inserted into the U-shaped opening 7608 in the direction of the arrow 7622 and then attached to the arrow as shown in Figure 18.

[00139] Figure 18 is a cross-sectional view of the ultrasonic surgical instrument 7600 shown in Figure 17 with the ultrasonic transducer 7624 inserted into the U-shaped opening 7608 defined by the tuning fork-like structure 7606 of the ultrasonic waveguide 7602 according to a aspect of this description. Prior to insertion of the ultrasonic transducer 7624 into the U-shaped opening 7608, a first bonding material, such as an electrically insulating adhesive 7614 (e.g., electrically insulating conductive epoxy), is applied to an inner surface 7610a of the upper yoke 7622a of the frame similar to the 7606 tuning fork or the 7618a electrically conductive top plate, or both. The 7614 electrically insulating adhesive electrically isolates the 7606 tuning fork-like structure and 7602 ultrasonic waveguide from the 7618a upper electrically conductive element. Furthermore, prior to insertion of the ultrasonic transducer 7624 into the U-shaped aperture 7608, a second bonding material such as an electrically conductive adhesive 7616 (e.g., electrically conductive epoxy) is applied to an inner surface 7610b of a lower yoke 7622b of the structure similar to tuning fork 7606 or lower electrically conductive plate 7618b or both. The 7616 Electrically Conductive Adhesive electrically couples the 7618b Electrically Conductive Bottom Plate to the 7606 Tuning Fork-like Structure and the 7602 Ultrasonic Waveguide.

[00140] When the ultrasonic transducer 7624 is inserted into the U-shaped opening 7608, the electrically insulating adhesive 7614 and the electrically conductive adhesive 7616 are cured to bond the ultrasonic transducer 7624 to the tuning fork-like structure 7606 of the ultrasonic waveguide 7602. One pole of a power source (eg, positive) is electrically connected to the electrically conductive top plate 7618a through opening 7604. Another pole of the power source (eg, negative or ground) is electrically connected to the ultrasonic waveguide 7602 and the tuning fork-like structure 7606 and the lower electrically conductive plate 7618b through the electrically conductive adhesive 7616. In general, the positive pole of the power source is connected to the electrically conductive upper plate 7618a and the negative pole of the power source or ground is connected to the 7602 ultrasonic waveguide or tuning fork-like structure 7606. However, configurations where the negative or ground pole of the power source is connected to the electrically conductive top plate 7618a and the positive pole of the power source is connected to the guide ultrasonic waveform 7602 or tuning fork-like structure 7606 are considered by this description.

[00141] In one aspect, the present description provides a D33 ultrasonic transducer configuration in which metal components are joined by a clamping process. The D33 piezoelectric elements are located in a tuning fork-like metal frame and compressed by a metal plug inserted at the proximal end of the frame. The metal plug is joined to the metal frame by a tamping process. Stamping is a forging process in which the dimensions of an item are changed using dies into which the item is forced. Tampering is generally a cold working process, but it can also be hot worked. An assembly fixture applies a compressive force during the tamping process to leave a compressed stress in the pile. The compression force can be measured by measuring the voltage of the piezo cell. Another configuration includes a U-frame with an opening provided at one distal end of the U-frame. Compression of the piezoelectric stack is achieved by inserting the horn/ultrasonic waveguide (eg, titanium or titanium alloy) into the opening and or pinching or threading of components while the piezo cell is under compression. The frame can be produced from a different material than the horn/ultrasonic waveguide, eg aluminium. These aspects are described later in this document in conjunction with Figures 19 to 21.

[00142] Figures 19A and 19B illustrate a D33 7700 ultrasonic transducer configuration in accordance with an aspect of this description. In Figure 19A, a tuning fork-like metal frame 7708 defining a U-shaped opening 7702 at a proximal end of metal frame 7708 is provided. The tuning fork-like metal structure 7708 is produced from a metal such as titanium or titanium alloy as described in the present invention. As shown in Figure 19B, a plurality of piezoelectric elements 7706a, 7706b, 7706c, 7706d are inserted into the U-shaped aperture 7702 to form a piezoelectric Langevin stack. A metal plug 7704 is inserted into the proximal end of the tuning fork-like metal frame 7708 until the plug 7704 contacts the piezo cell. A mounting fixture applies compressive forces FA1 from a distal end and a compressive force FA2 from a proximal end to compress the stack of piezoelectric elements 7706a to 7706d in housing 7708. A tamping force FS is applied to the metal plug 7704 to join the metal plug 7704 with the tuning fork-like metal structure 7708 to hold the stack of piezoelectric elements 7706a to 7706d under compression.

[00143] Figure 20 illustrates a D33 7800 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 7800 includes a U-shaped metal housing 7802 that defines a U-shaped aperture in which a plurality of piezoelectric elements 7804a, 7804b, 7804c, 7804d are positioned to form a Langevin stack. An ultrasonic waveguide/horn 7806 is inserted into a distal end of the U-shaped metal housing 7802 until the plug 7806 contacts the stack of piezoelectric elements 7804a to 7804d. A mounting fixture applies compressive forces FA1 from a distal end and a compressive force FA2 from a proximal end to compress piezoelectric elements 7804a through 7804d in metal housing 7802 (eg, aluminum). An FS clamping force is applied to the ultrasonic horn/waveguide 7806 to bond the ultrasonic horn/waveguide 7806 to the metal housing 7802 to hold the stack of piezoelectric elements 7804a to 7804d under compression.

[00144] Figure 21 illustrates a D33 7900 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 7900 includes a U-shaped metal housing 7902 defining a U-shaped opening for receiving a plurality of piezoelectric elements 7904a, 7904b, 7904c, 7904d in the form of a Langevin stack. The distal end of the 7902 U-shaped metal housing includes 7906 female threads and a 7910 ultrasonic horn/waveguide includes 7908 male threads. The 7910 ultrasonic horn/waveguide is threadably engaged to the metal housing at U-shape 7902. A mounting fixture applies compressive forces FA1 from a distal end and a compressive force FA2 from a proximal end to compress stack of piezoelectric elements 7904a to 7904d in housing 7902. An FT thread is applied to the 7910 Ultrasonic Horn/Waveguide to threadably join the 7910 Ultrasonic Horn/Waveguide to the 7902 enclosure while the stack of piezoelectric elements 7904a through 7904d is under compression.

[00145] Figures 22A to 22D illustrate a D33 10000 ultrasonic transducer configuration in accordance with an aspect of this disclosure. Ultrasonic transducer 10000 includes a U-shaped metal housing 10008 defining an opening 10002 at the proximal end thereof which is configured to receive a plurality of piezoelectric elements 10006a-d in the form of a Langevin cell. A plug 10004 is inserted into the proximal end of the U-shaped metal housing 10008 until it contacts the stack of piezoelectric elements 10006a-d. Plug 10004 can have a T-shaped configuration as shown in Figure 22A, rounded edges as shown in Figure 22B, an I-shaped configuration as shown in Figures 22B and 22C, a rectangular configuration as shown in Figure 22D, or any other suitable configuration. A mounting fixture applies compressive forces FA1 from a distal end and FA2 from a proximal end to compress stack of piezoelectric elements 10006a-d in compartment 10008. When a desired compressive force is achieved (measured, for example , by tensioning the stack of piezoelectric elements 10006a-d), a link 10010 is applied at the points of interaction between the plug 10004 and the housing 10008 while the stack of piezoelectric elements 10006a-d is under compression. The mounting fixture can maintain compressive forces FA1, FA2 until connection 10010 is strong enough to independently maintain the desired compressive force on the stack of piezoelectric elements 10006a-d. Connection 10010 may include, for example, an adhesive resin or complementary thread, as described above in relation to Figure 21. Connection 10010 may also be obtained through manufacturing processes, including, for example, soldering or brazing. If the process for establishing or fabricating bond 10010 requires a temperature high enough to produce depolarization in piezoelectric elements 10006a-d, then ultrasonic transducer 10000 may be polarized or repolarized after assembly.

[00146] Figure 23 illustrates a D33 10100 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10100 includes a U-shaped metal housing 10108 defining an aperture at the distal end thereof that is configured to receive a plurality of piezoelectric elements 10106a-d in the form of a Langevin cell. The proximal end 10103 of the ultrasonic waveguide 10102, which defines a plug, is inserted into the distal end of the U-shaped metal housing 10108 until it contacts the stack of piezoelectric elements 10106a-d. A mounting fixture applies compressive forces FA1 from a distal end and FA2 from a proximal end to compress stack of piezoelectric elements 10106a-d in housing 10108. When a desired compressive force is achieved (as measured, for example, by voltage of the stack of piezoelectric elements 10106a-d), a link 10104 is applied at the points of interaction between the ultrasonic waveguide 10102 and the housing 10108 while the stack of piezoelectric elements 10006a-d is under compression. The mounting fixture can maintain compressive forces FA1, FA2 until connection 10104 is strong enough to independently maintain the desired compressive force on stack of piezoelectric elements 10106a-d. Connection 10104 may include, for example, an adhesive resin or complementary thread, as described above in relation to Figure 21. Connection 10104 may also be obtained through manufacturing processes, including, for example, soldering or brazing. If the process for establishing or fabricating bond 10104 requires a temperature high enough to produce depolarization in piezoelectric elements 10106a-d, then ultrasonic transducer 10100 may be polarized or repolarized after assembly. Ultrasonic waveguide 10102 can be constructed from the same metal material as housing 10108 or a different metal material, for example aluminum.

[00147] Figures 24A to 22C illustrate an ultrasonic transducer configuration D31 10200 according to an aspect of this description. Ultrasonic transducer 10200 includes a housing 10202 constructed from a shape memory alloy, a transducer base plate 10208 (e.g., transducer mounting portion) disposed within housing 10202, and an ultrasonic waveguide 10206 that extends through a proximal opening 10210 of housing 10202. Transducer base plate 10208 comprises flat faces on opposite sides for receiving piezoelectric elements. The shape memory alloy from which the housing 10202 is constructed can include, for example, CuAlTi and NiTi alloys. In many respects, the shape memory alloy of pocket 10202 has a standard shape 10212 (that is, a shape that pocket 10202 returns to when heated) that is smaller than the working shape of pocket 10202 (that is, the format in which the compartment 10202 is used to start the assembly of the ultrasonic transducer 10200), as shown in Figure 24C. In one aspect, the standard shape 10212 of the pocket 10202 is smaller both axially and radially from the working shape of the pocket 10202. In alternative aspects, the standard shape 10212 can be smaller in any number of dimensions compared to the shape housing 10202. The dimensions of the standard form factor 10212 are calculated to match the desired final dimensions of the ultrasonic transducer 10200, all components of the ultrasonic transducer 10200 being operatively coupled. Housing 10202 can have a variety of shapes, such as a cylindrical shape.

[00148] The housing 10202 includes a plurality of slots 10204a, 10204b that are configured to receive piezoelectric elements therethrough. In the aspect shown, slots 10204a, 10204b are disposed longitudinally in housing 10202 and each slot 10204a, 10204b extends along one side of transducer baseplate 10208 within housing 10202. A piezoelectric element can be inserted through each. of slots 10204a, 10204b such that each piezoelectric element is positioned on an opposite side of the transducer base plate in a D31 configuration. In alternative aspects, the slots can vary in number and orientation so that piezoelectric elements can be placed in alternative configurations within housing 10202, such as a D33 configuration. When the piezoelectric elements are located within the slots 10204a, 10204b, the ultrasonic transducer 10200 is heated to a temperature that causes the shape memory alloy in the housing 10202 to return to the standard shape 10212 as shown in Figure 24C. As housing 10202 returns to its default shape 10212, it exerts an axial compressive force FA and a radial compressive force FR on the components therein. One effect of the FA, FR compression forces is that the piezoelectric elements are placed securely in contact with the transducer baseplate 10208 and held in place in a D31 configuration. The piezoelectric elements can subsequently be electrically excited to induce ultrasonic vibrations as described above. A second effect is that the FA, FR compression forces bond the ultrasonic waveguide 10206 to the transducer baseplate 10208 and firmly hold these components in place so that ultrasonic vibrations can be transmitted through the transducer baseplate 10208 to the 10206 ultrasonic waveguide. When assembled, this aspect of the D31 10200 ultrasonic transducer can be used in conjunction with, for example, a surgical instrument. If the process for heating the 10202 housing format memory alloy requires a temperature high enough to produce depolarization in the piezoelectric elements, then the 10200 ultrasonic transducer can be polarized or repolarized after assembly.

[00149] Figures 25A to 25C illustrate a D33 10300 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10300 includes a U-shaped metal housing 10308 defining an opening 10302 at the proximal end thereof that is configured to receive a plurality of piezoelectric elements 10306a-d in the form of a Langevin cell. A plug 10304a is inserted into the proximal end of the U-shaped metal housing 10308 until it contacts the stack of piezoelectric elements 10306a-d. As plug 10304a is inserted into housing 10308, thread 10312 disposed on plug 10304a engages complementary thread 10310 disposed on the interior surface of housing 10308, allowing plug 10304a to be securely tightened against stack of piezoelectric elements 10306a-d to exert a compressive force against it. When a desired compressive force is obtained (as measured, for example, by the voltage of the stack of piezoelectric elements 10306a-d), tightening of the plug 10304a can be stopped. When tightened, engaged thread 10310, 10312 will hold plug 10304a in position. The piezoelectric elements 10306a-d can be biased before mounting the 10300 ultrasonic transducer, or the 10300 ultrasonic transducer can be biased or repolarized after mounting.

[00150] Figure 25D illustrates a D33 10300 ultrasonic transducer configuration in accordance with an aspect of this description. In this regard, plug 10304b includes thread 10316 that engages with the complementary thread 10318 of a nut 10314. When nut 10314 is threadably engaged with plug 10304b, tightening nut 10304b causes plug 10304b to be directed toward the inside the housing 10308 and come into contact with the stack of piezoelectric elements 10306a-d, exerting a compressive force against it, as described above. In the aspect shown, the plug 10304b does not have a thread that engages the internal thread of the housing 10308. In an alternative aspect, the ultrasonic transducer 10300 may include a combination of nut 10314 that threadably engages the plug 10304b and the plug thread 10312 which engages with internal thread 13310 of housing 10308, as described above in connection with Figures 25A through 25C.

[00151] Figure 25E illustrates a D33 ultrasonic transducer configuration, in accordance with an aspect of this description. In this regard, ultrasonic transducer 10300 includes one or more fasteners 10322a, 10322b that are configured to extend through housing 10308 and engage plug 10304c to hold plug 10304c in position. Fasteners 10322a, 10322b may include, for example, screws that are configured to threadably engage plug 10304c. Fasteners 10322a, 10322b can be configured, for example, to extend longitudinally across the distal end of housing 10308 to the proximal end to engage plug 10304c. When fasteners 10322a, 10322b are engaged with plug 10304c, tightening fasteners 10322a, 10322b causes plug 10304c to come into contact with piezoelectric element stack 10306a-d and exert a compressive force against it, as described above. . In the aspect shown, plug 10304c does not have threads that engage with the internal thread of housing 10308. In an alternative aspect, ultrasonic transducer 10300 may include a combination of fasteners 10322a, 10322b engaging plug 10304c, and plug thread 10312 engaging with internal thread 13310 of housing 10308, as described above in connection with Figures 25A through 25C.

[00152] Figures 26A to 26D illustrate a D33 ultrasonic transducer configuration and a process of assembling the same according to an aspect of this description. Ultrasonic transducer 10400 includes a U-shaped metal housing 10408 that defines an opening 10402 at the proximal end thereof that is configured to receive a plurality of piezoelectric elements 10406a-d in the form of a Langevin cell. Housing 10408 further includes a channel 10410 extending longitudinally along each of the opposing surfaces defining opening 10402. A plug 10404 includes a pair of tabs 10412a, 10412b that are configured to slideably engage channels 10410 that extend along opposite inner sides of housing 10408. As shown in Figure 26D, plug 10404 is inserted into the proximal end of U-shaped metal housing 10408 along channels 10410 until it contacts with the piezoelectric element stack 10406a-d. As shown in Figure 26C, a mounting fixture then applies a compression force F1 to plug 10404 to compress stack of piezoelectric elements 10406a-d in housing 10008. When a desired compression force is achieved (measured, for example, by the tension of stack of piezoelectric elements 10406a-d), a second compressive force F2 is applied to housing 10408 while stack of piezoelectric elements 10406a-d is under compression, as shown in Figure 26D. Compression force F2 deforms channels 10410 (and the tabs 10412a, 10412b located therein), locking plug 10404 in place. The compression force F2 can be applied, for example, by a punch press. The piezoelectric elements 10406a-d can be biased before mounting the ultrasonic transducer 10400, or the ultrasonic transducer 10400 can be biased or repolarized after mounting.

[00153] Figure 27 illustrates a D31 10500 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10500 includes a U-shaped metal housing 10508 that defines an opening 10502 at the proximal end thereof that is configured to receive a transducer base plate 10504 (e.g., a transducer mounting portion) that comprises faces flat on opposite sides to receive the piezoelectric elements 10506a-b. The piezoelectric elements 10506a-b can be affixed to the transducer base plate 10504 through, for example, the epoxy layer 10518a-b. Transducer baseplate 10504 has a generally T-shaped configuration, including a longitudinal or axial portion 10512 terminating at a distal end 10514 and a transverse portion 10510 affixed to a proximal end of axial portion 10512. , piezoelectric elements 10506a-b and axial portion 10512 are sized so that they form an interference or pressure fit with interior surface (or interior surfaces) 10524 defining opening 10502 when transducer base plate 10504 is inserted into opening 10502. Interference fit compresses piezoelectric elements 10506a-b in an axial and/or radial direction. This pre-compression of the piezoelectric elements 10506a-b improves the performance of the ultrasonic transducer 10500. The housing 10508 further includes a slot 10516 that is configured to receive the distal end 10514 of the transducer baseplate 10504. In one aspect, the distal end 10514 and slot 10516 are configured to engage in a press fit or interference fit. In another aspect, distal end 10514 is attached to slot 10516 by means of an adhesive resin, fasteners, soldering, brazing, a physical strain joint, or other attachment method. When transducer baseplate 10504 is attached to housing 10508 in the manner described, ultrasonic vibrations generated by piezoelectric elements 10506a-b are transmitted through transducer baseplate 10504 to the ultrasonic waveguide. Cross sectional portion 10510 of transducer baseplate 10504 is configured to seal or plug opening 10502. In one aspect, one or more surfaces 10520a-b of cross sectional portion 10510 are attached to opposing surfaces 10522a-b of housing 10508 through a adhesive resin, fasteners, soldering, brazing, a physical strain joint, or other fastening method. The 10506a-b piezoelectric elements can be biased before mounting the 10500 ultrasonic transducer, or the 10500 ultrasonic transducer can be biased or repolarized after mounting.

[00154] Figure 28 illustrates a D31 10600 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10600 includes a metal housing 10608 that defines one or more recesses 10602 that are configured to receive a piezoelectric element 10606a-b therein. The dimensions of the recesses 10602 are equal to a close tolerance for the dimensions of the piezoelectric elements 10606a-b, such that the recesses 10602 hold the piezoelectric elements 10606a-b securely in place when the piezoelectric elements 10606a-b are inserted therein. In the aspect shown, the metal housing 10608 includes a first recess 10602 and a second recess (not shown) disposed on an opposite side of the first recess 10602. Each recess 10602 includes a plurality of cavities 10610 disposed along the sides thereof. Each cavity 10610 is sized and shaped to securely receive a corresponding tab 10604 disposed along the edges of the piezoelectric elements 10606a-b. Housing 10608 with recesses 10602 can be manufactured by, for example, metal injection molding.

[00155] As the dimensions of the recesses 10602 are substantially equal to the dimensions of the piezoelectric elements 10606a-b and the tabs 10604 extend beyond the perimeter of the piezoelectric elements 10606a-b, the piezoelectric elements 10606a-b cannot be inserted into the recesses 10602 under conditions standard. In one aspect of ultrasonic transducer assembly 10600, housing 10608 is heated to a temperature that causes the material from which housing 10608 is constructed to expand and/or become malleable. After compartment 10608 is heated to the proper temperature, piezoelectric elements 10606a-b are then inserted into recesses 10602 such that tabs 10604 each engage a corresponding cavity 10610. Assembled ultrasonic transducer 10600 is then cooled. In some respects, the 10600 ultrasonic transducer is further compressed as it cools. As ultrasonic transducer 10600 cools (and optionally undergoes external compression), recesses 10602 compress around piezoelectric elements 10606a-b therein, causing tabs 10604 to become trapped within cavities 10610 and thereby securing the piezoelectric elements 10606a-b in place. In aspects where housing 10608 is manufactured using metal injection molding, piezoelectric elements 10606a-b may be inserted into recesses 10602 before housing 10608 is sintered because housing 10608 shrinks during the sintering process. Alternatively, piezoelectric elements 10606a-b may be inserted into recesses 10602 after housing 10608 has been sintered, but prior to the hot isostatic pressure step in the metal injection molding process as housing 10608 shrinks during the melting step. hot isostatic pressure. In an alternative aspect, piezoelectric elements 10606a-b, instead of housing 10608, are heated to a temperature that renders piezoelectric elements 10606a-b capable of being inserted into recesses 10602. When heated piezoelectric elements 10606a-b are placed within from recesses 10602, ultrasonic transducer 10600 is then cooled as described above, with or without external compression. If the process for heating the 10600 ultrasonic transducer requires a temperature high enough to produce depolarization in the 10606a-b piezoelectric elements, then the 10600 ultrasonic transducer can be polarized or repolarized after assembly.

[00156] Figures 29A and 29B illustrate a D31 10700 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10700 includes a metal housing 10708 defining one or more apertures 10702 extending therethrough. In one aspect, opening 10702 are extruded through holes that extend through housing 10708. Opening 10702 is configured to receive a piezoelectric element 10706 therein. In the aspect shown, the ultrasonic transducer 10700 comprises a single aperture 10702; however, ultrasonic transducer 10700 may include any number of apertures 10702 and corresponding piezoelectric elements 10706. The dimensions of aperture 10702 are equal to a close tolerance to the dimensions of piezoelectric element 10706, such that aperture 10702 holds piezoelectric element 10706 in place. place when the piezoelectric elements 10706 are inserted therein. Housing 10708 with opening (or openings) 10702 can be manufactured by, for example, metal injection molding.

[00157] In one aspect of the ultrasonic transducer assembly 10700, the housing 10708 is heated to a temperature that causes the material from which the housing 10708 is constructed to expand and/or become malleable. After compartment 10708 is heated to the proper temperature, piezoelectric element 10706 is then inserted into opening 10702. Assembled ultrasonic transducer 10700 is then cooled. In some respects, the 10700 ultrasonic transducer is further compressed as it cools. As the ultrasonic transducer 10700 cools (and optionally undergoes external compression), the recesses 10702 compress around the piezoelectric element 10706 in it, securing the piezoelectric element 10706 in place due to frictional engagements between the surface of the piezoelectric element 10706 and the surface of opening 1702. In aspects where housing 10708 is manufactured using metal injection molding, piezoelectric element 10706 may be inserted into opening 10702 before housing 10708 is sintered because housing 10708 shrinks during the sintering process . Alternatively, the piezoelectric element 10706 can be inserted into the opening 10702 after the compartment 10708 has been sintered, but before the hot isostatic pressure step in the metal injection molding process when the compartment 10708 shrinks during the hot isostatic pressure step as well. In an alternative aspect, piezoelectric element 10706, rather than housing 10708, is heated to a temperature that renders piezoelectric element 10706 capable of being inserted into aperture 10702. When heated piezoelectric element 10706 is placed within aperture 10702, the process 10700 ultrasonic transducer mounting hardware is the same as the aforementioned aspect. If the process for heating the 10700 ultrasonic transducer requires a temperature high enough to produce depolarization in the 10706 piezoelectric elements, then the 10700 ultrasonic transducer can be polarized or repolarized after assembly.

[00158] Figures 30A to 30D illustrate the D31 10800 ultrasonic transducer configurations according to an aspect of this description. Ultrasonic transducer 10800 includes a transducer base plate 10802, a plurality of piezoelectric elements 1806a-b attached to opposing surfaces of the transducer base plate 10802 (e.g., a transducer mounting portion) in a D31 configuration, and a plate compression element 10808a-b attached to the outer surface of each of the piezoelectric elements 1806a-b. The various components of the 10800 ultrasonic transducer can be bonded together, for example, by an electrically conductive epoxy adhesive. 30A and 30B, the transducer base plate 10802, piezoelectric elements 1806a-b, and compression plates 10808a-b include a series of apertures that are configured to align with one another so that a fastener 10804 can be received therethrough when the components are clamped together. Fastener 10804 includes, for example, a screw having a complementary nut 10810. In an alternate aspect depicted in Figures 30C-30D, only compression plates 10808a-b include a series of openings that are configured to align with each other. another so that fasteners 10804a-b can be received therethrough when the components are fastened together. Such fasteners 10804a-b may similarly include, for example, screws having complementary nuts 10810a-b. Squeezing the fastener (or fasteners) 10804 applies additional compression force to the ultrasonic transducer 10800, which can improve the performance of the ultrasonic transducer 10800. In some respects, the compression plates 10808a-b are constructed from a metal material which can help dissipate heat from the 10800 ultrasonic transducer.

[00159] Figure 31 illustrates a D33 10900 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 10900 includes a metal housing 10908 that defines an open interior 10902 that is configured to receive a plurality of piezoelectric elements 10906a-d in the form of a Langevin cell. Ultrasonic transducer 10900 further includes a threaded plug or threaded rod 10904 that extends through a threaded opening 10912 disposed at the proximal end of housing 10908 into housing 10902. As threaded rod 10904 is tightened, distal end 10910 the same contacts the stack of piezoelectric elements 10906a-d and applies a compressive force to compress the stack of piezoelectric elements 10906a-d into housing 10908. When a desired compressive force is achieved, the threaded rod 10904 will be held in position specific tightness due to its engagement with the threaded opening 10912. The degree of compressive force applied by the threaded rod 10904 can be adjusted by loosening or tightening the threaded rod 10904 to adjust the frequency of the stack of piezoelectric elements 10906a-d, without the need for of disassembling the ultrasonic transducer 10900. In some aspects, the ultrasonic transducer 10900 can switch between operating frequencies according to the degree of compression force applied to the stack of piezoelectric elements 10906a d. When the 10900 Ultrasonic Transducer is used in conjunction with a surgical instrument, being able to switch between operating frequencies in the field can allow the 10900 Ultrasonic Transducer to adjust to tissue effects encountered by the surgical instrument or different types of end actuators.

[00160] Figures 32A and 32B illustrate D31 11000 ultrasonic transducer configurations that have multiple pairs of piezoelectric elements in accordance with an aspect of this disclosure. The ultrasonic transducer 11000 includes a first array of transducers 11002a disposed on a first face of the transducer base plate 11008 (e.g., a transducer mounting portion) and a second array of transducers 11002b disposed on a second face, which opposes to the first face of transducer base plate 11008. In the aspect depicted in Figure 32A, transducer arrays 11002a-b are arranged in a D31 configuration. Each of the transducer arrays 11002a-b includes a first piezoelectric element 11006a and a second piezoelectric element 11006b disposed adjacent to one another. In the aspect shown, the piezoelectric elements 11006a-b are disposed longitudinally with respect to the longitudinal axis of the transducer base plate 11008. In other aspects, the piezoelectric elements 11006a-b are disposed in other orientations, such as orthogonally with respect to the plate. of transducer base 10008. In some aspects, piezoelectric elements 11006a-b of opposing transducer arrays 11002a-b are arranged in correlated pairs. In other words, each of the piezoelectric elements 11006a-b of the first transducer array 10002a is aligned with a corresponding piezoelectric element of the second transducer array 11002b. In the aspect shown, the piezoelectric elements 11006a-b are rectangular in shape and the array of transducers 11002a is square in shape.

[00161] In the aspect shown in Figure 32B, the array of transducers 11002c includes a first piezoelectric element 11006c, a second piezoelectric element 11006d, a third piezoelectric element 11006e and a fourth piezoelectric element 11006f disposed adjacent to each other. In one aspect, piezoelectric elements 11006c-f are arranged symmetrically along both the x and y axes of the flat transducer array 11002c. In the aspect shown, piezoelectric elements 11006c-f are square in shape and transducer array 11002c is similarly square in shape.

[00162] In various aspects, the transducer arrays 11002a-c shown in Figures 32A and 32B can be used in combination or in place of one another or in other arrays of piezoelectric elements. The piezoelectric elements 11006a-f in the segmented transducer arrays 11002a-c can be individually driven, thereby enabling the transducer arrays 11002a-c to produce unbalanced vibrations. In previously discussed aspects where piezoelectric elements on opposite faces of transducer base plate 11008 are balanced relative to each other, non-longitudinal motion of the waveguide and/or end actuator is undesirable. However, segmented transducer arrays 11002a-c that can be selectively activated in an asymmetric or unbalanced manner can produce two desirable effects. First, if there is unwanted vibration or bending in the surgical system, then the segmented transducer arrays 11002a-c can be selectively activated to compensate for unwanted lateral vibrations and to return the system to producing stable longitudinal motion. Second, in some cases lateral or torsional movement of the end actuator is desired. Therefore, in such cases, the segmented transducer arrays 11002a-c can be selectively activated in an asymmetrical manner to induce the desired non-longitudinal movement in the end actuator. Activation of piezoelectric elements 11006a-f in transducer arrays 11002a-c can be controlled, for example, by controlling the amount of electrical current applied to individual piezoelectric elements 11006a-f.

[00163] Figures 33A to 33C illustrate D31 ultrasonic transducer configurations 11100, 11200, 11300 having asymmetrically excitable piezoelectric transducer configurations 11102, 11202, 11302 in accordance with an aspect of this disclosure. As discussed above in relation to Figures 32A and 32B, it may be advantageous for ultrasonic transducers to be able to produce unbalanced or asymmetric vibrations in certain cases, such as to counteract unwanted non-longitudinal vibrations within the surgical system or to intentionally induce non-longitudinal movement. on the end actuator. In some aspects, the asymmetry can be obtained by the asymmetrical arrangement of the piezoelectric elements in relation to the longitudinal geometric axis of the ultrasonic waveguide. In other respects, asymmetry can be achieved by arranging the piezoelectric elements symmetrically with respect to the longitudinal axis of the ultrasonic waveguide, but selectively activatable in an asymmetrical manner. In aspects where ultrasonic transducers are capable of generating both symmetrical and asymmetrical vibrations depending on selective activation of the piezoelectric elements comprising the transducer array, surgical systems incorporating ultrasonic transducers can be configured to switch interchangeably between modes of symmetric and asymmetric activation by reversibly activating (i.e., electrically exciting) or deactivating the individual piezoelectric elements.

[00164] Figure 33A illustrates a configuration of the D31 ultrasonic transducer 11100 that includes a transducer base plate 11108 (for example, a transducer mounting portion) comprising flat faces on opposite sides to receive piezoelectric elements 11106a-c therein . The piezoelectric elements 11106a-c are dimensioned, shaped and arranged asymmetrically about the longitudinal axis of the waveguide 11104. The first piezoelectric element 11106a and the third piezoelectric element 11106c are approximately triangular in shape and the second piezoelectric element 11106b is irregularly shaped . In this regard, the first piezoelectric element 11106a and the second piezoelectric element 11106b are configured to generate a symmetrical vibration about the longitudinal axis of the waveguide 11104. Similarly, the first piezoelectric element 11106a and the third piezoelectric element 11106c are configured to generate a symmetrical vibration about the longitudinal axis of the waveguide 11104. However, activation of all three piezoelectric elements 11106a-c or activation of the second piezoelectric element 11106b and the third piezoelectric element 11106c is configured to generate an asymmetric vibration due to the sizes, shapes and arrangements of the piezoelectric elements 11106a-c.

[00165] Figure 33B illustrates a configuration of the D31 ultrasonic transducer 11200 that includes a transducer base plate 11208 (for example, a transducer mounting portion) comprising flat faces on opposite sides to receive piezoelectric elements 11206a-c therein . Piezoelectric elements 11206a-c are sized, shaped, and arranged symmetrically about the longitudinal axis of waveguide 11204, but can be selectively activated to generate asymmetric vibrations. Specifically, activation of all three piezoelectric elements 11206a-c or activation of the first piezoelectric element 11206a and the third piezoelectric element 11206c are configured to generate symmetrical vibrations. On the other hand, activation of the second piezoelectric element 11206b and one of the first piezoelectric element 11206a or the third piezoelectric element 11206c is configured to generate asymmetric vibrations.

[00166] Figure 33C illustrates a configuration of the D31 ultrasonic transducer 11300 that includes a transducer base plate 11308 (for example, a transducer mounting portion) comprising flat faces on opposite sides to receive piezoelectric elements 11306a-c therein . The piezoelectric elements 11306a-c are sized and shaped equivalent to each other, but are arranged asymmetrically about the longitudinal axis of the waveguide 11304. The activation of the first piezoelectric element 11306a and the second piezoelectric element 11306b is configured to generate vibrations symmetrical; however, activation of any other combination of piezoelectric elements 11306a-c is configured to generate asymmetric vibrations.

[00167] It should be noted that Figures 32A to 33C are merely exemplary and a variety of other configurations of segmented ultrasonic transducer arrays configured to generate symmetrical vibrations, asymmetrical vibrations or a combination of symmetrical vibrations or asymmetrical vibrations are considered. Furthermore, descriptions of various aspects of ultrasonic transducer arrays incorporating 2, 3, and 4 piezoelectric elements are illustrative only. The teachings of the present invention are similarly applicable to ultrasonic transducer arrays incorporating more than 4 piezoelectric elements. Yet still, in many respects, the piezoelectric elements of ultrasonic transducer arrays can be activated synchronously, asynchronously, or with a variety of ultrasonic activation signals that may differ in frequency, phase, or amplitude.

[00168] Figures 34A and 34B illustrate a D31 ultrasonic transducer configuration 11400, in which the piezoelectric elements 11406a-b are displaced relative to each other according to an aspect of this description. The ultrasonic transducer 11400 includes a transducer base plate 11408 (e.g., a transducer mounting portion), a first piezoelectric element 11406a disposed on a first face of the transducer base plate 11408, and a second piezoelectric element 11406b disposed on a second face opposite the first face. The first piezoelectric element 11406a and the second piezoelectric element 11406b are longitudinally displaced relative to each other. In one aspect, each of the piezoelectric elements 11406a-b are positioned at an acoustic array node on the transducer base plate 11408. A node is a minimum or zero pass in the standing wave of vibratory motion (i.e., where motion is generally minimal). Therefore, the piezoelectric elements 11406a-b are displaced from each other by a distance equal to half the wavelength (A/2) of the acoustic array.

[00169] In aspects of ultrasonic transducers that incorporate piezoelectric elements that are arranged in an aligned manner (that is, are not offset from each other) on the transducer base plate 11408, the ultrasonic transducers generate semiwaves. On the other hand, arranging the piezoelectric elements 11406a-b so that they are displaced by half the wavelength (À/2) of the acoustic array causes the ultrasonic transducer 11400 to generate a full wave. A full-wave vibratory motion can be used to introduce non-longitudinal motion into an end actuator driven by the acoustic assembly. Ultrasonic transducer 11400 may further incorporate one or more balancing features configured to balance or compensate for bending motion or bending mode induced by the full wave generated by displaced piezoelectric elements 11406a-b. If additional balancing features are used to compensate for the offset piezoelectric elements 11406a-b, ultrasonic transducer 11400 induces longitudinal motion in the end actuator, as depicted in Figure 34C. If balancing features are not used to compensate for piezoelectric elements 11406a-b, ultrasonic transducer 11400 induces non-longitudinal or flexural movement in the end actuator, as depicted in Figure 34D. In some aspects, the balance features can be selectively activated, allowing a surgical instrument incorporating the 11400 ultrasonic transducer to switch between longitudinal and non-longitudinal modes for the end actuator.

[00170] It should be noted that the teachings of any aspect of an ultrasonic transducer assembly represented as a specific transducer architecture, for example, a D31 transducer architecture or a D33 transducer architecture, are equally applicable to ultrasonic transducers that use other configurations, unless otherwise specified or unless such teaching conflicts with the structure of the specific transducer architecture. For example, the teachings of an aspect of an ultrasonic transducer assembly depicted as a transducer architecture D31, as in Figures 19A to 23, 25A to 26D and 31 are similarly applicable to a transducer assembly D33, as in Figures 24A to C, 27 to 30D, and 32A to 34B, and vice versa (unless conflicting with the structure of the specific transducer architecture).

[00171] Figures 35A to 35E illustrate various views of a surgical tool 11500 including a waveguide 11508 of a surgical instrument having complex features and a process for manufacturing the same in accordance with an aspect of this description. Surgical tool 11500 comprises a proximal transducer baseplate 11506 (e.g., a transducer mounting portion), a distal end actuator 11502, and a longitudinal portion or waveguide 11508 extending therebetween. In various aspects, waveguide 11508 further comprises a plurality of teeth 11504 disposed along its length. Furthermore, in various aspects, waveguide 11508 is twisted so that teeth 11504 extend from the longitudinal axis of waveguide 11508 at a variety of different angles, as shown in Figure 35E.

[00172] To manufacture the surgical instrument 11500, the first step is to manufacture a flat plate surgical tool 11500 comprising a plurality of teeth 11504, as shown in figures 35B and 35D. Surgical tool 11500 can be manufactured through a variety of manufacturing processes including, for example, metal injection molding. The teeth 11504 can be formed on the surgical instrument 11500 through the metal injection molding process or through, for example, forming, machining, cutting, forging, grinding, polishing, deburring, turning, or any other manufacturing process. Then, the waveguide 11508 is gradually twisted, as shown in Figure 35C. Waveguide 11508 can be twisted through a variety of fabrication processes including, for example, passing waveguide 11508 through a series of progressive dies. Twist can also be used to adjust various features of the 11508 waveguide, such as curvature, offset, flex section, and thin or tapered tissue gripping sections. The 11508 waveguide can be twisted at any point along its length. In one aspect, the waveguide is twisted such that teeth 11504 are symmetrically offset from one another (i.e., adjacent teeth 11504 are angularly separated by a fixed amount). In this regard, the angularly symmetrical teeth 11504 generate both longitudinal and torsional (i.e., non-longitudinal) movement in end actuator 11502.

[00173] Figures 36A to 36D illustrate various views of an ultrasonic transducer configuration D31 11600 configured to generate non-longitudinal movement and components thereof according to an aspect of this description. Ultrasonic transducer 11600 includes a metal housing 11608 that includes a recess 11602 configured to receive a cylindrical piezoelectric element 11604 therein. Ultrasonic transducer 11600 further comprises a cylindrical transducer holder 11610 configured to support cylindrical element 11604 thereon and a plurality of electrodes 11612a-c disposed around piezoelectric element 11604. In one aspect, electrodes 11612a-c are angularly displaced each other by a fixed amount (ie, the angularly symmetrical electrodes 11612a-c). Piezoelectric element 11604 may be affixed to transducer support 11610 by, for example, a conductive epoxy. Transducer holder 11610 may be affixed to the interior side walls of recess 11602, thereby supporting piezoelectric element 11604 and electrodes 11612a-c within the recess. In various respects, each of electrodes 11612a-c is asymmetrical or unbalanced about at least the geometric axis (i.e., x, y, or z), thereby causing each of electrodes 11612a-c to have a displacement of liquid mass. When ultrasonic transducer 11600 is in use, angularly offset electrodes 11612a-c that are asymmetrically weighted cause ultrasonic transducer 11600 to induce both longitudinal and torsional (i.e., non-longitudinal) motion in the end actuator of the surgical instrument. .

[00174] Figure 37 illustrates a perspective view of an electrical connector 11700 for an ultrasonic signal generator for a surgical instrument according to an aspect of this description. Various surgical instruments, such as those disclosed in U.S. Patent Application, Attorney's Document No. END7917USNP5/160045-5 entitled "TISSUE LOADING OF A SURGICAL INSTRUMENT," which is incorporated herein by reference in its entirety, include an electrical connector 11700 that it is connectable to an ultrasonic signal generator to drive the piezoelectric elements. Electrical connector 11700 includes a first wire 11706a and a second wire 11706b disposed on an inner side 11704 that is configured to be enclosed within the surgical instrument housing, and a first pin 11708a and a second pin 11708b disposed on an outer side 11704 that are configured to be connected to an ultrasonic signal generator. The first wire 11706a and the second wire 11706b are electrically connected to the piezoelectric elements of the ultrasonic transducer and transmit the signal generated by the ultrasonic signal generator thereto.

[00175] The inner side 11704 of the electrical connector 1700 is intended to be sealed against the surrounding environment to prevent the entry of moisture, microbes and other contaminants that may damage the function of the surgical instrument or otherwise pose safety risks to operators and/or patients. If contaminants enter the surgical instrument compartment, it may be desirable for the surgical instrument to generate an alarm or alert, cease operation, or take some other action to notify instrument operators that an error has occurred. In that regard, the electrical connector 11700 comprises a first conductive path 11712a and a second conductive path 11712b extending along the inner side 11704 of the electrical connector 11700 of the first wire 11706a and the second wire 11706b, respectively. Conductive paths 11712a-b may include, for example, soldered channels. Conductive paths 11712a-b extend toward each other, but terminate such that they are separated by a gap that is large enough to avoid the arc between them, but small enough that a relatively small amount of water can pass through them. fill the gap. In one aspect, the gap between the conductive paths 11712a-b is filled with a hydrophilic coating 11714, as depicted in Figure 37. In another aspect, the geometry of the electrical connector 11700 is configured to channel fluid into the gap between the conductive paths 11712a-b (for example, inner side 11704 is constructed as a curved surface with a local or global minimum located across the span). In either aspect, if fluid enters the surgical instrument compartment, it is funneled or drawn into the gap between conductive paths 11712a-b. When fluid hits the gap, it causes a short in the electrical system. In one aspect, the short circuit causes the surgical instrument to stop working. Therefore, the surgical instrument is prevented from being used if its internal compartment is contaminated with moisture. In another aspect, the short causes the surgical instrument circuit to generate an error signal, which in turn can be detected and cause an alert or alarm to be generated.

[00176] Figures 38 to 41 illustrate various views of a D33 11800 ultrasonic transducer configuration in accordance with an aspect of this description. Ultrasonic transducer 11800 includes a metal housing 11808 defining an open interior 11802 that is configured to receive a plurality of piezoelectric elements 11806a-f in the form of a Langevin cell. Housing 11816 includes a connector 11816 that is configured to receive an ultrasonic waveguide. Ultrasonic transducer 11800 further includes a threaded plug or threaded rod 11804 extending through a threaded opening 11814 disposed at the proximal end of housing 11808 within housing 11802. Ultrasonic transducer 11800 further includes a plate 11812 located between the stack of elements piezoelectric elements 11806a-f and the distal end 11810 of the threaded rod 11804. As the threaded rod 11804 is tightened, the distal end 11810 thereof contacts the plate 11812 and applies a compression force to compress the stack of piezoelectric elements 11806a- f in slot 11808. In many respects, the 11812 card is constructed from an electrically conductive material.

[00177] When a desired compressive force is obtained, the threaded rod 11804 will be kept in the specific tight position due to its engagement with the threaded opening 11814. The degree of compression force applied by the threaded rod 11804 can be adjusted by loosening or tightening of the threaded rod 11804 to adjust the frequency of the stack of piezoelectric elements 11806a-f, without the need to disassemble the ultrasonic transducer 11800. In some respects, the ultrasonic transducer 11800 can switch between operating frequencies according to the degree of compression force applied in the stack of piezoelectric elements 11806a-d. When the 11800 Ultrasonic Transducer is used in conjunction with a surgical instrument, being able to switch between operating frequencies in the field can allow the 11800 Ultrasonic Transducer to adjust to tissue effects encountered by the surgical instrument or different types of end actuators.

[00178] The ultrasonic transducer 11800 further includes a first wire 11818 and a second wire 11820 that are electrically coupled to the stack of piezoelectric elements 11806a-f. First wire 11818 can be used to provide a first electrical potential and second wire 11820 can be used to provide a second electrical potential. In one aspect, the first electric potential is positive and the second electric potential is ground or negative. In one aspect, the connection points 11822a-c of the first wire 11818 and the connection points 11824a-d of the second wire 11820 are attached to the junctions between the board 11812 and each of the piezoelectric elements 11806a-f, which may be connected, for example, by a conductive adhesive. The connection points 11822a-c of the first wire 11818 and the connection points 11824a-d of the second wire 11820 can be arranged so that they alternate with each other. In one aspect, the connection points 11824a-d of the second wire 11820, representing the negative or ground connection, may be located at the outer connection points 11824a, 11824d of the stack of piezoelectric elements 11806a-f.

[00179] The devices described here can be designed so that they are discarded after a single use, or can be designed so that they are used multiple times. In either case, however, the device can be refurbished for reuse after at least one use. Reconditioning can include any combination of the steps of disassembling the device, followed by cleaning or replacing specific parts and subsequent reassembly. In particular, the device can be disassembled and any number of parts or specific parts of the device can be selectively replaced or removed, in any combination. By cleaning and/or replacing specific parts, the device can be reassembled for subsequent use in the refurbishment facility or by a surgical team immediately prior to a surgical procedure. Those skilled in the art will understand that refurbishing a device can use a variety of techniques to disassemble, clean/replace, and reassemble. Use of these techniques, as well as the resulting refurbished device, are all within the scope of this application.

[00180] Although several aspects have been described here, many modifications and variations of those aspects can be implemented. For example, different types of end actuators can be employed. In addition, where materials are disclosed for certain components, other materials may be used. The aforementioned description and the following claims are intended to cover all such modifications and variations.

[00181] Any patent, publication or other descriptive material, in whole or in part, which is incorporated by way of reference to the present invention, is incorporated into the present invention only to the extent that the incorporated materials do not conflict with existing definitions, statements or other description material presented in this description. Accordingly, and to the extent necessary, the description as explicitly set forth herein supersedes any conflicting material incorporated into the present invention by way of reference. Any material, or portion thereof, incorporated herein by reference but which conflicts with existing definitions, statements, or other descriptive materials presented herein, is incorporated herein only to the extent that there is no conflict between the material incorporated and existing descriptive material.

[00182] Various aspects of the subject described here are exposed in the following numbered examples:

[00183] Example 1. Compressed ultrasonic transducer assembly comprising: a metal housing defining an opening; at least two piezoelectric elements disposed within the aperture and compressed by a compressive force, wherein the at least two piezoelectric elements are configured to operate in a D33 mode; and a metal plug attached to the metal housing to close the opening and to maintain the at least two piezoelectric elements in a compressed state within the metal housing.

[00184] Example 2. Compressed ultrasonic transducer assembly, according to Example 1, which further comprises a welded joint to join the metal plug to the metal housing.

[00185] Example 3. Compressed ultrasonic transducer assembly, according to Example 1 or Example 2, which further comprises an epoxy gasket to join the metal plug to the metal housing.

[00186] Example 4. Compressed ultrasonic transducer assembly, according to one or more of Example 1 to Example 3, in which the metal housing and the metal plug each comprise a threaded end and the metal housing and the plug of metal are threaded together.

[00187] Example 5. Compressed ultrasonic transducer assembly, according to one or more of Example 1 to Example 4, which further comprises a pressed joint for joining the metal plug to the metal housing.

[00188] Example 6. Compressed ultrasonic transducer assembly, according to one or more of Example 1 to Example 5, in which the metal housing has a fork-like metal structure.

[00189] Example 7. Ultrasonic surgical instrument comprising: an ultrasonic waveguide; an ultrasonic transducer mounted to the ultrasonic waveguide and configured to operate in a D31 mode, the ultrasonic transducer comprising: a first piezoelectric ceramic element having a first side attached to a first side of the ultrasonic waveguide by a first bonding material; and a second piezoelectric ceramic element having a first side attached to a second side of the ultrasonic waveguide by the first bonding material, wherein the first side of the ultrasonic waveguide is opposite the second side of the ultrasonic waveguide.

[00190] Example 8. Ultrasonic surgical instrument, according to Example 7, further comprising: a first electrically conductive plate attached to a second side of the first ceramic piezoelectric element by a second bonding material; and a second electrically conductive plate attached to a second side of the second piezoelectric ceramic element by the second bonding material.

[00191] Example 9. Ultrasonic surgical instrument, according to Example 7 or Example 8, where the first bonding material is the same as the second bonding material.

[00192] Example 10. Ultrasonic surgical instrument according to one or more of Example 8 to Example 9, wherein the first bonding material is a solder bonding material and the second bonding material is a solder bonding material conductive epoxy.

[00193] Example 11. Ultrasonic surgical instrument according to one or more of Example 8 to Example 10, wherein the solder is a metal solder alloy bonding material.

[00194] Example 12. Ultrasonic surgical instrument according to one or more of Example 7 to Example 11, wherein the first bonding material is a solder bonding material.

[00195] Example 13. Ultrasonic surgical instrument according to Example 12, wherein the solder material is a metal solder alloy bonding material.

[00196] Example 14. Ultrasonic surgical instrument, according to one or more of Example 7 to Example 13, in which the first ceramic piezoelectric element has a geometric axis of polarization in a direction from the first side to the second side of the first ceramic piezoelectric element and the second ceramic piezoelectric element have a bias axis in a direction from the first side to the second side of the second ceramic piezoelectric element to operate in a D31 mode.

[00197] Example 15. Ultrasonic surgical instrument, according to Example 14, in which a geometric axis of movement of the ultrasonic waveguide is orthogonal to the geometric axes of polarization of the first and second ceramic piezoelectric elements.

[00198] Example 16. Ultrasonic surgical instrument, according to one or more of Example 14 to Example 15, in which the first and second piezoelectric elements are non-polarized before connection to the respective first and second sides of the ultrasonic waveguide and are polarized after the first and second piezoelectric elements are connected to the respective first and second sides of the ultrasonic waveguide.

[00199] Example 17. Ultrasonic surgical instrument comprising: an ultrasonic waveguide comprising: a base portion; first and second walls extending from one side of the base portion; and first and second projections projecting from corresponding first and second walls, a first space being defined between the first projection and the base portion and a second space being defined between the second projection and the base portion base; and an ultrasonic transducer attached to the ultrasonic waveguide, the ultrasonic transducer comprising at least one piezoelectric element slidably disposed between and attached to the first and second spaces.

[00200] Example 18. Ultrasonic surgical instrument, according to Example 17, in which the at least one piezoelectric element is attached to the base portion of the ultrasonic waveguide by a binding material.

[00201] Example 19. Ultrasonic surgical instrument, according to Example 17 or Example 18, in which the first and second projections are inclined towards the base portion of the ultrasonic waveguide to fix the at least one piezoelectric element to the base portion of the ultrasonic waveguide.

[00202] Example 20. Ultrasonic surgical instrument, according to one or more of Example 17 to Example 19, in which the at least one piezoelectric element is attached to the base portion of the ultrasonic waveguide by a bonding material, and wherein the first and second protrusions are angled towards the base portion of the ultrasonic waveguide to secure the at least one piezoelectric element to the base portion of the ultrasonic waveguide in combination with the bonding material.

[00203] Example 21. Ultrasonic surgical instrument, according to one or more of Example 17 to Example 20, in which the ultrasonic waveguide further comprises a third and a fourth wall extending from an opposite side of the portion base; third and fourth projections projecting from corresponding third and fourth walls, a third space being defined between the third projection and the base portion and a fourth space being defined between the fourth projection and the base portion.

[00204] Example 22. Ultrasonic surgical instrument, according to Example 21, in which the ultrasonic transducer further comprises a second piezoelectric element disposed in a sliding manner between the third and fourth spaces and fixed thereto.

[00205] Example 23. Ultrasonic surgical instrument, according to Example 22, in which the second piezoelectric element is attached to the base portion of the ultrasonic waveguide by a binding material.

[00206] Example 24. Ultrasonic surgical instrument, according to one or more of Example 22 to Example 23, in which the third and fourth projections are inclined towards the base portion of the ultrasonic waveguide to fix the second element piezoelectric to the base portion of the ultrasonic waveguide.

[00207] Example 25. Ultrasonic surgical instrument, according to one or more of Example 22 to Example 24, in which the second piezoelectric element is attached to the base portion of the ultrasonic waveguide by a bonding material, and wherein the third and fourth protrusions are angled towards the base portion of the ultrasonic waveguide to secure the second piezoelectric element to the base portion of the ultrasonic waveguide in combination with the binding material.

[00208] Example 26. Ultrasonic surgical instrument comprising: an ultrasonic waveguide; and an ultrasonic transducer attached to the ultrasonic waveguide; the ultrasonic waveguide comprising a tuning fork-like structure comprising: an upper yoke; and a lower yoke defining a U-shaped opening therebetween configured to receive the ultrasonic transducer therein.

[00209] Example 27. Ultrasonic instrument, according to Example 26, in which the upper fork of the tuning fork-like structure defines an opening to provide access for an electrical connection to the ultrasonic transducer.

[00210] Example 28. Ultrasonic instrument, according to Example 26 or Example 27, wherein the ultrasonic transducer comprises: a piezoelectric element; a first electrically conductive plate attached to a top side of the piezoelectric element by an electrically conductive bonding material; and a second electrically conductive plate attached to a top and bottom side of the piezoelectric element by an electrically conductive bonding material.

[00211] Example 29. Ultrasonic instrument, according to Example 28, further comprising: an electrically insulating bonding material disposed between the first electrically conductive plate and an inner surface of the upper fork; and an electrically conductive bonding material disposed between the second electrically conductive plate and an inner surface of the lower yoke.

Claims (10)

1. An ultrasonic transducer assembly comprising: a metal waveguide (7102) comprising a first flat side and a second flat side opposite the first flat side; a first ceramic piezoelectric element (7104a) and a second ceramic piezoelectric element (7104b), the first ceramic piezoelectric element (7104a) fixed to the metal waveguide (7102) on the first flat side by a first bonding material (7106a) ,b) and the second ceramic piezoelectric element (7104b) fixed to the metal waveguide (7102) on the second flat side by the first bonding material (7106a,b); characterized in that the first and second ceramic piezoelectric elements are configured to operate in a D31 mode; wherein the first piezoelectric ceramic element (7104a) has a bias axis in a direction from the first flat side of the metallic waveguide (7102) to one side of the first piezoelectric ceramic element (7104a) opposite the first flat side , and the second piezoelectric ceramic element (7104b) has a bias axis in a direction from the second flat side to a side of the second piezoelectric ceramic element (7104b) opposite the second flat side, for operating in the D31 mode; and wherein the ultrasonic transducer assembly is manufactured such that the first and second piezoelectric ceramic elements are depolarized prior to attachment to the respective first and second sides of the metallic waveguide (7102) and are polarized after the first and second ceramic piezoelectric elements are attached to respective first and second sides of the metal waveguide (7102). 2. Ultrasonic surgical instrument according to claim 1, characterized in that it further comprises: a first electrically conductive plate (7110a) attached to a second side of the first piezoelectric ceramic element (7104a) by a second bonding material; and a second electrically conductive plate (7110b) secured to a second side of the second piezoelectric ceramic element (7104b) by the second bonding material. 3. Ultrasonic surgical instrument according to claim 2, characterized in that the first bonding material (7106a,b) is the same as the second bonding material. 4. Ultrasonic surgical instrument according to claim 2, characterized in that the first bonding material (7106a,b) is a solder bonding material and the second bonding material is a conductive epoxy bonding material. 5. Ultrasonic surgical instrument according to claim 4, characterized in that the solder bonding material is a metallic solder alloy bonding material. 6. Ultrasonic surgical instrument according to claim 1, characterized in that the first bonding material (7106a,b) is a solder alloy bonding material. 7. Ultrasonic surgical instrument according to claim 6, characterized in that the solder bonding material is a metallic solder alloy bonding material. 8. Ultrasonic surgical instrument according to claim 1, characterized in that a geometric axis of movement of the metallic waveguide (7102) is orthogonal to the geometric axes of polarization of the first and second piezoelectric ceramic elements. 9. Ultrasonic surgical instrument, according to claim 1, characterized in that the first connection material (7106a,b) is a metal alloy solder, and in which the first ceramic piezoelectric element (7104a) is connected to the metallic waveguide (7102) using metal alloy solder in an adhesive bonding process. 10. Ultrasonic surgical instrument, according to claim 1, characterized in that the first connection material (7106a,b) is a metal alloy solder, and in which the first ceramic piezoelectric element (7104a) is connected to the metallic waveguide (7102) using metal alloy solder in a metallurgical/chemical bonding process.