Ultrasonic transducer
The ultrasonic transducer integrates the front mass and horn as a single structure, using screw-type or prestressed bolts, reducing metal interfaces and air gaps, thus improving energy transfer and assembly efficiency.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Filing Date
- 2024-06-13
- Publication Date
- 2026-07-07
AI Technical Summary
Existing ultrasonic transducers have multiple metal interfaces that create air gaps, leading to energy dissipation and are difficult to assemble due to limited clamping surfaces.
The ultrasonic transducer design reduces metal interfaces by integrating the front mass and ultrasonic horn as a single structure, using screw-type or prestressed bolts to secure components, and incorporates openings and slots for improved assembly and compliance.
This design enhances energy transfer, reduces manufacturing costs, and simplifies assembly while maintaining high Q factor and dynamic response, with fewer air gaps and less energy dissipation.
Smart Images
Figure 2026522346000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to an ultrasonic transducer and a method of operating an ultrasonic transducer, and is not necessarily limited thereto, but is particularly for surgical applications.
Background Art
[0002] (Background of the Invention) Ultrasonic transducers are known in the art for various applications. One such application is an ultrasonic surgical device (for either hard or soft tissue) that employs ultrasonic vibrations to improve cutting performance, which utilizes a transducer mounted within a handheld device.
[0003] Prior art transducers are disclosed in FIGS. 29 and 30 of WO2023007013 and are reproduced as FIGS. 1A and 1B. FIG. 1A shows the transducer in a rear-side exploded perspective view, and FIG. 1B shows the transducer with the ultrasonic horn arrangement displaced in a front-side perspective view.
[0004] The transducer 100 has a back mass 101 and a front mass 102 (having a proximal portion 102a, an intermediate portion 102b, and a distal portion 102c), with an ultrasonic horn arrangement 103 located in front of the front mass. Two piezoelectric ceramic rings 107 of opposite polarity sandwich an electrode 106 and form a piezoelectric stack 108 (more broadly, an ultrasonic actuator arrangement) held between the back mass 101 and the front mass 102 by a prestress bolt 104 and a nut 105. The prestress bolt 104 applies and distributes prestress within the piezoelectric stack 108. The front mass 102 has an annular portion in the form of an outer cylindrical wall surrounding a longitudinal axis A. During operation, a drive signal is applied to the electrode 106, grounding the front mass 102 and the back mass 101 and causing vibration of the piezoelectric rings 107. The back mass 101, piezoelectric ceramic ring 107, electrode 106, front mass 102, and ultrasonic horn arrangement 103 are arranged along the longitudinal axis A of the transducer. Vibrations generated by the piezoelectric ceramic ring 107 are conducted along the vibration energy transmission path into the front mass 102 and the ultrasonic horn arrangement 103. The vibrations are then amplitude-amplified by the ultrasonic horn arrangement 103.
[0005] However, there are several limitations to the configuration of this transducer (i.e., the arrangement of the transducer's components). Firstly, there are several metal interfaces within the transducer. If such interfaces are not "tight," this creates an air gap that behaves as a dielectric layer. As a result, the two components do not "face" each other to the desired extent, leading to an undesirable increase in energy dissipation. Secondly, the transducer is relatively difficult to assemble because it is difficult to fully clamp the horn to the front mass. This is because there is a limited thickness (approximately 1 mm) on the ultrasonic horn arrangement that the clamping clamp can secure. [Overview of the Initiative] [Means for solving the problem]
[0006] (Summary of the invention) Generally, there is a need for apparatus and methods to solve one or more of the problems identified above.
[0007] An object of one or more aspects of the present invention is to provide an ultrasonic transducer that reduces the number of metal interfaces within the transducer.
[0008] An object of one or more aspects of the present invention is to provide an ultrasonic transducer that is easier to assemble than transducers known in the art.
[0009] Further objects and subjects of the present invention will become clear from the following description.
[0010] According to a first aspect of the present invention, an ultrasonic transducer for surgical use is provided, which ultrasonic transducer, Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement positioned in front of the front mass; and Equipped with a screw-type fastener, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The screw fastener extends through the back mass and ultrasonic actuator arrangement, and The screw fastener is coupled to the front mass or the ultrasonic horn arrangement.
[0011] The inventors have found that the ultrasonic transducer of the present invention has improved energy transfer, is less expensive, and / or easier to assemble compared to transducers known in the art.
[0012] "Coupling" means that the front mass or ultrasonic horn configuration is the mating partner of the screw fastener. In other words, one part of the screw fastener is located within the front mass or ultrasonic horn configuration.
[0013] Preferably, vibrations generated by the ultrasonic actuator arrangement are transmitted along the vibration energy transmission path into the front mass and the ultrasonic horn arrangement, and are amplitude-amplified by the ultrasonic horn arrangement.
[0014] One or more of the back mass, front mass, and ultrasonic horn arrangement may include multiple openings that open toward the longitudinal axis and intersect the vibration energy transmission path, and are configured to provide increased mechanical compliance in the direction along the vibration energy transmission path. Preferably, the front mass includes multiple openings. In some embodiments, the multiple openings are not provided within the ultrasonic horn arrangement.
[0015] The front mass may include one or more regions having multiple openings and one or more regions without openings. At least one region having multiple openings may be located between a region without openings and the ultrasonic horn arrangement. At least one region having multiple openings may be located between two regions without openings. Preferably, the regions extend in the circumferential direction.
[0016] The length of the transducer, measured along the vibration energy transmission path from the proximal end of the back mass to the distal end of the ultrasonic horn arrangement, is preferably 40 mm or less.
[0017] The maximum diameter of the transducer, measured perpendicular to its length, is preferably 15 mm or less.
[0018] The transducer may be a Langevin transducer. The ultrasonic actuator arrangement preferably comprises a piezoelectric stack. Preferably, the piezoelectric stack comprises an electrode and two piezoelectric ceramic rings of opposite polarities. The two piezoelectric ceramic rings sandwich the electrode.
[0019] The ultrasonic horn arrangement preferably comprises a blade, and the blade preferably has a curved and / or tapered profile.
[0020] In some embodiments, the threaded fastener couples to the ultrasonic horn arrangement. In these embodiments, the threaded fastener preferably extends through the back mass, the ultrasonic actuator arrangement, and the front mass and couples to the ultrasonic horn arrangement.
[0021] When compared to the prior art transducer shown in FIG. 1, the advantages associated with these embodiments include, but are not limited to, one or more of a high Q factor; a higher gain; and a higher dynamic response from a low voltage. Further, these embodiments are easier to assemble than the prior art transducer shown in FIG. 1 because, at least in part, the clamping of the components is not so tight.
[0022] The threaded fastener may be a bolt, and may also be referred to as a prestress bolt. The prestress bolt is used to apply and distribute prestress within the ultrasonic actuator arrangement. The prestress bolt preferably comprises a threaded portion and a head.
[0023] In some embodiments, the head of the prestress bolt is adjacent to the back mass.
[0024] The prestress bolt may be an M3 bolt, preferably an M3x20mm bolt.
[0025] The front mass may have an outer diameter of from about 3 mm to about 13 mm, or from about 4 mm to about 12 mm, or from about 5 mm to about 11 mm, or from about 6 mm to about 10 mm. The front mass may have an inner diameter of from about 1 mm to about 8 mm, or from about 1 mm to about 7 mm, or from about 2 mm to about 6 mm, or from about 3 mm to about 5 mm. This relatively large diameter has the advantage of allowing larger openings when the front mass includes a plurality of openings.
[0026] The front mass may include one or more clamping slots. The purpose of the slots is to improve the ease of assembly of the transducer. The slots facilitate the holding of the tightening clamp to the front mass. The slots are preferably in a region of the front mass without an opening. To avoid misunderstanding, the one or more clamping slots are different from the plurality of openings described above, serve different purposes, and provide different technical effects.
[0027] In some embodiments, a screw fastener is coupled to the front mass. In these embodiments, the front mass and the ultrasonic horn arrangement preferably form an integral structure. The front mass and the ultrasonic horn arrangement may be attached together (e.g., welded), but it is preferred that the front mass and the ultrasonic horn arrangement be formed as a single structure (e.g., by using computer numerical control technology).
[0028] The inventors of the present invention have found that, compared to transducers known in the art, the ultrasonic transducers according to these embodiments not only have a lower manufacturing cost but also have fewer metal interfaces. This is because the fewer the interfaces, the fewer the air gaps and the less undesirable energy dissipation, thus improving the performance of the ultrasonic transducer.
[0029] Furthermore, forming the front mass and the ultrasonic horn arrangement as an integral structure increases the mass that the tightening clamp can hold, which promotes easier assembly.
[0030] The front mass may include one or more regions having multiple openings and one or more regions without openings. Preferably, the threaded fastener is coupled to the region of the front mass without openings, and the region of the front mass without openings is adjacent to the ultrasonic actuator arrangement. This is advantageous because the region of the front mass having multiple openings is not prestressed by the bolts (i.e., the openings are not under compression and are not affected by the stiffness of the threaded fastener).
[0031] The threaded fastener may be a bolt, sometimes called a prestressed bolt. Prestressed bolts are used to apply and distribute prestress within an ultrasonic actuator arrangement. Prestressed bolts preferably comprise a threaded portion and a head. In some embodiments, the head of the prestressed bolt is adjacent to the back mass.
[0032] The prestressed bolt may be an M3 bolt, preferably an M3x12mm bolt.
[0033] The front mass may be tapered, and preferably it is tapered (narrows towards the ultrasonic horn arrangement). That is, the widest diameter of the front mass is in the region adjacent to the ultrasonic actuator arrangement, and the narrowest diameter of the front mass is in the region adjacent to the ultrasonic horn arrangement.
[0034] The front mass may have one or more slots. The purpose of the slots is to improve the ease of assembly of the transducer. The slots facilitate the retention of the clamping clamp on the front mass. The slots are preferably located in an area of the front mass that does not have an opening.
[0035] Instead of a prestressed bolt (having a head and a single threaded portion), the threaded fastener may be a double-ended bolt. Preferably, the double-ended bolt comprises a central (preferably unthreaded) portion, a first threaded portion, and a second threaded portion. The first and second threaded portions extend from the central portion in opposite directions. Preferably, the first threaded portion has a first radius, the second threaded portion has a second radius, and the first radius is different from the second radius. In other words, the double-ended bolt preferably comprises two threaded portions with different radii.
[0036] The first threaded portion is preferably coupled to the front mass. The second threaded portion preferably extends through the back mass and the ultrasonic actuator arrangement. Therefore, when assembled, the central portion may preferably be positioned between the ultrasonic actuator arrangement and the front mass.
[0037] The second threaded portion may be coupled with a nut positioned adjacent to the back mass.
[0038] The central portion may have a diameter of approximately 5 mm to 11 mm, or approximately 6 mm to 10 mm, or approximately 7 mm to 9 mm, or approximately 8 mm. The central portion may have a diameter of at least approximately 5 mm. The central portion may have a diameter of approximately 11 mm or less.
[0039] The first threaded portion may have a diameter of approximately 3 mm to approximately 9 mm, or approximately 4 mm to approximately 8 mm, or approximately 5 mm to approximately 7 mm, or approximately 6 mm. The first threaded portion may have a diameter of at least approximately 3 mm. The first threaded portion may have a diameter of approximately 9 mm or less.
[0040] The first threaded portion may have a length of approximately 1 mm to approximately 6 mm, or approximately 1 mm to approximately 5 mm, or approximately 2 mm to approximately 4 mm, or approximately 3 mm. The first threaded portion may have a length of at least approximately 1 mm. The first threaded portion may have a length of approximately 6 mm or less.
[0041] The first threaded portion may be an M6 thread, preferably an M6x3mm thread.
[0042] The second threaded portion may have a diameter of approximately 1 mm to approximately 6 mm, or approximately 1 mm to approximately 5 mm, or approximately 2 mm to approximately 4 mm, or approximately 3 mm. The second threaded portion may have a diameter of at least approximately 1 mm. The second threaded portion may have a diameter of approximately 6 mm or less.
[0043] The second threaded portion may have a length of approximately 7 mm to approximately 13 mm, or approximately 8 mm to approximately 12 mm, or approximately 9 mm to approximately 11 mm, or approximately 10 mm. The second threaded portion may have a length of at least approximately 7 mm. The second threaded portion may have a length of approximately 13 mm or less.
[0044] The second threaded portion may be an M3 thread, preferably an M3x10mm thread.
[0045] The front mass may have an outer diameter of approximately 3 mm to 11 mm, or approximately 4 mm to 10 mm, or approximately 5 mm to 9 mm, or approximately 6 mm to 8 mm. This relatively large diameter has the advantage of allowing for larger openings if the front mass contains multiple openings.
[0046] Preferably, the double-ended bolt is made of titanium or contains at least titanium.
[0047] The central portion of the double-ended bolt may have one or more slots for receiving a clamping clamp.
[0048] Ultrasonic transducers may be for surgical, therapeutic, and / or diagnostic applications. To avoid misunderstanding, these applications also include dentistry. Ultrasonic transducers may be for human and / or animal applications.
[0049] According to a second aspect of the present invention, an ultrasonic transducer for surgical use is provided, which ultrasonic transducer, Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement positioned in front of the front mass; and Equipped with a screw-type fastener, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer, and The screw fastener extends through the back mass, the ultrasonic actuator arrangement, and the front mass and connects to the ultrasonic horn arrangement.
[0050] Embodiments of a second aspect of the present invention may include one or more features or embodiments thereof of a first aspect of the present invention, and vice versa.
[0051] According to a third aspect of the present invention, an ultrasonic transducer for surgical use is provided, which ultrasonic transducer, Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement in front of the front mass, wherein the front mass and the ultrasonic horn arrangement form an integrated structure; and Equipped with a screw-type fastener, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The screw fastener extends through the back mass and ultrasonic actuator arrangement, and The screw-type fastener is connected to the front mass.
[0052] Embodiments of a third aspect of the present invention may include one or more features or embodiments thereof of the first and second aspects of the present invention, and vice versa.
[0053] According to a fourth aspect of the present invention, an ultrasonic transducer for surgical use is provided, which ultrasonic transducer, Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement in front of the front mass, wherein the front mass and the ultrasonic horn arrangement form an integrated structure; and Equipped with prestress bolts, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The prestressed bolt extends through the back mass and ultrasonic actuator arrangement, and The prestressed bolt is connected to the front mass.
[0054] Embodiments of the fourth aspect of the present invention may include one or more features or embodiments thereof of the first to third aspects of the present invention, and vice versa.
[0055] According to a fifth aspect of the present invention, an ultrasonic transducer for surgical use is provided, which ultrasonic transducer, Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement in front of the front mass, wherein the front mass and the ultrasonic horn arrangement form an integrated structure; and Equipped with double-ended bolts, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The double-ended bolt extends through the back mass and ultrasonic actuator arrangement, and The double-ended bolt connects to the front mass.
[0056] Embodiments of the fifth aspect of the present invention may include one or more features or embodiments thereof of the first to fourth aspects of the present invention, and vice versa.
[0057] According to a sixth aspect of the present invention, a component kit is provided that includes components usable for assembling an ultrasonic transducer according to any one of the first to fifth aspects of the present invention.
[0058] Embodiments of the sixth aspect of the present invention may include one or more features or embodiments thereof of the first to fifth aspects of the present invention, and vice versa.
[0059] According to a seventh aspect of the present invention, a surgical tool is provided comprising an ultrasonic transducer according to any one of the first to fifth aspects of the present invention.
[0060] The surgical tool may further comprise one or more of a casing, a clamp jaw, and a mechanism for actinguating the clamp jaw.
[0061] Surgical tools may be operated by humans or by programmable machines such as robots.
[0062] Embodiments of the seventh aspect of the present invention may include one or more features or embodiments thereof of the first to sixth aspects of the present invention, and vice versa.
[0063] According to an eighth aspect of the present invention, a method for operating an ultrasonic transducer according to any one of the first to fifth aspects of the present invention is provided.
[0064] This method preferably involves applying an electrical signal to an ultrasonic actuator arrangement to generate vibrations that are to be transmitted along a vibration energy transmission path within the front mass and into the ultrasonic horn arrangement. Preferably, the vibrations are amplitude-amplified by the ultrasonic horn arrangement.
[0065] Ultrasonic transducers range from 10 to 1000 W / cm². -2 It may operate at power densities in the range of . The ultrasonic transducer may operate at power in the range of 1 to 1000 W.
[0066] Embodiments of the eighth aspect of the present invention may include one or more features or embodiments thereof of the first to seventh aspects of the present invention, and vice versa. [Brief explanation of the drawing]
[0067] Hereinafter, various embodiments of the present invention will be described with reference to the drawings, for illustrative purposes only.
[0068] [Figure 1] Figure 1 shows a prior art transducer in a rear exploded perspective view (Figure 1A) and a front perspective view (Figure 1B). [Figure 2] Figure 2 shows a transducer according to an embodiment of the present invention in a side perspective view (Figure 2A), an exploded side perspective view (Figure 2B), a side view (Figure 2C), and a cross-sectional view along the longitudinal axis A (Figure 2D). [Figure 3] Figure 3 shows a transducer according to an embodiment of the present invention in a side perspective view (Figure 3A), an exploded side perspective view (Figure 3B), a side view (Figure 3C), and a cross-sectional view along the longitudinal axis A (Figure 3D). [Figure 4] Figure 4 shows a transducer according to an embodiment of the present invention in a side perspective view (Figure 4A), an exploded side perspective view (Figure 4B), a side view (Figure 4C), and a cross-sectional view along the longitudinal axis A (Figure 4D). [Modes for carrying out the invention]
[0069] (Detailed description of preferred embodiments) The present invention will be described below with reference to Figures 2 to 4.
[0070] Referring to Figure 2, a transducer according to an embodiment of the present invention is generally shown as 200. The transducer has a back mass 201 and a front mass 202, with an ultrasonic horn arrangement 203 located in front of the front mass 202. Two piezoelectric ceramic rings 207 of opposite polarity form a piezoelectric stack 208 (i.e., ultrasonic actuator arrangement) with an electrode 206 in between. The back mass 201, piezoelectric stack 208, front mass 202, and ultrasonic horn arrangement 203 are arranged along the longitudinal axis A of the transducer 200.
[0071] The piezoelectric stack 208 is held between the back mass 201 and the front mass 202 by a threaded fastener, which is (in this particular embodiment) a prestressed bolt 204. In this embodiment, the prestressed bolt 204 is an M3 × 20 mm bolt. However, it will be understood that the type of bolt is not so limited and depends on the desired size of the transducer. The head of the bolt 204a is positioned adjacent to the back mass 201. The threaded portion of the prestressed bolt 204 extends through the back mass 201, the piezoelectric stack 208 and the front mass 202 and is coupled to the ultrasonic horn arrangement 203.
[0072] In this embodiment, the front mass 202 has an arrangement of openings (i.e., holes) 209 formed through it. The openings are oriented toward the longitudinal axis A, intersect the vibration energy transmission path, and provide improved axial mechanical compliance parallel to the longitudinal axis A and along the vibration energy path.
[0073] The front mass 202 has a proximal portion 202a, an intermediate portion 202b, and a distal portion 202c. The proximal portion 202a is in contact with the piezoelectric stack 208. The threaded portion of the prestress bolt 204 is coupled to the proximal portion 202a of the front mass 202. An opening 209 is formed in the intermediate portion 202b. The proximal portion 202a and the distal portion 202c do not have openings. Instead, the proximal portion 202a has one or more slots 210. The purpose of the slots 210 is to improve the ease of assembly of the transducer 200. The slots 210 facilitate the retention of the clamping clamp on the front mass 202.
[0074] The distal portion 202c is in contact with the ultrasonic horn arrangement 203. The proximal portion 202a, intermediate portion 202b, and distal portion 202c of the front mass 202 are integrally formed with each other and have substantially the same outer diameter (ignoring the effect of the presence of the opening 209 on the outer diameter).
[0075] Referring to Figure 3, a transducer according to an embodiment of the present invention is generally shown as 300. The transducer has a back mass 301 and a front mass 302, with an ultrasonic horn arrangement 303 located in front of the front mass 302. Two piezoelectric ceramic rings 307 of opposite polarity form a piezoelectric stack 308 (i.e., ultrasonic actuator arrangement) with an electrode 306 in between. The back mass 301, piezoelectric stack 308, front mass 302, and ultrasonic horn arrangement 303 are arranged along the longitudinal axis A of the transducer 300. The front mass 302 and ultrasonic horn arrangement 303 together form a single structure. In this embodiment, the front mass 302 and ultrasonic horn arrangement 303 are manufactured as a single component (i.e., not manufactured separately and then mounted).
[0076] The piezoelectric stack 308 is held between the back mass 301 and the front mass 302 by a threaded fastener, which is (in this particular embodiment) a prestressed bolt 304. In this embodiment, the prestressed bolt 304 is an M3 × 12 mm bolt. However, it will be understood that the type of bolt is not so limited and depends on the desired size of the transducer. The head of the bolt 304a is positioned adjacent to the back mass 301. The threaded portion of the prestressed bolt 304 extends through the back mass 301 and the piezoelectric stack 308 and connects to the front mass 302.
[0077] In this embodiment, the front mass 302 has an arrangement of openings (i.e., holes) 309 formed through it. The openings are oriented toward the longitudinal axis A, intersect the vibration energy transmission path, and provide improved axial mechanical compliance parallel to the longitudinal axis A and along the vibration energy path.
[0078] The front mass 302 has a proximal portion 302a, an intermediate portion 302b, and a distal portion 302c. The proximal portion 302a is in contact with the piezoelectric stack 308. The threaded portion of the prestress bolt 304 is coupled to the intermediate portion 302b of the front mass 302. An opening 309 is formed in the distal portion 302c. The proximal portion 302a and the intermediate portion 302b do not have openings. Instead, the proximal portion 302a has one or more slots 310. The purpose of the slots 310 is to improve the ease of assembly of the transducer 300. The slots 310 facilitate the retention of the clamping clamp on the front mass 302.
[0079] The distal portion 302c is in contact with the ultrasonic horn arrangement 303. The proximal portion 302a, intermediate portion 302b, and distal portion 302c of the front mass 302 are integrally formed with respect to each other.
[0080] The diameter of the proximal portion 302a is greater than the diameter of the distal portion 302c. The intermediate portion 302b has a tapered profile such that its widest diameter is equal to the diameter of the proximal portion 302a and its narrowest diameter is equal to the diameter of the distal portion 302c. Therefore, the front mass 302 can be said to be a tapered front mass.
[0081] Referring to Figure 4, a transducer according to an embodiment of the present invention is generally shown as 400.
[0082] The transducer has a back mass 401 and a front mass 402, with an ultrasonic horn arrangement 403 located in front of the front mass 402. Two piezoelectric ceramic rings 407 with opposite polarity form a piezoelectric stack 408 (i.e., ultrasonic actuator arrangement) with an electrode 406 in between. The back mass 401, piezoelectric stack 408, front mass 402, and ultrasonic horn arrangement 403 are arranged along the longitudinal axis A of the transducer 400. The front mass 402 and ultrasonic horn arrangement 403 together form a single structure. In this embodiment, the front mass 402 and ultrasonic horn arrangement 403 are manufactured as a single component (i.e., not manufactured separately and then mounted).
[0083] The piezoelectric stack 408 is held between the back mass 401 and the front mass 402 by a threaded fastener, which is (in this particular embodiment) a double-ended bolt 404. The double-ended bolt 404 has a central portion 404a and two threaded portions (a first threaded portion 404b and a second threaded portion 404c). The two threaded portions 404b, 404c are on adjacent faces of the central portion 404a and extend in opposite directions. The diameter of the central portion 404a is greater than the diameter of the first threaded portion 404b, and the diameter of the first threaded portion 404b is greater than the diameter of the second threaded portion 404c.
[0084] The first threaded portion 404b is coupled to the front mass 402. The second threaded portion 404c extends through the back mass 401 and the piezoelectric stack 408 and is coupled to a nut 405 positioned adjacent to the back mass 401 (i.e., on the face of the back mass 401 opposite to the face adjacent to the piezoelectric stack 408). The inner diameter of the nut 405 is selected in a manner known in the art to match the outer diameter of the threaded portion 404c. The second threaded portion 404c prestresses the piezoelectric stack 408.
[0085] In this embodiment, the front mass 402 has an arrangement of openings (i.e., holes) 409 formed through it. The openings are oriented toward the longitudinal axis A, intersect the vibration energy transmission path, and provide improved axial mechanical compliance parallel to the longitudinal axis A and along the vibration energy path.
[0086] The front mass 402 has a proximal portion 402a and a distal portion 402c. The proximal portion 402a is in contact with the piezoelectric stack 408. An opening 409 is formed in the distal portion 402c. The distal portion 402c is in contact with the ultrasonic horn arrangement 403. The proximal portion 402a and distal portion 402c of the front mass 402 are integrally formed with each other and have substantially the same outer diameter (ignoring the effect of the presence of the opening 409 on the outer diameter).
[0087] The first threaded portion 404b is coupled to the proximal portion 402a of the front mass 402. This means that the bolt 404 does not connect to the region of the front mass 402 having the opening 409, and therefore does not interfere with the advantageous technical effects provided by the presence of the opening 409.
[0088] The central portion 404a of the double-ended bolt 404 has one or more slots 410. The purpose of the slots 410 is to improve the ease of assembly of the transducer 400. The slots 410 facilitate the clamping of the central portion 404a, allowing the nut 405 and ultrasonic horn arrangement 403 to be screwed onto the double-ended bolt 404. Furthermore, the entire ultrasonic horn arrangement 403 can be advantageously held by the tightening clamp when screwed in. This is in comparison to the transducers of prior art (Figures 1 and 2) which can only hold a very small portion (about 1 mm) of the horn 103.
[0089] In each embodiment, the ultrasonic horn arrangements 203, 303, 403 include blades 211, 311, 411 shaped according to the desired effect / application. In these embodiments, the blades 211, 311, 411 have a curved tapered profile such that the cross-sectional area at the distal end (i.e., distal to the front masses 202, 302, 402) is larger than the cross-sectional area at the proximal end.
[0090] Each embodiment operates in a manner similar to the prior art transducer shown in Figure 1. An electrically driven signal is applied to electrodes 206, 306, and 406, grounding the front masses 202, 302, and 402 and the back masses 201, 301, and 401, causing vibrations in the piezoelectric rings 207, 307, and 407. The vibrations generated by the piezoelectric ceramic rings 207, 307, and 407 are conducted along the vibration energy transmission path into the front masses 202, 302, and 402 and into the ultrasonic horn arrangements 203, 303, and 403. The vibrations are then amplitude-amplified by the ultrasonic horn arrangements 203, 303, and 403.
[0091] Each embodiment can be used in a surgical tool. In addition to the ultrasonic transducer, the surgical tool may include, for example, one or more of a casing, a clamp jaw, and a mechanism for acting on the clamp jaw.
[0092] Ultrasonic transducers 200, 300, and 400 for surgical applications are disclosed. The ultrasonic transducer comprises a back mass 201, 301, 401; a front mass 202, 302, 402; an ultrasonic actuator arrangement 208, 308, 408 held between the back mass and the front mass; an ultrasonic horn arrangement 203, 303, 403 in front of the front mass; and screw fasteners 204, 304, 404. The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The screw fasteners extend through the back mass and ultrasonic actuator arrangement and are coupled to the front mass or ultrasonic horn arrangement. The ultrasonic transducer has improved energy transfer and is less expensive and / or easier to assemble.
[0093] Throughout this specification, unless the context explicitly requires otherwise, the words “comprise” or “include,” or variations such as “comprises” or “comprising,” “includes” or “including,” shall be understood to mean the inclusion of the integer or group of integers described, but not the exclusion of any other integer or group of integers. Furthermore, unless the context explicitly requires otherwise, the term “or” shall be interpreted as inclusive, not exclusive.
[0094] The above description of the invention is presented for illustrative and explanatory purposes only and is not intended to be exhaustive or to limit the invention to the exact form disclosed. The embodiments described are selected and described to best illustrate the principles of the invention and its practical applications, thereby enabling those skilled in the art to best utilize the invention with various embodiments and modifications suitable for specific intended applications. Accordingly, further modifications or improvements may be incorporated without departing from the scope of the invention as defined by the appended claims.
Claims
1. An ultrasonic transducer for surgical use, The ultrasonic transducer is Backmas; Front mass; An ultrasonic actuator arrangement positioned between the back mass and the front mass; An ultrasonic horn arrangement positioned in front of the front mass; and Equipped with a screw-type fastener, The back mass, ultrasonic actuator arrangement, front mass, and ultrasonic horn arrangement are arranged along the longitudinal axis of the transducer. The screw fastener extends through the back mass and ultrasonic actuator arrangement, and The screw fastener is coupled to the front mass or the ultrasonic transducer.
2. The ultrasonic transducer according to claim 1, wherein one or more of the back mass, front mass, and ultrasonic horn arrangements include a plurality of openings that open toward the longitudinal axis, intersect the vibration energy transmission path, and are configured to provide increased mechanical compliance in the direction along the vibration energy transmission path.
3. The ultrasonic transducer according to claim 1 or 2, wherein the front mass includes a plurality of openings.
4. The ultrasonic transducer according to any one of claims 1 to 3, wherein the ultrasonic actuator arrangement comprises a piezoelectric stack.
5. The ultrasonic transducer according to any one of claims 1 to 4, wherein the ultrasonic horn arrangement comprises blades having a curved and / or tapered profile.
6. The ultrasonic transducer according to any one of claims 1 to 5, wherein the screw fastener extends through the front mass and is coupled to the ultrasonic horn arrangement.
7. The ultrasonic transducer according to claim 6, wherein the screw fastener extends through the back mass, the ultrasonic actuator mounting section, and the front mass.
8. The ultrasonic transducer according to claim 7, wherein the screw fastener is a prestressed bolt.
9. The ultrasonic transducer according to claim 8, wherein the prestressed bolt comprises a threaded portion and a head, the head of the prestressed bolt being adjacent to the back mass.
10. The ultrasonic transducer according to any one of claims 1 to 5, wherein the screw fastener is coupled to the front mass.
11. The ultrasonic transducer according to claim 10, wherein the front mass and ultrasonic horn arrangement form an integrated structure.
12. The ultrasonic transducer according to claim 10 or 11, wherein the screw fastener is a prestressed bolt.
13. The ultrasonic transducer according to claim 12, wherein the prestressed bolt comprises a threaded portion and a head, the head of the prestressed bolt being adjacent to the back mass.
14. The ultrasonic transducer according to claim 12 or 13, wherein the front mass is tapered toward the ultrasonic horn arrangement.
15. The ultrasonic transducer according to claim 10 or 11, wherein the screw fastener is a double-ended bolt having two threaded portions of different radii.
16. The ultrasonic transducer according to claim 15, wherein the double-ended bolt comprises a central portion, a first threaded portion, and a second threaded portion.
17. The ultrasonic transducer according to claim 16, wherein the first threaded portion is coupled to the front mass, and the second threaded portion extends through the back mass and the ultrasonic actuator arrangement.
18. The ultrasonic transducer according to claim 17, wherein the second threaded portion is coupled to a nut positioned adjacent to the back mass.
19. A parts kit comprising parts usable for assembly into an ultrasonic transducer according to any one of claims 1 to 18.
20. A surgical tool comprising an ultrasonic transducer according to any one of claims 1 to 18.
21. A method for operating an ultrasonic transducer according to any one of claims 1 to 18, comprising applying an electrical signal to the ultrasonic actuator arrangement to generate vibrations to be transmitted within the front mass and within the ultrasonic horn arrangement along a vibration energy transmission path.