Ultrasonic surgical instrument for surgery

Abstract

Provided is an ultrasonic surgical instrument for surgery capable of smoothly performing a cutting operation while preventing a treatment target part from being left uncut. This ultrasonic surgical instrument for surgery has a cutting tip connected to a vibrator that generates longitudinal vibration. This cutting tip has a vibration conversion mechanism that converts longitudinal vibration into composite vibration including a torsional vibration component around a longitudinal axis, and a cutting part that is connected to the vibration conversion mechanism at a proximal end and cuts a treatment target part at a distal end. The cutting part has a cutting surface that is radially oriented about the longitudinal axis and compositely vibrates about the longitudinal axis. The cutting surface has a plurality of pyramids each aligned from the distal end of the cutting tip and each having a protrusion vertex. The cutting surface is formed such that, when defining the amplitude of the composite vibration of each of the protrusion vertices of the plurality of pyramids as d1, and the protrusion interval, which is the distance between adjacent protrusion vertices of the plurality of pyramids, as Ld1, the relationship between the amplitude d1 and the protrusion interval Ld1 satisfies 2×d1≥Ld1.

Description

Surgical ultrasonic surgical instrument

[0001] The present invention relates to an external ultrasonic surgical instrument.

[0002] As an example of an external ultrasonic surgical instrument, there is a surgical handpiece disclosed in Patent Document 1. In this surgical handpiece, an ultrasonic chip that provides both longitudinal vibration and torsional vibration in the longitudinal axis direction is used. The ultrasonic chip includes a cylindrical shaft having a longitudinal axis extending between a proximal end and a distal end, and the proximal end and the distal end have a first diameter and a second diameter, respectively, and the first diameter is larger than the second diameter. The ultrasonic chip also includes a cutting functional part connected to the distal end of the shaft. The shaft defines a suction lumen extending along the longitudinal axis of the shaft.

[0003] Japanese Patent Publication No. 2022-502222

[0004] In the prior art, there may be a case where the treated part by the ultrasonic chip is left uncut.

[0005] In the prior art, there may be a case where it is not sufficient to suppress the overall heat generation while maintaining the strength of the shaft provided with the cutting functional part in the ultrasonic chip.

[0006] Therefore, the present invention has been made in view of the above problems of the prior art, and one of the purposes is to provide a surgical ultrasonic surgical instrument that prevents the uncut part of the cutting treatment target part and enables a smooth cutting operation of a deep groove. Another purpose is to provide a surgical ultrasonic surgical instrument that can suppress the overall heat generation of the ultrasonic chip while maintaining the strength of the ultrasonic chip.

[0007] The ultrasonic surgical instrument for surgical use according to the present invention comprises: a transducer that generates longitudinal vibrations, which are ultrasonic vibrations in the direction of the longitudinal axis; a vibration conversion mechanism connected to the transducer that converts the longitudinal vibrations into compound vibrations including a torsional vibration component in the torsional direction around the longitudinal axis; a cutting tip that extends from the proximal end to the distal end and is connected to the vibration conversion mechanism at the proximal end and has a cutting section at the distal end for cutting the part to be treated, and transmits the compound vibrations to the cutting section; the cutting section has a cutting surface that vibrates compoundly around the longitudinal axis in the radial direction around the axis of the longitudinal axis; the cutting surface has a plurality of pyramids, each aligned from the distal end of the cutting tip, each having a projection vertex; and if the amplitude of the compound vibration of each of the projection vertices of the plurality of pyramids is d1, and the distance between adjacent projection vertices of the plurality of pyramids is Ld1, then the relationship between the amplitude d1 and the projection interval Ld1 is given by the following equation: It is characterized by being formed such that 2 × d1 ≥ Ld1.

[0008] According to the ultrasonic surgical device of the present invention, when performing cutting operations on a target area such as bone, it is possible to prevent incomplete removal of material from the target area and to perform smooth and deep groove cutting operations on the target area.

[0009] In the surgical ultrasonic surgical instrument according to an embodiment of the present invention, the plurality of pyramids preferably include pyramids in which at least the first two rows from the distal end of the cutting tip are formed to be higher than the subsequent rows, and the lower pyramids thereafter.

[0010] According to the ultrasonic surgical instrument of the present invention, when the tall pyramidal tip at the distal end of the cutting tip is inserted obliquely into the target area such as bone to cut a groove, the distal end of the cutting tip can cut a deep groove in the target area in one go, making it possible to cut a groove of the required depth with fewer operations. In addition, since the lower pyramidal tip cuts the shallower portion before the taller pyramidal tip, the amount of material removed by the taller pyramidal tip can be reduced, allowing for a smoother cutting operation with less snagging. Furthermore, since the amplitude of the compound vibration at the tip apex of the projection of the taller pyramidal tip, which is farther from the center of the longitudinal axis, is increased, the cutting force is enhanced.

[0011] In the ultrasonic surgical instrument according to an embodiment of the present invention, it is preferable that the plurality of pyramidal shapes are formed such that their height gradually decreases from the highest distal end of the cutting tip toward the proximal end of the cutting tip. This allows the cutting tip to cut while pulling on a larger area of ​​the treatment target.

[0012] In the ultrasonic surgical instrument according to an embodiment of the present invention, it is preferable that the tallest pyramidal tip at the distal end of the cutting tip, among the plurality of pyramidal tips, is formed thinly by creating a concave curved surface on the side toward the proximal end of the cutting tip. As a result, the area near the tip apex of the tall pyramidal projection that is farther away from the center of the longitudinal axis becomes thinner, thereby further increasing the cutting force.

[0013] In the ultrasonic surgical instrument according to an embodiment of the present invention, it is preferable that the cutting surface is formed to encircle the longitudinal axis. This allows for further scraping of cutting residue from the treatment area on both sides in the direction of the cutting tip's pull, thereby enabling groove cutting to the required depth.

[0014] In the ultrasonic surgical instrument according to an embodiment of the present invention, it is preferable that the plurality of pyramidal projections on the cutting surface are formed to be spirally aligned around the longitudinal axis. This increases the cutting force exerted by the apex of the pyramidal projection of the cutting tip.

[0015] In the ultrasonic surgical instrument of the embodiment of the present invention, it is preferable that the cutting surface includes a leading pyramid lower than the lower pyramid in the first row at the very front of the cutting tip, and that a deeper valley is formed between the leading pyramid and the highest pyramid in the second row from the very front of the cutting tip, deeper than the valley between the lower pyramids. As a result, the lower leading pyramid cuts the shallow part of the area to be treated before the highest pyramid, so that the amount cut by the highest pyramid can be reduced, enabling groove cutting operations to be performed more smoothly and without snagging.

[0016] In the ultrasonic surgical instrument for surgical use according to an embodiment of the present invention, it is preferable that at least the taller pyramids among the plurality of pyramids have an uneven tip shape having a plurality of divided protruding vertices and valleys between them, with the tip of the protruding vertex being divided. The uneven tip shape of each of the plurality of pyramids makes it possible to reduce the spacing between adjacent pyramids and prevent the tips of each pyramid from becoming too thin.

[0017] In the ultrasonic surgical instrument for surgical use according to an embodiment of the present invention, it is preferable that the plurality of pyramidal structures are formed with an uneven tip shape having a plurality of divided protruding vertices and valleys between them, obtained by dividing the tip of the protruding vertex. The uneven tip shape of each pyramidal structure makes it possible to reduce the spacing between adjacent pyramidal structures and prevent the tips of each pyramidal structure from becoming too thin.

[0018] In the ultrasonic surgical instrument for surgical use according to an embodiment of the present invention, the cutting portion has a cylindrical portion that is coaxial with the trunk of the cutting tip, has a diameter larger than the diameter of the trunk, and supports the cutting surface. The cutting surface is preferably formed on one side surface of the cylindrical portion such that, where TL1 is the distance between the vertices of the protrusions of the furthest pyramidal pyramids in a direction perpendicular to the longitudinal axis, and TL2 is the diameter of the cylindrical portion, the following condition, TL1 ≥ TL2, is satisfied. This prevents the occurrence of such deflection vibrations, even though when the cutting portion is formed in a hook shape, the volume of the raised portion of the cutting surface increases, which may disrupt the balance between the upper and lower parts and cause deflection vibrations to occur throughout the cutting tip.

[0019] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, it is preferable that each of the plurality of pyramidal surfaces has a blade-shaped tip at the apex of the projection, and that it has two first lateral ridges extending from the blade-shaped tip inclined in the direction of the longitudinal axis from the twist direction, and a second lateral ridge intersecting the first lateral ridge more steeply than the first lateral ridge at the blade-shaped tip.

[0020] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, each of the plurality of pyramidal structures is a square pyramidal structure, and when the cutting surface is viewed from above, the square pyramidal structure is configured such that the diagonal corresponding to the first side edge is longer than the diagonal corresponding to the second side edge, and the first side edge extends inclined from the torsional direction towards the longitudinal axis.

[0021] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, it is preferable that each of the plurality of pyramidal shapes, when viewed from above, has a square pyramidal shape on the side of the projection apex, and a hexagonal pyramidal shape on the side of the square pyramidal shape, with the lower part of the square pyramidal shape having triangular slopes with the lower ends of each of the first side edges as apex.

[0022] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, the cutting surface preferably has a V-shaped cutting path facing the slope, which is created to extend along the longitudinal axis between adjacent hexagonal pyramids.

[0023] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, it is preferable that the cutting surface has a helical path created between adjacent pyramidal surfaces so as to extend spirally along the axis of the longitudinal axis.

[0024] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, the cutting portion has a cylindrical portion that is coaxial with the trunk of the cutting tip, has a diameter larger than the diameter of the trunk, and supports the cutting surface, and the cutting surface is preferably formed on one side surface of the cylindrical portion such that it has a cylindrical surface without the pyramidal area between the trunk of the cutting tip and the cutting surface.

[0025] In a surgical ultrasonic surgical instrument of a further embodiment of the present invention, the cutting tip is a tubular body having a hollow portion that penetrates the cutting portion from the proximal end to the distal end, and it is preferable that the cutting tip has a thin-walled portion that is thinner than other portions arranged opposite to it in a direction intersecting the longitudinal axis so as to extend from the proximal end to the distal end along the radial direction toward the cutting surface and the longitudinal axis.

[0026] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, the cutting tip preferably has a through-hole in the thick portion that penetrates from the hollow portion through a thick portion which is thicker than the thin portion, to the outside of the cutting tip.

[0027] In a further embodiment of the present invention, a surgical ultrasonic surgical instrument is preferably further comprising a sheath tube that exposes the cutting portion and covers the vibration conversion mechanism and the cutting tip, defining a fluid flow path between the vibration conversion mechanism and the cutting tip, and a sealing mechanism that liquid-tightly seals the vibration conversion mechanism from the fluid flow path.

[0028] In a further embodiment of the present invention, in a surgical ultrasonic surgical instrument, the sealing mechanism preferably has an O-ring that seals the cutting tip at a position near the node of the torsional vibration caused by the vibration conversion mechanism.

[0029] According to a further embodiment of the present invention, it is possible to increase cutting efficiency and suppress overall heat generation of the cutting tip while maintaining the strength of the cutting tip.

[0030] This is a schematic perspective view illustrating the general appearance of an ultrasonic surgical instrument, which is an embodiment of the present invention. This is a longitudinal cross-sectional view illustrating the longitudinal cross-sectional structure of an ultrasonic surgical instrument, which is an embodiment of the present invention. This is a graph illustrating the standing wave corresponding to the ultrasonic vibration generated by the transducer when the transducer is electrically controlled in an embodiment of the present invention. This is a partially cutaway side view showing the internal longitudinal cross-section of the front side of an ultrasonic surgical instrument to show the configuration of the cutting tip of an ultrasonic surgical instrument, which is an embodiment of the present invention. This is a schematic perspective view from below looking upward, showing the cutting part of the cutting tip of an ultrasonic surgical instrument, which is Embodiment 1 of the present invention. This is a partial plan view of the cutting surface when the cutting part of the cutting tip of the ultrasonic surgical instrument, which is Embodiment 1, is viewed from the radial direction around the axis of the longitudinal axis. This is an enlarged partial plan view when viewed from the plan, schematically showing one of a plurality of square pyramids formed on the cutting surface of the cutting part of the cutting tip of the ultrasonic surgical instrument, which is Embodiment 1. This is an enlarged partial plan view of the cutting surface when the cutting part of the cutting tip of the ultrasonic surgical instrument, which is Embodiment 1, is viewed from the radial direction around the axis of the longitudinal axis. This is an enlarged partial plan view of the cutting surface of the cutting tip of the surgical ultrasonic surgical instrument of Example 1, viewed from the radial direction around the longitudinal axis. This is an enlarged partial plan view of the cutting surface of the cutting tip of the surgical ultrasonic surgical instrument of Example 1, viewed from the radial direction around the longitudinal axis. This is an enlarged partial cross-sectional view of the cutting surface with the three square pyramids partially cut out at the line xx in Figure 5. This is an enlarged partial cross-sectional view of the vicinity of the cutting surface of the cutting tip of the surgical ultrasonic surgical instrument of Example 2, with a part partially cut out. This is an enlarged partial perspective view of the cutting surface of the cutting tip of the surgical ultrasonic surgical instrument of Example 2, corresponding to the enlarged partial cross-sectional view in Figure 12. This is a partial perspective view showing the cutting part of the cutting tip in Example 3 of the present invention. This is a front view showing the cutting part of the cutting tip in Example 3 of the present invention. This is a partial perspective view showing how a general surgical ultrasonic surgical instrument cutting tip cuts a groove in the area to be treated. This is an enlarged partial cross-sectional view of the cutting tip and the area to be treated with the part partially cut out at the line xx in Figure 15. Figure 15 is an enlarged partial cross-sectional view showing a partial cutout of the cutting tip and the area to be treated along the line xx. This is a schematic perspective view showing the cutting portion of the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 4 of the present invention.This is an enlarged partial cross-sectional view showing how the cutting tip of the ultrasonic surgical instrument of Example 4 cuts grooves into the area to be treated. This is an enlarged partial cross-sectional view showing how the cutting tip of a modified version of the ultrasonic surgical instrument of Example 4 cuts grooves into the area to be treated. This is an enlarged partial cross-sectional view showing how the cutting tip 4 of a second modified version of the ultrasonic surgical instrument of Example 4 cuts grooves into the area to be treated. This is a partial side view showing the cutting part of the ultrasonic surgical instrument cutting tip in Example 5, which has multiple square pyramids around its entire circumference. This is a front view showing the cutting part of the cutting tip of Example 5. This is a partially enlarged front view showing the three square pyramids within the dashed-dotted frame y in Figure 21B. This is a partially enlarged front view showing the three square pyramidal convex-concave tip shape at a part of the tip near the cutting surface of the cutting part of the ultrasonic surgical instrument cutting tip of the first modified version of Example 5. This is a partial side view showing the cutting part of the ultrasonic surgical instrument cutting tip in Example 6, which has multiple square pyramids around its entire circumference. This is a front view showing the cutting part of the ultrasonic surgical instrument cutting tip in Example 6. This is a partially enlarged front view showing three square pyramids within the dashed-dotted frame y of Figure 24B. This is a partially enlarged front view showing the uneven tip shape of three square pyramids in a part of the tip near the cutting surface of the cutting part of the cutting tip of the surgical ultrasonic surgical instrument of the first modified example of Example 6. This is a partially side view showing the cutting part of the ultrasonic surgical instrument cutting tip of Example 7, which has multiple square pyramids around its entire circumference. This is a front view showing the cutting part of the cutting tip of Example 7. This is a partially side view showing the cutting part of the ultrasonic surgical instrument cutting tip of Example 8, which has multiple square pyramids around its entire circumference. This is a front view showing the cutting part of the cutting tip of Example 8. This is an enlarged partially cross-sectional view showing how the cutting part of the surgical ultrasonic surgical instrument cutting tip of Example 4 cuts grooves into the area to be treated. This is an enlarged partially cross-sectional view showing how the cutting part of the surgical ultrasonic surgical instrument cutting tip of Example 9 cuts grooves into the area to be treated. This is an enlarged partially cross-sectional view showing how the cutting part of the surgical ultrasonic surgical instrument cutting tip of Example 9 cuts grooves into the area to be treated. This is a partially cutaway side view showing an internal longitudinal section of the front side of a surgical ultrasonic surgical instrument to illustrate the configuration of the cutting tip of an embodiment of the present invention. This is a partially cut side view showing the cutting section of the cutting tip of Example 10, which has multiple square pyramids only on its lower surface. This is a front view showing the cutting section of the cutting tip of Example 10.This is a schematic perspective view illustrating the general appearance of an ultrasonic surgical instrument, which is Embodiment 11 of the present invention. This is a schematic perspective view showing the cutting portion of the cutting tip of an ultrasonic surgical instrument, which is Embodiment 11 of the present invention. This is a partial plan view of the cutting surface when viewed from above (visually from the radial direction around the axis of the longitudinal axis), illustrating the cutting portion of the cutting tip of an ultrasonic surgical instrument, which is Embodiment 11 of the present invention. This is a schematic perspective view showing a square pyramid formed on the cutting surface of the cutting portion of the cutting tip of an ultrasonic surgical instrument, which is Embodiment 11 of the present invention. This is a partial plan view to explain the compound vibration of the cutting surface, which does not show a square pyramid, when viewed from above (visually from the radial direction around the axis of the longitudinal axis), illustrating the cutting surface of the cutting tip of an ultrasonic surgical instrument, which is a modified example of Embodiment 11 of the present invention. This is a partial plan view of the cutting surface of a conventional ultrasonic surgical instrument's ultrasonic tip, schematically showing the cutting function part of the cutting surface when viewed from above (visually viewed from the radial direction around the longitudinal axis). This is a partial side view showing the ultrasonic tip of a conventional ultrasonic surgical instrument. This is a cross-sectional view along line xx in Figure 10. This is a partial side view showing the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 12 of the present invention. This is a cross-sectional view along line xx in Figure 42. This is an explanatory diagram illustrating parameters for explaining the heat generation of an ultrasonic tip of a general ultrasonic surgical instrument. This is a partial side view showing the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 13 of the present invention. This is a cross-sectional view along line xx in Figure 45. This is a schematic perspective view showing the cutting part of a cutting tip of a surgical ultrasonic surgical instrument, which is a modified example of an embodiment of the present invention. This is a partially cutaway side view showing an internal longitudinal section on the front side of a surgical ultrasonic surgical instrument to show the configuration of the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 14 of the present invention. This is a partially cutaway side view showing an internal longitudinal section on the front side of a surgical ultrasonic surgical instrument to show the configuration of the cutting tip of a surgical ultrasonic surgical instrument, which is a modified example of Embodiment 14 of the present invention. This is a partially cutaway side view showing an internal longitudinal section of the front of a surgical ultrasonic surgical instrument to illustrate the configuration of the cutting tip of a surgical ultrasonic surgical instrument, which is a further modification of Embodiment 14 of the present invention.This is a partial plan view of the cutting surface, schematically showing the cutting portion of the cutting tip of a surgical ultrasonic surgical instrument, which is a modified example of Embodiment 11 of the present invention. This is a partial side view showing the cutting portion of the cutting tip of an ultrasonic surgical instrument, which is equipped with multiple square pyramids around its entire circumference, in a further modified example of Embodiment 11. This is a cross-sectional view of the cutting portion at line xx in Figure 22A. This is a partial plan view of the cutting surface, schematically showing the cutting portion of the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 15 of the present invention, in a plan view. This is a perspective view schematically showing the hexagonal pyramid formed on the cutting surface of the cutting portion of the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 15 of the present invention. This is a partial plan view of the cutting surface, schematically showing the cutting portion of the cutting tip of a surgical ultrasonic surgical instrument, which is Embodiment 16 of the present invention, in a plan view. This is a partial side view showing the cutting portion of the cutting tip of an ultrasonic surgical instrument, which is equipped with multiple hexagonal pyramids around its entire circumference, in a modified example of Embodiment 16. This is a cross-sectional view of the cutting portion at line xx in Figure 26A. This is a schematic partial plan view of the cutting surface of a cutting tip of a surgical ultrasonic surgical instrument, which is a modified example of Embodiment 16 of the present invention, when viewed from above (visually from the radial direction around the longitudinal axis).

[0031] An embodiment of the surgical ultrasonic surgical instrument according to the present invention and its embodiments will be described in detail with reference to the drawings. In the embodiments and examples, components having substantially the same function and configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0032] In the following, the longitudinal axis direction (extension direction of the longitudinal axis LT) of the surgical ultrasonic device is defined as the direction on the paper in the drawings, and the left and right sides of the paper are defined as the back and front, respectively.

[0033] Figure 1 is a schematic perspective view illustrating the general external appearance of a surgical ultrasonic surgical instrument 1, which is an embodiment of the present invention. Figure 2 is a longitudinal cross-sectional view of the surgical ultrasonic surgical instrument 1, illustrating the internal configuration of the surgical ultrasonic surgical instrument 1.

[0034] The surgical ultrasonic device 1 comprises a handle portion 3 in which a transducer that outputs desired ultrasonic vibrations is incorporated, a cutting tip 4 that functions as a vibration transmission member of the trunk extending from the transducer of the handle portion 3, and an intermediate cover 3a and a sheath tube 5 of the cover of the cutting tip 4. The cutting tip 4 has a cutting portion CP at the front end (distal end) of its trunk, and the cutting portion CP is exposed from the front end opening of the sheath tube 5.

[0035] The handle portion 3 is a case that protects the internal transducer 12 from external forces or moisture. The handle portion 3 is also the gripping portion when the user holds the surgical ultrasonic surgical instrument 1. Therefore, it is desirable that the handle portion 3 has a shape that is easy for the user to grip, for example, a shape in which the longitudinal axis LT is bent so that the cutting surface CPF of the cutting portion CP at the front end of the cutting tip 4 faces the rear of the handle portion 3.

[0036] The intermediate cover 3a and sheath tube 5, positioned at the front of the handle portion 3, are configured to cover the cutting tip 4 extending from the handle portion 3, except for the cutting portion CP, via the fluid flow path LP. The intermediate cover 3a and sheath tube 5 prevent contact between the cutting tip 4 and unintended objects (not shown), thereby protecting the cutting tip 4. The sheath tube 5 has a tapered shape that gradually narrows towards the cutting portion CP at the front end of the cutting tip 4.

[0037] A snap-fit ​​structure (FIT) is provided on the front outer circumference of the handle portion 3 and the intermediate cover 3a, and on the rear outer circumference of the sheath tube body 5. This fastens the handle portion 3, the intermediate cover 3a, and the sheath tube body 5 together, integrating them as a single unit. In other words, the sheath tube body 5 covers the intermediate cover 3a and the cutting tip 4, and defines a fluid flow path LP between it and the cutting tip 4.

[0038] As shown in Figure 2, the cutting tip 4 is provided with an irrigation suction passage 4SC that penetrates the interior from the cutting portion CP at its front end to the suction passage 11SC of the vibrator 12. The opening of the suction passage 11SC at the front end of the vibrator 12 and the suction passage 4SC of the cutting tip 4 are formed to be fastened together, for example, by a screw structure SC1, so that they can be inserted in a liquid-tight manner.

[0039] On the side of the handle portion 3, an irrigation supply passage 3DC is provided, which supplies irrigation water along the longitudinal axis, and is connected to the water inlet 9.

[0040] The water inlet 9 of the handle portion 3 communicates with the front end opening of the sheath tube 5 via a fluid flow path LP between it and the inner wall of the sheath tube 5, which is connected to the front end opening of the handle portion 3 and integrated with the intermediate cover 3a. The water inlet 9 is connected to a water supply device (not shown) via a water supply tube (not shown). During surgical procedures, when irrigation water is supplied in the water supply direction illustrated by the white arrow in Figure 2, the sheath tube 5 can supply irrigation water from the supply passage 3DC through the sheath tube void around the cutting portion CP at the front end of the cutting tip 4.

[0041] The irrigation water supplied around the cutting section CP, along with the cutting residue during treatment, is drawn in through the opening of the suction passage 4SC at the cutting section CP at the front end of the cutting tip 4, and is then drawn in through the suction passage 11SC of the vibrator 12 and the suction passage 6SC of the suction tube connecting pipe 6. As a result, the irrigation water and cutting residue are discharged by a suction device (not shown) through a suction tube (not shown) connected to the suction tube connecting pipe 6 (the irrigation water, etc., are discharged in the suction direction illustrated by the black arrow in Figure 2).

[0042] The handle section 3 has a suction tube connection tube 6, an electrical cord 7, and a water inlet 9 located at its rear. The water inlet 9 is for supplying saline solution to the cutting section CP at the front end of the cutting tip 4 through a supply passage 3DC inside the handle section 3 and a fluid flow path LP around the cutting tip 4. The suction tube connection tube 6 is for suctioning and removing cuttings, water, etc., generated when the cutting section CP of the cutting tip 4 cuts tissue from the target area (not shown), such as bone, through a suction passage 4SC inside the cutting tip 4. The suction tube connection tube 6 is made of, for example, SUS304. The water inlet 9 is connected to a water supply device (not shown) that delivers irrigation water such as saline solution via a water inlet tube (not shown). The suction tube connection tube 6 is connected to a suction device (not shown) that discharges irrigation water and cutting residue via a suction tube (not shown).

[0043] The cutting surface CPF of the cutting part CP is a curved surface of a part of a projected cylinder having a rough surface where the user applies a force substantially perpendicular to the cutting surface CPF when cutting a treatment target part (not shown) such as bone. The cutting surface CPF of the partial cylindrical curved surface is a partial protruding surface of a part of the hook-shaped cutting part CP protruding from the center of the longitudinal axis LT, and has a large number of fine pyramids (hereinafter also referred to as protrusions) as the rough surface. The cutting surface CPF of the cutting part CP faces in the radial direction around the axis of the longitudinal axis LT. The cutting surface CPF is configured to enable a composite vibration including torsional vibration around the axis of the longitudinal axis LT, which is converted from longitudinal vibration by the vibration conversion mechanism SHK of the cutting tip 4. Note that the protruding surface (cutting surface CPF) can be not only a partial cylindrical shape but also an overall cylindrical shape or a partial planar shape.

[0044] Inside the handle part 3, the vibrator 12 is housed. The vibrator 12 is composed of a front metal front panel 11, a middle electrostrictive element PZT, and a rear backing plate 13.

[0045] The front end of the front panel 11 of the vibrator 12 and the rear end (proximal end) of the cutting tip 4 are fastened and integrated with each other by a screw structure SC1. The vibrator 12 and the cutting tip 4 are provided with coaxial inner holes penetrating through their respective centers. After they are integrated, a suction passage 11SC for suction is formed, which communicates from the rear of the vibrator 12 to the cutting surface CPF of the cutting part CP of the cutting tip 4.

[0046] A screw structure SC2 is provided between the front part of the handle part 3 and the rear part of the intermediate cover 3a so as to surround the screw structure SC1 of the vibrator 12 and the cutting tip 4. Thereby, the handle part 3 and the intermediate cover 3a are fastened and integrated with each other. The integrated handle part 3 and intermediate cover 3a hold the vibrator 12 while defining a gap SP.

[0047] The vibrator 12 inside the handle portion 3 is held with a gap SP therebetween from the rear end support structure BS at the rear portion annularly provided on the inner wall of the handle portion 3, and the cutting tip 4 is held from the front end support structure FS at the front portion annularly provided on the inner wall of the intermediate cover 3a. The positions of the rear end support structure BS at the rear portion and the front end support structure FS at the front portion are provided at the nodes of the longitudinal vibration of the vibrator 12 and the cutting tip 4 so as not to attenuate the ultrasonic vibration transmitted from the vibrator 12. That is, the vibrator 12 is fixed to the handle portion 3 and the intermediate cover 3a near the position of the node of its longitudinal vibration.

[0048] Further, the electrostrictive element PZT of the vibrator 12 in the handle portion 3 is electrically connected to the electric cord 7 via the wirings 7a and 7b. The electric cord 7 is connected to the control device main body (not shown) of the surgical ultrasonic surgical instrument 1. The user can turn on and off the surgical ultrasonic surgical instrument 1 held in the hand by operating a foot switch (not shown) connected to the control device main body with the foot.

[0049] The electrostrictive element PZT of the vibrator 12 is, for example, an electric element in which cylindrical plates of piezoelectric ceramics such as barium titanate or lead zirconate titanate are laminated and both ends are sandwiched between electrodes. The electrostrictive element PZT outputs desired ultrasonic vibration (longitudinal vibration) to the rear end of the cutting tip 4 by the electrostrictive effect of converting electrical energy supplied by the electric cord 7 into mechanical energy.

[0050] FIG. 3 is a graph for explaining a standing wave corresponding to the ultrasonic vibration generated by the vibrator 12 when the vibrator 12 is electrically controlled via the electric cord 7.

[0051] As shown in FIG. 3, the displacements of the longitudinal vibrations of the vibrator 12 and the cutting tip 4 exhibit nodes at the positions (PN1 and PN2 positions) of the rear end support structure BS and the front end support structure FS that are separated from each other by half the wavelength of the longitudinal vibration, and exhibit an antinode 1 in the abdomen between the rear end support structure BS and the front end support structure FS. Since the displacement of the longitudinal vibration is small at the node portion, the frictional heat between the cutting tip 4 and the front end support structure FS is reduced, so it is preferable to arrange the rear end support structure BS and the front end support structure FS at the node portion.

[0052] Figure 4 is a partially cutaway side view showing an internal longitudinal section of the front side of the surgical ultrasonic surgical instrument 1, illustrating the structure of the cutting tip 4. The cutting tip 4 is formed in a tubular shape from a metal such as titanium or an alloy thereof. The cutting tip 4 functions to transmit the composite vibrations converted from the longitudinal vibrations of the transducer 12 connected at the rear end (proximal end) to the cutting section CP at the front end (distal end).

[0053] The cutting tip 4 is equipped with a vibration conversion mechanism SHK coupled to the transducer 12. The vibration conversion mechanism SHK has a plurality of helical or oblique grooves HK, each formed obliquely to the longitudinal axis LT on the outer surface of the cutting tip 4. The vibration conversion mechanism SHK converts the ultrasonic vibrations transmitted from the transducer 12 into a composite vibration including a longitudinal vibration component in the longitudinal axis direction along the longitudinal axis LT and a torsional vibration component (rotational vibration component) in the torsional direction TW around the axis with the longitudinal axis LT as the central axis. The composite vibration around the axis of the longitudinal axis LT transmitted to the front end of the cutting tip 4 causes the cutting surface CPF to cut the target area such as bone. The cutting tip 4 can be replaced and used according to the type of cutting surface CPF of the cutting part CP corresponding to the target area. The rod of the cutting tip 4 has a tapered shape in which its cross-sectional area gradually decreases from the vibration conversion mechanism SHK toward the cutting part CP at the front end.

[0054] (Example 1) Figure 5 is a schematic perspective view from below to above showing the cutting portion CP of the cutting tip 4 of the surgical ultrasonic surgical instrument 1, which is Example 1. Figure 6 is a partial plan view of the cutting surface CPF of the cutting portion CP of the cutting tip 4 of the surgical ultrasonic surgical instrument 1 when viewed from above (visually viewed from the radial direction around the axis of the longitudinal axis LT). Figure 7 is a schematic enlarged partial plan view of one of the multiple square pyramidal pyramids QRP (hereinafter also simply called pyramidal pyramids) formed on the cutting surface CPF of the cutting portion CP of the cutting tip 4 when viewed from above.

[0055] As shown in Figures 5 and 6, on the cutting surface CPF of the cutting portion CP of the cutting tip 4, multiple square pyramidal QRPs (projections), each with a square base, are arranged in the tightest possible order from the front end, and each square pyramidal QRP has multiple edges (edges that are perpendicular to the projection vertex PP when viewed from above) extending from the projection vertex PP. As shown in Figure 7, each square pyramidal QRP is formed such that the torsional direction TW and the two diagonals extending perpendicularly to it are equal on the base surface of the cutting surface CPF at its base. Therefore, each square pyramidal QRP has four side edges SRD from the projection vertex PP, and for example, the part to be treated (not shown) is cut by the two side edges SRD extending along the torsional direction TW. Note that the square pyramidal QRP may also be a square pyramid, parallelogram pyramid, rhombic pyramid, etc.

[0056] Generally, when performing a cutting operation on a target area (not shown) using the cutting surface CPF of the cutting tip 4 of a surgical ultrasonic device, if there is a large amount of uncut material remaining on the target area due to the projection apex PP of the square pyramidal QRP on the cutting surface, it becomes difficult to smoothly and deeply cut grooves on the target area. Therefore, we investigate the relationship between the uncut material remaining on the target area due to two adjacent square pyramidal QRPs vibrating together on the cutting surface CPF and the trajectory of the projection apex PP of the square pyramidal QRP, and explore conditions to solve this problem.

[0057] Figures 8 to 10 are enlarged plan views of the cutting surface CPF of the cutting tip 4 of the ultrasonic surgical instrument 1, viewed from above (visually from the radial direction around the longitudinal axis LT). As shown in Figures 8 to 10, the cutting range (white double-headed arrows) was investigated based on the trajectory of the projection vertex PP of two adjacent square pyramidal pyramids QRPs on the cutting surface CPF, determined by the amplitude d1 of the combined vibration of the projection vertex PP of two adjacent square pyramidal pyramids QRPs in the torsional direction TW (in the plane perpendicular to the longitudinal axis LT). Here, the distance between the projection vertex PP of two adjacent square pyramidal pyramids QRPs is defined as the projection spacing Ld1.

[0058] First, as shown in Figure 8, when twice the amplitude d1 of the small compound vibration of the protrusion vertices PP of two adjacent square pyramidal QRPs is less than the distance Ld1 between the protrusions (2 × d1 < Ld1), an area ne remains uncut between the two protrusion vertices PP.

[0059] Next, as shown in Figure 9, when twice the amplitude d1 of the enlarged compound vibration becomes equal to the projection spacing Ld1 (2 × d1 = Ld1), the area between the two projection vertices PP disappears.

[0060] Furthermore, as shown in Figure 10, when the amplitude d1 of the even larger compound vibration exceeds twice the projection spacing Ld1 (2 × d1 > Ld1), an area ch is created between the two projection vertices PP where the respective compound vibrations overlap, resulting in no areas remaining uncut.

[0061] Therefore, when Ld1 is the distance between adjacent projection vertices PP of the square pyramid QRP, and d1 is the amplitude of the compound vibration, it is preferable that the cutting surface CPF be formed such that the relationship between the amplitude d1 of the compound vibration and the projection spacing Ld1 satisfies the following equation, 2 × d1 ≥ Ld1, as shown in Figures 9 and 10. Here, the projection spacing Ld1 and the amplitude d1 of the compound vibration are related to the direction of the compound vibration and are distances measured parallel to the vibration direction (tangential direction).

[0062] Furthermore, as shown in Figure 11, the projection tip angle θt is related to the projection spacing Ld1, so a projection tip angle θt of 60 degrees or less is desirable. A smaller projection tip angle θt results in a smaller projection spacing Ld1, making it easier to satisfy the relationship between the amplitude d1 of the compound vibration and the projection spacing Ld1 (2 × d1 ≥ Ld1) in the above equation. If the projection tip angle θt exceeds 60 degrees, the number of square pyramidal QRPs decreases, affecting the cutting efficiency. Figure 11 is an enlarged partial cross-sectional view in which three square pyramidal QRPs of the cutting surface are partially cut out along the line xx in Figure 5.

[0063] According to the surgical ultrasonic device of Embodiment 1 of the present invention, when performing cutting operations on a target area such as bone, it is possible to prevent incomplete removal of the target area and to smoothly and deeply cut grooves in the target area.

[0064] (Example 2) In Example 1, the relationship between the amplitude d1 of the compound vibration and the projection spacing Ld1 is given by (2 × d1 ≥ Ld1). In order to actually satisfy the conditions of this relationship, the projection spacing Ld1 becomes larger when the square pyramidal QRP is made taller. Therefore, the amplitude d1 of the compound vibration must be increased, or the projection tip angle θt of each square pyramidal QRP shown in Figure 11 must be decreased. However, if the amplitude d1 is increased, the stress on the cutting tip 4 will increase proportionally, and there is a risk that the cutting tip 4 will break. Also, if the projection tip angle θt of each square pyramidal QRP is decreased and the projection tip is made taller, the square pyramidal QRP becomes thinner, and there is a possibility that the square pyramidal QRP will break during groove cutting.

[0065] Therefore, in order to solve these problems, as in Example 2, it is effective to have a bumpy tip shape in which valleys VV are provided at the tip (dashed line portion) including the protruding vertex of each square pyramidal QRP, as shown in Figure 12. With this bumpy tip shape of Example 2, the projection spacing Ld1 can be made smaller than in the case without valleys VV (Figure 11), and it is possible to prevent each square pyramidal QRP from becoming thinner. Figure 12 is an enlarged partial cross-sectional view of the cutting surface CPF of the cutting portion CP of the cutting tip 4 of Example 2, with a portion partially cut out. Figure 13 is an enlarged partial perspective view of the cutting surface CPF of the cutting portion CP of the cutting tip 4 of Example 2, corresponding to the enlarged partial cross-sectional view of Figure 12. As shown in Figure 13, the bumpy tip shape of each square pyramidal QRP of the cutting surface CPF has four divided protruding vertices PP2 divided by two valleys VV (two line segments) that intersect at the protruding vertices, and the two valleys VV between the divided protruding vertices PP2.

[0066] Thus, in the ultrasonic surgical instrument for surgical use of Example 2, it is preferable that the multiple square pyramidal QRPs are formed with an uneven tip shape having multiple divided protruding vertices PP2 divided at the tip of the protruding vertex PP, and valleys VV between them. The uneven tip shape of each pyramid makes it possible to reduce the spacing between adjacent pyramids and prevent the tips of each pyramid from becoming too thin. Furthermore, the uneven tip shape with valleys VV at the protruding tips can be provided only in the front row of the multiple square pyramidal QRPs, only in the side row, or in both rows. That is, in addition to the distal end of the cutting surface CPF of the cutting tip 4, at least the tallest square pyramidal QRP 1 among the multiple square pyramidal QRPs has an uneven tip shape (a shape having multiple divided protruding vertices PP2 divided at the tip of the protruding vertex, and valleys VV between them).

[0067] (Example 3) The structure of the cutting portion CP of the ultrasonic surgical instrument 1 of Example 3 is shown in Figures 14A and 14B. Figure 14A shows a partial perspective view of the cutting portion CP of the cutting tip 4 of Example 3. Figure 14B shows a front view of the cutting portion CP of the cutting tip 4 of Example 3. The cutting tip 4 of the ultrasonic surgical instrument of Example 3 is the same as that of Example 2, except that instead of the hook-shaped cutting portion of the cutting tip 4 of Example 2, the cutting portion CP of the cutting tip 4 is cylindrical, as shown in Figures 14A and 14B, with multiple square pyramidal QRPs formed around its circumference, and all of the tip of these protrusions having a convex and concave tip shape with a divided protrusion apex PP2 and a valley VV. With the cutting tip 4 of Example 3, because multiple square pyramidal QRPs are formed around the circumference, more cutting residue from the treatment area can be scraped off on both sides in the pulling direction of the cutting tip 4.

[0068] (Example 4) Generally, when performing a cutting operation on a treatment area using the cutting surface CPF of the cutting tip 4 of a surgical ultrasonic surgical instrument, as shown in Figure 15, the tip of the cutting surface CPF of the cutting part CP of the cutting tip 4 is inserted diagonally into the treatment area, and then, for example, it is pulled in the direction of the white arrow to cut a groove in the treatment area, i.e., groove cutting. Figure 15 is a partial perspective view showing the cutting of a groove in a treatment area using the cutting tip 4 of a surgical ultrasonic surgical instrument.

[0069] Figures 16A and 16B are enlarged cross-sectional views in which the cutting tip 4 and the area to be treated are partially cut out along the line xx in Figure 15. When cutting grooves, as shown in Figure 16A, the tip of the cutting surface CPF of the cutting portion CP of the cutting tip 4 penetrates the area to be treated to a depth from the tip to the bottom of the first row of square pyramidal QRPs V1 (i.e., the height of the first row of square pyramidal QRPs), and a groove can be formed to that depth. However, if the tip of the cutting surface CPF of the cutting portion CP of the cutting tip 4 penetrates the area to be treated deeper than the bottom of the first row of square pyramidal QRPs V1, as shown in Figure 16B, there are no square pyramidal QRPs to cut the area to be treated in the filled portion of the cutting portion CP, making it difficult to cut grooves deeper than the depth to the bottom of the valleys V1. Therefore, as shown in Figure 16A, it is necessary to repeatedly insert the tip shallowly into the area to be treated and pull it back to dig a shallow groove.

[0070] Therefore, in the cutting tip 4 of the ultrasonic surgical instrument of Example 4, as shown in Figure 17, the multiple square pyramidal QRPs are formed such that, for example, the first row of square pyramidal QRPs 1 is higher than the subsequent ones, up to at least the second row from the tip of the cutting surface CPF of the cutting section CP. The cutting tip 4 of the ultrasonic surgical instrument of Example 4 is the same as that of Example 1, except that the first row of square pyramidal QRPs 1 is formed higher than the subsequent square pyramidal QRPs. Figure 17 is a schematic perspective view showing the cutting surface CPF of the cutting section CP of the cutting tip 4 of the ultrasonic surgical instrument of Example 4. That is, as shown in Figure 18, the cutting tip 4 of Example 4 has a cutting surface CPF that includes a tall square pyramidal QRP 1 and subsequent square pyramidal QRPs of lower height. Figure 18 is an enlarged partial cross-sectional view showing how the cutting tip 4 of the modified ultrasonic surgical instrument of Example 4 cuts a groove in the area to be treated.

[0071] Thus, as shown in Figure 18, with the cutting tip 4 of Embodiment 4, by making the first row of square pyramidal QRPs higher than the subsequent ones, for example, up to the second row from the tip of the cutting surface CPF of the cutting section CP, the groove of the target area can be cut deeper in one go, making it possible to cut grooves of the required depth with fewer operations. Therefore, when the torsional vibration in the combined vibration, which is a mix of longitudinal vibration and torsional vibration of the cutting tip 4, vibrates at the same twist angle in the square pyramidal QRP1 and QRP, the amplitude of the combined vibration is larger at the projection vertex PP of the taller square pyramidal QRP1 (further from the axis center of the longitudinal axis LT) than at the lower square pyramidal QRP, thus increasing the cutting force at the tip of the cutting tip 4. Furthermore, the taller square pyramidal QRP1 and the lower square pyramidal QRP may each consist of at least one row or more.

[0072] Comparing Figure 18 and Figure 16A, it can be seen that the cutting tip 4 of this embodiment 4 can cut deeper grooves in a single operation than that of embodiment 2. As can be seen from the comparison between Figure 18 and Figure 16A, it can be confirmed that groove cutting can be performed more efficiently with the cutting tip 4 of embodiment 4.

[0073] (First Modification of Example 4) Figure 19 is an enlarged partial cross-sectional view showing how the cutting tip 4 of the first modification of the surgical ultrasonic device of Example 4 cuts grooves into the area to be treated. As shown in Figure 19, the height of the square pyramidal QRP of the cutting tip 4 gradually decreases from the square pyramidal QRP 1 at the tip. That is, the first modification of Example 4 is the same as Example 2 except that the multiple square pyramidal QRPs are formed so that their height gradually decreases sequentially from the highest point at the tip of the cutting surface CPF of the cutting section CP toward the rear end of the cutting tip 4. As a result, grooves can be cut while pulling on even more parts of the area to be treated by the square pyramidal QRPs whose height gradually decreases from the square pyramidal QRP 1 at the tip.

[0074] (Second Modification of Example 4) Figure 20 is an enlarged partial cross-sectional view showing how the cutting tip 4 of the second modification of the ultrasonic surgical instrument for surgical use in Example 4 cuts a groove in the area to be treated. As shown in Figure 20, the cross section including the center line of all or part of the square pyramidal QRP of the cutting tip 4 is curved, that is, in Figure 20, the side surface on the near end (handle part) side of the square pyramidal QRP 1 at the tip is a concave curved surface KM. In other words, the second modification of Example 4 is the same as Example 2 except that the multiple square pyramidal QRPs are formed so that the side surface on the near end (handle part) side of the square pyramidal QRP 1 at the tip of the cutting surface CPF of the cutting section CP is a concave curved surface KM. In other words, in the second modification of Example 4, the tallest square pyramidal QRP 1 at the tip of the cutting surface CPF of the cutting section CP is formed thinly with a concave curved surface KM on the side toward the rear end of the cutting tip 4. In the second modification of Example 4, the concave curved surface KM thins the area near the tip of the protrusion of the tall square pyramid QRP1, which has a protrusion tip that is far from the center of the longitudinal axis LT, thus providing the effect of further increasing the cutting force.

[0075] (Example 5) Next, Example 5 is shown in Figures 21A, 21B and 22. Figure 21A is a partial side view showing the cutting section CP of the cutting tip 4 of the ultrasonic surgical instrument in Example 5, which has multiple square pyramidal QRPs around its entire circumference. Figure 21B is a front view of the cutting section CP of the cutting tip 4 of Example 5. Figure 22 is a partially enlarged front view showing the three square pyramidal QRPs 1 within the dashed-dotted frame y of Figure 21B.

[0076] The ultrasonic surgical instrument of Example 5 is identical to that of Example 2, except that, as shown in Figures 21A, 21B, and 22, the cutting portion CP of the cutting tip 4 is cylindrical instead of hook-shaped, and multiple low square pyramidal QRPs and multiple high square pyramidal QRPs 1 in the first row of the frontmost column are formed as the cutting surface CPF along its circumference, arranged spirally around the longitudinal axis LT.

[0077] With the surgical ultrasonic device of Example 5, the tall square pyramidal QRP1 in the first row allows for deep groove cutting of the treatment area in one go, and further cutting residue from the treatment area can be scraped out on both sides in the direction of the pulling of the cutting tip 4, thus enabling groove cutting to the required depth. Thus, according to Example 5, groove cutting can be facilitated by the square pyramidal QRP around the entire circumference and the tall square pyramidal QRP1.

[0078] (First Modification of Example 5) In the case of the ultrasonic surgical instrument for surgical use of Example 5 shown in Figure 22, in order to improve the efficiency of groove cutting, the projection spacing Ld1 becomes larger when each of the square pyramids QRP1 is made taller, so the amplitude of the compound vibration must be increased, or the projection tip angle θt of each square pyramid QRP1 shown in Figure 22 must be decreased. However, as the amplitude of the compound vibration increases, the stress on the cutting tip 4 increases, and there is a risk that the cutting tip 4 will break. Also, if the projection tip angle θt of each square pyramid QRP1 is decreased and the projection apex PP is made taller, the square pyramid QRP1 becomes thinner, so there is a possibility that the square pyramid QRP1 will break during groove cutting.

[0079] Therefore, the first modification of Example 5 is the same as Example 5, except that, as shown in Figure 23, a groove VV is provided instead of the tip (the portion indicated by the dashed line) containing the protruding vertices of each of the multiple square pyramidal QRP1, resulting in an uneven tip shape. Figure 23 is a partially enlarged front view showing the uneven tip shape of three tall square pyramidal QRP1 in a part of the tip near the cutting surface CPF of the cutting portion CP of the cutting tip 4 of Example 5. With this uneven tip shape of the first modification of Example 5, the spacing between adjacent protruding vertices PP can be made smaller than in the case without groove VV (Figure 22), and it is possible to prevent each square pyramidal QRP1 from becoming thinner. The uneven tip shape of each square pyramidal QRP1 on the cutting surface CPF is the same as the uneven tip shape of Example 2 shown in Figure 13, having four divided protruding vertices PP2 divided by two groove VV (two line segments) that intersect at the protruding vertices, and the two groove VV between the divided protruding vertices PP2.

[0080] (Example 6) Next, Example 6 is shown in Figures 24A, 24B and 25. Figure 24A is a partial side view showing the cutting section CP of the cutting tip 4 of the ultrasonic surgical instrument in Example 6, which has multiple square pyramidal QRPs around its entire circumference. Figure 24B is a front view of the cutting section CP of the cutting tip 4 of Example 6. Figure 25 is a partially enlarged front view showing the three square pyramidal QRPs 1 within the dashed-dotted frame y of Figure 24B.

[0081] The surgical ultrasonic surgical instrument of Example 6 is identical to that of Example 2, except that, as shown in Figures 24A, 24B, and 25, the cutting portion CP of the cutting tip 4 is cylindrical instead of hook-shaped, and the cutting surface CPF is formed by a plurality of low square pyramidal QRPs arranged spirally along the longitudinal axis LT around its entire circumference, and a pyramidal first row of multiple high square pyramidal QRPs 1 in the front row, with their sides facing the direction of the compound vibration rather than spirally. In other words, the surgical ultrasonic surgical instrument of Example 6 is identical to that of Example 5, except that the edges of each of the high square pyramidal QRPs 1 intersect diagonally with respect to the direction of the compound vibration.

[0082] With the surgical ultrasonic device of Example 6, the tall square pyramidal QRP1 in the first row allows for deep groove cutting of the treatment area in one go, and further scraping of cutting residue from the treatment area can be removed on both sides in the pulling direction of the cutting tip 4, thus enabling groove cutting to the required depth. Thus, according to Example 6, groove cutting can be facilitated by the square pyramidal QRP around the entire circumference and the tall square pyramidal QRP1.

[0083] (First Modification of Example 6) In the case of the ultrasonic surgical instrument for surgical use of Example 6 shown in Figure 25, in order to improve the efficiency of groove cutting, the projection spacing Ld1 becomes larger when each of the square pyramids QRP1 is made taller, so the amplitude of the compound vibration must be increased, or the projection tip angle θt of each square pyramid QRP1 shown in Figure 25 must be decreased. However, as the amplitude of the compound vibration increases, the stress on the cutting tip 4 increases, and there is a risk that the cutting tip 4 will break. Also, if the projection tip angle θt of each square pyramid QRP1 is decreased and the projection apex PP is made taller, the square pyramid QRP1 becomes thinner, so there is a possibility that the square pyramid QRP1 will break during groove cutting.

[0084] Therefore, the first modification of Example 6 is the same as Example 6, except that, as shown in Figure 26, a groove VV is provided instead of the tip (the portion indicated by the dashed line) containing the vertices of each of the multiple square pyramidal QRP1, resulting in an uneven tip shape. Figure 26 is a partially enlarged front view showing the uneven tip shape of three tall square pyramidal QRP1 in a part of the tip near the cutting surface CPF of the cutting portion CP of the cutting tip 4 of Example 6. With this uneven tip shape of the first modification of Example 6, the spacing between adjacent vertices PP can be made smaller than in the case without groove VV (Figure 25), and it is possible to prevent each square pyramidal QRP1 from becoming thinner. The uneven tip shape of each square pyramidal QRP1 on the cutting surface CPF is the same as the uneven tip shape of Example 2 shown in Figure 13, having four divided vertices PP2 divided by two grooves VV (two line segments) that intersect at the vertices of the vertices, and the two grooves VV between the divided vertices PP2.

[0085] (Example 7) Next, Example 7 is shown in Figures 27A and 27B. Figure 27A is a partial side view showing the cutting section CP of the cutting tip 4 of the ultrasonic surgical instrument in Example 7, which has multiple square pyramidal QRPs around its entire circumference. Figure 27B is a front view of the cutting section CP of the cutting tip 4 in Example 7.

[0086] The surgical ultrasonic device of Example 7 is identical to that of Example 2, except that, as shown in Figures 27A and 27B, the cutting portion CP of the cutting tip 4 is cylindrical instead of hook-shaped, and multiple low square pyramidal QRPs and multiple high square pyramidal QRP1 in the first row of the front row are formed as the cutting surface CPF around its circumference so that each side is aligned parallel to the longitudinal axis LT. In other words, the surgical ultrasonic device of Example 7 is identical to that of Example 6, except that the edges of all the square pyramidal QRPs and QRP1 intersect obliquely with respect to the direction of combined vibration.

[0087] With the ultrasonic surgical instrument of Example 7, the tall square pyramidal QRP1 in the first row allows for deep groove cutting of the treatment area in one go, and further cutting residue from the treatment area can be scraped out on both sides in the pulling direction of the cutting tip 4, thus enabling groove cutting to the required depth. Thus, according to Example 7, groove cutting can be facilitated by the square pyramidal QRP around the entire circumference and the tall square pyramidal QRP1.

[0088] (Example 8) Next, Example 8 is shown in Figures 28A and 28B. Figure 28A is a partial side view showing the cutting section CP of the cutting tip 4 of the ultrasonic surgical instrument in Example 8, which has multiple square pyramidal QRPs around its entire circumference. Figure 28B is a front view of the cutting section CP of the cutting tip 4 in Example 8.

[0089] The surgical ultrasonic device of Example 8 is identical to that of Example 2, except that, as shown in Figures 28A and 28B, the cutting portion CP of the cutting tip 4 is cylindrical instead of hook-shaped, the multiple low square pyramidal QRPs are aligned so that their respective sides are parallel to the longitudinal axis LT, and the multiple high square pyramidal QRPs 1 in the front row are formed so that their respective edges are aligned perpendicular to and parallel to the longitudinal axis LT. In other words, the surgical ultrasonic device of Example 8 is identical to that of Example 7, except that the edges of the high square pyramidal QRPs 1 in the front row are aligned along the direction of compound vibration.

[0090] With the surgical ultrasonic device of Example 8, the tall square pyramidal QRP1 in the first row allows for deep groove cutting of the treatment area in one go, and further scraping of cutting residue from the treatment area can be removed on both sides in the pulling direction of the cutting tip 4, thus enabling groove cutting to the required depth. In this way, according to Example 8, groove cutting can be facilitated by the square pyramidal QRP around the entire circumference and the tall square pyramidal QRP1.

[0091] In addition, in the above-mentioned embodiments 7 and 8, similar to the first modified example of embodiment 5 shown in Figure 23 and the first modified example of embodiment 6 shown in Figure 26 (embodiment 2 shown in Figure 13), the uneven tip shape of each square pyramidal QRP1 of the cutting surface CPF can be configured to have four divided protrusion vertices PP2 divided by two valleys VV (two line segments) that intersect at the protrusion vertices, and the two valleys VV between the divided protrusion vertices PP2, similar to the uneven tip shape of embodiment 2 shown in Figure 13.

[0092] (Example 9) Next, as shown in Figure 29, when performing a cutting operation using the surgical ultrasonic device of Example 4, pushing the cutting tip 4, exemplified by the white arrow, forward, the tall square pyramidal QRP 1 will cut both shallow and deep portions at once, resulting in a large cutting resistance on the front surface of the square pyramidal QRP 1 at the most distal end of the cutting tip 4. Therefore, the cutting resistance on the tip of the square pyramidal QRP 1 becomes large, making smooth operation difficult and potentially causing it to get stuck. Figure 29 is an enlarged cross-sectional view showing how the cutting portion CP of the cutting tip 4 of the surgical ultrasonic device of Example 4 cuts a groove in the area to be treated.

[0093] Therefore, as in Example 9, as shown in Figure 30, when cutting grooves in the pushing direction (white arrow), it is effective to place a lower square pyramidal QRP in front of the taller square pyramidal QRP at the tip. In this case, as shown in Figure 31, it is important to make the groove V2 of the first row of the taller square pyramidal QRP deeper than the groove V1 forming the lower square pyramidal QRP (closer to the longitudinal axis LT), rather than having the groove V1 of the first row of the taller square pyramidal QRP the same as the groove of the subsequent lower square pyramidal QRP, as shown in Figure 30. This is because if the groove V1 of the first row of the taller square pyramidal QRP is the same as that of the lower square pyramidal QRP, the cutting operation will be shallower by H (see Figure 30).

[0094] In other words, in Example 9, as shown in Figure 31, the cutting surface CPF includes a leading square pyramidal QRP that is lower than the lower square pyramidal QRP in the first row at the very front of the cutting tip 4, and a valley bottom V2 deeper than the valley VV between the lower square pyramidal QRPs is formed between the leading square pyramidal QRP and the tallest square pyramidal QRPPT in the second row from the very front of the cutting tip 4. As a result, the leading lower square pyramidal QRP cuts the shallower portion first, which reduces the amount that the taller square pyramidal QRP1 cuts, allowing for a smoother cutting operation with less snagging.

[0095] Furthermore, the uneven edge shape, which has a leading square pyramidal QRP at the tip of the projection, a deep valley V2, and the highest square pyramidal QRPT, can be provided not only in the front row of multiple square pyramidal QRPs at the distal end of the cutting surface CPF of the cutting tip 4, but also, although not shown, in the side row only, or in both rows. By combining these two shapes, smooth and deep groove cutting operations can be performed on the target area without snagging, regardless of whether the operation is performed in the left or right direction.

[0096] (Example 10) Next, as shown in Figure 32, in the hook shape of the cutting portion CP of the cutting tip 4 of the ultrasonic surgical instrument 1, the cutting surface CPF that protrudes far from the longitudinal axis LT and the back surface on the opposite side of the cutting surface CPF are set to be asymmetrical with respect to the longitudinal axis LT (that is, a is the distance of protrusion between the cutting surface CPF and the central axis of the longitudinal axis LT, and b is the distance between the back surface of the cutting portion CP on the opposite side of the cutting surface CPF and the central axis 23, and a is set to > b). Therefore, the volume of the cutting portion CP in the part of the cutting surface CPF that is far from the longitudinal axis LT becomes large, and when the cutting tip 4 is subjected to torsional vibration, the upper and lower balance of the cutting portion CP is disrupted, and deflection vibration may occur throughout the entire cutting tip 4. This deflection vibration can destabilize the vibration and pose a risk of causing a large power loss. Figure 32 is a partially cutaway side view showing an internal longitudinal section of the front side of a surgical ultrasonic surgical instrument, illustrating the configuration of the cutting tip 4 of the surgical ultrasonic surgical instrument in an embodiment similar to that of Figure 4.

[0097] To solve this problem, the structure of the cutting section CP of the ultrasonic surgical instrument 1 of Example 10 is shown in Figures 33A and 33B. Figure 33A is a partial side view showing the cutting section CP of the cutting tip 4 of Example 10, which has multiple square pyramidal QRPs and QRP1 only on the lower surface (one side portion). Figure 33B is a front view showing the cutting section CP of the cutting tip 4 of Example 10. In the ultrasonic surgical instrument 1 of Example 10, in the hook-shaped cutting tip 4 which includes torsional vibration, instead of raising the base only on the square pyramidal QRP side (part a shown in Figure 32), the diameter of the base of the square pyramidal QRP (cylindrical portion DD centered on the longitudinal axis LT) is increased.

[0098] In other words, as shown in Figures 33A and 33B, in this embodiment, there is no part a shown in Figure 32, and the cylindrical part DD becomes the main body of the cutting tip 4, so the only parts that affect the deflection vibration are the square pyramid QRP and QRP1. That is, the cutting part CP of Embodiment 10 has a cylindrical part DD that is coaxial with the main body of the cutting tip 4, has a diameter larger than the diameter of the main body, and supports the cutting surface CPF, and the cutting surface CPF is set as shown in Figure 33B, where TL1 is the distance between the projection vertices PP of the furthest square pyramid QRPs in the direction perpendicular to the longitudinal axis LT among the multiple square pyramid QRPs, and TL2 is the diameter of the cylindrical part DD, so that the following condition is satisfied: TL1 ≥ TL2.

[0099] The ultrasonic surgical instrument of Example 10 has the effect of preventing the generation of deflection vibration of the cutting tip 4.

[0100] (Example 11) Examples 11 to 16 as further embodiments will be described below. First, the structure of the cutting tip 4 of the surgical ultrasonic surgical instrument 1 of Example 11 is shown in Figures 34 to 37. Figure 34 is a schematic perspective view illustrating the general appearance of the surgical ultrasonic surgical instrument 1, which is Example 11 of the present invention. Figure 35 is a schematic perspective view showing the cutting portion CP of the cutting tip 4 of the surgical ultrasonic surgical instrument 1, which is Example 11. Figure 36 is a partial plan view of the cutting surface CPF when the cutting portion CP of the cutting tip 4 of the surgical ultrasonic surgical instrument 1 is viewed from above (viewed from the radial direction around the axis of the longitudinal axis LT). As shown in Figures 35 and 36, the cutting surface CPF of the cutting portion CP of the cutting tip 4 is composed of multiple square pyramidal QRP protrusions, each having multiple ridges (ridges that are perpendicular at the projection vertex PP when viewed from above). Figure 37 is a schematic perspective view showing one of several square pyramidal QRPs formed on the cutting surface CPF of the cutting portion CP of the cutting tip 4. As shown in Figure 37, each square pyramidal QRP is formed such that the two diagonal lines DGL extending in the torsional direction TW are longer than the diagonal lines on the bottom surface of the cutting surface CPF. Therefore, each square pyramidal QRP is a blade-like projection with two gentle side edges SRD1 (first side edges) corresponding to its longer diagonal line DGL extending along the torsional direction TW. This projection is thinner on the side of the side ridge SRD2 (second side ridge), which is steeper than the side ridge SRD1 corresponding to the remaining two diagonals intersecting the torsional direction TW. Therefore, the blade-like projection sharply cuts the target area (not shown) with the blade-like tip KS (projection apex) formed by the two gentle side ridges SRD1. The square pyramidal QRP of the blade-like projection may also be a square pyramid, a parallelogram pyramid, a rhombic pyramid, etc. Thus, each of the multiple square pyramidal QRPs has a blade-like tip KS, and each square pyramidal QRP has two first side ridges SRD1 that extend from the blade-like tip KS inclined in the direction of the longitudinal axis LT from the torsional direction TW, and a second side ridge SRD2 that intersects the first side ridge SRD1 more steeply than the first side ridge SRD1 at the blade-like tip KS.

[0101] Furthermore, modified examples of Example 11 are shown in Figures 38A and 38B. Figure 38A is a partial plan view illustrating the compound vibration of the cutting surface, which does not show a square pyramid, when the cutting portion CP of the cutting tip 4 of the modified ultrasonic surgical instrument 1 is viewed from above (visually from the radial direction around the axis of the longitudinal axis LT). Figure 38B is a partial plan view of the cutting surface CPF showing a square pyramid when the cutting portion CP of the modified example of Figure 38A is viewed from above from the radial direction around the axis of the longitudinal axis LT. The vibration conversion mechanism SHK generates a compound vibration in the cutting portion CP at the tip of the cutting tip 4, which is a combination of longitudinal vibration and torsional vibration. As shown in Figure 38A, the cutting surface CPF vibrates in a compound vibration, tracing a diagonal straight line trajectory CJ (bidirectional arrow) with respect to the longitudinal axis LT. The diagonal straight line trajectory CJ with respect to the longitudinal axis LT intersects the torsional direction TW at an angle φ. Therefore, as shown in Figure 38B, when a plurality of square pyramidal pyramids QRPs, each having a side edge SRD and arranged in a spiral on the cutting surface CPF, are formed in a spiral arrangement of parallelogram pyramids and rhombic pyramids having long and short diagonals, each of the square pyramidal pyramids QRPs is formed such that, when the cutting surface CPF is viewed from above, the longer of the two diagonals, DGL, extends at an angle φ from the twist direction TW in the direction of the longitudinal axis LT (i.e., extends along a diagonal straight line trajectory CJ relative to the longitudinal axis LT). As a result, the two side edges SRDs corresponding to the longer diagonal DGL of the plurality of square pyramidal pyramids QRPs can sharply cut the area to be treated (not shown). In other words, as shown in Figure 38B, the cutting surface CPF is formed by aligning multiple square pyramidal QRPs in a way that the angle (projection angle φ) between the two long side edges SRD of the square pyramidal QRP and the torsional direction TW is within a range (0 ≤ φ < 90 degrees) where it is smaller than 90 degrees (longitudinal axis LT). Note that the cutting surface CPF of Example 11 can also be applied to the cutting portion at the distal end of a non-tubular cutting tip, although not shown.

[0102] By making the projection angle smaller than 90 degrees and aligning the direction of the square pyramidal QRP with the direction of the combined vibration, cutting resistance can be reduced. Furthermore, the embodiment in which the projection angle is 60 degrees or less (0 ≤ φ ≤ 60 degrees) is desirable because it has a greater effect in reducing cutting resistance.

[0103] A comparative experiment was conducted between a conventional ultrasonic surgical instrument and the embodiment. As a conventional ultrasonic surgical instrument, an ultrasonic tip was prepared, as shown in Figure 39, which has a cutting surface 64 with multiple teeth, each tooth 65 having a pyramidal projection, and the sides of each tooth 65 facing in the twisting direction TW. As a result of the comparative experiment between the conventional ultrasonic surgical instrument and the embodiment, it was found that the cutting tip 4 with a cutting surface CPF (cutting portion CP) as shown in Figure 36, as in embodiment 11, reduced cutting resistance more effectively than the conventional ultrasonic tip with a cutting surface 64 of pyramidal projections as shown in Figure 39. According to this embodiment, since cutting resistance can be reduced, cutting efficiency can be increased and overall heat generation of the cutting tip can be suppressed.

[0104] (Example 12) Figure 40 shows a partial side view of the ultrasonic tip 4A of a conventional ultrasonic surgical instrument. Generally, in order to increase the amplitude of the torsional vibration of the cutting function part 62 at the front end of the ultrasonic tip 4A, the amplitude was increased by reducing the polar moment of inertia of the tapered part (part A of the ultrasonic tip 4A) leading to the cutting function part 62, that is, conventionally by making the diameter of the ultrasonic tip 4A smaller. However, when cutting a target area such as bone with a conventional ultrasonic surgical instrument, the user applies force perpendicular to the cutting surface 64 of the cutting function part 62. Therefore, if the diameter of the ultrasonic tip 4A is reduced, part A of the ultrasonic tip 4A bends to the opposite side of the target area, as shown by the dashed line in Figure 40, which adversely affects the combined vibration state and can cause the ultrasonic tip 4A itself to break. It was found that "reducing the diameter of the ultrasonic tip 4A (the diameter exceeding the hollow hole in the cross-section shown in Figure 41)" and "reducing the bending of the ultrasonic tip 4A" are contradictory.

[0105] Therefore, in Example 12, as shown in Figure 42, this conflicting problem is solved by keeping the diameter of the cutting tip 4 the same and cutting the sides in parallel. In Example 12, as shown in Figure 43, the cutting tip 4 has a thin-walled portion TT which is thinner than the other parts and is positioned opposite to the cutting tip 4 in a direction intersecting the twisting direction TW of the cutting tip 4. The other parts are positioned opposite to the user in the direction in which force is applied perpendicular to the cutting surface CPF of the cutting part CP, and are thick-walled portions HT which are thicker than the thin-walled portion TT, extending from the hollow part (suction passage 4SC) of the tubular cutting tip 4, thereby reducing the bending of the cutting tip 4. The thin-walled portion TT is positioned opposite to the cutting tip 4 so as to extend along the radial direction of the cutting tip 4 facing the cutting surface CPF and along the longitudinal axis LT of the cutting tip 4. The thin-walled portion TT is positioned opposite to the user in a direction that intersects with the direction in which the user applies force perpendicular to the cutting surface CPF of the cutting portion CP, and is the portion of the cutting tip 4 that is thinner than the thick-walled portion HT, from the hollow portion (suction passage 4SC) to reduce the polar moment of inertia of the area of ​​the tapered portion (the trunk of portion A shown in Figure 40).

[0106] The thin-walled portion TT is formed by cutting the side surface of the cutting tip 4. The thin-walled portion TT and the thick-walled portion HT reduce the polar moment of inertia of the cutting tip 4 while suppressing the bending of the cutting tip 4. Therefore, the decrease in the polar moment of inertia in the direction in which the user applies force perpendicular to the cutting surface CPF of the cutting portion CP is suppressed.

[0107] Simultaneously, in Example 12, regarding the torsional vibration of the cutting portion CP (cutting surface CPF) at the front end of the cutting tip 4, even with the same twist angle, the further away from the central axis (longitudinal axis LT), the greater the torsional amplitude of the cutting surface CPF. Regarding the torsional vibration of the cutting surface CPF, even with the same twist angle at the same height from the longitudinal axis LT of the cutting surface CPF, the amplitude is greater when it is further away from the longitudinal axis LT. However, if the cutting surface height CPFh of the cutting surface CPF shown in Figure 42 is made too large, vertical vibration occurs, the balance is disrupted, and the vibration becomes unstable. This is related to the second moment of area in the vertical direction of the cutting tip 4, and if the cutting tip 4 is made thin as in the conventional method, the second moment of area in the vertical direction becomes smaller, resulting in vertical vibration. In contrast, by cutting the side surface of the cutting tip 4 of the present invention, the second moment of area in the vertical direction of the cutting tip 4 is large, which suppresses vertical vibration and makes it possible to increase the cutting surface height CPFh. As a result, the tip shape (cutting surface CPF) is farther away from the longitudinal axis LT, resulting in a large cutting surface height CPFh, which increases the torsional amplitude. Thus, according to this embodiment, it is possible to improve cutting efficiency while maintaining the strength of the cutting tip.

[0108] (Further Effects of Example 12) The heat generated by torsion in a typical ultrasonic tip 4A is related to the stress applied to the ultrasonic tip 4A during vibration. The parameters shown in Figure 44 explain that higher stress leads to greater heat generation in the ultrasonic tip 4A. The stress σ of torsional vibration is expressed by the following equation: σ = rGdθ / dx G: Shear modulus of the ultrasonic tip 4A, r: Radius of the ultrasonic tip 4A, dθ: Torsion angle of a minute portion of the ultrasonic tip 4A, dx: Minute portion in the longitudinal axis LT direction. Reducing the radius r of the ultrasonic tip 4A increases the stress σ and thus increases heat generation. Therefore, by cutting the side surface of the cutting tip 4 in Example 12 (thin-walled portion TT), the torsional amplitude of the cutting surface CPF can be increased without reducing the radius r of the thick-walled portion HT of the cutting tip 4 or increasing the torsional angle dθ of the minute portion. In other words, according to Example 12, since there is no side portion of the cutting tip 4 that would normally generate heat (the side-cut portion B shown in Figure 43), the overall heat generation of the cutting tip 4 is kept low.

[0109] (Example 13) The main purposes of flowing irrigation water (physiological saline) into the gap between the cutting tip 4 and the sheath tube 5 are as follows: First, to send irrigation water to the front end of the cutting tip 4 and suppress the heat generated by the bone when the bone treatment target area (not shown) is cut with ultrasonic vibration (heat generated when the cutting tip 4 rubs against the bone). Second, the irrigation water cools the heat generated by the cutting tip 4 due to vibration stress.

[0110] Conventionally, if the flow rate of irrigation water to the front end of the cutting tip 4 is too high, the cutting area CP of the treatment area (surgical area) becomes invisible, so it is necessary to reduce the flow rate of irrigation water. Therefore, a secondary channel (through hole) for the irrigation water is opened on the side of the cutting tip 4, and a portion of the irrigation water is drawn in through this secondary channel (through hole).

[0111] However, due to the stress generated by vibration, if the thickness of the cutting tip 4 with the sub-channels (through holes) is small, cracks may form in the cutting tip 4 from the sub-channels (through holes), which could lead to damage to the cutting tip 4.

[0112] Therefore, in Example 13, in order to prevent such cracking, a sub-channel is opened in the portion of the cutting tip 4 where the diameter remains the same and the side surface is not cut parallel (thick-walled portion HT). In other words, in Example 13, the cutting tip 4 shown in the partial side view of Figure 45 and the cross-sectional view of Figure 46 has a sub-channel, a through-hole HTP in the thick-walled portion, that penetrates from its hollow portion (suction passage 4SC) through the thick-walled portion HT, which is thicker than the thin-walled portion TT, to the outside of the cutting tip 4. By opening this sub-channel in the thick-walled portion HT of the cutting tip 4, the occurrence of cracks caused by the sub-channel can be prevented. Furthermore, by positioning the sub-channel near the antinode of the torsional vibration propagating with respect to the LT axis, the stress near the sub-channel can be suppressed, thereby further preventing the occurrence of cracks. Note that in Figure 46, the through-hole HTP is provided on the upper side of the suction passage 4SC, but it may also be provided on the lower side. It may also be provided on both the upper and lower sides, in which case the upper and lower through-hole positions will be located at antinodes of different torsional vibrations. In Examples 11 to 13, the portion where the side is cut parallel extends to the cutting portion CP at the very front of the cutting tip 4. However, the side cut portion (thin-walled portion TT) may not be provided at the cutting portion CP, as shown in Figure 47. The side cut portion (thin-walled portion TT) may be provided only partially on the tubular portion of the cutting tip 4.

[0113] (Example 14) In the prior art, the angled groove HK of the vibration conversion mechanism SHK of the cutting tip 4 is generally exposed to irrigating water. Therefore, if irrigating water enters the angled groove HK of the vibration conversion mechanism SHK of the cutting tip 4, the vibration of the angled groove HK may cause damage to the angled groove HK and unnecessary power consumption in the angled groove HK.

[0114] Therefore, in Example 14, a structure is provided to prevent perfusion water from entering the oblique groove HK of the cutting tip 4, i.e., a sealing mechanism ST is provided. As shown in Figure 48, the sealing mechanism ST has an annular structure that extends further from the front end support structure FS of the vibrator 12 to the front end in the fluid flow path LP inside the sheath tube 5, covers the vibration conversion mechanism SHK, and is sealed on the cutting tip 4 by an O-ring 10. In this way, the sealing mechanism ST liquid-tightly seals the vibration conversion mechanism SHK from the fluid flow path LP. Furthermore, in a modified example of Example 14, as shown in Figure 49, the O-ring 10 for sealing the annular sealing mechanism ST is made part of the front end support structure of the vibrator 12.

[0115] In Example 14, the position of the sealing O-ring in the sealing mechanism ST is near the node of the torsional vibration. The cutting tip 4, which has an oblique groove HK (vibration conversion mechanism SHK), is sealed by the O-ring 10 near the node of the torsional vibration because the longitudinal vibration transmitted from the vibrator 12 is converted into torsional vibration when it passes through the oblique groove HK. The node of the torsional vibration has a small displacement of torsional vibration and therefore generates less frictional heat with the cutting tip 4, so it is desirable that the position of the O-ring 10 be near the node of the torsional vibration. In a further modification of Example 14, as shown in Figure 50, the annular sealing mechanism ST is extended further forward than in the above modification, and the sealing O-ring 10 is made part of the front end support structure of the vibrator 12. In this case, as shown in the lower part of Figure 50, the position of the O-ring 10 is preferably set near the node 3 of the torsional vibration.

[0116] According to Example 14, by preventing irrigation water from entering the inclined groove HK of the vibration conversion mechanism SHK of the cutting tip 4, the risk of damage to the inclined groove HK due to vibration of the inclined groove HK and the unnecessary power consumption in the inclined groove HK are eliminated.

[0117] (Further Modifications of Example 11) Further modifications of Example 11 are shown in Figures 51, 52A, and 52B. Figure 51 is a partial plan view of the cutting surface CPF of a surgical ultrasonic cutting tip, which is a modification of Example 11, when viewed from above (visually from the radial direction around the longitudinal axis). Figure 52A is a partial side view showing the cutting portion CP of the ultrasonic cutting tip 4 of a further modification of Example 11, which has a plurality of square pyramidal QRPs around its entire circumference. Figure 52B is a cross-sectional view of the cutting portion CP along line xx in Figure 52A.

[0118] In the surgical ultrasonic surgical instrument, which is a further modification of Example 11, as shown in Figures 51, 52A, and 52B, the cutting surface CPF is the same as in Example 11 except that it has a helical path JX that exposes the cutting surface CPF created between adjacent square pyramidal QRPs, extending spirally along the longitudinal axis LT, rather than being an acute-angled V-shaped groove.

[0119] In the cutting process using the cutting surface CPF of the modified ultrasonic surgical instrument, the cutting surface CPF comes into contact with the bone or other tissue (not shown) to be cut. As a result, the cutting fragments (not shown) generated by the cutting process are discharged from the front and rear end faces of the cutting section CP through the gap between the helical path JX of the cutting surface CPF and the contact surface. If the twist of the helical path JX of the cutting surface CPF is large, the helical path JX becomes a gentle slope, and the cutting fragments are more easily discharged. Conversely, the smaller the twist of the helical path JX, the steeper the helical path JX becomes, and the more difficult it is for the cutting fragments to be discharged.

[0120] Thus, according to a further modification of Example 11, the spiral path JX prevents clogging of the cut and crushed pieces, and allows for easy removal of the cut pieces.

[0121] (Example 15) Furthermore, Example 15 is shown in Figures 53 and 54. Figure 53 schematically shows the configuration of the surgical ultrasonic device according to Example 15, in particular the cutting surface CPF of its cutting part, and is a partial plan view of the cutting surface CPF when viewed from above (when viewed from the radial direction around the axis of the longitudinal axis). Figure 54 is a schematic perspective view showing one hexagonal pyramidal HRP formed on the cutting surface CPF of the cutting part of the cutting tip of the surgical ultrasonic device according to Example 15.

[0122] The ultrasonic surgical instrument for surgical use in Example 15 is identical to that in Example 11, except that, as shown in Figures 53 and 54, each of the multiple blade-like projections on the cutting surface CPF of the cutting tip is a hexagonal pyramidal HRP with a triangular slope NM whose vertices are the lower ends of two gentle side edges SRDs, rather than a square pyramid, and a V-shaped cut path JY is provided on the cutting surface CPF between adjacent hexagonal pyramidal HRPs, facing the slope NM which is created to extend along the longitudinal axis LT and exposing the cutting surface CPF.

[0123] The hexagonal pyramidal HRP is first formed by creating a square pyramidal QRP with a blade-like projection, as shown in Figures 6 and 7 of Example 11, which has two gentle side edges SRD (first side edge) corresponding to its long diagonal DGL and a side edge SRD2 (second side edge) that is steeper than the side edge SRD, with the side of the steeper side edge SRD2 being thinner. Next, a V-shaped cut path JY is ground and created so as to extend in the axial direction of the longitudinal axis LT that intersects the side edges SRD on both sides of the blade-like tip KS. In other words, the hexagonal pyramidal HRP with a blade-like tip KS is created by grinding the cut path JY in the axial direction of the longitudinal axis LT from the square pyramidal QRP with a blade-like tip KS, thereby forming a triangular slope NM by removing a portion of the base of the side edges SRD on both sides of the square pyramidal QRP.

[0124] According to Example 15, the following effects (1) to (3) can be obtained. (1) Since the hexagonal pyramidal HRP equipped with a blade-shaped tip KS is equipped with a triangular slope NM that is opposed to torsional vibration (compound vibration), the tissue of the area to be treated (not shown) can be finely cut with the blade-shaped tip KS, and the tissue can be crushed by striking it with the slope NM, thereby enabling rapid tissue fragmentation. Furthermore, the triangular slope NM prevents the blade-shaped tip KS from penetrating too deeply into the tissue, allowing the surgical ultrasonic device to be operated without getting caught when pulled in the axial direction of the longitudinal axis LT (direction of the white arrow in Figure 53). (2) Comparing the cross-sectional area of ​​the face of the square pyramidal QRP shown in Figures 6 and 7 of Example 11 facing the axial direction of the longitudinal axis LT with the same cross-sectional area of ​​the hexagonal pyramidal HRP shown in Figures 53 and 54, the cross-sectional area of ​​this example is smaller by the amount of the cutting path JY (the base portion of the lateral ridge SRD). Therefore, by using a hexagonal pyramidal HRP, the resistance when pulling the cutting tip 4 (surgical ultrasonic surgical instrument) in the axial direction of the longitudinal axis LT is reduced, improving the operability of the surgical ultrasonic surgical instrument. As a result, in the cutting process using the cutting surface CPF of the surgical ultrasonic surgical instrument, the cutting surface CPF comes into contact with the tissue (not shown) such as bone to be cut, thus reducing the resistance of the cutting tip 4 catching in the axial direction of the longitudinal axis LT (direction of the white arrow in Figure 53). (3) The cutting fragments generated by contact cutting with tissue are discharged from the front and rear end faces of the cutting section CP through the gap between the cutting path JY of the cutting surface CPF and the contact surface, so the cutting path JY prevents clogging of the cutting fragments and allows for easy removal of the cut and crushed cutting fragments.

[0125] (Example 16) Furthermore, Example 16 is shown in Figures 55, 56A, and 56B. Figure 55 schematically shows the configuration of the surgical ultrasonic device according to Example 16, in particular the cutting surface CPF of the cutting part, and is a partial plan view of the cutting surface CPF when viewed from above (when viewed from the radial direction around the axis of the longitudinal axis). Figure 56A is a partial side view showing the cutting part CP of the ultrasonic device in a modified example of Example 16, which has a plurality of hexagonal pyramidal HRPs around the entire circumference of the tip of the cutting tip 4. Figure 56B is a cross-sectional view of the cutting part CP along line xx in Figure 56A.

[0126] The ultrasonic surgical instrument for surgical use in Example 16 is identical to that in Example 15, except that, as shown in Figure 55, in addition to the V-shaped cutting path JY facing the slope NM on the cutting surface CPF, a spiral path JX is provided that extends spirally along the longitudinal axis LT, exposing the cutting surface CPF created between adjacent hexagonal pyramidal HRPs.

[0127] In Example 16, the hexagonal pyramidal HRP and the cutting path JY of the cutting surface CPF of the surgical ultrasonic device are first formed by creating a quadrangular pyramidal QRP with multiple blade-like projections, each surrounded by a spiral path JX, as shown in Figures 52A and 52B of Example 15. Next, a V-shaped cutting path JY is created by grinding and forming it so as shown by the dashed line in Figure 52B, extending in the axial direction of the longitudinal axis LT that intersects the side edges SRD on both sides of the blade-like tip KS. That is, the hexagonal pyramidal HRP with a blade-like tip KS is created by grinding the cutting path JY in the axial direction of the longitudinal axis LT from the quadrangular pyramidal QRP with a blade-like tip KS, thereby forming a triangular slope NM by removing a portion of the base of the side edges SRD on both sides of the quadrangular pyramidal QRP.

[0128] According to Example 16, the following effects (1) to (3) can be obtained. (1) Since the hexagonal pyramidal HRP equipped with a blade-shaped tip KS has a triangular slope NM that is opposed to torsional vibration (compound vibration), the tissue of the area to be treated (not shown) can be finely cut by the blade-shaped tip KS, and the tissue can be crushed by striking it with the slope NM, thereby enabling rapid tissue fragmentation. (2) Comparing the cross-sectional area of ​​the surface facing the axial direction of the longitudinal axis LT of the square pyramidal QRP shown in Figure 52B, a modified example of Example 11, with the same cross-sectional area of ​​the hexagonal pyramidal HRP shown in Figure 56B, the cross-sectional area of ​​this example is smaller by the amount of the cutting path JY (the base portion of the side ridge SRD). Therefore, by using a hexagonal pyramidal HRP, the resistance when pulling the cutting tip 4 (surgical ultrasonic surgical instrument) in the axial direction of the longitudinal axis LT is reduced, and the operability of the surgical ultrasonic surgical instrument is improved. As a result, in the cutting process using the cutting surface CPF of the ultrasonic surgical instrument, the cutting surface CPF comes into contact with the bone or other tissue (not shown) to be cut, thus reducing the resistance of the cutting tip 4 from catching. (3) The cutting fragments generated by contact cutting with tissue are discharged from the front and rear end faces of the cutting section CP through the gap between the helical path JX and the cut-through path JY of the cutting surface CPF and the contact surface, so that the helical path JX and the cut-through path JY prevent clogging of the cutting fragments and allow for easy removal of the cut and crushed cutting fragments.

[0129] (Modified Example 16) The modified ultrasonic surgical instrument for surgical use shown in Figure 56A of Example 16 is identical to Example 16 except that it is provided with a cylindrical part DD, which is a base having a cylindrical surface CPFb without a hexagonal pyramidal HRP between the cutting part CP at the front end of the trunk of the cutting tip 4 and the trunk. The radius of the cylindrical surface CPFb from the longitudinal axis LT of the cylindrical part DD is approximately the same as the valley diameter of the hexagonal pyramidal HRP (radius to the cutting surface CPF). Since the diameter of the cylindrical part DD is approximately the same as the valley diameter of the hexagonal pyramidal HRP, the torsional amplitude does not decrease. That is, if the torsional angle is the same, the torsional amplitude will be the same if the distance from the longitudinal axis LT to the tip of the hexagonal pyramidal HRP (blade tip KS) is the same.

[0130] According to the modified example of Example 16, since there is no hexagonal pyramidal HRP on the surface of the cylindrical portion DD, it prevents the hexagonal pyramidal HRP from penetrating deeper into the tissue than its height, allowing the surgical ultrasonic device to be operated without snagging when pulled in the axial direction of the longitudinal axis LT (in the direction of the white arrow in Figure 56A).

[0131] For example, if a slope surface SM without a hexagonal pyramidal HRP is provided between the stem of the cutting tip 4 and the cutting portion CP, as shown by the dashed line in Figure 52A, and the cutting portion CP penetrates deeply into the tissue up to the slope surface without the hexagonal pyramidal HRP, the tissue cannot be cut by the slope surface without the hexagonal pyramidal HRP. When pulling in the axial direction of the longitudinal axis LT, the slope surface without the hexagonal pyramidal HRP may become a resistance and cause snagging. However, according to the modification in Example 16, the cylindrical portion DD allows the surgical ultrasonic device to be operated without snagging.

[0132] Furthermore, a modified example of Example 11 is shown in Figure 57. Figure 57 is a schematic partial plan view of the cutting surface of the cutting tip of the surgical ultrasonic surgical instrument, which is the modified example, when viewed from above (visually from the radial direction around the longitudinal axis).

[0133] The vibration conversion mechanism SHK generates a composite vibration in the cutting portion CP at the tip of the cutting tip 4, which is a combination of longitudinal vibration and torsional vibration. As shown in Figure 57, the cutting surface CPF vibrates in a composite manner, tracing a diagonal straight trajectory CJ (bidirectional arrow) with respect to the longitudinal axis LT. The diagonal straight trajectory CJ with respect to the longitudinal axis LT intersects the torsional direction TW at an angle φ. Therefore, it is preferable that each of the multiple hexagonal pyramidal HRPs equipped with side edges SRD on the cutting surface CPF be formed such that, when the cutting surface CPF is viewed from above, the two gentle side edges SRD (first side edge) extend along the diagonal straight trajectory CJ with respect to the longitudinal axis LT. This is because the two gentle side edges SRD and the blade-shaped tip KS of the hexagonal pyramidal HRP sharply cut the part to be treated (not shown). In other words, as shown in Figure 57, the cutting surface CPF is formed by aligning multiple hexagonal pyramidal HRPs in a way that the angle (projection angle φ) between the two side edges SRD (first side edge) of the hexagonal pyramidal HRP and the torsional direction TW is within a range (0 ≤ φ < 90 degrees) where it is smaller than 90 degrees (longitudinal axis LT). Although the cutting surface CPF of Example 16, derived from a further modification of Example 11, describes the cutting portion of a non-tubular cutting tip, Example 16, although not shown, can also be applied to the cutting portion of a tubular cutting tip, derived from a further modification of Example 11.

[0134] Any of the above embodiments, examples, and modifications can be combined and are included within the scope of the present invention.

[0135] 1. Ultrasonic surgical instrument for surgical use 3. Handle section 3DC. Supply passage 4. Cutting tip (vibration transmitter) 4SC, 6SC, 11SC. Suction passage 5. Sheath tube 6. Suction tube connecting tube 7. Electrical cord 7a, 7b. Wiring 8. Plug 9. Water inlet 10. O-ring 11. Front plate 12. Transducer 13. Backing plate LP. Fluid passage ST. Seal mechanism LT. Longitudinal axis direction TW. Torsional direction CP. Cutting section CPF. Cutting surface QRP, QRP1. Square pyramid HRP. Hexagonal pyramid NM. Slope NM SHK. Vibration conversion mechanism TT. Thin section HT. Thick section HTP. Through hole in thick section LP. Fluid passage ST. Seal mechanism FS. Front end support structure BS. Rear end support structure KS. Blade-shaped tip SRD, SRD2 Side ridge NM, Slope JX, Spiral path PP, Projection apex V1, V2, Valley bottom VV, Valley

Claims

1. The device comprises: a transducer that generates longitudinal vibrations, which are ultrasonic vibrations in the direction of the longitudinal axis; a vibration conversion mechanism connected to the transducer that converts the longitudinal vibrations into compound vibrations including a torsional vibration component in the torsional direction around the longitudinal axis; and a cutting tip that extends from the proximal end to the distal end and is connected to the vibration conversion mechanism at the proximal end and has a cutting section at the distal end for cutting the part to be treated, and transmits the compound vibrations to the cutting section, wherein the cutting section has a cutting surface that vibrates compoundly around the longitudinal axis in the radial direction around the axis, the cutting surface has a plurality of pyramids, each aligned from the distal end of the cutting tip and each having a protruding vertex, and the relationship between the amplitude d1 and the protruding vertex Ld1 of the plurality of pyramids is given by the following equation, A surgical ultrasonic device characterized by being formed such that 2 × d1 ≥ Ld1.

2. The ultrasonic surgical instrument according to claim 1, characterized in that the plurality of pyramidal pyramids include pyramidal pyramids in which at least two rows from the distal end of the cutting tip are formed to be higher than the subsequent pyramidal pyramids, and the subsequent lower pyramidal pyramids.

3. The surgical ultrasonic surgical instrument according to claim 2, characterized in that the plurality of pyramidal shapes are formed such that their height gradually decreases from the highest one at the distal end of the cutting tip toward the proximal end of the cutting tip.

4. The surgical ultrasonic surgical instrument according to claim 2, characterized in that, among the plurality of pyramidal pyramids, the pyramidal pyramid with the highest distal end of the cutting tip is formed thinly by making the side toward the proximal end of the cutting tip a concave curved surface.

5. The surgical ultrasonic surgical instrument according to claim 2, characterized in that the cutting surface is formed to complete a full rotation around the axis of the longitudinal axis.

6. The ultrasonic surgical instrument according to claim 5, characterized in that the plurality of pyramidal shapes on the cutting surface are formed to be aligned spirally around the longitudinal axis.

7. The surgical ultrasonic surgical instrument according to claim 2, characterized in that the cutting surface includes a leading pyramid lower than the lower pyramid in the first row at the very tip of the cutting tip, and a valley deeper than the valley between the lower pyramids is formed between the leading pyramid and the highest pyramid in the second row from the very tip of the cutting tip.

8. The surgical ultrasonic surgical instrument according to claim 2, characterized in that at least the tall pyramids among the plurality of pyramids are formed with an uneven tip shape having a plurality of segmented projection vertices and valleys between the segmented projection vertices, which are divided at the tip of the projection vertex.

9. The surgical ultrasonic surgical instrument according to claim 1, characterized in that the plurality of pyramidal structures are formed with an uneven tip shape having a plurality of divided protrusion vertices and valleys between the divided protrusion vertices, which are divided at the tip of the protrusion vertex.

10. The cutting portion has a cylindrical portion that is coaxial with the trunk of the cutting tip, has a diameter larger than the diameter of the trunk, and supports the cutting surface, and the cutting surface is formed on one side surface of the cylindrical portion such that, when TL1 is the distance between the furthest projection vertices of the plurality of pyramids in a direction perpendicular to the longitudinal axis, and TL2 is the diameter of the cylindrical portion, the following condition, TL1 ≥ TL2, is satisfied, as described in claim 1.

11. The ultrasonic surgical instrument for surgical use according to claim 1, characterized in that each of the plurality of pyramidal shapes has a blade-shaped tip at the apex of the projection, and has two first lateral ridges extending from the blade-shaped tip inclined in the direction of the longitudinal axis from the twist direction, and a second lateral ridge intersecting the first lateral ridge more steeply than the first lateral ridge at the blade-shaped tip.

12. The surgical ultrasonic surgical instrument according to claim 11, characterized in that the cutting portion has a cylindrical portion that is coaxial with the trunk of the cutting tip and has a diameter larger than the diameter of the trunk, and supports the cutting surface, and the cutting surface is formed on one side portion of the cylindrical portion such that it has a cylindrical surface without the pyramidal shape between the trunk of the cutting tip and the cutting surface.

13. The surgical ultrasonic surgical instrument according to any one of claims 11 to 12, wherein the cutting tip is a tubular body having a hollow portion that penetrates the cutting portion from the proximal end to the distal end, and the cutting tip has a thin-walled portion that is thinner than other portions that are arranged opposite to it in a direction intersecting the longitudinal axis so as to extend from the proximal end to the distal end along the radial direction toward the cutting surface and the longitudinal axis.

14. The surgical ultrasonic surgical instrument according to claim 13, characterized in that the cutting tip has a through-hole in the thick portion that penetrates from the hollow portion through the thick portion which is thicker than the thin portion, and penetrates to the outside of the cutting tip.

15. The surgical ultrasonic surgical instrument according to claim 14, further comprising a sheath tube that exposes the cutting portion and covers the vibration conversion mechanism and the cutting tip, defining a fluid flow path between the two, and a sealing mechanism that liquid-tightly seals the vibration conversion mechanism from the fluid flow path.

16. The ultrasonic surgical instrument for surgical use according to claim 15, characterized in that the sealing mechanism has an O-ring that seals the cutting tip at a position near the node of the torsional vibration caused by the vibration conversion mechanism.

17. An ultrasonic surgical instrument for surgical procedures, comprising: a transducer that generates longitudinal vibrations which are ultrasonic vibrations in the direction of the longitudinal axis; a vibration conversion mechanism connected to the transducer that converts the longitudinal vibrations into compound vibrations including a torsional vibration component in the torsional direction around the longitudinal axis; and a tubular cutting tip extending from the proximal end to the distal end, connected to the vibration conversion mechanism at the proximal end and having a cutting section at the distal end for cutting a target area, and transmitting the compound vibrations to the cutting section, wherein the cutting section has a cutting surface oriented radially around the axis of the longitudinal axis, and the cutting tip has a thin-walled portion that is thinner than other portions and is positioned opposite to the cutting tip in a direction intersecting the longitudinal axis so as to extend from the proximal end to the distal end along the radial direction toward the cutting surface and the longitudinal axis.

18. The surgical ultrasonic surgical instrument according to claim 17, characterized in that the cutting tip has a hollow portion that penetrates the cutting portion from the proximal end to the distal end, and the cutting tip has a through-hole in the thick portion that penetrates from the hollow portion through a thick portion which is thicker than the thin portion, to the outside of the cutting tip.

19. The surgical ultrasonic surgical instrument according to claim 18, further comprising a sheath tube that exposes the cutting portion and covers the vibration conversion mechanism and the cutting tip, defining a fluid flow path between the two, and a sealing mechanism that liquid-tightly seals the vibration conversion mechanism from the fluid flow path.

20. The ultrasonic surgical instrument for surgical use according to claim 19, characterized in that the sealing mechanism has an O-ring that seals the cutting tip at a position near the node of the torsional vibration caused by the vibration conversion mechanism.

21. The surgical ultrasonic surgical instrument according to any one of claims 17 to 20, wherein the cutting surface is arranged with a plurality of square pyramids, each having a side edge, and each of the plurality of square pyramids is configured such that, when the cutting surface is viewed from above, the diagonal extending in the torsional direction or the diagonal extending at an angle from the torsional direction to the longitudinal axis is longer than the diagonal of the two diagonals.

22. The surgical ultrasonic device according to claim 21, characterized in that two side edges corresponding to the long diagonals of each of the plurality of square pyramids extend along a diagonal straight trajectory with respect to the longitudinal axis of the compound vibration.

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