Ultrasonic treatment tool

Abstract

This ultrasonic treatment tool comprises: an ultrasonic treatment unit 12 which is provided on the tip side of a tubular member for insertion into a subject and which applies ultrasonic vibration to biological tissue; and a support member 10 which supports the ultrasonic treatment unit 12. The ultrasonic treatment unit 12 comprises: an ultrasonic transducer 13 for generating ultrasonic vibration; and an ultrasonic blade 14 which is connected to the tip-side end of the ultrasonic transducer 13 and which applies the ultrasonic vibration generated by the ultrasonic transducer 13 to biological tissue. The support member 10 supports, within the ultrasonic treatment unit 12 that is housed therein, a first node position of the vibration of the ultrasonic transducer 13 and a second node position of the vibration of the ultrasonic blade 14.

Description

Ultrasonic Treatment Device

[0001] The present invention relates to an ultrasonic treatment device.

[0002] Conventionally, ultrasonic treatment devices that apply ultrasonic vibrations to a target area of ​​biological tissue (hereinafter referred to as the treatment target) to treat the target area have been known (see, for example, Patent Document 1). The ultrasonic treatment device described in Patent Document 1 has an ultrasonic treatment unit provided at the distal end of a tubular member that is inserted into the subject. The ultrasonic treatment unit includes an ultrasonic transducer that generates ultrasonic vibrations and an ultrasonic blade that is connected to the distal end of the ultrasonic transducer and has a treatment portion that applies the ultrasonic vibrations generated by the ultrasonic transducer to the target area.

[0003] A typical ultrasonic treatment device employs an ultrasonic treatment unit in which an ultrasonic transducer is provided on the proximal end side of a tubular member, an ultrasonic blade is inserted into the tubular member, and a treatment portion protrudes to the outside from the distal end of the tubular member. That is, the ultrasonic treatment device described in Patent Document 1 employs an ultrasonic treatment unit that is smaller than the ultrasonic treatment units used in typical ultrasonic treatment devices.

[0004] US Patent Application Publication No. 2023 / 0240702

[0005] In ultrasonic treatment units used in general ultrasonic treatment instruments, a support structure is adopted in which multiple vibration node positions of the ultrasonic blade are supported by supports in order to stably support the ultrasonic blade. However, when a small ultrasonic treatment unit such as the ultrasonic treatment instrument described in Patent Document 1 is used, it is difficult to adopt the above-mentioned support structure. Therefore, there is a need for a technology that can stably support the ultrasonic blade and appropriately accommodate the miniaturization of the ultrasonic treatment unit.

[0006] The present invention has been made in view of the above, and an object of the present invention is to provide an ultrasonic treatment device that can appropriately accommodate miniaturization of an ultrasonic treatment unit.

[0007] In order to solve the above-mentioned problems and achieve the object, an ultrasonic treatment device according to the present invention comprises a tubular member to be inserted into a subject, an ultrasonic treatment unit provided at the distal end of the tubular member and treating biological tissue by applying ultrasonic vibrations to the biological tissue, and a support member supporting the ultrasonic treatment unit, wherein the ultrasonic treatment unit comprises an ultrasonic transducer that generates the ultrasonic vibrations, and an ultrasonic blade connected to the distal end of the ultrasonic transducer and having a treatment portion that applies the ultrasonic vibrations generated by the ultrasonic transducer to the biological tissue, and the support member accommodates the ultrasonic treatment unit inside with the treatment portion protruding outward, and supports a first nodal position of the vibration of the ultrasonic transducer and a second nodal position of the vibration of the ultrasonic blade when the ultrasonic transducer and the ultrasonic blade of the ultrasonic treatment unit accommodated inside vibrate at a predetermined resonant frequency, respectively.

[0008] FIG. 1 is a diagram showing an ultrasonic treatment device according to an embodiment. FIG. 2 is a diagram illustrating the configuration of an ultrasonic treatment unit. FIG. 3 is a diagram illustrating the configuration of an ultrasonic treatment unit. FIG. 4 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 5 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 6 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 7 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 8 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 9 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 10 is a diagram illustrating a structure for amplifying amplitude in an ultrasonic treatment unit. FIG. 11 is a diagram illustrating a modified example of the embodiment.

[0009] Hereinafter, a mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings. Note that the present invention is not limited to the embodiment described below. Furthermore, in the description of the drawings, the same parts are given the same reference numerals.

[0010] [Overview of Ultrasonic Treatment Instrument] FIG. 1 is a diagram illustrating an ultrasonic treatment instrument 1 according to an embodiment. Hereinafter, one side along the central axis Ax1 of the sheath 7 will be referred to as the distal end side Ar1, and the other side will be referred to as the proximal end side Ar2. The ultrasonic treatment instrument 1 applies treatment energy to a region of biological tissue to be treated (hereinafter referred to as the treatment target) to treat the treatment target. The treatment energy in this embodiment is ultrasonic energy and high-frequency energy. Treatments that can be performed by the ultrasonic treatment instrument 1 according to this embodiment include coagulation (sealing) of the treatment target, incision of the treatment target, and the like. Coagulation and incision may be performed simultaneously. The treatment energy applied to the treatment target is not limited to both ultrasonic energy and high-frequency energy, and may be ultrasonic energy alone.

[0011] As shown in FIG. 1, the ultrasonic treatment device 1 includes a holding case 2, an operating handle 3, a bending operation section 4, a switch 5, a rotating knob 6, a sheath 7, a bending section 8, and an end effector 9.

[0012] The holding case 2 supports the entire ultrasonic treatment instrument 1. The operating handle 3 is movably attached to the holding case 2 and receives opening and closing operations by an operator such as a surgeon. The bending operation unit 4 is rotatably provided in a state exposed to the outside from the side surface of the base end side Ar2 of the holding case 2 and receives bending operations by an operator such as a surgeon. The switch 5 is provided in a state exposed to the outside from the side surface of the tip end side Ar1 of the holding case 2 and receives treatment operations by an operator such as a surgeon.

[0013] The rotation knob 6 has a generally cylindrical shape coaxial with the central axis Ax1, and is provided on the distal end side Ar1 of the holding case 2. The rotation knob 6 is rotated by an operator such as a surgeon. This rotation causes the rotation knob 6 to rotate about the central axis Ax1 relative to the holding case 2. Furthermore, the rotation of the rotation knob 6 causes the sheath 7, the bending portion 8, and the end effector 9 to rotate about the central axis Ax1.

[0014] The sheath 7 is a cylindrical pipe and corresponds to a tubular member according to the present invention. The end of the proximal end Ar2 of the sheath 7 is inserted into the rotary knob 6 and fixed to the inner surface of the rotary knob 6.

[0015] The bending section 8 is provided at the end of the distal end side Ar1 of the sheath 7, and connects the end effector 9 to the sheath 7 in a bendable manner. That is, the end effector 9 is bent relative to the sheath 7 by a bending mechanism (not shown) operating in response to a bending operation of the bending operation section 4 by an operator such as a surgeon. The bending mechanism (not shown) is configured using, for example, a wire or a rod, and connects the bending operation section 4 and the end effector 9 through the inside of the holding case 2 and the inside of the sheath 7.

[0016] The end effector 9 is connected to the end of the distal end side Ar1 of the bending portion 8 and performs treatment on a treatment target. As shown in FIG. 1 , the end effector 9 includes a support member 10, a jaw 11, and an ultrasonic treatment unit 12.

[0017] The support member 10 is a member that is connected to an end of the distal end side Ar1 of the bending portion 8 and supports the jaw 11 and the ultrasonic treatment unit 12. The support member 10 is configured by a cylindrical body whose end of the proximal end side Ar2 is connected to the end of the distal end side Ar1 of the bending portion 8. The support structure of the ultrasonic treatment unit 12 in the support member 10 will be described later in "Support structure of ultrasonic treatment unit in support member."

[0018] The jaw 11 is at least partially made of a conductive material and is rotatably supported on the end of the distal end side Ar1 of the support member 10. An opening / closing mechanism (not shown) operates in response to an opening / closing operation of the operating handle 3 by an operator such as a surgeon, causing the jaw 11 to rotate with respect to the end of the distal end side Ar1 of the support member 10. This rotation causes the jaw 11 to open and close with respect to a treatment section 142 provided at the end of the distal end side Ar1 of the ultrasonic treatment unit 12. When the jaw 11 closes with respect to the treatment section 142, a treatment target is grasped between the jaw 11 and the treatment section 142.

[0019] The ultrasonic treatment unit 12 generates ultrasonic vibrations under the control of an external control device (not shown). The ultrasonic treatment unit 12 is inserted into the support member 10 and supported by the support member 10 with the treatment section 142 protruding from the distal end side Ar1 of the support member 10. The detailed configuration of the ultrasonic treatment unit 12 will be described later in "Configuration of Ultrasonic Treatment Unit."

[0020] An external control device (not shown) detects a treatment operation on the switch 5 by an operator such as a surgeon via the electric cable C. When the control device detects the treatment operation, it applies treatment energy to the treatment target grasped between the jaw 11 and the treatment portion 142 via the electric cable C.

[0021] For example, when ultrasonic energy is applied to a treatment target, an external control device (not shown) supplies driving power to a piezoelectric element unit 15 (described later) in the ultrasonic treatment unit 12 via an electric cable C. This causes the piezoelectric element unit 15 to generate longitudinal vibrations (ultrasonic vibrations) that vibrate in a direction along the central axis Ax2 (see FIGS. 2 and 3 ) of the support member 10. The treatment section 142 also vibrates at a desired amplitude due to the longitudinal vibrations. Then, ultrasonic vibrations are applied from the treatment section 142 to the treatment target held between the jaw 11 and the treatment section 142. In other words, ultrasonic energy is applied from the treatment section 142 to the treatment target.

[0022] Furthermore, for example, when applying high-frequency energy to a treatment target, an external control device (not shown) supplies high-frequency power between the jaw 11 and the ultrasonic treatment unit 12 via the electric cable C. When high-frequency power is supplied between the jaw 11 and the ultrasonic treatment unit 12, a high-frequency current is supplied to the treatment target located between the jaw 11 and the treatment section 142. In other words, high-frequency energy is applied to the treatment target.

[0023] [Configuration of Ultrasonic Treatment Unit] Next, the configuration of the ultrasonic treatment unit 12 will be described. Figures 2 and 3 are diagrams illustrating the configuration of the ultrasonic treatment unit 12. Specifically, Figure 2 is a diagram showing the inside of the support member 10, obtained by cutting the support member 10 along a plane including the central axis Ax2. Figure 3 is a diagram showing a part of the ultrasonic treatment unit 12 cut along a plane including the central axis Ax2 in Figure 2. As shown in Figures 2 and 3, the ultrasonic treatment unit 12 includes an ultrasonic transducer 13 and an ultrasonic blade 14.

[0024] The ultrasonic transducer 13 is a part that generates ultrasonic vibrations. The ultrasonic transducer 13 includes a piezoelectric element unit 15 and an element holding portion 16, as shown in FIGS.

[0025] As shown in FIG. 3, the piezoelectric element unit 15 includes first and second electrode plates 151 and 152 and a plurality of (four in this embodiment) piezoelectric elements 153 .

[0026] The first and second electrode plates 151 and 152 are parts to which driving power is supplied via an electric cable C from an external control device (not shown).

[0027] 3, the first electrode plate 151 includes a plurality of (three in this embodiment) negative electrode plates 1511, a plurality of (two in this embodiment) negative electrode wiring portions 1512, and a negative electrode terminal 1513. Note that one of the two negative electrode wiring portions 1512 is not shown in FIG. 3 because it is located in a hidden position.

[0028] The negative electrode plates 1511 are each formed of an annular plate and are arranged side by side along the central axis Ax2. The negative electrode wiring portions 1512 electrically connect the outer edges of adjacent negative electrode plates 1511 to each other. The negative electrode terminal 1513 extends from the outer edge of the negative electrode plate 1511 located furthest from the base end side Ar2 toward the base end side Ar2 among the negative electrode plates 1511. The negative electrode terminal 1513 is electrically connected to an external control device (not shown) via an electric cable C.

[0029] As shown in FIG. 3 , the second electrode plate 152 includes a plurality of (two in this embodiment) positive electrode plates 1521 , a positive electrode wiring portion 1522 (one in this embodiment), and a positive electrode terminal 1523 .

[0030] The multiple positive electrode plates 1521 are each formed of annular plates and arranged side by side along the central axis Ax2. The positive electrode plates 1521 have substantially the same shape as the negative electrode plates 1511. The negative electrode plates 1511 and the positive electrode plates 1521 are alternately arranged along the central axis Ax2, as shown in FIG. 3 . The positive electrode wiring portion 1522 electrically connects the outer edges of adjacent positive electrode plates 1521. The positive electrode terminal 1523 extends from the outer edge of the positive electrode plate 1521 located furthest from the base end side Ar2 toward the base end side Ar2. The positive electrode terminal 1523 is electrically connected to an external control device (not shown) via an electric cable C. Driving power is supplied between the negative electrode terminal 1513 and the positive electrode terminal 1523 from the external control device (not shown) via the electric cable C.

[0031] Each of the plurality of piezoelectric elements 153 is formed of an annular plate and is disposed between the negative electrode plate 1511 and the positive electrode plate 1521. That is, the plurality of piezoelectric elements 153 are stacked along the central axis Ax2. A potential difference is generated in the stacking direction along the central axis Ax2 in accordance with the driving power supplied to the first and second electrode plates 151 and 152, which causes the plurality of piezoelectric elements 153 to exhibit piezoelectric characteristics and to repeatedly and alternately displace along the stacking direction. As a result, the piezoelectric element unit 15 generates ultrasonic longitudinal vibrations whose vibration direction is the stacking direction.

[0032] The element holding portion 16 is at least partially made of a conductive material, and as shown in FIG. 3, is a member in which an element mounting portion 161 and a blade mounting portion 162 are integrally formed, and holds the piezoelectric element unit 15.

[0033] The element mounting portion 161 is a bolt that extends linearly along the central axis Ax2, and is inserted through each of the negative electrode plates 1511, the positive electrode plates 1521, and the piezoelectric elements 153. A fastening portion 17, which is a nut, is attached to the end of the base end side Ar2 of the element mounting portion 161, as shown in FIG.

[0034] 3, the blade mounting portion 162 is provided at the end of the distal end side Ar1 of the element mounting portion 161 and has a generally cylindrical shape extending linearly toward the distal end side Ar1 along the central axis Ax2. The blade mounting portion 162 has a larger diameter than the element mounting portion 161. Therefore, the negative electrode plates 1511, the positive electrode plates 1521, and the piezoelectric elements 153 are clamped between the blade mounting portion 162 and the fastening portion 17 with the element mounting portion 161 penetrating along the central axis Ax2, thereby being fastened together in a generally cylindrical shape. That is, the ultrasonic transducer 13 is configured by a bolt-clamped Langevin-type transducer.

[0035] As shown in FIG. 3, the blade mounting portion 162 has a first flange portion 1621 at the end of the base end side Ar2, the first flange portion 1621 having an outer diameter larger than that of other portions.

[0036] 3, the blade mounting portion 162 is provided with an insertion recess 1622. This insertion recess 1622 is a recess that extends linearly from the end surface of the distal end side Ar1 of the blade mounting portion 162 along the central axis Ax2 toward the proximal end side Ar2. A threaded portion 1623 that functions as a female screw according to the present invention is provided at the end of the distal end side Ar1 on the side surface of this insertion recess 1622. In the ultrasonic transducer 13, the portion where the threaded portion 1623 is provided corresponds to the connecting portion 18 according to the present invention. This connecting portion 18 includes the end surface of the distal end side Ar1 of the blade mounting portion 162.

[0037] The ultrasonic blade 14 is connected to the connecting portion 18 and applies ultrasonic vibrations generated by the ultrasonic transducer 13 to the treatment target. As shown in Figure 3, the ultrasonic blade 14 is a member in which a protruding portion 141 and a treatment portion 142 are integrally formed via an intermediate portion 143.

[0038] The intermediate portion 143 is a cylindrical member that extends linearly along the central axis Ax2. As shown in FIG. 3, the intermediate portion 143 is provided with a second flange portion 1431 that has a larger outer diameter than the other portions.

[0039] The protruding portion 141 has a smaller outer diameter than the intermediate portion 143 and is a cylindrical member that extends linearly from the end surface of the intermediate portion 143 on the base end side Ar2 toward the base end side Ar2 along the central axis Ax2. The protruding portion 141 is inserted into the insertion recess 1622. As shown in FIG. 3 , the outer peripheral surface of the protruding portion 141 has a threaded portion 1411 at the end of the distal end side Ar1, which functions as a male thread according to the present invention. The ultrasonic blade 14 is connected to the ultrasonic transducer 13 by threading the threaded portion 1411 into the threaded portion 1623. In this state, the protruding portion 141 does not contact the inner surface of the insertion recess 1622 except for the threaded portion 1411. The end surface of the distal end side Ar1 of the blade mounting portion 162 abuts against the end surface of the proximal end side Ar2 of the intermediate portion 143.

[0040] The treatment section 142 extends from the end face of the intermediate section 143 on the distal end side Ar1 toward the distal end side Ar1 along the central axis Ax2. The treatment section 142 applies ultrasonic vibrations generated by the ultrasonic transducer 13 to the treatment target.

[0041] In the ultrasonic treatment unit 12 according to this embodiment, the amplitude of the ultrasonic vibration generated by the piezoelectric element unit 15 is increased as described below.

[0042] 4 to 10 are diagrams illustrating a structure for amplifying amplitude in the ultrasonic treatment unit 12. When the piezoelectric element unit 15 generates ultrasonic vibrations, the element holding portion 16 generates ultrasonic vibrations (hereinafter referred to as first vibrations) of longitudinal vibrations with a predetermined resonance frequency f0 and a vibration direction along the central axis Ax2.

[0043] FIG. 4 is a diagram showing the change in the first vibration (v1) with respect to the change in longitudinal position (S) along the central axis Ax2 when the element holder 16 vibrates independently. Note that FIG. 4 shows the first vibration (v1) at times t=t1, t2, t3, and t4. In the first vibration at a predetermined resonance frequency f0, as shown in FIGS. 3 and 4 , the position S1, which is the end face on the distal end side Ar1 of the blade mounting portion 162 (the distal end of the element holder 16), corresponds to the first antinode position A1. In the first vibration, the position S3, which is the end face on the proximal end side Ar2 of the element mounting portion 161 (the proximal end of the element holder 16), corresponds to the first antinode position A2. Since the distal end of the element holder 16 corresponds to the first antinode position A1 and the proximal end corresponds to the first antinode position A2, the element holder 16 can vibrate at the predetermined resonance frequency f0. Position S2, which is located midway between positions S1 and S3, is the first node position N1 of the first vibration. That is, the ultrasonic transducer 13 has only one vibration node position when vibrating at a predetermined resonant frequency f0.

[0044] Here, the amplitude of the first vibration at each position (S) of the element holding unit 16 along the central axis Ax2 is defined as the first amplitude. In the first vibration of the element holding unit 16 alone, as shown in FIG. 4 , the first amplitude at the first antinode positions A1 and A2 has a magnitude V1.

[0045] In addition, when the first vibration is transmitted from the element holding portion 16, the ultrasonic blade 14 generates a longitudinal ultrasonic vibration (hereinafter referred to as the second vibration) with the vibration direction along the central axis Ax2 at the same predetermined resonant frequency f0 as the first vibration.

[0046] FIG. 5 is a diagram showing the change in the second vibration with respect to the change in longitudinal position (S') along the central axis Ax2 when the ultrasonic blade 14 vibrates alone. FIG. 5 shows the second vibration (v2) at times t=t1, t2, t3, and t4. In the second vibration with a predetermined resonant frequency f0, as shown in FIGS. 3 and 5, the position S'1, which is the end face on the distal side Ar1 of the treatment section 142 (the distal end of the ultrasonic blade 14), becomes the second antinode position A'1. In the second vibration, the position S'3, which is the end face on the proximal side Ar2 of the protruding portion 141 (the proximal end of the ultrasonic blade 14), becomes the second antinode position A'2. Since the distal end of the ultrasonic blade 14 is at the second antinode position A'1 and the proximal end is at the second antinode position A'2, the ultrasonic blade 14 can vibrate at the predetermined resonant frequency f0. Position S'2, which is located midway between positions S'1 and S'3, is the second node position N'1 of the second vibration. In other words, the ultrasonic blade 14 has only one vibration node position when vibrating at the predetermined resonant frequency f0.

[0047] Here, the amplitude of the second vibration at each position (S') of the ultrasonic blade 14 along the central axis Ax2 is defined as the second amplitude. In the second vibration of the ultrasonic blade 14 alone, as shown in Fig. 5, the second amplitude at the second antinode positions A'1 and A'2 is a magnitude V2a. The magnitude V2a of the second amplitude is the same as the magnitude V1 of the first amplitude described above.

[0048] Furthermore, in the ultrasonic blade 14, the end face on the base end side Ar2 of the intermediate portion 143 that abuts against the end face on the tip side Ar1 of the blade mounting portion 162 is located at a midpoint M that is different from the second antinode positions A'1, A'2 and the second node position N'1 of the second vibration. In this embodiment, the midpoint M is located between the second node position N'1 and the second antinode position A'2 of the second vibration, and is also located at the first antinode position A1 of the first vibration (the position of the end face on the tip side Ar1 of the blade mounting portion 162). That is, in a state where the connecting portion 18 vibrates at a predetermined resonant frequency f0, the connecting portion 18 is provided at a position that includes the antinode position (first antinode position A1) of the vibration of the ultrasonic transducer 13, and is provided at a position that is separated from the antinode position (second antinode position A'2) of the vibration of the ultrasonic blade 14.

[0049] FIG. 6 shows changes in the first and second vibrations with respect to changes in longitudinal position (S, S') along the central axis Ax2 when the ultrasonic treatment unit 12 vibrates. Note that FIG. 6 illustrates the first vibration (v1) and the second vibration (v2) at times t = t1, t2, t3, and t4. Also, in FIG. 6, the first vibration of the element holding unit 16 is indicated by a dashed line, and the second vibration of the ultrasonic blade 14 is indicated by a solid line. As shown in FIGS. 3 and 6, when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0, the element holding unit 16 performs the first vibration at the predetermined resonant frequency f0, similar to when the element holding unit 16 performs the first vibration alone. Therefore, in the direction parallel to the central axis Ax2, the first antinode positions A1, A2, and the first node position N1 are the same as the first antinode positions A1, A2, and the first node position N1 when the element holding unit 16 performs the first vibration alone. Also, when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0, the first amplitude at the first antinode positions A1 and A2 has a magnitude V1, just as when the element holding portion 16 performs the first vibration alone.

[0050] 3 and 6, when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0, the ultrasonic blade 14 also performs the second vibration at the predetermined resonant frequency f0, similar to when the ultrasonic blade 14 performs the second vibration by itself. Therefore, in the direction parallel to the central axis Ax2, the second antinode positions A'1, A'2 and the second node position N'1 are the same positions as the second antinode positions A'1, A'2 and the second node position N'1 when the ultrasonic blade 14 performs the second vibration by itself.

[0051] In the ultrasonic treatment unit 12, ultrasonic vibrations are transmitted from the element holding portion 16 to the ultrasonic blade 14 via the abutting end face of the distal side Ar1 of the blade mounting portion 162 and the abutting end face of the proximal side Ar2 of the intermediate portion 143. The abutting end face of the distal side Ar1 of the blade mounting portion 162 is located at a first antinode position A1 of the first vibration. The abutting end face of the proximal side Ar2 of the intermediate portion 143 is located at a midpoint M of the second vibration. The first antinode position A1 and the midpoint position M are located at the same position.

[0052] Fig. 7 is a diagram showing changes over time in the first vibration at the first antinode position A1 when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0. Fig. 8 is a diagram showing changes over time in the second vibration at the midpoint M when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0. As shown in Figs. 6 to 8, when the ultrasonic treatment unit 12 vibrates, the first amplitude of the first vibration at the first antinode position A1 is magnitude V1. Furthermore, the second amplitude of the second vibration at the midpoint M is magnitude V2b.

[0053] Here, the first antinode position A1 and the midpoint position M are the same position. Therefore, the magnitude V2b of the second amplitude at the midpoint position M is the same as the magnitude V1 of the first amplitude at the first antinode position A1. Furthermore, the first vibration at the first antinode position A1 and the second vibration at the midpoint position M are in phase with each other.

[0054] When the ultrasonic treatment unit 12 vibrates, the magnitude V2b of the second amplitude at a midpoint M different from the second antinode positions A'1 and A'2 is the same as the magnitude V1 of the first amplitude at the first antinode positions A1 and A2 of the first vibration. In the second vibration, the second amplitude at the second antinode positions A'1 and A'2 is larger than the second amplitude at the midpoint M. Therefore, when the ultrasonic treatment unit 12 vibrates at a predetermined resonant frequency f0, the magnitude V2c of the second amplitude at the second antinode positions A'1 and A'2 is larger than the magnitude V1 of the first amplitude at the first antinode positions A1 and A2 of the first vibration.

[0055] As described above, in this embodiment, it is possible to increase the second amplitude of the ultrasonic vibration at the second antinode position A'1 located at the tip of the ultrasonic blade 14 without providing a cross-sectional area changing section (horn) whose cross-sectional area perpendicular to the central axis Ax2 changes.

[0056] 9 is a diagram showing the change over time of the second vibration at the second antinode position A'1 of the ultrasonic blade 14 when the ultrasonic treatment unit 12 vibrates. As described above, the second antinode position A'1 is located at the tip of the ultrasonic blade 14. As shown in FIG. 9, the magnitude V2c of the second amplitude at the second antinode position A'1 is greater than the magnitude V1 of the first amplitude at the first antinode position A1. Furthermore, in the second vibration, the midpoint M is located between the second node position N'1 and the second antinode position A'2. In this case, the second vibration at the second antinode position A'1 is in opposite phase to the first vibration at the first antinode position A1.

[0057] 10 shows the magnification ratio (E) of the second amplitude at the second antinode positions A'1 and A'2 of the second vibration to the first amplitude at the first antinode positions A1 and A2 of the first vibration when the midpoint M of the ultrasonic blade 14 is changed along the central axis Ax2 between the second node position N'1 and the second antinode position A'2. As described above, the magnitude V2b of the second amplitude at the midpoint M is the same as the magnitude V1 of the first amplitude at the first antinode positions A1 and A2. Therefore, regardless of the change in the position of the midpoint M along the central axis Ax2, the magnitude V2b of the second amplitude at the midpoint M is the same as the magnitude V1 of the first amplitude at the first antinode positions A1 and A2. In other words, the magnitude V2b of the second amplitude at the midpoint M does not change due to the change in the position of the midpoint M along the central axis Ax2.

[0058] On the other hand, as the midpoint M approaches the second node position N'1, the ratio E of the second amplitude magnitude V2c at the second antinode positions A'1 and A'2 to the second amplitude magnitude V2b at the midpoint M increases. Since the first amplitude magnitude V1 at the first antinode position A1 is the same as the second amplitude magnitude V2b at the midpoint M, as shown in Fig. 10, as the midpoint M approaches the second node position N'1, the enlargement ratio E of the second amplitude magnitude V2c at the second antinode positions A'1 and A'2 to the first amplitude magnitude V1 at the first antinode positions A1 and A2 increases.

[0059] [Regarding the Connection Strength Between the Ultrasonic Transducer and the Ultrasonic Blade] Next, the connection strength between the ultrasonic transducer 13 and the ultrasonic blade 14 will be described with reference to Fig. 3. In this embodiment, as described above, the ultrasonic treatment unit 12 is provided on the distal end side Ar1 of the sheath 7. That is, the ultrasonic treatment unit 12 is smaller than ultrasonic treatment units used in general ultrasonic treatment instruments. When such a small ultrasonic treatment unit 12 is used, the connection strength between the ultrasonic transducer 13 and the ultrasonic blade 14 may be weakened.

[0060] Therefore, in this embodiment, as shown in FIG. 3, the thickness T1 of the connecting portion 18 is set to be larger than the thickness T2 of the portion 19 of the blade mounting portion 162 adjacent to the connecting portion 18.

[0061] [Support Structure of the Ultrasonic Treatment Unit in the Support Member] Next, the support structure of the ultrasonic treatment unit 12 in the support member 10 will be described with reference to Fig. 3. As shown in Fig. 3, the first flange portion 1621 is provided at a first node position N1 of the first vibration. Furthermore, the second flange portion 1431 is provided at a second node position N'1 of the second vibration.

[0062] The support member 10 supports the ultrasonic treatment unit 12 on its inner surface by the first and second flange portions 1621, 1431. This prevents the ultrasonic treatment unit 12 from bending in response to a force applied during treatment of the treatment target, and also prevents movement along the central axis Ax2 and rotation about the central axis Ax2. The support member 10 may be configured to directly support the first and second flange portions 1621, 1431, or may have another member such as rubber interposed between the support member 10 and the first and second flange portions 1621, 1431.

[0063] Here, the support at the first node position N1 by the support member 10 is fixed at least in a direction perpendicular to the longitudinal axis (central axis Ax2) of the ultrasonic treatment instrument 1. Moreover, the support is not fixed in the rotational direction of the longitudinal axis. Furthermore, the support is not fixed in the longitudinal axis direction.

[0064] The support at the second nodal position N'1 by the support member 10 is fixed at least in a direction perpendicular to the longitudinal axis (central axis Ax2) of the ultrasonic treatment instrument 1. The support is also fixed in the rotational direction of the longitudinal axis. Furthermore, the support is also fixed in the longitudinal axis direction.

[0065] The above-described embodiment of the present invention provides the following advantages. In the ultrasonic treatment device 1 according to the present embodiment, the support member 10 supports the first node position N1 and the second node position N'1 of the ultrasonic treatment unit 12 housed therein. That is, the support member 10 can support the ultrasonic treatment unit 12 at two positions (the first and second positions N1 and N'1) that are less than one wavelength of vibration, and can stably receive the force in the bending direction of the ultrasonic blade 14. Therefore, the ultrasonic treatment device 1 according to the present embodiment can stably support the ultrasonic blade 14 and appropriately accommodate miniaturization of the ultrasonic treatment unit 12.

[0066] In the ultrasonic treatment device 1 according to the present embodiment, the ultrasonic transducer 13 has only one vibration node when vibrating at a predetermined resonant frequency f0. The distal end and proximal end of the ultrasonic transducer 13 are vibration antinodes, respectively. This allows the ultrasonic treatment unit 12 to be miniaturized.

[0067] In the ultrasonic treatment device 1 according to the present embodiment, the ultrasonic blade 14 has only one vibration node when vibrating at a predetermined resonant frequency f0. The distal end and proximal end of the ultrasonic blade 14 are vibration antinodes, respectively. This allows the ultrasonic treatment unit 12 to be miniaturized.

[0068] Furthermore, in the ultrasonic treatment device 1 according to this embodiment, when the ultrasonic transducer 13 and the ultrasonic blade 14 are vibrating at predetermined resonant frequencies, the connection portion 18 is provided at a position including the antinode position of the vibration of the ultrasonic transducer 13 and at a position spaced apart from the antinode position of the vibration of the ultrasonic blade 14. This makes it possible to increase the second amplitude of the ultrasonic vibration at the second antinode position A'1 located at the tip of the ultrasonic blade 14 without providing a cross-sectional area changing portion (horn) whose cross-sectional area perpendicular to the central axis Ax2 changes. In other words, since there is no need to provide the horn, the ultrasonic treatment unit 12 can be made smaller.

[0069] While the embodiments for carrying out the present invention have been described above, the present invention should not be limited to the above-described embodiments. In the above-described embodiments, the end effector 9 is bendably connected to the sheath 7 by the bending portion 8. However, the present invention is not limited to this. The end effector 9 may be directly fixed to the sheath 7, i.e., may not be bendable relative to the sheath 7.

[0070] In the above-described embodiment, the ultrasonic transducer 13 and the ultrasonic blade 14 each have only one vibration node position when vibrating at a predetermined resonant frequency f0, but this is not limited to this and each may have two or more such node positions.

[0071] In the above-described embodiment, the jaw 11 may be omitted.

[0072] In the above-described embodiment, the ultrasonic blade 14 is provided with the protrusion 141, and the ultrasonic transducer 13 is provided with the insertion recess 1622, but this is not limiting. Conversely, a configuration in which the ultrasonic transducer 13 is provided with the protrusion 141, and the ultrasonic blade 14 is provided with the insertion recess 1622 may also be employed.

[0073] Fig. 11 is a diagram showing a modified example of the embodiment. In the above-described embodiment, the ultrasonic treatment device according to the present invention is configured as a handheld ultrasonic treatment device 1, but this is not limited to this. For example, as in this modified example shown in Fig. 11, the ultrasonic treatment device according to the present invention may be employed in a medical device 40 having a robot arm 41. Hereinafter, for convenience of explanation, the ultrasonic treatment device according to this modified example will be referred to as an ultrasonic treatment device 1A.

[0074] 11 , the robot arm 41 includes a base 410, first to fifth arm sections 411 to 415, and first to fourth joint sections 416 to 419. The base 410 is placed on a floor or the like and supports the entire medical device 40. The first to fifth arm sections 411 to 415 are connected in series by the first to fourth joint sections 416 to 419. Of the first to fifth arm sections 411 to 415, the fifth arm section 415 located at the base end is fixed on the base 410. Of the first to fifth arm sections 411 to 415, the first arm section 411 located at the tip end is detachably connected to the ultrasonic treatment instrument 1A.

[0075] The first to fourth joints 416 to 419 rotate the connected pairs of arms of the first to fifth arm units 411 to 415 relative to each other around different axes. That is, in this modification, the ultrasonic treatment instrument 1A is movable with four degrees of freedom. Note that the robot arm 41 is not limited to four degrees of freedom and may have other numbers of degrees of freedom. That is, the number of the first to fifth arm units 411 to 415 and the number of the first to fourth joint units 416 to 419 are not limited to the above numbers and may be other numbers.

[0076] Although not specifically shown, actuators are provided inside each of the first to fourth joints 416 to 419 for relatively rotating pairs of connected arms in the first to fifth arm units 411 to 415. Each actuator is driven under the control of an external control device (not shown).

[0077] As shown in FIG. 11, the ultrasonic treatment device 1A includes a detachable portion 42 in addition to the sheath 7, bending portion 8, and end effector 9 described in the above embodiment.

[0078] The detachable unit 42 is provided at the base end of the sheath 7 and serves to attach and detach the ultrasonic treatment instrument 1A to and from the robot arm 41 (first arm 411). Although not specifically shown, an actuator is provided inside the detachable unit 42 to open and close the jaw 11 relative to the treatment unit 142 and to bend the end effector 9 relative to the sheath 7 under the control of an external control device (not shown).

[0079] Even when the ultrasonic treatment device according to the present invention is employed in the medical device 40 having the robot arm 41 as in this modified example described above, the same effects as those of the above-described embodiment can be achieved.

[0080] DESCRIPTION OF SYMBOLS 1, 1A Ultrasonic treatment tool 2 Holding case 3 Operation handle 4 Bending operation section 5 Switch 6 Rotation knob 7 Sheath 8 Bending section 9 End effector 10 Support member 11 Jaw 12 Ultrasonic treatment unit 13 Ultrasonic transducer 14 Ultrasonic blade 15 Piezoelectric element unit 16 Element holding section 17 Fastening section 18 Connection section 19 Adjacent section 40 Medical device 41 Robot arm 42 Detachable section 141 Protruding section 142 Treatment section 143 Intermediate section 151 First electrode plate 152 Second electrode plate 153 Piezoelectric element 161 Element mounting section 162 Blade mounting section 410 Base section 411 First arm section 412 Second arm section 413 Third arm section 414 Fourth arm section 415 Fifth arm portion 416 First joint portion 417 Second joint portion 418 Third joint portion 419 Fourth joint portion 1411 Screw portion 1431 Second flange portion 1511 Negative electrode plate 1512 Negative electrode wiring portion 1513 Negative electrode terminal 1521 Positive electrode plate 1522 Positive electrode wiring portion 1523 Positive electrode terminal 1621 First flange portion 1622 Insertion recess 1623 Screw portion A1, A2 First antinode position A'1, A'2 Second antinode position Ar1 Tip side Ar2 Base side Ax1, Ax2 Central axis C Electrical cable N1 First node position N'1 Second node position S1 to S3, S'1 to S'3 Position T1, T2 Wall thickness

Claims

1. An ultrasonic treatment device comprising: a tubular member to be inserted into a subject; an ultrasonic treatment unit provided at the distal end of the tubular member for treating biological tissue by applying ultrasonic vibrations to the biological tissue; and a support member for supporting the ultrasonic treatment unit, wherein the ultrasonic treatment unit comprises: an ultrasonic transducer for generating the ultrasonic vibrations; and an ultrasonic blade connected to the distal end of the ultrasonic transducer and having a treatment portion for applying the ultrasonic vibrations generated by the ultrasonic transducer to the biological tissue, wherein the support member houses the ultrasonic treatment unit with the treatment portion protruding outward, and supports a first nodal position of vibration of the ultrasonic transducer and a second nodal position of vibration of the ultrasonic blade when the ultrasonic transducer and the ultrasonic blade of the ultrasonic treatment unit housed therein vibrate at predetermined resonant frequencies, respectively.

2. An ultrasonic treatment device according to claim 1, wherein the support member supports the first nodal position of the vibration of the ultrasonic transducer, and is fixed at least in a direction perpendicular to the longitudinal axis of the ultrasonic treatment device.

3. An ultrasonic treatment device according to claim 2, wherein the support member supports the first nodal position of the vibration of the ultrasonic transducer in a manner that is not fixed relative to the rotational direction of the longitudinal axis of the ultrasonic treatment device.

4. An ultrasonic treatment device according to claim 3, wherein the support member supports the first nodal position of the vibration of the ultrasonic transducer without being fixed in the longitudinal direction of the ultrasonic treatment device.

5. An ultrasonic treatment device according to claim 2, wherein the support member supports the ultrasonic blade at the second nodal position of vibration, and is fixed at least in a direction perpendicular to the longitudinal axis of the ultrasonic treatment device.

6. An ultrasonic treatment device according to claim 5, wherein the support member supports the ultrasonic blade at the second nodal position of vibration, and the support member is fixed relative to the rotational direction of the longitudinal axis of the ultrasonic treatment device.

7. An ultrasonic treatment device according to claim 6, wherein the support member supports the ultrasonic blade at the second nodal position of vibration, and the support member is fixed in the longitudinal direction of the ultrasonic treatment device.

8. An ultrasonic treatment device as described in claim 1, wherein the ultrasonic blade comprises the treatment portion and a protrusion that protrudes toward the ultrasonic transducer, and the ultrasonic transducer is provided with an insertion recess into which the protrusion is inserted.

9. The ultrasonic treatment device according to claim 1, wherein the ultrasonic transducer has only one first node position.

10. The ultrasonic treatment device according to claim 1, wherein the ultrasonic blade has only one second node position.

11. An ultrasonic treatment device as described in claim 1, wherein the connection portion of the ultrasonic transducer to the ultrasonic blade is provided at a position that includes the antinode position of the vibration of the ultrasonic transducer when the ultrasonic transducer and the ultrasonic blade are each vibrating at the resonant frequency, and is provided at a position that is spaced apart from the antinode position of the vibration of the ultrasonic blade.

12. An ultrasonic treatment device according to claim 1, wherein the distal end and proximal end of the ultrasonic transducer are positioned at antinodes of vibration when vibrating at the resonant frequency.

13. An ultrasonic treatment device according to claim 1, wherein the tip and base ends of the ultrasonic blade are positioned at antinodes of vibration when vibrating at the resonant frequency.

14. An ultrasonic treatment device as described in claim 1, wherein a first flange portion supported by the support member is provided at the first node position of the ultrasonic transducer, and a second flange portion supported by the support member is provided at the second node position of the ultrasonic blade.

15. The ultrasonic treatment device according to claim 1, further comprising a bending portion provided at the tip of the tubular member, which connects the ultrasonic treatment unit to the tubular member in a bendable manner.

16. The ultrasonic treatment device according to claim 1, further comprising a jaw that can be opened and closed relative to the treatment section and that grasps the living tissue between the treatment section and the jaw.

17. The ultrasonic treatment device according to claim 1, further comprising a handle provided on the proximal end side of the tubular member and operated by an operator.

18. The ultrasonic treatment device according to claim 1, wherein the ultrasonic treatment device is connected to the tip of a robot arm.

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