JP7316924B2 - Ultrasonic emitting instruments and ultrasonic devices - Google Patents

Description

The present disclosure relates to an ultrasonic wave emitting device that emits ultrasonic waves toward an object such as a human body, and an ultrasonic device having the ultrasonic wave emitting device.

2. Description of the Related Art An ultrasonic device that emits ultrasonic waves toward an object such as a human body is known (for example, Patent Document 1). Such an ultrasonic apparatus is used, for example, as an ultrasonic therapeutic apparatus for treating an affected area by irradiating ultrasonic waves, or an ultrasonic diagnostic apparatus for obtaining a cross-sectional secondary image of an affected area. there is As an ultrasonic therapy device, for example, a device used for HIFU (High Intensity Focused Ultrasound) therapy is known. Patent Document 1 discloses a configuration in which a substrate having a plurality of spaces (cavities), a vibration layer, and a piezoelectric element are stacked in this order as a configuration for generating vibrations that generate ultrasonic waves.

JP 2016-184821 A

An ultrasonic emission instrument according to an aspect of the present disclosure has a first surface facing one side in the thickness direction and a second surface facing the other side in the thickness direction, and along the first surface It has a plurality of vibrating elements that generate vibrations that generate ultrasonic waves at a plurality of positions in the direction, and the plurality of vibrating elements are not located on the entire surface of the first surface in planar perspective. It has an element substrate located in a region on the central side of the first surface , and a plurality of cavities individually overlapping with the plurality of vibration elements , and the edge of each cavity makes each vibration element flat. and a cavity member enclosing in perspective and defining a fixed end of each vibrating element, each of the plurality of vibrating elements having a piezoelectric layer and a first surface side with respect to the piezoelectric layer. a first electrode overlapping the piezoelectric layer, a second electrode overlapping the piezoelectric layer on the second surface side, a vibration layer overlapping the first electrode on the first surface side; wherein the vibration layer has a strength for restricting the extension of the piezoelectric layer along the first surface to bend the vibration element toward the second surface, and the first It has at least one of the strength to restrict contraction along the surface and bend the vibration element toward the first surface, and the cavity member overlaps the element substrate on the second surface side. .

An ultrasonic device according to an aspect of the present disclosure includes the ultrasonic wave emitting device described above and a drive control section that supplies AC power having a frequency within an ultrasonic frequency band to the plate-like element.

1 is a schematic diagram showing a schematic configuration of an ultrasonic device according to a first embodiment; FIG. 2 is a perspective view showing a schematic configuration of an ultrasonic wave generator of the ultrasonic device of FIG. 1; FIG. FIG. 3 is a plan view of a plate-like element of the ultrasonic generator of FIG. 2; 4 is a cross-sectional view taken along line IV-IV of FIG. 3; FIG. FIG. 3 is a perspective view showing part of the outer surface of the support of the ultrasonic generator of FIG. 2; FIG. 4 is a cross-sectional view showing a fixing structure of the plate-shaped element of FIG. 3; FIG. 7 is an enlarged view of area VII of FIG. 6; FIGS. 8(a) and 8(b) are schematic diagrams showing one example and another example of a focusing mode of ultrasonic waves. FIG. 9(a) is a schematic plan view showing a modification of connection of individual electrodes, and FIG. 9(b) is a cross-sectional view taken along line IXb-IXb of FIG. 9(a).

Hereinafter, embodiments according to the present disclosure will be described with reference to the drawings. The following drawings are schematic. Therefore, details may be omitted. Also, the dimensional ratio does not necessarily match the actual one. The dimensional ratios of the drawings do not necessarily match. Certain dimensions may be shown larger than they actually are, and certain shapes may be exaggerated.

FIG. 1 is a schematic diagram showing a schematic configuration of an ultrasonic device 1 according to an embodiment.

The ultrasonic device 1 is used for HIFU treatment, for example. For example, the ultrasonic device 1 focuses ultrasonic waves on the affected area 103 of the patient 101 (or on a foreign object such as a calculus; the same shall apply hereinafter). The affected part 103 is denatured by heat or the like generated thereby. The ultrasound apparatus 1 may be configured to treat any part of the human body, or any disease. In other words, the frequency and intensity of the ultrasonic waves emitted by the ultrasonic device 1, the dimensions of each part of the ultrasonic device 1, and the like may be appropriately set. Ultrasonic waves are generally considered to be sound waves of 20 kHz or higher. There is no general upper limit for the frequency of ultrasonic waves, but it may be 5 GHz, for example.

The ultrasonic device 1 is arranged adjacent to a patient 101, and includes an ultrasonic wave emitting device 3 (hereinafter sometimes simply referred to as “radiating device 3”) that directly radiates ultrasonic waves. and an apparatus main body 5 for supplying electric power to and the like.

(ultrasonic emitting instrument)
The radiation instrument 3 has a generator 7 for generating ultrasonic waves and a bag 9 interposed between the generator 7 and the patient 101 . The generator 7 radiates ultrasonic waves from, for example, a concave surface 7a facing the patient 101 side. The shape of the concave surface 7a is, for example, roughly a shape obtained by cutting a part of a spherical surface (the inner surface thereof). Therefore, the ultrasonic waves radiated from the concave surface 7a are focused near the center of the sphere (from another point of view, the affected area 103). The bag 9 contains the liquid LQ at least when the ultrasonic device 1 is used. The liquid LQ contributes, for example, to mitigating abrupt changes in acoustic impedance between the concave surface 7a and the patient's 101 body surface.

Liquid LQ is, for example, water. Also, for example, the liquid LQ may contain water and appropriate additives. The additive may be, for example, for adjusting acoustic impedance. The acoustic impedance of the liquid LQ is, for example, 1×10 ⁶ kg/(m ² s) or more and 2×10 ⁶ kg/(m ² s) or less, or 1.3×10 ⁶ kg/(m ² s). ) or more and 1.7×10 ⁶ kg/(m ² ·s) or less. For reference, the acoustic impedances of various substances are exemplified: water: about 1.5×10 ⁶ kg/(m ² s), air: about 0, fat: about 1.4×10 ⁶ kg/(m ^{2 )} • s), muscle: about 1.7 x ¹⁰⁶ kg/( ^m2 • s).

(generator)
FIG. 2 is a schematic diagram for explaining the main configuration of the generator 7. As shown in FIG. In FIG. 2, the upper side of the paper is the patient 101 side. That is, FIG. 2 is a perspective view of the generating portion 7 viewed from the side of the concave surface 7a.

The generator 7 has, for example, a plurality of plate-shaped elements 11 that each emit ultrasonic waves, and a support 13 that holds the plurality of plate-shaped elements 11 . The support 13 has, for example, a frame shape (frame shape, frame structure shape), and holds the outer edges of the plurality of plate-shaped elements 11 so as to expose the plurality of plate-shaped elements 11 to the patient 101 side. In addition to this, the generator 7 may have, for example, a housing or the like having an appropriate shape that covers the illustrated configuration from the side opposite to the patient 101 .

(Arrangement of plate-like elements)
The plate-like element 11 is, for example, generally configured in a flat plate shape. One of the front and back surfaces (the widest pair of surfaces) of the plate shape is a radiation surface 11 a that radiates ultrasonic waves toward the patient 101 . A plurality of plate-shaped elements 11 are arranged in parallel with each other and inclined (in different directions) so that the radiation surfaces 11a face a common focusing area (affected area 103), forming the aforementioned concave surface 7a. are doing. Accordingly, the concave surface 7a is not composed of curved surfaces, but is composed of a combination of a plurality of flat surfaces (radiating surfaces 11a).

The arrangement pattern of the plurality of plate-shaped elements 11 may be set appropriately. In the illustrated example, a plurality of plate-like elements 11 are arranged in the circumferential direction of the concave surface 7a (the direction along the outer periphery of the concave surface 7a) to form an annular element row 8 (indicated by arrows). The element rows 8 may be provided in a plurality of rows (for example, concentrically) in a multiple (double or more) ring shape in plan view of the concave surface 7a (example shown), or may be provided in only one row. . The pitch of the plate-like elements 11 in each element row 8 may be constant (the example shown in the drawing) or may not be constant. The number of plate-like elements 11 included in each element row 8 may be set appropriately. Also, this number may be the same or different between the plurality of element rows 8 .

In the illustrated example, the innermost region (central portion 65, which will be described later) of the concave surface 7a is a non-placement region of the plate-shaped element 11. As shown in FIG. Appropriate electronic components and the like may be arranged in such regions. For example, an ultrasonic sensor for detecting the position of the affected part 103, a visual sensor for detecting the position of a marker attached to the body surface of the patient 101 to indicate the position of the affected part 103, and/or a plurality of plate-shaped elements 11 A receiving unit may be provided for receiving a reflected wave of the ultrasonic wave emitted from. Further, the innermost region of the concave surface 7a may have an opening. The opening may be for example to pass visible light detected by the visual sensor and/or ultrasonic waves detected by the ultrasonic sensor. Further, the innermost region of the concave surface 7a may be used as the arrangement region of the plate-like element 11 .

(Planar shape of plate-shaped element)
FIG. 3 is a plan view of the plate-like element 11. FIG.

The planar shape of the plate-shaped element 11 and the dimensions of the planar shape may be appropriately set. For example, the plurality of plate-like elements 11 may have the same shape and size, or may include two or more types of plate-like elements 11 having different shapes and/or sizes. Further, the planar shape of the plate-like elements 11 may be a shape in which the gap between the adjacent plate-like elements 11 is relatively small (a shape in which a spherical surface is divided) (see FIGS. 2 and 3). Example), it does not have to be such a shape. The latter may, for example, be circular.

In the examples of FIGS. 2 and 3, the planar shape of the plate-like elements 11 is trapezoidal, which is an example of a shape in which the gaps between the plate-like elements 11 are relatively small. It should be noted that the fact that the concave surface 7a can be formed by polygons other than trapezoids so as to reduce the gaps between the plate-like elements 11 is, for example, a regular polyhedron (Platonic solid), a semi-regular polyhedron (Archimedean solid), and a Platonic polyhedron. It is evident from the solid, as well as from the dome shape realized in various technical fields.

More specifically, the trapezoidal shape of the plate-like element 11 has, for example, an upper base 11d inside the concave surface 7a and a lower base 11e outside the concave surface 7a, as labeled in FIG. It is an isosceles trapezoid having a pair of legs 11f of length. The length of the upper base 11d, the length of the lower base 11e, and the height of the trapezoid (the distance between the upper base 11d and the lower base 11e) may be set appropriately, and any length is can be longer.

As described above, the plurality of plate-like elements 11 are arranged in the circumferential direction of the concave surface 7a to form the annular element row 8. As shown in FIG. In each element row 8, the trapezoidal legs 11f of adjacent plate-shaped elements 11 are adjacent to each other. Adjacent legs 11f may or may not be parallel to each other. In the latter case, the interval between the legs 11f may be relatively wide either inside or outside the concave surface 7a. Further, in adjacent element rows 8, the trapezoidal upper base 11d of the plate-shaped element 11 of one element row 8 and the trapezoidal lower base 11e of the plate-shaped element 11 of the other element row 8 are adjacent to each other. .

(Structure of plate-shaped element)
As shown in FIG. 3, one plate-shaped element 11 has a plurality of vibration elements 15 (specifically, piezoelectric elements). The vibrating element 15 is a part that produces vibrations that generate ultrasonic waves. The number, position, planar shape, size, etc. of the vibration elements 15 may be appropriately set.

In the illustrated example, the plurality of vibrating elements 15 are arranged with a substantially uniform density along the planar direction of the plate-like element 11 (the direction along the plane; hereinafter the same). More specifically, the plurality of vibrating elements 15 are arranged vertically and horizontally at a constant pitch. However, the plurality of vibrating elements 15 may be shifted by a half pitch between adjacent rows, may be arranged along a plurality of concentric circles, may be arranged radially, or may be arranged uniformly. It may be arranged at a density other than The relative relationship between the arrangement direction of the plurality of vibration elements 15 and the direction in which each part of the outer edge of the plate-like element 11 extends may also be set appropriately.

The area of the arrangement region of the plurality of transducers 15 (for example, the smallest convex polygon that accommodates the plurality of transducers 15) is, for example, the area of the plate-like element 11 (or the area exposed from the support 13 when viewed from the patient 101 side). 1/5 or more, 1/2 or more, 2/3 or more, or 4/5 or more of the total area. 4/5 or more may be regarded as a state in which a plurality of vibrating elements 15 are arranged over the entire surface of the plate-like element 11 . When the plurality of vibration elements 15 are not arranged over the entire surface of the plate-shaped element 11, the arrangement region of the plurality of vibration elements 15 is located in an appropriate range such as the central side or the outer edge side of the plate-shaped element 11. You can The shape of the arrangement area is also arbitrary.

In the illustrated example, the plane shape of the vibrating element 15 is circular. From another point of view, the planar shape is a linearly symmetrical or rotationally symmetrical shape. However, the planar shape may be other shapes such as an ellipse or polygon, or may be an asymmetric shape. When the planar shape of the vibrating element 15 is not circular, the relative orientation between the planar shape and the planar shape of the plate-like element 11 may also be appropriately set.

(Laminated structure of plate-shaped element)
FIG. 4 is a cross-sectional view taken along line IV--IV of FIG. In this figure, the lower side of the paper is the patient 101 side.

The plate-like element 11 includes, for example, two or more layered (including plate-like, hereinafter the same) members extending along the plane direction (along the radiation surface 11a). Specifically, for example, the plate-like element 11 has an element substrate 19 having the vibrating element 15 and a cavity member 21 superimposed on the element substrate 19 . In addition, although not shown, the plate-like element 11 may have an adhesive or an insulating layer interposed between the element substrate 19 and the cavity member 21 .

The plate-shaped element 11 has the element substrate 19 side facing the patient 101 side, for example. The element substrate 19 vibrates due to the flexural deformation of the region serving as the vibration element 15 . This vibration is transmitted to the fluid positioned on the patient 101 side of the device substrate 19 to generate ultrasonic waves. The cavity member 21 has a plurality of cavities 21 c (openings, holes) individually overlapping the plurality of vibrating elements 15 of the element substrate 19 . The cavity member 21 contributes to defining the fixed end of the vibrating element 15 by the edge of the cavity 21c, for example, and thus contributes to adjusting the natural frequency (resonance frequency) of the vibrating element 15. As shown in FIG.

Due to the provision of the plurality of cavities 21c and the second electrodes 33 (individual electrodes) to be described later, the main surface (the widest surface of the plate; front and back) of the plate-like element 11 has irregularities and is flat. isn't it. As can be understood from this, when the plate-like element 11 is plate-like or flat plate-like, it is not strictly necessary to be a plate or a flat plate. For example, the plate-shaped element 11 has a length (thickness) in one of the three mutually orthogonal directions that is 1/3 or less, 1/5 or less, or 1/3 of the length in the other two directions. It may be regarded as plate-like when it is 10 or less or 1/20 or less. Further, for example, the plate-like element 11 may be regarded as a plate-like shape by having, as main constituent elements, layers (for example, 23, 25 and 27 to be described later) having a uniform thickness and forming a flat surface. Further, for example, the plate-like element 11 may be regarded as a flat plate when the apexes of the plurality of protrusions (or the deepest portions of the recesses) fit on the same plane on each of the two principal surfaces. Further, for example, when the arithmetic mean roughness of the unevenness of each main surface of the plate-shaped element 11 is 5% or less, 2% or less, or 1% or less with respect to the equivalent circle diameter obtained from the area of the plate-shaped element 11 It can be regarded as a flat plate.

(element substrate)
The element substrate 19 has a first surface 19a facing one side in the thickness direction and a second surface 19b facing the side opposite to the first surface 19a. In the illustrated example, the first surface 19a is the surface on the side of the patient 101 (from another point of view, the surface on the side opposite to the cavity member 21), and constitutes the radiation surface 11a. In this embodiment, the radiation surface 11a and the first surface 19a may be regarded as the same. The element substrate 19 is configured, for example, in a flat plate shape.

The element substrate 19 includes, for example, two or more layered members extending along its planar direction (along the first surface 19a). Specifically, for example, the element substrate 19 includes a vibration layer 23, a first conductor layer 25, a piezoelectric layer 27, and a second conductor layer 29 in order from the first surface 19a side. The first conductor layer 25 includes, for example, a first electrode 31 . The second conductor layer 29 includes, for example, multiple second electrodes 33 . The first electrode 31 and the second electrode 33 sandwich the piezoelectric layer 27 . By applying an AC voltage to the pair of electrodes, the vibrating element 15 of the element substrate 19 vibrates with flexural deformation. In addition to the illustrated layers, the element substrate 19 may include appropriate layers such as an insulating layer covering the second conductor layer 29, for example.

In the element substrate 19, the area regarded as the vibration element 15 may be defined as appropriate. In the description of the present embodiment, for the sake of convenience, the region of the element substrate 19 that overlaps with the cavity 21c (more strictly, the region that overlaps with the opening surface of the cavity 21c on the side of the element substrate 19) is defined as the vibration element 15. do. In addition, it is also possible to define a region overlapping with the second electrode 33 (individual electrode) as the vibration element 15 .

Each vibrating element 15 has a first element surface 15a forming part of the first surface 19a and a second element surface 15b forming part of the second surface 19b. The first surface 19 a is composed of the vibration layer 23 . The first element surface 15a is configured by a region of the first surface 19a that overlaps with the cavity 21c. The second surface 19 b is composed of the second conductor layer 29 and the area of the piezoelectric layer 27 exposed from the second conductor layer 29 . The second element surface 15b is constituted by the area of the second surface 19b exposed from the cavity 21c. Note that, for example, unlike the illustrated example, when an insulating layer covering the second conductor layer 29 is provided, the insulating layer may constitute the second surface 19b.

(vibration layer)
For example, the vibrating layer 23 spreads over the plurality of vibrating elements 15 (eg, substantially over the entire element substrate 19), and basically spreads without gaps. The thickness of the vibration layer 23 is, for example, generally constant. The vibration layer 23 contributes to, for example, restricting the deformation of the piezoelectric layer 27 in the planar direction and generating out-of-plane vibration, as will be described later.

The vibration layer 23 is made of, for example, an insulating material or a semiconductor material. The material of the vibration layer 23 may be an inorganic material or an organic material. More specifically, for example, the material of the vibration layer 23 may be a piezoelectric material that is the same as or different from the material of the piezoelectric layer 27 (described later). Also, for example, the material of the vibration layer 23 may be silicon (Si), silicon dioxide (SiO ₂ ), silicon nitride (SiN), or sapphire (Al ₂ O ₃ ). The vibration layer 23 may be configured by laminating a plurality of layers made of different materials.

(First conductor layer and first electrode)
The first conductor layer 25 includes only the first electrode 31 in the illustrated example. The first electrode 31 is configured as, for example, a common electrode. The common electrode, for example, has a width covering the plurality of vibrating elements 15 (a width covering substantially the entire element substrate 19) and basically spreads without gaps. The thickness of the first electrode 31 is, for example, generally constant. The first electrode 31 is, for example, a wiring (not shown) arranged on the opposite side of the bag 9 of the plate element 11 via a through conductor (not shown) penetrating the piezoelectric layer 27 (for example, a wiring member described later). 35) are electrically connected.

The material of the first conductor layer 25 may be, for example, a suitable metal. For example, gold (Au), silver (Ag), palladium (Pd), platinum (Pt), aluminum (Al), nickel (Ni), copper (Cu) or chromium (Cr), or alloys containing these are used. good. The first conductor layer 25 may be configured by laminating a plurality of layers made of different materials. Moreover, the material of the first conductor layer 25 may be obtained by firing a conductive paste containing the metal as described above. That is, the material of the first conductor layer 25 may contain an additive (an inorganic insulator from another point of view) such as glass powder and/or ceramic powder.

(Piezoelectric layer)
The piezoelectric layer 27 spreads, for example, over the plurality of vibration elements 15 (eg, over substantially the entire element substrate 19), and basically spreads without gaps. The thickness of the piezoelectric layer 27 is, for example, generally constant. However, unlike the illustrated example, the piezoelectric layer 27 may have a plurality of portions separated from each other and provided individually for the plurality of vibrating elements 15 .

The material of the piezoelectric layer 27 may be a single crystal, a polycrystal, an inorganic material, an organic material, or a ferroelectric. It may or may not be a pyroelectric body. Examples of inorganic materials include lead zirconate titanate-based materials and lead-free inorganic piezoelectric materials. Examples of lead-free inorganic piezoelectric materials include perovskite compound materials. Examples of organic materials include PVDF (polyvinylidene fluoride).

Further, the material of the piezoelectric layer 27 may be, for example, a piezoelectric ceramic plate (a sintered body from another point of view) or a piezoelectric thin film. A piezoelectric ceramic plate is a plate-like inorganic polycrystalline body composed of a plurality of piezoelectric crystal grains (and crystal grain boundaries), and is also called a piezoelectric ceramic plate. Crystal grains forming a piezoelectric ceramic plate usually have a small aspect ratio and are isotropically distributed. A piezoelectric thin film is a film-like inorganic single crystal, inorganic polycrystal, or organic material (polymer) having piezoelectric properties. A polycrystalline piezoelectric thin film is generally composed of columnar crystals extending in the thickness direction. Piezoelectric thin films usually have a high degree of orientation and thus have high piezoelectric properties.

In the piezoelectric layer 27, for example, at least in the region constituting the vibration element 15, the polarization axis (also referred to as the electric axis or the X-axis in a single crystal) is aligned with the thickness direction of the piezoelectric layer 27 (the first electrode 31 and the facing the second electrode 33). It should be noted that regions of the piezoelectric layer 27 other than the region forming the vibrating element 15 may or may not be polarized. In the case of being polarized, it may be polarized in the same direction as the region forming the vibrating element 15, or may be polarized in a different direction.

(Second conductor layer and second electrode)
The second conductor layer 29 may have, for example, wiring (not shown) connected to the plurality of second electrodes 33 in addition to the plurality of second electrodes 33 described above. The plurality of second electrodes 33 are, for example, other wirings (not shown) arranged on the opposite side of the bag 9 of the plate-like element 11 via lead electrodes (or wirings) included in the second conductor layer 29, which will be described later. (For example, a wiring member 35 to be described later) is electrically connected.

The plurality of second electrodes 33 are, for example, individual electrodes provided for each vibration element 15 . The term "individual electrode" as used herein means that a plurality of electrodes are separated from each other, and it is not necessary to be able to apply different potentials to each other. For example, two or more second electrodes 33 (for example, all second electrodes 33 within one plate-shaped element 11) may be electrically connected to each other. The connection may be made, for example, by wiring of the second conductor layer 29 (see FIG. 9, which will be described later), or by other means (for example, a wiring member 35, which will be described later). It should be noted that different potentials may be applied to the plurality of second electrodes 33 individually or to each group including two or more second electrodes 33 .

The planar shape and size of the second electrode 33 may be an appropriate shape. For example, the planar shape of the second electrode 33 may be similar or similar to the planar shape of the vibrating element 15 (opening shape of the cavity 21c), may have a different shape, or may be circular or elliptical. It may be a shape or a polygon. Further, for example, in a plan view, the outer edge of the second electrode 33 may be wholly located inside the opening edge of the cavity 21c, or may be substantially coincident with it. , the entirety of which may be located outside, or only a portion of which may coincide or be located inside. In this embodiment, the second electrode 33 is circular and located inside the opening edge of the circular cavity 21c.

The material of the second conductor layer 29 may be the same as or different from the material of the first conductor layer 25 . In either case, the description of the material of the first conductor layer 25 may be incorporated into the description of the material of the second conductor layer 29 .

(Operation of vibration element)
When an electric field is applied to the piezoelectric layer 27 sandwiched between the first electrode 31 and the second electrode 33 in the same direction as the polarization direction, the piezoelectric layer 27 contracts in the planar direction. Since this contraction is restricted by the vibrating layer 23, the vibrating element 15 bends (displaces) toward the vibrating layer 23 side (first surface 19a side) like a bimetal. Conversely, when an electric field is applied in a direction opposite to the polarization direction, the piezoelectric layer 27 expands in the planar direction. Since this extension is restricted by the vibrating layer 23, the vibrating element 15 bends (displaces) like a bimetal toward the side opposite to the vibrating layer 23 (the second surface 19b side).

Due to the displacement of the vibrating element 15 as described above, a pressure wave is formed in the medium (for example, fluid) surrounding the vibrating element 15 . Then, by inputting an electrical signal (driving signal) whose voltage changes with a predetermined waveform to the first electrode 31 and the second electrode 33, the waveform (frequency and amplitude from another point of view) of the electrical signal is reflected. Ultrasonic waves are generated.

In other words, the vibration due to bending deformation is a first-order mode out-of-plane vibration in which the vibration element 15 has a vibration antinode at the center of the planar view and a vibration node at the outer edge (for example, near the edge of the cavity 21c). (bending vibration). Regarding this vibration, the vibration element 15 is configured, for example, so that the resonance frequency is located in the ultrasonic frequency band. The resonance frequency is set by, for example, selecting the material of the layers constituting the vibrating element 15 (selecting the Young's modulus and density from another point of view), setting the diameter of the vibrating element 15 and the thickness of each layer (from another point of view setting of mass and bending stiffness), etc. The influence of the fluid surrounding the vibrating element 15 and the influence of the rigidity of the portion supporting the vibrating element 15 (for example, the cavity member 21) may be considered.

The electrical signal may be, for example, repeated application of a voltage to displace the vibrating element 15 toward the first surface 19a and application of a voltage to displace the vibrating element 15 toward the second surface 19b. That is, the electric signal may have a reversed polarity (positive or negative) (the direction of the voltage (electric field) alternates in the direction of the polarization axis of the piezoelectric layer 27). Further, for example, the electrical signal may be such that only voltage application for displacing the vibrating element 15 toward the first surface 19a side or only voltage application for displacing the vibrating element 15 toward the second surface 19b side may be repeated. In this case, ultrasonic waves are generated by repetition of bending and cancellation of bending by the restoring force.

Here, it is assumed that an insulating layer (not shown) is provided to cover the piezoelectric layer 27 from above the second conductor layer 29 . The insulating layer and the vibration layer 23 are common in that they overlap the piezoelectric layer 27, and the directions in which they overlap the piezoelectric layer 27 are opposite to each other. The insulating layer and the vibration layer 23 can be distinguished, for example, from the relationship between the expansion and contraction of the piezoelectric layer 27 and the direction of flexural deformation. Specifically, as described above, the vibration layer 23 restricts the expansion of the piezoelectric layer 27 in the plane direction, and bends the vibration element 15 toward the side opposite to the vibration layer 23 (the second surface 19b side). It has strength, and this is the same in the mode in which the insulating layer is provided. Therefore, the vibration layer 23 is the layer located on the side opposite to the side on which the vibration element 15 bends when the piezoelectric layer 27 expands. In addition, as described above, the vibration layer 23 has a strength that restricts the contraction of the piezoelectric layer 27 in the plane direction and bends the vibration element 15 toward the vibration layer 23 (first surface 19a). , this also applies to embodiments in which an insulating layer is provided. Therefore, the vibration layer 23 is the layer positioned on the side where the vibration element 15 bends when the piezoelectric layer 27 contracts. In the vibration layer 23, the strength (for example, the longitudinal elastic modulus related to compressive stress) for restricting the extension of the piezoelectric layer 27 in the plane direction and causing bending deformation toward the second surface 19b side, and the strength of the piezoelectric layer 27 The strength (for example, longitudinal elastic modulus with respect to tensile stress) for restricting contraction in the planar direction and causing bending deformation toward the first surface 19a side is generally the same. However, for example, there are materials that are not the same, and such materials may be used.

(Cavity member)
The cavity member 21 is, for example, a member having a constant thickness that covers the plurality of vibrating elements 15 when the cavity 21c is ignored. The width of the cavity member 21 may be the same as the width of the element substrate 19 (example in FIG. 4), or may be different.

Any material can be used for the cavity member 21. For example, it may be an insulating material, a semiconductor material, a conductive material, an inorganic material, or an organic material. , a piezoelectric material, or the same material as any layer in the element substrate 19 . Specifically, examples of the material of the cavity member 21 include metals, resins, and ceramics. Also, the cavity member 21 may be constructed from multiple materials or multiple layers. For example, the cavity member 21 may be configured by forming an insulating layer on a metal layer (including a metal plate) overlapping the element substrate 19, or may be configured by glass epoxy resin obtained by impregnating glass fiber with epoxy resin. may have been

The coefficient of linear expansion of the material of the cavity member 21 may be set larger than the coefficient of linear expansion of the material of the piezoelectric layer 27, for example. There are various combinations of the material of the cavity member 21 and the material of the piezoelectric layer 27 that satisfy such a relationship. For example, since a piezoelectric body usually has a small coefficient of linear expansion, the above relationship can be satisfied by forming the cavity member 21 from a metal (for example, stainless steel). However, unlike the above, the coefficient of linear expansion of the material of the cavity member 21 may be equal to or smaller than the coefficient of linear expansion of the material of the piezoelectric layer 27 .

The thermal conductivity of the material of the cavity member 21 may be, for example, higher than that of the substance filling the cavity 21c (in other words, the substance in contact with the second element surface 15b). When the substance that fills the cavity 21c is air, various materials can be used as the material of the cavity member 21 that satisfies the above requirements. Also, the thermal conductivity of the material of the cavity member 21 may be 100 times or more, or 500 times or more, that of the substance in the cavity 21c. In the case where the substance in the cavity 21c is air, the material of the cavity member 21 that satisfies the above magnification can be, for example, metal (for example, stainless steel).

The shape of the cavity 21c may be set appropriately. For example, the shape of the cavity 21c may be such that the cross section (the cross section parallel to the element substrate 19) has a constant shape regardless of the position of the cavity 21c in the penetrating direction (example shown). It may have a tapered surface that expands or contracts toward the 19 side. In the description of the present embodiment, the region of the element substrate 19 that overlaps the cavity 21c is the vibration element 15, so the above description of the planar shape of the vibration element 15 is incorporated into the description of the cross-sectional shape of the cavity 21c. may be

The depth of the cavity 21c (the length in the penetrating direction; from another point of view, the thickness of the cavity member 21) may be set as appropriate. For example, the depth of the cavity 21c may be 1/20 or more, 1/10 or more, 1/2 or more, or 1 time or more of the diameter of the cavity 21c (if it is not circular, for example, the circle equivalent diameter), It may be 10 times or less, 5 times or less, 1 time or less, 1/2 or less, or 1/10 or less, and the above lower limit and upper limit may be appropriately combined unless contradictory.

(support)
Returning to FIG. 2, the support 13 is shaped to hold the outer edges of the plurality of plate-shaped elements 11, for example. More specifically, the support 13 has, for example, a shape similar to the shape of the gap (the boundary from another point of view) between the adjacent plate-like elements 11 . In other words, the support 13 has a plurality of openings 13h that individually overlap the plate-like elements 11 . The plate-like element 11, for example, has its outer edge portion overlapped with the surface of the support 13 opposite to the patient 101, exposing the radiation surface 11a to the patient 101 side through the opening 13h.

The support 13 is composed of, for example, three portions that are substantially concentrically configured in plan view of the concave surface 7a. One is a grid portion 61 which is formed in a grid shape by forming a plurality of openings 13h and extends in a belt-like and annular shape over a region in which a plurality of plate-like elements 11 are arranged. The other is a brim-shaped edge 63 that flares outward from the outer edge of the grid portion 61 . The remaining one is a plate-shaped central portion 65 connected to the inner edge of the lattice portion 61 . The outer edges of the plurality of plate-like elements 11 are held by these portions.

Although not shown, the support 13 can be said to be constituted only by the lattice portion 61 by forming an opening in the central portion 65 or by reducing the diameter from the inner edge to the outer edge of the edge portion 63. may be assumed. As already described, the area where the central portion 65 is provided may be used as the arrangement area of the plate-like element 11 (in other words, the lattice portion 61 may extend toward the center).

The shape and area of the opening 13h may be set appropriately. For example, the shape of the opening 13h may be similar or similar to the shape of the outer edge of the plate element 11 (example shown), or may be different. Further, for example, the opening 13h may have a shape that decreases or expands in diameter from the front surface 13a on the side of the patient 101 toward the back surface 13b on the opposite side, or may have a shape that does not decrease in diameter or expand in diameter. There may be. Also, for example, the area of the opening 13h (for example, the minimum area when the diameter is reduced or expanded) may be 60% or more or 80% or more of the area of the plate-like element 11 .

The material of the support 13 may be any suitable material. For example, the material of support 13 may be metal, ceramic or resin, or a combination thereof. The metal may be stainless steel, for example. The thermal conductivity of the material of the support 13 may be greater than, equal to, or less than the thermal conductivity of the material of the cavity member 21 . The description of the thermal conductivity of the material of the cavity member 21 with respect to the thermal conductivity of the substance within the cavity 21c may be incorporated into the thermal conductivity of the material of the support 13 with respect to the thermal conductivity of the substance within the cavity 21c. The material of support 13 may be the same as or different from the material of cavity member 21 .

(Fixation structure between plate-like element and support)
FIG. 5 is a perspective view showing part of an example of the back surface 13b (the surface opposite to the affected area 103) of the support 13. As shown in FIG. In this figure, the support 13 is in a state before the plate element 11 is attached. 6 is a cross-sectional view showing a fixing structure between the plate-like element 11 and the support 13. As shown in FIG. This figure shows a cross section similar to that of FIG. 4, with details of the element substrate 19 omitted, and showing a slightly wider range than that of FIG. A pair of side surfaces 11s of the plate-like element 11 shown in this figure are a pair of legs 11f when viewed along line IV-IV in FIG. 3, but may be regarded as a combination of any two side surfaces. .

A concave portion 13r in which the plate-shaped element 11 is accommodated may be formed on the surface of the support 13 on which the plate-shaped element 11 is arranged (here, the back surface 13b on the side opposite to the patient 101). From another point of view, the support 13 has an overlapping portion 13e that overlaps the plate-like element 11 (more specifically, its outer edge portion in the present embodiment) in the thickness direction of the plate-like element 11, and the overlapping portion 13e. and a partition portion 13f protruding toward the plate-like element 11 side. Of course, the support 13 may have a shape that does not have such a concave portion 13r (partition portion 13f).

The partition part 13f is positioned between the plate-like elements 11 adjacent to each other. More specifically, in the illustrated example, the support 13 has partitions 13fa located between plate-like elements 11 adjacent to each other in the circumferential direction of the support 13 and partitions 13fa adjacent to each other in the radial direction of the support 13. It has a partition portion 13fb located between the plate-like elements 11 . The partition portion 13fa extends in the radial direction of the support 13, for example. The partition 13fb extends in the circumferential direction of the support 13, for example.

The concave portion 13 r has a shape and size that the plate-like element 11 fits therein, and may contribute to the positioning of the plate-like element 11 . The term "fitting" as used herein means, for example, that there is a gap (play) between the side surface of the plate-like element 11 and the wall surface of the recess 13r to allow the plate-like element 11 to move in the planar direction. include. This gap may contribute to, for example, placement of the first adhesive 37, which will be described later. The size of the gap is, for example, such that the entire outer edge of the plate-like element 11 is located outside the opening 13h even if the plate-like element 11 is moved to any position within the recess 13r in the plane direction. However, the concave portion 13r may be larger than the size that contributes to the positioning of the plate-like element 11 as described above.

The shape of the concave portion 13r viewed in its depth direction may be, for example, similar or similar to the planar shape of the plate element 11 and/or the shape of the opening 13h viewed in its opening direction. Therefore, the above description of the planar shape of the plate-like element 11 may be applied to the shape of the concave portion 13r. The shape of the concave portion 13r is such that the wall surface of the concave portion 13r contacts the side surface of the plate-shaped element 11 to position the plate-shaped element 11, and the first adhesive 37, which will be described later, is arranged apart from the side surface of the plate-shaped element 11. It may be a shape having a portion forming a gap to be formed. The wall surface of the recess 13r may be a vertical wall, or may be an inclined wall that reduces or expands the diameter of the recess 13r. The depth of the concave portion 13r may be smaller than, equal to, or larger than the thickness of the plate element 11. FIG.

The partition part 13f may have a shape that extends with a constant width and/or a constant height, a shape that extends while changing the width and/or height, or a shape that extends linearly. , or may be bent as appropriate. Moreover, the plurality of partitions 13fa may have the same shape, or may have different shapes. The same applies to the plurality of partitions 13fb.

FIG. 7 is an enlarged view of area VII of FIG.

As shown in this figure, the plate-like element 11 and the support 13 are adhered to each other by a first adhesive 37 adhered to the side surface 11s of the plate-like element 11 . The first adhesive 37 may adhere to the entire side surface of the plate-like element 11, or may adhere only to a portion thereof. Also, although not shown, an adhesive (not shown) may be placed between the radiation surface 11a of the plate-like element 11 and the overlapping portion 13e. The material of the first adhesive 37 may be an organic material, an inorganic material, an insulating material, or a conductive material. For example, the first adhesive 37 may be resin or metal.

(wiring member)
As shown in FIG. 7, the generator 7 has a wiring member 35 connected to the second electrode 33 . The wiring member 35 contributes to signal transmission between the plate-like element 11 and the device main body 5, for example.

The wiring member 35 is composed of, for example, a so-called insulated wire. That is, the wiring member 35 has a linear wiring conductor 35a and an insulator 35b covering the wiring conductor 35a. Materials for the wiring conductor 35a and the insulator 35b may be, for example, the same as those known in the art. Although not particularly shown, the wiring member 35 may be a cable having a protective coating that at least partially or entirely covers the insulator 35b. In this case, a plurality of insulated wires extending from a plurality of second electrodes 33 may be grouped together and covered with a protective coating. Also, part or all of the wiring member 35 may be configured by FPC (Flexible Printed Circuits).

In the illustrated example, the second conductor layer 29 has lead electrodes 34 extending from the second electrodes 33 for each second electrode 33 . 7, the boundary between the second electrode 33 and the extraction electrode 34 is indicated by a dotted line. The extraction electrode 34 is joined to the wiring member 35 (more specifically, its wiring conductor 35a) by a conductive bump 39. As shown in FIG. Thereby, the second electrode 33 and the wiring member 35 are connected. Note that, unlike the illustrated example, a portion of the second electrode 33 and the wiring member 35 may be connected without providing the extraction electrode 34 .

The specific shape and dimensions of the extraction electrode 34 may be set as appropriate. For example, the extraction electrode 34 has a shape that protrudes from the outer edge of the second electrode 33 in plan view. The width of the extraction electrode 34 (the length in the direction intersecting the projecting direction) is, for example, smaller than the diameter of the second electrode 33 (the length in the intersecting direction). Also, the area of the extraction electrode 34 is smaller than the area of the second electrode 33, for example. Also, the extraction electrode 34 is housed, for example, in the cavity 21c.

The bumps 39 are made of solder or conductive adhesive, for example. Solders include lead-free solders. The conductive adhesive is made of resin containing conductive particles, for example. The specific shape and dimensions of the bumps 39 may be set as appropriate.

The wiring member 35 extends from the inside of the cavity 21c to the outside of the cavity 21c. The end of the wiring member 35 opposite to the second electrode 33 is connected, for example, directly or indirectly to a connector (not shown) of the generator 7 (for example, indirectly via a circuit board (not shown)). It is connected to the. The connector is connected to the device main body 5 (more specifically, a cable 49 to be described later). A plurality of wiring members 35 to which the same potential is applied may be connected to each other by assembling a plurality of wiring conductors 35a in the process leading to the above circuit board or connector, or may be connected to each other. may be connected to each other via

A specific path along which the wiring member 35 extends may be set as appropriate. For example, the wiring member 35 may extend from the cavity 21c in the radial direction of the concave surface 7a, or may extend from the cavity 21c in the circumferential direction of the concave surface 7a. Moreover, the plurality of wiring members 35 extending from the plurality of cavities 21c of one plate-shaped element 11 may extend separately from one end connected to the second electrode 33 to the other end. However, they may be collected and extended from the middle by being covered with a protective coating. The plurality of wiring members 35 extending from the plurality of plate-shaped elements 11 may extend separately from each other from one end connected to the second electrode 33 to the other end, or may be covered with a protective coating. It may be collected and extended from the middle by being separated or the like.

The wiring member 35 may be joined to the cavity member 21 . Also, in this case, the position and length of the wiring member 35 to be joined, the joining method, and the like may be appropriately set.

In the illustrated example, the wiring member 35 is joined to the inner wall of the cavity 21c. In addition to or instead of this bonding position, for example, the wiring member 35 may be bonded to the surface of the cavity member 21 opposite to the element substrate 19 and/or to the side surface of the cavity member 21. may have been A plurality of wiring members 35 extending from a plurality of second electrodes 33 of one plate-like element 11 may be individually joined to the cavity member 21 at joints other than the inner wall of the cavity 21c. It may be joined to the cavity member 21 in a state where it is collected by being covered with a protective film or the like.

Also, in the illustrated example, the wiring member 35 is joined to the cavity member 21 with the second adhesive 71 . In addition, for example, although not shown, the wiring member 35 is joined to the cavity member 21 by melting a part of the wiring member 35 (for example, the insulator 35b or a protective coating not shown covering it). may be In the illustrated example, the second adhesive 71 is interposed between the wiring member 35 and the cavity member 21 to bond them together. In addition to or instead of such adhesion, the second adhesive 71 may adhere the wiring member 35 to the cavity member 21 by covering the cavity member 21 from above the wiring member 35 .

The material of the second adhesive 71 may be an organic material, an inorganic material, an insulating material, or a conductive material. For example, the second adhesive 71 may be resin or metal. The second adhesive 71 may be the same material as the first adhesive 37, or may be a different material, and may be connected to or separated from the first adhesive 37. good too. If the second adhesive 71 is made of the same material as the first adhesive 37 and the two are connected, they may be supplied together during the manufacturing process.

The wiring member 35 may be bonded to the support 13 in addition to or instead of bonding to the cavity member 21 . Also, in this case, the position and length of the wiring member 35 to be joined, the joining method, and the like may be appropriately set.

In the illustrated example, the wiring member 35 is joined to the top surface of the partition portion 13f. In addition to or instead of this joining position, for example, the wiring member 35 may be joined to the inner wall of the partition portion 13f, or may be joined to the surface of the central portion 65 opposite to the patient 101. and/or may be bonded to the side of edge 63 opposite patient 101 . The plurality of wiring members 35 extending from the plurality of second electrodes 33 of one plate-shaped element 11 and/or the plurality of wiring members 35 extending from the plurality of plate-shaped elements 11 are individually joined to the support 13 . Alternatively, they may be joined to the support 13 in a grouped state, such as by being covered with a protective coating.

Also, in the illustrated example, the wiring member 35 is bonded to the support 13 with a third adhesive 73 . In addition, for example, although not shown, the wiring member 35 is joined to the support 13 by melting a part of the wiring member 35 (for example, the insulator 35b or a protective coating not shown covering it). may be In the illustrated example, the third adhesive 73 is interposed between the wiring member 35 and the support 13 to bond them together. In addition to or instead of such adhesion, the third adhesive 73 may adhere the wiring member 35 to the support 13 by covering the support 13 from above the wiring member 35 .

The material of the third adhesive 73 may be an organic material, an inorganic material, an insulating material, or a conductive material. For example, the third adhesive 73 may be resin or metal. The third adhesive 73 may be the same material as the first adhesive 37 and/or the second adhesive 71, or may be a different material. 2 may be connected with the adhesive 71 or may be separated. If the third adhesive 73 is made of the same material as the first adhesive 37 and/or the second adhesive 71 and they are connected, they may be supplied together during the manufacturing process.

Although not particularly shown, the surface of the element substrate 19 on the cavity member 21 side may have a region exposed from the cavity member 21 at an appropriate position (for example, near the outer edge). A terminal connected to the first electrode 31 via a penetrating conductor penetrating the piezoelectric layer 27 may be provided in the region. A wiring member 35 may be connected to this terminal in the same manner as the extraction electrode 34 . That is, the wiring member 35 may be electrically connected to the first electrode 31 . As for the wiring member 35 connected to the first electrode 31, the description of the wiring member 35 connected to the second electrode 33 may be used as appropriate.

For example, the wiring member 35 connected to the first electrode 31 may also be joined to the cavity member 21 and/or the support 13 . The joining position and joining method are arbitrary. A plurality of wiring members 35 connected to the first electrodes 31 of the plurality of plate-shaped elements 11 are separated from each other between the plurality of plate-shaped elements 11 and a circuit board (not shown) or a connector (not shown). It may be extended, or it may be collected and extended by being covered with a protective film along the way. Also, the wiring member 35 connected to the first electrode 31 and the wiring member 35 connected to the second electrode 33 may extend separately from each other, or may be covered with a protective film along the way. may be grouped together and extended.

(Example of dimensions, etc.)
As already described, in the radiation device 3, the frequency of the ultrasonic waves, the dimensions of each part of the radiation device 3, and the like may be appropriately set. An example is given below. The frequency of the ultrasonic waves generated by the radiation instrument 3 may be 0.5 MHz or more and 2 MHz or less. The diameter of the generating portion 7 (diameter on a plane including the outer edge of the concave surface 7a) may be 50 mm or more and 200 mm or less. The equivalent circle diameter of the plate-shaped element 11 or the length of one side of the trapezoid may be 5 mm or more and 20 mm or less. The equivalent circle diameter of the vibration element 15 may be 0.2 mm or more and 2 mm or less. The thickness of the element substrate 19 may be 50 μm or more and 200 μm or less. Each of the thickness of the vibration layer 23 and the thickness of the piezoelectric layer 27 may be 20 μm or more and 100 μm or less within a range consistent with the thickness of the element substrate 19 . The thickness of each of the first conductor layer 25 (first electrode 31) and the second conductor layer 29 (second electrode 33) may be 0.05 μm or more and 5 μm or less. The thickness of the support 13 may be greater than or equal to the thickness of the element substrate 19 .

(bag)
Returning to FIG. 1, the shape, size and material of the bag 9 may be set appropriately. For example, the shape of the bag 9 may be a shape that bulges outward as a whole, such as a sphere. In addition, for example, when the radiation device 3 is intended for a specific part of the human body, it should have a shape having convex parts and/or concave parts corresponding to the concave parts and/or convex parts of the specific part. good too.

The material of the bag 9 has at least the property of impermeability to the liquid LQ (so-called water impermeability) and flexibility. Moreover, the material of the bag 9 may be an elastic body. For example, as the material of the bag 9, thermosetting elastomer (so-called rubber), thermoplastic elastomer (narrowly defined elastomer), and resin not containing these elastomers (narrowly defined resin, but having flexibility) are used. you can Thermosetting elastomers include vulcanized rubber (rubber in a narrow sense) and thermosetting resin-based elastomers.

As described above, the bag 9 contains the liquid LQ at least when the ultrasonic device 1 is used. The bag 9 (radiation device 3) may be, for example, filled with the liquid LQ during distribution, or may be filled with the liquid LQ during use. Further, the bag 9 (radiation device 3) may or may not have an openable/closable port for supplying (and/or discharging) the liquid LQ into the bag 9, for example. can be anything. Various known structures may be used for the opening/closing structure of the port.

The bag 9 has an opening 9a on the generator 7 side. A portion of the generator 7 including the concave surface 7a is in contact with the liquid LQ in the bag 9 through the opening 9a. On the other hand, a portion of the generator 7 including the surface opposite to the concave surface 7a is not in contact with the liquid LQ of the bag 9, but is in contact with the gas (for example, air) around the radiation device 3. FIG. Therefore, in the vibrating element 15, the first element surface 15a on the patient 101 side is in contact with the liquid LQ, and the second element surface 15b on the opposite side is in contact with gas (for example, air). The structure for reducing the leakage of the liquid LQ from between the edge of the opening 9a and the generating portion 7 may be made as appropriate.

The relationship between the physical property values of the substance in contact with the first element surface 15a (for example, air in this embodiment) and the physical property value of the substance in contact with the second element surface 15b (liquid LQ in this embodiment) may be set as appropriate. . For example, the thermal conductivity of the substance in contact with the second element surface 15b (the substance that fills the cavity 21c from another point of view) is the thermal conductivity of the substance in contact with the first element surface 15a (the substance in contact with the vibration layer 23 from another point of view). rate.

(device body)
The apparatus main body 5 includes, for example, a drive control section 41 for driving and controlling the radiation instrument 3, a moving section 43 for moving the radiation instrument 3, an input section 45 for receiving user's input operation, and presenting information to the user. and an output unit 47 for outputting.

The drive controller 41 is connected to the generator 7 via a cable 49, for example. The drive control unit 41 has a drive unit 51 that inputs a signal related to the generation of ultrasonic waves to the generation unit 7 and a control unit 53 that controls the drive unit 51 .

Regarding the operation of inputting drive signals to the first electrode 31 and the second electrode 33 to generate ultrasonic waves, the role sharing between the driving section 51 and the electric circuit in the generating section 7 may be appropriately set. Here, for the sake of simplicity of explanation, the electric circuit of the generating section 7 will be explained as having a role of only transmitting the signal from the driving section 51 to the first electrode 31 and the second electrode 33 . However, at least part of the functions of the driving unit 51 described below may be provided in the generating unit 7 .

For example, the drive unit 51 converts power from a commercial power supply or the like into AC power having a waveform (for example, frequency and voltage (amplitude)) specified by the control unit 53 and inputs the power to the first electrode 31 and the second electrode 33. do. The drive signal is AC power having a frequency approximately equal to that of the ultrasonic waves intended to be emitted and having a voltage corresponding to the amplitude of the ultrasonic waves intended to be emitted. The drive signal may be of any suitable shape, such as a square wave (pulse), sine wave, triangular wave or sawtooth wave.

The control unit 53 includes a computer including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an external storage device, etc., although not shown. Functional units that perform various controls are constructed by the CPU executing programs stored in the ROM and/or the external storage device. For example, based on the signal from the input unit 45, the control unit 53 sets the waveform (e.g., frequency and voltage (amplitude)) of the drive signal output from the drive unit 51, and also controls the waveform of the drive signal from the drive unit 51. Controls the start and stop of output.

The moving unit 43 includes, for example, although not shown, a holding mechanism that holds the radiation instrument 3 and a drive source (for example, a motor) that imparts power to the holding mechanism to move the radiation instrument 3. ing. Such a moving part 43 may be configured similarly to, for example, an articulated robot, a SCARA robot, or an orthogonal robot. The moving unit 43 relatively moves the radiation instrument 3 with respect to the patient 101 based on the control command from the control unit 53 . This relative movement may include, for example, movement to bring the radiation instrument 3 closer to the patient 101 and/or movement for positioning to locate the focal point of the ultrasound at the affected area 103 . The control unit 53 controls the moving unit 43 based on a signal from the input unit 45 and/or based on a signal from a sensor (not shown) that specifies the position of the affected area 103 or the like. It should be noted that the moving part 43 may not be provided, or the driving source of the moving part 43 may not be provided, and the radiation instrument 3 may be transported and positioned by human power.

The input unit 45 includes, for example, a keyboard, mouse, mechanical switch and/or touch panel. The input unit 45 receives, for example, an operation for setting the frequency and amplitude of the ultrasonic waves emitted from the emitting instrument 3 and an operation for instructing the start and stop of the emission of ultrasonic waves. The output unit 47 includes, for example, a display device and/or a speaker. The output unit 47 presents, for example, information such as the frequency and amplitude of the ultrasonic waves set at the present time.

As described above, in this embodiment, the ultrasonic wave emitting instrument 3 has the element substrate 19 and the cavity member 21 . The element substrate 19 has a first surface 19a facing one side in the thickness direction and a second surface 19b facing the other side in the thickness direction. has a plurality of vibrating elements 15 that produce vibrations that generate ultrasonic waves. The cavity member 21 has a plurality of cavities 21 c individually overlapping the plurality of vibrating elements 15 . Each of the vibration elements 15 has a piezoelectric layer 27 , a first electrode 31 , a second electrode 33 and a vibration layer 23 . The first electrode 31 overlaps the piezoelectric layer 27 on the first surface 19a side. The second electrode 33 overlaps the piezoelectric layer 27 on the second surface 19b side. The vibration layer 23 overlaps the first electrode 31 on the first surface 19a side. The vibration layer 23 regulates the extension along the first surface 19a of the piezoelectric layer 27 to bend the vibration element 15 toward the second surface 19b, and also regulates the contraction of the piezoelectric layer 27 along the first surface 19a. and at least one of the strength to bend the vibrating element 15 toward the first surface 19a. The cavity member 21 overlaps the element substrate 19 on the second surface 19b side.

Therefore, for example, interference between the vibrating elements 15 can be reduced. Specifically, for example, it is as follows. In the element substrate 19 , bending deformation of the vibrating element 15 occurs due to extension and/or contraction (expansion and contraction) of the piezoelectric layer 27 in the planar direction. When the cavity member 21 is bonded to the element substrate 19 on the piezoelectric layer 27 side, the cavity member 21 is bonded to the element substrate 19 on the vibration layer 23 side. It is easy to reduce the interference related to the expansion and contraction. As a result, it is possible to reduce interference between the vibration elements 15 with respect to vibrations associated with the generation of ultrasonic waves. By reducing the interference between the vibrating elements 15, for example, loss of vibration energy can be reduced. Also, for example, it is possible to reduce the probability of deviation in the frequency of the ultrasonic waves.

Moreover, in this embodiment, the radiation instrument 3 has a plurality of plate-like elements 11 and a support 13 . Each of the plate-like elements 11 has an element substrate 19 and a cavity member 21 . The support 13 holds the plate-like elements 11 in such a manner that the plurality of first surfaces 19a or the plurality of second surfaces 19b (the former in this embodiment) face the same position (affected area 103) from different directions. are doing.

In this case, for example, the concave surface 7a that radiates ultrasonic waves is not formed integrally, but is composed of a plurality of plate-like elements 11. As shown in FIG. As a result, for example, the method of manufacturing the generating portion 7 can be simplified. For example, when the plate-like element 11 is flat, the plate-like element 11 can be produced by a method similar to that for producing a normal circuit board or the like.

Further, for example, since each plate-shaped element 11 has a plurality of vibration elements 15, the degree of freedom in designing the plate-shaped element 11 is improved. Specifically, for example, it is as follows. In the case where the plate-like element 11 as a whole vibrates, the resonance frequency of the plate-like element 11 decreases as the area of the plate-like element 11 increases. Therefore, the size of the plate-like element 11 is limited from the viewpoint of bringing the resonance frequency of the predetermined vibration mode of the plate-like element 11 closer to the desired drive frequency of the ultrasonic wave. On the other hand, in the present embodiment, the resonance frequency of the vibrating element 15 can be brought close to the driving frequency of the ultrasonic waves, so the area of the plate-like element 11 can be increased.

Further, in this embodiment, the plate-like element 11 is flat.

In this case, for example, as described above, the method of manufacturing the generating portion 7 is facilitated, such as by applying the method of manufacturing a normal circuit board to the method of manufacturing the plate-shaped element 11 . Also, for example, ultrasonic waves can be applied to a relatively wide focal region.

FIGS. 8(a) and 8(b) are schematic diagrams for explaining the effect of irradiating the above-described wide focal region with ultrasonic waves. Specifically, FIGS. 8A and 8B schematically show how ultrasonic waves are focused in this embodiment and another example.

First, as another example, consider an element 151 having a curved radiation surface 151a as shown in FIG. 8(b). The radiation surface 151a is composed of, for example, one plate-like lens member, and a plurality of vibration elements 15 (strictly speaking, equivalent to the vibration elements 15; not shown here) behind the lens member. arrayed. Then, the lens member focuses the ultrasonic waves generated by the plurality of transducer elements 15 to the focal point P1. The focus P1 is theoretically a point, and the ultrasonic waves are focused in a relatively narrow range.

On the other hand, as shown in FIG. 8A, the ultrasonic waves emitted from the plate-like element 11 ideally reach the focusing region R1 with the same width (beam width) emitted from the plate-like element 11. be irradiated. Then, the ultrasonic waves of the plurality of plate-like elements 11 are focused. Therefore, the focused region R1 theoretically becomes a region having a width approximately equal to the width of the ultrasonic waves emitted from the plate-like element 11. FIG. Within the width of this convergence region R1, the intensity of the ultrasonic waves is approximately the same. Depending on the size of the affected area 103, the type of disease, etc., formation of such a focused region R1 is efficient and/or safe.

Here, as already described, in the present embodiment, each plate-shaped element 11 has a plurality of transducer elements 15. Therefore, the area of the plate-shaped element 11 is determined by the frequency of ultrasonic waves (from another point of view, It can be set separately from the resonance frequency of the vibrating element 15). As a result, for example, it is easy to obtain a combination of a desired ultrasonic frequency and a desired beam width (area of the plate-like element 11).

Further, in the present embodiment, among the plurality of first surfaces 19a and the plurality of second surfaces 19b, the plurality of first surfaces face the same position (convergence region R1) as the radiation surface 11a.

In this case, for example, compared to a mode in which the plurality of second surfaces 19b face the same position (this mode may also be included in the technology according to the present disclosure), the configuration is easier to simplify. For example, contrary to the present embodiment, when the second surface 19b faces the affected area 103, the liquid LQ is positioned inside the cavity 21c. Therefore, for example, it becomes more necessary to cover the electrode (here, the second electrode 33) exposed in the cavity 21c with an insulating film. On the other hand, when the first surface 19a faces the affected area 103 as in the present embodiment, the liquid LQ contacts the vibrating layer 23, so the need to cover the second electrode 33 with an insulating film is reduced, or the necessity thereof is reduced. It is possible to improve the degree of freedom regarding the material and thickness of such an insulating film. Contrary to the present embodiment, when the second surface 19b faces the affected part 103, for example, the cavity 21c can be used to adjust the directivity of the ultrasonic waves.

Further, in this embodiment, the piezoelectric layer 27, the first electrode 31, and the vibration layer 23 each extend over the plurality of vibration elements 15 without gaps. Also, the plurality of second electrodes 33 are individually positioned on the plurality of vibrating elements 15 at intervals.

In this case, for example, at least one of the piezoelectric layer 27, the first electrode 31, and the vibration layer 23 is provided for each vibration element 15 (this mode may also be included in the technology according to the present disclosure). In comparison, since interference between the vibrating elements 15 is more likely to occur, the effect described above is effective in reducing the interference. Further, for example, the piezoelectric layer 27, the first electrode 31, and the vibration layer 23 have a simple configuration, and the rigidity of the element substrate 19 can be easily secured. On the other hand, for example, by using the plurality of second electrodes 33 as individual electrodes, it is possible to reduce the interference between the transducer elements 15 and improve the accuracy of the frequency of the ultrasonic waves. Contrary to the embodiment, the first electrode 31 positioned between the piezoelectric layer 27 and the vibration layer 23 is used as an individual electrode, and the side of the piezoelectric layer 27 opposite to the vibration layer 23 (the side opposite to the patient 101). In comparison with the aspect (this aspect may also be included in the technology according to the present disclosure) in which the second electrode 33 located at the position is a common electrode, for example, the first electrode 31 and the second electrode 33 are connected to the wiring member 35 It is easy to simplify the arrangement of conductors in the element substrate 19 for the purpose. Furthermore, since the second surface 19b (second electrode 33 side) is on the side opposite to the patient 101, for example, heat can be released to the side opposite to the patient 101 by the wiring member 35 for each individual electrode.

Further, in the present embodiment, the coefficient of linear expansion of the cavity member 21 may be made larger than the coefficient of linear expansion of the piezoelectric layer 27 .

In this case, for example, in a mode in which the first surface 19a (piezoelectric layer 27 side) faces the focusing region R1 (affected area 103), the probability of deterioration in the focusing performance of ultrasonic waves can be reduced. Specifically, for example, consider heating and bonding the cavity member 21 and the piezoelectric layer 27 . For example, consider joining them with a thermosetting resin. In this case, when the temperature drops after bonding, the piezoelectric layer 27 receives compressive force from the cavity member 21 as a whole, but the vibrating element 15 receives tensile force from the portion between the cavities 21c of the cavity member 21. . As a result, the vibrating element 15 bends so that the first element surface 15a side becomes concave. As a result, the ultrasonic waves radiated from the first element surface 15a can be focused.

Further, in the present embodiment, the thermal conductivity of the cavity member 21 may be made higher than the thermal conductivity of the substance (for example, air) that fills the cavity 21c.

In this case, for example, the heat of the second electrode 33 and the wiring member 35 positioned inside the cavity 21c can be easily released to the outside of the cavity 21c. The heat of the second electrode 33 and the wiring member 35 is generated, for example, by a current of several mA to several tens of mA flowing through them. By allowing heat to escape from the second electrode 33 and the wiring member 35 and reducing their temperature rise, for example, the probability that their resistance values will rise can be reduced. As a result, it is possible to reduce the probability that power consumption will increase and/or reduce the probability that sound pressure will decrease.

Further, in the present embodiment, the thermal conductivity of the substance filling the cavity 21c is smaller than the thermal conductivity of the substance (liquid LQ in this embodiment) in contact with the plurality of vibrating elements 15 from the first surface 19a side. may be

In this case, for example, the heat dissipation in the cavity 21c is relatively low, and the effect of improving the heat dissipation by the cavity member 21 described above is effective.

Further, in this embodiment, the cavity member 21 and the support 13 are joined together.

As described above, in the present embodiment, since the thermal conductivity of the cavity member 21 is relatively high, heat dissipation in the cavity 21c is improved, and various effects are achieved. Since the cavity member 21 and the support 13 are bonded together, the heat transmitted through the cavity member 21 can be released to the support 13, thereby further improving the heat dissipation in the cavity 21c. improves the effectiveness of

Moreover, in this embodiment, the radiation instrument 3 has a wiring member 35 . The wiring member 35 includes at least one of a wiring conductor 35 a connected to the first electrode 31 and a wiring conductor 35 a connected to the second electrode 33 , and is joined to the support 13 .

In this case, for example, the heat generated in the first electrode 31 , the second electrode 33 and/or the wiring conductor 35a can be easily released from the wiring member 35 to the support 13 . As a result, for example, as described above, the resistance value of the first electrode 31, the second electrode 33 and/or the wiring conductor 35a can be reduced, thereby reducing power consumption and improving sound pressure.

(Modification)
FIG. 9A is a schematic plan view showing a modification of the connection structure of the plurality of second electrodes 33 (separate electrodes from another point of view). FIG. 9(b) is a sectional view taken along line IX-IX of FIG. 9(a).

As mentioned in the description of the embodiment, the plurality of second electrodes 33 included in the second conductor layer 29 may be connected to each other by the plurality of layered wirings 75 included in the second conductor layer 29. ) and FIG. 9(b) show an example of such a structure. The positions of the plurality of layered wirings 75 and the connection relationship of the plurality of second electrodes 33 may be appropriately set. In the illustrated example, the plurality of layered wirings 75 connect in series the plurality of second electrodes 33 arranged in the vertical direction of the paper, and connect the columns including the serially connected second electrodes 33 to each other. connected in parallel. These mutually connected second electrodes 33 are connected to pad-shaped terminals 77 included in the second conductor layer 29 .

Although not particularly shown, the cavity member 21 is adhered to the piezoelectric layer 27 by, for example, an adhesive (not shown) that is thicker than the thickness of the layered wiring 75. The cavity member 21 is attached directly to the layered wiring 75 or via the adhesive. It overlaps the layered wiring 75 indirectly. However, a concave groove for accommodating the layered wiring 75 may be formed on the surface of the cavity member 21 on the piezoelectric layer 27 side.

The cavity member 21 has, for example, a space 21d (for example, a notch or opening) that does not overlap the element substrate 19 so as to expose the terminals 77. As shown in FIG. In the space 21d, the terminal 77 and the wiring conductor 35a of the wiring member 35 are joined by the bump 39 as in the cavity 21c. 7, the wiring member 35 is not joined to the wall surface of the cavity 21d, but is joined to the surface of the cavity member 21 opposite to the piezoelectric layer 27. As shown in FIG. However, as mentioned in the description of the embodiment, the wiring member 35 may be joined to the wall surface of the cavity 21d in addition to or instead of the above surface.

As is clear from this modification, the plurality of individual electrodes (here, the second electrodes 33) need not be completely separated from each other. A plurality of individual electrodes may be spaced apart from each other. In other words, the plurality of individual electrodes may have a non-placement region of the conductor layer (here, the second conductor layer 29) sandwiched therebetween. For example, in the illustrated example, a plurality of individual electrodes arranged in the vertical direction of the paper are spaced apart by an interval S1. A plurality of individual electrodes arranged in the left-right direction of the paper are spaced apart by an interval S2.

The technology according to the present disclosure is not limited to the above embodiments, and may be implemented in various forms.

For example, ultrasound emitting instruments and ultrasound devices are not limited to those used for therapy. For example, it may be used in an ultrasonic diagnostic apparatus that captures a cross-sectional secondary image of a patient. Also, for example, it may be used for application of energy and/or distance measurement in various fields, not limited to the medical field.

A plate-like element may be used alone. In other words, no support may be provided to hold the plurality of plate-like elements. Also, the plate-like element may be curved rather than flat. In this case, the ultrasound emitting instrument may be intended to focus the ultrasound to a focal point as in FIG. 8(b).

In the case where a plurality of plate-shaped elements are provided, the plurality of plate-shaped elements are arranged such that the radiation surfaces for emitting ultrasonic waves are directed to the same position (focusing area) (in another point of view, the radiation surfaces are directed in different directions). facing). For example, a plurality of plate-like elements may be arranged so that their radiation surfaces face each other in the same direction.

Moreover, when the plurality of radiation surfaces are directed to the same position, the plurality of plate-like elements need not be arranged to form a concave surface. For example, the plate-like elements may be arranged in the same plane, like the slats of a blind, and arranged at different angles to said plane so as to face a common focal area.

In an embodiment, the support had openings 13h exposing the plurality of vibrating elements. Instead of such an opening 13h, a plurality of openings individually overlapping the plurality of vibrating elements may be provided. In this case, the support and the plate-shaped element may be adhered around the plurality of openings.

In the embodiment, the plate-shaped element is superimposed on the side of the support facing away from the patient, but it may be superimposed on the side of the support facing the patient, or have such an overlap. It doesn't have to be. Moreover, the plate-shaped element may face either the cavity member side or the element substrate side with respect to the support.

DESCRIPTION OF SYMBOLS 1... Ultrasonic apparatus, 3... Ultrasonic radiation apparatus, 11... Plate-shaped element, 19... Element substrate, 19a... First surface, 19b... Second surface, 15... Vibration element, 21... Cavity member, 23... Vibration layer , 27... Piezoelectric layer material, 31... First electrode, 33... Second electrode.

Claims (10)

It has a first surface facing one side in the thickness direction and a second surface facing the other side in the thickness direction, and vibration that generates ultrasonic waves at a plurality of positions in the direction along the first surface When seen from above, the plurality of vibration elements are not located on the entire surface of the first surface, but are located in a region on the center side of the first surface. an element substrate having
a cavity member having a plurality of cavities that individually overlap the plurality of vibrating elements, the edges of each cavity surrounding each vibrating element in plan view and defining a fixed end of each vibrating element; and,
and
Each of the plurality of vibration elements,
a piezoelectric layer;
a first electrode overlapping the piezoelectric layer on the first surface side;
a second electrode overlapping the piezoelectric layer on the second surface side;
and a vibration layer overlapping the first electrode with respect to the first surface side,
The vibration layer has a strength that restricts the expansion of the piezoelectric layer along the first surface to bend the vibration element toward the second surface, and restricts the contraction of the piezoelectric layer along the first surface. and has at least one strength to bend the vibration element toward the first surface,
The ultrasonic emitting device, wherein the cavity member overlaps the element substrate on the second surface side. a plurality of plate-like elements each having the element substrate and the cavity member;
a support holding the plurality of plate-like elements in an arrangement in which the plurality of first surfaces or the plurality of second surfaces are directed to the same position from different directions;
The ultrasound emitting instrument of claim 1, comprising: 3. The ultrasonic wave emitting instrument according to claim 2, wherein said plurality of first surfaces among said plurality of first surfaces and said plurality of second surfaces are directed to said same position. each of the piezoelectric layer, the first electrode, and the vibration layer spreads over the plurality of vibration elements without gaps;
4. The ultrasonic emission instrument according to claim 3, wherein a plurality of said second electrodes are spaced apart from each other and individually located on said plurality of transducer elements. 5. The ultrasonic wave emitting device according to claim 3, wherein the linear expansion coefficient of the cavity member is higher than that of the piezoelectric layer. The ultrasonic wave emitting instrument according to any one of claims 3 to 5, wherein thermal conductivity of said cavity member is higher than thermal conductivity of a substance filling said cavity. 7. The ultrasonic wave emitting instrument according to claim 6, wherein the thermal conductivity of a substance filling said cavity is lower than that of a substance in contact with said plurality of vibrating elements from said first surface side. The ultrasonic emission instrument according to claim 6 or 7, wherein the cavity member and the support are joined together. A wiring member including at least one of a wiring conductor connected to the first electrode and a wiring conductor connected to the second electrode, and further comprising a wiring member joined to the support. The ultrasonic emission instrument according to any one of 1. An ultrasonic wave emitting instrument according to any one of claims 1 to 9;
a drive control unit that supplies AC power having a frequency within an ultrasonic frequency band to the plate-shaped element;
An ultrasound device having a

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