JP2010213766A - Ultrasonic probe and ultrasonic diagnosis apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe receiving high-order harmonics with high sensitivity, and an ultrasonic diagnosis apparatus including an ultrasonic probe capable of receiving high-order harmonics with high sensitivity. <P>SOLUTION: In the ultrasonic probe, at least one transmit element layer for transmitting ultrasonic waves where electrodes are formed on both surfaces opposite to each other, respectively, in the thickness direction, at least one receiving element layer for receiving ultrasonic waves where electrodes are formed on both surfaces opposite to each other, respectively, in the thickness direction, and at least one matching layer for attaining matched acoustic impedance are stacked in order to point to the direction of transmitting ultrasonic waves. In the ultrasonic probe, the surface for transmitting ultrasonic waves of the transmit element layer has a recessed shape and the uppermost matching layer is formed of polymethylpentene. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus.

  An ultrasonic diagnostic apparatus is a medical imaging device that obtains a tomographic image of soft tissue in a living body in a minimally invasive manner from the body surface by an ultrasonic pulse reflection method. Compared to other medical imaging equipment, this ultrasound diagnostic device has features such as being smaller and cheaper, without exposure to X-rays, etc., being highly safe, and capable of blood flow imaging by applying the Doppler effect. Yes. Therefore, it is widely used in the circulatory system (cardiac coronary artery), digestive system (gastrointestinal), internal medicine system (liver, pancreas, spleen), urology system (kidney, bladder), and obstetrics and gynecology.

  In order to perform transmission and reception of ultrasonic waves with high sensitivity and high resolution, an ultrasonic probe used in such a medical ultrasonic diagnostic apparatus is generally a piezoelectric element made of lead zirconate titanate. used. In this case, as the vibration mode of the transmitting piezoelectric element, a single type probe or an array type probe in which a plurality of probes are two-dimensionally arranged is often used. Since the array type can obtain a fine image, it is widely used as a medical image for a diagnostic examination.

  On the other hand, harmonic imaging diagnosis using harmonic signals is becoming a standard diagnosis method because a clear diagnosis image that cannot be obtained by conventional B-mode diagnosis is obtained.

  Harmonic imaging has many advantages compared to the fundamental wave as follows.

  1. The S / N ratio is good and the contrast resolution is good because the side lobe level is small.

  2. The higher the frequency, the narrower the beam width and the better the lateral resolution.

  3. Multiple reflections do not occur because the sound pressure is small and the fluctuation in sound pressure is small at short distances.

  4). Attenuation beyond the focal point is similar to that of the fundamental wave, and the deep velocity can be increased compared to ultrasonic waves with the harmonic frequency as the fundamental wave.

  Etc.

  As a specific structure of an array-type ultrasonic probe used for harmonic imaging, an array-type transducer that separates the operations during transmission and reception of ultrasonic waves, with the transmission and reception piezoelectric transducers separate. An ultrasound probe has been proposed.

  It is desirable that the receiving piezoelectric vibrator used in such an array type ultrasonic probe can receive a harmonic signal with high sensitivity. However, since the transmission / reception frequency of a piezoelectric element made of lead zirconate titanate or the like depends on the thickness of the piezoelectric element, it is necessary to process the piezoelectric element in a smaller size as the receiving frequency becomes higher, and it is difficult to manufacture. there were.

  In order to solve such a problem, a piezoelectric element for transmission and a sheet-like piezoelectric element for reception having a single layer or laminated structure of sheet-like piezoelectric ceramics are made into a single layer or laminated, and separate transmission and reception piezoelectric elements And a method of obtaining a highly sensitive ultrasonic probe by using a highly sensitive organic piezoelectric element material for reception (see Patent Documents 1, 2, and 3).

  On the other hand, an acoustic lens is conventionally used in an ultrasonic probe to improve resolution by converging an ultrasonic beam. Since the acoustic lens is in close contact with a living body, a material that is close to the acoustic impedance of the living body and has a small attenuation factor at the frequency to be used is required in order to minimize reflection of ultrasonic waves from the living body.

  Conventionally, silicon rubber has been mainly used as a material for such an acoustic lens. However, since silicon rubber has a large propagation loss of ultrasonic waves, it is not suitable for high frequency or wide band.

Therefore, the ultrasonic receiving surface is made concave, and the material is made of ethylene-vinyl acetate copolymer resin, polyetheramide, or butadiene rubber on the concave ultrasonic transmitting / receiving surface, and the central portion is convex. There has been disclosed a method for providing a high-sensitivity ultrasonic probe that is excellent in adhesion to a subject and has low high-frequency propagation loss by providing an ultrasonic wave propagation body. (For example, see Patent Documents 4, 5, and 6)
A method of fixing a biconvex ultrasonic wave propagation body (acoustic medium) on a concave acoustic lens using polymethylpentene is also disclosed. (For example, see Patent Documents 4, 5, and 7)

JP 2008-188415 A International Publication No. 2007/145073 Pamphlet International Publication No. 2008/010509 Pamphlet Japanese Patent No. 2739134 Japanese Patent No. 3268907 Japanese Patent No. 3251328 JP-A-6-254100

  In order to receive high-order harmonics of ultrasonic waves with high sensitivity using an array-type ultrasonic probe, it is necessary to further reduce the attenuation rate of high-order harmonics above the receiving piezoelectric element. .

  However, the methods disclosed in Patent Documents 4, 5, and 6 can be applied to frequencies of about 7.5 MHz. For example, when receiving 15 MHz as a third harmonic, Patent Documents 4 and 5 When an ultrasonic wave propagating body is provided as disclosed, attenuation at the ultrasonic wave propagating body becomes large and cannot be ignored. Moreover, when silicon rubber is used for the ultrasonic wave propagation body as disclosed in Patent Document 7, the amount of attenuation at 15 MHz is further increased.

  The present invention has been made in view of the above problems, and includes an ultrasonic probe that can receive high-order harmonics with high sensitivity, and an ultrasonic probe that can receive high-order harmonics with high sensitivity. An object of the present invention is to provide an ultrasonic diagnostic apparatus.

  In order to solve the above problems, the present invention has the following characteristics.

1. Transmitting element layer for transmitting at least one ultrasonic wave each having electrodes formed on both surfaces facing in the thickness direction, and receiving for receiving at least one ultrasonic wave having electrodes formed on both surfaces facing each other in the thickness direction An ultrasonic probe in which an element layer and a matching layer for matching acoustic impedance of at least one layer are stacked in this order toward a direction in which the ultrasonic wave is transmitted,
The ultrasonic probe according to claim 1, wherein a surface of the transmitting element layer that transmits the ultrasonic waves has a concave shape, and at least an uppermost layer of the matching layer is made of polymethylpentene.

2. The receiving element layer is
2. The ultrasonic probe according to 1, wherein the ultrasonic probe is made of an organic resin and is curved and laminated along a convex surface or a concave surface on the side facing the receiving element layer.

3. The receiving element layer is
3. The ultrasonic probe according to 1 or 2 above, wherein the film is formed to a film thickness of 8 μm to 55 μm using a vinylidene fluoride polymer or a vinylidene fluoride (VDF) copolymer as a material. .

  4). 4. The ultrasonic probe according to any one of 1 to 3, wherein the matching layer has a convex surface on the forefront.

  5. An ultrasonic diagnostic apparatus comprising the ultrasonic probe according to any one of 1 to 4 above.

  According to the present invention, the ultrasonic wave transmitting surface of the transmitting element layer has a concave cross section in the elevation direction, the uppermost matching layer is close to the acoustic impedance of the living body, and the attenuation of high frequency is small. By forming from polymethylpentene, an ultrasonic wave propagating body is unnecessary. Therefore, an ultrasonic probe that can receive high-order harmonics with high sensitivity without attenuation of high-order harmonics by an ultrasonic propagator and an ultrasonic probe that can receive high-order harmonics with high sensitivity are provided. An ultrasonic diagnostic apparatus can be provided.

1 is a diagram illustrating an external configuration of an ultrasonic diagnostic apparatus 100 according to an embodiment. 1 is a block diagram showing an electrical configuration of an ultrasonic diagnostic apparatus 100 in an embodiment. It is sectional drawing which shows the structure of the head part of the ultrasonic probe of 1st Embodiment. It is sectional drawing which shows the structure of the head part of the ultrasonic probe of 2nd Embodiment. It is sectional drawing which shows the example which comprised the matching layer 6 of the ultrasonic probe of 2nd Embodiment by two layers.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. However, the present invention is not limited to the embodiment. In addition, the structure which attached | subjected the same code | symbol in each figure shows that it is the same structure, The description is abbreviate | omitted.

(Each component and operation of ultrasonic diagnostic equipment and ultrasonic probe)
FIG. 1 is a diagram illustrating an external configuration of an ultrasonic diagnostic apparatus according to an embodiment. FIG. 2 is a block diagram illustrating an electrical configuration of the ultrasonic diagnostic apparatus according to the embodiment.

  The ultrasonic diagnostic apparatus 100 transmits an ultrasonic wave (ultrasonic signal) to a subject such as a living body (not shown), and receives the ultrasonic wave reflected from the received subject (echo, ultrasonic signal). The internal state in the sample is imaged as an ultrasonic image and displayed on the display unit 45.

  The ultrasonic probe 1 transmits an ultrasonic wave (ultrasonic signal) to the subject and receives a reflected wave of the ultrasonic wave reflected by the subject. As shown in FIG. 2, the ultrasonic probe 1 is connected to the ultrasonic diagnostic apparatus main body 31 via a cable 33, and is electrically connected to the transmission circuit 42 and the reception circuit 43.

  The transmission circuit 42 transmits an electrical signal to the ultrasonic probe 1 via the cable 33 according to a command from the control unit 46, and transmits ultrasonic waves from the ultrasonic probe 1 to the subject.

  The receiving circuit 43 receives an electrical signal corresponding to the reflected wave of the ultrasonic wave from the subject via the cable 33 from the ultrasonic probe 1 in accordance with a command from the control unit 46.

  The image processing unit 44 images the internal state in the subject as an ultrasonic image based on the electrical signal received by the receiving circuit 43 according to a command from the control unit 46.

  The display unit 45 is composed of a liquid crystal panel or the like, and displays an ultrasonic image imaged by the image processing unit 44 according to a command from the control unit 46.

  The operation input unit 41 includes a switch, a keyboard, and the like, and is provided for the user to input data such as a command for instructing the start of diagnosis and personal information of the subject.

  The control unit 46 includes a CPU, a memory, and the like, and controls each unit of the ultrasonic diagnostic apparatus 100 according to a programmed procedure based on an input from the operation input unit 41.

  FIG. 3 is a cross-sectional view showing the configuration of the head portion of the ultrasonic probe of the first embodiment, and FIG. 4 is a cross-sectional view showing the configuration of the head portion of the ultrasonic probe of the second embodiment. is there.

  In the following description, description will be made based on the coordinate axes indicated by X, Y, and Z in the drawing. The X direction is the elevation direction (the dicing direction), and the Z-axis positive direction is the direction in which ultrasonic waves are transmitted. The Z-axis direction is the stacking direction. Hereinafter, each part will be described in the order of lamination.

  The ultrasonic probe 1 shown in FIGS. 3 and 4 includes a fourth electrode 15, a transmitting element layer 2, a third electrode 14, an intermediate layer 13, a second electrode 10, a receiving element layer 3 on a backing material 5. The first electrode 9 and the matching layer 6 are laminated in this order.

  The transmitting element layer 2 is a piezoelectric element made of an inorganic piezoelectric material such as lead zirconate titanate, and includes a third electrode 14 and a fourth electrode 15 on both surfaces facing each other in the thickness direction.

  In this embodiment, as shown in FIGS. 3 and 4, the surface of the transmitting element layer 2 facing the intermediate layer 13 is a concave surface, and the acoustic convergence that converges the ultrasonic waves transmitted from the transmitting element layer 2 to a predetermined distance. It has a function.

  The third electrode 14 and the fourth electrode 15 are connected to the cable 33 by a connector (not shown), and are connected to the transmission circuit 42 via the cable 33. When an electric signal is input to the third electrode 14 and the fourth electrode 15, the piezoelectric element vibrates and transmits ultrasonic waves from the transmitting element layer 2 in the positive Z-axis direction.

  The thickness of the 3rd electrode 14 and the 4th electrode 15 is about 1-2 micrometers. The thicknesses of the third electrode 14 and the fourth electrode 15 are preferably as thin as possible in terms of acoustic characteristics. However, if the thickness is too thin, cracking or the like occurs in the electrode and the reliability is impaired, so the range of 0.1 to 10 μm, preferably It is desirable to be 0.1-5 μm. In particular, it is desirable that the third electrode 14 on the ultrasonic wave transmitting side be as thin as possible in terms of acoustic characteristics.

  The third electrode 14 and the fourth electrode 15 are formed by vapor deposition or photolithography on both surfaces of the transmission element layer 2 using a metal material such as gold, silver, or aluminum.

  The intermediate layer 13 absorbs the vibration of the receiving element layer 3 so that the transmitting element layer 2 does not resonate and vibrate when the receiving element layer 3 receives and vibrates the reflected ultrasonic wave reflected by the subject. It is provided for.

  In the first embodiment, as shown in FIG. 3, the intermediate layer 13 is curved in the same manner as the transmission element layer 2, and the surface facing the reception element layer 3 is also concave.

  In the second embodiment, as shown in FIG. 4, the surface of the intermediate layer 13 facing the transmitting element layer 2 is curved in the same manner as the transmitting element layer 2, and the surface facing the receiving element layer 3 is It is flat.

  Such an intermediate layer 13 can be formed by molding a resin material. Examples of the resin material used for the intermediate layer 13 include polyvinyl butyral, polyolefin, polyacrylate, polyimide, polyamide, polyester, polysulfone, epoxy, oxetane, and the like.

  The thickness of the intermediate layer 13 is selected depending on the required sensitivity and frequency characteristics, and is about 180 to 190 μm, for example.

  The intermediate layer 13 can be omitted depending on the sensitivity and frequency characteristics to be obtained.

  The receiving element layer 3 is composed of a plurality of piezoelectric elements made of an organic piezoelectric material.

  As the organic piezoelectric material used for the receiving element layer 3, for example, a vinylidene fluoride polymer can be used. Further, for example, a vinylidene fluoride (VDF) copolymer can be used as the organic piezoelectric material. This vinylidene fluoride copolymer is a copolymer (copolymer) of vinylidene fluoride and other monomers. Examples of other monomers include ethylene trifluoride (TrFE) and tetrafluoroethylene (TeFE). Perfluoroalkyl vinyl ether (PFA), perfluoroalkoxyethylene (PAE), perfluorohexaethylene, and the like can be used.

  In general, a piezoelectric element made of an inorganic piezoelectric material can receive only an ultrasonic wave having a frequency band of about twice the frequency of the fundamental wave, but a piezoelectric element made of an organic piezoelectric material is, for example, 4 to 5 times the frequency of the fundamental wave. Ultrasonic waves in a certain frequency band can be received, which is suitable for widening the reception frequency band. Since the ultrasonic signal is received by the organic piezoelectric element 21 having a characteristic capable of receiving such ultrasonic waves over a wide frequency range, the ultrasonic probe 1 and the ultrasonic diagnostic apparatus 100 in the present embodiment are compared. The frequency band can be widened with a simple structure.

  The thickness t of the receiving element layer 3 is appropriately set depending on the frequency of ultrasonic waves to be received, the type of organic piezoelectric material, and the like. When the wavelength of the ultrasonic wave to be received is λ, the receiving efficiency of the receiving element layer 3 is best when the thickness t of the receiving element layer 3 is t = λ / 4.

  The wavelength λ of the ultrasonic wave is obtained by the equation (1) where f is the frequency of the ultrasonic wave and v is the speed of sound in the receiving element layer 3.

λ = v / f (1)
For example, when transmitting an ultrasonic wave having a fundamental frequency of 5 MHz to a subject and receiving a frequency of 10 MHz, which is a second harmonic, if the polyvinylidene fluoride (PVDF) is used as the material of the receiving element layer 3, the sound velocity v is It is 2200 m / s, and if it is substituted into the equation (1), λ = 2200/10 = 220 μm.

  Therefore, when receiving an ultrasonic wave of f = 10 MHz, the thickness t of the receiving element layer 3 having the highest receiving efficiency is 55 μm.

  In order to efficiently receive the second and higher harmonics, the thickness t of the receiving element layer 3 may be set to 55 μm or less. For example, when receiving f = 15 MHz which is the third harmonic, the thickness t of the receiving element layer 3 having the highest receiving efficiency is 37 μm.

  Even when a higher frequency is received, the thickness t of the receiving element layer 3 may be set according to the frequency of the ultrasonic wave to be received. However, if the thickness is too thin, manufacturing becomes difficult and strength is insufficient. It is preferable to be 8 μm or more and 55 μm or less.

  Such a receiving element layer 3 is cast from a solution of an organic piezoelectric material to form a film having a predetermined thickness, heated for crystallization, and then molded into a sheet having a predetermined size. Make it.

  A first electrode 9 and a second electrode 10 are formed on both surfaces of the receiving element layer 3 facing each other in the thickness direction (Z-axis direction).

  The thickness of the 1st electrode 9 and the 2nd electrode 10 is about 1-2 micrometers. The electrode of the receiving element layer 3 should be as thin as possible in terms of acoustic characteristics. However, if the electrode is too thin, cracks and the like are generated in the electrode, and the reliability is impaired, so the range is 0.1 to 10 μm, preferably 0.1 to 5 μm. It is desirable to do. Since the receiving element layer 3 receives high-frequency harmonics, it is desirable that both the first electrode 9 and the second electrode 10 be as thin as possible in terms of acoustic characteristics.

  The first electrode 9 and the second electrode 10 are formed by vapor deposition or photolithography using a metal material such as gold, silver, or aluminum. The electrode used for the receiving element layer 3, particularly the first electrode 9, needs to be formed very thin in order to receive harmonics with high sensitivity. Therefore, it is desirable to use gold having good conductivity as the metal material.

  Since the receiving element layer 3 is made of an organic piezoelectric material, even after the first electrode 9 and the second electrode 10 are formed, the receiving element layer 3 can be easily bent according to the concave shape on the side of the intermediate layer 13 facing the receiving element layer 3. Can do. Therefore, as shown in FIG. 3, the receiving element layer 3 on which the first electrode 9 and the second electrode 10 are formed is bonded along the concave shape of the intermediate layer 13, and the convex surface of the intermediate layer 13 and the receiving element layer 3 are joined together. The vibration of the receiving element layer 3 can be sufficiently absorbed by setting the interval to a predetermined interval.

  In the second embodiment, the receiving element layer 3 on which the first electrode 9 and the second electrode 10 are formed is joined along the plane of the intermediate layer 13 as shown in FIG.

  The first electrode 9 and the second electrode 10 are connected to the receiving circuit 43 via the cable 33.

  When the receiving element layer 3 receives and vibrates the reflected wave of the ultrasonic wave reflected by the subject, an electric signal is generated between the first electrode 9 and the second electrode 10 in the piezoelectric element in accordance with the reflected wave. The electrical signal generated between the first electrode 9 and the second electrode 10 is received by the receiving circuit 43 via the cable 33 and imaged by the image processing unit 44.

  The matching layer 6 has an acoustic impedance that is intermediate between the acoustic impedances of the human body that is the subject and the receiving element layer 3, and matches the acoustic impedance. In the present embodiment, at least the uppermost layer material is polymethylpentene, which is a kind of polyolefin resin. Various resin materials can be used for layers other than the uppermost layer of the matching layer 6.

  The matching layer 6 is formed by molding, for example. In the first embodiment, the receiving element layer 3 side surface of the matching layer 6 is formed in a convex shape as shown in FIG. 3, and in the second embodiment, the receiving element layer of the matching layer 6 is shown in FIG. The surface on the 3 side is formed as a flat surface. In any case, the receiving element layer 3 in which the first electrode 9 and the second electrode 10 are formed is sandwiched between the matching layer 6 and the intermediate layer 13 at a predetermined interval.

  The surface of the matching layer 6 on the side in contact with the subject such as a living body is a flat surface in the first embodiment as shown in FIG. 3 and a convex surface in the second embodiment as shown in FIG. I have to. When the surface is convex as in the second embodiment, the surface of the matching layer 6 and the subject can be more easily adhered to each other. In addition, since the matching layer 6 does not bear the convergence function of the ultrasonic wave, it can be formed in an arbitrary shape.

The acoustic impedance of polymethylpentene is about 1.8 Pa · s · m ^−1, which is close to the acoustic impedance of the human body, 1.5 Pa · s · m ⁻¹ , and the sound velocity is about 2.2 km / s, which is close to the human body. is there. This makes it possible to achieve excellent adhesion to a subject such as a living body without providing a conventionally used ultrasonic wave propagation body.

  In addition, the ultrasonic attenuation rate of polymethylpentene is low compared to other materials such as silicon, and the propagation loss of high-order harmonics is small. For example, when the matching layer 6 is made of a single-layer polymethylpentene having a thickness of 140 μm, the attenuation at a frequency of 15 MHz is about 1.0 dB.

  Furthermore, since polymethylpentene is difficult to transmit gas or liquid, when the uppermost layer of the matching layer 6 is made of polymethylpentene, disinfecting gas or liquid is introduced from the surface of the ultrasonic probe 1 in contact with the subject. It can be prevented that the characteristics of the receiving element layer 3 and the transmitting element layer 2 deteriorate due to intrusion.

  FIG. 5 shows an example in which the matching layer 6 of the ultrasonic probe of the second embodiment is composed of two layers. A matching layer 6b formed of a material having an acoustic impedance intermediate between the matching layer 6a and the receiving element layer 3 is sandwiched between the uppermost matching layer 6a formed of polymethylpentene and the receiving element layer 3. Thus, the acoustic impedance between the receiving element layer 3 and the matching layer 6a is gradually changed. By doing so, matching between the receiving element layer 3 and the matching layer 6a can be achieved, and the receiving sensitivity can be improved.

For example, if the receiving element layer 3 is formed of the acoustic impedance 4.1Pa · s · ^{m -1} degree polyvinylidene fluoride (PVDF), a matching layer 6a made of polymethylpentene about 1.8Pa · s · ^{m -1} As a material for forming the matching layer 6b sandwiched between them, an epoxy resin, a polyphenylene oxide resin, a polystyrene resin, a polyvinyl butyral resin, or the like can be used.

  Further, the matching layer 6b is further formed from a plurality of layers, and the resin material forming each layer is changed, or the content of the filler contained in the resin material of each layer is changed to change the space between the receiving element layer 3 and the matching layer 6a. The acoustic impedance may be changed more gradually. For example, tungsten, ferrite, alumina, or the like can be used as the filler.

  In FIG. 5, the example in which the matching layer 6 of the second embodiment is configured by two layers has been described. However, the matching layer 6 of the ultrasonic probe of the first embodiment can be similarly multilayered.

  Thus, in this embodiment, since the ultrasonic wave propagation body and the acoustic lens are not provided on the upper layer of the reception element layer 3, the reception element layer 3 does not attenuate high-order harmonics with the ultrasonic wave propagation body or the acoustic lens. Can be received.

  As described above, according to the present invention, an ultrasonic probe that can receive high-order harmonics with high sensitivity, and an ultrasonic wave that includes an ultrasonic probe that can receive high-order harmonics with high sensitivity. A diagnostic device can be provided.

DESCRIPTION OF SYMBOLS 1 Ultrasonic probe 2 Transmitting element 3 Receiving element 5 Backing material 6 Matching layer 9 1st electrode 10 2nd electrode 13 Intermediate layer 14 3rd electrode 15 4th electrode 20 Board | substrate material 31 Ultrasonic diagnostic apparatus main body 33 Cable 41 Operation Input unit 42 Transmission circuit 43 Reception circuit 44 Image processing unit 45 Display unit 46 Control unit 100 Ultrasonic diagnostic apparatus

Claims (5)

Transmitting element layer for transmitting at least one ultrasonic wave each having electrodes formed on both surfaces facing in the thickness direction, and receiving for receiving at least one ultrasonic wave having electrodes formed on both surfaces facing each other in the thickness direction An ultrasonic probe in which an element layer and a matching layer for matching acoustic impedance of at least one layer are stacked in this order toward a direction in which the ultrasonic wave is transmitted,
The ultrasonic probe according to claim 1, wherein a surface of the transmitting element layer that transmits the ultrasonic waves has a concave shape, and at least an uppermost layer of the matching layer is made of polymethylpentene. The receiving element layer is
The ultrasonic probe according to claim 1, wherein the ultrasonic probe is made of an organic resin and is curved and laminated along a convex surface or a concave surface on a side facing the receiving element layer. The receiving element layer is
3. The ultrasonic probe according to claim 1, wherein the film is formed to a film thickness of 8 μm to 55 μm using a vinylidene fluoride polymer or a vinylidene fluoride (VDF) copolymer as a material. Child.   The ultrasonic probe according to any one of claims 1 to 3, wherein the matching layer has a convex surface on the forefront.   An ultrasonic diagnostic apparatus comprising the ultrasonic probe according to claim 1.

Images