Ultrasound probes and ultrasound diagnostic equipment

Abstract

The object of the present invention is to provide an ultrasound probe and ultrasound diagnostic apparatus that can protect the patient from electrically active transducer elements, by providing an acoustic lens and / or acoustic window that suppresses discoloration and deterioration of physical properties due to ultraviolet light. [Solution] An ultrasonic probe comprising a laminate composed of at least a back load material, a piezoelectric transducer, and an acoustic matching layer, and an acoustic lens and / or acoustic window for contacting the body surface of a subject and efficiently transmitting ultrasonic waves, wherein the acoustic lens and / or acoustic window is made of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin.

Description

Technical Field

[0001] The present invention relates to an ultrasonic probe and an ultrasonic diagnostic apparatus. More specifically, the present invention relates to an ultrasonic probe or the like that includes an acoustic lens and / or an acoustic window in which discoloration and deterioration of physical properties due to ultraviolet rays are suppressed, and can protect a patient from an electrically active transducer element.

Background Art

[0002] In ultrasonic diagnosis using an ultrasonic probe, sterilization is required after use. And, an acoustic lens and / or an acoustic window that constitutes a part of the housing of the ultrasonic probe and is abutted against the body surface of a subject particularly requires sterilization.

[0003] When the above acoustic lens and / or acoustic window are subjected to immersion disinfection, it may cause a failure. Therefore, wiping disinfection with a low-level disinfectant is generally performed. However, the wiping technique is manual, and there are individual differences in the technique, and sufficient disinfection may not be performed in some cases.

[0004] On the other hand, in recent years, as a sterilization method for an ultrasonic probe that replaces cleaning and wiping with a disinfectant, a method of irradiating ultraviolet rays on the above ultrasonic probe has attracted attention.

[0005] Here, as a material constituting the acoustic lens and / or the acoustic window, a material containing a polyolefin such as polymethylpentene, which is close to the acoustic impedance of a living body and has a small ultrasonic attenuation coefficient, is used from the role of the acoustic lens and / or the acoustic window. Hereinafter, the "material constituting the acoustic lens and / or the acoustic window" is also simply referred to as "acoustic material", and the "material containing a polyolefin" is also simply referred to as "polyolefin material".

[0006] As a technique related to an acoustic lens made of the above polyolefin material, for example, the technique disclosed in Patent Document 1 can be cited. And, in this technique, hydrophilicity and durability are improved by forming a specific organic layer on the acoustic lens made of a polyolefin material.

[0007] However, this polyolefin material had the problem of low UV resistance, leaving room for improvement in the technology related to acoustic lenses made of polyolefin material. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2021-142109 [Overview of the project] [Problems that the invention aims to solve]

[0009] Deep ultraviolet (UV) light, with its short wavelength, has a higher germicidal effect compared to UV light of other wavelengths and is useful for sterilizing ultrasonic probes, as it can inactivate bacteria, viruses, and proto-oocysts. Furthermore, irradiation with deep UV light requires a short sterilization time, making it a simple and reliable method of sterilization.

[0010] Therefore, when considering irradiating ultrasonic probes with ultraviolet light for sterilization, it is considered useful to irradiate them with the deep ultraviolet light described above.

[0011] However, polyolefin materials that constitute acoustic lenses and / or acoustic windows, which are affected by deep ultraviolet irradiation, have poor weather resistance, i.e., resistance to ultraviolet light. When exposed to deep ultraviolet light for a long period of time, they deteriorate and discolor, such as fading. In addition, they may develop cracks or other physical properties and break, which means they can no longer perform their role of protecting patients from electrically active transducer elements. Here, "transducer" refers to a device that is responsible for transmitting ultrasound waves and receiving ultrasound echoes and converting them into electrical signals in ultrasound measurements.

[0012] Therefore, as a method for sterilizing ultrasonic probes, it is necessary to enjoy the benefits of the sterilizing effect of irradiation with deep ultraviolet light while preventing discoloration and deterioration of the physical properties of the acoustic lens and / or acoustic window that constitute the ultrasonic probe.

[0013] This invention has been made in view of the above-mentioned problems and circumstances. The problem to be solved is to provide an ultrasound probe and ultrasound diagnostic device that can protect the patient from electrically active transducer elements, by providing an acoustic lens and / or acoustic window that suppresses discoloration and deterioration of physical properties due to ultraviolet light. [Means for solving the problem]

[0014] The inventors of the present invention investigated the causes of the above problems in order to solve them. As a result, they found that the above problems could be solved by incorporating an ultraviolet absorber that absorbs ultraviolet light in the wavelength range of at least 100 to 280 nm and a polyolefin into the material constituting the acoustic lens and / or acoustic window, and thus arrived at the present invention. In other words, the above-mentioned problems according to the present invention are solved by the following means.

[0015] 1. A laminate comprising at least a back load material, a piezoelectric vibrator, and an acoustic matching layer, It comprises an acoustic lens and / or acoustic window that contact the surface of the subject's body to efficiently transmit ultrasound, The acoustic lens and / or acoustic window is made of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin. An ultrasonic probe characterized by the following features.

[0016] 2. The polyolefin contains at least polymethylpentene. The ultrasonic probe according to paragraph 1, characterized in that

[0017] 3. The maximum absorption wavelength of the ultraviolet absorber is within the range of 254 to 325 nm. The ultrasonic probe according to claim 1, characterized in that...

[0018] 4. The ultrasonic probe according to claim 1, characterized in that the ultraviolet absorber contains at least one, or two or more compounds selected from 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl]-5-(octyloxy)-phenol, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol, [2-hydroxy-4-(octyloxy)phenyl](phenyl)methanone, and 2-[4,6-bis(1,1′-biphenyl-4-yl)-1,3,5-triazin-2-yl]-5-[2-(2-ethylhexyl)oxy)]phenol.

[0019] 5. An organic layer is formed on the surface of the acoustic lens or the surface of the acoustic window, and the organic layer has high ultraviolet resistance The ultrasonic probe according to claim 1, characterized in that...

[0020] 6. The ultrasonic probe according to claim 5, characterized in that the organic layer contains at least one compound selected from acrylate, urethane, urethane acrylate, silicone, and para-xylene-based polymer. The ultrasonic probe according to claim 5, characterized in that...

[0021] 7. The ultrasonic probe according to claim 5, characterized in that the organic layer contains an ultraviolet absorber and a light stabilizer. The ultrasonic probe according to claim 5, characterized in that...

[0022] 8. The ultrasonic probe according to claim 1, characterized in that the acoustic lens or the acoustic window contains carbon black or carbon black nanotubes. The ultrasonic probe according to claim 1, characterized in that...

[0023] 9. The acoustic lens or the acoustic window is colored black, The organic layer is colored with a different color from the acoustic lens or the acoustic window. An ultrasonic probe as described in any one of paragraphs 1 to 8, characterized by the above.

[0024] 10. The acoustic lens or the acoustic window contains an ultraviolet scattering agent. The ultrasonic probe according to paragraph 1, characterized in that

[0025] 11. The ultraviolet scattering agent contains titanium dioxide, The acoustic lens or the acoustic window is colored white. The organic layer is colored with a different color from the acoustic lens or the acoustic window. The ultrasonic probe according to paragraph 10, characterized in that

[0026] 12. Equipped with the acoustic wave probe described in paragraph 1. An ultrasound diagnostic device characterized by the following features. [Effects of the Invention]

[0027] The present invention provides an ultrasound probe and ultrasound diagnostic apparatus that include an acoustic lens and / or acoustic window in which discoloration and deterioration of physical properties due to ultraviolet light are suppressed, and which can protect the patient from electrically active transducer elements. Although the mechanism by which the effects of this invention manifest or the mechanism of action are not yet clear, we speculate as follows.

[0028] The ultrasonic probe of the present invention is equipped with an acoustic lens and / or acoustic window that come into contact with the body surface of the subject, and therefore requires sterilization, for which deep ultraviolet light is useful. Polyolefin material is used as the material constituting the acoustic lens and / or acoustic window to efficiently transmit ultrasound, but this polyolefin material has poor resistance to deep ultraviolet light.

[0029] Deep ultraviolet (UV) radiation is performed, for example, by germicidal lamps, the majority of which emits light with a wavelength of 254 nm. Hereafter, "deep ultraviolet" will also be simply referred to as "UV-C". This 254 nm deep ultraviolet radiation has an extremely strong germicidal effect and is therefore also called germicidal rays.

[0030] In contrast, the ultrasonic probe of the present invention contains an ultraviolet absorber in addition to a polyolefin material in the material constituting the acoustic lens and / or acoustic window, which are part of its housing, thereby suppressing the degradation of the polyolefin material. Furthermore, since the ultraviolet absorber is limited to one that absorbs ultraviolet light in the range of 100 to 280 nm, the absorption rate of deep ultraviolet light is higher than that of materials containing general ultraviolet absorbers.

[0031] Therefore, when sterilizing an ultrasonic probe, deterioration of the acoustic lens and / or acoustic window due to deep ultraviolet light can be efficiently prevented. [Brief explanation of the drawing]

[0032] [Figure 1] An example of a schematic configuration diagram of an ultrasound diagnostic device equipped with an ultrasound probe. [Figure 2] An example of a schematic diagram of an ultrasonic sensor equipped with an acoustic lens. [Figure 3] An example of a schematic diagram of an ultrasonic probe equipped with an acoustic window. [Figure 4] Enlarged cross-sectional view of a piezoelectric element unit [Figure 5] Spectral energy distribution graph of a germicidal lamp [Figure 6] Absorption spectrum graph of UV absorber [3] [Figure 7] Absorption spectrum graph of UV absorber [4] [Figure 8] Schematic diagram of an example of an acoustic lens with an organic layer formed on it. [Figure 9] Frequency response graph of the ultrasonic sensor in an ultrasonic probe [Figure 10] Visual images of each acoustic window of an ultrasound probe after deep ultraviolet irradiation. [Modes for carrying out the invention]

[0033] The ultrasonic probe of the present invention comprises a laminate composed of at least a back load material, a piezoelectric transducer, and an acoustic matching layer, and an acoustic lens and / or acoustic window for efficiently transmitting ultrasonic waves when in contact with the body surface of a subject, wherein the acoustic lens and / or acoustic window is composed of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin. This feature is a technical feature common to or corresponding to each of the embodiments (appearances) described below.

[0034] The present invention, its components, and embodiments and models for carrying out the present invention will be described in detail below. In this application, "~" is used to mean that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0035] While the advantages and features provided by one or more embodiments of the present invention will be better understood from the following detailed description and accompanying drawings, these drawings are for illustrative purposes only and are not intended to define any limitations of the present invention.

[0036] 1. Ultrasound diagnostic equipment Multiple electrical signals transmitted from the transmitter unit of the ultrasound diagnostic device are applied to multiple piezoelectric transducers arranged in an array via cables and flexible printed circuits (FPCs). The piezoelectric transducers excite (transmit) ultrasonic waves (mechanical vibrations) in response to the applied electrical signals.

[0037] The excited ultrasound waves are acoustically matched with the living body by the first acoustic matching layer, the second acoustic matching layer, and an acoustic lens, and are focused by the acoustic lens before being transmitted into the living body. In addition, the piezoelectric transducer generates (receives) an electrical signal in response to the ultrasound waves returning from the living body due to the piezoelectric effect.

[0038] After being converted into an electrical signal, it is transmitted via cable to the receiving unit of the ultrasound diagnostic device. The receiving unit processes the received signal and displays the image of the received signal on the display unit of the ultrasound diagnostic device, allowing the patient's internal images to be viewed on the monitor.

[0039] Figure 1 shows an example of a schematic configuration diagram of an ultrasound diagnostic device equipped with an ultrasound probe.

[0040] The ultrasound probe 1 is connected to the main unit 2 by cable 1a and probe connector 1b. The ultrasound diagnostic device 100 includes a monitor 3 that displays the images diagnosed by the ultrasound probe 1.

[0041] Figure 2 shows an example of a schematic configuration diagram of an ultrasonic sensor equipped with an acoustic lens.

[0042] The ultrasonic sensor 10 comprises an acoustic lens 11 and a laminate 12, the laminate 12 being composed of an acoustic matching layer 121, a piezoelectric vibrator 122, a back load material 123, and a segmented groove 124. The acoustic matching layer 121 is composed of a first matching layer 121a and a second matching layer 121b.

[0043] (1.1) Acoustic Lens The acoustic lens 11 is a lens that focuses ultrasound waves and plays a role in efficiently transmitting ultrasound waves by contacting the surface of the subject's body. The acoustic lens 11 has an acoustic impedance that is approximately intermediate between that of the acoustic matching layer 121 and that of the living body.

[0044] For example, the acoustic lens 11 is bonded to the acoustic matching layer 121 via any adhesive. The acoustic lens 11 also has a shape that can focus ultrasonic waves. For example, the surface of the acoustic lens 11 has a convex surface that is raised in the center.

[0045] Furthermore, the acoustic lens 11 is not limited to a convex surface; it may also be flat or concave, and may consist of two or more layers, as long as it can focus ultrasonic waves. Its surface may also be uneven or flat.

[0046] The acoustic lens 11 according to the present invention is made of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin, and uses refraction to focus the ultrasonic beam and improve resolution. Hereinafter, in this specification, "deep ultraviolet light" is defined as ultraviolet light in the above range of 100 to 280 nm wavelength.

[0047] (1.2) Laminate The laminate 12 according to the present invention is composed of a back load material 123, a piezoelectric vibrator 122, and an acoustic matching layer 121.

[0048] (back load material) The rear load material 123 is attached to the base side of the flexible printed circuit board (FPC) via adhesive, mechanically supporting the piezoelectric vibrator 122 and acoustically damping the piezoelectric vibrator 122, thereby shortening the ultrasonic pulse waveform.

[0049] The back load material 123 is provided on the side of the piezoelectric transducer 122 opposite to the biological side, and supports the piezoelectric transducer 122 while absorbing the ultrasonic waves transmitted to the side of the piezoelectric transducer 122 opposite to the biological side. As the material of the back load material 123, for example, natural rubber, epoxy resin, and thermoplastic resin can be used.

[0050] (Piezoelectric vibrator) The piezoelectric transducer 122 is an element for transmitting and receiving ultrasonic waves. A ground electrode layer is pre-formed on the upper surface of the piezoelectric transducer 122 as a first electrode layer, and a positive electrode layer is pre-formed on the lower surface as a second electrode layer.

[0051] The piezoelectric transducer 122 generates ultrasound based on a drive signal supplied from the ultrasound diagnostic device 100. The piezoelectric transducer 122 also receives ultrasound waves reflected from within the subject and converts them into a received signal.

[0052] Furthermore, any known arrangement method can be arbitrarily applied to the piezoelectric vibrator 122. For example, the piezoelectric vibrator 122 may be a 1D array probe in which multiple vibrators are arranged one-dimensionally (in a row), or it may be a 2D array probe in which multiple vibrators are arranged two-dimensionally.

[0053] Multiple electrical signals transmitted from the transmitting unit (not shown) of the main unit 2 are applied to multiple piezoelectric vibrators 122 arranged in an array via cable 1a and a flexible printed circuit board (FPC).

[0054] The piezoelectric transducer 122 excites (transmits) ultrasonic waves (mechanical vibrations) in response to an applied electrical signal. The excited ultrasonic waves are acoustically matched with the living body by the acoustic matching layer 121 and the acoustic lens 11, and are focused by the acoustic lens 11 before being transmitted into the living body.

[0055] Furthermore, the piezoelectric transducer 122 generates (receives) an electrical signal in response to ultrasound waves returning from the body due to the piezoelectric effect. This electrical signal is transmitted to the receiving unit of the main unit 2 via cable 1a. The signal received by the receiving unit (not shown) is then processed by the ultrasound diagnostic device 100, and an image of the received signal is displayed on the monitor 3, allowing the patient to confirm an image of the inside of their body.

[0056] For example, materials such as lead zirconate titanate (PZT), piezoelectric ceramics, lead niobate zincate titanate (PZNT), and titanium magnesium niobate titanate (PMNT) can be used to constitute the piezoelectric vibrator 122.

[0057] (acoustic matching layer) The acoustic matching layer 121 is a conductor and is designed to efficiently transmit and receive ultrasound to and from the subject (living body). The acoustic matching layer 121 is laminated on the upper surface (ground electrode layer side) of the piezoelectric transducer 122 via a pressure-cured insulating adhesive layer.

[0058] The acoustic matching layer 121 is a layer for matching the acoustic characteristics of the piezoelectric vibrator 122 and the acoustic lens 11. The acoustic matching layer 121 is made of a material having an acoustic impedance that is approximately intermediate between that of the piezoelectric vibrator 122 and the acoustic lens 11.

[0059] A flexible printed circuit board (FPC) is laminated on the lower surface (positive electrode layer side) of the piezoelectric vibrator 122 via a pressure-cured insulating adhesive layer.

[0060] This flexible printed circuit board (FPC) has a polyimide base portion, and a conductive pattern corresponding to the piezoelectric vibrator 122 is formed on the side of the base portion facing the piezoelectric vibrator 122. In addition, both sides of the flexible printed circuit board (FPC) extend beyond the laminated portion with the piezoelectric vibrator 122, and electrode extraction portions are formed at both ends of the extended portions.

[0061] In Figure 2, the acoustic matching layer 121 is composed of a first matching layer 121a and a second matching layer 121b, but the acoustic matching layer 121 may be a single layer or a multi-layered layer of three or more. If the acoustic matching layer 121 consists of multiple layers, each layer may be bonded together with an adhesive commonly used in the art. For example, an epoxy adhesive may be used as the adhesive.

[0062] From the viewpoint of adjusting acoustic characteristics, it is preferable that the acoustic matching layer 121 consists of multiple layers with different acoustic impedances. More preferably, the impedance of each layer in the multiple layers is set to gradually or continuously approach the acoustic impedance of the acoustic lens 11 toward the acoustic lens 11.

[0063] The acoustic matching layer 121 can be made of various known materials. Examples of materials that can be used to make up the acoustic matching layer 121 include aluminum, aluminum alloys, magnesium alloys, Macol glass, glass, fused silica, and copper graphite, and the like.

[0064] In addition to the materials mentioned above, resins can also be used as materials for the acoustic matching layer 121. Examples of such resins include polyethylene, polypropylene, polycarbonate, ABS resin, AAS resin, AES resin, nylon, polyphenylene oxide, polyphenylene sulfide, polyphenylene ether, polyetheretherketone, polyamideimide, polyethylene terephthalate, epoxy resin, and urethane resin.

[0065] 2. Ultrasound probe The ultrasonic probe 1 is equipped with an ultrasonic sensor 10 and electrical signal lines, which are fixed inside the housing case. The inside of the housing is filled with epoxy resin or foam material (such as urethane) to improve the electrical isolation between the signal lines.

[0066] Since the ultrasound probe 1 may be contaminated with bodily fluids or pathogens after use, it is required to thoroughly clean and then sterilize or disinfect it before reuse.

[0067] While it is common practice to disinfect the acoustic lens 11, which is part of the ultrasonic sensor 10 installed in the ultrasonic probe 1, by wiping it with a low-level disinfectant, this wiping technique is manual, and there are individual differences in technique, which can sometimes result in insufficient disinfection. Therefore, in recent years, ultraviolet irradiation devices have been used as an alternative method for regenerating ultrasound probes.

[0068] (2.1) Configuration The acoustic lens and / or acoustic window provided in the ultrasound probe 1 contact the body surface of the subject to efficiently transmit ultrasound. The acoustic lens and / or acoustic window according to the present invention is made of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin.

[0069] Figure 3 shows an example of a schematic configuration of an ultrasonic probe equipped with an acoustic window.

[0070] In Figure 3, the ultrasonic probe 1 has a grip section 80, an insertion section 90, and a tip storage section 50, to which a cable 1a is connected. The ultrasonic probe 1 also consists of a piezoelectric element unit 20, an acoustic window 30, a oscillating mechanism 40, a reservoir 60, and a signal line 70. In Figure 3, "FL" is the frame, and "aq" is the acoustic medium liquid filled in the internal space.

[0071] As shown in Figure 3, the ultrasound probe 1 comprises an insertion section 90 including a tip storage section 50 that is inserted into a body cavity, and a grip section 80 that is grasped by an operator outside the body cavity, and is configured to be connectable to a cable 1a connected to the main body 2. Multiple signal lines 70 are drawn out from the tip storage section 50 and can be connected to the cable 1a by passing through the insertion section 90 and the grip section 80.

[0072] Furthermore, although the ultrasound probe 1 is configured to be connectable to the ultrasound diagnostic device 100 via cable 1a, it may also be configured to be connectable to the ultrasound diagnostic device 100 wirelessly without a cable.

[0073] (2.2) Tip storage section The tip storage section 50 is constructed by joining an acoustic window 30, which forms part of the housing of the ultrasonic probe 1, with a frame FL, which is a holding member, and includes a piezoelectric element unit 20 and a rocking mechanism 40 for holding and rocking it. It also includes an internal space (the part filled with acoustic medium liquid aq in Figure 3) that is filled with an acoustic medium liquid aq for transmitting ultrasonic signals.

[0074] (acoustic medium liquid) The internal space (the area filled with the acoustic medium liquid aq in Figure 3) is a liquid-tightly sealed space by the acoustic window 30 and frame FL, and contains the acoustic medium liquid aq.

[0075] Figure 4 is an enlarged cross-sectional view of the piezoelectric element unit.

[0076] The ultrasonic waves transmitted from the piezoelectric element 222 constituting the piezoelectric element unit 20 propagate through the acoustic matching layer 221, acoustic lens 21, acoustic medium liquid aq, and acoustic window 30 in that order, reaching the living body. The ultrasonic waves reflected by the tissues within the living body propagate through the respective mediums in the reverse order and are received by the piezoelectric element 222.

[0077] Various known acoustic media liquids (aq) can be used as the acoustic medium liquid (aq).

[0078] Density, sound velocity, and acoustic impedance can be measured, for example, by the following methods.

[0079] The density can be measured using an electronic hydrometer SD-200L (manufactured by Alpha Mirage) in accordance with the density measurement method of Method A (water displacement method) described in JIS-K7112 02.

[0080] The speed of sound can be measured at 25°C using a sing-around type sound velocity measuring device manufactured by Ultrasonic Industries Co., Ltd., in accordance with JIS Z2353-2003.

[0081] Acoustic impedance can be derived from density and sound velocity according to the following formula. Acoustic impedance (Mrayl) = density (×10) 3 kg / m 3 )×Sound velocity(×10 3 m / sec)

[0082] When ultrasound propagates between different media, it is reflected in proportion to the difference in acoustic impedance between the media. When using a material with an acoustic impedance close to that of living tissue for the acoustic window 30, it is preferable that the acoustic medium liquid aq also has an acoustic impedance close to that of living tissue. This suppresses the reflection of ultrasound between the acoustic medium liquid aq and the acoustic window 30, thereby suppressing noise (artifacts) caused by the multiple propagation of ultrasound within the living tissue due to this reflection, and resulting in the acquisition of ultrasound images with improved accuracy.

[0083] (frame) Frame FL is sealed to the inner wall of the acoustic window 30 by sealing members such as O-rings or gaskets and adhesives, thereby creating a liquid-tight seal inside the tip storage section 50.

[0084] The frame FL can be made of, for example, metal or resin. If the frame FL is made of metal, for example, an aluminum frame FL can be used.

[0085] When using a resin frame FL, it is desirable to use a resin that does not swell upon contact with the acoustic medium liquid aq. The frame FL is also provided with wiring holes (not shown) for passing the aforementioned multiple signal lines 70. In order to maintain the airtight state of the tip storage section 50, the signal lines 70 and the frame FL are sealed liquid-tightly with an adhesive or the like at the wiring holes.

[0086] (Piezoelectric element unit) The piezoelectric element unit 20 is composed of an acoustic lens 21 and a laminate 22, the laminate 22 being composed of an acoustic matching layer 221, a piezoelectric element 222, and a back load material 223.

[0087] Since the piezoelectric element unit 20 is positioned similarly to the ultrasonic sensor equipped with the acoustic lens described above in this invention, a description of the acoustic matching layer 221, piezoelectric element 222, and back load material 223 constituting the laminate 22 will be omitted.

[0088] (Acoustic window) The acoustic window 30 is a protective member for protecting the piezoelectric element unit 20 and other components from pressure caused by contact with living tissue, and is provided in a position that covers the side of the tip storage section 50 that comes into contact with living tissue.

[0089] (Oscillating mechanism) The oscillating mechanism 40 includes a transmission mechanism 42 that holds and oscillates the piezoelectric element unit 20, and a motor 41 that drives the rotation of the gear (transmission mechanism) in the transmission mechanism 42.

[0090] The oscillating mechanism 40 oscillates the piezoelectric element unit 20 in conjunction with the rotation of the gear (transmission mechanism) in the transmission mechanism 42, thereby scanning the ultrasonic signal.

[0091] In addition, a rotating mechanism (not shown) that holds and rotates the piezoelectric element unit 20 may be provided along with, or instead of, the oscillating mechanism 40 that holds and oscillates the piezoelectric element unit 20.

[0092] Furthermore, in the transmission mechanism section 42, in addition to gears, other devices such as timing belts and wires can be used as transmission mechanisms to oscillate the piezoelectric element unit 20.

[0093] 3. Effects of ultraviolet radiation During ultrasound diagnostics using an ultrasound diagnostic device, ultraviolet light is irradiated onto the acoustic lens and / or acoustic window as a method of regenerating the ultrasound probe to prevent healthcare-associated infections in patients and healthcare workers. Among the ultraviolet light irradiated, deep ultraviolet light (UV-C) is suitable for ultrasound diagnostics because it has a short processing time, is simple, has a stable sterilization effect, and has a higher germicidal effect compared to other ultraviolet light, inactivating bacteria, viruses, and proto-oocysts. As mentioned above, in this specification, "deep ultraviolet light" is defined as ultraviolet light within the wavelength range of 100 to 280 nm.

[0094] Hereinafter, "irradiating with deep ultraviolet light" will also be simply referred to as "UV-C irradiation," and in this embodiment, it is assumed that the majority of the synchrotron radiation from the UV-C irradiation is deep ultraviolet light with a wavelength of 254 nm. The setting range for the ultraviolet irradiation conditions in the ultraviolet irradiation machine will be described later.

[0095] UV-C irradiation is performed, for example, by germicidal lamps. The majority of the light emitted by germicidal lamps is deep ultraviolet light with a wavelength of 254 nm. This deep ultraviolet light with a wavelength of 254 nm has an extremely strong germicidal effect and is therefore also called germicidal rays.

[0096] Figure 5 is a spectral energy distribution graph of a germicidal lamp.

[0097] Frequent UV-C irradiation of plastic products can cause the polymer bonds between plastics to break, potentially leading to cracks in acoustic lenses and / or acoustic windows, which are plastic products, and destroying their physical properties.

[0098] Thus, when the physical properties are destroyed, degradation occurs, leading to problems such as embrittlement, discoloration, decreased elasticity, reduced mechanical performance, and shortened lifespan, making it impossible to protect the patient from electrically active transducer elements.

[0099] Table I is an example table showing the wavelengths of ultraviolet light that cause polymer degradation. Table I shows that the main ultraviolet wavelengths that cause polymer degradation are in the range of 290–325 nm.

[0100] Although not listed in Table I, the ultraviolet wavelength at which the polyolefin according to the present invention degrades is in the range of 300 to 310 nm.

[0101] [Table 1]

[0102] (Ultraviolet irradiation machine) An example of an ultraviolet irradiation device that emits deep ultraviolet (UV-C) light is the "Antigermix S1" manufactured by Germitec ("Antigermix" is a registered trademark of the company). The following explanation will assume that the "Antigermix S1" manufactured by Germitec ("Antigermix" is a registered trademark of the company) is used as the ultraviolet irradiation device that emits deep ultraviolet (UV-C) light.

[0103] Furthermore, in the embodiments described later, the wavelength of ultraviolet light irradiated by the above-mentioned ultraviolet irradiator, and the ultraviolet irradiation conditions in the above-mentioned ultraviolet irradiator, are set to be within the range of 200 to 280 nm with a peak of 254 nm.

[0104] The ultraviolet irradiation unit has one UV irradiation tower at each of the four corners, and two UV irradiation towers on the floor. Therefore, there are a total of six UV irradiation towers. Germicidal lamps are also installed in these UV irradiation towers.

[0105] Reflectors are provided on the top, bottom, left, and right sides of the inner surface of the ultraviolet irradiation device. Furthermore, the device is designed so that the object to be irradiated, which is placed in the center of the device, is exposed to ultraviolet light from all directions.

[0106] 4. Materials constituting acoustic lenses and / or acoustic windows In the acoustic lenses and / or acoustic windows according to the present invention, the compatibility between the polymer contained in the materials constituting them and other additives is important, and at least polyolefin is used as the polymer.

[0107] Various known polymers are used as materials for general acoustic lenses and / or acoustic windows. However, polymers can degrade when exposed to ultraviolet light, so it is necessary to reduce the effects of such ultraviolet light exposure.

[0108] Therefore, it is necessary to include the following ultraviolet absorber in the material constituting the acoustic lens and / or acoustic window according to the present invention.

[0109] (4.1) UV absorbers (Features) UV absorbers have the following characteristics (1) to (8). (1) It can strongly absorb ultraviolet rays. (2) It has excellent thermal stability, does not change even during processing in high-temperature environments, and has low volatility. (3) It has good chemical stability and does not undergo harmful reactions with other components in the material. (4) It has excellent bonding properties, disperses uniformly in the material, and does not cause phenomena such as blooming or seepage. (5) The UV absorber itself has good photochemical stability, does not decompose, and does not discolor. (6) It is colorless, non-toxic, and odorless. (7) Excellent durability against immersion and washing. (8) It is low-cost and readily available.

[0110] UV absorbers generally exhibit excellent effects even in small amounts. Therefore, adding a UV absorber to a polyolefin material hardly changes the acoustic impedance or ultrasonic attenuation rate of the polyolefin material, thus maintaining the acoustic characteristics of the ultrasonic sensor.

[0111] UV absorbers are substances whose own structure does not change. Furthermore, UV absorbers protect substances to which they are added by converting high-energy ultraviolet light into thermal energy or by emitting longer light waves without destruction, thereby avoiding damage from ultraviolet radiation.

[0112] In ultrasound probes, it is important that the material used in the acoustic lens or acoustic window, which comes into contact with the patient, is non-toxic, like an ultraviolet absorber.

[0113] Adding ultraviolet absorbers to materials constituting acoustic lenses and / or acoustic windows does not affect the biological evaluation and biocompatibility tests specified in ISO 10993-1.

[0114] The ultraviolet absorber according to the present invention is an ultraviolet absorbing compound that absorbs ultraviolet light in the wavelength range of 100 to 280 nm. The above wavelength range is selected based on the ultraviolet irradiation conditions in the ultraviolet irradiation device during sterilization using an ultrasonic probe.

[0115] The acoustic lens and / or acoustic window according to the present invention is made of a material containing an ultraviolet absorber in addition to polyolefin, thereby preventing discoloration, deterioration of strength, and other issues of the acoustic lens and / or acoustic window.

[0116] The ultraviolet absorber according to the present invention plays a role in absorbing deep ultraviolet (UV-C) rays in particular, converting them into thermal energy, and releasing it. Since thermal energy has a lower impact on plastics than ultraviolet rays, the inclusion of the ultraviolet absorber in the materials constituting the acoustic lens and / or acoustic window according to the present invention can contribute to the stabilization of plastic materials.

[0117] Furthermore, if the material can absorb deep ultraviolet light at a wavelength of 254 nm, which accounts for the majority of the radiation emitted by germicidal lamps, and efficiently absorb ultraviolet light at a wavelength of 300-310 nm, which degrades polyolefins, it is thought that this can contribute to stabilizing polyolefin materials.

[0118] UV absorbers can exhibit excellent efficacy even when used in amounts ranging from 0.1% to 1.0% by mass. In other words, UV absorbers exhibit excellent efficacy even in small amounts.

[0119] Therefore, for example, if the material constituting the acoustic lens and / or acoustic window according to the present invention contains polyolefin, and the material contains an ultraviolet absorber, the amount of the ultraviolet absorber can be small, so the acoustic impedance of the polyolefin is not significantly affected. Furthermore, the effect on the ultrasonic attenuation rate does not change much.

[0120] As a result, if a small amount of ultraviolet absorber is included in the polyolefin-containing material constituting the acoustic lens and / or acoustic window, the acoustic properties can be maintained even when exposed to ultraviolet light, thus ensuring stable acoustic performance and ultrasound images of the ultrasound probe.

[0121] Furthermore, it is useful to add carbon black and carbon nanotubes as ultraviolet absorbers to polyolefin-containing materials that constitute acoustic lenses and / or acoustic windows. Carbon nanotubes are particularly preferred because they absorb 99% of light (electromagnetic waves) across a wide wavelength range from deep ultraviolet (UV-C) to visible light and far infrared (F-IR) from 200 nm to 200 μm.

[0122] (kinds) The ultraviolet absorber contained in the material constituting the acoustic lens and / or acoustic window according to the present invention may be any ultraviolet absorber that absorbs ultraviolet light in the wavelength range of 100 to 280 nm.

[0123] Typical compounds contained in UV absorbers include benzophenone-based, benzotriazole-based, anilide-based, cyanoacrylate-based, and triazine-based compounds, each absorbing different wavelengths of ultraviolet light and having different maximum absorption wavelengths.

[0124] Examples of ultraviolet absorbing compounds having a maximum absorption wavelength in the range of 254 to 325 nm include the ultraviolet absorbers listed in (1) to (5) below. These ultraviolet absorbers may be used individually or in combination of two or more. (1) 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol (2) 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2yl]-5-(octyloxy)-phenol (3) 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyloxy)phenol (4)[2-Hydroxy-4-(octyloxy)phenyl](phenyl)methanone (5)2-[4,6-bis(1,1′-biphenyl-4-yl)-1,3,5-triazine-2-yl]-5-[2-(2-ethylhexyl)oxy)]phenol

[0125] Among these, 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol is preferred from the viewpoint of further improving the weather resistance of the molded product.

[0126] The above-mentioned ultraviolet absorbing compounds may be included in the ultraviolet absorber individually or in combination of two or more.

[0127] (Method for measuring the maximum absorption wavelength) The maximum absorption wavelength of an ultraviolet absorber can be measured specifically as follows:

[0128] A solvent capable of dissolving the UV absorber is prepared, and the UV absorber is added to this solvent and dissolved. The absorption spectrum in the wavelength range of 200 to 450 nm is measured using a UV-Vis spectrophotometer. The wavelength at which the absorbance is maximum is defined as the maximum absorption wavelength.

[0129] (Specific example) Examples of commercially available UV absorbers include the following. The product names, manufacturers, maximum absorption wavelengths, and compound systems of these commercially available products are shown in Table II. Furthermore, some of the structural formulas of these UV absorbers are shown below.

[0130] <UV absorber [1]> • Product name: "Adeka Stub LA-46" Compound name: 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol

[0131] <UV absorber [2]> ·Product name “Eusorb UV-164” • Compound name: 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2yl]-5-(octyloxy)-phenol

[0132] <UV absorber [3]> • Product name: "Tinuvin 1577 ED" • Compound name: 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)-phenol

[0133] <UV absorber [4]> • Product name: "Tinuvin 1600" Compound name: 2-[4,6-bis(1,1′-biphenyl-4-yl)-1,3,5-triazine-2-yl]-5-[2-(2-ethylhexyl)oxy)]phenol

[0134] <UV absorber [5]> • Product name: "Adeka Stub 1413" • Compound name: [2-Hydroxy-4-(octyloxy)phenyl](phenyl)methanone

[0135] <UV absorber [6]> • Product name: "Chimassorb 81" (Chimassorb is a registered trademark of BASF) • Compound name: 2-hydroxy-4-(octyloxy)benzophenone

[0136] [Table 2]

[0137] (Absorption rate of deep ultraviolet light) The absorption rate of deep ultraviolet light by ultraviolet absorbers will be specifically explained below using ultraviolet absorbers [3] and [4].

[0138] Figure 6 is an absorption spectrum graph of the ultraviolet absorber [3].

[0139] The UV absorber [3] efficiently absorbs deep ultraviolet light with a wavelength of 254 nm, which accounts for the majority of the synchrotron radiation from the germicidal lamp, with an absorption rate of approximately 0.5. From this, it can be seen that the UV absorber [3] efficiently absorbs ultraviolet light with a wavelength of 254 nm irradiated from the germicidal lamp and efficiently absorbs ultraviolet light in the wavelength range of 290 to 325 nm, which is the wavelength range in which polymers degrade.

[0140] Therefore, it is believed that the polyolefin according to the present invention can efficiently absorb ultraviolet light at a wavelength of 300-310 nm, which degrades the polyolefin, and that discoloration and deterioration of physical properties of acoustic lenses and / or acoustic windows composed of polyolefin materials with low UV weather resistance can be prevented.

[0141] Figure 7 is an absorption spectrum graph of the ultraviolet absorber [4].

[0142] The UV absorber [4] has a certain degree of absorption rate for deep ultraviolet light at a wavelength of 254 nm, which accounts for the majority of the radiation emitted by the germicidal lamp, but this absorption rate is 0.2. From this, it can be seen that the UV absorber [4] absorbs ultraviolet light at a wavelength of 254 nm emitted from the germicidal lamp with a certain degree of efficiency, and absorbs ultraviolet light in the wavelength range of 290 to 325 nm, which is the wavelength range in which polymers degrade, with a certain degree of efficiency.

[0143] Therefore, it is believed that the polyolefin according to the present invention can absorb ultraviolet light at a wavelength of 300-310 nm, which degrades the polyolefin, to a certain extent, and that discoloration and deterioration of physical properties of acoustic lenses and / or acoustic windows made of polyolefin material with low UV weather resistance can be prevented.

[0144] (4.2) Polyolefins Because the acoustic lens according to the present invention is composed of a material containing polyolefin, the acoustic lens can achieve a reduction in the attenuation coefficient and an improvement in water resistance.

[0145] Examples of polyolefins include polystyrene, polyethylene, polypropylene, polymethylpentene, and ethylene-propylene copolymers.

[0146] (Polymethylpentene)

[0147] Among the above, polymethylpentene is preferred as the polyolefin according to the present invention. Polymethylpentene is a synthetic resin belonging to thermoplastic resins, which are a type of polyolefin, and its CAS number is 25068-26-2. Polymethylpentene is also known as TPX and is a registered trademark of Mitsui Chemicals, the exclusive manufacturer.

[0148] The acoustic impedance within a living organism is 1.6 × 10⁻⁶. 6 kg / m2 The acoustic impedance of polymethylpentene is 1.7 × 10⁻⁶ sec. 6 kg / m 2 Since it is sec, the acoustic impedance of polymethylpentene is close to that of living organisms. "Acoustic impedance" is a numerical representation of how easily sound propagates, and can be calculated using the formula: density of the medium × speed of sound in the medium. Ultrasound is reflected when the difference in acoustic impedance is large, and transmitted when it is small.

[0149] Furthermore, polymethylpentene has a relatively low attenuation rate of 0.25 dB / MHz·mm. In addition, it has excellent chemical resistance and electrical insulation properties, and is non-toxic, making it suitable as a material for acoustic lenses and / or acoustic windows in ultrasonic probes. However, polymethylpentene has the disadvantage of being susceptible to degradation by ultraviolet light.

[0150] (4.3) Other additives The materials constituting the acoustic lens and / or acoustic window according to the present invention may contain additives other than the aforementioned ultraviolet absorber, as needed. There are no particular limitations on such additives, but examples include light stabilizers, ultraviolet scattering agents, colorants, etc.

[0151] The effectiveness of an additive generally depends on the dispersibility of the additive itself. When incorporating additives into the above-mentioned materials, the basic principle is to select an additive with good dispersibility that is compatible with the resin contained in the material. However, a dispersant may be used in combination to improve the dispersibility of the additive.

[0152] As described above, by using a dispersant in combination, the dispersibility of the additive can be improved, thereby reducing the amount of additive added to the material. This reduces costs and suppresses the deterioration of physical properties caused by the additive.

[0153] (Light stabilizer) Light stabilizers react with degradation factors (radicals) generated by ultraviolet light, rendering them harmless. Furthermore, the combined use of ultraviolet absorbers (UVA) and light stabilizers (HALS) exhibits a synergistic effect, imparting excellent light resistance to resins.

[0154] For example, hindered amine-based light stabilizers can be used. By adding a light stabilizer (HALS), degradation factors (radicals) generated by ultraviolet light react with and neutralize them, and when used in combination with an ultraviolet absorber (UVA), degradation due to ultraviolet light can be prevented.

[0155] (UV scattering agent) Ultraviolet (UV) scattering agents are small particles that physically reflect or scatter ultraviolet light. Typical UV scattering agents include titanium dioxide, zinc oxide, and cerium oxide.

[0156] By incorporating an ultraviolet scattering agent into the material constituting the acoustic lens and / or acoustic window according to the present invention, ultraviolet rays can be reflected and scattered, thereby preventing discoloration and deterioration of physical properties of the acoustic lens and / or acoustic window made of a material containing polyolefin.

[0157] In particular, when the polyolefin mentioned above is polymethylpentene, which has low UV weather resistance, this is useful in preventing the discoloration and deterioration of physical properties described above.

[0158] Among ultraviolet scattering agents, titanium dioxide in particular is also used as a coloring agent and is used to color plastic products white. For example, consider the case in which the acoustic lens and / or acoustic window according to the present invention is colored white.

[0159] If an organic layer, as described later, is formed on the acoustic lens and / or acoustic window, it is thought that if the ultrasonic probe is scanned on the human body over a long period of time, the organic layer will deteriorate due to wear and UV-C irradiation and eventually peel off.

[0160] In such cases, if the organic layer is colored with a pigment other than white, it can be determined that deterioration has progressed when the white surface of the acoustic lens and / or acoustic window is exposed after the organic layer has peeled off due to abrasion or UV-C irradiation.

[0161] Therefore, since there will be no delay in deciding to repair areas where the organic layer has peeled off, such as by repainting the organic layer, it is possible to prevent interference with the scanning of the human body with the ultrasound probe in advance.

[0162] For the reasons stated above, it is preferable that the acoustic lens and / or acoustic window be colored white with titanium oxide. Furthermore, it is preferable that the organic layer formed on the acoustic lens and / or acoustic window be colored in a color other than white.

[0163] (Coloring agent) Various known colorants can be used, but if the acoustic lens and / or acoustic window is colored black, it is preferable that the organic layer formed on the acoustic lens and / or acoustic window be colored with a colorant other than black, from the viewpoint of confirming the progression of deterioration.

[0164] As a black coloring agent, black pigments such as carbon black or carbon black nanotubes are preferred. Adding carbon black or carbon nanotubes as a coloring agent and ultraviolet absorber to polyolefin-containing materials constituting acoustic lenses and / or acoustic windows is useful.

[0165] Carbon nanotube black bodies, used as carbon black nanotubes, are the closest thing to a black body, utilizing the nanoscale vertical orientation structure of single-walled carbon nanotubes (SWNTs) produced by the super-growth CVD method. Furthermore, they absorb 99% of light (electromagnetic waves) across a wide wavelength range from deep ultraviolet to visible light and far infrared (within the wavelength range of 200 nm to 200 μm), exhibiting three times the performance of conventional materials that are closest to black bodies.

[0166] 5.Organic layer From the viewpoint of enhancing ultraviolet resistance, it is preferable that an organic layer with high ultraviolet resistance is formed on the surface of the acoustic lens and / or acoustic window according to the present invention. Furthermore, from the viewpoint of improving the adhesion between the acoustic lens and / or acoustic window and the organic layer, the surface of the acoustic lens and / or acoustic window may be treated with a primer, plasma treatment, and UV ozone cleaner, etc.

[0167] On the other hand, if an organic layer is formed on the exterior surface of an acoustic window made of polymethylpentene material using a coating agent containing highly UV-resistant acrylic urethane, an acoustic impedance mismatch occurs at the interface between the polymethylpentene material and the coating agent. Furthermore, ultrasonic attenuation occurs due to the coating agent, resulting in a slight decrease in high-frequency sensitivity in the frequency response. However, it exhibits excellent performance in terms of UV-C resistance.

[0168] In this specification, "high UV resistance" refers to, for example, not becoming brittle, not discoloring, not losing elasticity, and not losing fracture strength. For high UV resistance, it is particularly important that the deterioration of mechanical performance is minimal. Specifically, "high UV resistance" means that the acoustic lens or acoustic window does not crack, insulation is ensured, and it fulfills its role of protecting the patient from electrically active transducer elements.

[0169] Materials with high UV resistance include, for example, acrylic, urethane, urethane acrylate, silicone, and paraxylylene polymers (parylene coatings). Generally, the order of resistance is "acrylic < urethane < silicone < fluorine (e.g., paraxylylene polymers)," and these are used in applications requiring high weather resistance in paints.

[0170] Figure 8 is a schematic diagram of an example of an acoustic lens in which an organic layer has been formed.

[0171] A primer 11a is formed on the acoustic lens 11 in Figure 8. Preferably, an organic layer 11b is formed on the acoustic lens 11 via the primer 11a as needed. The organic layer 11b may be composed of multiple layers.

[0172] For example, if an organic layer 11b with high water permeability is formed on the outermost layer of the acoustic lens 11, a primer is applied to the acoustic lens 11 from the viewpoint of improving adhesion with the acoustic lens 11 which is made of a material containing polyolefin. The outermost layer of the acoustic lens 11 is the surface that comes into contact with the body surface of the subject.

[0173] The acoustic lens 11 is required to have a low ultrasonic attenuation coefficient, high affinity (hydrophilicity) to the gel used during diagnosis, and high resistance to disinfectants, etc., due to its role.

[0174] [Implementation] A. Investigation of the frequency characteristics of the ultrasonic sensor (Embodiment 1) Figure 9 shows the frequency characteristics graphs of the ultrasonic sensors in the ultrasonic probes. Figure 9(a) shows the frequency characteristics graphs of conventional and ultraviolet-absorbing ultrasonic sensors, and Figure 9(b) shows the frequency characteristics graphs of conventional and organic layer-forming ultrasonic sensors.

[0175] Figures 9(a) and 9(b) show the frequency characteristics of three types of ultrasonic sensors: a conventional type, a type containing an ultraviolet absorber, and a type forming an organic layer.

[0176] Furthermore, all of these ultrasonic sensors are equipped with an acoustic window, and this acoustic window is made of a material containing polymethylpentene, which is a polyolefin. Hereinafter, "material containing polymethylpentene" will also be simply referred to as "polymethylpentene material."

[0177] As the polymethylpentene used above, we used TPX manufactured by Mitsui Chemicals, Inc. ("TPX" is a registered trademark of Mitsui Chemicals, Inc.).

[0178] (a) Conventional type In Figures 9(a) and 9(b), (a) and (a') represent the frequency characteristics of a conventional ultrasonic sensor.

[0179] Furthermore, the acoustic window in this conventional ultrasonic sensor does not contain an ultraviolet absorber, nor does it have an organic layer. Also, (a) does not contain any pigment, while (a') contains titanium dioxide, a white pigment.

[0180] (b) UV absorber-containing type Figures 9(a) (b-1) and (b-2) show the frequency characteristics of an ultrasonic sensor containing an ultraviolet absorber.

[0181] Furthermore, while the acoustic window of the ultrasonic sensor containing the ultraviolet absorber contains the ultraviolet absorber, no organic layer is formed therein.

[0182] As the UV absorbers mentioned above, (b-1) used BASF's UV absorber [3] "Tinuvin 1577 ED" with a maximum absorption wavelength of 274 nm. The amount of "Tinuvin 1577 ED" added was 0.5% by mass. (b-2) used BASF's UV absorber [4] "Tinuvin 1600" with a maximum absorption wavelength of 320 nm. The amount of "Tinuvin 1600" added was 0.5% by mass.

[0183] (c) Organic layer forming type Figure 9(b)(c) shows the frequency characteristics of an organic layer-forming ultrasonic sensor. Note that although an organic layer is formed in the acoustic window of this organic layer-forming ultrasonic sensor, it does not contain an ultraviolet absorber.

[0184] As for the organic layer mentioned above, (c) is a 30 μm thick organic layer made of acrylic urethane coated on the exterior surface of the acoustic window.

[0185] In addition, (c) uses Fujikura Chemical's "FUJIHARD" undercoat agent [U] and Rock Paint's "Multi Top" two-component curing acrylic urethane paint as the topcoat agent [T].

[0186] B. Examination of the effects of UV absorbers and organic layers (Embodiment 2) The following examines the effects of ultraviolet absorbers and organic layers when materials containing polyolefins are used as components of acoustic lenses and / or acoustic windows. Hereinafter, "materials containing polyolefins" will also be simply referred to as "polyolefin materials."

[0187] In the following study process, the acoustic lenses and / or acoustic windows made of polyolefin material will be those of the (a) conventional type, (b) ultraviolet absorber-containing type, and (c) organic layer-forming type described above.

[0188] (B.1) Observation and evaluation of the acoustic window condition after deep ultraviolet irradiation (a) Conventional type, (b) UV absorber-containing type, and (c) Organic layer-forming type acoustic windows were subjected to 100 hours of UV-C irradiation using a 30W germicidal lamp, and external images of the acoustic windows were captured at 12x magnification using a 3D measuring microscope device manufactured by Keyence Corporation. The condition of the captured external images was then observed, and the acoustic properties and UV-C resistance were evaluated according to the evaluation method and evaluation criteria described below.

[0189] [Method for evaluating acoustic characteristics] In ultrasonic probes equipped with (a) conventional, (b) UV absorber-containing, and (c) organic layer-forming acoustic windows, a piezoelectric transducer was driven by an impulse driver, and numerical values ​​were calculated from the gain of the frequency spectrum of the echo pulse from a stainless steel reflector placed at the acoustic focal length of the acoustic lens.

[0190] [Evaluation Criteria for Acoustic Characteristics] A: The gain at each frequency is the same as that of the conventional type (a) in the comparative example. B: The gain at a specific frequency is more than 2 dB worse than the comparative example (a) of the conventional type.

[0191] [Method for evaluating UV-C resistance] The UV-C resistance of (a) conventional, (b) UV absorber-containing, and (c) organic layer-forming acoustic windows was evaluated by visual inspection to determine the presence or absence of cracks.

[0192] [Evaluation Criteria for UV-C Resistance] A: No cracks, scratches, or streaks are visible on the surface of the acoustic window. B: There are no cracks or scratches on the surface of the acoustic window, but there are streak-like patterns. C: There are scratches on the surface of the acoustic window that do not amount to cracks. D: Cracks are visible in the acoustic window.

[0193] Furthermore, when using a topcoat agent as in this case, the topcoat agent itself may cause discoloration of the polymethylpentene material. To prevent such discoloration, it is advisable to add an ultraviolet absorber or a light stabilizer. Therefore, it is believed that adding an ultraviolet absorber or a light stabilizer to the acoustic lens and / or acoustic window according to the present invention will further improve the acoustic properties and UV-C resistance.

[0194] There are no particular restrictions on the UV absorbers mentioned above, but to give a specific example, one example is "Eversorb" manufactured by Everlight Chemical Co., Ltd. ("Eversorb" is a registered trademark of Everlight Chemical Co., Ltd.).

[0195] Furthermore, there are no particular restrictions on the above-mentioned light stabilizers, but to give a specific example, one example is the anti-UV-C light stabilizer "ST22005" manufactured by Everlight Chemical Co., Ltd.

[0196] Each of the fabricated acoustic windows—(a) conventional type, (b) UV absorber-containing type, and (c) organic layer-forming type—was subjected to UV-C irradiation for 100 hours using a 30W germicidal lamp, and external images of each acoustic window were captured using a 3D measuring microscope device manufactured by Keyence Corporation.

[0197] Figure 10 shows the external appearance of each acoustic window after deep ultraviolet irradiation. In Figure 10, (a) is an external appearance image of a conventional acoustic window, (b-1) is an external appearance image of an acoustic window containing ultraviolet absorber 3, and (b-2) is an external appearance image of an acoustic window containing ultraviolet absorber 4. Furthermore, (a') is an external appearance image of an acoustic window to which titanium dioxide, a white pigment, has been added to a conventional acoustic window, and (c) is an external appearance image of an acoustic window to which an organic layer has been formed on the surface of (a').

[0198] Then, the external appearance of each acoustic window was observed, and its UV-C resistance was evaluated using the evaluation method and criteria described above. Table III shows the evaluation results for each acoustic window.

[0199] [Table 3]

[0200] (B.2) Considerations for each acoustic window (B.2.1) Regarding acoustic windows [a] Cracks were observed on the surface of conventional acoustic windows. This suggests that the polymer bonds in conventional acoustic windows break, leading to cracks on the surface of the acoustic window.

[0201] (B.2.2) Regarding acoustic windows [b-1] No cracks were observed on the surface of the acoustic window [b-1], which is made of a material containing an ultraviolet absorber.

[0202] Here, the majority of the ultraviolet light emitted from the germicidal lamp is deep ultraviolet light with a wavelength of 254 nm. Therefore, it is thought that the reason for using BASF's triazine-based ultraviolet absorber "Tinuvin 1577 ED," which has a high absorption rate of approximately 0.5 for deep ultraviolet light with a wavelength of 254 nm, is that it was used.

[0203] (B.2.3) Regarding acoustic windows [b-2] On the surface of the acoustic window [b-2], which is made of a material containing an ultraviolet absorber, a streak-like pattern was observed.

[0204] This is likely because BASF's triazine-based UV absorber "Tinuvin 1600," which has a relatively low absorption rate of approximately 0.2 for deep ultraviolet light at a wavelength of 254 nm, was used.

[0205] Here, it is believed that the minor imperfections mentioned above can be improved by adding a light stabilizer (HALS). This is based on the idea that by using a material containing a light stabilizer in the material that makes up the acoustic window, the light stabilizer can react with degradation factors (radicals) generated by ultraviolet light and render them harmless. As a result, degradation of the acoustic window due to UV-C irradiation can be suppressed.

[0206] Examples of such light stabilizers include ADEKA's "ADEKA Stab LA series" of light stabilizers for polyolefins.

[0207] (B.2.4) Regarding acoustic windows [a'] On the surface of conventional acoustic windows to which titanium dioxide, a white pigment, was added, scratches that did not result in cracks were observed. Therefore, it is thought that the addition of an ultraviolet scattering agent can suppress the degradation of acoustic windows due to UV-C irradiation.

[0208] (B.2.5) Regarding acoustic windows [c] No cracks were observed on the surface of the acoustic window [c] where the organic layer was formed.

[0209] Cracks in the acoustic lens and / or acoustic window can expose patients to danger from electrically active transducer elements. Therefore, although it involves a trade-off with the high-frequency sensitivity of the ultrasonic sensor, adding protection with an organic layer is effective in preventing UV-C radiation.

[0210] C. Overall assessment As is clear from the above, the examples are superior overall to the comparative examples. This indicates that the acoustic lens and / or acoustic window according to the present invention is less susceptible to deterioration of physical properties due to ultraviolet light, particularly embrittlement. Therefore, an ultrasound probe and ultrasound diagnostic apparatus equipped with the acoustic lens and / or acoustic window according to the present invention can protect the patient from electrically active transducer elements.

[0211] Although embodiments of the present invention have been described and illustrated in detail above, the disclosed embodiments are illustrative and for illustrative purposes only and are not limiting. The scope of the present invention should be interpreted by the terms of the appended claims. [Explanation of symbols]

[0212] 100 Ultrasound diagnostic equipment 1. Ultrasound probe 1a Cable 1b Probe connector 2 Main unit 3 monitors 10 Ultrasonic Sensors 11, 21 Acoustic Lenses 12, 22 laminate 121, 221 Acoustic matching layer 121a 1st matching layer 121b Second matching layer 122, 222 Piezoelectric vibrators 123, 223 Back load material 124 Dividing groove 20 Piezoelectric element unit 30 Acoustic windows 40. Oscillating mechanism 50 Tip storage section 60 Reservoir 70 signal line 80 Grip section 90 Insertion part FPC Flexible Circuit Board GND ground film FL Frame aq Acoustic medium liquid filled in the internal space

Claims

1. A laminate comprising at least a back load material, a piezoelectric vibrator, and an acoustic matching layer, It comprises an acoustic lens and / or acoustic window that contact the body surface of the subject to efficiently transmit ultrasound, The acoustic lens and / or acoustic window is made of a material containing an ultraviolet absorber that absorbs ultraviolet light in the range of at least 100 to 280 nm wavelength and a polyolefin. An ultrasonic probe characterized by the following features.

2. The polyolefin contains at least polymethylpentene. The ultrasonic probe according to feature 1.

3. The maximum absorption wavelength of the UV absorber is in the range of 254 to 325 nm. The ultrasonic probe according to feature 1.

4. The ultrasonic probe according to claim 1, characterized in that the ultraviolet absorber contains at least one or more compounds selected from 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5[2-(2-ethylhexanoyloxy)ethoxy]phenol, 2-[4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine-2-yl]-5-(octyloxy)-phenol, 2-(4,6-diphenyl-1,3,5-triazine-2-yl)-5-(hexyloxy)phenol, [2-hydroxy-4-(octyloxy)phenyl](phenyl)methanone, and 2-[4,6-bis(1,1'-biphenyl-4-yl)-1,3,5-triazine-2-yl]-5-[2-(2-ethylhexyl)oxy)]phenol.

5. An organic layer is formed on the surface of the acoustic lens or the surface of the acoustic window. The aforementioned organic layer has high UV resistance. The ultrasonic probe according to feature 1.

6. The organic layer contains at least one compound from among acrylate, urethane, urethane acrylate, silicone, and paraxylylene polymer. The ultrasonic probe according to feature 5.

7. The aforementioned organic layer contains an ultraviolet absorber and a light stabilizer. The ultrasonic probe according to feature 5.

8. The acoustic lens or the acoustic window contains carbon black or carbon black nanotubes. The ultrasonic probe according to feature 1.

9. The acoustic lens or the acoustic window is colored black. The organic layer is colored with a different color from the acoustic lens or the acoustic window. An ultrasonic probe according to any one of claims 1 to 8.

10. The acoustic lens or the acoustic window contains an ultraviolet scattering agent. The ultrasonic probe according to feature 1.

11. The aforementioned ultraviolet scattering agent contains titanium dioxide, The acoustic lens or the acoustic window is colored white. The organic layer is colored with a different color from the acoustic lens or the acoustic window. The ultrasonic probe according to feature 10.

12. The acoustic wave probe is provided as described in claim 1. An ultrasound diagnostic device characterized by the following features.

Images