Ultrasonic permeable products

Abstract

An ultrasonically transparent material used to transmit ultrasonic energy in medical ultrasound or non-destructive testing (NDT) applications.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing date of U.S. Application No. 63 / 408,490, filed September 21, 2022. The disclosures of the above applications are incorporated herein by reference in their entirety.

[0002] This invention was made with United States Government funding under Contract 75A50121C00035 awarded to the Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority. The United States Government has certain rights in this invention. [Technical Field]

[0003] The present invention relates to ultrasound transparent materials used to transmit ultrasound energy in medical ultrasound or non-destructive testing (NDT) applications. [Background technology]

[0004] Imaging using ultrasonic energy has gained widespread acceptance in medical and nondestructive testing applications. Distance measurement can be achieved by transmitting ultrasonic energy to a patient or test material and measuring the time-of-flight of the reflected ultrasonic echo. Typically, an ultrasonic transducer is placed in direct contact with the imaging target, and a thin layer of liquid or gel is used to transmit the ultrasonic energy from the transducer to the imaging target. However, liquid and gel coupling materials generally cannot provide adequate contact between the ultrasonic transducer and imaging targets with irregularly shaped surfaces. In these cases, it is common to place a thicker, appropriately shaped, ultrasonically transparent material between the ultrasonic transducer and the imaging target to provide adequate contact for the transmission of ultrasonic energy.

[0005] Suitable ultrasound-transmitting materials are typically comprised of thermoplastic or thermoset elastomeric materials, including hydrogels, silicones, polyurethanes, and alkenes. These elastomeric materials typically contain additives, fillers, and plasticizers to tailor the mechanical and acoustic properties of the material. The mechanical properties (including durability, elasticity, hardness, and surface tack) and acoustic properties (including attenuation, acoustic impedance, sound velocity, and acoustic insertion loss) are often tailored to meet the needs of a particular ultrasound imaging application.

[0006] Traditionally, elastomeric acoustically transparent materials have always attempted to approach the acoustic properties of water and gel coupling materials, particularly by matching the ultrasonic velocity in the material and minimizing its attenuation. However, because sound velocity and attenuation are functions of the elasticity and density of the material, the requirement to match these acoustic properties traditionally limits the range of mechanical properties that can be approached. Specifically, the ultrasonic velocity in a material is a function of its elasticity and density. (Number 1) c=sqrt(K / rho) (where c is the speed of sound, K is a measure of the elasticity of the material (e.g., bulk modulus), and rho is the density of the material.) Similarly, the attenuation of ultrasonic energy in a material is controlled by its acoustic impedance, which is a function of the material's density and the speed of sound. (Number 2) Z=rho*c (where Z is the acoustic impedance, rho is the density, and c is the speed of sound.)

[0007] Due to these physical relationships, the mechanical and acoustic properties of elastomeric materials are closely related, and adjusting one parameter typically affects the other. For this reason, it has traditionally been difficult to achieve a wide range of mechanical properties while maintaining desirable acoustic properties with a single category of elastomeric materials. Consequently, the field relies on a variety of different material formulations to meet the different sound transmission requirements of medical and nondestructive testing applications.

[0008] To overcome the drawbacks of prior art methods for producing sound-transmitting materials with a broad range of mechanical properties and a narrow range of acoustic properties, the present invention describes a method for producing polyurethane gel formulations based on a reaction mixture containing an isocyanate (NCO) prepolymer, a specific polyol containing groups reactive with these isocyanate groups, and an organic plasticizer. Adjusting the composition of the reaction mixture of the present invention produces polyurethanes that exhibit stiffness variations from approximately Shore A 50 to less than Shore A 000 (i.e., a 10X to 1000X difference in modulus), while exhibiting less than a 5% change in the sound velocity, acoustic impedance, and acoustic attenuation of the material. For sound-transmitting applications, including medical diagnostic imaging, desirable material properties are those matching the velocity and impedance of soft tissue, i.e., approximately 1540 m / s and 1.5 MRayls, respectively. In many cases, the desired attenuation is as low as possible, or at least lower than the attenuation of human soft tissue, or less than 1.0 dB / MHz-cm.

[0009] Additionally, as described herein, the surface properties of the materials of the present invention can be controlled from no surface tack to very high surface tack, which may be required for each unique application requiring the use of an acoustically transparent material. The materials described herein may also be bonded to other materials (including silicone rubber, urethane rubber, metal, and semi-rigid plastics), thereby providing a pathway for integrating the materials into multi-layer acoustically coupled assemblies, which may be required for each unique application. The following describes examples of the present invention. Summary of the Invention [Problem to be solved by the invention]

[0010] The exemplary embodiments described herein have novel features, and no single feature is essential or individually responsible for its desirable attributes. The following description and drawings specifically describe some exemplary embodiments of the present disclosure and show some exemplary forms in which various principles of the present disclosure may be implemented. However, these schematic illustrations are not limited to the many possible embodiments of the present disclosure. Without limiting the scope of the claims, some advantages are summarized. Other objects, advantages, and novel features of the present disclosure will be described in the following detailed description of the present disclosure with reference to the drawings, which are intended to illustrate, not limit, the present invention. [Means for solving the problem]

[0011] The present invention overcomes the problems of conventional elastomeric sound-transmitting materials. In embodiments, the present invention provides a method for preparing polyurethane-based sound-transmitting materials, which have a wide range of mechanical properties and a narrow range of acoustic properties, and which are customized for sound transmission in medical, non-destructive testing, sonar, and other acoustic applications. [Brief explanation of the drawings]

[0012] The drawings illustrate some embodiments and aspects of the present invention and should not be used to limit or restrict the present invention. These drawings, together with the description herein, are used to explain some principles of the present invention. For a more complete understanding of the nature and advantages of the present invention, please refer to the following detailed description of the preferred embodiments in conjunction with the drawings. [Figure 1] 1 is a schematic diagram of an exemplary acoustically transparent mat for transmitting ultrasonic energy into a receiving body in a medical application in accordance with an embodiment of the present invention. [Figure 2] 1 illustrates an acoustically transparent device comprising multiple components for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention, one of the components being an acoustic couplant that contributes to transmitting ultrasonic energy into a receiving body through an acoustically transparent pad in a medical application. [Figure 3] 1 illustrates an acoustically transparent device for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention, the device comprising multiple components, one of which is an acoustic couplant that contributes to transmitting ultrasonic energy into a receiving body through an acoustically transparent pad in a medical application, and one of which is an acoustically transparent protective layer. [Figure 4] 1 illustrates an acoustically transparent device for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention, the device comprising multiple components, one of which is an acoustic couplant that contributes to transmitting ultrasonic energy into a receiving body through an acoustically transparent pad in a medical application, and one of which is an acoustically transparent protective layer that packages the acoustically transparent pad. [Figure 5] 1 illustrates a multi-component acoustically transparent device for transmitting ultrasonic energy into a receiving body in a non-destructive testing application according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] Various exemplary embodiments of the present invention are described in detail below. It should be noted that the following descriptions of the exemplary embodiments are not intended to limit the present invention. Rather, the following descriptions are provided to provide the reader with a more detailed understanding of certain aspects and features of the present invention.

[0014] The present invention relates to the formulation of polymeric acoustically transparent materials based on a reaction mixture of a prepolymer of isocyanate (NCO), a polyol having OH functional groups reactive to the NCO groups, an organic plasticizer and a filler. The present invention describes a process for producing these acoustically transparent materials and acoustic coupling devices / products containing these acoustically transparent materials.

[0015] The physical, acoustic, and mechanical properties of polyurethanes can be varied by modifying the composition of the reaction mixture and reaction conditions. Polyurethanes can be rigid or flexible, as their polymer structure consists of soft and hard segments. The soft segments are formed by high-molecular-weight polyols, which affect the polyurethane's flexibility and elastic properties, while the hard segments are formed by isocyanates and crosslinkers, which affect its rigidity and durability. Generally, lowering the NCO:OH molar ratio in the cured polymer reduces crosslinking within the polymer network, increasing the polyurethane's elasticity, flexibility, and softness. However, to form a soft polyurethane gel, the NCO:OH molar ratio must be high enough to form a crosslinked polymer network, yet low enough to generate unreacted polyol chains, resulting in gel-like relaxation behavior. Depending on the specific formulation, a lower limit for the NCO:OH molar ratio of approximately 0.1 produces a soft, liquid-like gel with a hardness exceeding the Shore OOO scale.

[0016] In addition to lowering the NCO:OH ratio, the physical properties of polyurethanes can also be adjusted by adding organic plasticizers. Internal plasticizers are flexible monomers that bond directly to the polymer chain, while external plasticizers are materials that physically interact with the elastomer but do not chemically react with the polymer. External plasticizers offer the greatest latitude in tailoring specific compound properties, but are known to migrate and leach out of the material over time. According to the present invention, the use of plasticizers can achieve softer, more flexible polyurethanes than those with a specific NCO:OH ratio. In embodiments, polyurethane gels can be composed of very high proportions of plasticizer, with particularly soft gels containing more than 50% plasticizer by weight.

[0017] Suitable isocyanates for preparing the prepolymer reaction mixture are aliphatic, cycloaliphatic, or aromatic polyisocyanates with an NCO functionality of 2 to 5, preferably 2.5 to 4. When optical clarity and weatherability are required, aliphatic isocyanates are preferred because they have higher resistance to ultraviolet light and improved durability and toughness compared to aromatic polyisocyanates. Examples of suitable polyisocyanates include, but are not limited to, diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), tolylene diisocyanate (TDI), isophorone diisocyanate (IPDI), and optionally modified polymer compositions containing biuret and trimer, or combinations thereof.

[0018] Polyols suitable for reaction with isocyanates include polyols with a functionality of 1 to 6 and a molecular weight of 1,000 to 20,000. While several types of polyether or polyester polyols can be used to form polyurethanes, polyether or polyester polyols with a functionality close to 2, a molecular weight of 1,000 to 5,000, a linear polyether backbone structure, and a vinyl content of 5% to 60% are preferred to achieve flexible polyurethane gels. A higher vinyl content imparts greater flexibility to the chain and results in better compatibility with other polyols (particularly polypropylene glycol (PPG) and polytetramethylene ether glycol (PTMEG)). This improved compatibility allows for the preparation of mixed prepolymers by blending polyols. Examples of suitable polyols include, but are not limited to, polyhydroxypolyethers, polyhydroxypolyesters, polyhydroxypolyacetals, polyhydroxypolyesteramides, polyhydroxypolyamides, polyhydroxypolybutadienes, and mixtures thereof.

[0019] Preferably, the external plasticizer is bonded to the acoustically transparent material because it does not significantly compromise the integrity of the polymer network. Suitable external plasticizers for bonding to the acoustically transparent material include those with long linear aliphatic backbones that promote retention in the hydrophobic polymer network and impart high flexibility to the polyurethane elastomer. Examples of suitable plasticizers include, but are not limited to, di-n-heptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), diisooctyl phthalate (DIOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), diisodecyl glutarate (DIDG), di-n-butyl sebacate (DBS), diisodecyl adipate (DIDA), dibutoxyethyl adipate (DBEA), dibutoxyethoxyethyl sebacate (DBEES), trioctyl trimellitate (TOTM), and dioctyl terephthalate (DOTP). Preferably, phenyl, biphenyl, terphenyl, toluene, xylene, and other alkyl benzenes are attached to provide a highly fluid external plasticizer within the elastomer, which also gives the elastomer more flexibility and the ability to self-heal after breakage or damage.

[0020] The NCO:OH molar ratio used in producing the acoustically transparent material may range from 0.1 to 4, but is preferably 0.5 to 2. In the absence of a plasticizer, a low NCO:OH molar ratio (i.e., less than 1.0) results in a weakly crosslinked polyurethane gel that is unable to retain its shape and exhibits high surface tack. Higher NCO:OH ratios (i.e., greater than 1.0) are preferably used to produce a fully crosslinked polymer network, with the use of internal and / or external plasticizers to achieve the desired physical, mechanical, and acoustic properties.

[0021] Polyurethanes can be prepared using either a one-shot process or a prepolymer process. For example, in the one-shot process, all components are added to the reaction mixture simultaneously and mixed. For example, in the prepolymer process, the entire amount of isocyanate is first reacted with a portion of the polyol to form a liquid prepolymer with a reduced free isocyanate content of 1% to 15% by weight, and then the liquid prepolymer is reacted with the remaining polyol, plasticizer, and catalyst to produce an elastomer. The advantages of using the prepolymer process are reduced reaction exotherm, improved isocyanate processability, and improved mixing during the secondary reaction. Either of these two processes can be used to prepare acoustic coupling materials.

[0022] The acoustically transparent material may be integrated into an acoustically transparent device for medical, non-destructive testing, sonar, or other acoustically transparent applications. In this embodiment, the acoustically transparent material may be cured in a physical mold and then demolded to impart the shape required for the end use.

[0023] 1 shows a polyurethane acoustically transparent material 100 acoustically coupled to an ultrasound transducer 102 and a receiving body 104 having an internal feature 106 that is the subject of acoustic interrogation. The polyurethane acoustically transparent material 100 may be configured with a surface tack that provides acoustic coupling between the ultrasound transducer 102, the polyurethane acoustically transparent material 100, and the receiving body 104 (which may include a patient's anatomy or a non-destructive test sample).

[0024] 2, acoustic coupling material 200 is applied to the surface of polyurethane acoustically transparent material 100 to provide acoustic coupling between ultrasound transducer 102, polyurethane acoustically transparent material 100, and receiving body 104. Acoustic coupling material 200 may include an aqueous or non-aqueous mobile phase, preferably water, acoustic coupling gel, hydrogel, water-based lubricant, synthetic lubricant, mineral oil, or petroleum-based lubricant. Acoustic coupling material 200 may also include an adhesive to temporarily or permanently attach polyurethane acoustically transparent material 100 to ultrasound transducer 102 and / or receiving body 104.

[0025] In a preferred embodiment shown in FIG. 3, the acoustically transparent material 100 can be directly integrated into a multi-component device. One exemplary embodiment is a medical ultrasound device having a biocompatible exterior surface material 300 and an interior space filled with a polyurethane-based acoustically transparent material 100. The biocompatible surface may comprise polyurethane, cured silicone, or at least one plastic selected from the group consisting of polymethylpentene, cross-linked polystyrene and divinylbenzene, polypropylene, polyether block amide, polyester, polyethylene, polyethylene terephthalate, nylon, and polyimide. The acoustically transparent material 100 can be cured between the ultrasound transducer 102 and the biocompatible surface 300 to provide a pathway for transmitting ultrasound energy from the ultrasound transducer 102 to the biocompatible surface 300 and ultimately to the patient's body 104.

[0026] In the embodiment shown in FIG. 4 , acoustically transparent material 100 can be integrated directly into a multi-component device, with biocompatible exterior surface material 400 encapsulating the entire polyurethane-based acoustically transparent material 100. The biocompatible surface can include polyurethane, cured silicone, or at least one plastic selected from the group consisting of polymethylpentene, cross-linked polystyrene and divinylbenzene, polypropylene, polyether block amide, polyester, polyethylene, polyethylene terephthalate, nylon, and polyimide. Acoustic coupling material 200 can be applied to the surface of biocompatible exterior surface 400 to provide acoustic coupling between ultrasound transducer 102, the multi-component device including polyurethane acoustically transparent material 100 and biocompatible exterior surface 400, and receiver 104. Acoustic coupling material 200 can include an aqueous or non-aqueous mobile phase, preferably water, acoustic coupling gel, hydrogel, water-based lubricant, synthetic lubricant, mineral oil, or petroleum-based lubricant. The acoustic coupling material 200 may include an adhesive material that temporarily or permanently attaches the biocompatible outer surface 400 to the ultrasound transducer 102 and / or receiver 104 .

[0027] In the embodiment shown in FIG. 5 , the nondestructive testing acoustic coupling device includes an exterior coating layer 300 and an interior space, where the exterior coating layer 300 is stabilizable against harsh chemical exposure, and the interior space is filled with an acoustically transparent material 100. In this embodiment, the acoustically transparent material 100 is used as a delay line between a nondestructive testing acoustic transducer 302 and a device 304 undergoing nondestructive testing. The acoustically transparent material 100 can be engaged with the device 304 undergoing nondestructive testing by temporarily or permanently attaching it to the nondestructive testing equipment 304 using one or more adhesive materials. The acoustically transparent material 100 can be engaged with the device 304 undergoing nondestructive testing by a mechanical engagement mechanism (e.g., including clamps and fasteners). The acoustically transparent material 100 can be engaged with the device 304 undergoing nondestructive testing by attaching a mechanical engagement mechanism between the exterior coating layer 300 and the device 304 undergoing nondestructive testing.

[0028] In these multi-component device embodiments, the polyurethane acoustically transparent material is cured within the voids within the device and is not removed. Polyurethane can exhibit adhesion to the surfaces of other materials in the device, and as known to those skilled in the art, adhesion can be improved through the use of primers (including, for example, one or more silane-based primers), the properties of which are selected based on the material.

[0029] The acoustically transparent material may optionally be combined with additives to impart other desired properties. In an exemplary embodiment, the acoustically transparent material formulation may include trace amounts of a colorant (e.g., titanium dioxide) to change the color of the material. In a single embodiment, the acoustically transparent material formulation may include a particulate filler (e.g., silica particulate) to change the acoustic scattering properties of the material.

[0030] Example The following isocyanates and mixed polyols were used to prepare polyurethane-based sound-transmitting materials by a one-shot process. The physical, acoustic and mechanical properties are shown in Table 1.

[0031] Polyurethane #1: Polyhexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available), and hydroxyl-terminated polybutadiene (Krasol LBH2000, Cray Valley TM ) and polypropylene glycol (Arcol PPG 2000, purchased from Covestro TM A mixture of polyols consisting of ethylenediaminetetraacetic acid (purchased from Epson Corporation) and ethylenediaminetetraacetic acid (ethylenediaminetetraacetic acid) was reacted at an NCO:OH ratio of 1.6. The resulting mixture had a hydroxyl functionality of 2, a viscosity of 450 cps, and a density of approximately 0.95 g / ml. The mixture was catalyzed by dibutyltin dilaurate (DBTDL) and 20% (w / w) diundecyl phthalate (DUP, Palatinol 111P) and cured at 80°C for 2 hours.

[0032] Polyurethane #2: Polyhexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available), and hydroxyl-terminated polybutadiene (Krasol LBH2000, Cray Valley TM (commercially available from Covestro) and polypropylene glycol (Arcol PPG 2000, Covestro) TM A mixed polyol consisting of ethylenediaminetetraacetic acid (commercially available from Epson Corporation) and ethylenediaminetetraacetic acid (European Chemical Industry Co., Ltd.) was reacted at an NCO:OH ratio of 1.2. The resulting mixture had a hydroxyl functionality of 2, a viscosity of 450 cps, and a density of approximately 0.95 g / ml. The mixture was catalyzed by dibutyltin dilaurate (DBTDL) and 20% (w / w) diundecyl phthalate (DUP, Palatinol 111P), and cured at 80°C for 2 hours.

[0033] Polyurethane #3: Polyhexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available), and hydroxyl-terminated polybutadiene (Krasol LBH2000, Cray Valley TM ) and polypropylene glycol (Arcol PPG 2000, purchased from Covestro TM A mixture of polyols consisting of diundecyl phthalate (DUP, Palatinol 111P, BASF) and dibutyltin dilaurate (DBTDL) was reacted at an NCO:OH ratio of 1.2. The resulting mixture had a hydroxyl functionality of 2, a viscosity of 450 cps, and a density of approximately 0.95 g / ml. The catalyst was dibutyltin dilaurate (DBTDL) and diundecyl phthalate (DUP, Palatinol 111P, BASF). TM (purchased from Epson Corporation) was added at 20% (w / w), and terphenyl (Paratherm HT) was added at 5% (w / w), and the mixture was cured at 80°C for 2 hours.

[0034] Polyurethane #4: Polyhexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available), and hydroxyl-terminated polybutadiene (Krasol LBH2000, Cray Valley TM ) and polypropylene glycol (Arcol PPG 2000, purchased from Covestro TMA mixture of polyols consisting of diundecyl phthalate (DUP, Palatinol 111P, BASF) and methyl phthalate (PAL) was reacted at an NCO:OH ratio of 1.0. The resulting mixture had a hydroxyl functionality of 2, a viscosity of 450 cps, and a density of approximately 0.95 g / ml. Dibutyltin dilaurate (DBTDL) was used as a catalyst, and diundecyl phthalate (DUP, Palatinol 111P, BASF) was used. TM (purchased from Epson Corporation) was added at 20% (w / w), and terphenyl (Paratherm HT) was added at 10% (w / w), and the mixture was cured at 80°C for 2 hours.

[0035] [Table 1] Table 1: Examples of physical and acoustic properties of sound-transmitting materials Polyurethanes #1 to #4.

[0036] Polyurethane #5: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol with 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, Tandem Products, Inc.). TM A mixture of polyols consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted at an NCO:OH ratio of 1.66. 12.73% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0037] Polyurethane #6: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol with 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, Tandem Products, Inc.). TMA mixture of polyols consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted at an NCO:OH ratio of 1.66. 21.31% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0038] Polyurethane #7: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol with 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, Tandem Products, Inc. TM A mixed polyol consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted with the polyol at an NCO:OH ratio of 1.66. 29.41% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0039] Polyurethane #8: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol with 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, Tandem Products, Inc. TM A mixture of polyols consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted at an NCO:OH ratio of 1.66. 36.00% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0040] Polyurethane #9: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol with 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, Tandem Products, Inc.). TMA mixture of polyols consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted at an NCO:OH ratio of 1.66. 45.45% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0041] Polyurethane #10: Hexamethylene diisocyanate oligomer, isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), and poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and defoamer (GNX-271RVN13, Tandem Products, Inc.). TM A mixture of polyols consisting of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (purchased from Epson Corporation) was reacted at an NCO:OH ratio of 1.66. 48.94% (w / w) of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate was added and cured at 75°C for 1 hour.

[0042] [Table 2] Table 2: Examples of physical and acoustic properties of sound-transmitting materials Polyurethanes #5 to #7.

[0043] [Table 3] Table 3: Examples of physical and acoustic properties of sound-transmitting materials Polyurethane #8 to #10.

[0044] Embodiments of the present invention further include a computer-readable medium containing one or more computer files, which contain a set of computer-executable instructions and are used to perform one or more calculations, steps, processes, and operations described or discussed herein. In exemplary embodiments, the files may be stored contiguously or non-contiguously on the computer-readable medium. Embodiments may also include a computer program product, which may be in the form of a computer file or a computer-readable medium containing the computer file, and may optionally be provided to a consumer via packaging or, alternatively, electronic distribution. As used in the context of this specification, a "computer-readable medium" refers to a non-transitory computer-readable medium and includes any type of computer memory, such as a floppy disk, a conventional hard disk, a CD-ROM, a flash ROM, a non-volatile ROM, an EEPROM (electrically erasable programmable read-only memory), and a RAM. In exemplary embodiments, the computer-readable medium has a set of instructions stored thereon that, when executed by a processor, causes the processor to perform tasks based on data stored in an electronic database or memory as described herein. The processor may implement the process by any of the programs discussed in this disclosure or any equivalent program.

[0045] In other embodiments of the present invention, a file containing a set of computer-executable instructions may be stored in computer-readable memory on a single computer or may be distributed among multiple computers. From this disclosure, it will be apparent to those skilled in the art that the present invention may be implemented in hardware or firmware in addition to software. Thus, as used herein, the operations of the present invention may be implemented in a system including a combination of software, hardware, or firmware.

[0046] Embodiments of the present disclosure include one or more computers or devices loaded with a set of computer-executable instructions described herein. The computer or device may be a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus for producing a specific machine, where one or more computers or devices are instructed and configured to perform the calculations, processes, steps, operations, algorithms, statistical methods, formulas, or computational routines of the present disclosure. A computer or device that performs a specified calculation, process, step, operation, algorithm, statistical method, formula, or computational routine of the present disclosure may include at least one processing element, such as a central processing unit (i.e., processor), and computer-readable memory, which may include random access memory (RAM) or read-only memory (ROM). The computer-executable instructions can be embedded in computer hardware or stored in computer-readable memory, thereby directing the computer or device to perform one or more calculations, steps, processes, and operations described herein.

[0047] Another embodiment of the present disclosure includes a computer system for performing the computer-implemented methods of the present disclosure. The computer system may include a processor for executing computer-executable instructions, one or more electronic databases containing the data or information described herein, an input / output interface or user interface, and an instruction set (e.g., software) for performing the methods. The computer system may include a standalone computer such as a desktop computer, a portable computer such as a tablet computer, a notebook computer, a PDA, or a smartphone, or a group of computers connected via a network including a client-server arrangement and one or more database servers. The network may use any suitable network protocol, including IP, UDP, or ICMP, and may be any suitable wired or wireless network, including any local area network, wide area network, the Internet, a telecommunications network, a network supporting Wi-Fi, or a network supporting Bluetooth. In one embodiment, the computer system includes a central computer connected to the Internet, having computer-executable instructions stored in a memory operably connected to an internal electronic database. The central computer may execute the computer-implemented methods based on input and instructions received from remote computers via the Internet. A central computer is utilized as a server and remote computers are used as client computers to establish a server-client relationship, and the client computers can send queries from the server and receive output from the server over the network.

[0048] The input / output interface may include a graphical user interface (GUI) that can be used in combination with computer-executable code and an electronic database. The graphical user interface may use text fields, check boxes, pull-down menus, command buttons, and the like to allow a user to perform these tasks. Those skilled in the art will understand how to implement such graphical features to perform the tasks of the present disclosure. The user interface may optionally be accessed from a computer connected to the Internet. In one embodiment, the user interface may be accessed by entering an Internet address through an industry-standard web browser and logging into the web page. The user interface may then be operated by a remote computer (client computer) accessing the web page, submitting searches, and receiving output from the server over a network connection.

[0049] The present invention has been described in detail above with reference to specific embodiments having various features. In light of the disclosure provided above, those skilled in the art will recognize that various changes and modifications can be made in the practice of the present invention without departing from the scope or spirit of the invention. Those skilled in the art will recognize that the disclosed features can be used alone, in any combination, or omitted depending on the requirements and criteria of a particular application or design. When an embodiment is referred to as "comprising" certain features, it should be understood that the embodiment can alternatively be referred to as "consisting of any one or more features" or "consisting essentially of any one or more features." Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention.

[0050] It should be noted that when a range of numerical values ​​is provided herein, each value between the upper and lower limits of that range is also specifically disclosed. The upper and lower limits of these smaller ranges may or may not independently be included within the range. The singular forms "a," "one," and "the" include plural references unless the context clearly dictates otherwise. The specification and examples are illustrative, and variations that do not depart from the essence of the invention are within the scope of the invention. In addition, all references cited in this disclosure are incorporated herein by reference in their entirety, and are intended to provide an effective means of supplementing the disclosure of the invention and to provide a background that will further illustrate the general level of skill in the art.

[0051] As used herein, the term "about" refers to plus or minus 5 units (eg, percentages) of the value stated.

[0052] References in the specification to "some embodiments," "embodiments," "one embodiment," or "other embodiments" mean that a particular feature, structure, or characteristic described with reference to an embodiment is included in at least some embodiments of the invention, but not necessarily in all embodiments.

[0053] As used herein, the terms "basic" and "essentially" refer to content that would be readily recognizable to one skilled in the art.

[0054] It is to be understood that the words and terminology used herein are not to be construed as limiting and are used for descriptive purposes only.

[0055] It should be noted that while some illustrations and drawings may approximate proper proportions, many illustrations and drawings are not intended to be to proper proportions.

[0056] It should be understood that the details described herein do not limit the application of the invention.

[0057] This invention may be practiced or practiced in various ways and may be practiced in forms other than those described above.

Claims

1. 1. An acoustic coupling product for transmitting acoustic signals, comprising an elastomeric material conformable to the surface of one or more receiving bodies, at least one acoustic signal transducer is acoustically coupled to the elastomeric material to transmit acoustic energy generated by the at least one acoustic signal transducer through the elastomeric material to a receiver; The elastomeric material comprises a mixture of at least two polymerizable materials, the ratio of the at least two polymerizable materials being used to adjust the Shore hardness within a range of Shore A50 to Shore OOO 0, and to have an acoustic attenuation coefficient of 3.0 dB / MHz-cm or less.

2. 10. The acoustic coupling product of claim 1, wherein the ratio of the at least two polymerizable materials is adjustable so that the longitudinal sound velocity of the acoustic coupling is in the range of 1000 m / s to 1850 m / s at 25°C.

3. 10. The acoustic coupling article of claim 1, wherein the ratio of the at least two polymerizable materials is adjustable so that the acoustic impedance of the elastomeric material is in the range of 1.0 MRayl to 3.0 MRayl.

4. The density of the elastomeric material is 0.5 g / cm ３ ~1.5g / cm ３ 10. The acoustic coupling product of claim 1, wherein the acoustic coupling coefficient is in the range of

5. at least one of the at least two polymerizable materials in the mixture of the at least two polymerizable materials is a polyurethane; The polyurethane comprises at least one polyol selected from polyhydroxypolyethers, polyhydroxypolyesters, polyhydroxypolyacetals, polyhydroxypolyesteramides, polyhydroxypolyamides, polyhydroxypolybutadienes, and combinations or mixtures thereof; and at least one isocyanate or a composition comprising at least one isocyanate selected from diphenylmethane diisocyanate, hexamethylene diisocyanate, tolylene diisocyanate, isophorone diisocyanate, optionally modified polymer compositions, and combinations or mixtures thereof; 10. The acoustic coupling product of claim 1, optionally including at least one additive selected from at least one colorant, at least one particulate filler, and combinations or mixtures thereof.

6. 1. An acoustic bonding product further comprising at least one plasticizer, adding at least one plasticizer to or combining with the polyurethane to adjust the Shore hardness, density, acoustic properties, and self-healing properties after tearing; 6. The acoustic coupling product of claim 5, wherein the at least one plasticizer comprises at least one selected from di-n-heptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), diisooctyl phthalate (DIOP), diisononyl phthalate (DINP), diisodecyl phthalate (DIDP), diundecyl phthalate (DUP), diisodecyl glutarate (DIDG), di-n-butyl sebacate (DBS), diisodecyl adipate (DIDA), dibutoxyethyl adipate (DBEA), dibutoxyethoxyethyl sebacate (DBEES), trioctyl trimellitate (TOTM), dioctyl terephthalate (DOTP), phenyl, biphenyl, terphenyl, toluene, xylene, alkyl benzene, and combinations or mixtures thereof.

7. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is moldable into a three-dimensional shape, and the molded elastomeric material essentially or largely maintains the three-dimensional shape during use or processing.

8. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is capable of retaining its mechanical and acoustic properties for more than five years.

9. 10. The acoustic coupling product of claim 1, wherein the elastomeric material does not significantly degrade upon dehydration, requires no maintenance, and retains its mechanical and acoustic properties for five years or more.

10. The acoustic coupling product of claim 1 , wherein the surface of the at least one receiver is a surface or structural material that has been subjected to non-destructive testing.

11. 10. The acoustic coupling product of claim 1, wherein the surface of the at least one receiving body is a surface of an anatomical region of the human body including at least one of an arm, a leg, a torso, a pelvis, a back, a shoulder, a neck, a head, an abdomen, a chest, a knee, an elbow, a foot, an ankle, a hand, a wrist, a finger, or a toe.

12. 12. The acoustic coupling product of claim 11, wherein the anatomical region of the human body is at least one of an arm, a leg, a torso, a pelvis, a back, a shoulder, a neck, a head, an abdomen, a chest, a knee, an elbow, a foot, an ankle, a hand, a wrist, a finger, or a toe.

13. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is temporarily attached to the surface of the at least one receiving body, the surface of the at least one acoustic signal transducer, or both the surface of the at least one receiving body and the surface of the at least one acoustic signal transducer by a mechanical engagement mechanism or an adhesive material.

14. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is permanently attached to a surface of the at least one acoustic signal transducer by a mechanical engagement mechanism or an adhesive material.

15. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is acoustically coupled to the surface of the at least one receiving body, the surface of the at least one acoustic signal transducer, or both the surface of the at least one receiving body and the surface of the at least one acoustic signal transducer by a couplant.

16. 16. The acoustic coupling product of claim 15, wherein the couplant is an aqueous couplant.

17. 17. The acoustic coupling product of claim 16, wherein the aqueous couplant comprises one or more of an acoustic gel, water, a saline solution, or a hydrogel.

18. 10. The acoustic coupling product of claim 1, wherein the elastomeric material is acoustically coupled to the surface of the at least one receiving body, the surface of the at least one acoustic signal transducer, or the surface of the at least one receiving body and the surface of the at least one acoustic signal transducer by a non-aqueous couplant.

19. 20. The acoustic coupling product of claim 18, wherein the non-aqueous couplant comprises one or more of a synthetic lubricant, a silicone-based lubricant, a mineral oil, or a petroleum-based lubricant.

20. The acoustic coupling article of claim 1 , wherein the elastomeric material is optically transparent or optically translucent.

21. 10. The acoustic bonding product of claim 1, wherein a surface of the elastomeric material is bonded to at least one of a silicone rubber, a urethane rubber, or a semi-rigid thermoplastic, and the at least one of the silicone rubber, the urethane rubber, or a semi-rigid thermoplastic is optionally applied with a silyl surface primer on the surface of the elastomeric material to form a multi-layer acoustic bonding product.

22. 22. The acoustic coupling product of claim 21, wherein the multilayer acoustic coupling product is temporarily attached to the surface of the at least one receiver, the surface of the at least one acoustic signal transducer, or both the surface of the at least one receiver and the surface of the at least one acoustic signal transducer by a mechanical engagement mechanism or an adhesive material.

23. 22. The acoustic coupling product of claim 21, wherein the multi-layer acoustic coupling product is permanently attached to a surface of the at least one acoustic signal transducer by a mechanical engagement mechanism or an adhesive material.

24. 22. The acoustic coupling product of claim 21, wherein the multilayer acoustic coupling product is acoustically coupled to the surface of the at least one receiving body, the surface of the at least one acoustic signal transducer, or both the surface of the at least one receiving body and the surface of the at least one acoustic signal transducer by an aqueous couplant.

25. 22. The acoustic coupling product of claim 21, wherein the multilayer acoustic coupling product is acoustically coupled to the surface of the at least one receiving body, the surface of the at least one acoustic signal transducer, or both the surface of the at least one receiving body and the surface of the at least one acoustic signal transducer by a non-aqueous couplant.

26. 22. The acoustic coupling product of claim 21, wherein the surface of the at least one receiving body is a surface of an anatomical region of the human body.

27. 22. The acoustic coupling product of claim 21, wherein the surface of the at least one receiver is a surface or structural material that has been subjected to non-destructive testing.

28. 22. The acoustic coupling product of claim 21, wherein the elastomeric material and other materials bonded thereto are optically transparent or optically translucent.

29. 1. An acoustically transparent signaling composition comprising a specific proportion of polymerizable material, wherein the NCO:OH molar ratio is between 0.8 and 2.0 through the selection of an isocyanate prepolymer and a polyol, and the % (w / w) of premixed plasticizer is between 10% and 60%, wherein the specific proportion is used to adjust the Shore hardness to 50 Shore A or less, and wherein the specific proportion provides an acoustic attenuation coefficient of 3.0 dB / MHz-cm or less.

30. 1. An elastomeric material comprising a mixture of at least two polymerizable materials, wherein the ratio of the at least two polymerizable materials can be varied during synthesis of the elastomeric material, wherein varying the ratio of the at least two polymerizable materials changes the viscosity or hardness of the elastomeric material, and wherein the change in viscosity or hardness of the elastomeric material does not increase or decrease the sound velocity, acoustic impedance, and acoustic attenuation of the elastomeric material by more than 5%.

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