Ultrasound transmissive article

Abstract

An ultrasound transmissive material useful for transmitting ultrasonic energy in medical ultrasound or non-destructive testing (NDT) applications, and an acoustic coupling article for acoustic signal transmission, comprising an elastomeric material capable of conforming to a surface of one or more receptors, are claimed herein. The 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 into the receiver, where the elastomeric material comprises a mixture of two or more polymerizable materials. In embodiments, the present invention proposes a method for formulating polyurethane-based acoustically transmissive materials having a wide range of mechanical properties and a narrow range of acoustic properties, which are tailored for acoustic transmission in medical, non-destructive testing, sonar, and other acoustic applications.

Description

[0001] Cross - reference to related applications This application claims the benefit of priority and the filing date of U.S. Application No. 63 / 408,490, filed on September 21, 2022, the disclosure of which is hereby incorporated by reference in its entirety.

[0002] The disclosure of the above - mentioned application is hereby incorporated by reference in its entirety.

[0003] Statement regarding federally - sponsored research in the United States This invention was made with government support under Contract No. 75A50121C00035, awarded by the Biomedical Advanced Research and Development Authority, Office of the Assistant Secretary for Preparedness and Response, U.S. Department of Health and Human Services. The U.S. government has certain rights in this invention. Technical field

[0004] The present invention relates to an ultrasonic transmission material that can be used to transmit ultrasonic energy in medical ultrasound or non - destructive testing (NDT) applications. Background art

[0005] In medical and non - destructive testing applications, using ultrasonic energy for imaging is widely recognized. Distance measurement can be achieved by transmitting ultrasonic energy to a patient or a test material and measuring the flight time 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 into the imaging target. However, liquid and gel coupling materials often do not provide a proper contact between the ultrasonic transducer and an imaging target with an irregular - shaped surface. In these cases, a thicker, conformable ultrasonic transmission material is usually placed between the ultrasonic transducer and the imaging target to provide a contact suitable for the transmission of ultrasonic energy.

[0006] Conformable ultrasonic transmission materials are typically composed of thermoplastic or thermosetting elastomeric materials, including hydrogels, silicones, polyurethanes, and olefins. These elastomeric materials usually include additives, fillers, and plasticizers to adjust the mechanical and acoustic properties of the material. The mechanical properties (including durability, elasticity, hardness, and surface tackiness) and acoustic properties (including attenuation, acoustic impedance, sound velocity, and acoustic insertion loss) are often adjusted to meet the requirements of specific ultrasonic imaging applications.

[0007] Traditionally, elastomeric acoustic transmission materials have been attempting to approximate the acoustic properties of water and gel coupling materials. Of particular importance is to match the speed of ultrasonic waves in the material and minimize its attenuation. However, since the speed of sound and attenuation are functions of the elasticity and density of the material, the requirements for matching these acoustic properties have traditionally limited the accessible range of the mechanical properties of the material. Specifically, the speed of ultrasonic waves in the material is a function of its elasticity and density, i.e., c = sqrt(K / rho), where c is the speed of sound waves, 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 wave energy in the material is controlled by its acoustic impedance, which is a function of the density and speed of sound of the material, i.e., , where Z is the acoustic impedance, rho is the density, and c is the speed of sound.

[0008] Due to these physical relationships, the mechanical properties and acoustic properties of elastomeric materials are closely related, and adjusting one parameter usually affects other parameters. Therefore, it has been difficult for a single class of elastomeric materials to achieve a wide range of mechanical properties while maintaining the desired acoustic properties. Therefore, the field relies on a variety of different material formulations to meet the different acoustic transmission requirements of medical and non-destructive testing applications.

[0009] To overcome the limitations of the prior art methods for making acoustic transmission materials with a wide range of mechanical properties and a narrow range of acoustic properties, the present invention herein describes a method for producing a polyurethane gel formulation, which is based in part on a reaction mixture of an isocyanate (NCO) prepolymer, a selected polyol containing groups reactive to these isocyanate groups, and an organic plasticizer. By adjusting the composition of the reaction mixture according to the present invention, a polyurethane is produced, whose stiffness varies from approximately Shore A50 to less than Shore OOO 0 (i.e., the elastic modulus differs by 10X to 1000X), while the changes in the speed of sound, acoustic impedance, and acoustic attenuation of the material are less than 5%. In acoustic transmission applications including medical diagnostic imaging, the desired properties of the material are properties that match soft tissue in terms of speed and impedance, i.e., approximately 1540 m / s and 1.5 MRayls, respectively. In most cases, the desired attenuation is as low as possible, or at least lower than that of human soft tissue, or less than 1.0 dB / MHz-cm.

[0010] In addition, as described herein, the surface properties of the materials of the present invention can also be controlled to range from no surface tackiness to very high surface tackiness, which may be required for each unique application where an acoustic transmission material is used. The materials described herein can also be adhered to other materials (including silicone rubber, polyurethane rubber, metal, and semi-rigid plastics), thus providing a way to integrate the materials into multi-layer acoustic coupling assemblies, which may be required for each unique application. Various embodiments of the present invention are described herein. Summary of the Invention

[0011] The exemplary embodiments described herein have innovative features, where any single feature is not indispensable and is not solely responsible for its desired properties. The following description and the drawings elaborate certain illustrative embodiments of the present disclosure, which indicate several exemplary ways in which the various principles of the present disclosure can be implemented. However, these illustrative examples are not exhaustive of the many possible embodiments of the present disclosure. Without limiting the scope of the claims, some advantageous features will now be summarized. When considered in conjunction with the drawings, other objects, advantages, and novel features of the present disclosure will be set forth in the following detailed description of the present disclosure, which is intended to illustrate and not limit the invention.

[0012] The present invention overcomes the limitations of existing elastomeric acoustic transmission materials. In an embodiment, the present invention provides a method for formulating a polyurethane-based acoustic transmission material having a wide range of mechanical properties and a narrow range of acoustic properties, which are customized for acoustic transmission in medical, non-destructive testing, sonar, and other acoustic applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The drawings illustrate certain aspects of some embodiments of the present invention and should not be used to limit or define the present invention. These drawings, in conjunction with the written description, are used to explain certain principles of the present invention. To more fully understand the nature and advantages of the present technology, please refer to the following detailed description of the preferred embodiments in conjunction with the drawings, wherein: Figure 1 FIG. is a schematic diagram of an exemplary acoustic transmission pad for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention.

[0014] Figure 2 Depicted is a multi-component acoustic transmission device for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention, wherein one of the components is an acoustic couplant that aids in transmitting ultrasonic energy through the acoustic transmission pad into the receiving body in a medical application.

[0015] Figure 3 Depicted is a multi-component acoustic transmission device for transmitting ultrasonic energy into a receiving body in a medical application according to an embodiment of the present invention, wherein one of the components is an acoustic couplant that aids in transmitting ultrasonic energy through the acoustic transmission pad into the receiving body in a medical application, and one of the components is an acoustic transmission protective layer.

[0016] Figure 4Depicts a multi-component acoustic transmission device for transmitting ultrasonic energy into a receiving body in a medical application, wherein one of the components is an acoustic coupling agent that aids in transmitting ultrasonic energy through an acoustic transmission pad into the receiving body in a medical application, and one of the components is an acoustic transmission type protective layer encapsulating the acoustic transmission pad.

[0017] Figure 5 Depicts a multi-component acoustic transmission device for transmitting ultrasonic energy into a receiving body in a non-destructive testing application. Detailed Description

[0018] Reference will now be made in detail to various exemplary embodiments of the present invention. It should be understood that the following discussion of the exemplary embodiments is not intended to limit the present invention. On the contrary, the following discussion is provided to enable the reader to understand certain aspects and features of the present invention in more detail.

[0019] The present invention relates to formulations of polymeric acoustic transmission materials based on reaction mixtures of isocyanate (NCO) prepolymers, polyols having OH functional groups reactive with NCO groups, and organic plasticizers and fillers. The present invention describes processes for producing these acoustic transmission materials and acoustic coupling devices / articles including these acoustic transmission materials.

[0020] The physical, acoustic, and mechanical properties of polyurethanes can be modified by changing the composition of the reaction mixture and the reaction conditions. Polyurethanes can be tailored to be rigid or flexible since the polymer structure consists of soft segments and hard segments. The soft segments are formed from high molecular weight polyols, which affect the flexibility and elastic properties of the polyurethane, while the hard segments are formed from isocyanates and crosslinking agents, which affect rigidity and durability. Generally, reducing the NCO:OH molar ratio in the cured polymer reduces crosslinking within the polymer network and increases the elasticity, flexibility, and softness of the polyurethane. However, when forming soft polyurethane gels, the NCO:OH molar ratio must be high enough to form a crosslinked polymer network while also being low enough to produce unreacted polyol chains, thereby producing a gel-like relaxation behavior. Depending on the specific formulation, the lower limit of the NCO:OH molar ratio is about 0.1, which produces a soft, liquid-like gel with a hardness on the Shore OOO scale.

[0021] In addition to reducing the NCO:OH ratio, the physical properties of polyurethanes can also be adjusted by adding organic plasticizers. Internal plasticizers are flexible monomers directly incorporated into 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 forming specific compound properties, but they are known to migrate and leach out of the material over time. According to the present invention, the use of plasticizers enables the achievement of softer and more flexible polyurethanes than those achievable at a specific NCO:OH ratio. In an embodiment, the polyurethane gel can consist of a very high proportion of plasticizer, with particularly soft gels containing more than 50% by mass of plasticizer.

[0022] Suitable isocyanates for preparing the prepolymer reaction mixture are preferably aliphatic polyisocyanates, cycloaliphatic polyisocyanates or aromatic polyisocyanates with an NCO functionality between 2 and 5, preferably between 2.5 and 4. Aliphatic isocyanates are preferred when optical transparency and weather resistance are required, as they produce polymers with high UV resistance, improved durability and toughness compared to aromatic polyisocyanates. Examples of suitable polyisocyanates include, but are not limited to, the following: diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI) and optionally modified polymer compositions or combinations of the above, including biuret and trimer.

[0023] Polyols suitable for reaction with isocyanates include polyols having a functionality of 1 to 6 and a molecular weight between 1000 and 20000. A variety of polyether or polyester polyols can be used to form polyurethanes, but polyether or polyester polyols with a functionality close to 2, a molecular weight between 1000 and 5000, a linear polyether backbone structure, and an optionally vinyl content between 5% and 60% are preferred to achieve a soft polyurethane gel. Higher vinyl content imparts greater flexibility to the chain and better compatibility with other polyols (especially polypropylene glycol (PPG) and polytetramethylene ether glycol (PTMEG)). This improved compatibility provides opportunities for blending polyols and manufacturing blended prepolymers. Examples of suitable polyols include, but are not limited to, the following: polyhydroxyl-polyether, polyhydroxyl-polyester, polyhydroxyl-polyacetal, polyhydroxyl-polyesteramide, polyhydroxyl-polyamide, polyhydroxyl-polybutadiene, and mixtures thereof.

[0024] External plasticizers are preferably incorporated into the sound transmissive material as they do not significantly disrupt the integrity of the polymer network. External plasticizers suitable for incorporation into the sound transmissive material include external plasticizers having a long-chain linear aliphatic backbone which facilitate their retention within the hydrophobic polymer network while also imparting high flexibility to the polyurethane elastomer. Examples of suitable plasticizers include, but are not limited to, the following: 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). Optionally, phenyl, biphenyl, terphenyl, toluene, xylene, and other alkylbenzenes can be incorporated to provide external plasticizers with high fluidity within the elastomer, thereby imparting additional flexibility to the elastomer and the ability to self-heal after tearing or damage.

[0025] The NCO:OH molar ratio for manufacturing the sound transmissive material can range from 0.1 to 4, but is preferably between 0.5 and 2. In the absence of plasticizers, a low NCO:OH molar ratio (i.e., <1.0) results in a weakly crosslinked polyurethane gel that cannot maintain its shape and exhibits high surface tackiness. A higher NCO:OH ratio (i.e., >1.0) is preferably used to produce a fully crosslinked polymer network and the use of internal plasticizers and / or external plasticizers is utilized to achieve the desired physical, mechanical, and acoustic properties.

[0026] Polyurethanes can be formulated using a one-shot process or a prepolymer process. For example, in the one-shot process, all components are added simultaneously to the reaction mixture and mixed with each other. For example, in the prepolymer process, all of the isocyanate is first reacted with a portion of the polyol to form a liquid prepolymer having a reduced free isocyanate content of from 1 wt% to 15 wt%, which liquid prepolymer is then reacted with the remaining polyol, plasticizer, and catalyst to produce an elastomer. Benefits of using the prepolymer process include reduced reaction exotherm and improved processability of the isocyanate to improve mixing during secondary reactions. In the context of formulating an acoustic coupling material, either of these two processes can be used.

[0027] An acoustic transmission material can be integrated into an acoustic transmission device and is suitable for medical, non-destructive testing, sonar, or other acoustic transmission applications. In an embodiment, the acoustic transmission material can be cured in a physical mold and then demolded to impart the shape required for the final application.

[0028] In an embodiment, Figure 1 A polyurethane acoustic transmission material 100 is depicted, which is acoustically coupled to an ultrasonic transducer 102 and a receiver 104, which receiver 104 has internal features 106 that are the object of acoustic interrogation. The polyurethane acoustic transmission material 100 can be formulated to have surface tackiness that provides acoustic coupling between the ultrasonic transducer 102, the polyurethane acoustic transmission material 100, and the receiver 104, which can include patient anatomy or a non-destructive testing sample.

[0029] In Figure 2 the depicted embodiment, an acoustic coupling material 200 is applied to the surface of the polyurethane acoustic transmission material 100 to provide acoustic coupling between the ultrasonic transducer 102, the polyurethane acoustic transmission material 100, and the receiver 104. The acoustic coupling material 200 can include an aqueous mobile phase or a non-aqueous mobile phase and preferably includes water, an acoustic coupling gel, a hydrogel, an aqueous lubricant, a synthetic lubricant, a mineral oil, or a petroleum-based lubricant. The acoustic coupling material 200 can include an adhesive that temporarily or permanently attaches the polyurethane acoustic transmission material 100 to the ultrasonic transducer 102 and / or the receiver 104.

[0030] In Figure 3In the preferred embodiment depicted, the acoustic transmission material 100 can be directly integrated into a multi-component device. An example embodiment is a medical ultrasound device having a biocompatible outer surface material 300 and an internal space filled with a polyurethane-based acoustic transmission material 100. The biocompatible surface can include polyurethane, cured silicone, or a plastic selected from polymethylpentene, cross-linked polystyrene, and divinylbenzene, polypropylene, polyether block amide, polyester, polyethylene, polyethylene terephthalate, nylon, and polyimide, or one or more of these. The acoustic transmission material 100 can be cured between the ultrasonic transducer 102 and the biocompatible surface 300, thereby providing a path for transmitting ultrasonic energy from the ultrasonic transducer 102 to the biocompatible surface 300 and ultimately to the patient's body 104.

[0031] In Figure 4 In the embodiment depicted, the acoustic transmission material 100 can be directly integrated into a multi-component device, where the biocompatible outer surface material 400 encapsulates the entire polyurethane-based acoustic transmission material 100. The biocompatible surface can include polyurethane, cured silicone, or a plastic selected from polymethylpentene, cross-linked polystyrene, and divinylbenzene, polypropylene, polyether block amide, polyester, polyethylene, polyethylene terephthalate, nylon, and polyimide, or one or more of these. The acoustic coupling material 200 can be applied to the surface of the biocompatible outer surface 400 to provide acoustic coupling between the ultrasonic transducer 102, the multi-component device including the polyurethane acoustic transmission material 100 and the biocompatible outer surface 400, and the recipient 104. The acoustic coupling material 200 can include an aqueous mobile phase or a non-aqueous mobile phase, preferably including water, an acoustic coupling gel, a hydrogel, an aqueous lubricant, a synthetic lubricant, a mineral oil, or a petroleum-based lubricant. The acoustic coupling material 200 can include an adhesive material that temporarily or permanently attaches the biocompatible outer surface 400 to the ultrasonic transducer 102 and / or the recipient 104.

[0032] In Figure 5In the depicted embodiment, the non-destructive testing coupling device has an outer surface coating 300 and an internal space. The outer surface coating 300 is robust against harsh chemical exposure, and the internal space is filled with an acoustic transmission material 100. In this embodiment, the acoustic transmission material 100 serves as a delay line between the non-destructive testing acoustic transducer 302 and the device undergoing non-destructive testing 304. The acoustic transmission material 100 can be joined to the device 304 undergoing non-destructive testing by temporarily or permanently attaching the acoustic transmission material 100 to the device 304 undergoing non-destructive testing with one or more adhesive materials. The acoustic transmission material 100 can be joined to the device 304 undergoing non-destructive testing by a mechanical joining mechanism (e.g., including clamps and fasteners). The acoustic transmission material 100 can be joined to the device 304 undergoing non-destructive testing by attaching a mechanical joining mechanism between the outer surface coating 300 and the device 304 undergoing non-destructive testing.

[0033] In embodiments of these multi-component devices, the polyurethane acoustic transmission material can cure within voids in the device and cannot be removed. Polyurethane can exhibit adhesion to the surfaces of other materials in the device, and as is known to those of ordinary skill in the art, adhesion can be improved by using a primer (e.g., including one or more silane-based primers), the properties of which are selected based on the materials involved.

[0034] The acoustic transmission material can optionally incorporate additives to impart additional desired properties. In an exemplary embodiment, the acoustic transmission material formulation can include a trace amount of a colorant (such as titanium dioxide) to change the color of the material. In a separate embodiment, the acoustic transmission material formulation can include particulate fillers (such as silica particulates) to change the acoustic scattering properties of the material.

[0035] Example A polyurethane-based acoustic transmission material is produced by a one-shot process using the following isocyanates and mixed polyols. The physical, acoustic, and mechanical properties are shown in Table 1.

[0036] Polyurethane #1: A polymeric hexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N 3300, commercially available) and a mixture of hydroxyl terminated polybutadiene (Krasol LBH2000, commercially available from Cray Valley TM ) and polypropylene glycol (Arcol PPG 2000, commercially available from Covestro TMThe mixed polyols (composed of []) react at an NCO:OH ratio of 1.6. The hydroxyl functionality of the prepared mixture is 2, the viscosity is 450 cps, and the density is approximately 0.95 g / ml. Dibutyltin dilaurate (DBTDL) is used as a catalyst, 20% w / w of Palatinol 111P (DUP) is added, and the mixture is cured at 80 °C for two hours.

[0037] Polyurethane #2: The polymeric hexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available) reacts with the mixed polyols composed of hydroxyl-terminated polybutadiene (Krasol LBH2000, commercially available from Cray Valley TM and polypropylene glycol (Arcol PPG 2000, commercially available from Covestro TM at an NCO:OH ratio of 1.2. The hydroxyl functionality of the prepared mixture is 2, the viscosity is 450 cps, and the density is approximately 0.95 g / ml. Dibutyltin dilaurate (DBTDL) is used as a catalyst, 20% w / w of Palatinol 111P (DUP) is added, and the mixture is cured at 80 °C for two hours.

[0038] Polyurethane #3: The polymeric hexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available) reacts with the mixed polyols composed of hydroxyl-terminated polybutadiene (Krasol LBH2000, commercially available from Cray Valley TM and polypropylene glycol (Arcol PPG 2000, commercially available from Covestro TM at an NCO:OH ratio of 1.2. The hydroxyl functionality of the prepared mixture is 2, the viscosity is 450 cps, and the density is approximately 0.95 g / ml. Dibutyltin dilaurate (DBTDL) is used as a catalyst, 20% w / w of Palatinol 111P (DUP, commercially available from BASF TM is added, 5% w / w of Paratherm HT is added, and the mixture is cured at 80 °C for two hours.

[0039] Polyurethane #4: The polymeric hexamethylene diisocyanate trimer with an NCO content of 21.8% (Desmodur N3300, commercially available) reacts with the mixed polyols composed of hydroxyl-terminated polybutadiene (Krasol LBH2000, commercially available from Cray Valley TM)(Arcol PPG 2000, commercially available from Covestro) and polypropylene glycol react at an NCO:OH ratio of 1.0. The hydroxyl functionality of the configured mixture is 2, the viscosity is 450 cps, and the density is approximately 0.95 g / ml. Dibutyltin dilaurate (DBTDL) is used as a catalyst, 20% w / w of diundecyl phthalate (DUP, Palatinol 111P, commercially available from BASF TM ) is added, 10% w / w of terphenyl (Paratherm HT) is added, and the mixture is cured at 80 °C for two hours. TM

[0040] Table 1: Physical and acoustic properties of exemplary sound transmission materials polyurethane #1 to polyurethane #4.

[0041]

[0042] Polyurethane #5: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1, 3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TM ) at an NCO:OH ratio of 1.66. 12.73% w / w of additional 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added, and the mixture is cured at 75 °C for one hour.

[0043] Polyurethane #6: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1, 3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TM ) at an NCO:OH ratio of 1.66. 21.31% w / w of additional 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added, and the mixture is cured at 75 °C for one hour.

[0044] Polyurethane #7: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TM ) at an NCO:OH ratio of 1.66. An additional 29.41% w / w of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added, and the mixture is cured at 75 °C for one hour.

[0045] Polyurethane #8: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TM ) at an NCO:OH ratio of 1.66. An additional 36.00% w / w of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added, and the mixture is cured at 75 °C for one hour.

[0046] Polyurethane #9: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TM ) at an NCO:OH ratio of 1.66. An additional 45.45% w / w of 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added, and the mixture is cured at 75 °C for one hour.

[0047] Polyurethane #10: A hexamethylene diisocyanate oligomer, an isocyanurate with an NCO content of 21.89% (Tolonate HDT, commercially available), reacts with a mixed polyol composed of poly(tetramethylene ether) glycol, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, dibutyltin dilaurate, and an antifoaming agent (GNX-271RVN13, commercially available from Tandem Products, Inc. TMThe mixed polyols, consisting of [...], react at an NCO:OH ratio of 1.66. 48.94% w / w of additional 2,2,4-trimethyl-1,3-pentanediol diisobutyrate is added and the mixture is cured at 75 °C for one hour.

[0048] Table 2: Physical and acoustic properties of exemplary sound transmission materials polyurethane #5 to polyurethane #7.

[0049]

[0050] Table 3: Physical and acoustic properties of exemplary sound transmission materials polyurethane #8 to polyurethane #10.

[0051]

[0052] Embodiments of the present invention also include a computer-readable medium that includes one or more computer files, the one or more computer files including a set of computer-executable instructions for performing one or more of the calculations, steps, processes, and operations described and / or depicted herein. In an exemplary embodiment, the files may be stored on the computer-readable medium continuously or discontinuously. Embodiments may include a computer program product that includes a computer file, or is in the form of a computer-readable medium that includes a computer file, and is optionally provided to a consumer by packaging, or alternatively provided to a consumer by electronic distribution. As used in the context of this specification, "computer-readable medium" is 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 electrically erasable programmable read-only memory (EEPROM), and a RAM. In an exemplary embodiment, the computer-readable medium has a set of instructions stored thereon that, when executed by a processor, cause the processor to perform tasks based on data stored in the electronic database or memory described herein. The processor may implement the process through any program discussed in this disclosure or through any equivalent program.

[0053] In other embodiments of the present invention, files including a set of computer-executable instructions may be stored in a computer-readable memory on a single computer or distributed across multiple computers. Those skilled in the art will further understand from this disclosure that, in addition to software, hardware or firmware may be used to implement the present invention. Thus, as used herein, the operations of the present invention can be implemented in a system including a combination of software, hardware, or firmware.

[0054] Embodiments of the present disclosure include one or more computers or devices loaded with the set of computer-executable instructions described herein. The computer or device can be a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus for manufacturing a specific machine, such that the 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. The computer or device that executes the specified calculations, processes, steps, operations, algorithms, statistical methods, formulas, or computational routines of the present disclosure can include at least one processing element, such as a central processing unit (i.e., a processor), and a computer-readable memory that can include random access memory (RAM) or read-only memory (ROM). The computer-executable instructions can be embedded in the computer hardware or stored in the computer-readable memory such that the computer or device can be directed to perform one or more of the calculations, steps, processes, and operations depicted and / or described herein.

[0055] Additional embodiments of the present disclosure include a computer system for performing the computer-implemented methods of the present disclosure. The computer system can 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 method. The computer system can include a stand-alone computer such as a desktop computer, a portable computer such as a tablet computer, laptop computer, PDA, or smartphone, or a group of computers connected via a network, including client-server configurations and one or more database servers. The network can use any suitable network protocol, including IP, UDP, or ICMP, and can be any suitable wired or wireless network, including any local area network, wide area network, the Internet, a telecommunications network, a Wi-Fi-enabled network, or a Bluetooth-enabled network. In one embodiment, the computer system includes a central computer connected to the Internet, the central computer having computer-executable instructions stored in a memory that is operably connected to an internal electronic database. The central computer can perform the computer-implemented method based on inputs and commands received from remote computers via the Internet. The central computer can effectively serve as a server, and the remote computers can serve as client computers, thereby establishing a server-client relationship, and the client computers issue queries or receive outputs from the server via the network.

[0056] The input / output interface may include a graphical user interface (GUI) that can be used in conjunction with computer-executable code and an electronic database. The graphical user interface may allow a user to perform these tasks by using text fields, check boxes, drop-down menus, command buttons, etc. 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 via a computer connected to the Internet. In one embodiment, the user interface may be accessed by typing an Internet address via an industry-standard web browser and logging into a web page. The user interface can then be operated via a remote computer (client computer) accessing the web page, and queries can be sent or outputs received from the server via a network connection.

[0057] The present invention has been described with reference to specific embodiments having various features. Based on the disclosure provided above, those skilled in the art should understand that various modifications and variations can be made in the practice of the present invention without departing from the scope or spirit of the present invention. Those skilled in the art will recognize that the disclosed features can be used alone, in any combination, or omitted based on the requirements and specifications of a given application or design. When an embodiment mentions "comprising" certain features, it should be understood that the embodiment can alternatively "consist of any one or more of the features" or "consist essentially of any one or more of the features". Other embodiments of the present invention will be apparent to those skilled in the art by considering the specification and practice of the present invention.

[0058] It should be noted that where a range of values is provided in this specification, each value between the upper and lower limits of the range is also specifically disclosed. The upper and lower limits of these smaller ranges can also be independently included or excluded from the range. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" include plural referents. The specification and examples are intended to be exemplary, and variations that do not depart from the essence of the present invention fall within the scope of the present invention. Additionally, all references cited in this disclosure are hereby incorporated by reference in their entirety, and thus are intended to provide an effective way to supplement the enabling disclosure of the present invention and provide a background for detailed description of the ordinary skill level in the art.

[0059] As used herein, the term "about" means plus or minus five units (e.g., percentage) of the stated value.

[0060] The "some embodiments", "embodiments", "one embodiment", or "other embodiments" mentioned in the specification refer to the specific features, structures, or characteristics described in connection with the embodiments being included in at least some, but not necessarily all, embodiments of the present invention.

[0061] As used herein, the terms "substantially" and "essentially" refer to what would be readily recognized by one of ordinary skill in the art.

[0062] It should be understood that the language and terminology employed herein should not be construed as limiting, but rather for descriptive purposes only.

[0063] It should be understood that while some of the illustrations and figures may be near proper scale, most of the illustrations and figures are not intended to be to proper scale.

[0064] It should be understood that the details set forth herein do not constitute a limitation on the application of the present invention.

[0065] In addition, it should be understood that the present invention can be carried out or practiced in various ways and that the present invention can be implemented in embodiments other than those outlined in the foregoing description.

Claims

1. An acoustic coupling article for acoustic signal transmission, comprising an elastomeric material capable of conforming to the surface of one or more receivers, Among them, at least one acoustic signal transducer acoustically coupled to the elastomeric material to transmit acoustic energy generated by the at least one acoustic signal transducer through the elastomeric material into the receiver, wherein the elastomeric material comprises a mixture of two or more polymerizable materials, the proportions of the two or more polymerizable materials being used to adjust the Shore hardness between Shore A 50 and Shore OOO 0, and having an acoustic attenuation coefficient less than or equal to 3.0 dB / MHz-cm.

2. The acoustic coupling article according to claim 1, wherein, The proportions of the two or more polymerizable materials can be adjusted such that the longitudinal sound velocity of the acoustic coupling at 25 °C is between 1000 m / s and 1850 m / s.

3. The acoustic coupling article according to claim 1, wherein The proportions of the two or more polymerizable materials can be adjusted such that the acoustic impedance of the elastomeric material is between 1.0 MRayl and 3.0 MRayl.

4. The acoustic coupling article according to claim 1, wherein The density of the elastomeric material is between 0.5 g / cm 3 and 1.5 g / cm 3 .

5. The acoustic coupling article according to claim 1, wherein, At least one of the two or more polymerizable materials in the mixture of the two or more polymerizable materials is a polyurethane, and the polyurethane comprises: at least one of the following polyols: polyhydroxypolyether, polyhydroxypolyester, polyhydroxyacetal, polyhydroxypolyesteramide, polyhydroxypolyamide, polyhydroxypolybutadiene, and combinations or mixtures thereof; at least one of the following isocyanates or compositions comprising one or more isocyanates: diphenylmethane diisocyanate, hexamethylene diisocyanate, toluene diisocyanate, isophorone diisocyanate, optionally modified polymer compositions, and combinations or mixtures thereof; and optionally includes additives selected from one or more of the following: one or more colorants, one or more particulate fillers, and combinations or mixtures thereof.

6. The acoustic coupling article according to claim 5, further comprising one or more plasticizers, wherein, The one or more plasticizers are added to or combined with the polyurethane to adjust the Shore hardness, density, acoustic properties, and the ability to self-heal after tearing, and wherein the one or more plasticizers include at least one of the following: 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, dibutyl sebacate DBS, diisodecyl adipate DIDA, dibutoxyethyl adipate DBEA, dibutoxyethoxyethyl sebacate DBEES, trioctyl trimellitate TOTM, dioctyl terephthalate DOTP, phenyl, biphenyl, terphenyl, toluene, xylene, alkylbenzene, and combinations and mixtures thereof.

7. The acoustic coupling article according to claim 1, wherein, The elastomeric material can be molded into a three-dimensional shape, and wherein the molded elastomeric material substantially or largely retains the three-dimensional shape during use or handling.

8. The acoustic coupling article according to claim 1, wherein, The elastomeric material can retain its mechanical and acoustic properties for five years or longer.

9. The acoustic coupling article according to claim 1, wherein The elastomeric material does not degrade significantly due to dehydration and can retain its mechanical and acoustic properties for five years or longer without maintenance.

10. The acoustic coupling article according to claim 1, wherein, The surface of the one or more receivers is a surface or structural material that undergoes non-destructive testing.

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

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

13. The acoustic coupling article according to claim 1, wherein, Using a mechanical engagement mechanism or an adhesive material, the elastomeric material can be temporarily attached to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or attached to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

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

15. The acoustic coupling article according to claim 1, wherein, Using a coupling agent, the elastomeric material is acoustically coupled to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or acoustically coupled to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

16. The acoustic coupling article according to claim 15, wherein, The coupling agent is an aqueous coupling agent.

17. The acoustic coupling article according to claim 16, wherein, The aqueous coupling agent includes one or more of acoustic gel, water, saline solution, or hydrogel.

18. The acoustic coupling article according to claim 1, wherein, Using a non-aqueous coupling agent, the elastomeric material is acoustically coupled to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or acoustically coupled to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

19. The acoustic coupling article according to claim 18, wherein, The non-aqueous coupling agent includes one or more of synthetic lubricant, silicone-based lubricant, mineral oil, or petroleum-based lubricant.

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

21. The acoustic coupling article according to claim 1, wherein, The surface of the elastomeric material is bonded to at least one of silicone rubber, polyurethane rubber, or semi-rigid thermoplastic, and wherein at least one of the silicone rubber, polyurethane rubber, or semi-rigid thermoplastic is optionally applied with a silane-based surface primer on the surface of the elastomeric material, thereby forming a multi-layer acoustic coupling article.

22. The acoustic coupling article according to claim 21, wherein, Using a mechanical engagement mechanism or an adhesive material, the multi-layer acoustic coupling article can be temporarily attached to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or attached to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

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

24. The acoustic coupling article according to claim 21, wherein, Using an aqueous coupling agent, the multi-layer acoustic coupling article is acoustically coupled to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or acoustically coupled to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

25. The acoustic coupling article according to claim 21, wherein Using a non-aqueous coupling agent, the multi-layer acoustic coupling article is acoustically coupled to the surface of the one or more receivers, the surface of the at least one acoustic signal transducer, or acoustically coupled to the surface of the one or more receivers and the surface of the at least one acoustic signal transducer.

26. The acoustic coupling article according to claim 21, wherein, The surface of the one or more receivers is the surface of an anatomical region of the human body.

27. The acoustic coupling article according to claim 21, wherein, The surface of the one or more receivers is a surface or structural material undergoing non-destructive testing.

28. The acoustic coupling article according to claim 21, wherein, The elastomeric material and any other material combined therewith are optically transparent or optically translucent.

29. A composition for acoustic transmission signals, the composition comprising a selected proportion of a polymerizable material, wherein, The selection of the isocyanate prepolymer and polyol results in an NCO:OH molar ratio between 0.8 and 2.0, wherein the pre-mixed plasticizer %w / w is between 10% and 60%, wherein the selected ratio is used to adjust the Shore hardness below Shore A50, and wherein the selected ratio provides an acoustic attenuation coefficient of less than or equal to 3.0 dB / MHz-cm.

30. An elastomeric material comprising a mixture of two or more polymerizable materials, wherein, The ratio of the two or more polymerizable materials can be varied during the synthesis of the elastomeric material, and the change in the ratio of the two or more polymerizable materials results in a change in the viscosity or hardness of the elastomeric material, wherein the change in the viscosity or hardness of the elastomeric material does not cause an increase or decrease in the sound speed, acoustic impedance, and acoustic attenuation of the elastomeric material by five percent or more.

Images