3D printing ultrasonic phantom hydrogel material as well as preparation method and application thereof

Abstract

The invention provides a 3D printing ultrasonic phantom hydrogel material as well as a preparation method and application thereof, and relates to the field of medical materials. The hydrogel material for the 3D printing ultrasonic phantom comprises a waterborne polyurethane acrylate emulsion, a photocuring monomer, inorganic salt, a scatterer, a stabilizer, deionized water, a photoinitiator and a light absorber. Wherein the photocuring monomer comprises a water-based photocuring monomer and a sulfonic group-containing photocuring monomer in a mass ratio of 1: (0.3-0.7). The 3D printing ultrasonic phantom hydrogel material provided by the invention has good mechanical properties and anti-swelling properties, has acoustic characteristics such as sound velocity, sound attenuation coefficient and the like similar to those of human tissues, and meets the requirements of an ultrasonic phantom on ultrasonic characteristics.

Description

Technical Field

[0001] This invention relates to the field of medical materials, and in particular to a 3D-printed ultrasonic phantom hydrogel material, its preparation method, and its application. Background Technology

[0002] Ultrasound imaging technology has been widely applied in clinical medicine, such as obstetrics and gynecology, cardiology, and breast disease. Medical ultrasound imaging involves transmitting ultrasound waves into the human body, which are then acquired and processed to generate images of internal tissues. Ultrasound phantoms, or ultrasound-mimicking tissue materials, are typically used to train operators of ultrasound imaging systems. Furthermore, researchers often use ultrasound phantoms in conjunction with computer simulation technology to assist in the development of new ultrasound transducers and systems.

[0003] Hydrogel materials are the most commonly used materials for ultrasonic phantoms due to their high water content, mechanical properties, and acoustic properties, which are similar to those of living organisms. However, the large amount of water contained in hydrogels usually evaporates slowly over time, causing changes in various properties of the phantom and significantly affecting its stability. For long-term preservation, hydrogels can be immersed in water to prevent water loss, which requires good anti-swelling properties. However, hydrogels typically contain a large amount of hydrophilic polymers, resulting in poor anti-swelling properties.

[0004] Meanwhile, in ultrasound phantoms, the scatterer is crucial for ultrasound imaging, and the contrast in ultrasound images is generated by acoustic reflection. Acoustic reflection is caused by the difference in acoustic impedance between the matrix and the scatterer. Typically, the scatterer consists of particles a few micrometers or tens of micrometers in size, which have poor dispersion stability in hydrogels.

[0005] Furthermore, hydrogel materials are primarily formed using molds, making it impossible to create three-dimensional structures similar to human tissue. The development of 3D printing technology has provided new avenues for fabricating ultrasonic phantoms with biomimetic three-dimensional structures. Among these, photopolymerization 3D printing is one of the earliest developed and most precise printing technologies. The resins used in photopolymerization 3D printing of hydrogels are mainly aqueous solutions of monomers, oligomers, photoinitiators, and other additives. Oil-soluble photoinitiators typically cannot dissolve in aqueous solutions, and the common water-soluble photoinitiator Irgacure 2959 has very low initiation efficiency under the 405nm light commonly used in commercial printers, making photopolymerization printing impossible. Therefore, improving the solubility of oil-soluble photoinitiators in aqueous solutions is the biggest challenge restricting the development of photopolymerization 3D printing of hydrogels.

[0006] Therefore, while existing hydrogel ultrasonic phantom materials exhibit ultrasonic properties similar to those of the human body, their long-term stability is unsatisfactory due to the volatile nature of water in hydrogels. To achieve long-term preservation, hydrogels are typically immersed in water to prevent moisture loss, but hydrogels generally have poor resistance to swelling. Furthermore, the scatterers within the material are relatively large, resulting in poor dispersion stability. Additionally, oil-soluble photoinitiators commonly used in photopolymerization 3D printing are difficult to dissolve in aqueous solutions, leading to excessively low curing rates and hindering the realization of photopolymerization 3D printing using hydrogels. Summary of the Invention

[0007] In view of this, and in response to the problems of poor swelling resistance, poor scatterer stability, and inability to prepare three-dimensional structures similar to human tissue in existing technologies, this invention provides a 3D printed ultrasonic phantom hydrogel material, its preparation method, and its application, which at least solves some of the problems of existing technologies.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] On one hand, a 3D-printed ultrasonic phantom hydrogel material comprises the following parts by weight of raw materials:

[0010] The composition includes 5-20 parts of waterborne polyurethane acrylate emulsion, 6-30 parts of photocurable monomer, 1-10 parts of inorganic salt, 1-5 parts of scattering agent, 1-5 parts of stabilizer, 70-90 parts of deionized water, 0.1-5 parts of photoinitiator, and 0.001-0.5 parts of light absorber; among which,

[0011] The photocurable monomers include water-based photocurable monomers and sulfonic acid-containing photocurable monomers.

[0012] Preferably, the 3D printed ultrasonic phantom hydrogel material comprises the following raw materials in parts by weight: 8-14 parts of waterborne polyurethane acrylate emulsion, 11-13 parts of photocurable monomer, 3-5 parts of inorganic salt, 1-2 parts of scatterer, 1-3 parts of stabilizer, 70-72 parts of deionized water, 1-2 parts of photoinitiator, and 0.01-0.1 parts of light absorber.

[0013] Further, the photocurable monomer comprises an aqueous photocurable monomer and a sulfonic acid-containing photocurable monomer in a mass ratio of 1:(0.3-0.7); preferably, the photocurable monomer comprises an aqueous photocurable monomer and a sulfonic acid-containing photocurable monomer in a mass ratio of 1:(0.4-0.6).

[0014] Furthermore, the water-soluble curing monomer is selected from at least one of acrylamide, acrylomorpholine, hydroxyethyl acrylate, N-isopropylacrylamide, methacrylamide, and N-vinylpyrrolidone.

[0015] Furthermore, the sulfonic acid-containing photocurable monomer is selected from at least one of 2-acrylamido-2-methylpropanesulfonic acid, sodium p-styrenesulfonate, and sodium vinylsulfonate.

[0016] Furthermore, the inorganic salt is an inorganic salt containing calcium, iron, and zirconium ions.

[0017] Preferably, the inorganic salt is selected from at least one of calcium chloride, ferric chloride, and zirconium oxychloride.

[0018] Furthermore, the scatterer is selected from at least one of silicon dioxide, hydroxyapatite, and calcium phosphate.

[0019] Furthermore, the stabilizer is selected from at least one of polyvinyl alcohol, hyaluronic acid, waterborne polyurethane, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, and sodium stearate.

[0020] Furthermore, the photoinitiator is selected from at least one of (2,4,6-trimethylbenzoyl)diphenylphosphine oxide, azodimethyl-2-hydroxybutylpropionamide, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, ethyl (2,4,6-trimethylbenzoyl)phosphonate, benzophenone, isopropylthioxanthanone, 2,4-dimethylthioxanthanone, and lithium (2,4,6-trimethylbenzoyl)phosphate.

[0021] Furthermore, the light absorber is selected from at least one of the following: UV-327, Sudan I, UV-P, and Rhodamine B.

[0022] Furthermore, the waterborne polyurethane acrylate emulsion is obtained by reacting diisocyanate with hydroxyl-terminated polyols and diols with hydrophilic groups to obtain an isocyanate-terminated prepolymer, which is then reacted with hydroxyl-containing acrylates or acrylates to obtain a polyurethane acrylate resin, which is then emulsified.

[0023] Furthermore, the particle size of the aqueous polyurethane acrylate emulsion is 20-200 nm, preferably 20-60 nm.

[0024] Furthermore, in the waterborne polyurethane acrylate emulsion, the molar ratio of the diisocyanate, the hydroxyl-terminated polyol, the water-based diol, and the hydroxyl-containing acrylate is 1:(0.3-0.6):(0.3-0.6):(0.4-0.8).

[0025] Furthermore, in the aqueous polyurethane acrylate emulsion, the diisocyanate is selected from at least one of toluene diisocyanate, hydrogenated phenylmethane diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, and phenylmethane diisocyanate.

[0026] Furthermore, in the waterborne polyurethane acrylate emulsion, the number average molecular weight of the hydroxyl-terminated polyol is 1000-10000 g / mol; the hydroxyl-terminated polyol is selected from at least one of polyether polyol, polyester polyol, and polyolefin polyol.

[0027] Preferably, the polyether polyol is selected from at least one of polyethylene glycol, polypropylene glycol, and polytetrahydrofuran glycol; the polyester polyol is selected from at least one of polycaprolactone diol, polylactic acid diol, polyethylene adipate diol, and polybutylene adipate diol; and the polyolefin polyol is polybutadiene diol.

[0028] Furthermore, in the waterborne polyurethane acrylate emulsion, the diol with the hydrophilic group is one of 2,2-dimethylolpropionic acid, N-methyldiethanolamine, polyethylene glycol, and polyethylene glycol-polypropylene glycol copolymer.

[0029] Furthermore, in the waterborne polyurethane acrylate emulsion, the hydroxyl-containing (meth)acrylate is selected from at least one of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl methacrylate, and hydroxypropyl methacrylate.

[0030] In some specific embodiments, the aqueous polyurethane acrylate emulsion is prepared by the following method:

[0031] S1: Diisocyanate is reacted with hydroxyl-terminated polyol and diol with hydrophilic groups in a stepwise addition polymerization reaction under the action of a catalyst to obtain isocyanate-terminated polyurethane resin.

[0032] S2: React the isocyanate-terminated polyurethane resin obtained in step S1 with hydroxyl-containing (meth)acrylate, add a polymerization inhibitor, and obtain waterborne polyurethane acrylate.

[0033] S3: Add a neutralizing agent to the waterborne polyurethane acrylate obtained in step S2, and then add deionized water under vigorous stirring to obtain a waterborne polyurethane acrylate emulsion with a solid content of 10-30%.

[0034] Preferably, in step S1, the catalyst is a tertiary amine and / or organometallic catalyst; the amount of catalyst used is 200-600 ppm of the total mass of the raw materials.

[0035] Preferably, the catalyst comprises, but is not limited to, at least one of triethylenediamine, bis(dimethylaminoethyl) ether, stannous octoate, and n-butyltin laurate.

[0036] Preferably, in step S1, the reaction temperature of the polycondensation reaction is 50-100°C, and the reaction time is 1-12 hours.

[0037] Preferably, in step S2, the polymerization inhibitor is hydroquinone and / or p-methoxyphenol.

[0038] Preferably, in step S2, the amount of the polymerization inhibitor is 50 to 1000 ppm of the total mass of the raw materials.

[0039] Preferably, in step S2, the reaction temperature is 50–100°C and the reaction time is 1–12 h.

[0040] Preferably, in step S3, the stirring rate of the vigorous stirring is 400 to 3000 r / min.

[0041] Preferably, in step S3, when the diol with the hydrophilic group is 2,2-dimethylolpropionic acid, the neutralizing agent is selected from at least one of triethylamine, ammonia, and urea; when the diol with the hydrophilic group is N-methyldiethanolamine, the neutralizing agent is selected from at least one of formic acid, acetic acid, and hydrochloric acid; when the diol with the hydrophilic group is polyethylene glycol or polyethylene glycol-polypropylene glycol copolymer, no neutralizing agent is required.

[0042] On the other hand, the preparation method of the above-mentioned 3D printed ultrasonic phantom hydrogel material includes the following steps:

[0043] (1) Mix all raw materials and stir at low speed under light-protected conditions to obtain photosensitive resin;

[0044] (2) The photosensitive resin is printed by using photopolymerization 3D printing.

[0045] Furthermore, in step (1), the speed of the low-speed stirring is 200-400 r / min, and the stirring time is 2-4 h.

[0046] Further, in step (2), the photopolymerization 3D printing method is selected from any one of photopolymerization stereolithography, digital light processing photopolymerization 3D printing (DLP), and continuous liquid interface printing (CLIP).

[0047] Furthermore, in step (2), after the printing is completed, the obtained sample is also cleaned and then cured.

[0048] Preferably, ethanol or isopropanol is used to clean the sample during the cleaning process. The specific steps are as follows: put the sample into ethanol or isopropanol and ultrasonically clean it for 10 to 15 minutes.

[0049] Preferably, the post-curing process involves placing the sample in an ultraviolet box and curing it with ultraviolet light for 10–30 minutes.

[0050] On another note, the aforementioned 3D-printed ultrasonic phantom hydrogel material is used as an ultrasonic phantom in ultrasonic medicine.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. The 3D printed ultrasonic phantom hydrogel material provided by the present invention has acoustic properties such as sound velocity and sound attenuation coefficient similar to human tissue, which meets the requirements of ultrasonic phantom for ultrasonic properties.

[0053] 2. This invention prepares photosensitive resin by preparing microemulsion. Due to the water-oil dual-phase coexistence characteristic of the emulsion, oil-soluble photoinitiators can be directly used, which solves the problem of low solubility of current high-efficiency oil-soluble photoinitiators in water-based hydrogel resins, and realizes the photocuring 3D printing preparation of hydrogel materials.

[0054] 3. The ultrasonic phantom hydrogel of this invention incorporates two photocurable monomers. These monomers work synergistically, enabling the ultrasonic phantom hydrogel to form ionic coordination bonds with calcium, zirconium, and iron ions within its polymer network structure. This significantly improves the hydrogel's mechanical properties and achieves excellent anti-swelling characteristics. During storage, the hydrogel can be immersed in water to prevent changes in its acoustic and mechanical properties due to moisture loss.

[0055] 4. Compared with macromolecular scatterers such as cellulose, the inorganic particle scatterer proposed in this invention has higher ultrasound imaging contrast and is easier to disperse into the resin matrix. By using ionic or non-ionic water-soluble polymers, the dispersion stability of inorganic particles can be improved through electrostatic repulsion or steric hindrance, thereby enhancing the imaging stability of the ultrasound phantom. Attached Figure Description

[0056] Figure 1 This is the NMR spectrum of the waterborne polyurethane acrylate prepared in Example 2 of this invention;

[0057] Figure 2 This refers to the particle size of the aqueous polyurethane emulsion prepared in Example 2 of this invention;

[0058] Figure 3 This is the hydrogel model produced by digital light processing (DLP) 3D printing in Embodiment 2 of the present invention;

[0059] Figure 4 This is the tensile curve of the hydrogel material prepared by photopolymerization 3D printing in Example 2 of this invention;

[0060] Figure 5 This refers to the change in mass of the hydrogel-type ultrasonic phantom material in Example 2 when it is immersed in water over time. Detailed Implementation

[0061] The following non-limiting embodiments are intended to enable those skilled in the art to gain a more comprehensive understanding of the present invention, but do not limit the invention in any way. The following description is merely an exemplary illustration of the scope of protection of the present invention, and those skilled in the art can make various changes and modifications to the invention based on the disclosed content, which should also fall within the scope of protection of the present invention.

[0062] The present invention will be further described below by way of specific embodiments. Unless otherwise specified, all chemical reagents used in the embodiments of the present invention are obtained through conventional commercial means.

[0063] Example 1

[0064] This embodiment first provides an aqueous polyurethane methacrylate emulsion, the preparation method of which is as follows:

[0065] S1. Polyethylene glycol (40.0g, 0.02mol), polytetrahydrofuran glycol (40.0g, 0.02mol), 2,2-dimethylolpropionic acid (5.36g, 0.04mol), and 0.06g butyltin laurate catalyst were added to isophorone diisocyanate (22.2g, 0.1mol). The reaction system temperature was maintained at 80℃, and the reaction was monitored by infrared spectroscopy until the absorption peak of isocyanate no longer decreased, thus obtaining isocyanate-terminated polyurethane resin.

[0066] S2. React isocyanate-terminated polyurethane resin with hydroxyethyl acrylate (4.64 g, 0.04 mol), add 0.01 g of polymerization inhibitor hydroquinone, react at 60 °C until the characteristic absorption peak of the isocyanate group in the infrared spectrum completely disappears, and obtain waterborne polyurethane acrylate.

[0067] S3. Cool the system to room temperature, add triethylamine to neutralize the carboxyl groups in the molecular chain, and add 270.9 g of deionized water dropwise under high-speed stirring (600 r / min) to obtain an aqueous polyurethane acrylate emulsion with a solid content of 30% (the average particle size of the dynamic light scattering test is 58 nm).

[0068] This embodiment also provides a method for preparing a 3D-printed ultrasonic phantom hydrogel material, including the following steps:

[0069] (1) Preparation of photosensitive resin:

[0070] The raw materials are weighed according to the formula ratio. The specific raw material components of the 3D printed ultrasonic phantom hydrogel material are as follows, by weight:

[0071]

[0072]

[0073] Mix all raw materials and stir at low speed under light-protected conditions. The stirring speed is 400 r / min and the stirring time is 2 h to obtain photosensitive resin.

[0074] (2) The prepared photosensitive resin was poured into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set as needed, resulting in a smooth and highly detailed model surface. After printing, the support of the sample blank was removed, and it was ultrasonically treated in ethanol for 10 minutes, followed by curing in a UV oven for 25 minutes to obtain the final 3D printed hydrogel ultrasonic phantom. The test results showed that the sound velocity of the hydrogel was 1508±9 m / s, the sound attenuation coefficient was 0.57±0.03 dB / cm·MHz, and the density was 1.07 kg / m³. 3 .

[0075] Example 2

[0076] This embodiment first provides an aqueous polyurethane methacrylate emulsion, the preparation method of which is as follows:

[0077] S1. Add polyethylene glycol (60.0 g, 0.03 mol) and polyethylene glycol-polypropylene glycol copolymer (PPG-PPG) to hexamethylene diisocyanate (16.8 g, 0.1 mol). L-121 (176.0 g, 0.04 mol) and 0.02 g of butyltin laurate catalyst were used to react the product at 90 °C until the characteristic absorption peak of isocyanate in the infrared spectrum no longer decreased, thus obtaining an isocyanate-terminated polyurethane resin. Its 1H NMR spectrum is shown below. Figure 1 As shown (solvent is deuterated chloroform);

[0078] S2. React isocyanate-terminated polyurethane resin with hydroxyethyl acrylate (6.96g, 0.06mol), add 0.05g of polymerization inhibitor hydroquinone, and react at 55℃ until the reaction is complete and the characteristic absorption peak of the isocyanate group in the infrared spectrum completely disappears to obtain waterborne polyurethane acrylate.

[0079] S3: The system temperature was lowered to room temperature, and 261.8 g of deionized water was added dropwise under high-speed stirring (800 r / min). The organic solvent was removed by vacuum distillation to obtain a waterborne polyurethane acrylate emulsion with a solid content of 30% (average particle size of 45 nm according to dynamic light scattering test). The particle size is as follows: Figure 2 As shown.

[0080] This embodiment also provides a method for preparing a 3D-printed ultrasonic phantom hydrogel material, including the following steps:

[0081] (1) Preparation of photosensitive resin:

[0082] The raw materials are weighed according to the formula ratio. The specific raw material components of the 3D printed ultrasonic phantom hydrogel material are as follows, by weight:

[0083]

[0084] Mix all raw materials and stir at low speed under light-protected conditions. The stirring speed is 400 r / min and the stirring time is 2 h to obtain photosensitive resin.

[0085] (2) The prepared photosensitive resin is poured into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer are set as needed, resulting in a smooth and highly detailed model surface. After printing, the support of the sample blank is removed, and it is ultrasonically immersed in ethanol for 10 minutes, followed by curing in a UV oven for 15 minutes to finally obtain a 3D printed hydrogel ultrasonic phantom, such as... Figure 3 As shown in the figure. Tests revealed that the hydrogel has a sound velocity of 1520±9 m / s, a sound attenuation coefficient of 0.66±0.03 dB / cm·MHz, and a density of 1.09 kg / m³. 3 .

[0086] Example 3

[0087] This embodiment first provides an aqueous polyurethane methacrylate emulsion, the preparation method of which is as follows:

[0088] S1. Polytetrahydrofuran glycol (50.0 g, 0.05 mol) and polyethylene glycol-polypropylene glycol copolymer ( ) were added to isophorone diisocyanate (22.2 g, 0.1 mol). L-65 (105.0g, 0.03mol) and 0.04g of butyltin lauryl acid catalyst were added. The reaction system temperature was kept at 90℃ and the reaction was continued until the characteristic absorption peak of isocyanate in the infrared spectrum no longer decreased, thus obtaining isocyanate-terminated polyurethane resin.

[0089] S2. React isocyanate-terminated polyurethane resin with hydroxyethyl acrylate (6.96g, 0.04mol), add 0.05g of polymerization inhibitor hydroquinone, and react at 50℃ until the reaction is complete and the characteristic absorption peak of the isocyanate group in the infrared spectrum completely disappears to obtain waterborne polyurethane acrylate.

[0090] S3. Cool the system temperature to room temperature, add 390g of deionized water dropwise while stirring at high speed (800r / min), remove the organic solvent by vacuum distillation, and obtain a waterborne polyurethane acrylate emulsion with a solid content of 30% (average particle size of 68nm according to dynamic light scattering test).

[0091] This embodiment also provides a method for preparing a 3D-printed ultrasonic phantom hydrogel material, including the following steps:

[0092] (1) Preparation of photosensitive resin:

[0093] The raw materials are weighed according to the formula ratio. The specific raw material components of the 3D printed ultrasonic phantom hydrogel material are as follows, by weight:

[0094]

[0095] Mix all raw materials and stir at low speed under light-protected conditions. The stirring speed is 400 r / min and the stirring time is 2 h to obtain photosensitive resin.

[0096] (2) The prepared photosensitive resin was poured into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set as needed, resulting in a smooth and highly detailed model surface. After printing, the support of the sample blank was removed, and it was ultrasonically treated in ethanol for 10 minutes, followed by curing in a UV oven for 25 minutes to obtain the final 3D printed hydrogel ultrasonic phantom. The test results showed that the sound velocity of the hydrogel was 1508±9 m / s, the sound attenuation coefficient was 0.57±0.03 dB / cm·MHz, and the density was 1.07 kg / m³. 3 .

[0097] Example 4

[0098] This embodiment first provides an aqueous polyurethane methacrylate emulsion, the preparation method of which is as follows:

[0099] S1. Add polyethylene glycol (60.0 g, 0.03 mol) and polyethylene glycol-polypropylene glycol copolymer (PPG-PPG) to hexamethylene diisocyanate (16.8 g, 0.1 mol). L-121 (132.0g, 0.03mol) and catalyst 0.02g n-butyltin laurate were used to maintain the reaction system temperature at 90℃. The reaction was continued until the characteristic absorption peak of isocyanate in the infrared spectrum no longer decreased, and isocyanate-terminated polyurethane resin was obtained.

[0100] S2. React isocyanate-terminated polyurethane resin with hydroxyethyl acrylate (9.28g, 0.08mol), add 0.05g of polymerization inhibitor hydroquinone, and react at 55℃ until the reaction is complete and the characteristic absorption peak of the isocyanate group in the infrared spectrum completely disappears to obtain waterborne polyurethane acrylate.

[0101] S3. Cool the system to room temperature, add 270.9 g of deionized water dropwise while stirring at high speed (600 r / min), remove the organic solvent by vacuum distillation, and obtain an aqueous polyurethane acrylate emulsion with a solid content of 30% (average particle size of 45 nm according to dynamic light scattering test).

[0102] This embodiment also provides a method for preparing a 3D-printed ultrasonic phantom hydrogel material, including the following steps:

[0103] (1) Preparation of photosensitive resin:

[0104] The raw materials are weighed according to the formula ratio. The specific raw material components of the 3D printed ultrasonic phantom hydrogel material are as follows, by weight:

[0105]

[0106]

[0107] Mix all raw materials and stir at low speed under light-protected conditions. The stirring speed is 400 r / min and the stirring time is 2 h to obtain photosensitive resin.

[0108] (2) The prepared photosensitive resin was poured into the resin tank of the DLP 3D printing equipment for model printing. The printing parameters of the 3D printer were set as needed, resulting in a smooth and highly detailed model surface. After printing, the support of the sample blank was removed, and it was ultrasonically treated in ethanol for 10 minutes, followed by curing in a UV oven for 25 minutes to obtain the final 3D printed hydrogel ultrasonic phantom. The test results showed that the sound velocity of the hydrogel was 1518±9 m / s, the sound attenuation coefficient was 0.68±0.03 dB / cm·MHz, and the density was 1.07 kg / m³. 3 .

[0109] Comparative Example 1

[0110] The difference from Example 3 is that the photocurable monomers are acryloylmorpholine and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 1:0.2, while the total amount of photocurable monomers remains unchanged.

[0111] Comparative Example 2

[0112] The difference from Example 3 is that the photocurable monomers are acryloylmorpholine and 2-acrylamide-2-methylpropanesulfonic acid in a mass ratio of 1:0.8, while the total amount of photocurable monomers remains unchanged.

[0113] Comparative Example 3

[0114] The difference from Example 3 is that the only photocurable monomer is acrylomorpholine, while the total amount of photocurable monomer remains unchanged.

[0115] Comparative Example 4

[0116] The difference from Example 3 is that the only photocurable monomer is 2-acrylamide-2-methylpropanesulfonic acid, while the total amount of photocurable monomer remains unchanged.

[0117] Comparative Example 5

[0118] The difference from Example 2 is that 2-acrylamide-2-methylpropanesulfonic acid in the photocurable monomer is replaced with an equal amount of acrylic acid.

[0119] Experimental Example 1

[0120] The 3D-printed hydrogel ultrasonic phantoms prepared in the above embodiments and comparative examples were soaked in water for three days, then removed and dried. Their mechanical properties were then tested according to the GB / T2567-2008 test standard. Figure 4 The tensile curves of the hydrogel material in Example 2 are shown in Table 1 below. The specific test results are shown in Table 1 below.

[0121] Table 1

[0122] Group Tensile strength (MPa) Elongation at break (%) Fracture energy (mJ) Example 1 0.067 459.9 44.6 Example 2 0.058 491.2 37.3 Example 3 0.104 612.3 77.9 Example 4 0.036 262.6 12.9 Comparative Example 1 0.009 178.6 2.4 Comparative Example 2 0.125 192.6 15.3 Comparative Example 3 0.003 152.1 0.8 Comparative Example 4 0.525 48.5 32.3 Comparative Example 5 0.032 523.2 20.3

[0123] As shown in the table, the hydrogel ultrasonic phantoms prepared in the embodiments of the present invention exhibit high tensile strength, high elongation at break, excellent tensile properties, and high fracture energy. Compared with the embodiments, Comparative Examples 2 and 4 have a higher content of photocurable monomers containing sulfonic acid groups, which improves tensile strength but reduces elongation at break, indicating that the resulting hydrogel ultrasonic phantoms are more brittle. Comparative Examples 1, 3, and 5 show a decrease in tensile strength and elongation at break, resulting in decreased mechanical properties. This demonstrates that the selection of photocurable monomers has a significant impact on the mechanical properties of hydrogel ultrasonic phantoms.

[0124] Experimental Example 2

[0125] The anti-swelling performance of the 3D-printed hydrogel ultrasonic phantoms prepared in the above embodiments and comparative examples was evaluated by testing the mass change after immersion in water for three days. The specific test method was as follows: First, the mass (m0) of the cured hydrogel sample was measured. Then, the hydrogel sample was immersed in water, and the sample was removed after 3 days. The mass change of the hydrogel ultrasonic phantom material in Example 2 after immersion in water over time is shown in the figure. Figure 5 As shown, wipe the surface dry with absorbent paper and weigh the sample (m1). The test results are shown in Table 2 below.

[0126] Table 2

[0127] Group Quality change rate (%) Example 1 103 Example 2 108 Example 3 95 Example 4 120 Comparative Example 1 180 Comparative Example 2 58 Comparative Example 3 325 Comparative Example 4 35 Comparative Example 5 130

[0128] As shown in the table, the hydrogel ultrasonic phantoms prepared in the embodiments of the present invention exhibit moderate mass change rates and good anti-swelling properties. Compared to Example 3, Comparative Examples 1, 3, and 5 have lower contents of photocurable monomers containing sulfonic acid groups, resulting in significantly increased mass change rates and poorer anti-swelling properties of the hydrogels. In contrast, Comparative Examples 2 and 4 have excessively high contents of photocurable monomers containing sulfonic acid groups, leading to severe shrinkage of the hydrogels in water. Therefore, the choice of photocurable monomers affects the anti-swelling properties of the hydrogel ultrasonic phantoms. To maintain the shape of the cured hydrogel, it is necessary to add an appropriate amount of monomers containing sulfonic acid groups.

[0129] As can be seen from Tables 1 and 2, the ratio of sulfonic acid-containing photocurable monomers to waterborne photocurable monomers must be within a certain range to achieve good mechanical properties and anti-swelling properties in the hydrogel. Too little sulfonic acid-containing photocurable monomer results in poor hydrogel strength and poor anti-swelling properties; too much results in high hydrogel strength but low elongation at break and brittleness. When the ratio of sulfonic acid-containing photocurable monomers to waterborne photocurable monomers is within the range of 1:0.3–0.7, the resulting hydrogel supermold exhibits both excellent mechanical properties and anti-swelling properties.

[0130] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A hydrogel material for 3D printing ultrasonic phantoms, characterized in that, Contains the following ingredients by weight: The composition includes 5-20 parts of waterborne polyurethane acrylate emulsion, 6-30 parts of photocurable monomer, 1-10 parts of inorganic salt, 1-5 parts of scattering agent, 1-5 parts of stabilizer, 70-90 parts of deionized water, 0.1-5 parts of photoinitiator, and 0.001-0.5 parts of light absorber; among which, The photocurable monomer comprises an aqueous photocurable monomer and a sulfonic acid-containing photocurable monomer in a mass ratio of 1:(0.3-0.7).

2. The 3D-printed ultrasonic phantom hydrogel material according to claim 1, characterized in that, The 3D printed ultrasonic phantom hydrogel material comprises the following raw materials in parts by weight: 8-14 parts of waterborne polyurethane acrylate emulsion, 11-13 parts of photocurable monomer, 3-5 parts of inorganic salt, 1-2 parts of scatterer, 1-3 parts of stabilizer, 70-72 parts of deionized water, 1-2 parts of photoinitiator, and 0.01-0.1 parts of light absorber.

3. The 3D-printed ultrasonic phantom hydrogel material according to claim 1, characterized in that, The photocurable monomer comprises an aqueous photocurable monomer and a sulfonic acid-containing photocurable monomer in a mass ratio of 1:(0.4-0.6).

4. The 3D-printed ultrasonic phantom hydrogel material according to claim 3, characterized in that, The water-soluble curing monomer is selected from at least one of acrylamide, acrylomorpholine, hydroxyethyl acrylate, N-isopropylacrylamide, methacrylamide, and N-vinylpyrrolidone; the sulfonic acid-containing photocuring monomer is selected from at least one of 2-acrylamido-2-methylpropanesulfonic acid, sodium p-styrenesulfonate, and sodium vinylsulfonate.

5. The 3D-printed ultrasonic phantom hydrogel material according to claim 1 or 2, characterized in that, The scatterer is selected from at least one of silicon dioxide, hydroxyapatite, and calcium phosphate.

6. The 3D-printed ultrasonic phantom hydrogel material according to claim 1 or 2, characterized in that, The stabilizer is selected from at least one of polyvinyl alcohol, hyaluronic acid, waterborne polyurethane, polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, and sodium stearate.

7. The 3D-printed ultrasonic phantom hydrogel material according to claim 1 or 2, characterized in that, The waterborne polyurethane acrylate emulsion is obtained by reacting diisocyanate with hydroxyl-terminated polyols and diols with hydrophilic groups to obtain an isocyanate-terminated prepolymer, which is then reacted with hydroxyl-containing acrylates or acrylates to obtain a polyurethane acrylate resin, which is then emulsified.

8. The method for preparing the 3D-printed ultrasonic phantom hydrogel material according to any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Mix all raw materials and stir at low speed under light-protected conditions to obtain photosensitive resin; (2) The photosensitive resin is printed by using photopolymerization 3D printing.

9. The preparation method according to claim 8, characterized in that, In step (2), after the printing is completed, the obtained sample is also cleaned and then cured.

10. The application of the 3D-printed ultrasonic phantom hydrogel material according to any one of claims 1 to 7 as an ultrasonic phantom in ultrasonic medicine.

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