A brain tissue phantom and its preparation method

Abstract

This application provides a brain tissue phantom and its preparation method, relating to the field of biomedical technology. The brain tissue phantom comprises the following raw materials by weight percentage: 45-55% egg source liquid, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interfaces, acoustic computer imaging, and ultrasound neuromodulation.

Description

Technical Field

[0001] This application relates to the field of biomedical technology, and in particular to a brain tissue phantom and its preparation method. Background Technology

[0002] Ultrasound neuromodulation, as an emerging non-invasive brain science research method, has become a research hotspot in the fields of neuroscience and brain-computer interfaces due to its excellent deep tissue penetration and millimeter-level spatial focusing capabilities. Ultrasound neuromodulation has also spawned cutting-edge branches such as ultrasound-modulated EEG (UM-EEG)—which utilizes acoustic-electric effects to break through the spatial resolution bottleneck of traditional electroencephalography (EEG) and achieve precise analysis of deep brain electrophysiological activity.

[0003] Currently, both precise neuromodulation and sophisticated ultrasound modulation of EEG signals rely heavily on deep multi-physics coupling between ultrasound waves and complex brain tissue current sources. Due to severe ethical constraints and biosafety challenges in in vivo experiments, current research urgently needs to simulate the physical characteristics of the real brain using highly biomimetic brain tissue phantoms in a controlled laboratory environment. Most existing ultrasound neuromodulation phantoms focus only on simulating the acoustic characteristics of ultrasound propagation (such as sound velocity and acoustic impedance) to meet the testing requirements for beam focusing and energy distribution. The low biomimetic performance of existing brain tissue phantoms hinders the widespread application of ultrasound brain-computer interfaces, acoustic computed tomography (CT) imaging, and ultrasound neuromodulation technologies. Summary of the Invention

[0004] This application provides a brain tissue phantom and its preparation method, aiming to solve the technical problem of low biomimetic performance of existing brain tissue phantoms and improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0005] In a first aspect, embodiments of this application provide a brain tissue phantom, the brain tissue phantom comprising the following raw materials by weight percentage: The mixture consists of 45-55% egg source clear liquid, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% promoter, and the remainder is physiological saline.

[0006] The brain tissue phantom provided in this application comprises the following raw materials by weight percentage: 45-55% egg white solution, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0007] In one possible implementation, the brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-55% egg source clear liquid, 8.5-9.5% acrylamide, 0.4-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.04-0.05% initiator, 0.14-0.15% promoter, and the remainder is physiological saline.

[0008] The brain tissue phantom provided in this embodiment comprises the following raw materials by weight percentage: 48-55% egg white solution, 8.5-9.5% acrylamide, 0.4-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.04-0.05% initiator, 0.14-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0009] In one possible implementation, the brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-50% egg source clear liquid, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% promoter, and the remainder is physiological saline.

[0010] The brain tissue phantom provided in this embodiment comprises the following raw materials by weight percentage: 48-50% egg white solution, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0011] In one possible implementation, the initiator includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0012] In one possible implementation, the promoter includes at least one of N,N,N',N'-tetramethylethylenediamine, sodium bisulfite, and N,N-dimethylaniline.

[0013] In one possible implementation, the egg source liquid includes poultry egg white liquid; the poultry egg white liquid includes at least one of chicken egg white liquid, duck egg white liquid, goose egg white liquid, and ostrich egg white liquid.

[0014] The brain tissue phantom provided in the above embodiments comprises the following raw materials by weight percentage: 45-55% egg source liquid, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% promoter, and the balance being physiological saline. This brain tissue-inspired phantom can be made more viscous by adding egg white liquid to the material, thus adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making it suitable for high-intensity focused ultrasound (HIFU) treatment of brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation research. Acrylamide, as the phantom's skeletal monomer, polymerizes under the action of an initiator to form a polyacrylamide hydrogel network, determining the phantom's mechanical strength and macroscopic morphology. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network structure, controlling the phantom's hardness and spatial stability. The addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the phantom's conductivity. Physiological saline provides free ions, making the phantom's conductivity close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, enabling it to be used for simulation and experimental research of ultrasound-modulated EEG signal technology, improving the biomimetic performance of phantoms in fields such as ultrasound brain-computer interfaces, acoustic computer imaging, and ultrasound neuromodulation.

[0015] Secondly, embodiments of this application provide a method for preparing a brain tissue phantom, the method comprising: Egg source liquid, acrylamide, N,N'-methylenebisacrylamide, silica, initiator, accelerator and physiological saline were mixed evenly and subjected to cross-linking reaction to obtain the brain tissue model.

[0016] The method for preparing a brain tissue-inspired phantom provided in this application includes: uniformly mixing egg white solution, acrylamide, N,N'-methylenebisacrylamide, silica, initiator, accelerator, and physiological saline, and performing a cross-linking reaction to obtain the brain tissue-inspired phantom. This method increases the viscosity of the phantom by adding egg white solution, while also adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation research. Acrylamide, as the scaffold monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional structure. The mesh structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, enabling the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties. This can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interfaces, acoustic computer imaging, and ultrasound neuromodulation.

[0017] In one possible implementation, the egg source liquid is obtained by the following method: Egg white liquid is extracted from poultry eggs, and the flocculent matter is removed to obtain the egg source liquid.

[0018] In one possible implementation, the preparation method includes: Acrylamide, N,N'-methylenebisacrylamide, and silica were added to physiological saline and mixed to obtain the first mixed solution. The first mixed solution is filtered to remove undissolved particles and impurities, resulting in a second mixed solution. The egg source solution is added to the second mixed solution to obtain a third mixed solution; The third mixed solution is degassed to eliminate air bubbles, resulting in a fourth mixed solution. The promoter is added to the fourth mixed solution and poured into a preset container. After solidification, the brain tissue model is obtained.

[0019] In one possible implementation, the temperature of the crosslinking reaction is 20~40°C.

[0020] The technical effects of any implementation of the second aspect can be found in the technical effects of the implementation of the first aspect, and will not be repeated here. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 A schematic diagram of a finished brain tissue phantom provided in this application embodiment; Figure 2 A schematic diagram of the structure of a testing device for a brain tissue phantom provided in an embodiment of this application; Figure 3 A schematic diagram showing the test results of a brain tissue phantom provided in an embodiment of this application; Figure 4 This is a schematic flowchart illustrating a method for preparing a brain tissue phantom provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] Ultrasound neuromodulation, as an emerging non-invasive brain science research method, has become a research hotspot in the fields of neuroscience and brain-computer interfaces due to its excellent deep tissue penetration and millimeter-level spatial focusing capabilities. Ultrasound neuromodulation has also spawned cutting-edge branches such as ultrasound-modulated EEG (UM-EEG)—which utilizes acoustic-electric effects to break through the spatial resolution bottleneck of traditional electroencephalography (EEG) and achieve precise analysis of deep brain electrophysiological activity.

[0025] Currently, both precise neuromodulation and sophisticated ultrasound modulation of EEG signals rely heavily on deep multi-physics coupling between ultrasound waves and complex brain tissue current sources. Due to severe ethical constraints and biosafety challenges in in vivo experiments, current research urgently needs to simulate the physical characteristics of the real brain using highly biomimetic brain tissue phantoms in a controlled laboratory environment. Most existing ultrasound neuromodulation phantoms focus only on simulating the acoustic characteristics of ultrasound propagation (such as sound velocity and acoustic impedance) to meet the testing requirements for beam focusing and energy distribution. The low biomimetic performance of existing brain tissue phantoms hinders the widespread application of ultrasound brain-computer interfaces, acoustic computed tomography (CT) imaging, and ultrasound neuromodulation technologies.

[0026] Based on this, this application provides a brain tissue phantom and its preparation method. The brain tissue phantom comprises the following raw materials by mass percentage: 45-55% egg white solution, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom and adds protein components, enabling it to simulate the denaturation reaction of tissue under ultrasound. This allows the phantom to be used for high-intensity focused ultrasound (HIFU) treatment of brain tumors and other diseases, as well as low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the scaffold monomer of the phantom, plays a crucial role in the initiation process. The formation of a polyacrylamide hydrogel network under the action of a catalyst determines the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network structure, controlling the hardness and spatial stability of the phantom. The addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom. Physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, enabling the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties. This can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interfaces, acoustic computer imaging, and ultrasound neuromodulation.

[0027] To make the inventive objectives, technical solutions, and advantages of the embodiments of this application clearer, the present application will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] The brain tissue phantom provided in the embodiments of this application will be further explained below.

[0029] This application provides a brain tissue phantom, which comprises the following raw materials by weight percentage: The mixture consists of 45-55% egg source clear liquid, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% promoter, and the remainder is physiological saline.

[0030] Specifically, in the raw materials of the brain tissue phantom, the mass content of the egg source liquid is 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, or any two of these values; the mass content of acrylamide is 7.5%, 7.6%, 7.7%, 7.8%, 7.9%, 8.0%, 8.1%, 8.2%, 8.3%, 8.4%, 8.5%, 8.6%, 8.7%, 8.8%, 8.9%, 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, or any two of these values; and the mass content of N,N'-methylenebisacrylamide is 0.1%, 0. The concentrations are as follows: 2%, 0.3%, 0.4%, 0.5%, or any two of these values; silica content is 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, or any two of these values; initiator content is 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, or any two of these values; accelerator content is 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14%, 0.15%, or any two of these values; the remainder is physiological saline.

[0031] The brain tissue phantom provided in this embodiment comprises the following raw materials by weight percentage: 45-55% egg white solution, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0032] In one possible implementation, the brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-55% egg source clear liquid, 8.5-9.5% acrylamide, 0.4-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.04-0.05% initiator, 0.14-0.15% promoter, and the remainder is physiological saline.

[0033] Specifically, in the raw materials of the brain tissue phantom, the mass content of the egg source liquid is 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, or any two of these values; the mass content of acrylamide is 8.5%, 8.6%, 8.7%, 8.8%, 8.9%, 9.0%, 9.1%, 9.2%, 9.3%, 9.4%, 9.5%, or any two of these values; the mass content of N,N'-methylenebisacrylamide is 0.4%, 0.5%, or any two of these values; the mass content of silica is 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.10%, or any two of these values; the mass content of the initiator is 0.04%, 0.05%, or any two of these values; the mass content of the promoter is 0.14%, 0.15%, or any two of these values; and the remainder is physiological saline.

[0034] The brain tissue phantom provided in this embodiment comprises the following raw materials by weight percentage: 48-55% egg white solution, 8.5-9.5% acrylamide, 0.4-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.04-0.05% initiator, 0.14-0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0035] In one possible implementation, the brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-50% egg source clear liquid, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% promoter, and the remainder is physiological saline.

[0036] The brain tissue phantom provided in this embodiment comprises the following raw materials by weight percentage: 48-50% egg white solution, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% accelerator, and the balance being physiological saline. This brain tissue phantom, by adding egg white solution to the material, increases the viscosity of the phantom while adding protein components. Under ultrasound, it can simulate the denaturation reaction of tissue, making the phantom suitable for high-intensity focused ultrasound (HIFU) treatment of diseases such as brain tumors and low-intensity focused ultrasound (HIFU) neuromodulation therapy research. Acrylamide, as the skeletal monomer of the phantom, polymerizes under the action of the initiator to form a polyacrylamide hydrogel network, determining the mechanical strength and macroscopic morphology of the phantom. N,N'-methylenebisacrylamide connects the acrylamide monomer chains into a three-dimensional network. The structure controls the rigidity and spatial stability of the phantom; the addition of silica can accurately simulate the scattering and attenuation characteristics of ultrasound waves in brain tissue, while adjusting the conductivity of the phantom; physiological saline provides free ions, making the conductivity of the phantom close to that of human brain tissue, thereby supporting the transmission of EEG signals. It can achieve acoustic and electrical properties close to those of human brain tissue, and can realize the construction of a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties, which can improve the biomimetic performance of phantoms in fields such as ultrasound brain-computer interface, acoustic computer imaging, and ultrasound neuromodulation.

[0037] In one possible implementation, the initiator includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

[0038] In one possible implementation, the promoter includes at least one of N,N,N',N'-tetramethylethylenediamine, sodium bisulfite, and N,N-dimethylaniline.

[0039] In one possible implementation, the egg source liquid includes poultry egg liquid; poultry egg liquid includes, but is not limited to, at least one of chicken egg liquid, duck egg liquid, goose egg liquid, and ostrich egg liquid.

[0040] This application provides a brain tissue phantom, the raw materials of which include the following components by mass percentage: The mixture consists of 48-50% egg white solution, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% promoter, and the remainder is physiological saline; the egg white solution is egg white solution.

[0041] This embodiment constructs a bimodal brain tissue phantom with both biomimetic acoustic and electrical properties by precisely proportioning various functional materials. At the level of biofunctional simulation, the introduction of egg white liquid not only thickens and stabilizes the natural biomolecules, but more importantly, its rich protein thermal denaturation mechanism endows the phantom with the ability to simulate coagulative necrosis of brain tissue under the ultrasonic thermal effect. This allows the phantom's applicability to successfully expand from low-intensity focused ultrasound (HIFU) neuromodulation to therapeutic assessment fields such as high-intensity focused ultrasound (HIFU) ablation of brain tumors. Regarding the phantom's skeletal construction and mechanical property control, acrylamide, as the core functional monomer, undergoes in-situ polymerization under the initiator's induction, generating a continuous polyacrylamide hydrogel matrix, thus endowing the phantom with stable macroscopic morphology and basic mechanical strength. Based on this, by adding the crosslinking agent N,N'-methylenebisacrylamide, a dense three-dimensional network crosslinking bridge is established between the polymer monomer chains, thereby achieving quantitative characterization and flexible adaptation of the phantom's elastic modulus, compressive strength, and spatial structural stability.

[0042] The embodiments of this application specifically introduce silica particles as sound scattering centers. By adjusting their particle size and mass fraction, the scattering and attenuation characteristics of ultrasound waves in real brain tissue can be accurately simulated, and the dielectric constant can be finely adjusted. At the same time, the abundant free ions in physiological saline provide stable conductivity, making the electrical impedance characteristics of the phantom highly consistent with those of human brain tissue. This provides a realistic and stable electrophysiological conduction environment for the generation, transmission, and acquisition of EEG signals under ultrasound modulation.

[0043] Figure 1 The image shows a finished product of a brain tissue phantom material according to this application. The brain tissue phantom material of this application has been found to have a sound velocity close to 1560 m / s of human brain tissue. The sound attenuation is close to 0.6 dB / cm, which is similar to the acoustic properties of human brain tissue. Meanwhile, at a frequency of 1.1 MHz, the relative permittivity is close to 240, and the conductivity is close to... Its electrical properties are similar to those of human brain tissue, which can be used for simulation and experimental research of ultrasound-modulated electroencephalogram (EEG) signals, and will help promote the application of ultrasound brain-computer interfaces, acoustic computer imaging, and ultrasound neuromodulation technology.

[0044] This application also discloses a method for preparing the above-mentioned brain tissue phantom material, including the following process: Step 1) Preparation of egg white liquid: Egg white is separated from fresh eggs, and translucent or milky white flocculent protein structures (such as chalazae and concentrated protein components) are thoroughly removed using a fine filter or physical picking method. A clear egg white phase with uniform properties and good light transmittance is obtained, ensuring that the protein components are evenly distributed in subsequent polymerization reactions, thereby providing the phantom with stable biothermal sensitive properties and a viscoelastic matrix.

[0045] Step 2) Prepare the mixed solution: Precisely weighed acrylamide, N,N'-methylenebisacrylamide, silica, and initiator were sequentially added to physiological saline. The mixture was thoroughly stirred using a magnetic stirrer or a high-shear mixer. By controlling the rotation speed and time, complete dissolution of the monomers and crosslinking agents was ensured, and the silica particles were uniformly suspended in an ionic environment. This process established the conductive substrate of the phantom through the ionic concentration of the physiological saline, while the diffuse distribution of silica initially constructed the acoustic scattering background.

[0046] Step 3) Solution filtration: Quantitative filter paper or microporous filters are used to thoroughly intercept incompletely dissolved microparticles and foreign impurities, preventing acoustic impedance mismatch or electric field distortion caused by local density unevenness. The filtered solution is clear and transparent, laying the foundation for obtaining defect-free, highly isotropic phantom entities.

[0047] Step 4) Solution degassing and homogenization: The egg white liquid obtained in step 1) is slowly introduced into the filtered solution obtained in step 3) and mixed at a low speed in the dark to prevent premature protein denaturation. Subsequently, the resulting mixed emulsion is placed in a high-vacuum degassing chamber for thorough degassing, using a pressure gradient to force out dissolved microbubbles. This step is crucial for ensuring the acoustic properties of the phantom, eliminating abnormal scattering points in the ultrasound propagation path and preventing severe cavitation interference or signal attenuation caused by bubbles.

[0048] Step 5) Cooling and curing: The accelerator TEMED was added to the degassed solution to accelerate the free radical polymerization reaction. The reaction solution was then immediately injected into a pre-prepared mold. Under controlled temperature and humidity, the acrylamide monomer rapidly underwent a cross-linking reaction under the action of a cross-linking agent, forming a polyacrylamide-egg white composite hydrogel with a stable spatial configuration. After the system completely solidified in situ, a brain tissue-inspired model was formed.

[0049] The following are specific examples.

[0050] Example 1

[0051] A brain tissue-inspired phantom, the raw materials of which comprise the following components by weight percentage: The mixture consisted of 48% egg white liquid, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05% silica, 0.05% ammonium persulfate initiator, 0.15% TEMED accelerator, and the remainder was physiological saline.

[0052] 1) Extract egg white from fresh eggs, remove chalazae and translucent flocculent impurities through physical sorting to obtain a homogeneous and clear protein solution.

[0053] 2) Acrylamide, N,N'-methylenebisacrylamide, silica, and crosslinking agent powder are dissolved in physiological saline in a specific ratio and stirred thoroughly. Undissolved impurities are then filtered to eliminate physical defects that could lead to electric field distortion or acoustic hard spots.

[0054] 3) Inject the pretreated egg white liquid into the above filtrate and perform thorough degassing under vacuum.

[0055] 4) Add the accelerator TEMED to the degassed mixture and quickly pour it into a special mold. After the hydrogel system crosslinks and solidifies, a biomimetic phantom with a stable spatial structure and acoustic and electrical parameters that accurately correspond to brain tissue is obtained.

[0056] Example 2

[0057] The difference between Example 2 and Example 1 is that the egg white liquid has a mass fraction of 52%, the acrylamide mass ratio is 8.5%, and the N,N'-methylenebisacrylamide mass ratio is 0.4%.

[0058] Example 3

[0059] The difference between Example 3 and Example 1 is that the egg white liquid contains 55% by mass and 0.04% ammonium persulfate as an initiator.

[0060] Example 4

[0061] The difference between Example 4 and Example 1 is that the accelerator TEMED has a silica mass fraction of 0.10% and 0.14%.

[0062] Example 5

[0063] Compared with Example 1, Example 5 differs in that it contains 50% egg white liquid, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05% silica, 0.05% ammonium persulfate initiator, 0.15% TEMED accelerator, and the remainder is physiological saline.

[0064] Example 6

[0065] The difference between Example 6 and Example 1 is that Example 6 contains 45% egg white liquid, 7.5% acrylamide, 0.1% N,N'-methylenebisacrylamide, 0.08% silica, 0.01% ammonium persulfate initiator, 0.05% TEMED accelerator, and the remainder is physiological saline.

[0066] Example 7

[0067] The difference between Example 7 and Example 1 is that duck egg white liquid is used instead of chicken egg white liquid. The preparation method of duck egg white liquid is the same as that of chicken egg white liquid in Example 1, and will not be repeated here.

[0068] Comparative Example 1

[0069] Comparative Example 1 differs from Example 1 in its components, but the preparation process is completely similar.

[0070] Specifically, a brain tissue-inspired phantom is made from the following components by weight percentage: The mixture consisted of 50% egg white solution, 9% acrylamide, 0.5% N,N'-methylenebisacrylamide, 5% glycerol, 0.05% ammonium persulfate initiator, and 0.15% TEMED accelerator, with the remainder being physiological saline.

[0071] Comparative Example 2

[0072] The difference between Comparative Example 2 and Example 1 is that the raw material components do not include silicon dioxide.

[0073] Comparative Example 3

[0074] The difference between Comparative Example 3 and Example 1 is that the mass fraction of silicon dioxide is 0.2%.

[0075] Comparative Example 4

[0076] The difference between Comparative Example 4 and Example 1 is that the mass fraction of silicon dioxide is 0.03%.

[0077] Comparative Example 5

[0078] Compared with Example 1, Comparative Example 5 differs in that egg liquid is used instead of egg white liquid; the preparation method of egg liquid is as follows: fresh eggs are broken and mixed evenly, and the chalazae and translucent flocculent impurities are removed by physical sorting to obtain uniform egg liquid.

[0079] Comparative Example 6

[0080] The difference between Comparative Example 6 and Example 1 is that the content of egg white liquid is 40 wt%.

[0081] Comparative Example 7

[0082] The difference between Comparative Example 7 and Example 1 is that the content of egg white liquid is 60 wt%.

[0083] Test Example 1

[0084] Test conditions: This test follows the insertion substitution method recommended in GB / T 15261-2008 "Measurement Methods for Acoustic Properties of Ultrasonic Tissue-like Materials". The test is conducted in a degassed water bath at a specific water temperature. The transducer spacing was 10cm, and the test frequency was 3MHz.

[0085] The acoustic properties of Examples 1-7, Comparative Examples 1-7, and real brain tissue are shown in Table 1.

[0086] Table 1: Acoustic characteristics of the brain tissue model

[0087] Table 1 shows that Examples 1-7 can better simulate the acoustic properties of brain tissue compared to Comparative Examples 1-7.

[0088] Test Example 2

[0089] Test conditions: This test uses the parallel plate electrode method, and the test frequency is selected as 1.1MHz to match the mainstream operating frequency band of focused ultrasound neuromodulation. An AC excitation signal is applied at 1.1MHz using an impedance analyzer (or a high-frequency LCR meter) to measure the complex impedance of the sample. By obtaining the impedance amplitude and phase angle The relative permittivity of the phantom was further derived. and conductivity .

[0090] The electrical properties of Examples 1-7, Comparative Examples 1-7, and real brain tissue (white matter) are shown in Table 2.

[0091] Table 2: Electrical properties of the brain tissue model

[0092] Table 2 shows that Examples 1-7 can better simulate the electrical properties of brain tissue compared to Comparative Examples 1-7.

[0093] Test Example 3

[0094] The brain-like tissue phantom material prepared in Example 1 was placed in a phased array testing system. The phased array testing system, as the testing device, can be as follows: Figure 2As shown, in some embodiments of this application, the testing apparatus includes: a phased array control system, a phantom fixing device, an ultrasonic transducer, and a water tank. During the test, the position of the brain-like tissue phantom material remains unchanged, and the initial excitation voltage of each element of the phased array is set to 6V to verify the changes of the brain-like tissue phantom material under ultrasonic thermal effects, and the ability of the ultrasonic target point to be regulated and moved within the brain-like tissue phantom material. The focus of the ultrasonic transducer is sequentially preset at (0, 0, 58), (0, 0, 59), (0, 0, 60), (0, 0, 61), and (0, 0, 62), and the results are as follows. Figure 3 As shown. By Figure 3 It can be seen that protein denaturation occurred at the focal position of the brain tissue phantom, a white focal region appeared in the brain tissue phantom, and the focal position was controlled and focused on the acoustic axis.

[0095] In some embodiments of this application, the ultrasonic transducer is a 128-element phased array transducer.

[0096] In some embodiments of this application, the size of the brain tissue phantom material used for testing is 40mm × 40mm × 30mm.

[0097] This application also provides a method for preparing a brain tissue phantom, the method comprising: Egg source liquid, acrylamide, N,N'-methylenebisacrylamide, silica, initiator, accelerator and physiological saline were mixed evenly and cross-linked to obtain a brain tissue model.

[0098] In one possible implementation, the egg source liquid is obtained through the following method: Egg white liquid is extracted from poultry eggs, and the flocculent matter is removed to obtain egg source liquid.

[0099] In one possible implementation, egg source liquid, acrylamide, N,N'-methylenebisacrylamide, silica, initiator, accelerator, and physiological saline are mixed evenly and subjected to a cross-linking reaction to obtain a brain tissue-inspired model, such as... Figure 4 As shown, it includes: Step S401: Acrylamide, N,N'-methylenebisacrylamide, and silica are added to physiological saline and mixed to obtain the first mixed solution.

[0100] Step S402: Filter the first mixed solution to remove undissolved particles and impurities, and obtain the second mixed solution.

[0101] Step S403: Add egg source clear liquid to the second mixed solution to obtain the third mixed solution.

[0102] Step S404: Degas the third mixed solution to eliminate air bubbles and obtain the fourth mixed solution.

[0103] In step S405, an accelerator is added to the fourth mixed solution and poured into a preset container. After solidification, a brain tissue model is obtained.

[0104] In practice, an accelerator is added to the fourth mixed solution and quickly poured into a pre-set container. After solidification, a brain tissue model is obtained.

[0105] In one possible implementation, the crosslinking reaction temperature is 20~40℃.

[0106] In practice, during the preparation of the brain tissue model, the cross-linking reaction temperature can be room temperature, typically 20~40℃.

[0107] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A brain tissue-inspired phantom, characterized in that, The brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 45-55% egg source clear liquid, 7.5-9.5% acrylamide, 0.1-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.01-0.05% initiator, 0.05-0.15% promoter, and the remainder is physiological saline.

2. The brain tissue phantom according to claim 1, characterized in that, The brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-55% egg source clear liquid, 8.5-9.5% acrylamide, 0.4-0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.04-0.05% initiator, 0.14-0.15% promoter, and the remainder is physiological saline.

3. The brain tissue phantom according to claim 1, characterized in that, The brain tissue phantom comprises the following raw materials by weight percentage: The mixture consists of 48-50% egg source clear liquid, 9.5% acrylamide, 0.5% N,N'-methylenebisacrylamide, 0.05-0.10% silica, 0.05% initiator, 0.15% promoter, and the remainder is physiological saline.

4. The brain tissue phantom according to claim 1, characterized in that, The initiator includes at least one of ammonium persulfate, potassium persulfate, and sodium persulfate.

5. The brain tissue phantom according to claim 1, characterized in that, The accelerator includes at least one of N,N,N',N'-tetramethylethylenediamine, sodium bisulfite, and N,N-dimethylaniline.

6. The brain tissue phantom according to claim 1, characterized in that, The egg source liquid includes poultry egg white liquid; the poultry egg white liquid includes at least one of chicken egg white liquid, duck egg white liquid, goose egg white liquid, and ostrich egg white liquid.

7. A method for preparing a brain tissue phantom, characterized in that, The preparation method includes: Egg source liquid, acrylamide, N,N'-methylenebisacrylamide, silica, initiator, accelerator and physiological saline are mixed evenly and cross-linked to obtain the brain tissue model.

8. The preparation method according to claim 7, characterized in that, The egg source solution was obtained through the following method: Egg white liquid is extracted from poultry eggs, and the flocculent matter is removed to obtain the egg source liquid.

9. The preparation method according to claim 7, characterized in that, The preparation method includes: Acrylamide, N,N'-methylenebisacrylamide, and silica were added to physiological saline and mixed to obtain the first mixed solution. The first mixed solution is filtered to remove undissolved particles and impurities, resulting in a second mixed solution. The egg source solution is added to the second mixed solution to obtain a third mixed solution; The third mixed solution is degassed to eliminate air bubbles, resulting in a fourth mixed solution. The promoter is added to the fourth mixed solution and poured into a preset container. After solidification, the brain tissue model is obtained.

10. The preparation method according to claim 7, characterized in that, The cross-linking reaction is carried out at a temperature of 20~40℃.

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