CN113706983A - Brain model and preparation method thereof - Google Patents

Abstract

The invention relates to a brain model and a preparation method thereof, wherein the brain model comprises the following components: a healthy brain model, a brain model provided with a bleeding point model and a brain model provided with an ischemia point model; and provides a corresponding manufacturing method; simultaneously this application has designed different perfusates to brain inner structure respectively, includes: cerebrospinal fluid perfusate, gray matter perfusate, white matter perfusate, cerebellum perfusate, brainstem perfusate, bleeding point perfusate and ischemia point perfusate; and provides a corresponding preparation method; the brain model obtained through the configuration of the application has the advantages that the dielectric constant, the loss angle and the true value are close, the separation degree is good, and the fact that layers are fused and confused with each other can be guaranteed.

Description

Brain model and preparation method thereof

Technical Field

The invention relates to the technical field of microwave medical imaging, human body models, ischemia and hemorrhagic stroke monitoring, in particular to a brain model and a preparation method thereof.

Background

The brain model preparation method studied at home and abroad mainly comprises two methods:

the first is formulated using solid materials such as corn flour, wheat flour, etc. For the first configuration, this type of brain model loses water very quickly, the dielectric constant is unstable, and the manufacturing process is complex.

The second is the use of liquid raw materials for preparation, such as safflower oil, kerosene, etc. For the second manufacturing method, firstly, only one or two simple mixture ratios are designed for the research of the mode, and few people research and manufacture complex models with multiple tissues. Second, the degree of separation of the model is not discussed, since in the production of complex brain models, a variety of different tissues are involved, which are easily fused after perfusion, leading to perfusion failure. Finally, most of the kerosene is used as a stabilizer to ensure uniformity, but the addition of kerosene not only complicates the manufacturing process, but also has some toxicity.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to: the brain model configuration method is characterized in that liquid raw materials are used for configuring the brain model, and the brain model configuration method with very accurate dielectric constant and Loss angle (Loss tangent) is obtained. The brain model obtained by the brain model configuration method provided by the application has good separation degree, can be configured for complex brain models, and ensures that layers are not fused and confused with each other. In the actual process, the problem of uniformity is solved through complex temperature control, kerosene is not needed, and the method is simple and convenient. The brain model prepared by the method has a good shelf life and changes along with time, and the dielectric constant of the prepared brain model changes very little within two months.

In order to achieve the above purposes, the technical scheme adopted by the invention is as follows:

in a first aspect, the present invention provides a perfusate comprising: 40-120 mL of distilled water, 10-25 g of coagulant, 0.1-3 g of sodium chloride, 1-60 mL of oil and 10-35 mL of emulsifier.

Preferably, the emulsifier is: O/W type water-oil emulsifier.

Preferably, the emulsifier comprises: a liquid detergent.

Preferably, the oils are: an oil having a dielectric constant of 3 to 7.

Preferably, the oils are: and (3) vegetable oil.

Preferably, said oils comprise: rapeseed oil and olive oil.

Preferably, the coagulant comprises: gelatin and Geliding powder.

Preferably, the perfusate further comprises: and (4) a preservative.

Preferably, the preservative comprises: n-propanol, sodium azide and p-toluic acid.

Preferably, the contents of the n-propanol, the sodium azide and the p-toluic acid are respectively as follows: 3-6.5 mL of n-propanol, 0.5-2 g of sodium azide and 0.1-0.2 g of p-toluic acid.

In a second aspect, the present invention provides the use of a perfusate for preparing a brain model.

Preferably, the perfusate is used for preparing a cerebrospinal fluid model, a gray matter model, a white matter model, a cerebellum model, a brainstem model, a bleeding point model and an ischemia point model.

In a third aspect, the invention provides a perfusate for a brain internal structure model, which comprises a cerebrospinal fluid perfusate, a gray matter perfusate, a white matter perfusate, a cerebellum perfusate, a brainstem perfusate, a bleeding point perfusate and an ischemia point perfusate.

Preferably, the cerebrospinal fluid perfusate comprises the following components in percentage by weight: 78-117 mL of distilled water, 1.9-2.9 mL of olive oil, 15.7-23.7 g of Geliding powder, 12.4-18.8 mL of emulsifier and 1.3-2.1 g of sodium chloride.

Preferably, the cerebrospinal fluid perfusate comprises the following components in percentage by weight: 78-117 mL of distilled water, 1.9-2.9 mL of olive oil, 15.7-23.7 g of Geliding powder, 12.4-18.8 mL of emulsifier, 3.2-5.0 mL of n-propanol, 0.8-1.2 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.3-2.1 g of sodium chloride.

Preferably, the grey matter perfusate contains the following components in percentage by weight: 70.6-106.0 mL of distilled water, 9.3-14.1 mL of olive oil, 15.0-22.6 g of geridine powder, 14.3-21.5 mL of emulsifier and 0.6-0.9 g of sodium chloride.

Preferably, the grey matter perfusate contains the following components in percentage by weight: 70.6-106.0 mL of distilled water, 9.3-14.1 mL of olive oil, 15.0-22.6 g of geridine powder, 14.3-21.5 mL of emulsifier, 3.5-5.3 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.6-0.9 g of sodium chloride.

Preferably, the white matter perfusate contains the following components in percentage by weight: 52.4-78.8 mL of distilled water, 27.5-41.3 mL of olive oil, 13.2-20.0 g of Geliding powder, 18.8-28.4 mL of emulsifier and 0.5-0.8 g of sodium chloride.

Preferably, the white matter perfusate contains the following components in percentage by weight: 52.4-78.8 mL of distilled water, 27.5-41.3 mL of olive oil, 13.2-20.0 g of geridine powder, 18.8-28.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.4 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.8 g of sodium chloride.

Preferably, the cerebellum perfusate contains the following components in percentage by weight: 67.4-101.2 mL of distilled water, 12.5-18.9 mL of olive oil, 14.7-22.1 g of geridine powder, 15.1-22.7 mL of emulsifier and 1.1-1.7 g of sodium chloride.

Preferably, the cerebellum perfusate contains the following components in percentage by weight: 67.4-101.2 mL of distilled water, 12.5-18.9 mL of olive oil, 14.7-22.1 g of geridine powder, 15.1-22.7 mL of emulsifier, 3.6-5.4 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.7 g of sodium chloride.

Preferably, the perfusate for the brainstem comprises the following components in percentage by weight: 49.6-74.6 mL of distilled water, 30.3-45.5 mL of olive oil, 12.9-19.5 g of geridine powder, 19.6-29.4 mL of emulsifier and 0.5-0.9 g of sodium chloride.

Preferably, the perfusate for the brainstem comprises the following components in percentage by weight: 49.6-74.6 mL of distilled water, 30.3-45.5 mL of olive oil, 12.9-19.5 g of geridine powder, 19.6-29.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.9 g of sodium chloride.

Preferably, the bleeding point perfusate comprises the following components in percentage by weight: 72.9-109.5 mL of distilled water, 7.0-10.6 mL of olive oil, 15.2-23 g of Geliding powder, 13.7-20.7 mL of emulsifier and 1.1-1.8 g of sodium chloride.

Preferably, the bleeding point perfusate comprises the following components in percentage by weight: 72.9-109.5 mL of distilled water, 7.0-10.6 mL of olive oil, 15.2-23 g of geridine powder, 13.7-20.7 mL of emulsifier, 3.4-5.2 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.8 g of sodium chloride.

Preferably, the perfusate of the ischemia point comprises the following components in percentage by weight: 41.5-62.3 mL of distilled water, 38.4-57.8 mL of olive oil, 12.1-18.3 g of geridine powder, 21.6-32.4 mL of emulsifier and 0.4-0.8 g of sodium chloride.

Preferably, the perfusate of the ischemia point comprises the following components in percentage by weight: 41.5-62.3 mL of distilled water, 38.4-57.8 mL of olive oil, 12.1-18.3 g of geridine powder, 21.6-32.4 mL of emulsifier, 4.3-6.5 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.4-0.8 g of sodium chloride.

In a fourth aspect, the invention provides a preparation method of a perfusate for a brain internal structure model, which specifically comprises the following steps:

step 1: weighing the preservative, stirring and heating until the preservative is completely dissolved to obtain a solution I;

step 2: mixing the solution I with distilled water, and then adding a coagulant into the solution I to be fully stirred to obtain a mixed solution;

and step 3: heating the mixed solution, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the mixed solution becomes transparent;

and 4, step 4: cooling, measuring oil, and fully stirring and mixing the oil and the mixed solution obtained in the step (3) until the oil and the mixed solution become uniform to obtain a solution II;

and 5: and measuring an emulsifier, adding the emulsifier into the solution II, continuously stirring to obtain an emulsion, adding sodium chloride when the emulsion becomes uniform and white, and cooling to obtain a perfusate.

In a fifth aspect, the invention provides a brain model comprising: a healthy brain model, a brain model provided with a bleeding point model, or a brain model provided with an ischemia point model;

preferably, the healthy brain model comprises: a brain shell model and a brain internal structure model; the brain internal structure model includes: gray matter model, white matter model, cerebellum model, and brainstem model.

Preferably, the brain model provided with the bleeding point model includes: a brain shell model and a brain internal structure model; the brain internal structure model includes: gray matter model, white matter model, cerebellum model, brainstem model and bleeding point model.

Preferably, the brain model provided with the ischemia point model includes: a brain shell model and a brain internal structure model; the brain internal structure model includes: gray matter model, white matter model, cerebellum model, brainstem model and ischemia point model.

Preferably, the bleeding point model or the ischemia point model are hemispheres with the diameter of 1-3 cm.

Preferably, the bleeding point model or the ischemia point model are hemispheres each having a diameter of 2 cm.

Preferably, the ischemia point model or the hemorrhage point model is provided with a micro hook, so that the ischemia point model or the hemorrhage point model is convenient to disassemble and assemble.

In a sixth aspect, the present invention provides a method for preparing a brain model, comprising the following steps:

s1, manufacturing a brain shell model and a brain internal structure model of a resin material by using a 3D printing technology;

s2, preparing perfusate of the internal structure model of the brain;

and S3, performing layered perfusion on the shell model and the internal brain structure model of the brain model by using the perfusate obtained in the step S2, and pressing to obtain the brain model.

Preferably, the perfusion fluid described in step S2 is configured by liquid raw materials.

Preferably, the perfusate in step S2 includes: 40-120 mL of distilled water, 10-25 g of coagulant, 0.1-3 g of sodium chloride, 1-60 mL of oil and 10-35 mL of emulsifier.

Preferably, the emulsifier is: O/W type water-oil emulsifier.

Preferably, the emulsifier comprises: a liquid detergent.

Preferably, the oils are: an oil having a dielectric constant of 3 to 7.

Preferably, the oils are: and (3) vegetable oil.

Preferably, said oils comprise: rapeseed oil and olive oil.

Preferably, the coagulant comprises: gelatin and Geliding powder.

Preferably, the perfusate further comprises: and (4) a preservative.

Preferably, the preservative comprises: n-propanol, sodium azide and p-toluic acid.

Preferably, the contents of the n-propanol, the sodium azide and the p-toluic acid are respectively as follows: 3-6.5 mL of n-propanol, 0.5-2 g of sodium azide and 0.1-0.2 g of p-toluic acid.

Preferably, the brain model comprises a healthy brain model, a brain model with a bleeding point model or a brain model with an ischemia point model.

Preferably, the internal structure comprises: cerebrospinal fluid, gray matter, white matter, cerebellum, brainstem, bleeding spots and ischemic spots.

Preferably, the internal structure model comprises: gray matter model, white matter model, cerebellum model, brainstem model, bleeding point model, and ischemia point model.

Preferably, the bleeding point model is a hemisphere with the diameter of 1-3 cm.

Preferably, the bleeding point model is a hemisphere with a diameter of 2 cm.

Preferably, the ischemia point model is a hemisphere with the diameter of 1-3 cm.

Preferably, the ischemia point model is a hemisphere with a diameter of 2 cm.

Preferably, the brain model is provided with micro-hooks on a hemisphere.

Preferably, the bleeding point model is provided with a micro-hook on a hemisphere.

Preferably, the ischemia point model is provided with a micro-hook on a hemisphere.

Preferably, the brain model is stored in a refrigerator at a temperature of 4 ℃.

The invention has the beneficial effects that:

1. according to the method, the liquid raw materials are used for brain configuration, and the model configuration method with very accurate dielectric constant and loss angle is obtained. The electromagnetic property of the brain model is within the range indicated in the application, and the effect is stable through experimental tests. The separation degree is good, the configuration of a complex brain model can be carried out, and the layers are not fused and confused with each other.

2. The method solves the problem of uniformity through complex temperature control, can not use kerosene, is simple and convenient, has a good quality guarantee period, and changes the dielectric constant of the configured brain model very little within two months along with the change of time.

3. The materials used in the application are simple and easy to obtain, and related equivalent substitutes are provided, so that accurate results can be obtained conveniently according to the formula in any area.

4. The application designs the detachable module to simulate three different conditions of 'health', 'hemorrhage' and 'ischemia'. For three different medical conditions, the same human brain model can be used for experiments, and the efficiency is greatly improved. In addition, some medical imaging techniques require the use of "differential" techniques, i.e., the need for health as a priori information to assist in imaging the diseased condition. If multiple brain models are made for testing, it is difficult to ensure that each model is completely identical. The detachable model perfectly solves the problem.

Drawings

The invention has the following drawings:

fig. 1 is a schematic diagram of a human brain model i.

Fig. 2 is a schematic diagram of a human brain model ii.

FIG. 3 is a diagram illustrating the relationship between the measured dielectric constant and the frequency.

Fig. 4 is a schematic diagram of the relationship between the measured loss angle and the frequency.

FIG. 5 is a graph showing the results of the white matter perfusate test in the first test of the present application.

FIG. 6 is a schematic diagram showing the results of the white matter perfusion test in test II of the present application.

FIG. 7 is a schematic diagram showing the results of the white matter perfusate test in test III of the present application.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings 1 to 7.

The present application takes a preparation method of a human brain model as an example, and the description is given to the present application, and the brain model described in the present application includes but is not limited to a human brain model;

a preparation method of a human brain model comprises the following steps:

step 1: brain model manufactured by using 3D printing technology

To make a biomimetic human brain model, a model was designed that contained a brain shell: the brain internal structure is roughly divided into four parts of tissues, namely Gray matter (Gray matrix), White matter (White matrix), Cerebellum (Cerebellum) and Brainstem (brain), according to different tissues of a human brain, the 3D model of the corresponding structure is designed according to the four parts of tissues, and the 3D models of bleeding points and ischemia points are designed for simulating different health states of the human brain;

step 11: and manufacturing a brain shell model and gray matter, white matter, cerebellum and brainstem models by using a 3D printing technology.

The brain shell model of the resin material is manufactured by using a 3D printing technology: the 3D model of the human skull shell, and the brain inner structure model: 3D models of gray matter, white matter, cerebellum and brainstem.

Step 12: method for manufacturing bleeding point model and ischemia point model by using 3D printing technology

Utilize 3D printing technique preparation diameter to be 2 cm's hollow hemisphere, as bleeding point model and ischemia point model, set up miniature couple on bleeding point model and ischemia point model, convenient dismantlement equipment. The model is shown in fig. 1 and 2.

Step 2: perfusate for configuring internal structure model of brain

Because different tissue Dielectric constants (Dielectric constant) of human brain are different, in order to cover the whole Dielectric constant of brain model to let the manufacture process as convenient as possible, the raw materials that adopt distilled water, oil, coagulant, emulsifier and sodium chloride as the perfusate that this application disposed are finally selected, in order to restrain corruption of each raw materials in this application, make the brain model that this application prepared and obtained have better shelf life, this application has still added the antiseptic.

The perfusate provided by the application comprises: 40-120 mL of distilled water, 10-25 g of coagulant, 0.1-3 g of sodium chloride, 1-60 mL of oil and 10-35 mL of emulsifier.

Wherein the oils are: oils with a dielectric constant of 3-7, in particular vegetable oils, comprising: rapeseed oil and olive oil;

the emulsifier is as follows: O/W type water-oil emulsifier comprises liquid detergent,

the coagulant includes: gelatin and a Geliding powder,

the preservative comprises: n-propanol, sodium azide and p-toluic acid.

The contents of n-propanol, sodium azide and p-toluic acid are respectively as follows: 3-6.5 mL of n-propanol, 0.5-2 g of sodium azide and 0.1-0.2 g of p-toluic acid.

Through continuous tests and preparation of a large number of samples, the ratio of each component of the cerebrospinal fluid perfusate, the gray matter perfusate, the white matter perfusate, the cerebellum perfusate, the brainstem perfusate, the bleeding point perfusate and the ischemia point perfusate is finally obtained, and is shown in table 1.

In the application, the oil is selected from olive oil, the coagulant is selected from gilidine powder, and the preservative is selected from n-propanol, sodium azide and p-toluic acid; the formula of the perfusate is explained.

Table 1 perfusate formula for brain internal structure model

Meanwhile, the preparation method of the perfusate of the internal structure model of the brain is provided according to the formula of the perfusate of the internal structure model of the brain, and the preparation method specifically comprises the following steps:

step 31: weighing the preservative, stirring and heating until the preservative is completely dissolved to obtain a first solution, wherein the heating temperature is 80-90 ℃;

step 32: mixing the first solution with distilled water under a certain temperature condition, adding a coagulant into the first solution, and fully stirring to obtain a mixed solution, wherein the certain temperature condition is 10-30 ℃;

step 33: heating the mixed solution, stirring the mixed solution until the mixed solution is uniform, stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 85-95 ℃ and the mixed solution is transparent;

step 34: cooling to 45-55 ℃, measuring oil, and fully stirring and mixing the oil and the mixed solution obtained in the step (3) until the oil and the mixed solution become uniform to obtain a second solution;

step 35: measuring an emulsifier, adding the emulsifier into the solution II, continuously stirring to obtain an emulsion, adding sodium chloride when the emulsion becomes uniform and almost white, and cooling to 25-35 ℃ to obtain a perfusate;

according to the preparation method of the perfusate of the internal structure model of the brain, the application respectively provides the concrete preparation methods of the perfusate of cerebrospinal fluid, the perfusate of gray matter, the perfusate of white matter, the perfusate of cerebellum, the perfusate of brainstem, the perfusate of bleeding points and the perfusate of ischemia points:

the preparation method of the cerebrospinal fluid perfusate specifically comprises the following steps:

step 311: weighing 1g of sodium azide, 0.1g of p-toluic acid and 4.1mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 312: mixing the solution I with 97.5mL of distilled water at room temperature, and then adding 19.7g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 313: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 314: cooling to about 50 ℃, measuring 2.4mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 315: weighing 15.6mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain emulsion, adding 1.7g of sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain perfusate;

the preparation method of the gray matter perfusate specifically comprises the following steps:

step 321: weighing 1g of sodium azide, 0.1g of p-toluic acid and 4.4mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 322: mixing the solution I with 88.3mL of distilled water at room temperature, and then adding 18.8g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 323: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 324: cooling to about 50 ℃, measuring 11.7mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 325: weighing 17.9mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain emulsion, adding 0.77g of sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain perfusate;

the preparation method of the white matter perfusate specifically comprises the following steps:

step 331: weighing 1.2g of sodium azide, 0.2g of p-toluic acid and 5.1mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 332: mixing the solution I with 65.6mL of distilled water at room temperature, and then adding 16.6g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 333: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 334: cooling to about 50 ℃, measuring 34.4mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 335: weighing 23.6mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain emulsion, adding 0.65 sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain perfusate;

the preparation method of the cerebellum perfusate specifically comprises the following steps:

step 341: weighing 1.1g of sodium azide, 0.1g of p-toluic acid and 4.5mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 342: mixing the solution I with 84.3mL of distilled water at room temperature, and then adding 18.4g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 343: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 344: cooling to about 50 ℃, measuring 15.7mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 345: weighing 18.9mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain an emulsion, and cooling to 35 ℃ to obtain a perfusate when the emulsion becomes uniform and almost white and 1.4g of sodium chloride;

the preparation method of the perfusate for preparing the brainstem specifically comprises the following steps:

step 351: weighing 1.2g of sodium azide, 0.2g of p-toluic acid and 5.1mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 352: mixing the solution I with 62.1mL of distilled water at room temperature, and then adding 16.2g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 353: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 354: cooling to about 50 ℃, measuring 37.9mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 355: weighing 24.5mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain emulsion, adding 0.7g of sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain perfusate;

the preparation method of the perfusion fluid for the bleeding point specifically comprises the following steps:

step 361: weighing 1g of sodium azide, 0.1g of p-toluic acid and 4.3mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 362: mixing the solution I with 91.2mL of distilled water at room temperature, and then adding 19.1g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 363: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 364: cooling to about 50 ℃, measuring 8.8mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 365: weighing 17.2mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain an emulsion, adding 1.5g of sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain a perfusate;

the preparation method of the perfusion fluid for the ischemic point specifically comprises the following steps:

step 371: weighing 1.2g of sodium azide, 0.2g of p-toluic acid and 5.4mL of n-propanol, mixing the sodium azide, the p-toluic acid and the n-propanol in a small beaker, stirring and heating until the sodium azide, the p-toluic acid and the n-propanol are completely dissolved to obtain a first solution, wherein the heating temperature is 85 ℃;

step 372: mixing the solution I with 51.9mL of distilled water at room temperature, and then adding 15.2g of the gerberane powder into the solution I to be fully stirred to obtain a mixed solution;

step 373: covering a layer of plastic film on the beaker, heating the mixed solution by using a magnetic stirrer, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the temperature of the mixed solution reaches 90 ℃ and gradually becomes transparent;

step 374: cooling to about 50 ℃, measuring 48.1mL of olive oil by using a measuring cylinder, and fully stirring and mixing the olive oil and the mixture liquid until the mixture liquid becomes uniform to obtain a solution II;

step 375: weighing 27mL of emulsifier, adding the emulsifier into a beaker, continuously stirring to obtain an emulsion, adding 0.62g of sodium chloride when the emulsion becomes uniform and almost white, and cooling to 35 ℃ to obtain a perfusate;

finally obtaining the perfusate of cerebrospinal fluid, the perfusate of gray matter, the perfusate of white matter, the perfusate of cerebellum, the perfusate of brainstem, the perfusate of bleeding point and the perfusate of ischemia point.

And 4, step 4: brain model perfusion Process

Step 41: brain model perfusion

Performing filling mold manufacturing by using the 3D model obtained in the step 1, placing an ash matter model, a white matter model, a cerebellum model and a brainstem model in a brain outer shell model, performing layer-by-layer perfusion by using each perfusion solution prepared in the step 3, then pressing to form a brain model, and storing the brain model in a refrigerator with the temperature of 4 ℃;

from the mold filling result, the brain model obtained by the method is very close to the shape of the real human brain, all layers are tightly attached and are clear, and the shape and the structure of the human brain are simulated really.

Step 42 of making a brain model with a bleeding point model and an ischemia point model

And (3) respectively filling the prepared perfusion fluid of the bleeding point and the perfusion fluid of the ischemia point into the bleeding point model and the ischemia point model obtained in the step (2), and arranging a micro hook on the bleeding point model and the ischemia point model for the convenience of disassembly and assembly.

Meanwhile, in order to distinguish different states of the human brain conveniently, different colors of the hemisphere models can be used to respectively correspond to the health model, the bleeding point model and the ischemia point model.

And finishing the manufacture of the brain model through the steps.

And (3) measuring the dielectric constant of each part of tissue in the brain model obtained by the steps:

(1) detecting an environment

The test was performed using a high-end vector network analyzer (Keysight, PNAN5222B) and a dielectric constant probe.

(2) Performance analysis of human brain model

The specific test results are shown in fig. 3 and 4, and it can be seen from the results that: compared with the dielectric constants of different tissues and real brain tissues in the human brain model prepared by the application, the dielectric constants and the loss angles are very close to the real result, so that the brain model obtained by the application can be well used for microwave simulation experiments.

The application respectively carries out experimental verification on white matter perfusate, gray matter perfusate, cerebrospinal fluid perfusate, cerebellum perfusate, brainstem perfusate, ischemia point perfusate and hemorrhage point perfusate, and demonstrates the rigor and accuracy of the application.

Test one:

on the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing a white matter perfusate under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the result difference is large under the condition that the olive oil is replaced by the glycerol, the correct electromagnetic property of a human body cannot be correctly reflected, the specific experimental result is shown in figure 5, and the average relative error is 18.6% through quantification.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing a gray matter perfusate under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and can not correctly reflect the correct electromagnetic property of human bodies under the condition that the olive oil is replaced by the glycerol.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing a perfusate of cerebrospinal fluid under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and can not correctly reflect the correct electromagnetic property of human bodies under the condition that the olive oil is replaced by the glycerol.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing a cerebral perfusate under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and can not correctly reflect the correct electromagnetic property of human bodies under the condition that the olive oil is replaced by the glycerol.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing the brain stem perfusate under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and the electromagnetic property of the human body cannot be correctly reflected under the condition that the olive oil is replaced by the glycerol.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, preparing perfusate of a bleeding point under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and the electromagnetic property of the human body cannot be correctly reflected under the condition that the olive oil is replaced by the glycerol.

On the basis of ensuring that other components and contents are unchanged, only replacing the olive oil with glycerol, configuring perfusate of an ischemic point under the condition that the contents are unchanged, finally preparing a brain model by the method provided by the application, and then detecting the dielectric constant;

tests show that the results have large difference and the electromagnetic property of the human body cannot be correctly reflected under the condition that the olive oil is replaced by the glycerol.

And (2) test II:

the white matter perfusate comprises the following components in percentage by weight: 52.4-78.8 mL of distilled water, 27.5-41.3 mL of olive oil, 13.2-20.0 g of geridine powder, 18.8-28.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.4 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 30mL, the components of the Geliding powder are changed into 30g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

the measured results are shown in fig. 6, and the average relative error is 25.4% by quantification, and the results are greatly different.

The content of each component in the perfusion liquid of the gray matter is respectively as follows: 70.6-106.0 mL of distilled water, 9.3-14.1 mL of olive oil, 15.0-22.6 g of geridine powder, 14.3-21.5 mL of emulsifier, 3.5-5.3 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.6-0.9 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 50mL, the components of the Geliding powder are changed into 35g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

The cerebrospinal fluid perfusate comprises the following components in percentage by weight: 78.0-117.0 mL of distilled water, 1.9-2.9 mL of olive oil, 15.7-23.7 g of geridine powder, 12.4-18.8 mL of emulsifier, 3.2-5.0 mL of n-propanol, 0.8-1.2 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.3-2.1 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the distilled water is changed into 60mL, the gericut beetle powder is changed into 35g, then the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

The cerebellum perfusate comprises the following components in percentage by weight: 67.4-101.2 mL of distilled water, 12.5-8.9 mL of olive oil, 14.7-22.1 g of geridine powder, 15.1-22.7 mL of emulsifier, 3.6-5.4 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.7 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 45mL, the components of the Geliding powder are changed into 35g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

The perfusate for brainstem comprises the following components in percentage by weight: 49.6-74.6 mL of distilled water, 30.3-45.5 mL of olive oil, 12.9-19.5 g of geridine powder, 19.6-29.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.9 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 30mL, the components of the Geliding powder are changed into 30g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

The bleeding point perfusate comprises the following components in percentage by weight: 72.9-109.5 mL of distilled water, 7.0-10.6 mL of olive oil, 15.2-23 g of geridine powder, 13.7-20.7 mL of emulsifier, 3.4-5.2 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 50mL, the components of the Geliding powder are changed into 35g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

The perfusate of the ischemia point comprises the following components in percentage by weight: 41.5-62.3 mL of distilled water, 38.4-57.8 mL of olive oil, 12.1-18.3 g of geridine powder, 21.6-32.4 mL of emulsifier, 4.3-6.5 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.4-0.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the components of distilled water are changed into 30mL, the components of the Geliding powder are changed into 30g, the brain model is finally manufactured by the method provided by the application, and then the dielectric constant is detected;

experiments show that the result has larger difference compared with the standard value and can not correctly reflect the electromagnetic property of the human body.

And (3) test III:

the white matter perfusate comprises the following components in percentage by weight: 52.4-78.8 mL of distilled water, 27.5-41.3 mL of olive oil, 13.2-20.0 g of geridine powder, 18.8-28.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.4 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

I.e., "oil low-giow" means: minimum 27.5mL of olive oil, minimum 13.2g of gilidine powder, "oil low-giigh" means: minimum 27.5mL of olive oil, maximum 20.0g of gilidine powder, "oil high-gilow" means: maximum of 41.3mL olive oil, minimum of 13.2g gillidin powder, "oil high-gillidin" means maximum of 41.3mL olive oil, maximum of 20.0g gillidin powder.

The method comprises the steps of finally manufacturing a brain model by the method provided by the application, and then detecting the dielectric constant;

the actual measurement result is shown in fig. 7, and through quantification, when the minimum value of the olive oil and the minimum value of the gilding powder are selected for configuration, the average relative error is 9.25%; when the minimum value of the olive oil and the maximum value of the gilding powder are selected for configuration, the average relative error is 4.23 percent, when the maximum value of the olive oil and the minimum value of the gilding powder are selected for configuration, the average relative error is 3.96 percent, and when the maximum value of the olive oil and the maximum value of the gilding powder are selected for configuration, the average relative error is 8.52 percent.

From the above results, it can be seen that within the range provided by the present application, the relative error is within 10%, which proves that the formula effect is good in robustness.

The content of each component in the perfusion liquid of the gray matter is respectively as follows: 70.6-106.0 mL of distilled water, 9.3-14.1 mL of olive oil, 15.0-22.6 g of geridine powder, 14.3-21.5 mL of emulsifier, 3.5-5.3 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.6-0.9 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

The cerebrospinal fluid perfusate comprises the following components in percentage by weight: 78.0-117.0 mL of distilled water, 1.9-2.9 mL of olive oil, 15.7-23.7 g of geridine powder, 12.4-18.8 mL of emulsifier, 3.2-5.0 mL of n-propanol, 0.8-1.2 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.3-2.1 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

The cerebellum perfusate comprises the following components in percentage by weight: 67.4-101.2 mL of distilled water, 12.5-8.9 mL of olive oil, 14.7-22.1 g of geridine powder, 15.1-22.7 mL of emulsifier, 3.6-5.4 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.7 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

The perfusate for brainstem comprises the following components in percentage by weight: 49.6-74.6 mL of distilled water, 30.3-45.5 mL of olive oil, 12.9-19.5 g of geridine powder, 19.6-29.4 mL of emulsifier, 4.0-6.2 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.5-0.9 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

The perfusate of the ischemia point comprises the following components in percentage by weight: 41.5-62.3 mL of distilled water, 38.4-57.8 mL of olive oil, 12.1-18.3 g of geridine powder, 21.6-32.4 mL of emulsifier, 4.3-6.5 mL of n-propanol, 0.9-1.5 g of sodium azide, 0.1-0.2 g of p-toluic acid and 0.4-0.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

The bleeding point perfusate comprises the following components in percentage by weight: 72.9-109.5 mL of distilled water, 7.0-10.6 mL of olive oil, 15.2-23 g of geridine powder, 13.7-20.7 mL of emulsifier, 3.4-5.2 mL of n-propanol, 0.8-1.3 g of sodium azide, 0.1-0.2 g of p-toluic acid and 1.1-1.8 g of sodium chloride.

On the basis of ensuring that other components and contents are not changed, the highest value and the lowest value of the olive oil and the gerbera powder are respectively selected for configuration, the brain model finally manufactured by the method provided by the application is detected, and therefore the correctness of the formula is verified.

The experimental quantification shows that the result has smaller difference compared with the standard value, and can correctly reflect the electromagnetic property of the human body.

Those not described in detail in this specification are within the skill of the art.

Claims (20)

1. The perfusate is characterized in that the proportions of the components in the perfusate comprise: 40-120 mL of distilled water, 10-25 g of coagulant, 0.1-3 g of sodium chloride, 1-60 mL of oil and 10-35 mL of emulsifier.

2. The perfusate of claim 1, wherein the oil has a dielectric constant of 3 to 7.

3. The perfusate of claim 1, wherein the coagulant comprises: gelatin and/or gilidine powder.

4. The perfusate of claim 1, wherein the perfusate further comprises: and (4) a preservative.

5. The perfusate of claim 4, wherein the preservatives comprise: n-propanol, sodium azide and p-toluic acid.

6. Use of the perfusate of any one of claims 1 to 5 for the preparation of a brain model.

7. A perfusate for use in a model of an internal structure of the brain, comprising: cerebrospinal fluid perfusate, gray matter perfusate, white matter perfusate, cerebellum perfusate, brainstem perfusate, bleeding point perfusate and ischemia point perfusate.

8. The perfusate for the brain internal structure model according to claim 7, wherein the perfusate for cerebrospinal fluid comprises the following components in proportion: 78-117 mL of distilled water, 1.9-2.9 mL of olive oil, 15.7-23.7 g of Geliding powder, 12.4-18.8 mL of emulsifier and 1.3-2.1 g of sodium chloride.

9. The perfusate for the brain internal structure model according to claim 7, wherein the grey matter perfusate comprises the following components in proportion: 70.6-106.0 mL of distilled water, 9.3-14.1 mL of olive oil, 15.0-22.6 g of geridine powder, 14.3-21.5 mL of emulsifier and 0.6-0.9 g of sodium chloride.

10. The perfusate of the brain internal structure model according to claim 7, wherein the ratio of the components in the perfusate of white matter is: 52.4-78.8 mL of distilled water, 27.5-41.3 mL of olive oil, 13.2-20.0 g of Geliding powder, 18.8-28.4 mL of emulsifier and 0.5-0.8 g of sodium chloride.

11. The perfusate of the brain internal structure model of claim 7, wherein the perfusate of the cerebellum comprises the following components in proportion: 67.4-101.2 mL of distilled water, 12.5-18.9 mL of olive oil, 14.7-22.1 g of geridine powder, 15.1-22.7 mL of emulsifier and 1.1-1.7 g of sodium chloride.

12. The perfusate of the brain internal structure model of claim 7, wherein the perfusate of the brain stem comprises the following components in proportion: 49.6-74.6 mL of distilled water, 30.3-45.5 mL of olive oil, 12.9-19.5 g of geridine powder, 19.6-29.4 mL of emulsifier and 0.5-0.9 g of sodium chloride.

13. The perfusate for the brain internal structure model according to claim 7, wherein the ratio of the components in the perfusion fluid for the bleeding point is as follows: 72.9-109.5 mL of distilled water, 7.0-10.6 mL of olive oil, 15.2-23 g of Geliding powder, 13.7-20.7 mL of emulsifier and 1.1-1.8 g of sodium chloride.

14. The perfusate of the brain internal structure model of claim 7, wherein the perfusate of the ischemia site comprises the following components in proportion: 41.5-62.3 mL of distilled water, 38.4-57.8 mL of olive oil, 12.1-18.3 g of geridine powder, 21.6-32.4 mL of emulsifier and 0.4-0.8 g of sodium chloride.

15. The method for preparing the perfusion fluid as claimed in any one of claims 1 to 5, which comprises the following steps:

step 1: weighing a certain amount of preservative, stirring and heating until the preservative is completely dissolved to obtain a solution I;

step 2: mixing the solution I with distilled water, and then adding a coagulant into the solution I to be fully stirred to obtain a mixed solution;

and step 3: heating the mixed solution, stirring the mixed solution until the mixed solution is uniform, and stopping heating and removing surface bubbles when the mixed solution becomes transparent;

and 4, step 4: cooling, measuring oil, and fully stirring and mixing the oil and the mixed solution obtained in the step (3) until the oil and the mixed solution become uniform to obtain a solution II;

and 5: and measuring an emulsifier, adding the emulsifier into the solution II, continuously stirring to obtain an emulsion, adding sodium chloride when the emulsion becomes uniform and white, and cooling to obtain a perfusate.

16. A brain model comprising the perfusate of any one of claims 1 to 5.

17. The brain model of claim 16, wherein the brain model comprises: a healthy brain model, a brain model with a bleeding point model, or a brain model with an ischemia point model.

18. The brain model of claim 17, wherein the bleeding or ischemic point model is a hemisphere of 1-3 cm diameter.

19. The brain model of claim 18, wherein a microhook is provided on the bleeding or ischemic point model.

20. A method for preparing a brain model is characterized by comprising the following steps:

s1, manufacturing a brain shell model and a brain internal structure model of a resin material by using a 3D printing technology;

s2, adopting the perfusion fluid of any one of claims 1 to 5 to configure a brain internal structure model;

and S3, performing layered perfusion on the shell model and the internal brain structure model of the brain model by using the perfusate obtained in the step S2, and pressing to obtain the brain model.

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