Phantom preparation method

[0016] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments It is a part of embodiments of the present invention, but not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0017] It should be understood that the term "and/or" used herein is only an association relationship describing associated objects, indicating that there may be three relationships, for example, A and/or B, which may mean that A exists alone, and A and B exist simultaneously. B, there are three situations of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

[0018] Depending on the context, the word "if" as used herein may be interpreted as "at" or "when" or "in response to determining" or "in response to detecting". Similarly, depending on the context, the phrases "if determined" or "if detected (the stated condition or event)" could be interpreted as "when determined" or "in response to the determination" or "when detected (the stated condition or event) )" or "in response to detection of (a stated condition or event)".

[0019] figure 1 The flow chart of the phantom preparation method provided by Embodiment 1 of the present invention, such as figure 1 As shown, the phantom preparation method provided in this embodiment includes the following steps.

[0020] Step 101, preparing at least one polyvinyl alcohol aqueous solution containing scatterers and/or at least one polyacrylamide hydrogel containing scatterers.

[0021] In this embodiment, different types of polyvinyl alcohol aqueous solutions refer to different concentrations of polyvinyl alcohol in the aqueous solution. Different types of polyacrylamide hydrogels mean that the strength and elasticity of polyacrylamide hydrogels are different.

[0022] Specifically, in this embodiment, when preparing at least one polyvinyl alcohol aqueous solution containing scatterers, scatterers and polyvinyl alcohol can be added to water, and different types of polyvinyl alcohol containing scatterers can be prepared according to the concentration of polyvinyl alcohol in the aqueous solution. Aqueous solution of polyvinyl alcohol.

[0023] In this embodiment, the polyvinyl alcohol aqueous solution contains scatterers, and the scatterers can be micron-sized graphite, cellulose, silicon dioxide, or other scatterers, which are not limited in this embodiment. When preparing an aqueous solution of polyvinyl alcohol containing scatterers, the scatterers can be directly added to the aqueous solution of polyvinyl alcohol.

[0024] Among them, the function of the scatterers is that the manufactured phantom can be used in ultrasonic imaging.

[0025] Specifically, in this embodiment, when preparing at least one polyacrylamide hydrogel containing scatterers, polyacrylamide containing different molecular weight grades, scatterers, crosslinking agents, catalysts and oxidants are polymerized in water, Polyvinylamide hydrogels are formed. Among them, different molecular weight grades can be divided into high molecular weight grades, middle molecular weight grades and low molecular weight grades. When preparing different types of polyvinylamide hydrogels, they are prepared according to the mass ratio of polyacrylamide of different molecular weight grades. The higher the mass ratio of high-molecular-weight grade polyvinylamide, the greater the elasticity of the prepared polyvinylamide hydrogel. The less elastic the glue is. The specific mass ratio can be illustrated as follows: first set the molecular weight of a single polyacrylamide system, such as setting a polyacrylamide with a molecular weight of 25 million as the standard for the average molecular weight of the mixed polyacrylamide, and then according to the high and medium , three grades lower, select three grades of polyacrylamide with molecular weight and mix them in mass proportion, so that the average molecular weight of polyacrylamide after mixing is roughly equal to the set molecular weight of 25 million polyacrylamide. To improve the elasticity and strength of polyacrylamide hydrogel, it is necessary to increase the mass ratio of high-molecular-weight polyacrylamide; The mass ratio of acrylamide, the principle of setting the mass ratio of polyacrylamide with different molecular weight grades is the principle of the nearest half. %, the mass ratio of polyacrylamide with a molecular weight of 36 million accounts for 40.625%, and the mass ratio of polyacrylamide with a molecular weight of 4 million accounts for 9.375%.

[0026] Wherein, the crosslinking agent may be methylenebisacrylamide, the catalyst may be tetramethylethylenediamine, abbreviated as TEMED, and the oxidizing agent may be ammonium persulfate.

[0027] In this embodiment, when preparing at least one polyacrylamide hydrogel containing scatterers, different types of polyacrylamide hydrogels containing scatterers can also be prepared by adjusting the concentration of polyacrylamide in the aqueous solution, To prepare phantoms of different elasticity for use in ultrasound elastography.

[0028] In this embodiment, the polyacrylamide hydrogel contains scatterers, and the scatterers may be micron-sized graphite, cellulose, silicon dioxide, or other scatterers, which are not limited in this embodiment. When preparing the polyvinylamide hydrogel containing scatterers, the scatterers can be directly added to the aqueous solution of polyvinylamide, and polymerized with a crosslinking agent, a catalyst and an oxidant in the aqueous solution.

[0029] Step 102, placing polyvinyl alcohol aqueous solution and/or polyacrylamide hydrogel in a mold to form a phantom.

[0030] In this embodiment, placing the polyvinyl alcohol aqueous solution in the mold to form a phantom may be: placing the polyvinyl alcohol aqueous solution in the mold, and using the repeated freezing and thawing method to make the polyvinyl alcohol aqueous solution form a polyvinyl alcohol hydrogel, Vinyl alcohol hydrogel was the formed phantom.

[0031] Alternatively, in this embodiment, the polyacrylamide hydrogel is placed in a mold to form a phantom, specifically: the polyacrylamide hydrogel, curing agent, initiator, catalyst and crosslinking agent are placed in the corresponding water The polymerization reaction is carried out in the mold to form a phantom.

[0032] Alternatively, in this embodiment, polyvinyl alcohol aqueous solution and polyacrylamide hydrogel are placed in a mold to form a phantom. Specifically, polyvinyl alcohol aqueous solution and polyacrylamide hydrogel are placed in a mold to form a non-uniform phantom, which is composed of a phantom formed by polyvinyl alcohol aqueous solution and a phantom formed by polyacrylamide hydrogel.

[0033] In this embodiment, the elasticity of each phantom formed is different. Used in ultrasound elastography, each phantom simulates the liver at different stages. For example, the most elastic phantom simulates a healthy liver, while the less elastic phantom represents a fibrotic liver.

[0034] The phantom preparation method provided in this embodiment is prepared by preparing at least one polyvinyl alcohol aqueous solution containing scatterers and/or at least one polyacrylamide hydrogel containing scatterers; mixing polyvinyl alcohol aqueous solution and/or polypropylene The amide hydrogel is placed in a mold to form a phantom. Since the polyvinyl alcohol hydrogel and/or polyacrylamide hydrogel formed by polyvinyl alcohol aqueous solution has the characteristics of high strength, wide range of elastic changes, and stable properties during use and storage, so polyvinyl alcohol hydrogel The phantom formed by glue and/or the phantom made by polyacrylamide hydrogel through polymerization reaction with curing agent also has the characteristics of high strength and strong property stability during storage and use.

[0035]Embodiment 2 of the present invention also provides a phantom preparation method. The phantom preparation method provided in Embodiment 2 of the present invention has the same steps as the phantom preparation method provided in Embodiment 1 of the present invention, and steps 101-102 are performed. For further refinement, the phantom preparation method provided in this embodiment includes the following steps and features.

[0036] Step 201, preparing at least one polyvinyl alcohol aqueous solution containing scatterers and/or at least one polyacrylamide hydrogel containing scatterers.

[0037] Further, in this embodiment, at least one polyvinyl alcohol aqueous solution containing scatterers is prepared, specifically including:

[0038] Add scatterers and polyvinyl alcohol into water, and prepare different kinds of polyvinyl alcohol aqueous solutions containing scatterers according to the concentration of polyvinyl alcohol in the aqueous solution.

[0039] Further, in this embodiment, at least one polyacrylamide hydrogel containing scatterers is prepared, specifically including:

[0040] Polyacrylamide containing different molecular weight grades, scatterers, crosslinking agents, catalysts and oxidants are polymerized in water, and different types of polyacrylamide hydrogels are prepared according to the mass ratio of polyacrylamide with different molecular weight grades .

[0041] Specifically, in this example, polyacrylamide containing different molecular weight grades is polymerized with scatters, crosslinking agents, catalysts and oxidants in water according to different mass ratios, and the elasticity of the polyacrylamide hydrogel formed is Different, that is to form different kinds of polyacrylamide hydrogels. When the mass ratio of polyacrylamide with higher molecular weight grade among polyacrylamides containing different molecular weight grades is higher, the elasticity of the formed polyacrylamide hydrogel is greater. Conversely, when the mass ratio of polyacrylamide of lower molecular weight grade among polyacrylamides containing different molecular weight grades is higher, the elasticity of the formed polyacrylamide hydrogel is smaller.

[0042] Step 202, placing polyvinyl alcohol aqueous solution and/or polyacrylamide hydrogel in a mold to form a phantom.

[0043] Further, the polyvinyl alcohol aqueous solution is placed in the mold to form a phantom, which specifically includes:

[0044] The polyvinyl alcohol aqueous solution is placed in the mold, and the polyvinyl alcohol aqueous solution is formed into a polyvinyl alcohol hydrogel by a repeated freezing and thawing method, and the polyvinyl alcohol hydrogel is a formed phantom.

[0045] Specifically, in this embodiment, a polyvinyl alcohol hydrogel can be prepared from a polyvinyl alcohol aqueous solution by repeated freezing and thawing. Wherein the temperature of freezing can be minus 20 degrees, and the temperature of melting can be minus 20 degrees. Among them, different types of polyvinyl alcohol hydrogels can be prepared according to the number of freezing and thawing cycles, the greater the number of freezing and thawing cycles, the greater the elasticity of the prepared polyvinyl alcohol hydrogel. Different types of polyvinyl alcohol hydrogels can also be prepared according to the concentration of polyvinyl alcohol in the polyvinyl alcohol aqueous solution. The greater the concentration of polyvinyl alcohol, the greater the elasticity of the prepared polyvinyl alcohol hydrogel. It can be understood that different types of polyvinyl alcohol hydrogels can be prepared by comprehensively considering the number of cycles of freezing and thawing and the concentration of polyvinyl alcohol.

[0046] In this embodiment, the polyvinyl alcohol hydrogel has the characteristics of good lubrication performance, sufficient shock absorption capacity, good biocompatibility, high elasticity, high strength, and can be firmly connected with the host bone.

[0047] Further, the polyacrylamide hydrogel is placed in the mold to form a phantom, which specifically includes:

[0048] Polyacrylamide hydrogel is polymerized with curing agent, initiator, catalyst and crosslinking agent in a corresponding mold filled with water to form a phantom.

[0049] Wherein, the curing agent can be a kind of substance or mixture that promotes or controls the curing reaction. In this embodiment, the curing agent may be aliphatic amines or aromatic amines. For example, it can be aminoethylpiperazine, m-xylylenediamine or a mixture of the two.

[0050] Preferably, in this embodiment, the curing agent includes: aminoethylpiperazine and m-xylylenediamine.

[0051] The initiator can be ammonium persulfate, the catalyst can be TEMED, and the crosslinking agent can be methylenebisacrylamide.

[0052] In this embodiment, each kind of polyacrylamide hydrogel containing scatterers and curing agent, initiator, catalyst and crosslinking agent carry out polymerization reaction in the corresponding mold with water, which can be carried out at normal temperature, and the mixing The solution was stirred.

[0053] Further, placing the polyvinyl alcohol aqueous solution and/or the polyacrylamide hydrogel in the mold to form the phantom also includes:

[0054] At least one other phantom is fabricated on the periphery of at least one phantom to form a non-uniform phantom.

[0055] Further, in this embodiment, at least another phantom is prepared on the periphery of at least one phantom to form a non-uniform phantom, specifically including:

[0056] According to the positional relationship of various phantoms in the non-uniform phantom, put the phantom near the inside into the corresponding mold, and prepare the phantom near the outside including the phantom near the inside in the mold to form the non-uniform phantom.

[0057] Specifically, in this embodiment, the non-uniform phantom may include various phantoms, and the positional relationships of the various phantoms are varied. figure 2 It is a schematic diagram of the first structure of the phantom formed in the phantom preparation method provided in Example 2 of the present invention, image 3 It is a schematic diagram of the second structure of the phantom formed in the phantom preparation method provided in Example 2 of the present invention, figure 2 and image 3 The schematic diagrams shown represent an example of the formed non-uniform phantom, and the structure of the non-uniform phantom provided in this embodiment is not limited to figure 2 and image 3 situation shown. figure 2 Three types of phantoms are included in the non-uniform phantoms shown. The third phantom 23 on the outermost side covers the first phantom 21 and the second phantom 22 near the inner side. image 3 Three phantoms are also included. The outermost third phantom 23 covers the inner second phantom 22 , and the second phantom 22 covers the innermost first phantom 21 .

[0058] In this embodiment, the phantom near the inner side is prepared first, and then according to the positional relationship of various phantoms of the non-uniform phantom, the position of the phantom near the inner side in the phantom near the outer side is determined, and the phantom near the inner side is The mold is placed in a preset position in the mold forming the phantom near the outside, and then the preparation solution for forming the phantom near the outside is poured into the mold, and a polymerization reaction is carried out to form a phantom near the outside, while a phantom near the inside The phantom is fixed at the preset position near the outer phantom. Regardless of the types of phantoms included in the non-uniform phantom to be prepared, the principle of preparation is to prepare phantoms near the inner side first, and then prepare phantoms near the outer side until the entire non-uniform phantom is prepared.

[0059] In this embodiment, a non-uniform phantom is prepared for ultrasound elastography, which can simulate a diseased liver. For example, the phantom at the outermost periphery has the highest elasticity to simulate a healthy liver. The phantoms closer to the inside, covered by the outermost phantom, became less elastic to simulate a lesion within a healthy liver.

[0060] Further, in this embodiment, the degassing condition for forming the phantom is degassing at a temperature of 110 degrees for two hours.

[0061] Specifically, in this embodiment, before the polyvinyl alcohol aqueous solution containing scatterers is repeatedly frozen and thawed, a degassing treatment is performed, and a vacuum pump is used to degas the polyvinyl alcohol aqueous solution containing scatterers, and the degassing temperature is 110 degrees , and then repeatedly freezing and thawing the polyvinyl alcohol aqueous solution containing scatterers can effectively reduce the air bubbles in the formed polyvinyl alcohol hydrogel, thereby making the formed ultrasonic elastography phantom more uniform.

[0062] Alternatively, in this embodiment, each polyacrylamide hydrogel containing scatterers and a curing agent, an initiator, a catalyst and a crosslinking agent are polymerized in a corresponding phantom mold with water, using The vacuum pump degasses the mixed solution, and the degassing temperature is 110 degrees, which can effectively reduce the air bubbles in the formed ultrasonic elastography phantom and make the formed ultrasonic elastography phantom more uniform.

[0063] It can be understood that the degassing condition when preparing the phantom near the outside is also degassing at a temperature of 110 degrees for two hours, so as to effectively reduce the air bubbles in the formed non-uniform phantom and make the formed non-uniform phantom more uniform.

[0064] The method for preparing a phantom provided in this embodiment, placing polyvinyl alcohol aqueous solution and/or polyacrylamide hydrogel in a mold to form a phantom includes: placing polyvinyl alcohol aqueous solution in a mold, and using the repeated freezing and thawing method to make the phantom Polyvinyl alcohol aqueous solution forms polyvinyl alcohol hydrogel, and polyvinyl alcohol hydrogel is the phantom formed, or polyacrylamide hydrogel is mixed with curing agent, initiator, catalyst and crosslinking agent in water A polymerization reaction is carried out in the corresponding mold to form a phantom. Alternatively, at least one other phantom is prepared on the periphery of at least one phantom to form a non-uniform phantom. On the basis of forming different phantoms, non-uniform phantoms can be formed, which can be used in ultrasonic elastography, and can realize the simulation of livers in different lesion stages, and are more suitable for clinical practice.