Head phantom for calibration of in-vivo dosimetry devices for cranial irradiation and method of manufacture

Abstract

The present application relates to a kind of skull model and preparation method for head inside irradiation living body measurement device calibration, wherein the skull model includes skull, epidermis layer and radioactive source;The radioactive source is arranged on the surface of the skull, and is located on the skull corresponding parietal bone and frontal bone position;The epidermis layer is fixed on the surface of the skull by pouring, and is tissue equivalent material.The present application sets up radioactive source on the surface of the skull, and uses tissue equivalent material as epidermis layer, to form skull model, the model can simulate the deposition in the skull after human body is taken into parent bone nature nuclide, i.e.as the real human body nuclide intake amount according to the amount of radioactive source setting, so as to more accurately calibrate the scale of head inside irradiation living body measurement device, to improve the measurement precision of human body nuclide activity.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of internal irradiation in vivo measurement, and particularly relates to a head model for calibration of a skull internal irradiation in vivo measurement device and a manufacturing method. BACKGROUND

[0002] In the whole industry chain process of the nuclear industry, radionuclides may enter the body through ingestion, inhalation, wound penetration and other ways, and cause internal irradiation to the human body, which is more serious than external irradiation of the same level. Therefore, it is particularly important to accurately evaluate and calculate internal irradiation. At present, internal irradiation dose estimation is mainly based on the mathematical model of international organizations such as ICRU and NCRP, and the calculation method is relatively fixed. The main source of uncertainty in the process of internal irradiation dose evaluation is the determination of the human body nuclide intake. The intake is mainly obtained by interpreting the measurement results of the internal irradiation in vivo measurement device. Therefore, it is necessary to accurately calibrate the internal irradiation in vivo measurement device. Therefore, a head model that can simulate the actual nuclide deposition is needed to accurately calibrate the skull internal irradiation in vivo measurement device, so as to improve the measurement accuracy of the human body nuclide activity. At present, there is no such model in China, and the skull internal irradiation in vivo measurement device in China lacks corresponding calibration equipment, and the measurement results cannot be accurately interpreted. The above problems need to be solved. SUMMARY

[0003] The present application discloses a head model for calibration of a skull internal irradiation in vivo measurement device and a manufacturing method, which aims to solve the technical problems existing in the prior art.

[0004] The present application adopts the following technical scheme:

[0005] The present application provides a head model for calibration of a skull internal irradiation in vivo measurement device, which comprises a skull, an epidermal layer and a radioactive source; the radioactive source is arranged on the surface of the skull and located at the positions of the parietal bone and the frontal bone on the skull; the epidermal layer is fixed on the surface of the skull by pouring and is a tissue equivalent material.

[0006] In the head model for calibration of a skull internal irradiation in vivo measurement device, the skull comprises a skull upper half structure and a skull lower half structure; the skull upper half structure comprises a parietal bone part and a frontal bone part; the skull lower half structure is the remaining part of the skull except the parietal bone part and the frontal bone part; the epidermal layer comprises an upper half epidermal layer and a lower half epidermal layer which are adhesively connected; the upper half epidermal layer is arranged on the surface of the skull upper half structure; and the lower half epidermal layer is arranged on the surface of the skull lower half structure.

[0007] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, the radioactive source is a point radioactive source, and a plurality of the point radioactive sources are uniformly distributed on the surface of the skull corresponding to the parietal bone and frontal bone positions.

[0008] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, the radioactive source is arranged on the surface of the skull corresponding to the parietal bone and frontal bone positions by a positioning sheet; the positioning sheet comprises a lofting sheet and a cover sheet; the lofting sheet is the same shape as the developed pattern of the surface of the skull corresponding to the parietal bone and frontal bone positions, and the radioactive source is arranged on the lofting sheet; the cover sheet covers the radioactive source and forms a sealed space with the edge of the lofting sheet.

[0009] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, the lofting sheet is a water-absorbing sheet.

[0010] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, a marking structure is further included; the marking structure is arranged on the surface of the skin layer for positioning during calibration.

[0011] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, the skin layer is a structure of elastic material.

[0012] In the skull model for calibration of the in-vivo measurement device for intracranial irradiation, the skull is a structure of resin material.

[0013] In a second aspect, the present application further provides a preparation method of the skull model as described above, comprising the following steps:

[0014] obtaining a digital skull model;

[0015] forming a skull model by three-dimensional printing of the digital skull model;

[0016] manufacturing a skull mold by the skull model;

[0017] injecting a skull material into the skull mold, demolding to obtain a skull;

[0018] arranging a radioactive source on the surface of the skull;

[0019] placing the skull in a skin forming mold, injecting a tissue-equivalent material, and demolding to obtain a skull model.

[0020] In a third aspect, the present application further provides a preparation method of the skull model as described above, comprising the following steps:

[0021] dividing the digital skull model into an upper half of the skull including the parietal bone and frontal bone, and a lower half of the skull.

[0022] forming a skull upper half model and a skull lower half model by three-dimensional printing of the skull upper half and the skull lower half respectively;

[0023] manufacturing a skull upper half mold and a skull lower half mold respectively with the skull upper half model and the skull lower half model;

[0024] obtaining a skull upper half structure and a skull lower half structure by injecting resin material into the skull upper half mold and the skull lower half mold and demolding;

[0025] providing a radiation source on the surface of the skull upper half structure;

[0026] placing the skull upper half structure and the skull lower half structure in corresponding scalp forming molds respectively;

[0027] injecting tissue equivalent material into the scalp forming molds, demolding, and obtaining a skull upper half structure with an upper half epidermis layer and a skull lower half structure with a lower half epidermis layer;

[0028] splicing the skull upper half structure and the skull lower half structure and bonding the upper half epidermis layer and the lower half epidermis layer, and obtaining a skull model.

[0029] The technical solution adopted by the present application can achieve the following beneficial effects:

[0030] The present application mainly provides a skull model for calibration of an in-vivo measurement device for skull internal irradiation, which is based on setting a radiation source on the surface of the skull and using tissue equivalent material as the epidermis layer to form a skull model. The model can simulate the deposition of a bone-seeking radionuclide in the skull after being taken into the human body, i.e. the amount of radionuclide taken into the human body according to the amount of the set radiation source, so that the in-vivo measurement device for skull internal irradiation can be more accurately calibrated, thereby improving the measurement accuracy of the radionuclide activity in the human body. BRIEF DESCRIPTION OF DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description, which constitutes a part of the present application. The schematic embodiments of the present application and their description and explanation do not constitute an improper limitation on the present application. In the drawings:

[0032] Figure 1 It is a structure schematic view of a skull model for calibration of an in-vivo measurement device for skull internal irradiation of the present application;

[0033] Figure 2 It is a structure schematic view of a skull of the present application;

[0034] Figure 3 Fig. 1 is a front view of the upper half of the skull structure of the present application;

[0035] Figure 4 Fig. 2 is a top view of the upper half of the skull structure of the present application;

[0036] Figure 5 Fig. 3 is a partial cross-sectional view of the upper half of the skull structure of the present application;

[0037] Figure 6 Fig. 4 is another partial cross-sectional view of the upper half of the skull structure of the present application.

[0038] BRIEF DESCRIPTION OF THE DRAWINGS

[0039] 1. skull; 11. upper half of the skull structure; 111. parietal bone part; 112. frontal bone part; 12. lower half of the skull structure; 2. epidermis layer; 21. upper half of the epidermis layer; 22. lower half of the epidermis layer; 3. radioactive source; 4. positioning sheet; 41. radiographic sheet; 42. covering sheet; 43. hot melt adhesive sheet; 5. marking structure. DETAILED DESCRIPTION

[0040] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in connection with specific embodiments of the present application and corresponding drawings. In the description of the present application, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise.

[0041] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can also be magnetic connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances. In addition, in the description of the present application, the terms "first", "second" and the like are only used to distinguish the description and cannot be understood as indicating or implying relative importance. In the description of the present application, the meaning of "multiple" is at least two, for example, two, three or more, etc., unless otherwise explicitly specified and limited.

[0042] Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0043] To solve the problems in the prior art, the application provides a skull model for calibration of an in-vivo measurement device for internal irradiation of a skull and a manufacturing method.

[0044] As shown in Figure 1 and Figure 2 , a skull model for calibration of an in-vivo measurement device for internal irradiation of a skull comprises a skull 1, an epidermal layer 2 and a radioactive source 3; the radioactive source 3 is arranged on the surface of the skull 1 and located at a position corresponding to the parietal bone and the frontal bone on the skull 1; the epidermal layer 2 is fixed on the surface of the skull 1 by pouring and is a tissue-equivalent material.

[0045] The skull model for calibration of the in-vivo measurement device for internal irradiation of the skull in the application is based on arranging the radioactive source 3 on the surface of the skull 1 and using a tissue-equivalent material as the epidermal layer 2 to form the skull model, and the amount of the radioactive source 3 is used to obtain the intake amount of the human body nuclide (i.e. the amount of the radioactive source 3 is used as the retention amount, and then the intake amount of the human body nuclide is calculated), so that the model can simulate the deposition of the human body after the intake of the bone-seeking nuclide in the skull, thereby more accurately calibrating the in-vivo measurement device for internal irradiation of the skull, and improving the measurement accuracy of the nuclide activity in the human body.

[0046] In some preferred embodiments, as shown in Figures 2-4 , the skull 1 comprises a skull upper half structure 11 and a skull lower half structure 12; the skull upper half structure 11 comprises a parietal bone part 111 and a frontal bone part 112; the skull lower half structure 12 is the remaining part of the skull 1 except the parietal bone part 111 and the frontal bone part 112; the epidermal layer 2 comprises an upper half epidermal layer 21 and a lower half epidermal layer 22 which are adhesively connected; the upper half epidermal layer 21 is arranged on the surface of the skull upper half structure 11; the lower half epidermal layer 22 is arranged on the surface of the skull lower half structure 12; based on arranging the skull 1 to comprise the skull upper half structure 11 and the skull lower half structure 12, only the radioactive source 3 needs to be arranged on the surface of the skull upper half structure 11, and the part where the radioactive source 3 needs to be arranged is separated out, thereby avoiding misoperation of arranging the radioactive source at other positions, and reducing the structure volume where the radioactive source 3 is arranged, improving the efficiency during manufacturing, and not affecting the simulation accuracy.

[0047] In some preferred embodiments, the radioactive source 3 is a point-like radioactive source, and there are a plurality of point-like radioactive sources which are uniformly distributed on the surface of the skull 1 at the positions corresponding to the parietal bone and the frontal bone; based on arranging the radioactive source 3 as a point-like structure, the amount of the radioactive source 3 can be determined based on the number of the point-like structures, and then the intake amount of the human body nuclide is determined, thereby achieving a better simulation effect of the actual intake of the radioactive nuclide.

[0048] In some preferred embodiments, as shown in Figure 5As shown, the radioactive source 3 is arranged on the skull 1 through the positioning sheet 4 corresponding to the surface of the parietal bone and frontal bone position; the positioning sheet 4 includes the lofting sheet 41 and the cover sheet 42; the lofting sheet 41 is the same as the unfolded figure of the surface of the skull 1 corresponding to the parietal bone and frontal bone position, and optionally, the unfolded figure can be obtained by unfolding the region of the surface of the skull 1 corresponding to the parietal bone and frontal bone position in the digital model of the skull 1 through zbrush or SolidWorks software, and preferably, when the skull 1 includes the upper half structure 11 and the lower half structure 12 of the skull, the surface of the upper half structure 11 is directly unfolded; the radioactive source 3 is arranged on the lofting sheet 41; the cover sheet 42 covers the radioactive source 3, and the edge forms a sealed space with the lofting sheet 41, thereby avoiding the influence of the external environment on the accuracy of the measurement; by arranging the lofting sheet 41 to be the same as the unfolded figure of the surface of the skull 1 corresponding to the parietal bone and frontal bone position, and arranging the radioactive source 3 on the lofting sheet 41, the lofting sheet 41 can be unfolded into a plane when placing the radioactive source 3, thereby reducing the difficulty of arranging the radioactive source 3, and based on the lofting sheet 41 being arranged to be the same as the unfolded figure of the surface of the skull 1 corresponding to the parietal bone and frontal bone position, when the positioning sheet 4 is arranged on the skull 1, only the edge of the positioning sheet 4 needs to be aligned with the edge of the surface of the skull 1 corresponding to the parietal bone and frontal bone position, thereby making the process more convenient; preferably, the skull 1 includes the upper half structure 11 of the skull and the lower half structure 12 of the skull; the lofting sheet 41 is the same as the unfolded figure of the surface of the upper half structure 11 of the skull, and based on the upper half structure 11 of the skull having a definite edge, it is easier to align the edges of the lofting sheet 41 and the upper half structure 11 of the skull, thereby reducing the installation difficulty and improving the installation precision; preferably, the positioning sheet 4 is a flexible sheet to better fit the surface of the skull 1, and the cover sheet 42 can be selected as a sealing film, and more preferably, the melting temperature of the cover sheet 42 is slightly less than the temperature when the equivalent tissue material is poured, such as 1-2℃, thereby the temperature of the cover sheet 42 is increased and melted when pouring, to form a seal between the epidermal layer 2 and the skull 1, thereby on the one hand, the radioactive source 3 is in a sealed environment, and on the other hand, the influence of the cover sheet 42 on the measurement accuracy can be eliminated.

[0049] In some preferred embodiments, the lofting sheet 41 is a water-absorbing sheet, that is, the material is a water-absorbing material, thereby when the radioactive source 3 is arranged, the flow of the radioactive source 3 can be avoided, and the arranged position is more accurate.

[0050] In some preferred embodiments, as shown, Figure 6 As shown, the positioning sheet 4 further includes the hot melt adhesive sheet 43, and the hot melt adhesive sheet 43 is arranged to fit the surface of the skull 1; based on the arrangement of the hot melt adhesive sheet 43, on the one hand, the position adjustment when the positioning sheet 4 is placed is not affected, and on the other hand, when the epidermal layer 2 is poured, the hot melt adhesive sheet 43 is melted to fix the lofting sheet 41 on the surface of the skull 1, thereby avoiding the movement thereof and ensuring the accuracy of the arranged position, that is, the melting temperature of the hot melt adhesive sheet 43 is less than the pouring temperature of the epidermal layer 2.

[0051] In some preferred embodiments, as shown in Figure 1 Further, a marking structure 5 is arranged on the surface of the epidermal layer 2 for positioning during calibration; specifically, the marking structure 5 is a cross line, or other structure capable of achieving positioning alignment; preferably, the marking structure 5 is arranged on the surface of the epidermal layer 2 on the side or top surface of the skull 1; further preferably, the marking structure 5 is made of a radiation-emitting material, which on one hand facilitates alignment in dark light conditions, and on the other hand can also be used to indicate whether the radioactive source 3 has sufficient activity concentration, such as having different colors as the radioactive source 3 decays.

[0052] In some preferred embodiments, the epidermal layer 2 is a structure of elastic material, and the epidermal layer 2 is made of an elastic material that is an equivalent tissue material, which is closer to the real human body.

[0053] In some preferred embodiments, the skull 1 is a structure of resin material, i.e., the resin material is selected as the bone equivalent tissue material.

[0054] Embodiment 2

[0055] The embodiment provides a preparation method of the skull model in the above embodiment 1, and the method comprises the following steps:

[0056] Obtaining a digital skull model; optionally, using the 3D modeling software to establish a digital skull model that can represent the skull of a Chinese adult male, according to the related parameters of the skull of a Chinese male in the book “Chinese Numerical Anatomy”;

[0057] Forming the skull model by three-dimensional printing the digital skull model;

[0058] Manufacturing a skull mold through the skull model;

[0059] Injecting a skull material into the skull mold, demolding, and obtaining the skull 1;

[0060] Arranging the radioactive source 3 on the surface of the skull 1;

[0061] Placing the skull 1 in an epidermal forming mold, injecting an equivalent tissue material (specifically, a gamma radiation equivalent soft tissue), and demolding to obtain the skull model.

[0062] The preparation method of the application is based on arranging the radioactive source 3 on the surface of the skull 1 and using the equivalent tissue material as the epidermal layer 2 to form the skull model, and the amount of the radioactive source 3 is arranged to simulate the amount of the real human body nuclide intake, so that the model can simulate the deposition of the human body after intake of the bone-seeking nuclide in the skull, so as to more accurately calibrate the skull irradiation living body measuring device, thereby improving the measurement accuracy of the nuclide activity in the human body.

[0063] In some preferred embodiments, the radioactive source 3 is arranged on the surface of the skull 1 by the positioning sheet 4, and the step of arranging the radioactive source 3 on the surface of the skull 1 comprises:

[0064] The lofting sheet 41 of the positioning sheet 4 is unfolded, the radioactive source 3 is arranged at the preset position, the covering sheet 42 is covered on the radioactive source 3, and then the lofting sheet 41 is sealed and connected by a plastic sealing machine. Thus, the operation difficulty in arranging the radioactive source 3 is reduced, and the efficiency is improved.

[0065] Embodiment 3

[0066] The embodiment provides a method for preparing a skull model, wherein the skull 1 comprises a skull upper half structure 11 and a skull lower half structure 12; the skull upper half structure 11 comprises a parietal bone part 111 and a frontal bone part 112; the skull lower half structure 12 is a remaining part of the skull 1 except the parietal bone part 111 and the frontal bone part 112; the epidermal layer 2 comprises an upper half epidermal layer 21 and a lower half epidermal layer 22 which are adhesively connected; the upper half epidermal layer 21 is arranged on the surface of the skull upper half structure 11; and the method comprises the following steps:

[0067] segmenting a digital skull model into a skull upper half part comprising a parietal bone and a frontal bone, and a skull lower half part;

[0068] forming a skull upper half model and a skull lower half model by three-dimensional printing respectively from the skull upper half part and the skull lower half part;

[0069] manufacturing a skull upper half mold and a skull lower half mold respectively from the skull upper half model and the skull lower half model;

[0070] injecting a resin material into the skull upper half mold and the skull lower half mold, and demolding to obtain the skull upper half structure 11 and the skull lower half structure 12;

[0071] arranging the radioactive source 3 on the surface of the skull upper half structure 11;

[0072] placing the skull upper half structure 11 and the skull lower half structure 12 in corresponding scalp forming molds respectively;

[0073] injecting a tissue equivalent material into the scalp forming molds, and demolding to obtain the skull upper half structure 11 with the upper half epidermal layer 21 and the skull lower half structure 12 with the lower half epidermal layer 22;

[0074] splicing the skull upper half structure 11 and the skull lower half structure 12, and adhesively connecting the upper half epidermal layer 21 and the lower half epidermal layer 22 to obtain the skull model.

[0075] The preparation method of the present application is based on preparing the upper half skull structure 11 and the lower half skull structure 12 respectively, wherein the upper half skull structure 11 for placing the radioactive source is more complex, and separate preparation can reduce the volume of preparation, reduce the difficulty of preparation, and improve the efficiency.

[0076] In some preferred embodiments, the material for bonding the upper half epidermis layer 21 and the lower half epidermis layer 22 is the same equivalent tissue material as the epidermis layer 2.

[0077] In some preferred embodiments, the radioactive source 3 is arranged on the surface of the skull 1 through the positioning sheet 4, and the step of arranging the radioactive source 3 on the surface of the skull 1 comprises:

[0078] The lofting sheet 41 of the positioning sheet 4 is unfolded, the radioactive source 3 is arranged at the preset position, the covering sheet 42 is covered on the radioactive source 3, and then the covering sheet 42 is sealed and connected with the lofting sheet 41 through a plastic sealing machine. In this way, the operation difficulty in arranging the radioactive source 3 is reduced, and the efficiency is improved.

[0079] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative but not restrictive. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, and all of them belong to the protection of the present application.

Claims

1. A head phantom for calibration of in-vivo dosimetry devices for cranial irradiation, characterized in that, The skull, the epidermal layer and the radioactive source are included. The radioactive source is arranged on the surface of the skull and is located on the parietal bone and the frontal bone of the skull. The epidermal layer is fixed on the surface of the skull by pouring and is a tissue equivalent material. The radioactive source is a point radioactive source and has a plurality of point radioactive sources which are uniformly distributed on the surface of the parietal bone and the frontal bone of the skull. The radioactive source is arranged on the surface of the parietal bone and the frontal bone of the skull by the positioning sheet. The positioning sheet includes a lofting sheet and a cover sheet. The lofting sheet has the same shape as the surface of the parietal bone and the frontal bone of the skull, and the radioactive source is arranged on the lofting sheet. The cover sheet covers the radioactive source and forms a sealed space with the edge of the lofting sheet.

2. The head model for calibration of in-vivo measurement devices for intracranial irradiation according to claim 1, characterized in that, The skull includes an upper half structure of the skull and a lower half structure of the skull. The upper half structure of the skull includes a parietal bone part and a frontal bone part, and the lower half structure of the skull is the remaining part of the skull except the parietal bone part and the frontal bone part. The epidermal layer includes an upper half epidermal layer and a lower half epidermal layer which are adhesively connected. The upper half epidermal layer is arranged on the surface of the upper half structure of the skull. The lower half epidermal layer is arranged on the surface of the lower half structure of the skull.

3. The head model for calibration of in-vivo measurement devices for intracranial irradiation according to claim 1, characterized in that, The lofting sheet is a water-absorbing sheet.

4. The head phantom for calibration of in-vivo head-phantom dosimetry devices according to any of claims 1 to 3, characterized in that A marking structure is further included. The marking structure is arranged on the surface of the epidermal layer and is used for positioning during calibration.

5. The head phantom for calibration of in-vivo head-phantom dosimetry devices according to any of claims 1-3, characterized in that, The epidermal layer is a structure of elastic material.

6. The head phantom for calibration of in-vivo head-phantom dosimetry devices according to any of claims 1-3, characterized in that, The skull is a structure of resin material.

7. A method of producing a head model according to any one of the preceding claims 1 to 6, characterized in that, The method includes the following steps: A digital model of the skull is obtained. The digital model of the skull is formed into a skull model by three-dimensional printing. A skull mold is manufactured by the skull model. A skull material is injected into the skull mold, and the skull is obtained by demolding. A radioactive source is arranged on the surface of the skull. The skull is placed in an epidermal forming mold, a tissue equivalent material is injected, and a skull model is obtained by demolding.

8. A method of producing a head model according to any one of claims 2 to 6, characterized in that, The method includes the following steps: The digital model of the skull is divided into an upper half skull including a parietal bone and a frontal bone, and a lower half skull. The upper half skull and the lower half skull are formed into an upper half skull model and a lower half skull model by three-dimensional printing. An upper half skull mold and a lower half skull mold are manufactured by the upper half skull model and the lower half skull model, respectively. An upper half skull structure and a lower half skull structure are obtained by injecting a resin material into the upper half skull mold and the lower half skull mold and demolding. A radioactive source is arranged on the surface of the upper half skull structure. The upper half skull structure and the lower half skull structure are placed in corresponding epidermal forming molds, respectively. A tissue equivalent material is injected into the epidermal forming molds, and an upper half epidermal layer of the upper half skull structure and a lower half epidermal layer of the lower half skull structure are obtained by demolding. The upper half skull structure and the lower half skull structure are spliced, and the upper half epidermal layer and the lower half epidermal layer are adhesively connected, to obtain a skull model.

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