Computed tomography (CT)-guided pelvic organ group module for vagina posterior fornix puncture injection

Abstract

The invention relates to the technical field of medical teaching aids or medical experimental models, and discloses a CT-guided vagina posterior fornix puncture injection pelvic organ group module, a manufacturing method of the CT-guided vagina posterior fornix puncture injection pelvic organ group module and a female pelvic cavity model. The pelvic organ group module or the female pelvic cavity model provided by the invention is used for the training of the current clinical improved operation of transvaginal posterior fornix puncture injection of biological gel, so that the technology can be popularized as soon as possible, and the reliability and the safety of a transvaginal posterior fornix medical isolation rubber injection puncture operation based on CT guidance are improved.

Description

Technical Field

[0001] The present application relates to the technical field of medical teaching aids or medical experimental models, and in particular to a CT-guided posterior vaginal fornix puncture and injection pelvic organ group module, a manufacturing method thereof, and a female pelvic model. Background Art

[0002] Radiotherapy is one of the main means of treating cervical cancer. When IB-IVA cervical cancer patients are given a biological equivalent dose of 85Gy or more for cervical tumors, radical treatment can be achieved. However, high-dose irradiation is bound to cause damage to adjacent normal organs such as the rectum and bladder. In severe cases, it can lead to long-term repeated blood in the stool, blood in the urine, or fistula complications after radiotherapy, affecting the patient's quality of life. Medical isolation glue is a hydrogel with good biocompatibility. When injected into the cervical-rectal gap, it can push the rectum away and protect normal organs during high-dose radiotherapy of the cervix. It can be absorbed and metabolized by itself several months after radiotherapy. At present, a commonly used method of injecting medical isolation glue is to inject the isolation glue through perineal puncture under the guidance of rectal ultrasound. Because this operation involves skilled operation and use of ultrasound equipment, it is difficult for doctors who have no experience in using ultrasound equipment.

[0003] Another new method currently used in clinical practice is to use the most commonly used CT in the radiotherapy department as a positioning device to inject biogel through the posterior fornix of the vagina. The injection path is shorter and the puncture damage is smaller. However, in order to avoid the need for the puncture needle to directly penetrate the rectum, surrounding normal tissues and compartment scanning, a qualified operator must go through years of practical practice and experience accumulation to perform clinical skills operations well. Therefore, it still takes a lot of surgical practice to train a skilled operator. However, the learning cycle of this technology is long, the learning cost is high, and the high risk in the training process is also an important reason why most instructors are reluctant to let go of trainees easily. The above factors ultimately lead to certain difficulties in the popularization of this technology.

[0004] Therefore, in order to improve the reliability and safety of CT-guided transvaginal posterior fornix medical isolation glue injection puncture surgery, it is of great significance to design and manufacture a female pelvic organ group entity model that can be used for puncture mechanics experiments and puncture training. Simulators are becoming more and more important in surgical training. On the one hand, it is due to the limited working time of residents and the increasing emphasis on the training of basic abilities. On the other hand, surgical simulators have a variety of inherent advantages, which can meet the needs of efficient training, simulate preoperative training, conduct metering planning, and experimental research on the interaction mechanics between puncture needles and tissues, which is also very necessary for improving the success rate and efficacy of surgery. The smaller the difference in structure and material morphology between the simulator and the simulated object, the more obvious the training effect of the simulator. Although there are posterior fornix puncture models in the prior art, the existing models are all puncture and fluid collection models, and the simulation of the current puncture models is not high. For example, the posterior fornix puncture model disclosed in the standardized patient for puncture and fluid collection in the open patent document CN107886825A high-simulation gynecological surgical skills simulation training may be due to the low demand for simulation on the one hand and the limitation of model production cost on the other hand. Summary of the invention

[0005] The main purpose of the present invention is to provide a pelvic organ group module for posterior vaginal fornix puncture and injection and a manufacturing method thereof and a female pelvic model that can be guided by CT. The pelvic organ group module or the female pelvic model is used for training the improved operation of the current clinical transvaginal posterior fornix puncture and injection of biological gel, so that this technology can be popularized as soon as possible, and the reliability and safety of the transvaginal posterior fornix medical isolation gel injection puncture surgery based on CT guidance can be improved.

[0006] The present invention is based on three-dimensional reconstruction technology and, through the selection and preparation of bionic materials, obtains a pelvic organ group module or a female pelvic model with mechanical properties similar to those of real biological tissues. Taking into account the production cost of the model, the present invention has carried out low-cost optimization design in the structural design and production of the pelvic organ group module, which can achieve high simulation while also realizing the reusability of the pelvic organ group module.

[0007] Based on the above objectives, the first aspect of the present invention provides a CT-guided posterior vaginal fornix puncture and injection module for pelvic organs, such as Figure 1 As shown, the pelvic organ group module is a module made of silicone and contains a pelvic organ cavity, wherein the pelvic organ cavity includes a bladder such as Figure 1 (a) The urinary tract and uterus connected to the bladder Figure 1 (b) The vagina and rectum connected to the uterus in the female pelvis Figure 1(c) in the pelvic organ group module; the pelvic organ group module also includes a detachable puncture replacement block, the puncture replacement block is a replacement block composed of the lower half of the vaginal cavity wall from the vaginal opening to the posterior vaginal fornix and the upper half of the rectal wall adjacent to the lower half of the vaginal cavity, and the puncture replacement block also reserves a hydrogel injection cavity, and the position of the hydrogel injection cavity is the position between the posterior vaginal fornix and the rectal wall; Figure 2 The picture shows the vaginal side view of the puncture replacement block. Figure 1 The (A) side of Figure 3 The picture shows the rectal side of the puncture replacement block. Figure 1 (B) side.

[0008] In order to achieve a more realistic vaginal wall puncture feel and take into account the CT imaging effect, the silicone is food-grade liquid silicone. The mechanical properties of the food-grade liquid silicone after curing must meet the following conditions: the material density is 1.1-1.16 g / cm 3 ; Hardness (ShoreA) is 20-70A; Tensile strength is 7.0-10.2MPa; Elongation at break is 100%-700%; Tear strength is 8-58KN / m; The food-grade silica gel includes but is not limited to terminal hydroxyl polyphenylsiloxane, dihydroxy polydimethylsiloxane, or silica gel material provided in the patent document with publication number CN108329694B;

[0009] Further preferably, the mechanical properties of the food-grade silica gel meet the following conditions: hardness (Shore A) is 30A; tensile strength: 4.5±0.5MPa; elongation at break: 350%; tear strength: 12±2KN / m.

[0010] By adopting the above technical scheme, firstly, the cavity in the pelvic organ group module is highly simulated with the organ cavity in the real female pelvis. This pelvic organ group module can display the cavity position through CT development, which is highly similar to the real female pelvic CT development photos, which is conducive to training novices to conduct puncture simulation training through CT guidance. After the puncture training, CT development can also be performed to judge the accuracy of the puncture injection position. The training process is the same as the real pre- and post-operative diagnosis process of puncture, achieving highly simulated training; in addition, by designing a puncture replacement block as a replaceable puncture injection area, the pelvic organ group module can be used again after it can be pulled out and replaced with a new puncture replacement block after use, effectively reducing costs and repeated puncture training.

[0011] Since the difference between the injected hydrogel and the silicone in the replacement block under CT is limited, in order to more clearly and quickly judge the experimental results of injection puncture, for example, whether the injected hydrogel is excessively punctured through the vagina, resulting in puncture damage to the rectum; as a preferred embodiment of the present application, Figure 4As shown, the inner surface of the lower half of the vaginal cavity wall and the upper half of the rectal wall of the puncture replacement block or the inner surface within 1 mm from the inner surface is uniformly doped with CT-developable materials such as Figure 4 The black interlayer shown at (a) in the middle; the CT-developable material such as barium sulfate can more obviously make the injected filled hydrogel as shown in FIG. Figure 4 The cavity wall shown in (b) is distinguished from the cavity wall in the replacement block.

[0012] In a second aspect, the present invention further provides a female pelvic model, comprising: a model shell, a pelvic module and the pelvic organ group module described in the first aspect of the present invention; the pelvic organ group module and the pelvic module are assembled and placed in the model shell; the model shell is a plastic shell whose facade shape matches the shape of the female pelvic structure, and in order to facilitate installation and disassembly, the model shell is at least a two-homolar shell, which is fixed with glue or bolts.

[0013] By adopting the above-mentioned technical scheme, the pelvic organ group module and the pelvic module described in the first aspect of the present invention are assembled and placed in a model shell to make a female pelvic model, which can slow down the aging of silicone, avoid external force damage and environmental damage during use, and extend the service life of the pelvic organ group module.

[0014] In a third aspect, the present invention further provides a method for manufacturing the pelvic organ group module according to the first aspect, the steps of the manufacturing method comprising:

[0015] Three-dimensional reconstruction of female pelvic organ group based on medical images; production of female main pelvic model; production of transvaginal posterior fornix puncture replacement block; based on the real anatomical structure of the human body, assemble the main pelvic cavity and puncture replacement block into a pelvic organ group module.

[0016] By adopting the above technical solution, a model that is closer to the structure and morphology of female pelvic organs can be produced, which is conducive to the simulation of puncture and injection training, improves the efficiency of training, and achieves high simulation while also achieving the reusability of the model. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic structural diagram of the pelvic organ group module;

[0018] Figure 2 Observation of the vaginal cavity wall for the replacement block;

[0019] Figure 3 Observation of the rectal lumen wall for the replacement block;

[0020] Figure 4 is a schematic diagram of the position of the developable material in the replacement block;

[0021] Figure 5 The CT data and three-dimensional reconstruction results of the pelvic model designed based on the desensitized CT data in Example 1;

[0022] Fig. 6A A schematic diagram of the state of assembling the mold for making the puncture replacement block in Example 1 and for the first pouring;

[0023] Figure 6B A schematic diagram of the state of making a mold for the puncture replacement block in Example 1 for the second and third pouring;

[0024] Figure 6C A schematic diagram of the state of making a mold for the puncture replacement block in Example 1 for the fourth and fifth pouring;

[0025] Fig. 6A , Figure 6B and Figure 6C In the figure, 1 is the upper casting mold; 1-1 is the first exhaust hole; 1-2 is the second exhaust hole; 1-3 is the first glue injection port; 3 is the lower casting mold; 3-1 is the third exhaust hole; 3-2 is the fourth exhaust hole; 3-3 is the second glue injection port; 4 is the middle casting mold; 4-1 is the fifth exhaust hole; 4-2 is the sixth exhaust hole; 4-3 is the third glue injection port;

[0026] Fig.6D The manufacturing process of the injection cavity in the puncture replacement block in Example 1;

[0027] Figure 7 These are photos related to the surgical simulation process of puncture and injection of medical isolation glue using a female pelvic model in Example 1;

[0028] Figure 8 The CT images are those involved in the surgical simulation process of the female pelvic model in Example 1;

[0029] Fig. 9 Schematic diagram of the three-dimensional structure of the hard paraffin core in Example 1;

[0030] Fig.10 This is a tooling structure diagram of the hard paraffin core and PC outer casting mold of Example 1. DETAILED DESCRIPTION

[0031] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0032] In order to make the purpose, process conditions and advantages of the present invention more clearly understood, the present invention is further described in detail in conjunction with the following embodiments, but the embodiments of the present invention are not limited thereto. Without departing from the above-mentioned technical ideas of the present invention, various substitutions and changes are made according to the common technical knowledge and customary means in the field, which should all be included in the scope of the present invention. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0033] Sources of some of the raw materials used in the following examples:

[0034] Liquid silicone is food grade liquid silicone. The mechanical properties after curing are as follows: Material density: 1.1g / cm 3 ; Hardness (ShoreA): 30A; Tensile strength: 4.5±0.5MPa; Elongation at break: 350%; Tear strength: 12±2KN / m. After curing, this liquid silicone material can more realistically simulate the feel of vaginal wall puncture. Ordinary 3D printing cannot directly print a silicone model of this strength.

[0035] Barium sulfate CAS: 7727-43-7, purchased from Aladdin;

[0036] Hard paraffin wax was purchased from Shanghai Better Chemical Co., Ltd., model No. 54 paraffin wax, melting point range: 54-56°C.

[0037] Example 1: Preparation of pelvic organ group module

[0038] 1. 3D reconstruction of female pelvic organs based on medical images

[0039] like Figure 5 As shown in the figure, based on the desensitized CT data and combined with the knowledge of pelvic anatomy, 3D Slicer version 4.10.1 was used to convert the CT scan data into a triangular patch format file for manual segmentation and three-dimensional reconstruction of the female pelvic organ group. By cropping to display the pelvic area and using the threshold function to select the inner cavity of the bladder, uterus, rectum, urethra and vagina, the generated model was imported into Blender software for carving to fit the pelvic frame. The digital soft tissue model was imported into Autodesk Fusion360 version 2.0.6263 for creating a mold.

[0040] 2. Design and production of pelvic organ group module

[0041] The pelvic organ group module of this embodiment is manufactured by using a silicone injection method, and the specific steps are as follows:

[0042] ① Make an external casting mold: Use PC material 3D machine printing to make a PC external casting mold, such as Fig.10 The gray part in the figure is the structure of the PC outer casting mold, and the inner surface of the mold is polished.

[0043] ② Make the paraffin core of pelvic organs: First, 3D print each pelvic organ core casting mold according to the three-dimensional data, which is printed by a high-precision 3D printing machine. The mold surface is sandblasted to remove the printing texture, and then electroplated and polished to ensure the smoothness of the surface; after the mold is closed, the core mold is heated to 70 degrees, and after keeping warm for two hours, the hard paraffin is heated and dissolved, injected into the core mold and put back into the heating device to slowly cool down, and the temperature is controlled to drop by 20-25 degrees in half an hour. After cooling to room temperature, the hard paraffin is demolded after it is completely cooled, and the hard paraffin core is taken out. Fig. 9 As shown, the hard paraffin core includes a paraffin core in the shape of a puncture replacement block, which is convenient for reserving insertion space for the puncture replacement block after subsequent demolding. The pelvic organ paraffin core also includes a fixing block for fixing the organ paraffin model. The fixing block is also provided with a positioning hole, which is used for assembling the entire pelvic organ paraffin core with the external casting mold. Hard paraffin is stronger than paraffin and is easier to assemble and subsequently mold.

[0044] ③ Make pelvic organ group module: Fig.10 As shown, referring to the position of the positioning holes, assemble the external casting mold and the pelvic organ paraffin core. After fixing the pelvic organ paraffin core, inject liquid silicone into the casting hole of the external casting mold by liquid silicone equipment, place it in a heating device with a humidity less than 55 and a temperature of 30 degrees for six hours to demold after the silicone is cured.

[0045] Due to the complex structure of the model, the commonly used physical demoulding method cannot be used to completely demold the model, which will damage the bladder and uterine structure in the silicone model. Therefore, the model is heated to 100 degrees to completely melt the hard paraffin core and then demolded to obtain a complete pelvic model.

[0046] 3. Design and production of puncture replacement block

[0047] Make PC upper, middle and lower casting molds: Use PC material 3D machine printing to make PC material upper casting mold, middle casting mold and lower casting mold, and polish the inner surface of the mold; Fig. 6A As shown, the upper casting mold 1 has a first vent hole 1-1, a second vent hole 1-2, and a first glue injection port 1-3; the lower casting mold 3 has a third vent hole 3-1, a fourth vent hole 3-2, and a second glue injection port 3-3; the middle casting mold 4 has a fifth vent hole 4-1, a sixth vent hole 4-2, and a third glue injection port 4-3.

[0048] In order to distinguish the vaginal posterior wall and the rectal anterior wall under CT and better observe the puncture and injection sites, Example 1 is a preferred embodiment, and CT developing materials are used at about 1mm of the vaginal posterior wall and about 1mm of the rectal anterior wall in the replacement block. The developing material formula is a uniform mixture of liquid silica gel and barium sulfate. Figure 4As shown, the arrow indicates the CT contrast layer of the anterior wall of the rectum. Similarly, the posterior wall of the vagina also contains a CT contrast layer approximately 1 mm away.

[0049] Specifically, the steps of making a replacement block with a developing layer are as follows:

[0050] like Fig. 6A As shown, the upper casting mold 1, the middle casting mold 4 and the lower casting mold 3 are assembled. The production process has a total of five casting operations. After each casting operation, it needs to be cured before the next casting operation. The conditions for each curing are: the mold is placed in a heating device with a humidity of less than 55 and a temperature of 30 degrees for six hours to wait for the silicone to cure; the first casting is to inject pure liquid silicone from the third injection port 4-3. After the silicone is cured, Figure 6B As shown, the mold is placed with the upper casting mold 1 facing upward, and the developing silicone is injected from the first injection port 1-3 to complete the second casting. After the silicone is solidified, a small amount of pure liquid silicone is injected from the first injection port 1-3 to completely cover the developing silicone layer, that is, the third casting is completed. After the silicone is solidified, Figure 6C As shown, the mold is placed with the lower casting mold 3 facing upward, and the developing silicone is injected from the second injection port 3-3 to complete the fourth casting. After the silicone is solidified, a small amount of pure liquid silicone is injected from the second injection port 3-3 to completely cover the developing silicone layer, and the fifth casting is completed and demoulding is completed;

[0051] After demoulding, the silicone block is formed into one piece. From the side of the silicone block, Fig.6D The position A shown is opened with a knife, and a space is reserved by cutting horizontally along the direction of the dotted arrow, which is used as the injection cavity position for injecting hydrogel in the puncture replacement block later. The cutting depth does not exceed 5 cm and the width does not exceed 1.5 cm. After cutting, the cutting crack generated at the position A is sealed with a small amount of liquid silicone as silicone adhesive, that is, Fig.6D The crack in the framed area B shown in the figure can be sealed, because the liquid silicone used to bond the side opening and the liquid silicone used to make the replacement block are the same type of silicone, so the silicone has a certain "self-healing" ability after curing, and becomes one with the original silicone material, and will not affect the next puncture experiment.

[0052] Example 2 Female pelvic model assembly

[0053] Based on the real anatomical structure of the human body, the pelvic organ group module and the puncture replacement block prepared in Example 1 are assembled together with the pelvic model in the model shell to form a female pelvic model.

[0054] Experimental example: Using the model for surgical simulation training

[0055] Experimental validation of CT-guided transvaginal posterior fornix puncture of medical isolation glue, such as Figure 7As shown, a surgical simulation of puncturing the medical isolation glue through the posterior fornix of the vagina under CT guidance was performed. Specifically, the following were included:

[0056] ①Prepare puncture objects: Figure 7 As shown in Figure (a) in the figure, a puncture needle, a needle channel mold, a complete replacement block without cracks, and a double syringe containing hydrogel are prepared respectively. The needle channel mold is used as a guide rod for vaginal wall puncture. Its structure and materials refer to the patent document with publication number CN220175206U. The replacement block is installed in the female pelvic cavity model. The installed model is as shown in Figure 7 As shown in Figure (b);

[0057] ② If Figure 7 As shown in Figure (c), the puncture needle and needle channel mold are placed into the vagina, and then a CT scan is performed to confirm the position of the needle tip. The CT scan photo corresponds to Figure 8 Figure (a) in the figure;

[0058] ③ Push the puncture needle into the vaginal rectal septum and perform a CT scan again to confirm that the needle tip is fully inserted. The CT scan photo corresponds to Figure 8 Figure (b) in the figure;

[0059] ④ After injecting 0.5 ml of saline, perform a CT scan to ensure that the liquid can be smoothly injected into the vaginal rectal septum. The CT scan photo corresponds to Figure 8 Figure (c) in the figure;

[0060] ⑤ Such as Figure 7 As shown in Figure (d), 2 ml of biological isolation glue was injected using a double syringe. After the glue solidified, a CT scan was performed again to confirm the injection effect. The CT scan photo corresponds to Figure 8 Figure (d) in the figure;

[0061] ⑥ Remove the puncture needle first, then remove the needle track mold;

[0062] It can be seen from the surgical simulation training experiment that the simulation model has good authenticity and operability in the experiment of puncturing the medical isolation glue through the posterior fornix of the vagina under CT guidance, and can be used for repeated puncture practice, which is conducive to improving relevant clinical skills and understanding relevant knowledge.

Claims

1. A CT-guided posterior vaginal fornix puncture and injection module for pelvic organs, characterized in that: The pelvic organ group module is a module made of silicone and contains a pelvic organ cavity, wherein the pelvic organ cavity includes a bladder and a urinary tube connected to the bladder, a uterus and a vagina connected to the uterus, and a rectal segment in the female pelvic cavity; the pelvic organ group module also includes a detachable puncture replacement block, wherein the puncture replacement block is a replacement block composed of the lower half of the vaginal cavity wall from the vaginal opening to the posterior vaginal fornix and the upper half of the rectal cavity wall adjacent to the lower half of the vagina, and the puncture replacement block also reserves a hydrogel injection cavity, and the position of the hydrogel injection cavity is the position between the posterior vaginal fornix and the rectal wall.

2. The pelvic organ group module according to claim 1, characterized in that: The silica gel is food grade liquid silica gel, and the mechanical properties of the food grade liquid silica gel after curing must meet the following conditions: the material density is 1.1-1.16 g / cm 3 ; Hardness is 20~70A; Tensile strength is 7.0~10.2MPa; Elongation at break is 100%~700%; Tear strength is 8~58KN / m.

3. The pelvic organ group module according to claim 2, characterized in that: The food-grade silica gel is hydroxy-terminated polyphenylsiloxane, dihydroxy polydimethylsiloxane, or the silica gel material provided in the patent document with publication number CN108329694B.

4. The pelvic organ group module according to claim 2, characterized in that: The mechanical properties of the food-grade silica gel meet the following conditions: hardness of 30A; tensile strength: 4.5±0.5MPa; elongation at break: 350%; tear strength: 12±2KN / m.

5. The pelvic organ group module according to claim 1, characterized in that: The inner surface of the lower half of the vaginal cavity wall and the upper half of the rectal cavity wall of the puncture replacement block or the area within 1 mm from the inner surface is uniformly doped with CT-developable material.

6. The pelvic organ group module according to claim 5, characterized in that: The developable material is barium sulfate.

7. A female pelvic cavity model, comprising: A model shell, a pelvic module, and a pelvic organ group module as claimed in claim 1; The pelvic organ group module and the pelvic module are assembled and placed in the model shell; The model shell is a plastic shell whose facade shape matches the shape of the female pelvic structure.

8. The method for manufacturing the pelvic organ group module according to claim 1, the steps of the manufacturing method comprising: 3D reconstruction of female pelvic organ groups based on medical images; Production of female subject pelvic model; Fabrication of a transvaginal posterior fornix puncture replacement block; Based on the real anatomical structure of the human body, the main pelvic cavity and the puncture replacement block are assembled into a pelvic organ group module.

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