Pelvic organ group module for CT-guidable puncture injection via posterior fornix of vagina
By using 3D reconstruction and biomimetic materials to create pelvic organ group modules, combined with CT imaging materials, the problems of low simulation accuracy and high training costs of existing models have been solved. This has achieved high simulation accuracy and reusable puncture training, improving the reliability and safety of CT-guided transvaginal posterior fornix medical isolation gel injection puncture surgery.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANGHAI RUINING BIOTECH CO LTD
- Filing Date
- 2025-08-26
- Publication Date
- 2026-07-02
AI Technical Summary
The existing models for posterior vaginal fornix puncture are not highly realistic and have high training costs, which makes it difficult to popularize CT-guided transvaginal posterior fornix medical isolation glue injection puncture surgery.
Using 3D reconstruction technology and biomimetic materials, a pelvic organ group module with mechanical properties similar to real biological tissues was created. Combined with CT imaging materials, it achieves high simulation and reusability, and puncture training was conducted through the pelvic organ group module.
It improves the reliability and safety of puncture surgery, reduces training costs, and achieves highly realistic puncture training results, making it suitable for beginners to conduct puncture simulation training under CT guidance.
Smart Images
Figure CN2025117072_02072026_PF_FP_ABST
Abstract
Description
A CT-guided posterior fornix puncture and injection pelvic organ group module Technical Field
[0001] This application relates to the field of medical teaching aids or medical experimental models, and in particular to a CT-guided posterior fornix puncture and injection pelvic organ group module, its manufacturing method, and a female pelvic model. Background Technology
[0002] Radiotherapy is one of the primary treatments for cervical cancer. When IB-IVA cervical cancer patients receive a biologically equivalent dose of 85 Gy or higher, radical treatment can be achieved. However, high-dose radiation inevitably damages adjacent normal organs such as the rectum and bladder. In severe cases, it can lead to long-term recurrent rectal bleeding, hematuria, or fistulas, affecting the patient's quality of life. Medical isolation gel is a biocompatible hydrogel that, when injected into the cervicorectal space, can push the rectum aside, protecting normal organs during high-dose cervical radiotherapy. It is absorbed and metabolized naturally within a few months after radiotherapy. Currently, a commonly used method for injecting medical isolation gel is perineal puncture under rectal ultrasound guidance. Because this procedure requires skilled operation of ultrasound equipment, it presents a certain challenge for doctors without experience using ultrasound equipment.
[0003] Another emerging clinical method involves using CT scans, commonly used in radiotherapy, as the localization device for transvaginal posterior fornix injection of the bio-gel. This method offers a shorter injection path and less puncture damage. However, to avoid direct needle penetration into the rectum, surrounding normal tissue, and the need for compartment scanning, a qualified surgeon must undergo years of practice and experience to master the clinical skills. Therefore, training a skilled surgeon still requires extensive surgical practice. Furthermore, the long learning curve and high cost of this technique, along with the high risks involved in training, are significant reasons why most instructors are reluctant to readily hand over their training. All these factors ultimately hinder the widespread adoption of this technique.
[0004] Therefore, to improve the reliability and safety of CT-guided transvaginal posterior fornix medical isolation gel injection puncture surgery, designing and fabricating a physical model of the female pelvic organ system applicable to puncture mechanics experiments and puncture training is of great significance. Simulators are becoming increasingly important in surgical training, partly due to the time constraints of resident physicians and the growing emphasis on basic skills training, and partly because surgical simulators possess several inherent advantages that meet the needs of efficient training. They can simulate preoperative training, conduct metrological planning, and perform experimental research on the interaction mechanics of the puncture needle and tissue, which is essential for improving surgical success rates and efficacy. The smaller the structural and material differences between the simulator and the simulated object, the more significant the training effect of the simulator. Although existing technologies provide models for posterior fornix puncture, these models are all for puncture and fluid extraction, and their simulation accuracy is not high. For example, the posterior fornix puncture model disclosed in patent document CN107886825A, a high-fidelity gynecological surgical skills simulation training for standardized patients, may be due to the low simulation requirements for puncture and fluid extraction, or limitations in model manufacturing costs. Summary of the Invention
[0005] The main objective of this invention is to provide a CT-guided posterior fornix puncture and injection pelvic organ group module, its fabrication method, and a female pelvic model. The pelvic organ group module or female pelvic model is used for training in the current clinical practice of improved operation of transvaginal posterior fornix puncture and injection of biogel, so that this technology can be popularized as soon as possible, and the reliability and safety of CT-guided transvaginal posterior fornix medical isolation gel injection puncture surgery can be improved.
[0006] Based on three-dimensional reconstruction technology, this invention obtains a pelvic organ group module or female pelvic model with similar mechanical properties to real biological tissues through the selection and preparation of biomimetic materials. Considering the production cost of the model, this invention has carried out low-cost optimization design in the structural design and production of the pelvic organ group module, achieving high simulation while also enabling the reusability of the pelvic organ group module.
[0007] Based on the above objectives, in a first aspect, the present invention provides a CT-guided posterior fornix puncture and injection pelvic organ group module, as shown in Figure 1. The pelvic organ group module is a module made of silicone containing pelvic organ cavities. The pelvic organ cavities include the bladder (Figure 1, ab) and the urinary tract connected to the bladder, the uterus (Figure 1, b) and the vagina connected to the uterus, and the rectal segment in the female pelvis (Figure 1, c). The pelvic organ group module also includes a separable puncture replacement block, which is a replacement block composed of the lower half of the vaginal cavity wall from the vaginal opening to the posterior fornix and the upper half of the rectal wall adjacent to this lower half of the vaginal cavity. The puncture replacement block also has a reserved injection cavity for hydrogel, the injection cavity of which is located between the posterior fornix of the vagina and the rectal wall. Figure 2 shows a vaginal side observation photograph of the actual puncture replacement block corresponding to side (A) in Figure 1, and Figure 3 shows a rectal side observation photograph of the actual puncture replacement block corresponding to side (B) in Figure 1.
[0008] To more closely resemble the feel of vaginal wall puncture while also ensuring good imaging results under CT scans, the silicone used is food-grade liquid silicone. The mechanical properties of the cured food-grade liquid silicone must meet the following conditions: material density of 1.1–1.16 g / cm³. 3 The hardness (Shore A) is 20-70A; the tensile strength is 7.0-10.2MPa; the elongation at break is 100%-700%; the tear strength is 8-58KN / m; the food-grade silicone includes, but is not limited to, hydroxyl-terminated polyphenylsiloxane, dihydroxy polydimethylsiloxane, or the silicone material provided in the patent document with publication number CN108329694B;
[0009] More preferably, the mechanical properties of the food-grade silicone meet the following conditions: hardness (Shore A) of 30A; tensile strength: 4.5±0.5MPa; elongation at break: 350%; tear strength: 12±2KN / m.
[0010] By adopting the above technical solution, firstly, the cavities in the pelvic organ group module are highly simulated to the cavities of organs in the real female pelvis. This pelvic organ group module can display the location of the cavities through CT imaging, which is highly similar to the CT images of the real female pelvis. This is beneficial for training novices to perform puncture simulation training under CT guidance. After puncture training, CT imaging can be performed again to determine the accuracy of the puncture injection site. The training process is the same as the pre- and post-operative diagnostic process of real 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 reused after use and replaced with a new puncture replacement block, effectively reducing costs and allowing for repeated puncture training.
[0011] Since the difference between the injected hydrogel and the silicone in the replacement block is limited under CT, in order to more clearly and quickly determine the experimental results of the injection puncture, such as whether the injected hydrogel was excessively punctured through the vagina, resulting in puncture damage to the rectum; as a preferred embodiment of this application, as shown in Figure 4, the inner surface of the lower vaginal cavity wall and the upper rectal cavity wall of the puncture replacement block, or within 1 mm of the inner surface, is uniformly doped with a CT-reproducible material, as shown in the black interlayer at (a) in Figure 4; the CT-reproducible material, such as barium sulfate, can more clearly distinguish the injected hydrogel, as shown in (b) in Figure 4, from the cavity wall in the replacement block by increasing the amount of profiling material.
[0012] Secondly, the present invention also provides a female pelvic model, which includes: 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 with an external shape that matches the shape of the female pelvic structure, and in order to facilitate installation and disassembly, the model shell is at least a two-part shell, which is fixed between the two parts by glue or bolts.
[0013] By adopting the above technical solution, the pelvic organ group module and the pelvic module described in the first aspect of the present invention are assembled and placed in the 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] Thirdly, the present invention also provides a method for manufacturing the pelvic organ group module described in the first aspect above, the method comprising the following steps:
[0015] Three-dimensional reconstruction of the female pelvic organ system based on medical images; fabrication of the female main pelvic model; fabrication of the transvaginal posterior fornix puncture replacement block; and assembly of the main pelvic model and the puncture replacement block into a pelvic organ system module based on the actual human anatomical structure.
[0016] By adopting the above technical solutions, models that more closely resemble the structure and morphology of female pelvic organs can be created, which is beneficial to the simulation of puncture and injection training, improves training efficiency, and achieves high simulation while also enabling model reusability. Attached Figure Description
[0017] Figure 1 is a structural schematic diagram of the pelvic organ group module;
[0018] Figure 2 is an observation of the vaginal wall of the replacement block;
[0019] Figure 3 shows an observation of the rectal wall of the replacement block;
[0020] Figure 4 is a schematic diagram showing the position of the developable material in the replacement block;
[0021] Figure 5 shows the CT data and three-dimensional reconstruction results of the pelvic model designed based on desensitized CT data in Example 1;
[0022] Figure 6A is a schematic diagram of the assembly of the mold for making the puncture replacement block in Example 1 and its state for the first pouring;
[0023] Figure 6B is a schematic diagram of the state of the puncture replacement block manufacturing mold used for the second and third pouring in Example 1;
[0024] Figure 6C is a schematic diagram of the state of the puncture replacement block mold used for the fourth and fifth pouring in Example 1;
[0025] In Figures 6A, 6B, and 6C, 1 represents the upper casting mold; 1-1 represents the first vent; 1-2 represents the second vent; 1-3 represents the first injection port; 3 represents the lower casting mold; 3-1 represents the third vent; 3-2 represents the fourth vent; 3-3 represents the second injection port; 4 represents the intermediate casting mold; 4-1 represents the fifth vent; 4-2 represents the sixth vent; and 4-3 represents the third injection port.
[0026] Figure 6D shows the fabrication process of the injection cavity in the puncture replacement block in Example 1;
[0027] Figure 7 shows a photograph related to the surgical simulation process of medical isolation adhesive puncture and injection using a female pelvic model in Example 1;
[0028] Figure 8 shows CT images involved in the surgical simulation of the female pelvic model in Example 1;
[0029] Figure 9 is a three-dimensional structural diagram of the hard paraffin core in Example 1;
[0030] Figure 10 is a tooling structure diagram of the hard paraffin core and PC external casting mold in Example 1. Detailed Implementation
[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.
[0032] To make the objectives, process conditions, and advantages of the present invention clearer, the present invention will be further described in detail with reference to the following embodiments. However, the embodiments of the present invention are not limited thereto. Various substitutions and modifications can be made based on common technical knowledge and conventional means in the art without departing from the above-described technical concept of the present invention, and all such substitutions and modifications should be included within the scope of the present invention. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0033] The following examples use some of the raw materials from which the following sources were obtained:
[0034] The liquid silicone is food-grade liquid silicone, and its mechanical properties after curing are as follows: Material density: 1.1 g / cm³ 3 Hardness (Shore A): 30A; Tensile strength: 4.5±0.5MPa; Elongation at break: 350%; Tear strength: 12±2KN / m. This liquid silicone material, after curing, can more realistically simulate the feeling of vaginal wall puncture. Ordinary 3D printing cannot directly print silicone models of this strength.
[0035] Barium sulfate, CAS: 7727-43-7, purchased from Aladdin;
[0036] The hard paraffin was purchased from Shanghai Better Chemical Co., Ltd., and the type was No. 54 paraffin with a melting point range of 54 to 56°C.
[0037] Example 1: Fabrication of a pelvic organ group module
[0038] 1. Three-dimensional reconstruction of female pelvic organ system based on medical images
[0039] As shown in Figure 5, based on desensitized CT data and combined with knowledge of pelvic anatomy, 3D Slicer version 4.10.1 was used to convert the CT scan data into triangular patch format files for manual segmentation and 3D reconstruction of the female pelvic organ group. The pelvic region was displayed by cropping, and the cavities of the bladder, uterus, rectum, urethra, and vagina were selected using the thresholding function. The generated model was then imported into Blender software for sculpting to fit the pelvic framework. The digital soft tissue model was imported into Autodesk Fusion 360 version 2.0.6263 for mold creation.
[0040] 2. Design and fabrication of the pelvic organ system module
[0041] In this embodiment, the pelvic organ group module is fabricated using the silicone perfusion method. The specific steps are as follows:
[0042] ① Making the external casting mold: Use PC material 3D printing machine to make the PC external casting mold. The gray part in Figure 10 is the structure of the PC external casting mold. The inner surface of the mold is polished.
[0043] ② Fabrication of Pelvic Organ Paraffin Wax Cores: First, based on 3D data, 3D print the casting mold for each pelvic organ core using a high-precision 3D printer. The mold surface is sandblasted to remove printing textures, and then electroplated and polished to ensure a smooth surface. After mold assembly, the core mold is heated to 70 degrees Celsius and held at that temperature for two hours. Then, hard paraffin wax is heated and melted, poured into the core mold, and placed back into the heating device for slow cooling, controlling the temperature drop to 20-25 degrees Celsius every half hour. After cooling to room temperature and allowing the hard paraffin wax to completely cool, the mold is demolded, and the hard paraffin wax core is removed as shown in Figure 9. The hard paraffin wax core includes a paraffin wax core in the shape of a puncture replacement block, which facilitates the insertion space of the puncture replacement block after subsequent demolding. The pelvic organ paraffin wax core also includes a fixing block for fixing the organ paraffin wax model. The fixing block also has positioning holes for assembling the entire pelvic organ paraffin wax core with the outer casting mold. Hard paraffin wax is stronger than regular paraffin wax, making it easier to assemble and subsequently mold.
[0044] ③ Fabrication of the pelvic organ group module: As shown in Figure 10, assemble the external casting mold and the pelvic organ paraffin core according to the position of the positioning hole. After fixing the pelvic organ paraffin core, inject liquid silicone into the casting hole of the external casting mold using a liquid silicone equipment. Place it in a heating device with humidity less than 55% and temperature of 30 degrees for six hours until the silicone cures and then demold.
[0045] Because of the complex structure of the model, the commonly used physical demolding method cannot completely demold it, as it would damage the bladder and uterine structures inside the silicone model. Therefore, the model is demolded by heating it to 100 degrees Celsius to completely melt and flow out the hard paraffin core, thus obtaining a complete pelvic model.
[0046] 3. Design and fabrication of puncture replacement blocks
[0047] Fabrication of PC upper, middle, and lower casting molds: PC material upper casting mold, middle casting mold, and lower casting mold are fabricated using a PC material 3D printer. The inner surfaces of the molds are polished. As shown in Figure 6A, the upper casting mold 1 has a first vent 1-1, a second vent 1-2, and a first injection port 1-3; the lower casting mold 3 has a third vent 3-1, a fourth vent 3-2, and a second injection port 3-3; and the middle casting mold 4 has a fifth vent 4-1, a sixth vent 4-2, and a third injection port 4-3.
[0048] To better distinguish the posterior vaginal wall and anterior rectal wall under CT scans and to facilitate observation of puncture and injection sites, this preferred embodiment 1 uses CT-enhancing material approximately 1 mm from the posterior vaginal wall and approximately 1 mm from the anterior rectal wall in the replacement block. The material is a homogeneous mixture of liquid silica gel and barium sulfate. As shown in Figure 4, the arrows indicate the CT-enhanced layer of the anterior rectal wall; similarly, the posterior vaginal wall also contains a CT-enhanced layer approximately 1 mm from the anterior rectal wall.
[0049] Specifically, the steps for creating a replacement block with a developing layer are as follows:
[0050] As shown in Figure 6A, the upper casting mold 1, the middle casting mold 4, and the lower casting mold 3 are assembled. The manufacturing process involves a total of five casting operations. Each casting operation requires curing before the next casting operation. The curing conditions for each operation are as follows: the mold is placed in a heating device with humidity less than 55% and temperature of 30 degrees Celsius for six hours to allow the silicone to cure. The first casting involves injecting pure liquid silicone through the third injection port 4-3. After the silicone has cured, as shown in Figure 6B, the mold is placed with the upper casting mold 1 facing upwards, and the lower casting mold 3 is then injected from the third injection port 4-3. The second pouring is completed by injecting developing silicone through injection port 1-3. After the silicone has cured, a small amount of pure liquid silicone is injected through injection port 1-3 to completely cover the developing silicone layer, thus completing the third pouring. After the silicone has cured, as shown in Figure 6C, the mold is placed with the lower pouring mold 3 facing upwards, and developing silicone is injected through injection port 3-3 to complete the fourth pouring. After the silicone has cured, a small amount of pure liquid silicone is injected through injection port 3-3 to completely cover the developing silicone layer, thus completing the fifth pouring. Demolding is then performed.
[0051] After demolding, the one-piece molded silicone block is cut at position A on the side as shown in Figure 6D. A space is reserved by cutting horizontally along the direction of the dotted arrow. This space will serve as the injection cavity for injecting hydrogel into the replacement puncture block laterally. The cutting depth should not exceed 5cm and the width should not exceed 1.5cm. The cut at position A is sealed with a small amount of liquid silicone as a silicone adhesive. That is, the crack in area B, as shown in Figure 6D, is sealed. Because the liquid silicone used to bond the side opening is the same type of silicone as the liquid silicone used to make the replacement block, the silicone has a certain "self-healing" ability after curing. It becomes one with the original silicone material and will not affect the next puncture test.
[0052] Example 2: Assembly of a female pelvic model
[0053] Based on the actual human anatomical structure, the pelvic organ group module and puncture replacement block prepared in Example 1 are assembled together with the pelvic model and assembled into a female pelvic model inside the model shell.
[0054] Experimental example: Using a model for surgical simulation training
[0055] Experimental verification of CT-guided transvaginal posterior fornix puncture with medical isolation adhesive is shown in Figure 7. The surgical simulation of CT-guided transvaginal posterior fornix puncture with medical isolation adhesive was performed. Specifically, it included the following:
[0056] ①Prepare puncture items: As shown in Figure 7(a), prepare the puncture needle, needle mold, complete and unbroken replacement block, and hydrogel-containing double syringe. The needle mold serves as a guide for vaginal wall puncture. Its structure and materials are referenced from the patent document with publication number CN220175206U. Insert the replacement block into the female pelvic cavity model. The model after installation is shown in Figure 7(b).
[0057] ② As shown in Figure 7(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 image corresponds to Figure 8(a).
[0058] ③ Push the puncture needle into the rectovaginal septum and perform another CT scan to confirm that the needle tip has fully entered. The CT scan image corresponds to Figure 8(b).
[0059] ④ After injecting 0.5ml of normal saline, a CT scan was performed to ensure that the liquid could be smoothly injected into the rectovaginal septum. The CT scan image corresponds to Figure 8(c).
[0060] ⑤ As shown in Figure 7(d), inject 2ml of biological isolation gel using a dual syringe. After the gel solidifies, perform another CT scan to confirm the injection effect. The CT scan image corresponds to Figure 8(d).
[0061] ⑥ First remove the puncture needle, then remove the needle track mold;
[0062] The surgical simulation training experiment shows that the simulation model has good realism and operability in the experiment of transvaginal posterior fornix puncture of medical isolation adhesive under CT guidance, and can be used for repeated puncture practice; it is beneficial to improve relevant clinical skills and understanding of relevant knowledge.
Claims
1. A CT-guided posterior fornix vaginal puncture and injection module for pelvic organ groups, characterized in that, The pelvic organ module is a silicone module containing pelvic organ cavities, including the bladder and urinary tract connected to the bladder, the uterus and vagina connected to the uterus, and the rectum in the female pelvis. The pelvic organ module also includes a separable puncture replacement block, which is a replacement block composed of the lower half of the vaginal cavity wall from the vaginal opening to the posterior fornix of the vagina and the upper half of the rectal cavity wall adjacent to this lower half of the vaginal cavity. The puncture replacement block also has a reserved injection cavity for hydrogel, which is located between the posterior fornix of the vagina and the rectal wall.
2. The pelvic organ group module as described in claim 1, characterized in that, The silicone is food-grade liquid silicone, and the mechanical properties of the cured food-grade liquid silicone must meet the following conditions: material density of 1.1~1.16g / cm³. 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 as described in claim 2, characterized in that, The food-grade silicone is hydroxyl-terminated polyphenylsiloxane, dihydroxy polydimethylsiloxane, or the silicone material provided in the patent document with publication number CN108329694B.
4. The pelvic organ group module as described in claim 2, characterized in that, The mechanical properties of the food-grade silicone meet the following conditions: hardness 30A; tensile strength: 4.5±0.5MPa; elongation at break: 350%; tear strength: 12±2KN / m.
5. The pelvic organ group module as described in claim 1, characterized in that, The inner surface of the lower vaginal cavity wall and the upper rectal cavity wall of the puncture replacement block, or within 1 mm of the inner surface, is uniformly doped with CT-detectable material.
6. The pelvic organ group module as described in claim 5, characterized in that, The developable material is barium sulfate.
7. A female pelvic model, the female pelvic model comprising: The model shell, the pelvic module, and the pelvic organ group module as described in claim 1; The pelvic organ group module and the pelvic module are assembled and placed in the model shell; The model's outer shell is a plastic shell whose exterior shape matches the shape of a female pelvic cavity structure.
8. A method for manufacturing the pelvic organ group module according to claim 1, wherein the manufacturing method comprises the following steps: Three-dimensional reconstruction of the female pelvic organ system based on medical images; The creation of a female pelvic cavity model; Fabrication of a replacement block via transvaginal posterior fornix puncture; Based on the actual anatomical structure of the human body, the main pelvic cavity and the puncture replacement block are assembled into a pelvic organ group module.