WO2025105447A1 - Transparent ventricular model - Google Patents

Abstract

[Problem] To provide a cerebral model for training in endoscope surgery for treating a ventricular system disease, and a training method therefor. [Solution] A human cerebral model formed from a transparent synthetic resin and having an approximately spherical shape, the human cerebral model being formed by providing spaces, which correspond to right and left lateral ventricles, an interventricular foramen (Monro foramen), a third ventricle, a cerebral aqueduct, and a fourth ventricle in a human ventricular system, in a central portion of the approximately spherical shape.

Description

Transparent ventricle model

The present invention relates to a transparent ventricular model and a training device that can be used for training in endoscopic surgery to treat ventricular diseases.

The ventricles (also called the ventricular system) are complex-shaped cavities in the center of the cerebrum that are filled with cerebrospinal fluid. Cerebrospinal fluid is produced in a tissue called the choroid plexus, which is believed to be located in the left and right lateral ventricles, the third ventricle, and the fourth ventricle that make up the ventricular system. Most of the choroid plexus is located in the left and right lateral ventricles, and the cerebrospinal fluid produced mainly travels from the third ventricle to the fourth ventricle via the cerebral aqueduct. It then flows out into the subarachnoid space from the median and lateral foramen in the fourth ventricle. The cerebrospinal fluid that flows out into the subarachnoid space is absorbed by arachnoid granules in the arachnoid membrane and enters the venous system. The amount of cerebrospinal fluid in the ventricles and subarachnoid space is about 150 ml in adults, and the amount produced by humans per day is about 500 ml.

When stenosis or blockage occurs in the third ventricle, cerebral aqueduct, fourth ventricle, or the median or lateral foramen of the fourth ventricle, the ventricular system in front of the cerebrospinal fluid expands into the ventricles upstream of the blockage. The main causes of blockage are intraventricular tumors, pineal tumors, posterior fossa tumors, and intracerebral hemorrhage. When the above conditions occur, the pressure inside the ventricles increases, causing symptoms such as headache, nausea, vomiting, papilledema, optic atrophy, and impaired consciousness, and the condition is diagnosed as hydrocephalus.

Endoscopes are used in the surgical treatment of intraventricular diseases, such as hydrocephalus. Because the ventricles have a complex structure, determining which part of the ventricular system the tip of the endoscope touches and whether it is reaching the right part while avoiding parts that should not be touched often depends on the doctor's skill.

In the 1980s and 1990s, endoscopic treatment became widespread. However, there were no suitable models of complex organs for endoscopic practice. Until the mid-1990s, cadavers were often used for endoscopic training. For example, in training for ventricular endoscopy, an endoscope was inserted into the head of a donated cadaver, and after training, the brain was divided to verify how the endoscope moved inside the brain. Later, with the development of synthetic resin processing technology, medical models that imitated the brain also came to be used, but there was no model that had the function of checking from a bird's-eye view how the endoscope actually moved.

For example, Patent Document 1 describes a transparent brain model. Although it has a hollow structure, it is a model for calibrating a tomographic imaging device, and is not designed to resemble the hardness or structure of the human body for surgical training.

Furthermore, medical models of the ventricular system in particular must realize a complex hollow structure inside the brain, a tissue so soft that it would be crushed under its own weight. For this reason, in an attempt to closely resemble the actual shape, there are models that have been created with the hollow parts removed, as in Non-Patent Document 1, but there have been no medical models that mimic the actual human ventricular system and allow the operator to view the surgical conditions from the outside.

JP 2008-132022 A

https://www.3bs.jp/manual-download/VH410.pdf

As mentioned above, there has not been a surgical training model that closely resembles the texture of the actual human cerebrum and faithfully reproduces the ventricular system, while allowing the movement of tools such as endoscopes to be visually observed from the outside.

As a result of thorough investigation of the above problems, the inventors discovered that a human cerebral model made by using a 3D printer to create a mold with a hollow structure of the human ventricular system, pouring a specific transparent resin into it and letting it harden, allows surgical tools such as an endoscope to be easily viewed from the outside, and is therefore useful for practicing surgery, developing new surgical methods, and obtaining informed consent from patients, which led to the completion of the present invention.

The present invention therefore provides the following:

One embodiment of the present invention is a human cerebral model [1] made of a transparent synthetic resin and having a roughly spherical shape, with spaces in the center of the roughly spherical shape corresponding to the left and right lateral ventricles, the interventricular foramen (foramen of Monro), the third ventricle, the cerebral aqueduct, and the fourth ventricle in the human ventricular system.

Another embodiment of the present invention is the above-described human cerebrum model, [2] in which the human cerebrum model is divided at a predetermined position.

Another embodiment of the present invention is the human cerebrum model described above, [3] in which the human cerebrum model is divided into upper and lower halves at the height of the posterior horn of the lateral ventricle.

In another embodiment of the present invention, [4] the lateral ventricle, the third ventricle, or the fourth ventricle further includes a region simulating a choroid plexus.
This is the human cerebral model described above.

Another embodiment of the present invention is the above-described human cerebral model, [5] which has a roughly spherical area corresponding to the pineal gland located below the third ventricle and slightly above the inferior horn of the lateral ventricle.

Another embodiment of the present invention is the above-described human cerebrum model, in which [6] the bisected human cerebrum model is fixed.

Another embodiment of the present invention is a ventricular system endoscopic training device comprising: [7] a human cerebral model formed from a transparent synthetic resin and having a roughly spherical shape, with spaces corresponding to the left and right lateral ventricles, the interventricular foramen (foramen of Monro), the third ventricle, the cerebral aqueduct, and the fourth ventricle in the human ventricular system at the center of the roughly spherical shape; and a partially open transparent container.

Another embodiment of the present invention is the above-described ventricular endoscopy training device, [8] in which the container is provided with a fixing device for the human cerebrum model.

Another embodiment of the present invention is the above-described ventricular endoscopy training device, [9] in which the human cerebral model is divided into two halves at the height of the posterior horn of the lateral ventricle, the two halves of the human cerebral model are fixed with a rod passing through them, and the fixing device has a structure for engaging the end of the passing rod.

Another embodiment of the present invention is the above-described ventricular endoscopy training device, [10] in which the container is filled with a transparent liquid.

Another embodiment of the present invention is the above-described ventricular endoscopy training device, further comprising a sheath having a portion that is visible from the outside when it is passed through the human cerebrum model inside the container.

Another embodiment of the present invention is the human cerebrum model described above, in which [12] the movement target of the endoscope or the area to be avoided by contact or invasion of the endoscope is color-coded.

　According to the present invention, the movement of an endoscope inside the brain can be observed from the outside during brain surgery. Therefore, it is suitable for training students and doctors in ventricular surgery by using multiple people to observe and record. Furthermore, since it is possible to visually check the whole and details of the brain from the outside and various insertion patterns of surgical tools can be considered, it is useful for research and development of approaches to treatment sites. Furthermore, since the movement of surgical tools can be visually checked from the outside, it is also useful for validation of endoscopes, etc. Furthermore, it can also be used when doctors explain surgical schemes and treatments for diseases to patients.

FIG. 1 shows the human ventricular system from the left side of the head. FIG. 1 shows a parietal view of the human ventricular system. FIG. 1 is a schematic diagram of the human cerebral model described herein. FIG. 1 shows a schematic diagram of the internal structure of the human cerebrum model described herein. FIG. 1 illustrates one embodiment of a container in a training device described herein. FIG. 1 illustrates one embodiment of the use of the training device described herein. FIG. 1 illustrates one embodiment of the use of the training device described herein. FIG. 1 illustrates one embodiment of the use of the training device described herein.

The ventricular model and ventricular endoscopy training device described in this specification are explained in more detail below with reference to the drawings. However, this is not intended to limit the ventricular model and ventricular endoscopy training device described in this specification in any way.

First, an overview of the human ventricular system will be described with reference to Figures 1 and 2. The ventricular system is the part through which cerebrospinal fluid flows in the brain, and is composed of the anterior horns A of the left and right lateral ventricles, the lateral ventricles B, the interventricular foramen J, the third ventricle E, the cerebral aqueduct H, and the fourth ventricle F. The left and right lateral ventricles B are located in the cerebrum, and the lateral ventricles are part of the ventricular system and are the places where cerebrospinal fluid is produced. The left and right lateral ventricles B are located inside the cerebrum. The interventricular foramen J (also called the foramen of Monro) is a passage that connects the left and right lateral ventricles B and the third ventricle E. The cerebrospinal fluid produced in the lateral ventricle B flows into the third ventricle E through the interventricular foramen J. Next, the third ventricle E receives cerebrospinal fluid from the lateral ventricle B through the interventricular foramen J. This part is located between the thalamus and the hypothalamus. The cerebral aqueduct H is a long and narrow passage that connects the third ventricle E and the fourth ventricle F, and runs vertically through the brain stem. Cerebrospinal fluid flows through this aqueduct into the fourth ventricle F. Next, the fourth ventricle F is located between the cerebellum and the brain stem, and cerebrospinal fluid flows into it through the cerebral aqueduct. From the fourth ventricle F, it flows out of the brain, filling the subarachnoid space, and also flows into the spinal cord via the central canal G.

The choroid plexus, which is responsible for the production of cerebrospinal fluid, is present in the left and right lateral ventricles B, the third ventricle E, and the fourth ventricle F (not shown in Figures 1 and 2). The choroid plexus is generally irregular in shape and has many hair-like projections. These projections are composed of blood vessels and epithelial cells, and the cells are tightly bound to the surrounding capillaries. The cerebrospinal fluid secreted from the choroid plexus physically protects the brain and spinal cord, maintains the balance of nutrients and chemicals in the brain, and flows to each part of the brain through the ventricular system. Note that Figures 1 and 2 are written for the purpose of explaining the ventricular system, and in the human cerebral model of the present invention, such a ventricular system is molded as a hollow structure in an approximately spherical shape made of transparent synthetic resin.

The transparent ventricle model of the present invention uses a transparent synthetic resin to model the ventricles, which play such a complex and important role, making it possible to visually understand their complex internal structure. It is particularly important to understand structures such as the ventricular system and choroid plexus in three dimensions, but it is difficult to directly visualize these three-dimensional structures using regular MRI or CT scans.

Next, the human cerebrum model 1 in this specification will be described with reference to Figure 3. Figure 3 is a view of the human cerebrum as seen from the front and slightly below. In Figure 3, the outline of the part corresponding to the ventricular system is indicated by a dotted line. The human cerebrum model in this invention is composed of a base material 3 made of a transparent synthetic resin, and as shown in Figure 1, 5, the shape corresponding to the ventricular system part has a hollow structure.

The transparent synthetic resin used in the transparent ventricle model of the present invention should be capable of reproducing the flexibility of the human cerebrum to a certain extent, and should be transparent enough to allow its internal structure to be visible from the outside without being partially deformed or destroyed by its own weight. Furthermore, since it will be used by fixing it in a container filled with a transparent liquid as described below, it is preferable that it has resistance to leaching by various liquids. Furthermore, it is preferable that the resin can maintain its shape even when a rod or the like is pierced to fix it to a fixing tool, and that it can maintain the above-mentioned favorable properties even when the rod used for fixation is pierced in a different position many times.

Such resins are not particularly limited, as long as they are synthetic resins whose transparency and elasticity can be adjusted to a certain degree by additives or crosslinking. Specific examples include ABS resin, polyethylene, polystyrene, epoxy resin, acrylic resin, phenolic resin, polyamide, polybutylene, polycarbonate, polyester, polyurethane, polyvinyl chloride, silicone rubber, etc., but from the perspective of achieving a texture similar to that of the human brain, polyurethane and silicone rubber are preferred, with polyurethane being particularly preferred.

Polyurethane is a general term for polymers that contain urethane bonds, and is usually produced by polyaddition of compounds that contain isocyanate groups and hydroxyl groups. Non-foamable elastomer materials are preferred as the polyurethane used in the present invention.

Polyurethane is very suitable for the human cerebrum model of the present invention due to its excellent properties such as transparency, flexibility, heat resistance, and chemical resistance. Furthermore, polyurethane itself retains its properties for a long period of time, making it possible to create very detailed models. In particular, the flexibility of polyurethane is a great advantage when creating a model with a complex shape such as a brain. This is particularly suitable for cases where a real feel is important, such as surgical practice and pre-operative planning. Polyurethane has flexibility that reproduces the flexibility of the human cerebrum, and when surgical tools such as sheaths and endoscopes are inserted, operability close to that of an actual operation can be achieved, while the resin itself is transparent, so the movement of the surgical tools inside the brain can be confirmed from the outside. This is particularly useful for surgical practice and pre-operative planning.

As shown in FIG. 4, the human cerebrum model in this specification is divided into two parts, upper and lower, horizontally at the position of the posterior horn C of the lateral ventricle of the ventricular system, in which the cerebrum part molded with transparent synthetic resin is formed. In this embodiment, the upper part is called the upper hemisphere 6 and the lower part is called the lower hemisphere 7. By configuring it in this way, it is possible to explain the treatment of the ventricular system while confirming the subdivision of the ventricular system, and to confirm which part the endoscope is in contact with after training in the procedure. In this invention, the division position of the human cerebrum model can be changed appropriately depending on the purpose of use. In addition, since the divided human cerebrum model in this invention is held in a transparent container described later, it is preferable that it is fixed by a suitable means. In the embodiment described in this disclosure, it is fixed by penetrating a rod, but it may be possible to lock it by the frictional force of the resin surface, or it may be fixed using tape or another locking device.

Furthermore, as shown in FIG. 4, the human cerebrum model in this specification further comprises an area simulating a choroid plexus 8 in any or all of the areas from the lateral ventricles to the third and fourth ventricles. Although the cerebrum model of the present invention is made of a transparent synthetic resin, such areas may be colored. Alternatively, a separate, pre-colored member may be placed in the lateral ventricles, third ventricle, and fourth ventricle as the choroid plexus. When the choroid plexus 8 is a separate member, it is preferable that it is made of a water-resistant member, since the training device of the present invention is operated in a transparent liquid such as water, as described below.

By configuring it in this way, when training on surgical tools such as endoscopes, it is possible to check from the outside whether choroid plexus cauterization (CPC) or choroid plexus resection (CPR) is being performed accurately while checking the operation of the surgical tool.

In addition, the human cerebral model in this specification can further have a roughly spherical part 4 (Figure 3) corresponding to the pineal gland located below the third ventricle and slightly above the inferior horn of the lateral ventricle. The location of such important parts that should be avoided from contact and the large

In other words, the ventricular system model of the present invention may be color-coded to indicate contact areas or areas to avoid invasiveness during surgery. For endoscopic training, it is also effective to color the areas and routes that serve as the movement targets of the endoscope. The colored areas may be colored after molding the cerebral model, or separate parts colored for each area may be joined after molding. By using a separate material for the areas to avoid invasiveness, their positions can be recognized from the outside during surgical tool training, and they can also be confirmed by touch with the endoscope, etc.

Next, the intraventricular endoscope training device according to the present invention will be described with reference to FIG. 5. This specification provides an endoscope training device that includes the above-mentioned cerebral model and a partially open transparent container. An example of such a transparent container is a so-called cubic transparent container. Since the cerebral model of the present invention is approximately spherical, it is necessary to fix the cerebral model in place, for example, in endoscopic training. It is preferable to align the head with the direction of actual surgery. Therefore, the human cerebral model 1 of the present invention can be fixed to a support base 12 in a transparent container 10 shown in FIG. 5 and used for endoscopic training. By placing the human cerebral model 1 in the transparent container 10 and fixing it to the support base 12, it is possible to fix the head in a direction that mimics actual surgery and perform surgical training. In the embodiment shown in FIG. 5, the support base 12 is configured by providing a hook portion 12b with a bent tip on the upper part of a base 12a that is approximately U-shaped with an inclined surface, but it is not intended to limit the support base of the present invention to such a shape, and the shape of the support base can be changed as appropriate.

Next, referring to FIG. 6, an embodiment in which the human cerebrum model in this specification is placed in a transparent container 10 will be described. When using such a container, it is preferable to fill the container with water 15 or the like so that the cerebrum model is immersed. In the present invention, the liquid filling the transparent container may be a transparent liquid other than water, and can be appropriately selected in consideration of compatibility with the resin used in the cerebrum model part from the viewpoint of elution and refractive index of light. By configuring it in this way, it is possible to mimic the state of the brain floating in cerebrospinal fluid. In addition, by using polyurethane with a refractive index very close to that of water, the transparency of the cerebrum model appears to increase when the cerebrum model is placed in water. For this reason, the present invention is particularly suitable for confirming surgical tool training and surgical tool movement.

Furthermore, in FIG. 6, the bisected human cerebrum model can be fixed with a fixing device 13. In the embodiment of FIG. 6, the fixing device is a rod-shaped fixing device 13. A hole 9 for passing the rod-shaped fixing device 13 through may be provided in the human cerebrum model beforehand as shown in FIG. 4, or since the cerebrum model itself is made of a flexible material that mimics the tissue of the cerebral cortex, it may be fixed by inserting a rod into the desired position. In view of the object of the present invention, it is preferable that the rod-shaped fixing device 13 and the transparent container 10 used to fix the cerebrum model are hard materials made of transparent resin. Examples of such resins include, but are not limited to, acrylic resin, polycarbonate resin, polyester resin, polypropylene resin, polystyrene resin, polyurethane resin, and polyvinyl chloride resin.

The support base 12 is composed of a base 12a that can be inclined and placed inside the transparent container 10, and a hook portion 12b for fixing the human cerebrum model 1, which is fixed with a number of rod-shaped fixing devices 13, to the base 12a. By adjusting the inclination angle of the base 12a, the head position during training can also be changed.

Next, referring to FIG. 7, the intraventricular system endoscope training device of the present invention also includes a sheath 16 with a colored tip for, for example, endoscope training. By using such a sheath, the approach of the surgical tools to the ventricular system can be confirmed from the outside.

Next, referring to Figure 8, an embodiment in which an endoscope is inserted in the intraventricular endoscopic training device according to the present invention will be described. As shown in Figure 8, the sheath 16 is inserted at the desired position, and the endoscope is inserted using this as a guide. In this embodiment, it is possible to confirm from the outside where the tip of the endoscope is located and how it is moving. Specifically, if the insertion angle or operation of the endoscope (not shown) is moved roughly, it is possible to observe not only the tip of the endoscope but also the endoscope body moving in a wavy manner while pushing against normal structures.

The human cerebrum model of the present invention can be molded by pouring the aforementioned suitable resin as a molten resin into a mold. The manufacturing method of such a mold is within the knowledge of a person skilled in the art, but in the present invention, it can be designed and manufactured using 3D CAD based on image data of the human cerebrum taken by MRI or CT. If the cerebrum model is divided into upper and lower halves at the height of the posterior horn of the lateral ventricle, manufacturing is facilitated by using a roughly hemispherical injection molding mold with a molded recess corresponding to the ventricular system portion.

The human cerebral model of the present invention and the intraventricular endoscopic training device using the same make it easy to confirm where surgical tools are located in the brain and how they move. Therefore, from an educational point of view, it is useful for medical students and medical professionals to perform surgical training while visually understanding the internal structure of the brain. In addition, from the perspective of diagnosis and treatment planning, it is useful for understanding specific brain diseases and disorders and formulating treatment plans for them. It can also be used as a reference model for pre-operative planning and during surgery. Furthermore, it is useful for doctors to explain to patients and their families the nature and location of diseases, the parts of the brain that are affected, and treatment methods.

A: Anterior horn of the lateral ventricle
B: Lateral ventricle C: Posterior horn of the lateral ventricle D: Inferior horn of the lateral ventricle E: Third ventricle F: Fourth ventricle G: Central canal H: Cerebral aqueduct I: Interthalamic bridge J: Interventricular foramen 1: Human cerebral model 3: Base material 4: Colored part corresponding to the pineal gland 5: Cavity corresponding to the ventricular system 6: Upper hemisphere 7: Lower hemisphere 8: Choroid plexus model 9: Hole 12: Support 12a: Base 12b: Hook 13: Rod-shaped fixture 15: Water 16: Sheath 18: Endoscope

Claims (12)

In a roughly spherical human cerebrum model made of transparent synthetic resin,
The approximately spherical central portion is provided with spaces corresponding to the left and right lateral ventricles, the interventricular foramen (foramen of Monro), the third ventricle, the cerebral aqueduct, and the fourth ventricle in the human ventricular system.
Human brain model. The human cerebrum model according to claim 1, wherein the human cerebrum model is divided at a predetermined position. The human cerebral model is divided into upper and lower halves at the height of the posterior horn of the lateral ventricle.
3. The human cerebral model according to claim 2. Further comprising a site simulating a choroid plexus in any or all of the lateral ventricle, the third ventricle, or the fourth ventricle;
The human cerebral model according to claim 1. The human cerebrum model according to claim 1, in which a roughly spherical area corresponding to the pineal gland is provided below the third ventricle and slightly above the inferior horn of the lateral ventricle. The human cerebrum model according to claim 2 or 3, wherein the bisected human cerebrum model is fixed. A roughly spherical human cerebral model made of transparent synthetic resin.
a human cerebral model having spaces corresponding to the left and right lateral ventricles, the interventricular foramen (foramen of Monro), the third ventricle, the cerebral aqueduct, and the fourth ventricle in the human ventricular system in the central part of the approximately spherical shape;
A partially open transparent container;
Ventricular endoscopy training device. The ventricular endoscopy training device according to claim 7, wherein the container is provided with a fixture for fixing the human cerebrum model. The human cerebrum model is divided into upper and lower halves at the height of the posterior horn of the lateral ventricle,
The bisected human cerebrum model is fixed with a rod passing through it,
The fastener has a structure for locking an end of the through rod.
The ventricular endoscopy training device according to claim 8. The ventricular endoscopy training device of claim 7 further comprises a transparent container filled with a transparent liquid. The ventricular endoscopy training device according to claim 7 further includes a sheath having a portion that is visible from the outside when it is passed through the human cerebrum model in the container. 2. The human cerebrum model according to claim 1, wherein a moving target of the endoscope or a contact or invasion avoidance site of the endoscope is color-coded in said human cerebrum model.