JPH0511689A - Manufacture of solid model of internal organ or the like - Google Patents

Abstract

PURPOSE:To manufacture the solid model in substantially the same structure with the actual organ of a living body to the extent of its internal structure. CONSTITUTION:Photosetting resin is irradiated with laser light according to two-dimensional sectional image data obtained by a sectional shape measuring instrument for the internal organs, etc., to form set layers conforming with respective sectional shapes, and those layers are laminated in order to form the solid model.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a three-dimensional model of internal organs and organs such as a human body. The present invention relates to a method for manufacturing a three-dimensional model by an optical molding method.

[0002]

2. Description of the Related Art In recent years, CT has been used in the field of medical equipment.
(Computed tomography), ultrasonic diagnostic equipment and the like have come to be generally used in the field of examination / diagnosis of diseases of internal organs and organs of the human body, pregnancy and the like.

According to these diagnostic devices, the human body can be diagnosed with little or no invasion. Moreover, in the conventional simple X-ray imaging, all the tissues and organs in the X-ray direction of the imaging region are shown on a single film in a state of being overlapped, but in the X-ray CT apparatus and the ultrasonic diagnostic apparatus, the Since it is possible to obtain a three-dimensional tomographic image, more useful examination information can be obtained.

By the way, for example, when performing surgery,
It is important to know the positional relationship between lesions and organs. Also,
Radiation therapy requires irradiation of the entire three-dimensional lesion. However, in the conventional scanning method using these devices, the information of the tomographic structure can be obtained only in two dimensions, and the positional relationship between the affected part, which is the measurement target, and other internal organs and organs. Was difficult for the doctor to recognize. Therefore, a method has been attempted in which a plurality of CT images are photographed and viewed as three-dimensional, or a positional relationship between a surgical site and another site is grasped by displaying a three-dimensional image, but it is still insufficient.

Recently, in order to solve this problem, the two-dimensional information of the tomographic plane obtained by the above-mentioned tomography method is re-analyzed into three-dimensional information, and a linear movement type three-dimensional display is based on the re-analyzed information. An epoch-making method of displaying a stereoscopic image by using the method has been proposed (Japanese Patent Laid-Open No. 61-212885).
According to this method, based on the two-dimensional image information, it is possible to visually recognize a three-dimensional stereo model that is similar to the real thing.

[0006] However, for example, in a surgical operation for removing an affected part such as liver cancer, the affected part is close to blood vessels, so that it may be fatal if the positional relationship between them is not accurately grasped. In addition, performing surgical resection of the affected area so as not to cause metastasis of the lesion is a major factor in successful surgery. Therefore, if, in addition to the information recognized in the three-dimensional image, an actual model having the same structure as the affected area (including internal tissues, organs, etc.) can be modeled, it is possible to more accurately recognize the affected area position. Moreover, since the surgery can be simulated, the probability of successful surgery can be increased.

As described above, if a system for forming an accurate three-dimensional model of internal organs and organs can be established, it is possible to quickly perform an operation for removing obstacles in various parts of the body such as a lesion. Such a three-dimensional model forming system enhances the probability of successful surgery if it is used not only in surgical operations for removing liver cancer and the like, but also in complicated fields such as excision of caries and oral lesions. Is very effective for. However, conventionally, no method has been proposed for accurately and promptly producing a three-dimensional model of a living body internal tissue such as a human body.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing a three-dimensional three-dimensional model having substantially the same structure as an actual body up to the internal organs and internal organs of a living body. Another object of the present invention is to provide a non-invasive method for producing a three-dimensional model of internal organs or organs without causing pain or affecting the human body.

As a result of intensive studies, the present inventors have found that various C
Using a two-dimensional tomographic image obtained by using a non-invasive device such as a T-device or an ultrasonic diagnostic device that can measure the tomographic shape of internal organs and organs, it is possible to manufacture an accurate three-dimensional model by optical modeling method. The present invention has been completed based on the findings and the findings.

[0010]

Thus, according to the present invention, the photocurable resin is irradiated with the laser beam based on the two-dimensional tomographic image data obtained by the tomographic shape measuring device for the internal or organs. There is provided a method for producing a three-dimensional model of internal organs or organs, which comprises forming a hardened layer conforming to each fault shape and sequentially stacking these to form a three-dimensional model.

The present invention will be described in detail below. The method for producing a three-dimensional model of internal organs or organs of the present invention specifically includes the following steps. First, a CT device, an ultrasonic diagnostic device, or the like is used to obtain shape information on a tomographic plane of a patient or a target human body.

Examples of the CT apparatus include an X-ray CT apparatus and a nuclear magnetic resonance CT apparatus. In CT, a tomographic image of a human body is obtained by digitizing projection information at each rotational position around the subject using a detecting means such as X-rays and processing by a computer to obtain a tomographic image of a human body sliced. ing.

As the ultrasonic diagnostic apparatus, there are an apparatus utilizing pulse ultrasonic waves, a high-speed scanning ultrasonic diagnostic apparatus, and the like. For example, when an ultrasonic pulse is emitted from a transducer while scanning an ultrasonic beam, a weak reflected signal (echo) from the boundary between tissues with different acoustic impedances returns to the transducer, but this echo is amplified. Then, there is a method of displaying in a waveform or a method of modulating the brightness and displaying it as an image.
The ultrasonic diagnostic apparatus used in the present invention preferably has excellent resolution. When the frequency is high, the obtained image becomes sharp, but the transmission length becomes short. Therefore,
It is preferable to use a high frequency one when the target part is close to the skin and a low frequency one when the whole body needs to be imaged.

In an image diagnostic apparatus such as X-ray CT or ultrasonic diagnostics, image information obtained by various sensors is recorded as a digital signal, subjected to image processing and converted into a video signal for display. For example, the tomographic data input by the ultrasonic sensor is usually recorded on a video tape while being monitored by a television. This image data is stored in the video memory in the computer in the form of a video signal.

The image stored in the video memory is displayed on a computer display and assigned by an expert to affected cells such as internal organ walls, blood vessels and cancer. This attribution is performed when cutting and repairing the displayed image. On the computer, the video data is modified according to this attribution. Specifically, for those classified as having the same attribution, the same numerical data is input to the video memory, and at the same time, these are expressed in the same color tone on the display, making it possible to distinguish from other parts. ..

Further, on the computer, the surface portion is automatically recognized, and the data in the video memory is rewritten so that the surface portion can be distinguished from the portion outside the surface. At this time, if the structure to be created in a later step is a part of the original structure or there is an unnecessary structure, these unnecessary data can be deleted by selection. Further, the operator performs the noise elimination, the addition of a bridge for maintaining the model structure shape, or the computer automatically performs.

In the correction operator processing of the two-dimensional tomographic shape, the noise elimination is performed in order to correct the adhesion of the spots and the shape distortion in the three-dimensional model forming due to the noise. The bridge addition for holding the three-dimensional model structural shape is performed, for example, for holding the three-dimensional model having a spatially floating structural portion at a desired position when modeling the three-dimensional model. The method is to add a bridge to the plane tomographic image data for the structural part in a spatially floating position so that it will eventually become a string-like shape so that its relative position does not change from other parts. By. Alternatively, add the data of the plane part corresponding to this edge in order to shape the affected part into a structure in which the edge is finally contained in a box formed of rod-shaped objects. The floating part can be prevented from coming off from the part connected to this edge. The two-dimensional plane tomographic image data obtained in this way is
It is molded into a three-dimensional solid model by the stereolithography method.

When the photocurable resin (uncured photopolymerizable reactive composition) is irradiated with light, the portion to which light energy is applied causes a polycondensation reaction to be cured. The curing range is a depth determined by the total irradiation amount and the photosensitivity of the resin with respect to the optical axis direction, and the cross-sectional shape of the irradiation light is substantially the same in the direction orthogonal to the traveling direction. Therefore, for example, a thin plate-shaped hardened layer can be obtained by irradiating the resin surface with a thinly focused light beam while scanning the resin surface. By laminating this cured layer, a three-dimensional object having a desired shape can be created.

Therefore, based on the two-dimensional tomographic image data, a photocurable resin is irradiated with a laser beam to form a hardened layer conforming to each tomographic shape, and these are sequentially laminated to form a three-dimensional model. Can be shaped.

As a laminating method, (1) a method of additionally supplying an uncured photocurable resin after curing of one layer is completed,
(2) 1 by submerging the base plate in the resin
Method of adding uncured resin for one layer onto the cured product (model sedimentation method), (3) irradiating light through the transparent plate, and when curing for one layer is finished, raise the transparent plate Method (4) Various methods such as irradiating light from the transparent lower part of the bath containing the photocurable resin and raising the base plate into the resin can be adopted.

Taking the settling method for a molded article as an example, a base plate is set just below the liquid surface of a bath (container) containing an uncured photocurable resin, and an ultraviolet laser beam is irradiated to cure the bottom layer. Then, the base plate is lowered by one layer to cure the next layer. This operation is repeated to perform modeling.

The laser light controls the irradiation position and irradiation on / off based on the two-dimensional tomographic image data.
The scanning method of laser light is not particularly limited. A table (3D N) with a fixed laser beam and a bath
C table) may be moved.

After completion of photo-molding, the three-dimensional model is taken out of the bath, and the remaining reactive composition (uncured photo-curable resin)
Is washed away with a solvent or the like, or is irradiated with ultraviolet rays to be cured to make it handleable.

Specific examples of the photocurable resin (reactive composition) utilizing the photoradical reaction used in the present invention include:
Monofunctional or polyfunctional acrylate and methacrylate compounds having epoxies, urethanes and polyethers as skeletons; various acrylate and methacrylate compounds having alkyl groups and aryl groups; vinyls having various unsaturated groups highly reactive with them Examples include a mixture to which a compound is added.

Specific examples of the photocurable resin utilizing the photocation reaction include monofunctional and polyfunctional compounds having an epoxy group.

Examples of the photopolymerization initiator used as the photoradical polymerization catalyst include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone (manufactured by Merck, trade name Darocur-2959); α-
Hydroxy-α, α'-dimethyl-acetophenone (manufactured by Merck, trade name Darocur-1173); acetophenone-based compounds such as methoxyacetophenone and 2,2-dimethoxy-2-phenylacetophenone; benzoin such as benzoin ethyl ether and benzoin isopropyl ether. Ether-based compounds; ketal-based compounds such as benzyl dimethyl ketal; and halogenated ketones, acylphosphinoxides, acylphosphonates and the like. Further, Michler's ketone-based, benzophenone-based, and thioxanthone-based photosensitizers can also be used in combination with amines and the like.

As the cationic photopolymerization catalyst, diazonium compounds, sulfonium compounds, iodonium compounds,
Examples thereof include metal complex compounds and aryl silanol-aluminum complexes.

A photosensitive compound is added to these resins, and a laser that emits light of other wavelengths in addition to the irradiation degree of the laser is installed to form a multi-tone color tone surface on the plane simultaneously with polymerization. It is possible to do it.

By creating a three-dimensional model of the affected area and its surroundings, doctors can recognize the shape of the affected area and the positional relationship with other organs by visual inspection or palpation. In some cases, surgery trials can be performed. Further, such a series of procedures can be performed before the surgery or in parallel with the surgery work.

[0030]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[Example 1] In order to create a stereoscopic image around the liver portal vein, first, an ultrasonic endoscope having a 3.5 MHz sensor is used to monitor the periphery of a target portion inside a patient. The image data was input to the video recorder. The data was A / D converted and then transferred to a video memory. The computer was made to recognize the affected part and the portal vein site in the two-dimensional tomographic image data for each plane, which was input from the data in this memory in an interactive manner with the computer. Parts other than these were cut. Further, in order to prevent the structural portion from falling into the reaction bath during modeling, a frame is formed around the target affected area, and the frame and the affected area are connected by a bridge.

The corrected tomographic image thus obtained is
It was corrected to an image in which a 255 × 255 image per surface was divided vertically and horizontally to form one square dot. The surface portion of this image was identified by computer calculation, and the memory data of that portion was rewritten. In this way, 255 per side
Planar image data of 255 color tones were obtained on a memory of a central processing unit (CPU) of 255 sheets.

The corrected two-dimensional tomographic image data is transferred to the stereo model producing device, and the photocurable resin is covered on one side (one cured layer).
The target solid model was created by repeating the process of irradiating a laser beam on each surface to form a pattern so that the thickness of the layer was 0.5 mm, and dipping the patterned hardened layer in a bath. In the obtained three-dimensional model, the positional relationship between the portal vein and the affected area was accurately recognized by the tentacles. FIG. 1 shows a schematic view of the appearance of the obtained three-dimensional model near the liver portal vein.

[0034]

INDUSTRIAL APPLICABILITY The three-dimensional model obtained by the manufacturing method of the present invention is extremely difficult to work as an auxiliary means for smoothly performing an operation on an affected part of an organ or an organ, and a slight deviation in work procedure. This is useful when is life-threatening.

As an application example of the three-dimensional model according to the present invention, for example, in the case of knowing the positional relationship between the mandible and the maxilla and the affected part in the treatment of teeth, the visceral cancer is in close proximity to an artery or the like which is troubled. However, there is a means for confirming the excision route in the case where the excision route is a key to the success of the operation, and it is possible to smoothly perform these operations.

Conventionally, doctors have been groping for the location of cancer, but this action can cause the metastasis of cancer to the normal site, which makes it difficult to treat the patient. ..

Furthermore, since the positional relationship between the affected part and other organs can be accurately recognized without removing the affected part, it is possible to give important knowledge to clinical research such as elucidation of the expression mechanism of cancer and the like. It is useful for deciding the treatment method for diseases requiring physical therapy such as spinal curvature and for recognizing changes in the healing state.

This is useful in cases where fractured sites such as complicated fractures overlap in a complicated manner and the position recognition is required during surgery.

[Brief description of drawings]

FIG. 1 is a schematic external view of a three-dimensional model near the liver portal vein obtained according to an example of the present invention.

[Explanation of symbols]

 1 Modeling direction 2 Modeling surface end

Claims (1)

Claims: 1. A photocurable resin is irradiated with laser light based on two-dimensional tomographic image data obtained by a tomographic shape measuring device for internal organs or organs, and each tomographic shape is matched. A method for producing a three-dimensional model of internal organs or organs, which comprises forming a hardened layer to form a three-dimensional model by sequentially stacking these layers.