WO2022206024A1

WO2022206024A1 - Internal tissue model construction method and terminal device

Info

Publication number: WO2022206024A1
Application number: PCT/CN2021/138022
Authority: WO
Inventors: 廖祥云; 王琼; 钱银玲; 王平安
Original assignee: 中国科学院深圳先进技术研究院
Priority date: 2021-03-29
Filing date: 2021-12-14
Publication date: 2022-10-06
Also published as: CN113160383B; CN113160383A

Abstract

An internal tissue model construction method and a device, applicable to the technical field of virtual simulation, the method comprising: acquiring scan data about an internal tissue of a target object, and generating a three-dimensional model of the internal tissue on the basis of the scan data (S101); constructing a tissue mechanical model for each of three-dimensional tissue models (S102); on the basis of the three-dimensional model, determining multiple model groups having adjacent relationships, and establishing contact force functions corresponding to the respective model groups (S103); and according to the three-dimensional model, the tissue mechanical models corresponding to the respective three-dimensional tissue models in the three-dimensional model, and all the contact force functions corresponding to the model groups, generating an internal tissue model corresponding to the internal tissue (S104). The internal tissue model constructed by the method can simulate and restore the internal tissue in a three-dimensional form, and the constructed virtual model can respond to interactive operations, thereby improving the simulation level of the model.

Description

A method for constructing an internal organization model and a terminal device

technical field

The invention belongs to the technical field of virtual simulation, and in particular relates to a method for constructing an internal organization model and a terminal device.

Background technique

With the development of computer technology, the application of virtual simulation technology has become more and more extensive, such as the application in the field of virtual surgery, which provides important guidance for the actual surgical process. Therefore, how to build a virtual scene that fits the actual situation, such as building a corresponding visual model for a real object in a simulation environment, has become the key to virtual simulation technology.

In the process of simulating the internal tissue, the fidelity of the internal tissue model constructed in the process of responding to interactive operations, such as responding to pressing, puncturing, suturing, etc., will directly affect the accuracy of the virtual simulation. , especially in the application of virtual surgery, it will affect the quality of virtual surgery. However, the existing model construction technology usually only involves the construction of a three-dimensional model of the internal organization. When interacting with the above three-dimensional model, the three-dimensional model cannot respond based on the interactive operation, thus greatly reducing the authenticity of the virtual simulation.

SUMMARY OF THE INVENTION

In view of this, the embodiments of the present invention provide a method and terminal device for constructing an internal tissue model, so as to solve the existing model construction technology, which often only involves the construction of a three-dimensional model of the internal tissue. , the three-dimensional model cannot respond based on interactive operations, and the authenticity of virtual simulation is low.

A first aspect of the embodiments of the present invention provides a method for constructing an internal organization model, including:

Obtain scan data about the internal tissue of the target object, and generate a three-dimensional model of the internal tissue based on the scan data; the three-dimensional model includes a plurality of different types of tissue in the internal tissue corresponding to one-to-one 3D tissue model;

respectively constructing tissue mechanics models for each of the three-dimensional tissue models;

Based on the three-dimensional model, multiple groups of model groups with adjacent relationships are determined, and contact force functions corresponding to each of the model groups are established; the model groups include at least two different types of the three-dimensional tissue models;

An internal tissue model corresponding to the internal tissue is generated according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force functions corresponding to all the model groups.

A second aspect of the embodiments of the present invention provides a terminal device, including:

A three-dimensional model building unit for acquiring scan data about the internal tissue of the target object, and generating a three-dimensional model of the internal tissue based on the scan data; the three-dimensional model includes a variety of different types of internal tissue Organize multiple 3D tissue models that correspond one-to-one;

a tissue mechanics model construction unit, used for constructing tissue mechanics models for each of the three-dimensional tissue models;

A contact force function establishment unit is used to determine a plurality of groups of model groups with adjacent relationships based on the three-dimensional model, and establish a contact force function corresponding to each of the model groups; the model group includes at least two different types of the three-dimensional tissue model;

An internal tissue model generating unit, configured to generate the corresponding internal tissue according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force functions corresponding to all the model groups. internal organizational model.

A third aspect of the embodiments of the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, when the processor executes the computer program Implement the steps of the first aspect.

A fourth aspect of the embodiments of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, each step of the first aspect is implemented.

Implementing a method for constructing an internal organization model and a terminal device provided by the embodiments of the present invention have the following beneficial effects:

When constructing an internal tissue model in this embodiment of the present invention, a three-dimensional model corresponding to the internal tissue is established by scanning data of the internal tissue. Since an internal tissue may contain a variety of different types of tissue, for example, the cardiac tissue contains vein tissue, Arterial tissue, blood tissue and muscle tissue, etc., different types of tissues have different feedbacks when they are subjected to force. In order to improve the accuracy of the internal tissue model, after the 3D model is constructed, the different types of 3D tissue models in the 3D model Construct corresponding tissue mechanics models, and divide them into multiple model groups according to whether there is an adjacent relationship between different three-dimensional tissue models, and establish corresponding contact force functions for different model groups, which can consider the force between different types of tissues. The effect of transmission, based on the 3D model, the tissue mechanics model and the contact force function, generates the internal tissue model, which can not only simulate the restoration of the internal tissue in the three-dimensional shape, but also enable the constructed virtual model to respond to the interactive operation, improving the performance. The degree of simulation of the model.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present invention. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

Fig. 1 is the realization flow chart of the construction method of a kind of internal organization model provided by the first embodiment of the present invention;

2 is a schematic diagram of an internal organization model provided by an embodiment of the present invention;

FIG. 3 is a specific implementation flowchart of a method S102 for constructing an internal organization model provided by the second embodiment of the present invention;

FIG. 4 is a specific implementation flowchart of a method S103 for constructing an internal organization model provided by the third embodiment of the present invention;

FIG. 5 is a specific implementation flowchart of a method S103 for constructing an internal organization model provided by the fourth embodiment of the present invention;

FIG. 6 is a flowchart of a specific implementation of a method for constructing an internal organization model provided by a fifth embodiment of the present invention;

7 is a structural block diagram of an apparatus for constructing an internal organization model provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram of a terminal device according to an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

When constructing an internal tissue model in this embodiment of the present invention, a three-dimensional model corresponding to the internal tissue is established by scanning data of the internal tissue. Since an internal tissue may contain a variety of different types of tissue, for example, the cardiac tissue contains vein tissue, Arterial tissue, blood tissue and muscle tissue, etc., different types of tissues have different feedbacks when they are subjected to force. In order to improve the accuracy of the internal tissue model, after the 3D model is constructed, the different types of 3D tissue models in the 3D model Construct corresponding tissue mechanics models, and divide them into multiple model groups according to whether there is an adjacent relationship between different three-dimensional tissue models, and establish corresponding contact force functions for different model groups, which can consider the force between different types of tissues. The effect of transmission, based on the three-dimensional model, tissue mechanics model and contact force function, generates an internal tissue model, which solves the existing model construction technology, which often only involves the construction of a three-dimensional model of the internal tissue. When interacting with the above three-dimensional models, The 3D model cannot respond based on interactive operations, and the authenticity of virtual simulation is low.

In the embodiment of the present invention, the execution body of the process is a terminal device, and the terminal device includes but is not limited to: a server, a computer, a smart phone, a tablet computer, and other devices that can perform the rendering task of a web page. In particular, the terminal device includes Display module, through which the rendered internal organization model can be output. Fig. 1 shows the realization flow chart of the construction method of the internal organization model provided by the first embodiment of the present invention, and details are as follows:

In S101, scan data about the internal tissue of the target object is acquired, and based on the scan data, a three-dimensional model of the internal tissue is generated; the three-dimensional model includes a plurality of different types of tissue in the internal tissue one by one Corresponding multiple three-dimensional tissue models.

In this embodiment, before a virtual model of a certain internal organization of the target object needs to be constructed, scan data corresponding to the internal organization can be acquired. The scan data is specifically computer tomography (Computer Tomography, CT) data, which can reflect the data of the internal structure of the internal tissue. The scan data may specifically be one frame of CT image, or may be multiple frames of CT images acquired at a preset acquisition interval in a continuous time. Of course, if the scan data uses other acquisition methods to determine the internal structure of the internal tissue, the above scan data will also not be used. Not limited to CT images, data in other formats may be used.

It should be noted that the above-mentioned target objects can be physical objects such as human bodies and animals; correspondingly, according to different target objects, the internal organization can also select any one or more of the organizations included in the target object as the internal parts of the virtual model that need to be constructed. organize. For example, if the target object is a human body, the internal tissue may specifically be heart tissue, liver tissue, pancreatic tissue, etc. Correspondingly, the constructed internal tissue models are specifically a heart model, a liver model, a pancreas model, and the like.

In a possible implementation manner, the terminal device is configured with an external scanning device, and when a virtual model of the internal organization of the target object needs to be constructed, the external scanning device can scan the area where the internal organization of the target object is located, thereby Obtain the above-mentioned scan data, and transmit the scan data to the terminal device through the established communication connection between the scan device and the terminal device.

In a possible implementation manner, the user may store the scan data of the internal organization of the virtual model (that is, the internal organization model) to be constructed in an external storage or a cloud server. In this case, the terminal device can communicate with the external storage. And the cloud server establishes a communication connection, and retrieves the scan data corresponding to the internal organization to be constructed from the external storage and the cloud server. Wherein, different internal organizations of different objects are associated with a data number, and the terminal device can find the corresponding scan data from the external storage or the cloud server through the above-mentioned data number, and retrieve it into the local storage. Of course, if a communication connection is established between the terminal device and the scanning device, the scanning device can directly send the scanning data to the terminal device through the established communication link.

In this embodiment, an internal tissue contains different types of tissues, and liver tissue is used as an example for illustration. The liver tissue may include tissue based on liver cells, vascular tissue, and blood tissue. If the internal tissue is a diseased tissue , may also include stone tissue, tumor tissue, etc. The terminal device can determine the various types of tissue contained in the internal tissue through scanning data, and build corresponding three-dimensional tissue models for different tissues, and then according to each three-dimensional tissue model The mutual positional relationship between them is combined to generate a three-dimensional tissue model corresponding to the above-mentioned internal tissue.

In a possible implementation manner, the terminal device may determine the size and contour feature data of different types of tissues in the internal tissue according to the above scan data, and then the terminal device imports the above size and contour feature data into a preset three-dimensional model to generate The algorithm can output the three-dimensional tissue model corresponding to the type of tissue, and determine the mutual positional relationship between different types of tissue from the scan data, so as to combine the three-dimensional tissue models to generate the three-dimensional model corresponding to the internal tissue.

In a possible implementation manner, before S101, the above-mentioned method for constructing an internal organization model may further include: the terminal device receives a model construction instruction initiated by a user; the model construction instruction contains the model type to be constructed; If the model type is an interactive model type, the operations of S101 to S104 are performed; if the model type is a non-interactive model type, scan data about the internal organization of the target object are acquired, and an internal organization model is generated based on the scan data , without obtaining the relevant mechanical model.

In S102, tissue mechanics models are respectively constructed for each of the three-dimensional tissue models.

In this embodiment, since different types of tissues contain different cells, water content, etc., there will be differences in response to force. For example, muscle tissue is elastic and deformable, and when subjected to external force The shape will change, and after the force is completed, it can return to its original state; while for bone tissue, it is not elastic, so it is difficult to deform when it is stressed. The original state, and prone to breakage and other situations. Based on this, in order to improve the accuracy of the entire internal tissue model in responding to interactive operations, that is, to better fit the actual situation of visceral tissue and improve the accuracy of simulation, the terminal device can be used for different types of internal organs according to the characteristics of the tissue type. The tissue constructs the corresponding tissue mechanics model.

In a possible implementation manner, the terminal device may store mechanical parameters of different tissue types, obtain the mechanical parameters associated with the tissue type from the database according to the tissue types contained in the internal tissue, and import the above-mentioned mechanical parameters into the preset to generate a tissue mechanical model corresponding to the tissue type.

Exemplarily, if the internal tissue is liver tissue, and the liver tissue may include tissue composed of liver cells, vascular tissue, blood tissue, and tumor tissue, the terminal device may establish a first mechanical model for the tissue composed of liver cells, which is A second mechanical model is established for vascular tissue, a third mechanical model is established for blood tissue, and a fourth mechanical model is established for tumor tissue.

In a possible implementation manner, different tissue types may be associated with different tissue mechanics templates, and the terminal device may obtain the associated tissue mechanics templates according to the tissue types, and import the mechanical parameters associated with the tissue types into the above tissue mechanics templates Inside, the corresponding tissue mechanics model is generated. For example, for blood tissue type, which belongs to non-Newtonian fluid, this type of tissue can correspond to a tissue mechanics template, and for tumor tissue type, which belongs to elastic tissue type, this type of tissue can correspond to another tissue mechanics template, for bone tissue If the tissue type belongs to the inelastic tissue type, this type of tissue can correspond to another tissue mechanics template. Therefore, when the terminal device generates the tissue mechanics model corresponding to the three-dimensional tissue model, it can obtain the tissue mechanics template corresponding to the three-dimensional tissue model. , and import the associated mechanical parameters into the tissue mechanics template to generate the tissue mechanics model.

In S103, based on the three-dimensional model, multiple groups of model groups with adjacent relationships are determined, and contact force functions corresponding to each of the model groups are established; the model groups include at least two different types of the three-dimensional tissues Model.

In this embodiment, the terminal device can divide the three-dimensional tissue models with adjacent relationships into the same model group according to the mutual positional relationship of each three-dimensional tissue model in the three-dimensional model, so that all three-dimensional tissue models included in all three-dimensional models can be divided into three-dimensional models. The organization model is divided into multiple model groups, that is, a model group contains two or more three-dimensional organization models with adjacent relationships. It should be noted that, since any three-dimensional tissue model may have an adjacent relationship with multiple other different three-dimensional tissue models, in this case, one three-dimensional tissue model may be in different model groups. It contains the following three types of tissue, namely liver cell tissue, blood vessel tissue and blood tissue, among which, blood vessel tissue is adjacent to blood tissue, so the above two types of three-dimensional tissue models can be divided into the first model group, while The vascular tissue is adjacent to the liver cell tissue, the above two types of 3D tissue models can be divided into the second model group. It can be seen that the first model group and the second model group both contain 3D tissue corresponding to the vascular tissue. A model, that is, a three-dimensional tissue model can appear in multiple model groups at the same time, which is determined according to its corresponding adjacent relationship.

In some existing internal tissue model construction techniques, when constructing the internal tissue model, taking the liver tissue model as an example, three three-dimensional tissue models of liver tissue parenchyma, blood vessels and capsule are established, and then these three parts are combined. The deformation characteristics of the target object constitute the composite deformation model of the liver of the target object. For the mechanical properties of the liver tissue parenchyma, the co-rotation finite element modeling method is used to analyze and model, but the viscoelastic characteristics of the organ tissue are ignored. Similarly, blood vessels and The co-rotational finite element modeling method is also used to establish the mechanical model of the liver capsule. It can be seen that the effect of different types of inter-tissue coupling forces is not considered in the existing construction technology.

Among other existing internal tissue model construction techniques, in terms of liver soft tissue deformation modeling, a method for constructing a liver mesh and meshless hybrid model is proposed for the large amount of simulation calculation and it is difficult to meet the real-time requirements. The meshless method is used in the surgical area, and the mesh method in the non-surgical area has higher computational efficiency and better deformation effect. However, this method only adopts a unified mechanical model for the whole liver, and does not clarify the anisotropy of different tissues in the liver. However, the mechanical models of different tissue types are often different and can be generalized. The finite element analysis and modeling method of liver soft tissue was carried out, and a hyper-viscoelastic model of liver tissue was established by combining the characteristics of hyperelasticity and viscoelasticity to simulate the stress characteristics of the liver. A combined mass-spring method for nonlinear viscoelastic properties of liver soft tissue and a soft tissue deformation modeling method based on position dynamics. The above methods all ignore the complex biomechanical properties of different liver tissues to a certain extent, thus reducing the simulation degree of the model.

In this embodiment, since the tissue mechanics model established above only considers its own performance under force, and in an internal tissue, there is also a force effect between different types of tissue, so it is necessary to consider the relationship between different tissues. The coupling force can further improve the simulation degree of the model.

In a possible implementation manner, the terminal device may store a contact force database, and the contact force database may store contact force functions between different types of tissues, and the terminal device may store the contact force function between different types of tissues according to the type, find the corresponding contact force function from the above-mentioned contact force database, and use it as the contact force function corresponding to the model group.

In a possible implementation manner, the terminal device can also acquire mechanical parameters corresponding to each type of tissue of the target object, and determine the contact force function between different types of tissue based on the above mechanical parameters, and use it as the model group The corresponding contact force function.

In S104, an internal tissue model corresponding to the internal tissue is generated according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force functions corresponding to all the model groups .

In this embodiment, after determining the three-dimensional model corresponding to the internal tissue, the tissue mechanics model corresponding to each three-dimensional tissue model in the three-dimensional model, and the contact force function corresponding to the model group, the terminal device can fuse and merge the above three types of data , thus forming an internal tissue model that can change the state of the model based on the interactive operation. When responding to the interactive operation, the terminal device can determine the magnitude of the deformation according to the contact force function of the model group where the area related to the interactive operation is located and the associated tissue mechanics model. as well as the response rate, which dynamically adjusts the shape of the internal tissue model.

In a possible implementation manner, the above-mentioned internal tissue model can not only change the shape of the internal tissue model according to the interactive operation, but also automatically change the shape of the internal tissue model according to the internal force. During the process, the food enters the stomach tissue, and the stomach tissue will perform corresponding movements during the digestion process. Therefore, the above-mentioned stomach tissue model can also be based on the preset tissue mechanics model and the contact force function between different types of tissues. To change the shape of the stomach tissue model to simulate the changes of the stomach tissue during the digestion process, of course, for the heart tissue model, the above method can also simulate the changes of the heart beating.

Exemplarily, FIG. 2 shows a schematic diagram of an internal organization model provided by an embodiment of the present application. Referring to (a) to (c) in FIG. 2 , the internal tissue model is specifically a liver tissue model. As shown in (a) to (c) of FIG. 2 , it specifically shows that the liver tissue model is in As for the changes when subjected to external force, the extent of change in the appearance of the above-mentioned liver tissue model and the speed of change are determined according to the tissue mechanics model and the contact force function.

In a possible implementation manner, after S104, the terminal device may construct a running script related to the internal organization, the running script includes at least one preset event, and the internal organization model may be based on the corresponding preset in the running script events to dynamically adjust the shape of the internal tissue model, which is determined according to a preset tissue mechanics model and a contact force function. As mentioned above, the above-mentioned preset events can be corresponding events according to different configurations of internal tissues, such as heart tissue, it can be a heart beating event, and if it is stomach tissue, it can be a digestion event; of course, if it is necessary to observe the internal tissue in The state when an abnormal event is encountered, the above-mentioned preset event can also be a corresponding abnormal event. For example, for cardiac tissue, the above-mentioned abnormal event can be an atrial fibrillation event, that is, a heart tissue model is used to simulate the user encountering an atrial fibrillation event. changes in the beating of the heart.

It can be seen from the above that when constructing an internal organization model in the method for constructing an internal organization model provided by the embodiments of the present invention, a three-dimensional model corresponding to the internal organization is established by scanning data of the internal organization. Since an internal organization may contain multiple Different types of tissues, for example, heart tissue includes vein tissue, arterial tissue, blood tissue and muscle tissue, etc. Different types of tissues have different feedbacks when they are stressed. In order to improve the accuracy of the internal tissue model, the three-dimensional After the model, corresponding tissue mechanics models will be constructed based on different types of three-dimensional tissue models in the three-dimensional model, and according to whether there is an adjacent relationship between different three-dimensional tissue models, they will be divided into multiple model groups, and established for different model groups. The corresponding contact force function can consider the effect of force transmission between different types of tissues. Based on the three-dimensional model, the tissue mechanics model and the contact force function, the internal tissue model can be generated, which can not only simulate and restore the internal tissue in three-dimensional form, but also The constructed virtual model can respond to the interactive operation, and the simulation degree of the model is improved.

FIG. 3 shows a specific implementation flowchart of a method S102 for constructing an internal organization model provided by the second embodiment of the present invention. Referring to FIG. 3 , with respect to the embodiment described in FIG. 1 , in the method for constructing an internal organization model provided in this embodiment, S102 includes: S1021 to S1023, which are described in detail as follows:

Further, the tissue mechanics model is constructed for each of the three-dimensional tissue models, including:

In S1021, if the type of the three-dimensional tissue model is a non-blood type, a first tissue mechanics model of the non-blood type three-dimensional tissue model is constructed based on a preset finite element equation; the first mechanical model is specifically: :

MU″+DU′+K(U)U=R

Among them, U is the nodal displacement vector; U' is the first derivative of the nodal displacement vector; U" is the second derivative of the nodal displacement vector; M is the mass matrix; D is the damping matrix; K is the stiffness matrix related to the nonlinearity of the deformation ; R is the nodal force vector.

In this embodiment, the terminal device can configure corresponding mechanical templates for different types of three-dimensional tissue models, so as to construct corresponding tissue mechanical models. Specifically, according to whether it is a blood type, the three-dimensional tissue model can be divided into two different types, that is, a three-dimensional tissue model of a blood tissue type and a three-dimensional tissue model of a non-blood tissue type. If the three-dimensional tissue model is a blood tissue type, the three-dimensional tissue model is specifically a non-Newtonian fluid, a non-solid shape, and the mechanical relationship of the model cannot be determined by the finite element segmentation method, so a type of mechanical template needs to be used. to construct a tissue mechanical model; if the three-dimensional tissue model is of non-blood type, the three-dimensional tissue model is a solid shape, and the mechanical relationship of the model can be determined by the finite element segmentation method, so another type of mechanical The template is used to construct a tissue mechanics model. Based on this, the terminal device will firstly determine whether the three-dimensional tissue model is of blood type. If not, the operation of S1021 is performed; if so, the operation of S1022 is performed.

In this embodiment, if the terminal device detects that any three-dimensional tissue model is of a non-blood type, a tissue mechanics model corresponding to the three-dimensional tissue model can be constructed through finite element equations, wherein the terminal device can obtain relevant physical parameters, such as The quality parameters, elastic parameters, damping parameters and rigidity parameters corresponding to the three-dimensional tissue model can be determined through the above parameters. The first derivative of the vector is related to the first derivative of the displacement vector, where the first derivative of the displacement vector is velocity), and the acceleration of the deformation response (related to the second derivative of the above-mentioned displacement vector). Of course, the terminal device can also obtain the damping parameters corresponding to the internal organization, Construct the above-mentioned damping matrix, and according to the rigidity parameters of the internal organization, construct the rigidity matrix of the above-mentioned internal organization, etc., based on the physical parameters of the internal organization, construct the corresponding matrix, and import the matrix into the above-mentioned finite element equation. The obtained finite element equation is used as the first tissue mechanics model corresponding to the three-dimensional tissue model.

In a possible implementation manner, the terminal device may acquire elastic image data corresponding to the internal tissue through the principle of elastic imaging, and acquire physical parameters corresponding to the internal tissue based on the elastic image data, where the physical parameters include the above-mentioned various parameters, and can also include elastic modulus and Poisson's ratio.

In S1022, if the type of the three-dimensional tissue model is a blood type, a second tissue mechanics model of the three-dimensional tissue model of the blood type is constructed based on a preset fluid mechanics constitutive equation; the second mechanical model is specifically: :

Among them, u is the velocity of the blood in the axial direction; r is the displacement vector of the blood in the axial direction; τ _c is the pressure, and k is the viscosity coefficient of the non-Newtonian fluid.

In this embodiment, if the terminal device detects that any three-dimensional tissue model is of blood type, a tissue mechanics model corresponding to the three-dimensional tissue model, that is, a second tissue mechanics model, can be constructed by using the fluid mechanics constitutive equation. The terminal device can obtain the viscosity of the blood to determine the viscosity coefficient of the above-mentioned non-Newtonian fluid, and obtain the blood pressure index to determine the flow velocity of the blood in the blood vessel, that is, the above-mentioned axial velocity, and determine the displacement vector, The above-mentioned pressure can also be determined by the blood pressure and the viscosity coefficient, so as to construct a second tissue mechanics model that obtains a three-dimensional tissue model related to the blood type.

In a possible implementation manner, the terminal device may store a parameter library, and the parameter library may record mechanical parameter lists corresponding to different types of tissues, and the mechanical parameter list may include mechanical parameters of different object types. For example, the The mechanical parameter list can record the mechanical parameters corresponding to different ages, different genders, different weights, and different heights for the same type of tissue, and form a mechanical parameter list about the type of tissue. The above mechanical parameters can be obtained by collecting a large number of object samples, and the terminal device can obtain the object information of the target object, and based on the object information, query the mechanical parameters associated with it from the mechanical parameter list, and construct the corresponding tissue based on the mechanical parameters. mechanical model.

In a possible implementation manner, the terminal device can also construct corresponding mechanical parameter calculation functions for different types of tissues by means of big data learning. In this case, the terminal device can import the object information of the target object into the In the mechanical parameter calculation function, the mechanical parameters of this type of tissue related to the object information can be output. The object information may include information such as the age of the object, the weight of the object, the height of the object, and the gender of the object.

In the embodiment of the present application, according to different types of three-dimensional tissue models, different equations are used to construct corresponding tissue mechanics models, which can improve the accuracy of tissue mechanics model construction, thereby improving the simulation degree of subsequent visceral tissue models.

FIG. 4 shows a specific implementation flowchart of a method S103 for constructing an internal organization model provided by the third embodiment of the present invention. Referring to FIG. 4 , with respect to the embodiment shown in FIG. 1 , a method S103 for constructing an internal organization model provided in this embodiment includes S401 to S402 , which are described in detail as follows:

Further, based on the three-dimensional model, multiple groups of model groups with adjacent relationships are determined, and contact force functions corresponding to each of the model groups are established, including:

In S401, if the model group includes a blood tissue model and a blood vessel tissue model, obtain mechanical physical parameters corresponding to the blood vessel tissue model, and obtain a distance value between the blood vessel tissue model and the blood tissue model .

In this embodiment, if the terminal device detects that the three-dimensional tissue model included in a certain model group is a blood tissue model and a blood vessel tissue model, it can acquire the mechanical and physical parameters corresponding to the blood vessel tissue model, as well as the distance between the blood and the blood vessel. value, among which, because there may be substances such as blood vessel wall and blood vessel membrane between blood and blood vessels, that is, there may be a certain distance between blood and blood vessel tissue, and the magnitude of the contact force will also vary according to the distance. Therefore, The terminal device can determine the distance value between the blood tissue model and the blood vessel tissue model through the three-dimensional model of the internal tissue.

It should be noted that, if the above parameters have been obtained when constructing the tissue mechanics model, it is only necessary to directly extract the relevant parameters in S401, and there is no need to obtain them again; on the contrary, if the tissue mechanics model is constructed, the parameters have not been obtained. For the relevant parameters (ie, the above-mentioned mechanical physical parameters and viscosity coefficient), the above-mentioned parameters can be determined by the elastic image data obtained based on the principle of elastography and the three-dimensional model constructed in S101 .

In S402, a first contact force function between the blood tissue model and the blood vessel tissue model is constructed based on the mechanical physical parameters and the distance value;

in,

is the first contact force between the blood tissue model and the blood vessel tissue model; γ is a preset penalty factor; k is the mechanical physical parameter corresponding to the blood vessel tissue model; δ is the blood tissue model the distance value from the vascular tissue model; r is the displacement vector of the blood in the axial direction.

In this embodiment, since the blood vessel tissue model is obtained based on finite element segmentation, and the blood tissue model is constructed based on infinite elements, the interaction force between finite elements and infinite elements can be determined through a penalty function. The mechanical and physical parameters corresponding to the blood vessel tissue model and the distance value obtained above are imported into the penalty function, so that the calculation function of the contact force between the blood and the blood vessel can be constructed, that is, the above-mentioned first contact force function. . The above-mentioned e is specifically a natural constant.

In the embodiment of the present application, the contact force function between the solid tissue and the fluid tissue can be determined by the penalty function, which can describe the interaction force between the two more accurately and improve the description of the coupling force between different types of tissue. accuracy, which in turn improves the simulation level of subsequent model building.

FIG. 5 shows a specific implementation flowchart of a method S103 for constructing an internal organization model provided by the fourth embodiment of the present invention. Referring to FIG. 5 , with respect to the embodiment shown in FIG. 1 , a method S103 for constructing an internal organization model provided in this embodiment includes: S501 to S504 , which are described in detail as follows:

In S501, if the three-dimensional tissue models included in the model group are all non-blood tissue models, respectively acquire elastography data corresponding to the three-dimensional tissue models of different types.

In this embodiment, if the terminal device recognizes that each three-dimensional tissue model in the model group is a non-blood tissue model, that is, is a solid type of tissue, in this case, the elastography corresponding to each three-dimensional tissue model can be obtained. data. It should be noted that the above-mentioned elastic imaging data may be acquired in advance, that is, when acquiring the scanning data of the internal tissue, the elastic imaging data of the internal tissue may be acquired through the elastic program module, and when the internal tissue model of the target object needs to be constructed, Send scan data and elastography data to terminal devices. Of course, the above-mentioned scan data and elastography data may also be acquired non-simultaneously, and the acquisition timing of elastography data is not limited here.

In a possible implementation manner, elastography data of different types of three-dimensional tissue models may be acquired simultaneously, that is, corresponding to the same elastography image. In this case, the terminal device may divide the elastography image into a plurality of data blocks according to the corresponding display area of each three-dimensional tissue model in the elastography image, and use the data block obtained from the elastography image as the three-dimensional elastography image. Elastography data corresponding to the tissue model.

In S502, mechanical physical parameters corresponding to the three-dimensional tissue model are determined based on the elastography data.

In this embodiment, the terminal device can extract the mechanical and physical parameters corresponding to the three-dimensional tissue model by analyzing the above elastography data. The above-mentioned mechanical and physical parameters may include: elastic parameters, Poisson's ratio, and the like.

In S503, acquiring the scan data of the internal tissue in consecutive multiple frames, and determining the coupling action parameters between the three-dimensional tissue models of different types.

In this embodiment, in addition to determining the mechanical and physical parameters related to each three-dimensional tissue model itself, the terminal device also needs to determine the mutual coupling action parameters, and the mutual coupling action parameters can be determined through continuous scanning data. Based on this, when the terminal device acquires the scan data of the internal tissue, it can continuously acquire multiple frames of scan data about the internal tissue based on the preset acquisition interval. A four-dimensional tissue model about the internal organization is constructed, and the coupling action parameters between the above-mentioned different types of three-dimensional tissue models can be extracted based on the four-dimensional tissue model.

Further, as another embodiment of the present application, the above S503 may specifically include the following two steps, respectively:

S5031: Determine from the scan data the tissue section data corresponding to the different types of the three-dimensional tissue models in the model group.

S5032 , obtaining the coupling action parameter based on the tissue section data in the scanning data of consecutive multiple frames.

In this embodiment, since the above-mentioned scan data corresponds to the entire internal tissue, when it is necessary to determine the contact force function corresponding to the different types of three-dimensional tissue models corresponding to the model group, it is possible to extract only the model from the scan data. The tissue section data corresponding to the related three-dimensional tissue models in the group, the tissue section data are extracted in the same way for the multi-frame scan data, so that the tissue section data corresponding to the different three-dimensional tissue models in the model group can be determined according to the consecutive multiple frames of tissue section data. Coupling action parameters.

In S504, a second contact force function corresponding to the model group is constructed based on the mechanical physical parameters and the coupling action parameters.

In this embodiment, after determining the mechanical and physical parameters of different types of three-dimensional tissue models and the coupling interaction parameters between them, the terminal device can import a preset contact force template between solid tissues, so as to generate the above-mentioned second contact force function.

In the embodiment of the present application, by acquiring the mechanical and physical parameters related to the three-dimensional tissue model itself, and the coupling action parameters of the three-dimensional tissue model between different types, the second contact force function corresponding to the model group is constructed and obtained, which can consider the self-organization. The characteristics and the mutual adhesion force improve the accuracy of the description of the second contact force function, which in turn improves the simulation degree of the constructed model.

FIG. 6 shows a specific implementation flow chart of a method for constructing an internal organization model provided by a fifth embodiment of the present invention. Referring to FIG. 6 , with respect to the embodiment described in any one of FIGS. 1-5 , in a method for constructing an internal tissue model provided by this embodiment, in the three-dimensional model according to the three-dimensional model and each of the three-dimensional models in the three-dimensional model After the tissue mechanics model corresponding to the tissue model and the contact force function corresponding to all the model groups are generated, the internal tissue model corresponding to the internal tissue further includes: S601-S602, the details are as follows:

After the internal tissue model corresponding to the internal tissue is generated according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force function corresponding to all the model groups ,Also includes:

In S601, the operation flow information about the internal tissue is acquired, and the operation simulation script corresponding to the operation flow information is generated.

In this embodiment, after generating the internal tissue model corresponding to the internal tissue, the terminal device can perform the operation of surgical simulation, that is, simulate the changes of the internal tissue during the operation, so as to achieve the purpose of surgical simulation. Based on this, the user can pre-configure the corresponding surgical process information, which can determine the steps to be performed in the surgical process, the interaction position of each step, the size of the interaction force and the size of the basic surface between the internal tissues, etc. Wait.

In this embodiment, after obtaining the surgical procedure information created by the user, the terminal device can convert the procedure information into a corresponding surgical simulation script, so as to simulate the surgical procedure.

In S602, a surgery simulation environment is constructed based on the internal tissue model, and the surgery simulation script is run in the surgery simulation environment to generate a simulation result report.

In this embodiment, the terminal device can build a corresponding surgical simulation environment based on the built internal tissue model, and run the above-mentioned surgical simulation script in the surgical simulation environment, so that the surgical process can be simulated and the entire surgical process can be generated. The corresponding simulation results are reported so that the user can clearly determine the overall surgical effect.

In a possible implementation manner, the terminal device may construct a corresponding surgical simulation environment based on the internal tissue model, receive an interactive operation initiated by the user, and change the state of the internal tissue model in the surgical simulation environment based on the above interactive operation, so as to realize real-time The purpose of simulating surgery.

In the embodiment of the present application, the surgical simulation environment is constructed by using the constructed interactive internal tissue model, which can realize the surgical simulation and output the corresponding simulation result report, which can facilitate the user to perform the surgical simulation before surgery and improve the surgical simulation. degree of simulation.

It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its functions and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

FIG. 7 shows a structural block diagram of an apparatus for constructing an internal organization model provided by an embodiment of the present invention, and each unit included in the terminal device is used to execute each step in the embodiment corresponding to FIG. 1 . For details, please refer to the relevant descriptions in FIG. 1 and the embodiment corresponding to FIG. 1 . For convenience of explanation, only the parts related to this embodiment are shown.

Referring to Figure 7, the construction device of the internal tissue model includes:

A three-dimensional model building unit 71, configured to acquire scan data about the internal tissue of the target object, and generate a three-dimensional model of the internal tissue based on the scan data; the three-dimensional model includes a variety of different types of internal tissue One-to-one correspondence of multiple 3D tissue models;

a tissue mechanics model building unit 72, configured to build a tissue mechanics model for each of the three-dimensional tissue models;

The contact force function establishment unit 73 is configured to determine, based on the three-dimensional model, a plurality of model groups with adjacent relationships, and establish a contact force function corresponding to each of the model groups; the model group includes at least two different types the three-dimensional tissue model;

An internal tissue model generation unit 74, configured to generate the internal tissue according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force function corresponding to all the model groups Corresponding internal organization model.

Optionally, the tissue mechanics model building unit 72 includes:

a non-blood type mechanical model construction unit, configured to construct a first tissue mechanical model of the non-blood type of the three-dimensional tissue model based on a preset finite element equation if the type of the three-dimensional tissue model is non-blood type; the The first mechanical model is specifically:

MU″+DU′+K(U)U=R

Among them, U is the nodal displacement vector; U' is the first derivative of the nodal displacement vector; U" is the second derivative of the nodal displacement vector; M is the mass matrix; D is the damping matrix; K is the stiffness matrix related to the nonlinearity of the deformation ; R is the nodal force vector;

a blood type mechanics model building unit, configured to construct a second tissue mechanics model of the three-dimensional tissue model of the blood type based on a preset fluid mechanics constitutive equation if the type of the three-dimensional tissue model is a blood type; The second mechanical model is as follows:

Optionally, the contact force function establishment unit 73 includes:

The blood vessel parameter obtaining unit is configured to obtain the mechanical physical parameters corresponding to the blood vessel tissue model if the model group includes the blood tissue model and the blood vessel tissue model, and obtain the relationship between the blood vessel tissue model and the blood tissue model. The distance value between;

a first contact force function establishment unit, configured to construct a first contact force function between the blood tissue model and the blood vessel tissue model based on the mechanical physical parameter and the distance value;

in,

Optionally, the contact force function establishment unit 73 includes:

an elastography data acquisition unit, configured to separately acquire elastography data corresponding to each of the different types of the three-dimensional tissue models if the three-dimensional tissue models included in the model group are all non-blood tissue models;

a mechanical and physical parameter acquisition unit, configured to determine the mechanical and physical parameters corresponding to the three-dimensional tissue model based on the elastography data;

a coupling action parameter determination unit, configured to acquire the scanning data of the internal tissue in consecutive multiple frames, and determine coupling action parameters between the three-dimensional tissue models of different types;

A second contact force function construction unit, configured to construct a second contact force function corresponding to the model group based on the mechanical physical parameters and the coupling action parameters.

Optionally, the coupling action parameter determination unit includes:

A tissue section data acquisition unit, for determining from the scan data the tissue section data corresponding to the three-dimensional tissue models of different types in the model group;

A coupling action parameter extraction unit, configured to obtain the coupling action parameter based on the tissue section data in the scanning data of consecutive multiple frames.

Optionally, the device for constructing the internal tissue model, further comprising:

a surgical simulation script generation unit, configured to acquire surgical procedure information about the internal tissue, and generate a surgical simulation script corresponding to the surgical procedure information;

A surgery simulation execution unit, configured to construct a surgery simulation environment based on the internal tissue model, and run the surgery simulation script in the surgery simulation environment to generate a simulation result report.

Optionally, the internal tissue includes liver tissue and/or heart tissue.

Therefore, the terminal device provided in the embodiment of the present invention can also build a three-dimensional model corresponding to the internal organization by scanning data of the internal organization when constructing the internal organization model. Since an internal organization may contain multiple different types of organizations, such as Cardiac tissue includes vein tissue, arterial tissue, blood tissue, and muscle tissue. Different types of tissue have different feedbacks when subjected to force. In order to improve the accuracy of the internal tissue model, after the 3D model is constructed, the 3D model Different types of 3D tissue models in the 3D tissue model are constructed with corresponding tissue mechanics models, and according to whether there is an adjacent relationship between different 3D tissue models, they are divided into multiple model groups, and corresponding contact force functions are established for different model groups. Considering the effect of force transmission between different types of tissues, the internal tissue model is generated based on the three-dimensional model, tissue mechanics model and contact force function, which can not only simulate and restore the internal tissue in three-dimensional form, but also enable the constructed virtual model. Responding to interactive operations improves the simulacrum of the model.

FIG. 8 is a schematic diagram of a terminal device according to another embodiment of the present invention. As shown in FIG. 8 , the terminal device 8 of this embodiment includes: a processor 80 , a memory 81 , and a computer program 82 stored in the memory 81 and executable on the processor 80 , for example, the construction of an internal organization model program. When the processor 80 executes the computer program 82, the steps in each of the above embodiments of the method for constructing an internal organization model are implemented, for example, S101 to S104 shown in FIG. 1 . Alternatively, when the processor 80 executes the computer program 82, the functions of the units in the above device embodiments, such as the functions of the modules 71 to 74 shown in FIG. 7, are implemented.

Exemplarily, the computer program 82 may be divided into one or more units, and the one or more units are stored in the memory 81 and executed by the processor 80 to complete the present invention. The one or more units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 82 in the terminal device 8 . For example, the computer program 82 can be divided into a three-dimensional model building unit, a tissue mechanics model building unit, a contact force function building unit, and an internal tissue model generating unit, and the specific functions of each unit are as described above.

The terminal device may include, but is not limited to, the processor 80 and the memory 81 . Those skilled in the art can understand that FIG. 8 is only an example of the terminal device 8, and does not constitute a limitation on the terminal device 8, and may include more or less components than those shown in the figure, or combine some components, or different components For example, the terminal device may further include an input and output device, a network access device, a bus, and the like.

The so-called processor 80 may be a central processing unit (Central Processing Unit, CPU), or other general-purpose processors, digital signal processors (Digital Signal Processors, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), Off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 81 may be an internal storage unit of the terminal device 8 , such as a hard disk or a memory of the terminal device 8 . The memory 81 may also be an external storage device of the terminal device 8, such as a plug-in hard disk equipped on the terminal device 8, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, Flash Card, etc. Further, the memory 81 may also include both an internal storage unit of the terminal device 8 and an external storage device. The memory 81 is used to store the computer program and other programs and data required by the terminal device. The memory 81 can also be used to temporarily store data that has been output or will be output.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it is still possible to implement the foregoing implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the within the protection scope of the present invention.

Claims

A method for constructing an internal organization model, comprising:

Obtain scan data about the internal tissue of the target object, and generate a three-dimensional model of the internal tissue based on the scan data; the three-dimensional model includes a plurality of different types of tissue in the internal tissue corresponding to one-to-one 3D tissue model;

respectively constructing tissue mechanics models for each of the three-dimensional tissue models;

Based on the three-dimensional model, multiple groups of model groups with adjacent relationships are determined, and contact force functions corresponding to each of the model groups are established; the model groups include at least two different types of the three-dimensional tissue models;

An internal tissue model corresponding to the internal tissue is generated according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force functions corresponding to all the model groups.
The construction method according to claim 1, wherein the construction of a tissue mechanics model for each of the three-dimensional tissue models comprises:

If the type of the three-dimensional tissue model is a non-blood type, a first tissue mechanics model of the three-dimensional tissue model of a non-blood type is constructed based on a preset finite element equation; the first mechanical model is specifically:

MU″+DU′+K(U)U=R

Among them, U is the nodal displacement vector; U' is the first derivative of the nodal displacement vector; U" is the second derivative of the nodal displacement vector; M is the mass matrix; D is the damping matrix; K is the stiffness matrix related to the nonlinearity of the deformation ; R is the nodal force vector;

If the type of the three-dimensional tissue model is a blood type, a second tissue mechanics model of the three-dimensional tissue model of the blood type is constructed based on a preset fluid mechanics constitutive equation; the second mechanical model is specifically:

Among them, u is the velocity of the blood in the axial direction; r is the displacement vector of the blood in the axial direction; τ c is the pressure, and k is the viscosity coefficient of the non-Newtonian fluid.
The construction method according to claim 1, wherein, determining a plurality of groups of model groups with adjacent relationships based on the three-dimensional model, and establishing a contact force function corresponding to each of the model groups, comprising:

If the model group includes a blood tissue model and a blood vessel tissue model, obtain the mechanical physical parameters corresponding to the blood vessel tissue model, and obtain a distance value between the blood vessel tissue model and the blood tissue model;

constructing a first contact force function between the blood tissue model and the blood vessel tissue model based on the mechanical physical parameters and the distance value;

in,
is the first contact force between the blood tissue model and the blood vessel tissue model; γ is a preset penalty factor; k is the mechanical physical parameter corresponding to the blood vessel tissue model; δ is the blood tissue model the distance value from the vascular tissue model; r is the displacement vector of the blood in the axial direction.
The construction method according to claim 1, wherein, determining a plurality of groups of model groups with adjacent relationships based on the three-dimensional model, and establishing a contact force function corresponding to each of the model groups, comprising:

If the three-dimensional tissue models included in the model group are all non-blood tissue models, respectively acquiring elastography data corresponding to the three-dimensional tissue models of different types;

determining mechanical physical parameters corresponding to the three-dimensional tissue model based on the elastography data;

Acquiring the scanning data in consecutive multiple frames of the internal tissue, and determining the coupling action parameters between the three-dimensional tissue models of different types;

Based on the mechanical physical parameters and the coupling action parameters, a second contact force function corresponding to the model group is constructed.
The construction method according to claim 4, wherein acquiring the scan data of the internal tissue in consecutive multiple frames, and determining the coupling action parameters between the three-dimensional tissue models of different types, comprises:

Determine from the scan data the tissue section data corresponding to the different types of the three-dimensional tissue models in the model group;

The coupling action parameter is obtained based on the tissue section data in the scanning data of consecutive multiple frames.
The construction method according to any one of claims 1-5, wherein in the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and all the model groups The corresponding contact force function, after generating the internal tissue model corresponding to the internal tissue, further includes:

Obtaining surgical procedure information about the internal tissue, and generating a surgical simulation script corresponding to the surgical procedure information;

A surgery simulation environment is constructed based on the internal tissue model, and the surgery simulation script is run in the surgery simulation environment to generate a simulation result report.
The identification method according to any one of claims 1-3, wherein the internal tissue comprises: liver tissue and/or heart tissue.
A device for constructing an internal tissue model, comprising:

A three-dimensional model building unit for acquiring scan data about the internal tissue of the target object, and generating a three-dimensional model of the internal tissue based on the scan data; the three-dimensional model includes a variety of different types of internal tissue Organize multiple 3D tissue models that correspond one-to-one;

a tissue mechanics model construction unit, used for constructing tissue mechanics models for each of the three-dimensional tissue models;

A contact force function establishment unit is used to determine a plurality of groups of model groups with adjacent relationships based on the three-dimensional model, and establish a contact force function corresponding to each of the model groups; the model group includes at least two different types of the three-dimensional tissue model;

An internal tissue model generating unit, configured to generate the corresponding internal tissue according to the three-dimensional model, the tissue mechanics model corresponding to each of the three-dimensional tissue models in the three-dimensional model, and the contact force functions corresponding to all the model groups. internal organizational model.
A terminal device, characterized in that the terminal device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program as claimed in the right The steps of any one of claims 1 to 7 of the method.
A computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.