Microcatheter shape determination method, microcatheter shaping method, electronic equipment and medium

Abstract

The invention discloses a microcatheter shape determination method, a microcatheter shaping method, electronic equipment and a medium. The micro-catheter form determination method comprises the following steps: extracting a blood vessel center line of a tumor-carrying blood vessel; constructing a micro-catheter model in an initial form based on the central line of the blood vessel; calculating a directed distance field of the tumor-carrying blood vessel to obtain a boundary constraint of the micro-catheter model; and applying a load to the micro-catheter model under the boundary constraint to calculate the form of the micro-catheter. Through the scheme of the embodiment of the invention, the boundary information inside and outside the tumor-carrying blood vessel can be obtained by calculating the directed distance field of the tumor-carrying blood vessel, so that the boundary information serves as boundary constraint to be added to the calculation process of deformation of the micro-catheter model, collision detection of the micro-catheter and the tumor-carrying blood vessel is realized in the simulation process, and then a reliable micro-catheter form is formed; therefore, the shaping of the microcatheter is guided, and the smooth implementation of embolism and the surgical treatment effect are guaranteed.

Description

Technical Field

[0001] The present disclosure generally relates to the field of simulation technology. More specifically, the present disclosure relates to a microcatheter morphology determination method, a microcatheter shaping method, an electronic device, and a computer-readable storage medium. Background Art

[0002] Intracranial aneurysm is a common cerebrovascular disease in neurosurgery. It refers to the weak part of the intracranial artery wall. Under the action of blood flow and blood pressure, it bulges out abnormally. Because of its tumor-like shape, it is called an intracranial aneurysm. Although its overall prevalence is about 3% to 5%, once it ruptures and causes subarachnoid hemorrhage, the mortality rate can reach 40%.

[0003] Aneurysm embolization is currently the main treatment method, which uses a microcatheter to deliver intra-tumor flow-disturbing devices such as coils to the aneurysm cavity to occlude the aneurysm. The shaping of the microcatheter is the key to the successful endovascular treatment of intracranial aneurysms. The precise microcatheter shape can reduce the risk of catheter rebound during coil embolization and promote complete filling of the aneurysm sac, thereby ensuring the safety and effectiveness of endovascular treatment. In other words, a good microcatheter shaping shape contributes to the smooth implementation of embolization surgery and the effectiveness of surgical treatment.

[0004] However, current microcatheter shaping mostly relies on the doctor's clinical experience. If the clinician is inexperienced or encounters complex blood vessels and hemangioma morphologies, multiple shaping procedures are often required, which not only prolongs the operation time and increases the patient's pain, but also affects the final surgical treatment effect.

[0005] Although there is currently a method that uses image processing technology to assist doctors in completing microcatheter shaping, it can only complete static simulation of the microcatheter morphology based on the morphology of the tumor-bearing blood vessels and aneurysms, and fails to take into account the problems of collision and support force when the microcatheter moves in the blood vessel. The reliability of the shaping morphology still has certain problems.

[0006] In view of this, there is an urgent need to provide a microcatheter morphology determination scheme so as to form a reliable microcatheter morphology to guide microcatheter shaping and ensure the smooth implementation of embolization surgery and the effectiveness of surgical treatment. Summary of the invention

[0007] In order to at least solve one or more of the technical problems mentioned above, the present disclosure proposes a microcatheter morphology determination solution in multiple aspects.

[0008] In a first aspect, the present disclosure provides a method for determining a microcatheter morphology, including: extracting a vascular centerline of a tumor-bearing vessel; constructing a microcatheter model of an initial morphology based on the vascular centerline; calculating a signed distance field of the tumor-bearing vessel to obtain a boundary constraint of the microcatheter model; and applying a load to the microcatheter model under the boundary constraint to calculate the microcatheter morphology.

[0009] In some embodiments, applying a load to a microcatheter model under boundary constraints to calculate the microcatheter morphology includes: applying a first load pointing in a first direction to the distal end point of the microcatheter in the microcatheter model to fix the distal end point of the microcatheter to a first preset position; applying a second load pointing in a second direction to the microcatheter model to fix a node in the microcatheter model to a second preset position; applying a third load pointing in a third direction to the proximal end point of the microcatheter in the microcatheter model until the displacement of the node of the microcatheter model meets a preset condition; and calculating the microcatheter morphology formed by the microcatheter model under the boundary constraints, the first load, the second load and the third load.

[0010] In some embodiments, the first direction points to the center of the aneurysm, and the distance between the first preset position and the center of the aneurysm is less than or equal to the first error threshold; the second direction points to the microcatheter support point, the microcatheter support point is located on the opposite side of the blood vessel wall where the aneurysm is located, and the distance between the second preset position and the microcatheter support point is less than or equal to the second error threshold; the third direction is the direction in which the proximal end point of the microcatheter points to its adjacent node, and the preset conditions include: the maximum displacement of the node of the microcatheter model is less than or equal to the third error threshold.

[0011] In some embodiments, constructing the microcatheter model with an initial shape based on the blood vessel centerline includes: constructing the microcatheter model according to the elastic rod model; and initializing the positions of nodes in the microcatheter model according to the blood vessel centerline to obtain the microcatheter model with an initial shape.

[0012] In some embodiments, constructing the microcatheter model according to the elastic rod model includes: describing the microcatheter model as a frame curve, and the reference frame of the microcatheter model is a straight line.

[0013] In some embodiments, extracting the vascular centerline of the tumor-bearing vessel includes: segmenting the tumor-bearing vessel and the aneurysm based on the medical image; determining the proximal end and the distal end of the tumor-bearing vessel on the tumor-bearing vessel; and extracting the vascular centerline between the proximal end and the distal end of the tumor-bearing vessel.

[0014] In some embodiments, in the initial configuration of the microcatheter model, the distal end of the microcatheter coincides with the distal end of the tumor-bearing vessel, and the proximal end of the microcatheter coincides with the proximal end of the tumor-bearing vessel.

[0015] In some embodiments, the distance between the proximal end of the parent vessel and the aneurysm is greater than or equal to a preset distance.

[0016] In some embodiments, after the blood vessels and aneurysms are segmented based on medical images, the microcatheter morphology determination method also includes: identifying the aneurysm center and the aneurysm neck center in the segmentation results; and determining the microcatheter support point on the tumor-bearing blood vessel based on the line connecting the aneurysm center and the aneurysm neck center.

[0017] In some embodiments, determining the microcatheter support point on the tumor-bearing vessel includes: forming a ray with the aneurysm center as the endpoint and the direction pointing to the aneurysm neck center; and using the intersection of the ray and the tumor-bearing vessel on the vessel wall as the microcatheter support point.

[0018] In some embodiments, the step of calculating the microcatheter morphology includes: determining the actual frame curve currently corresponding to the microcatheter model; and using the reference frame as the deformation direction of the actual frame curve, minimizing the deformation energy as the goal, and solving the equilibrium shape of the elastic rod model to obtain the microcatheter morphology.

[0019] In some embodiments, the deformation energy includes bending energy, torsional energy and tensile energy, and the tensile energy is 0.

[0020] In a second aspect, the present disclosure provides a microcatheter shaping method comprising: executing a method such as any one of the first aspects to obtain a microcatheter morphology; determining a microcatheter model; determining a rebound coefficient according to the microcatheter model; and adjusting the microcatheter morphology based on the rebound coefficient to obtain a shaping needle morphology; wherein the shaping needle morphology is used to prepare a shaping needle, and the shaping needle is used to shape the microcatheter.

[0021] In a third aspect, the present disclosure provides an electronic device comprising: a processor; and a memory storing executable program instructions, which, when executed by the processor, enables the device to implement any method according to the first aspect.

[0022] In a fourth aspect, the present disclosure provides a computer-readable storage medium having computer-readable instructions stored thereon, which, when executed by one or more processors, implement the method of any one of the first aspects.

[0023] Through the microcatheter morphology determination method provided above, the disclosed embodiment constructs a microcatheter model of the initial morphology through the extracted vascular centerline to guide, thereby simulating the microcatheter placed inside the tumor-bearing vessel. By calculating the directed distance field of the tumor-bearing vessel, the distance from any point in the model space to the surface of the tumor-bearing vessel can be obtained, thereby distinguishing the boundary information inside and outside the tumor-bearing vessel. This boundary information is used as a boundary constraint and added to the calculation process of the microcatheter model deformation, so that collision detection between the microcatheter and the tumor-bearing vessel can be achieved during the simulation process, thereby ensuring that the calculated microcatheter morphology meets the requirements of collision and support force during actual use, and ensuring the smooth implementation of the embolization surgery and the surgical treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] By reading the detailed description below with reference to the accompanying drawings, the above and other objects, features and advantages of the exemplary embodiments of the present disclosure will become readily understood. In the accompanying drawings, several embodiments of the present disclosure are shown in an exemplary and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein:

[0025] Figure 1 An exemplary flow chart showing a method for determining microcatheter morphology according to some embodiments of the present disclosure is shown;

[0026] Figure 2 An exemplary flow chart showing a method for simulating the microcatheter morphology according to some embodiments of the present disclosure;

[0027] Figure 3 An exemplary flow chart showing a method for extracting a blood vessel centerline according to some embodiments of the present disclosure;

[0028] Figure 4 An exemplary flow chart showing a method for extracting a blood vessel centerline according to other embodiments of the present disclosure;

[0029] Figure 5 A schematic diagram showing a microcatheter morphology determination process according to some embodiments of the present disclosure;

[0030] Figure 6 An exemplary flow chart showing a microcatheter shaping method according to some embodiments of the present disclosure is shown;

[0031] Figure 7 An exemplary structural block diagram of an electronic device according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0032] The following will be combined with the drawings in the embodiments of the present disclosure to clearly and completely describe the technical solutions in the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present disclosure.

[0033] It should be understood that the terms "include" and "comprising" used in the specification and claims of the present disclosure indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or collections thereof.

[0034] It should also be understood that the terms used in this disclosure are only for the purpose of describing specific embodiments and are not intended to limit the disclosure. As used in this disclosure and claims, the singular forms of "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It should also be further understood that the term "and / or" used in this disclosure and claims refers to any combination of one or more of the associated listed items and all possible combinations, including these combinations.

[0035] As used in this specification and claims, the term "if" may be interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [described condition or event] is detected" may be interpreted as meaning "upon determination" or "in response to determining" or "upon detection of [described condition or event]" or "in response to detecting [described condition or event]," depending on the context.

[0036] The specific implementation of the present disclosure is described in detail below with reference to the accompanying drawings.

[0037] Exemplary application scenarios

[0038] Aneurysm embolization is the main method for treating intracranial aneurysms. It uses a microcatheter to deliver intratumoral flow-disturbing devices such as coils to the aneurysm cavity to occlude the aneurysm. Since the vascular morphology and aneurysm morphology vary between patients, in order to ensure the treatment effect, the microcatheter morphology needs to be customized and shaped to ensure that the intratumoral flow-disturbing device can be accurately and safely delivered to the designated location.

[0039] In particular, the shape of the end of the microcatheter that first enters the blood vessel directly determines whether the microcatheter can reach the designated position and is related to the success or failure of the operation. In the past, before performing interventional surgery, doctors would imagine the three-dimensional vascular morphology based on two-dimensional medical images, and then manually shape the microcatheter in vitro. The shaping result depends entirely on the doctor's clinical experience. If the clinician is inexperienced or encounters complex blood vessels and hemangioma morphology, multiple shaping is often required, which not only prolongs the operation time and increases the patient's pain, but also affects the final surgical treatment effect.

[0040] Although there are some solutions that can use image processing technology to assist doctors in completing microcatheter shaping, they can only complete static simulation of the microcatheter morphology based on the morphology of the tumor-bearing blood vessels and aneurysms, and fail to take into account the problems of collision and support force when the microcatheter moves in the blood vessel. The reliability of the shaping morphology still has certain problems.

[0041] Exemplary Application Scenarios

[0042] In view of this, the disclosed embodiment provides a microcatheter morphology determination scheme, which constructs a microcatheter model of the initial shape through the guidance of the extracted vascular centerline, and distinguishes the inside and outside of the tumor-bearing vessel by calculating the directed distance field of the tumor-bearing vessel, thereby providing the boundary information required for collision detection for the movement of the microcatheter model in the tumor-bearing vessel, thereby ensuring that the calculated microcatheter morphology meets the requirements of collision and support force in actual use, thereby ensuring the smooth implementation of the embolization surgery and the surgical treatment effect.

[0043] Figure 1 An exemplary flow chart of a microcatheter morphology determination method 100 according to some embodiments of the present disclosure is shown. Figure 1 As shown, in step S101, the vascular centerline of the tumor-bearing vessel is extracted. Under ideal conditions, in order to ensure that the microcatheter can move smoothly in the tumor-bearing vessel and does not collide with and penetrate the vascular wall of the tumor-bearing vessel, the vascular centerline is the ideal moving path of the microcatheter. Therefore, when simulating the microcatheter insertion, the position and initial shape of the microcatheter model can be initialized based on the vascular centerline.

[0044] Furthermore, due to the morphology of the end of the microcatheter that first enters the blood vessel, hereinafter referred to as the distal end of the microcatheter, it directly determines whether the microcatheter can reach the designated position, which is related to the success or failure of the operation. In order to save computing resources, the morphology of the distal end of the microcatheter and the microcatheter segment nearby can be focused on. Considering the above factors, when extracting the vascular centerline of the tumor-bearing vessel, it is not necessary to extract the complete vascular centerline, and it is sufficient to extract the vascular centerline close to the aneurysm.

[0045] In step S102, an initial microcatheter model is constructed based on the blood vessel centerline. In the disclosed embodiment, the position of the microcatheter model coincides with the blood vessel centerline to form the initial shape of the microcatheter model, which can also be understood as a simulated shape of the microcatheter placed inside the tumor-bearing vessel.

[0046] In some embodiments, the micro-catheter model may adopt an elastic rod model (DER, Discrete Elastic Rods). The DER model is an effective computational model for simulating the deformation of slender structures. The DER model discretizes the continuous elastic rod into a series of nodes and edges, thereby capturing the complex phenomena such as bending, torsion and stretching that occur during the deformation process. In the disclosed embodiment, the above nodes and edges form the center line of the micro-catheter model, which can be bent and torsion but cannot be stretched. Collision detection and force transmission are performed based on these nodes and edges.

[0047] Specifically, the execution process of step S102 is as follows: constructing a microcatheter model according to the elastic rod model, and then initializing the positions of the nodes in the microcatheter model according to the center line of the blood vessel to obtain the microcatheter model in an initial form. Further, when constructing the microcatheter model according to the elastic rod model, the microcatheter model can be described as a frame curve, and at the same time, the reference frame of the microcatheter model is set to a straight line.

[0048] It should be noted that the reference frame describes the natural state of the microcatheter model, that is, the relaxed state of the microcatheter model when no force is applied. At this time, the microcatheter model does not generate deformation energy, which can be compared to the natural state of a spring when it is not compressed or stretched, and its elastic potential energy is zero. In this embodiment, the natural state of the microcatheter model is a straight line. Once bending or twisting occurs, the microcatheter model will be subjected to force, thereby moving in the deformation direction of restoring the straight line.

[0049] Furthermore, the microcatheter model can be described as the following frame curve: Γ = {γ(s); t(s), m 1 (s),m 2 (s)}, where γ(s) is a curve with arc length s as parameter, and the orthogonal standard material frame {t(s),m 1 (s),m 2 (s)} describes the local rotation, torsion and bending behavior of each segment in the DER model, t(s) is the tangent vector, m 1 (s) is the principal normal vector, m 2 (s) is the binormal vector, t(s) = γ′(s).

[0050] In step S103, the signed distance field of the tumor-bearing vessel is calculated to obtain the boundary constraints of the microcatheter model. The signed distance field (SDF) is a data set that defines the shape of an object by recording the distance from each point in space to the nearest surface of the object. It identifies the distance parameter to the specified position. Unlike ordinary distance fields, SDF identifies the direction by positive and negative signs. In this embodiment, the distance of a point inside the tumor-bearing vessel can be defined as a positive value, the distance of a point outside the tumor-bearing vessel can be defined as a negative value, and the distance of a point on the vessel wall of the tumor-bearing vessel can be defined as 0.

[0051] Furthermore, the position information of the points on the wall of the tumor-bearing vessel defines the boundary constraint of the moving area of ​​the microcatheter model. Once the microcatheter model breaks through the boundary constraint, it means that the microcatheter model collides with the wall of the tumor-bearing vessel and penetrates the wall of the vessel. Therefore, in the process of simulating the microcatheter, the distance between the node on the microcatheter model and the vessel wall can be efficiently queried using the directed distance field of the tumor-bearing vessel, and collision detection can be performed in real time to avoid penetration.

[0052] In step S104, a load is applied to the microcatheter model under the boundary constraint to calculate the microcatheter morphology. In the disclosed embodiment, a load needs to be applied to the microcatheter model to control the microcatheter model to reach a specified position. Applying a load to the microcatheter model will change the real-time morphology of the microcatheter model, thereby causing the microcatheter model to be subjected to force and move in a deformation direction to restore to a straight line shape. In order to avoid penetration, the directed distance field calculated in step S103 needs to be taken into consideration when calculating the microcatheter morphology.

[0053] Furthermore, in some embodiments, the micro-catheter model adopts the DER model, and the process of calculating the micro-catheter morphology is the process of solving the DER model. The goal of solving the DER model is to minimize the deformation energy E total To obtain the equilibrium shape of the rod, the variational method or gradient descent method can be used to solve it in practical applications. Based on this, when calculating the microcatheter shape, the actual frame curve currently corresponding to the microcatheter model can be determined first, that is, the real-time shape of the microcatheter model can be determined, and then the reference frame is used as the deformation direction of the actual frame curve, with the goal of minimizing the deformation energy, to solve the equilibrium shape of the elastic rod model to obtain the microcatheter shape.

[0054] Specifically, the deformation energy E total Includes: Bending Energy E bend , torsional energy E twist and stretching energy E stretch In this embodiment, the microcatheter is not stretchable, so the stretching energy E stretch is 0. The calculation formula of deformation energy is as follows:

[0055] E total (Γ) = E bend (Γ)+E twist (Γ);

[0056]

[0057] Among them, κ=t′, κ represents the curvature vector, ω=(ω 1 -ω 2 ) T Represents the material curvature of the real-time frame, which is a two-dimensional vector. ω 1 =t′·m 1 ,ω 2 =t′·m 2 , which represents the curvature vector in both directions of the center line. represents the curvature of the frame when no deformation occurs. When the initial curve is a straight line, m=m′ 1 ·m 2 It indicates the degree of twisting of the material frame along the tangent direction t.

[0058] Furthermore, in practical applications, in order to facilitate numerical calculations by computers, the frame curve needs to be discretized into a series of nodes {x i} and the rod segments connecting these nodes i =x i+1 -x i , the material frame can be expressed as Among them, t i represents the tangent vector of each rod segment, and are two orthogonal directions perpendicular to the rod.

[0059] The discretized bending energy is as follows:

[0060]

[0061] Where i represents the discretized segment index, B i is the bending modulus related to the material stiffness, κ bi is the curvature normal vector of the node,

[0062] The discretized torsion energy is as follows:

[0063]

[0064] Among them, θ i It represents the relative torsion angle of the material frame around the rod axis, T i is the torsional modulus, m i =θi -θ i-1 .

[0065] Although the centerline of the blood vessel is the ideal moving path of the microcatheter, in the actual surgical treatment process, considering that the microcatheter is a flexible body with elastic energy, a reverse force will be generated during the filling process of consumables. The microcatheter in a suspended state will experience a kicking phenomenon, that is, the end of the microcatheter will fall out of the aneurysm, which will be very dangerous during the operation. Therefore, when calculating the microcatheter shape, the microcatheter support point needs to be set to avoid the kicking phenomenon.

[0066] When simulating and calculating the microcatheter morphology, loads in different directions can be applied to several nodes on the microcatheter model to fix the nodes on the microcatheter model to key positions, thereby assisting in completing the targeted customized morphology design of the microcatheter.

[0067] Combine the following Figure 2 The simulation calculation process of the microcatheter morphology is explained. Figure 2 FIG. 2 is an exemplary flow chart of a method 200 for simulating and calculating the micro-catheter morphology of some embodiments of the present disclosure. It can be understood that the method for simulating and calculating the micro-catheter morphology is a specific implementation of the aforementioned step S104, so the aforementioned method is combined with the micro-catheter morphology of the embodiment of the present disclosure. Figure 1 The features described can analogously apply here.

[0068] like Figure 2 As shown, in step S201, a first load pointing in a first direction is applied to the distal end point of the microcatheter in the microcatheter model. The first load is used to fix the distal end point of the microcatheter to a first preset position. In this embodiment, the first direction points to the center of the aneurysm, and the first preset position is a position where the distance from the center of the aneurysm is less than or equal to the first error threshold, including the center of the aneurysm and its surrounding positions.

[0069] In step S202, a second load pointing to a second direction is applied to the microcatheter model. The second load is used to fix a node in the microcatheter model to a second preset position. In this embodiment, the second direction points to the microcatheter support point, and the microcatheter support point is located on the opposite side of the vascular wall where the aneurysm is located. The second preset position is a position where the distance from the microcatheter support point is less than or equal to the second error threshold, including the microcatheter support point and its surrounding positions.

[0070] Specifically, when executing step S202, the node closest to the microcatheter support point on the microcatheter model can be found first, and then a pulling force is applied to the node, the pulling force points to the second direction, so as to pull the node to the second preset position, and finally fix the node at the second preset position.

[0071] In step S203, a third load pointing to a third direction is applied to the proximal end point of the microcatheter in the microcatheter model. Specifically, the third load is applied until the displacement of the node of the microcatheter model meets a preset condition. In this embodiment, the third direction is the direction in which the proximal end point of the microcatheter points to its adjacent node, and the preset condition includes: the maximum displacement of the node of the microcatheter model is less than or equal to a third error threshold.

[0072] That is to say, when executing step S203, a thrust may be applied to the proximal end point of the microcatheter in the microcatheter model to move the microcatheter model and approach the aneurysm. In this process, the purpose of applying the thrust is to allow the microcatheter model to fully fit the vascular wall, so as to ensure the overall support of the microcatheter during actual surgery. The method for judging whether the microcatheter model fully fits the vascular wall is to judge the displacement of all nodes on the microcatheter model. When the maximum displacement of all nodes is less than or equal to the third error threshold, it is considered that all nodes on the microcatheter model have achieved complete support under the limiting effect of the vascular wall, that is, the microcatheter model has fully fit the vascular wall.

[0073] It should be noted that after fixing the distal end point of the microcatheter and a node in the microcatheter model to the above-mentioned corresponding positions and ensuring that the microcatheter model fully fits the blood vessel wall, it is possible to generate a microcatheter shape that can enter the aneurysm and has good support, thereby ensuring the reliability of the obtained microcatheter shape.

[0074] In step S204, the microcatheter morphology of the microcatheter model under the boundary constraint, the first load, the second load, and the third load is calculated. In this step, the first load fixes the microcatheter distal end point of the microcatheter model at the first preset position, the second load fixes a node on the microcatheter model at the second preset position, and with the application of the third load, the real-time morphology of the microcatheter model is changed compared to the initial morphology, and the microcatheter model is subjected to force and moves in the deformation direction of restoring the straight line morphology.

[0075] In addition, when calculating the microcatheter morphology, the directed distance field of the tumor-bearing blood vessel provides a boundary constraint for the microcatheter model. It should be noted that in order to avoid penetration, the boundary constraint is effective throughout the entire process of the microcatheter model being deformed by force. That is to say, in step S102 of the above embodiment, the microcatheter model is in an initial form, and the initial form is a non-linear form, so the microcatheter model will be deformed due to force, and the boundary constraint has been used for collision detection. Similarly, in steps S201, S202, and S203 of this embodiment, the real-time form of the microcatheter model is different from the linear form in the reference frame, and the microcatheter model will also be deformed due to force, so steps S201 to S203 also need to use the directed distance field for collision detection.

[0076] It is understandable that step S204 is substantially parallel to step S201 to step S203, and the collision detection between the microcatheter model and the tumor-bearing blood vessel is detected in real time. Once the microcatheter model is deformed from its natural form, it will move toward the natural form due to the energy generated by the deformation, and the microcatheter form is calculated. In order to facilitate the technical personnel to understand how this embodiment realizes the support of the microcatheter, this embodiment divides the step of fixing the microcatheter model node to the key position and the step of calculating the microcatheter form and explains the specific execution methods respectively.

[0077] Similar to the previous embodiment, in this embodiment, the micro-catheter model can also be constructed based on the elastic rod model. The micro-catheter model can be described as a frame curve, and its reference frame is a straight line. Accordingly, step S204 can also calculate the micro-catheter morphology by solving the DER model. The goal of solving the DER model is to minimize the deformation energy E total To obtain the equilibrium shape of the rod, the variational method or the gradient descent method can be used to solve it in practical applications. The calculation formula of the deformation energy has been described in detail in the previous embodiment, and will not be elaborated here.

[0078] Furthermore, the key nodes required for the simulation calculation of the microcatheter morphology can be determined in the process of extracting the centerline of the blood vessel. Figure 3 The method of extracting the centerline of a blood vessel is described. Figure 3 FIG. 3 is an exemplary flow chart of a method 300 for extracting a blood vessel centerline according to some embodiments of the present disclosure. It can be understood that the method for extracting a blood vessel centerline is a specific implementation of the aforementioned step S101, so the aforementioned method is combined with the Figure 1 The features described can analogously apply here.

[0079] like Figure 3 As shown, in step S301, the parent vessel and aneurysm are segmented based on the medical image. As an example, the anatomical structure of the parent vessel is extracted from the preoperative three-dimensional digital subtraction angiography tomographic image. The grayscale of the vascular structure in the image is significantly higher than that of other tissue structures. Therefore, the parent vessel can be easily segmented from the medical image by using region growing and / or other morphological processing techniques. Then, the vascular surface is reconstructed by algorithms such as MarchingCube, and the vascular surface mesh is smoothed by a smoothing algorithm.

[0080] It should be noted that, in addition to the three-dimensional digital subtraction angiography tomographic images, the medical images may also be other types of medical images such as CT angiography images and / or magnetic resonance angiography images. In addition to the MarchingCube algorithm, other three-dimensional image processing algorithms may also be used to reconstruct the blood vessel surface, and other morphological methods may be used to process the blood vessel surface, and no excessive restrictions are imposed here.

[0081] As an example, the segmentation of aneurysms can be performed manually. The doctor manually selects the aneurysm neck plane on the tumor-bearing vessel model based on clinical experience to extract the aneurysm. As another example, the aneurysm can also be automatically extracted through image processing technology, such as feature extraction algorithms. After the aneurysm is extracted, the system automatically calculates the morphological parameters of the aneurysm, which include the aneurysm center and the aneurysm neck center. These two parameters will serve as a reference for microcatheter path simulation.

[0082] In step S302, the proximal end and the distal end of the parent vessel are determined on the parent vessel. In this embodiment, the proximal end of the parent vessel is located on the side of the parent vessel closer to the heart than the aneurysm, and the distal end of the parent vessel is located on the side of the parent vessel farther from the heart than the aneurysm.

[0083] In this embodiment, the proximal end and the distal end of the tumor-bearing vessel can be manually selected by the doctor or automatically selected by the system. Whether manually or automatically selected, it is necessary to ensure that the distance between the proximal end of the tumor-bearing vessel and the aneurysm is greater than or equal to the preset distance, for example: 15 cm, thereby ensuring that there is a sufficient length of the vascular centerline for subsequent microcatheter path simulation. It should be noted that the preset distance can also be adjusted to other values ​​besides 15 cm.

[0084] In step S303, the vascular centerline between the proximal end of the parent vessel and the distal end of the parent vessel is extracted. In practical applications, the vascular centerline from the proximal end of the parent vessel to the distal end of the parent vessel can be automatically extracted using the VMTK toolkit, and the vascular centerline can be used to indicate the route and direction of the microcatheter during the delivery process.

[0085] Specifically, when simulating the path of the microcatheter, the distal end of the microcatheter can be made to coincide with the distal end of the tumor-bearing vessel, and the proximal end of the microcatheter can be made to coincide with the proximal end of the tumor-bearing vessel. The centerline of the blood vessel from the proximal end of the tumor-bearing vessel to the distal end of the tumor-bearing vessel simulates the path of the microcatheter model entering the tumor-bearing vessel, thereby reflecting the initial shape of the microcatheter model after being placed in the tumor-bearing vessel. In other words, the centerline of the microcatheter model in the initial shape coincides with the centerline of the blood vessel.

[0086] Furthermore, in order to determine the position of the microcatheter support point, Figure 4 FIG. 4 is an exemplary flow chart of a method 400 for extracting a blood vessel centerline according to another embodiment of the present disclosure. It can be understood that the method for extracting a blood vessel centerline is a specific implementation of the aforementioned step S101. Figure 1 The features described can analogously apply here.

[0087] like Figure 4 As shown, in step S401, the parent vessel and the aneurysm are segmented based on the medical image. In this embodiment, the content of step S401 is consistent with step S301 in the above embodiment, and will not be repeated here.

[0088] In step S402, the proximal end and the distal end of the parent vessel are determined on the parent vessel. In this embodiment, the content of step S402 is consistent with step S302 in the above embodiment, and will not be repeated here.

[0089] In step S403, the aneurysm center and the aneurysm neck center are identified in the segmentation result. In this step, the aneurysm center refers to the center of the aneurysm body, and the connection between the aneurysm and the parent vessel is called the aneurysm neck, and the geometric center of this area is the aneurysm neck center. As an example, a pre-trained convolutional neural network based on deep learning can be used to effectively identify the aneurysm center and the aneurysm neck center from the segmented image.

[0090] In step S404, the centerline of the vessel between the proximal end of the parent vessel and the distal end of the parent vessel is extracted. In this embodiment, the content of step S404 is consistent with step S303 in the above embodiment, and will not be repeated here.

[0091] It should be noted that, in the actual execution process, it is only necessary to ensure that step S404 is executed after step S402. In other words, step S404 can also be executed before step S403.

[0092] In step S405, the microcatheter support point is determined on the parent vessel according to the line connecting the center of the aneurysm and the center of the aneurysm neck. Specifically, when executing step S405, a ray is first formed with the center of the aneurysm as the endpoint and the direction pointing to the center of the aneurysm neck, and then the intersection of the ray and the parent vessel on the vessel wall is found. The vessel wall here refers to the vessel wall on the opposite side of the vessel wall where the aneurysm is located. The intersection found is the microcatheter support point.

[0093] Based on the previous Figure 1 , Figure 2 , Figure 3 and / or Figure 4 The described method, some embodiments of the present disclosure provide a Figure 5 The method for determining the microcatheter morphology shown, Figure 5A schematic diagram illustrating a microcatheter morphology determination process according to some embodiments of the present disclosure.

[0094] like Figure 5 As shown, in stage a, the parent vessel and aneurysm need to be segmented from the medical image. Further, the mesh data of the triangular facets can be reconstructed based on the segmented data, and the mesh data can be smoothed to obtain the model of the aneurysm and the parent vessel.

[0095] In stage b, the aneurysm center and the aneurysm neck center (yellow dot in the figure) are identified based on the model obtained in stage a. The microcatheter support point can be calculated based on the aneurysm center and the aneurysm neck center. The microcatheter support point is located on the opposite side of the aneurysm vessel wall. A ray is constructed with its endpoint at the aneurysm center and its direction pointing to the aneurysm neck center. The intersection of the ray and the vessel wall is considered to be the microcatheter support point.

[0096] In stage c, the vascular centerline of the tumor-bearing vessel is calculated. The vascular centerline is used to initialize the position and shape of the microcatheter model, thereby forming a microcatheter model with an initial shape.

[0097] In stage d, a pulling force may be applied to the distal end of the microcatheter in the microcatheter model, with the pulling force directed toward the center of the aneurysm. When the distance between the distal end of the microcatheter and the center of the aneurysm is less than or equal to a first error threshold, the distal end of the microcatheter is fixed at this position.

[0098] In stage e, tension can be applied to the node on the microcatheter model that is closest to the microcatheter support point, with the tension direction pointing to the microcatheter support point. When the distance between the node and the microcatheter support point is less than or equal to the second error threshold, the node is fixed at this position.

[0099] In stage f, a thrust can be applied to the proximal end point of the microcatheter in the microcatheter model until the maximum displacement of all nodes on the microcatheter model is less than or equal to the third error threshold, indicating that the microcatheter model has fully fitted the vascular wall and the simulation has become stable. The variational method or gradient descent method can be used to solve the equilibrium shape of the elastic rod of the DER model, thereby calculating the microcatheter shape.

[0100] Based on the microcatheter morphology determination method provided in any of the above embodiments, the present disclosure further provides a microcatheter shaping method, which can use a hot steam shaping method to shape a surgical microcatheter. The hot steam shaping method is to first make a 1:1 shaping needle, then insert the shaping needle into one end of the surgical microcatheter, and after heating it on hot steam for a certain period of time, quickly cool the surgical microcatheter to shape it.

[0101] Considering that different micro-catheter models have different coefficients of resilience, some embodiments of the present disclosure provide Figure 6 The microcatheter shaping method shown, Figure 6An exemplary flow chart of a microcatheter shaping method 600 according to some embodiments of the present disclosure is shown.

[0102] like Figure 6 As shown, in step S601, the vascular centerline of the tumor-bearing vessel is extracted. In this step, the tumor-bearing vessel and the aneurysm can be segmented based on the medical image, and then the vascular centerline from the proximal end of the tumor-bearing vessel to the distal end of the tumor-bearing vessel is found through a neural network model and / or a morphological processing method. In the process of extracting the vascular centerline, the center of the aneurysm and the center of the neck of the aneurysm can also be identified to determine the microcatheter support point on the tumor-bearing vessel.

[0103] In step S602, a microcatheter model of an initial shape is constructed based on the centerline of the blood vessel. In this step, the microcatheter model can adopt the DER model, and the microcatheter model can be described as a frame curve, and its reference frame is a straight line. The centerline of the microcatheter model of the initial shape coincides with the centerline of the blood vessel, specifically, the distal end point of the microcatheter coincides with the distal end of the tumor-bearing vessel, and the proximal end point of the microcatheter coincides with the proximal end of the tumor-bearing vessel.

[0104] In step S603, the signed distance field of the tumor-bearing vessel is calculated to obtain the boundary constraints of the microcatheter model. The signed distance field of the tumor-bearing vessel provides the distance from each position in space to the surface of the tumor-bearing vessel. Based on the signed distance field, the system can detect in real time whether the microcatheter model penetrates the vessel wall of the tumor-bearing vessel, thereby performing collision detection in real time.

[0105] In step S604, a load is applied to the microcatheter model under the boundary constraint to calculate the microcatheter morphology. Considering the support requirements of the microcatheter during the actual operation, some embodiments of the present disclosure design the applied load, fix some nodes on the microcatheter model to preset positions, and apply thrust to make the microcatheter model fit on the blood vessel wall to provide sufficient support force, thereby generating a microcatheter shape that can enter the aneurysm and has good support, thereby ensuring the reliability of the obtained microcatheter morphology.

[0106] It should be noted that the specific calculation method has been described in detail in the previous embodiments and will not be repeated here.

[0107] In step S605, the microcatheter model is determined. After the microcatheter is steamed and the shaping needle is pulled out, there will be a certain amount of rebound. Different microcatheter models have different rebound coefficients. For example, the rebound coefficient of the Echelon-10 microcatheter is 2.0, and the rebound coefficient of the Headway microcatheter is 1.0. This results in different degrees of error between the shape of the final microcatheter and the ideal shape.

[0108] In step S606, the rebound coefficient is determined according to the microcatheter model. In order to solve the morphological error in a targeted manner and ensure the surgical effect, the shape of the shaping needle needs to be adjusted according to the rebound coefficient corresponding to different microcatheter models, so that the error between the shape formed by the rebound of each model of microcatheter after the shaping needle is pulled out and the ideal shape is small or even consistent.

[0109] It should be noted that step S605 and step S606 may also be performed before any step from step S601 to step S604.

[0110] In step S607, the micro-catheter shape is adjusted based on the rebound coefficient to obtain a shaping needle shape. The shaping needle shape is used to prepare a shaping needle with a ratio of 1:1, and the prepared shaping needle can be used to shape the micro-catheter by a hot steam shaping method.

[0111] In summary, the disclosed embodiment provides a method for determining the microcatheter morphology, which divides the inside and outside of the tumor-bearing vessel by calculating the signed distance field of the tumor-bearing vessel, thereby providing boundary constraints for the simulation calculation of the microcatheter morphology, thereby realizing collision detection and improving the reliability of the microcatheter morphology, thereby ensuring the accuracy of the shaped microcatheter and the surgical effect.

[0112] Some embodiments of the present disclosure also provide a simulation calculation method for the microcatheter morphology, which takes into account the support requirements of the microcatheter during actual surgery, and ensures the support of the microcatheter model in the tumor-bearing blood vessel by applying loads in different directions at different positions, thereby generating a microcatheter shape that can enter the aneurysm and has good support, thereby ensuring the reliability of the microcatheter morphology.

[0113] Some embodiments of the present disclosure also provide a microcatheter shaping method, which adjusts the shape of the shaping needle based on the rebound coefficient of different microcatheter models to compensate for the error between the actual shape and the ideal shape of the microcatheter caused by the rebound phenomenon, thereby ensuring the accuracy of the microcatheter used in surgery and ensuring the surgical effect.

[0114] In order to implement the method steps described in the foregoing text of this disclosure in conjunction with the accompanying drawings at the software and hardware level, the present disclosure also provides the following Figure 7 The electronic device shown. Specifically, Figure 7 An exemplary structural block diagram of an electronic device 700 according to an embodiment of the present disclosure is shown.

[0115] like Figure 7 As shown, the electronic device 700 disclosed herein may include a processor 710 and a memory 720. Specifically, executable program instructions are stored in the memory 720. When the program instructions are executed by the processor 710, the electronic device implements the above-mentioned Figure 1-Figure 6The method steps are described.

[0116] It is understood that in order to clearly illustrate the solution of the present disclosure and avoid confusion with the prior art, Figure 7 The electronic device 700 only shows the components related to the embodiment of the present disclosure, and omits those components that may be necessary for implementing the embodiment of the present disclosure but belong to the scope of the prior art. Therefore, based on the content disclosed in the present disclosure, a person skilled in the art can clearly understand that the electronic device 700 of the present disclosure may also include components related to the embodiment of the present disclosure. Figure 7 The constituent elements shown in are different from the common constituent elements.

[0117] In an exemplary implementation scenario, the above-mentioned processor 710 can control the overall operation of the electronic device 700. For example, the processor 710 can control the operation of the electronic device 700 by executing the program stored in the memory 720. In terms of implementation, the processor 710 of the present disclosure can be implemented by a central processing unit (CPU), an application processor (AP), an artificial intelligence processor chip (IPU), etc. provided in the electronic device 700. Further, the processor 710 of the present disclosure can also be implemented in any appropriate manner. For example, the processor 710 can take the form of a computer-readable medium, a logic gate, a switch, an application-specific integrated circuit (ASIC), a programmable logic controller, and an embedded microcontroller, etc., such as a microprocessor or a processor and a computer-readable program code (such as software or firmware) that can be executed by the (micro) processor.

[0118] In terms of storage content, the memory 720 can be used to store hardware of various data and instructions processed in the electronic device 700. For example, the memory 720 can store processed data and data to be processed in the electronic device 700. The memory 720 can store data sets that have been processed or to be processed by the processor 710. In addition, the memory 720 can store applications, drivers, etc. to be driven by the electronic device 700. For example: the memory 720 can store various programs related to model building and constraint setting to be executed by the processor 710. The memory 720 can be a DRAM, but the present disclosure is not limited to this. In terms of type, the memory 720 may include at least one of a volatile memory or a non-volatile memory. The non-volatile memory may include a read-only memory (ROM), a programmable ROM (PROM), an electrically programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a phase change RAM (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), etc. The volatile memory may include a dynamic RAM (DRAM), a static RAM (SRAM), a synchronous DRAM (SDRAM), a PRAM, an MRAM, an RRAM, a ferroelectric RAM (FeRAM), etc. In an embodiment, the memory 720 may include at least one of a hard disk drive (HDD), a solid state drive (SSD), a high-density flash memory (CF), a secure digital (SD) card, a micro secure digital (Micro-SD) card, a mini secure digital (Mini-SD) card, an extreme digital (xD) card, caches, or a memory stick.

[0119] In summary, the specific functions implemented by the memory 720 and the processor 710 of the electronic device 700 provided in the implementation mode of this specification can be explained in comparison with the aforementioned implementation modes in this specification, and can achieve the technical effects of the aforementioned implementation modes, and will not be repeated here.

[0120] Additionally or optionally, the present disclosure may also be implemented as a non-temporary machine-readable storage medium (or computer-readable storage medium, or machine-readable storage medium) on which computer program instructions (or computer program, or computer instruction code) are stored. When the computer program instructions (or computer program, or computer instruction code) are executed by a processor of an electronic device (or electronic device, server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present disclosure.

[0121] Although multiple embodiments of the present disclosure have been shown and described herein, it will be apparent to those skilled in the art that such embodiments are provided by way of example only. Those skilled in the art may think of many changes, modifications, and alternatives without departing from the thought and spirit of the present disclosure. It should be understood that in the process of practicing the present disclosure, various alternatives to the embodiments of the present disclosure described herein may be adopted. The attached claims are intended to define the scope of protection of the present disclosure, and therefore cover equivalents or alternatives within the scope of these claims.

[0122] The collection and acquisition of various data in this disclosure complies with relevant laws and regulations and is authorized by the data provider. Any organization or individual that needs to obtain external data must obtain authorization in accordance with the law and ensure data security. It is prohibited to illegally collect, use, process, or transmit unauthorized or unprotected data, or to illegally buy, sell, provide, or disclose unauthorized or unprotected data.

Claims

1. A method for determining microcatheter morphology, characterized in that: include: Extract the vascular centerline of the tumor-bearing vessel; constructing a microcatheter model of initial shape based on the centerline of the blood vessel; calculating the signed distance field of the tumor-bearing blood vessel to obtain the boundary constraints of the microcatheter model; and A load is applied to the microcatheter model under the boundary constraints to calculate the microcatheter shape.

2. The method for determining the microcatheter morphology according to claim 1, characterized in that: Wherein applying a load to the microcatheter model under the boundary constraint to calculate the microcatheter shape comprises: Applying a first load pointing in a first direction to the distal end point of the microcatheter in the microcatheter model to fix the distal end point of the microcatheter to a first preset position; Applying a second load directed in a second direction to the microcatheter model to fix a node in the microcatheter model to a second preset position; Applying a third load directed in a third direction to the proximal end point of the microcatheter in the microcatheter model until the displacement of the node of the microcatheter model meets a preset condition; and The microcatheter shape formed by the microcatheter model under the boundary constraint, the first load, the second load and the third load is calculated.

3. The method for determining the microcatheter morphology according to claim 2, characterized in that: wherein the first direction points to the center of the aneurysm, and the distance between the first preset position and the center of the aneurysm is less than or equal to a first error threshold; The second direction points to a microcatheter support point, the microcatheter support point is located on the opposite side of the blood vessel wall where the aneurysm is located, and the distance between the second preset position and the microcatheter support point is less than or equal to a second error threshold; The third direction is the direction in which the proximal end point of the microcatheter points to its adjacent node. The preset condition includes: the maximum displacement of the node of the microcatheter model is less than or equal to a third error threshold.

4. The method for determining the microcatheter morphology according to claim 1 or 2, characterized in that: The microcatheter model of the initial shape is constructed based on the center line of the blood vessel, including: Constructing the microcatheter model according to the elastic rod model; and The positions of the nodes in the microcatheter model are initialized according to the blood vessel centerline to obtain the microcatheter model in an initial shape.

5. The method for determining the microcatheter morphology according to claim 4, characterized in that: Wherein constructing the microcatheter model according to the elastic rod model comprises: The microcatheter model is described as a frame curve, and the reference frame of the microcatheter model is a straight line.

6. The method for determining the microcatheter morphology according to claim 3, characterized in that: The extraction of the vascular centerline of the tumor-bearing vessel includes: Segmentation of parent vessels and aneurysms based on medical images; and Determining a proximal end of the tumor-bearing vessel and a distal end of the tumor-bearing vessel on the tumor-bearing vessel; and The blood vessel centerline between the proximal end of the tumor-bearing blood vessel and the distal end of the tumor-bearing blood vessel is extracted.

7. The method for determining the microcatheter morphology according to claim 6, characterized in that: In the initial microcatheter model, the distal end of the microcatheter coincides with the distal end of the tumor-bearing vessel, and the proximal end of the microcatheter coincides with the proximal end of the tumor-bearing vessel.

8. The method for determining the microcatheter morphology according to claim 6, characterized in that: The distance between the proximal end of the tumor-bearing vessel and the aneurysm is greater than or equal to a preset distance.

9. The method for determining the microcatheter morphology according to claim 6, characterized in that: After the blood vessels and aneurysms are segmented based on the medical images, the microcatheter morphology determination method further includes: identifying the aneurysm center and the aneurysm neck center in the segmentation result; and The microcatheter support point is determined on the tumor-bearing blood vessel according to a line connecting the center of the aneurysm and the center of the aneurysm neck.

10. The method for determining the microcatheter morphology according to claim 9, characterized in that: Wherein determining the microcatheter support point on the tumor-bearing blood vessel comprises: forming a ray with the center of the aneurysm as an endpoint and directed toward the center of the aneurysm neck; and The intersection point between the ray and the tumor-bearing blood vessel on the blood vessel wall is used as the supporting point of the microcatheter.

11. The method for determining the microcatheter morphology according to claim 5, characterized in that: The step of calculating the microcatheter morphology comprises: Determining an actual frame curve currently corresponding to the microcatheter model; and The reference frame is used as the deformation direction of the actual frame curve, and the minimization of deformation energy is used as the goal to solve the equilibrium shape of the elastic rod model to obtain the microcatheter shape.

12. The method for determining the microcatheter morphology according to claim 11, characterized in that: The deformation energy includes bending energy, torsional energy and stretching energy, and the stretching energy is 0.

13. A microcatheter shaping method, characterized in that: include: Performing the method according to any one of claims 1 to 12 to obtain a microcatheter morphology; Determine the microcatheter model; Determining the coefficient of resilience according to the microcatheter model; as well as Adjusting the microcatheter shape based on the rebound coefficient to obtain a shaping needle shape; Among them, the shaping needle shape is used to prepare a shaping needle, and the shaping needle is used to shape a microcatheter.

14. An electronic device, characterized in that: include: processor; as well as A memory storing executable program instructions, which, when executed by the processor, enables the device to implement the method according to any one of claims 1 to 13.

15. A computer-readable storage medium, characterized in that: Computer-readable instructions are stored thereon, and when the computer-readable instructions are executed by one or more processors, the method according to any one of claims 1 to 13 is implemented.

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