CN119867935B

CN119867935B - Multimodal electromagnetic navigation-assisted transnasal endoscopic anatomical measurement device and method for fresh cadaver heads

Info

Publication number: CN119867935B
Application number: CN202510324238.8A
Authority: CN
Inventors: 周春辉
Original assignee: 6th Medical Center of PLA General Hospital
Current assignee: 6th Medical Center of PLA General Hospital
Priority date: 2025-03-19
Filing date: 2025-03-19
Publication date: 2025-09-23
Anticipated expiration: 2045-03-19
Also published as: CN119867935A

Abstract

The application discloses a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measuring device and a method. The method is applied to a control module of equipment and further comprises an endoscope module and an electromagnetic tracking module, the method comprises the steps of obtaining multi-mode image information corresponding to a fresh cadaver head to be measured, generating a three-dimensional model corresponding to the fresh cadaver head according to the multi-mode image information, obtaining a target position corresponding to a preset key anatomical structure in the three-dimensional model, wherein the key anatomical structure at least comprises one or more of nasal cavities, sinuses, blood vessels and nerves, obtaining magnetic field information sent by the electromagnetic tracking module when the endoscope module enters the nasal cavity of the fresh cadaver head, calculating the corresponding spatial position of the electromagnetic tracking module in the three-dimensional model according to the magnetic field information, generating navigation information corresponding to the endoscope module according to the spatial position and the target position, wherein the navigation information comprises direction information and distance information, and moving the endoscope module to the target position according to the navigation information.

Description

Multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement equipment and method

Technical Field

The application relates to the technical field of electromagnetic navigation, in particular to a multi-mode electromagnetic navigation assisted fresh cadaver nasal endoscopic dissection measuring device and method.

Background

In the field of modern medicine, particularly otorhinolaryngology and neurosurgery, transnasal endoscopic surgery (Endoscopic Endonasal Approach, EEA) has become an important minimally invasive surgical technique. EEA enters the skull base through the nasal cavity and can be used for treating various diseases, such as pituitary tumor, meningioma and the like. However, due to the complex anatomy of the nasal cavity and sinus and the large individual variability, a highly accurate navigational positioning system is required during surgery to ensure the safety and effectiveness of the surgery.

Conventional navigation systems rely primarily on pre-operative image data (e.g., CT and MRI) for localization, but these systems suffer from the following limitations:

1. the image registration accuracy is low, and the registration error between the image data of different modes is larger, so that the navigation accuracy is influenced.

2. The real-time feedback is insufficient, and the traditional system lacks real-time dynamic updating capability and cannot be adjusted according to the change in the operation process.

3. The operation is complicated, key anatomical structures need to be marked manually, and the workload of doctors is increased.

4. Safety problems in complex environments, stability and reliability of the system are difficult to ensure.

There is therefore a need for a multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement device and method that addresses at least one of the problems described above.

Disclosure of Invention

The application provides a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement device and method, and aims to solve the problems that a traditional navigation system mainly depends on preoperative image data (such as CT and MRI) for positioning, but the systems have the limitations of low image registration accuracy, insufficient real-time feedback, complex operation, safety and the like.

In a first aspect, the application provides a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement method, which is applied to a control module of a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement device, the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement device further comprises an endoscope module and an electromagnetic tracking module, the front end of the endoscope module is used for extending into a nasal cavity of a fresh cadaver head to be measured, and the electromagnetic tracking module is arranged at the front end of the endoscope module and is used for measuring magnetic field information of the nasal cavity, and the method comprises the following steps:

acquiring multi-mode image information corresponding to a fresh cadaver to be measured, wherein the multi-mode image information at least comprises CT image information and MRI image information;

generating a three-dimensional model corresponding to the fresh cadaver according to the multi-mode image information;

Acquiring a target position corresponding to a preset key anatomical structure in the three-dimensional model, wherein the key anatomical structure at least comprises one or more of nasal cavity, nasal sinuses, blood vessels and nerves;

When the endoscope module enters the nasal cavity of the fresh cadaver head, acquiring magnetic field information sent by the electromagnetic tracking module;

Calculating the corresponding spatial position of the electromagnetic tracking module in the three-dimensional model according to the magnetic field information;

Generating navigation information corresponding to the endoscope module according to the space position and the target position, wherein the navigation information comprises direction information and distance information;

And moving the endoscope module to the target position according to the navigation information.

In some embodiments, the generating the three-dimensional model corresponding to the fresh cadaver according to the multi-mode image information comprises the steps of carrying out initial registration and fine registration on the CT image information and the MRI image information, respectively inputting the CT image information and the MRI image information into a pre-trained multi-task segmentation model to complete automatic segmentation of the CT image information and the MRI image information, respectively obtaining segmentation information corresponding to the CT image information and the MRI image information, respectively generating a CT three-dimensional model and an MRI three-dimensional model according to the segmentation information corresponding to the CT image information and the MRI image information, respectively generating a plurality of tag information corresponding to the CT three-dimensional model and the MRI three-dimensional model based on a natural language processing technology, completing fusion of the CT three-dimensional model and the MRI three-dimensional model according to the tag information, and obtaining the three-dimensional model corresponding to the fresh cadaver.

Illustratively, the method further comprises preprocessing the CT image information and the MRI image information before the initial registration and the fine registration of the CT image information and the MRI image information respectively, wherein the preprocessing comprises noise removal, normalization and slice alignment.

The method comprises the steps of respectively obtaining characteristic point information corresponding to CT image information and MRI image information, carrying out rigid transformation on the CT image information and the MRI image information according to the characteristic point information to finish initial registration of the CT image information and the MRI image information, and carrying out thin-plate spline transformation on the CT image information and the MRI image information to finish fine registration.

The method comprises the steps of obtaining surface grids from the binary image, adjusting the density of the surface grids according to the local feature data, and generating the CT three-dimensional model and the MRI three-dimensional model according to the voxel data and the surface grids corresponding to the CT image information and the MRI image information respectively based on a ray projection algorithm.

The method comprises the steps of obtaining a structural identifier corresponding to each piece of label information, determining fusion weights corresponding to the local areas according to the structural information, determining fusion weights corresponding to the local areas if the structural identifier is a bone, determining fusion weights corresponding to the local areas of the CT three-dimensional model to be greater than fusion weights corresponding to the local areas of the MRI three-dimensional model if the structural identifier is a soft tissue, determining fusion weights corresponding to the local areas of the CT three-dimensional model to be less than fusion weights corresponding to the local areas of the MRI three-dimensional model, and completing fusion of the CT three-dimensional model and the MRI three-dimensional model according to the fusion weights.

In some embodiments, the electromagnetic tracking module comprises a magnetic field generator and an electromagnetic tracking sensor, wherein the electromagnetic tracking sensor is arranged at the front end of the endoscope module, the magnetic field generator is arranged outside the fresh cadaver head and is used for generating an external magnetic field, the calculating of the corresponding spatial position of the electromagnetic tracking module in the three-dimensional model according to the magnetic field information comprises the steps of obtaining distribution information corresponding to the external magnetic field and calculating the spatial position according to the distribution information and the magnetic field information.

The method for calculating the space position according to the distribution information and the magnetic field information comprises the steps of obtaining the generator position and the magnetic moment of the magnetic field generator, constructing a magnetic field intensity model corresponding to the electromagnetic tracking sensor according to the generator position and the magnetic moment of the magnetic field generator, and reversely solving and calculating the space position in the magnetic field intensity model according to the magnetic field information.

It should be noted that, in some embodiments, the calculating the spatial position according to the magnetic field information by inverse solution in the magnetic field intensity model includes obtaining a corresponding magnetic field intensity value according to the magnetic field information, calculating the spatial position according to the distribution information and the magnetic field intensity value by inverse solution in the magnetic field intensity model, and the expression of the magnetic field intensity model includes:

;

Wherein, the For the model of the magnetic field strength,For the value of the magnetic field strength,For the spatial position corresponding to the electromagnetic tracking sensor,For the location of the generator(s),As a difference coefficient between the spatial position and the generator position,Is the magnetic permeability of the vacuum and is equal to the magnetic permeability of the vacuum,Is the magnetic moment.

In a second aspect, the present application provides a multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement device comprising:

The front end of the endoscope module is used for extending into the nasal cavity of a fresh cadaver head to be measured;

The electromagnetic tracking module is arranged at the front end of the endoscope module and is used for measuring magnetic field information of the nasal cavity;

The system comprises a control module, a storage and a processor, wherein the control module comprises a memory and a processor, the memory is used for storing a computer program, and the processor is used for executing the computer program and realizing the steps of the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement method according to the first aspect.

The application discloses a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measuring device and a method. The multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement method mainly comprises the following steps and technical points:

Firstly, multi-mode image information of a fresh cadaver head to be measured is acquired, wherein the image information at least comprises CT images and MRI images. The two imaging technologies can provide complementary information, the CT image can clearly display the bone structure, and the MRI image has better resolution capability on soft tissues, blood vessels, nerves and the like.

Then, a detailed three-dimensional anatomical model is generated by computer processing using the multi-modal image data obtained as described above. The model can be used as a basis for subsequent navigation, and can intuitively display the specific position and morphological characteristics of a target area (such as nasal cavity, nasal sinuses, blood vessels and nerves).

Further, critical anatomical sites that require significant attention, such as specific sinuses, vital blood vessels or sensitive nerves, etc., are identified and labeled in the constructed three-dimensional model and their exact coordinates are recorded. When the endoscope module is inserted into the nasal cavity of the cadaver head, the electromagnetic tracking device at the front end of the endoscope module starts to work, continuously monitors the magnetic field change condition in the surrounding environment, and transmits the collected data to the control system.

Furthermore, based on the signals received from the electromagnetic sensor, the system can accurately calculate the space coordinates of the front end of the current endoscope and map the space coordinates to the three-dimensional digital model established before.

Finally, according to the relative relation between the current position and the preset target, the system automatically generates corresponding navigation advice to tell the operator which direction to move next and how much distance to advance to reach the destination. And adjusting the position of the endoscope according to the provided guiding information until the endoscope successfully arrives at the appointed place to finish the measurement task.

The method creates a high-precision three-dimensional reconstruction model by combining a plurality of imaging technologies, and realizes accurate space positioning by adopting an advanced electromagnetic positioning technology, thereby greatly improving the capability of identifying a microstructure in the operation process. Compared with the traditional method relying on static image data, the scheme can provide instant feedback in the operation process, and is helpful for avoiding the risk of accidentally injuring important organs or tissues. The whole process has higher automation degree, reduces errors caused by human factors, and enables even complex and fine operation to be easier to master.

At the same time, the device to which the method is applied is provided for the user to not only assist them in better understanding the human anatomy, but also to allow them to practice adequately before the actual operation.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application as claimed.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present application, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of steps of a multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement method provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of a scenario corresponding to a method according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic measurement device according to an embodiment of the present application;

fig. 4 is a schematic block diagram of a control module according to an embodiment of the present application.

Detailed Description

The following description of the embodiments of the present application will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are some, but not all embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The flow diagrams depicted in the figures are merely illustrative and not necessarily all of the elements and operations/steps are included or performed in the order described. For example, some operations/steps may be further divided, combined, or partially combined, so that the order of actual execution may be changed according to actual situations.

It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, the words "first", "second", etc. are used to distinguish identical items or similar items having substantially the same function and effect. It will be appreciated by those of skill in the art that the words "first," "second," and the like do not limit the amount and order of execution, and that the words "first," "second," and the like do not necessarily differ.

It is to be understood that the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should also be understood that the term "and/or" as used in the present specification and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes such combinations.

Some embodiments of the present application are described in detail below with reference to the accompanying drawings. The following embodiments and features of the embodiments may be combined with each other without conflict.

In order to solve the above-mentioned problems, please refer to fig. 1, fig. 1 is a schematic flow chart of a multi-modal electromagnetic navigation assisted nasosinusitis measurement method according to an embodiment of the present application. The method is applied to a control module of the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measuring equipment, the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measuring equipment further comprises an endoscope module and an electromagnetic tracking module, the front end of the endoscope module is used for extending into a nasal cavity of a fresh cadaver head to be measured, and the electromagnetic tracking module is arranged at the front end of the endoscope module and is used for measuring magnetic field information of the nasal cavity.

To solve the above problems, please refer to fig. 1. Specifically, as shown in fig. 1, the provided method includes steps S101 to S107. The details are as follows:

S101, acquiring multi-mode image information corresponding to a fresh cadaver head to be measured, wherein the multi-mode image information at least comprises CT image information and MRI image information.

Specifically, first, detailed image data of a fresh cadaver head is acquired by imaging techniques such as CT (computed tomography) and MRI (magnetic resonance imaging). These image data may provide different levels and types of anatomical information such as bone structure, soft tissue distribution, and the location of blood vessels and nerves. For example, a high resolution CT scanner is used to obtain detailed bone structure images of nasal cavity and surrounding area, and MRI equipment is used to obtain soft tissue images of the same area, including nasal sinuses, blood vessels, nerves, etc. The multi-mode image information can provide more comprehensive and more detailed anatomical structure information, and is helpful for improving the precision of three-dimensional model construction in the subsequent steps.

S102, generating a three-dimensional model corresponding to the fresh cadaver head according to the multi-mode image information.

Specifically, the image data of different modalities obtained from S101 are subjected to fusion processing, and a comprehensive three-dimensional anatomical model is generated by using medical image processing software or algorithm (e.g., a method based on deep learning). The CT and MRI data are aligned and combined, for example, using advanced image registration techniques, to generate a three-dimensional model containing bone, soft tissue, blood vessels, nerves, and the like. The three-dimensional model provides visual and accurate reference basis for subsequent operation planning, and improves the safety and accuracy of operation.

Such as DICOM data based on CT/MRI, a Marching Cubes algorithm or a deep learning model (e.g., 3D U-Net) is used to generate a fused three-dimensional model containing bones, vessels, nerves. Mesh smoothing and topology restoration is performed by MeshLab. By reconstructing the nasopharynx three-dimensional model, the interval between the carotid artery and the optic nerve tube can be marked by interactive rotary scaling. And the manual marking is replaced, a panoramic anatomical view is provided, and the cognitive load of doctors is reduced.

For example, the CT bone segmentation is performed by thresholding to extract voxels (corresponding to bone tissue) of 200HU or more. MRI vessel segmentation enhances the tubular structure by Frangi filters, and extracts vessels in combination with region growing. Surface reconstruction by applying Marching Cubes algorithm to the CT data, the iso-surface threshold is set to 150HU. Topology repair is carried out on the MRI blood vessel by using a 3D Residual U-Net, an STL format grid is output, the size of a triangular patch is less than or equal to 0.1mm, and curvature smoothing iterates 5 times. The diameter error of the reconstructed internal carotid artery three-dimensional model is less than or equal to 0.15mm (compared with microdissection measurement). Realizing multi-tissue fusion modeling, achieving the blood vessel modeling accuracy reaching the sub-millimeter level, and supporting accurate avoidance in operation

S103, acquiring a target position corresponding to a preset key anatomical structure in the three-dimensional model, wherein the key anatomical structure at least comprises one or more of nasal cavity, nasal sinuses, blood vessels and nerves.

Specifically, on the constructed three-dimensional model, key anatomical structures and specific position coordinates thereof which need to be focused are marked by professionals or automatic recognition algorithms. For example, a doctor marks key points such as a nasal cavity inlet, various nasal sinus openings, important blood vessel paths, nerve trend and the like in a three-dimensional model manually or by means of an intelligent tool. The definition of the target position is beneficial to making a more accurate operation plan and ensuring that important organs are not damaged in the actual operation process.

S104, when the endoscope module enters the nasal cavity of the fresh cadaver head, acquiring magnetic field information sent by the electromagnetic tracking module.

Specifically, after the front end of the endoscope is inserted into the nasal cavity of a patient, an electromagnetic sensor arranged on the endoscope starts to work, continuously monitors the magnetic field change condition in the environment, and transmits the collected data to a control system in real time. Along with the endoscope penetrating into the nasal cavity, a miniature electromagnetic sensor carried at the front end of the endoscope continuously detects the intensity and direction change of a magnetic field in a surrounding space. By monitoring the magnetic field information in real time, the system can accurately grasp the current specific position of the endoscope, thereby realizing the dynamic positioning function.

Meanwhile, as shown in fig. 2, the method can automatically generate the distance between the probe and the two points of the anterior traffic artery by using a flexible navigation probe (a red part probe corresponding to the mark 4 in fig. 2) such as marking the left and right end points of the anterior traffic artery.

S105, calculating the corresponding spatial position of the electromagnetic tracking module in the three-dimensional model according to the magnetic field information.

Specifically, based on the received magnetic field data, the exact coordinates of the electromagnetic tracking device relative to the three-dimensional anatomical model are calculated by utilizing a specific algorithm in combination with a pre-established magnetic field distribution map. Assuming that the standard magnetic field value at a fixed point a is known as B ₀ and the actual value currently measured is B ₁, the relative displacements Δx, Δy, Δz between the current positions P and a can be back-deduced from the difference between the two. This process enables a high level of position tracking accuracy to be maintained even in complex environments, enhancing the overall reliability of the system.

S106, generating navigation information corresponding to the endoscope module according to the space position and the target position, wherein the navigation information comprises direction information and distance information.

Specifically, the difference between the current endoscope position and the target position set before is compared, and a navigation guide comprising an advancing direction indication and a distance prompt is generated. If the target point is positioned at the front right side by 5cm, outputting a command of deflecting to the right by 10 degrees and continuing to advance by 5 cm. The clear navigation guidance is helpful for the operator to quickly and accurately reach the preset destination, and the risk brought by blind searching is reduced.

Navigation information generation can be achieved by improving the a-algorithm, cost function:

;

as a function of the cost, As risk weight, risk functionBased on the vessel/nerve proximity calculation,Representing from a starting node to a current nodeTo a real cost (or cost). This value is typically calculated by accumulating the actual movement costs of each step from the starting point to the current node.Representing slave current nodesEstimated cost to target node (heuristic function).

Representing a current nodeFor evaluating the security when passing the node. The risk value may be calculated based on factors such as proximity of the anatomy, tissue type, and the like. The expression may include:

。

Is a node And the firstThe distance of the individual critical anatomical structures,Is a small constant (e.g., 0.01) that prevents the denominator from being zero.

And S107, moving the endoscope module to the target position according to the navigation information.

Specifically, the pose and the travel route of the endoscope are adjusted according to the navigation advice provided in S106 until the specified target anatomical site is reached. And gradually trimming the angle and the length of the endoscope according to the arrow pointing and the distance values on the display screen, and finally enabling the tip of the endoscope to contact with a pre-calibrated key structure. The whole process realizes the effective connection from static planning to dynamic execution, and greatly improves the operation efficiency and success rate.

The CT image information and the MRI image information are preprocessed prior to initial registration and fine registration. The preprocessing step comprises noise removal, namely removing noise in the image by using a filtering technology (such as median filtering, gaussian filtering and the like) and improving the image quality. And (3) standardization, namely adjusting the image data of different modes to a uniform gray scale range or intensity range so as to facilitate subsequent processing. Slice alignment, namely ensuring that the slices of CT and MRI images are aligned in space, and avoiding registration errors caused by inconsistent slice positions.

By removing noise, interference factors can be reduced, and the image is clearer. The standardized processing enables the data of different modes to be comparable, and subsequent registration and fusion are facilitated. The slice alignment ensures the corresponding relation of different mode images in space, and improves the registration accuracy.

Key feature points are extracted from the CT image information and the MRI image information, which feature points are typically salient points in the anatomical structure. And (3) performing rigid transformation (translation and rotation) on the CT image information and the MRI image information according to the extracted characteristic point information, and completing initial registration. Based on the initial registration, the CT image information and the MRI image information are further subjected to fine registration by using a thin plate spline transformation (a nonlinear transformation method) so as to eliminate errors caused by local deformation.

Through feature point matching and rigid transformation, the approximate corresponding relation between the two modal images can be quickly found. The thin plate spline transformation can finely adjust the corresponding relation of the local area, and further improves the registration accuracy, so that a more accurate three-dimensional model is generated.

The segmentation information includes voxel data, binary images, and local feature data. A surface mesh is extracted from the binary image, representing the surface of the anatomical structure. The density of the surface mesh is adjusted according to the local feature data to better reflect the details of the anatomy. Based on a ray casting algorithm, combining voxel data and a surface grid to respectively generate a CT three-dimensional model and an MRI three-dimensional model.

By combining voxel data with a surface mesh, a more detailed and accurate three-dimensional model can be generated. The grid density can be adjusted to optimize according to the importance of different areas, and the detail performance of the model is improved. The light projection algorithm is an efficient three-dimensional reconstruction method, and can generate a high-quality three-dimensional model in a short time.

The tag information corresponds to a local region in the CT three-dimensional model or the MRI three-dimensional model. And obtaining a structure identifier (such as bones, soft tissues and the like) corresponding to each tag information. If the structural identifier is bone, the fusion weight corresponding to the local area of the CT three-dimensional model is greater than the fusion weight corresponding to the local area of the MRI three-dimensional model. If the structure is identified as soft tissue, the fusion weight corresponding to the local area of the CT three-dimensional model is smaller than that of the MRI three-dimensional model. And fusing the CT three-dimensional model and the MRI three-dimensional model according to the fusion weight to generate a comprehensive three-dimensional model.

By different fusion weights, the dominant part of each modality, such as the advantages of CT in bone imaging and MRI in soft tissue imaging, can be better preserved. The comprehensive three-dimensional model can provide more comprehensive and detailed anatomical information, and is beneficial to improving the accuracy of operation planning and navigation. The fused model can better meet clinical requirements and provide a more reliable and practical reference basis.

The electromagnetic tracking module comprises a magnetic field generator and an electromagnetic tracking sensor. The magnetic field generator is arranged outside the fresh cadaver head and is used for generating an external magnetic field. The electromagnetic tracking sensor is arranged at the front end of the endoscope module and used for measuring magnetic field information in the nasal cavity.

By means of the known position and magnetic moment of the magnetic field generator, a distribution model of the external magnetic field is constructed. And calculating the accurate position of the electromagnetic tracking sensor in the three-dimensional model by using the magnetic field distribution information and the actually measured magnetic field information.

By the cooperation of the external magnetic field generator and the internal sensor, high-precision space positioning can be realized. The position change of the endoscope can be monitored in real time, the dynamic updating capability is provided, and the accuracy of surgical navigation is improved. The manual marking and adjusting workload is reduced, and the operation efficiency and the safety are improved.

By determining the specific location and magnetic moment of the magnetic field generator. And constructing a magnetic field intensity model corresponding to the electromagnetic tracking sensor according to the position and the magnetic moment of the magnetic field generator. And according to the actually measured magnetic field information, the spatial position of the electromagnetic tracking sensor is calculated by inverse solution in the magnetic field intensity model.

By constructing a detailed magnetic field intensity model, the magnetic field distribution can be more accurately described, and the positioning accuracy is improved. The inverse solving method can reversely deduce the specific position of the sensor from the actual measured value, and ensure the positioning accuracy. The method supports real-time calculation, can dynamically adjust the position of the endoscope in the operation process, and improves the flexibility and reliability of navigation.

;

The actual measured magnetic field strength value is obtained from the electromagnetic tracking sensor. And according to the magnetic field distribution information and the actually measured magnetic field intensity value, the space position of the electromagnetic tracking sensor is calculated by inverse solution in the magnetic field intensity model. Through a specific mathematical model, the spatial position of the electromagnetic tracking sensor can be accurately calculated. The inverse solving method based on the magnetic field intensity model can realize high-precision spatial positioning and reduce errors. The method supports real-time calculation, can dynamically adjust the position of the endoscope in the operation process, and improves the real-time performance and accuracy of navigation. The use of the mathematical model enables the positioning process to be more stable and reliable, and reduces the influence of environmental factors on the positioning result.

Referring to fig. 3, fig. 3 is a schematic structural diagram of a multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement device 200 according to an embodiment of the present application. The multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic measurement apparatus 200 is used to perform the steps of the multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic measurement method shown in the above embodiments. The multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic dissection measurement device 200 may be a single server or a cluster of servers, or the multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic dissection measurement device 200 may be a terminal, which may be a handheld terminal, a notebook computer, a wearable device, a robot or the like.

As shown in fig. 3, the multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement device 200 includes:

a multimode acquisition unit 201, configured to acquire multimode image information corresponding to a fresh cadaver to be measured, where the multimode image information includes at least CT image information and MRI image information;

A three-dimensional generating unit 202, configured to generate a three-dimensional model corresponding to the fresh cadaver according to the multi-mode image information;

A position obtaining unit 203, configured to obtain a target position corresponding to a preset key anatomical structure in the three-dimensional model, where the key anatomical structure at least includes one or more of a nasal cavity, a nasal sinus, a blood vessel, and a nerve;

an information obtaining unit 204, configured to obtain magnetic field information sent by the electromagnetic tracking module when the endoscope module enters the nasal cavity of the fresh cadaver head;

a space acquisition unit 205, configured to calculate a spatial position corresponding to the electromagnetic tracking module in the three-dimensional model according to the magnetic field information;

a navigation generating unit 206, configured to generate navigation information corresponding to the endoscope module according to the spatial position and the target position, where the navigation information includes direction information and distance information;

a target moving unit 207 for moving the endoscope module to the target position according to the navigation information.

;

It should be noted that, for convenience and brevity of description, the specific working process of the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic measurement device and each unit described above may refer to the corresponding process in the multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic measurement embodiment described in each embodiment described above, which is not described herein again.

The above-described multimodal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurement may be implemented in the form of a computer program which may be run on a device as shown in fig. 3.

The embodiment of the application provides a multi-mode electromagnetic navigation assisted fresh cadaver head transnasal endoscopic dissection measurement device which comprises an endoscope module, an electromagnetic tracking module and a control module, wherein the front end of the endoscope module is used for extending into the nasal cavity of a fresh cadaver head to be measured, the electromagnetic tracking module is arranged at the front end of the endoscope module and is used for measuring magnetic field information of the nasal cavity, the control module comprises a memory and a processor, the memory is used for storing a computer program, and the processor is used for executing the computer program and realizing the method according to any one of the above steps when executing the computer program.

The front end of the endoscope module is designed to be capable of extending into the nasal cavity of a fresh cadaver head, and is usually provided with a high-definition camera and an illumination system so as to provide clear visual feedback in the operation process. The endoscope module is used for observing the internal structure of the nasal cavity and transmitting real-time images to the control module through the camera.

The electromagnetic tracking module is disposed at the front end of the endoscope module, typically a small sensor. For measuring magnetic field information in the nasal cavity. The magnetic field information is generated by an external magnetic field generator and the sensor determines its position in three-dimensional space by detecting the magnetic field information.

The control module is used for storing information such as computer programs, multi-mode image data, three-dimensional models and the like. The processor executes a computer program stored in memory to perform the functions of acquiring multi-modality image information (e.g., CT and MRI) and generating a three-dimensional model. Target locations of key anatomical structures are labeled in the three-dimensional model. And calculating the spatial position of the electromagnetic tracking module in the three-dimensional model according to the magnetic field information sent by the electromagnetic tracking module. Navigation information is generated, including direction information and distance information. The endoscope module is controlled to move to a target position.

Such as using a high resolution CT scanner to acquire detailed bony structure images of the nasal cavity and surrounding areas, while using MRI equipment to acquire soft tissue images of the same area. The CT and MRI image data are preprocessed, including noise removal, normalization, and slice alignment, followed by initial registration and fine registration.

Feature point information is extracted from CT and MRI images, rigid transformation is carried out to finish initial registration, and then thin plate spline transformation is carried out to finish fine registration. And generating a CT three-dimensional model and an MRI three-dimensional model according to the segmentation information (voxel data, binary image and local feature data), and finally fusing to generate a comprehensive three-dimensional model.

An external magnetic field generator generates a magnetic field with known distribution, and an electromagnetic tracking sensor at the front end of the endoscope measures actual magnetic field information. And constructing a magnetic field intensity model according to the position and magnetic moment of the magnetic field generator, and calculating the spatial position of the sensor by inverse solution. Navigation information, including direction information and distance information, is generated from the spatial position of the sensor and the pre-labeled key anatomical structure target position. And adjusting the posture and the travel route of the endoscope module according to the navigation information until reaching the preset target position.

By means of the three-dimensional model generated by the multi-mode image data and the electromagnetic tracking technology, high-precision space positioning can be achieved, and errors in the operation process are reduced. The electromagnetic tracking module can monitor the position change of the endoscope in real time, provide dynamic updating capability and ensure the timeliness and accuracy of navigation information. Automated image processing and navigation information generation reduces the workload of manual marking and adjustment, and improves the operating efficiency. The high-precision positioning and real-time feedback are helpful to avoid damaging important organs, and the safety and success rate of the operation are improved. The multi-modal image data provides more comprehensive and detailed anatomical information, which is helpful for making a more accurate operation plan. By dynamically adjusting the position of the endoscope, the stability and the reliability of the system can be kept under a complex environment, and different operation requirements can be met.

The multi-mode electromagnetic navigation assists the fresh cadaver head transnasal endoscopic dissection measuring equipment to realize high-precision, real-time feedback and automatic operation navigation through the cooperative work of the endoscope module, the electromagnetic tracking module and the control module. The device not only improves the safety and success rate of the operation, but also simplifies the operation flow, lightens the workload of doctors, and has wide application prospect.

Referring to fig. 4, fig. 4 is a schematic block diagram of a control module according to an embodiment of the present application. The control module includes a processor, a memory, and a network interface connected by a device bus, where the memory may include a storage medium and an internal memory.

The storage medium may store an operating device and a computer program. The computer program comprises program instructions that, when executed, cause the processor to perform any of a number of multi-modal electromagnetic navigation assisted fresh cadaver transnasal endoscopic anatomical measurements.

The processor is used to provide computing and control capabilities, supporting the operation of the overall control module.

The internal memory provides an environment for the execution of a computer program in a non-volatile storage medium that, when executed by the processor, causes the processor to perform any of a number of multi-modal electromagnetic navigation assisted nasolacrimal endoscopic anatomical measurements.

The network interface is used for network communication such as transmitting assigned tasks and the like. It will be appreciated by those skilled in the art that the structure shown in fig. 4 is merely a block diagram of a portion of the structure associated with the present inventive arrangements and is not limiting of the terminal to which the present inventive arrangements are applied, and that a particular control module may include more or fewer components than shown, or may combine certain components, or have a different arrangement of components.

It should be appreciated that the Processor may be a central processing unit (Central Processing Unit, CPU), it may also be other general purpose processors, digital signal processors (DIGITAL SIGNAL Processor, DSP), application SPECIFIC INTEGRATED Circuit (ASIC), field-Programmable gate array (Field-Programmable GATE ARRAY, FPGA) or other Programmable logic device, discrete gate or transistor logic device, discrete hardware components, or the like. Wherein the general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

Wherein in one embodiment the processor is configured to run a computer program stored in the memory to implement the steps of:

;

It should be noted that, for convenience and brevity of description, specific working processes of the processor described above may refer to corresponding processes in the embodiment of the multi-mode electromagnetic navigation assisted nasosinusitis measurement of fresh cadaver head described in the above embodiments, and will not be repeated here.

An embodiment of the present application further provides a computer readable storage medium, where the computer readable storage medium stores a computer program, where the computer program includes program instructions, and the processor executes the program instructions to implement the steps of the multi-mode electromagnetic navigation assisted fresh cadaver head intranasal endoscopic dissection measurement method provided by the foregoing embodiments of the present application.

The computer readable storage medium may be an internal storage unit of the control module according to the foregoing embodiment, for example, a hard disk or a memory of the control module. The computer readable storage medium may also be an external storage device of the control module, such as a plug-in hard disk, a smart memory card (SMART MEDIA CARD, SMC), a Secure Digital (SD) card, a flash memory card (FLASH CARD), or the like, which are provided on the control module.

While the application has been described with reference to certain preferred embodiments, it will be understood by those skilled in the art that various changes and substitutions of equivalents may be made and equivalents will be apparent to those skilled in the art without departing from the scope of the application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A multimodal electromagnetic navigation-assisted transnasal endoscopic anatomical measurement method for a fresh cadaver head, characterized in that the method is applied to a multimodal electromagnetic navigation-assisted transnasal endoscopic anatomical measurement device for a fresh cadaver head, the device comprising a control module, an endoscope module, and an electromagnetic tracking module. The front end of the endoscope module is configured to extend into the nasal cavity of the fresh cadaver head to be measured. The electromagnetic tracking module is disposed at the front end of the endoscope module and is configured to measure magnetic field information of the nasal cavity.

The method comprises:

Acquiring multimodal image information corresponding to a fresh cadaver head to be measured, wherein the multimodal image information includes at least CT image information and MRI image information;

The three-dimensional model corresponding to the fresh corpse head is generated according to the multimodal image information, including: performing initial registration and fine registration on the CT image information and the MRI image information; inputting the CT image information and the MRI image information into a pre-trained multi-task segmentation model respectively to complete automatic segmentation of the CT image information and the MRI image information, and obtaining segmentation information corresponding to the CT image information and the MRI image information respectively; generating a CT three-dimensional model and an MRI three-dimensional model according to the segmentation information corresponding to the CT image information and the MRI image information respectively; generating a plurality of label information corresponding to the CT three-dimensional model and the MRI three-dimensional model respectively based on natural language processing technology; the label information is stored in the CT three-dimensional model or the MRI three-dimensional model. I three-dimensional model corresponds to a local area; completing the fusion of the CT three-dimensional model and the MRI three-dimensional model according to the label information, including: obtaining a structure identifier corresponding to each of the label information; determining a fusion weight corresponding to the local area according to the structure identifier; if the structure identifier is bone, the fusion weight corresponding to the local area of the CT three-dimensional model is greater than the fusion weight corresponding to the local area of the MRI three-dimensional model; if the structure identifier is soft tissue, the fusion weight corresponding to the local area of the CT three-dimensional model is less than the fusion weight corresponding to the local area of the MRI three-dimensional model; completing the fusion of the CT three-dimensional model and the MRI three-dimensional model according to the fusion weight; obtaining a three-dimensional model corresponding to the fresh cadaver head;

Obtaining a target position corresponding to a preset key anatomical structure in the three-dimensional model; the key anatomical structure includes at least one or more of a nasal cavity, a paranasal sinus, a blood vessel, and a nerve;

When the endoscope module enters the nasal cavity of the fresh cadaver, obtaining magnetic field information sent by the electromagnetic tracking module;

generating navigation information corresponding to the endoscope module according to the spatial position and the target position, the navigation information including direction information and distance information;

The endoscope module is moved to the target position according to the navigation information.

2. The method according to claim 1, characterized in that before performing initial registration and fine registration on the CT image information and the MRI image information, the method further comprises:

The CT image information and the MRI image information are preprocessed; the preprocessing includes noise removal, standardization and slice alignment.

3. The method according to claim 1, wherein the performing initial registration and fine registration on the CT image information and the MRI image information respectively comprises:

Respectively obtaining feature point information corresponding to the CT image information and the MRI image information;

Performing a rigid transformation on the CT image information and the MRI image information according to the feature point information to complete initial registration of the CT image information and the MRI image information;

The CT image information and the MRI image information are subjected to thin plate spline transformation to complete the fine registration.

4. The method according to claim 1, wherein the segmentation information includes voxel data, a binary image, and local feature data; and generating a CT 3D model and an MRI 3D model based on the segmentation information corresponding to the CT image information and the MRI image information, respectively, comprises:

obtaining a surface mesh from the binary image;

adjusting the density of the surface mesh according to the local feature data;

The CT three-dimensional model and the MRI three-dimensional model are generated based on the voxel data and surface mesh corresponding to the CT image information and the MRI image information respectively based on a ray casting algorithm.

5. The method according to claim 1, wherein the electromagnetic tracking module comprises a magnetic field generator and an electromagnetic tracking sensor, wherein the electromagnetic tracking sensor is disposed at the front end of the endoscope module, and the magnetic field generator is disposed outside the fresh cadaver head to generate an external magnetic field;

Calculating the spatial position corresponding to the electromagnetic tracking module in the three-dimensional model according to the magnetic field information includes:

Obtaining distribution information corresponding to the external magnetic field;

The spatial position is calculated according to the distribution information and the magnetic field information.

6. The method according to claim 5, wherein calculating the spatial position according to the distribution information and magnetic field information comprises:

obtaining a generator position and a magnetic moment of the magnetic field generator;

Constructing a magnetic field intensity model corresponding to the electromagnetic tracking sensor according to the generator position and magnetic moment of the magnetic field generator;

The spatial position is calculated by reversely solving the magnetic field strength model according to the magnetic field information.

7. The method according to claim 6, wherein the step of calculating the spatial position by inversely solving the magnetic field strength model based on the magnetic field information comprises:

Acquire a corresponding magnetic field intensity value according to the magnetic field information;

The spatial position is calculated by reversely solving the magnetic field strength model according to the distribution information and the magnetic field strength value; the expression of the magnetic field strength model includes:

;

in, is the magnetic field strength model, is the magnetic field strength value, is the spatial position corresponding to the electromagnetic tracking sensor, is the generator position, is the difference coefficient between the spatial position and the generator position, is the vacuum permeability, is the magnetic moment.

8. A multimodal electromagnetic navigation-assisted transnasal endoscopic anatomical measurement device for a fresh cadaver head for implementing the method according to any one of claims 1 to 7, comprising:

an endoscope module, the front end of which is used to extend into the nasal cavity of a fresh cadaver to be measured;

an electromagnetic tracking module, which is disposed at the front end of the endoscope module and is used to measure magnetic field information of the nasal cavity;

A control module includes a memory and a processor; the memory is used to store computer programs; and the processor is used to execute the computer programs.