Tumor ablation integrated system based on unified space coordinate framework and working method thereof

Abstract

The invention provides a tumor ablation integrated system based on a unified space coordinate framework and a working method thereof. According to the system and the working method thereof, a preoperative temperature field and necrosis prediction are generated through multi-physical field simulation, geometric guidance in an operation is realized through augmented reality navigation, a three-dimensional thermal field in the operation is constructed based on CT temperature measurement, and data fusion and dynamic closed loop are realized through a unified coordinate framework, so that full-flow visualization and controllability of a tumor ablation process are realized; the thermal ablation puncture precision, the thermal dose control precision and the information transparency in the operation are improved.

Description

TECHNICAL FIELD

[0001] The application provides a tumor ablation integrated system based on a unified spatial coordinate framework and a working method thereof, and relates to the technical fields of image navigation, energy field modeling and thermal therapy control. BACKGROUND

[0002] As a local thermal treatment method, tumor thermal ablation technology (such as microwave ablation and radiofrequency ablation) has been widely used in the clinical treatment of solid tumors such as liver, kidney and lung. Thermal ablation can make the local tissue temperature rise and induce irreversible coagulation necrosis by applying high-frequency energy in the tumor tissue, so as to achieve the purpose of tumor treatment. However, the curative effect of thermal ablation is highly dependent on the accurate control of the puncture path, the needle tip landing position and the ablation range by the operator.

[0003] The prior art mainly has the following deficiencies: firstly, preoperative planning lacks energy domain support and has limited prediction ability. The current preoperative needle arrangement planning usually relies on two-dimensional images or simple geometric measurements to evaluate the needle position and the expected ablation range, and lacks quantitative analysis of temperature field, SAR (specific absorption rate) distribution and tissue thermal damage. Although finite element multi-physical field simulation can simulate electromagnetic energy deposition, temperature field evolution and necrosis range before operation, it lacks a spatial fusion mechanism with intraoperative navigation and CT real-time images, and is mostly used as a separate estimation method. Secondly, intraoperative navigation mostly stays in the "geometric domain guidance" and cannot reflect the energy distribution. Augmented reality (AR), optical navigation and electromagnetic navigation are mainly used to guide the operator to make the actual puncture trajectory consistent with the planned path, but they cannot real-time present the dynamic changes of ablation energy distribution, local temperature change and ablation boundary, and are difficult to assist in judging whether additional energy or supplementary puncture is needed. Thirdly, the intraoperative ablation thermal field is invisible and lacks real-time temperature feedback mechanism. Thermal field monitoring is the key to the safety and curative effect control of thermal ablation. Although the current feasible MR thermal imaging has high accuracy, it has high cost, high equipment requirement and limited real-time performance. Ultrasound echo change monitoring is easily affected by bubbles and has weak quantitative ability. CT temperature measurement has potential thermal monitoring ability as the CT value (HU) changes regularly with temperature, but the existing CT temperature measurement method has not established an integrated HU-temperature calibration mechanism suitable for the surgical procedure, cannot be real-time fused with the surgical scene or AR navigation in a unified coordinate system, and lacks a complete three-dimensional temperature inversion and isotherm construction process, resulting in that its engineering application in real-time thermal dose visualization is not mature. In addition, the lack of a unified spatial coordinate framework leads to the inconsistent fusion of multi-source information. The preoperative simulation (analysis coordinate system), intraoperative navigation (camera coordinate / world coordinate system) and CT imaging (medical image coordinate system) are in different coordinate systems, and there is no mechanism for spatial alignment of the three, so that the energy domain (temperature, SAR), geometric domain (needle path, anatomical structure) and image domain (CT data) cannot be uniformly superimposed and presented. SUMMARY

[0004] In view of this, in order to make up for the blank and deficiency of the prior art, the application provides a tumor ablation integrated system based on a unified spatial coordinate framework and a working method thereof. The system and the working method thereof generate a preoperative temperature field and a necrosis prediction through multi-physical field simulation, realize intraoperative geometric guidance through augmented reality navigation, construct an intraoperative three-dimensional thermal field based on CT temperature measurement, realize data fusion and dynamic closed loop through a unified coordinate framework, so as to realize full-process visualization and controllability of the tumor ablation process, and improve thermal ablation puncture precision, thermal dose control precision and intraoperative information transparency.

[0005] The application provides a tumor ablation integrated system based on a unified spatial coordinate framework and a working method thereof, which includes the following contents:

[0006] The application provides a tumor ablation integrated system based on a unified spatial coordinate framework, characterized by comprising a unified spatial coordinate construction module, a preoperative planning module, an intraoperative navigation module, an intraoperative thermal field reconstruction module and a data interaction module.

[0007] The unified spatial coordinate construction module is used to realize coordinate alignment between a preoperative simulation space, a CT image space, an AR navigation space and a patient anatomy space, and to establish consistent coordinate mapping from the patient anatomy space to the preoperative simulation space to the intraoperative image space to the AR navigation space.

[0008] The preoperative planning module is used to realize thermal ablation preoperative needle arrangement planning under the unified coordinate framework, wherein the thermal ablation preoperative needle arrangement planning comprises multi-physical field model construction by using the preoperative planning module, temperature field and necrosis range prediction by using the preoperative planning module, and needle arrangement path planning by using the preoperative planning module.

[0009] The intraoperative navigation module is used to realize geometric guidance of an intraoperative puncture needle tip path and to ensure that an actual puncture path is consistent with a preoperative planning path, and comprises real-time needle tip tracking, real-time calculation and planning path deviation and provision of guidance correction information.

[0010] The intraoperative thermal field reconstruction module is used to perform real-time temperature inversion and three-dimensional thermal field visualization based on a CT image.

[0011] The data interaction module is used to realize real-time data exchange between the preoperative planning module, the intraoperative navigation module and the intraoperative thermal field reconstruction module, and is also used to realize the function of dynamically adjusting a treatment strategy according to a real-time temperature field by the tumor ablation integrated system.

[0012] Further, the uniform spatial coordinate construction module adopts a double calibration strategy, including constructing a world coordinate anchor point using a DPGS marker and mapping a simulation model to a CT coordinate system using a CT native scale and rigid registration, ultimately establishing consistent coordinate mapping from a patient anatomical space to a preoperative simulation space to an intraoperative image space to an AR navigation space and the corresponding relationship between each space, realizing the fusion display of different data sources in a uniform space.

[0013] Further, the preoperative planning module is used for multi-physical field model construction, including establishing a coupling model based on electromagnetic field distribution, biological heat conduction and tissue heat damage process; and using specific absorption rate as an electromagnetic energy deposition exogenous term to tightly couple the electromagnetic field and the heat field.

[0014] Further, the preoperative planning module is used for temperature field and necrosis range prediction, including establishing a high-precision simulation model of the tissue around the ablation needle using temperature-dependent thermal physical parameters; wherein the temperature-dependent thermal physical parameters include a three-dimensional temperature field evolution sequence, a damage integral distribution at different time points, an isosurface corresponding to a necrosis threshold, and a three-dimensional morphology of an ablation boundary and a safety boundary coverage.

[0015] Further, the preoperative planning module is used for needle placement path planning, including registering and superimposing the simulation results and the patient CT anatomical model in a three-dimensional software, and automatically generating a recommended puncture path based on the complete coverage of the tumor by the puncture path and the reservation of a 5mm safety boundary by the puncture path; and outputting the needle entry point coordinates, the needle path direction vector, the puncture depth, the ablation time and the power suggestion.

[0016] Further, the intraoperative navigation module is composed of an industrial camera, a visual marker and a rendering workstation; the intraoperative navigation module calculates the deviation from the planned path in real time according to the position of the needle tip feature point in the camera coordinate system, wherein the deviation from the planned path includes a three-dimensional position error of the needle tip and a path direction deviation angle; when the needle tip position deviates from the threshold, the intraoperative navigation module provides guidance and correction information.

[0017] Further, the intraoperative thermal field reconstruction module performs real-time temperature inversion and three-dimensional thermal field visualization based on CT images, including temperature calibration model construction, intraoperative temperature inversion and intelligent interpretation of thermal dose.

[0018] The temperature calibration model construction includes establishing a linear mapping relationship between the CT value difference caused by temperature change and the temperature through multi-temperature point experiments on ex vivo samples;

[0019] The intraoperative temperature inversion includes collecting CT volume data at a key ablation moment, performing CT value reading, temperature inversion, three-dimensional interpolation and Gaussian filtering, isothermal surface extraction, and superimposed display with the anatomical model and the planned path for each voxel;

[0020] The heat dose intelligent interpretation includes that the intraoperative heat field reconstruction module automatically calculates the distance between the 60 DEG C isothermal surface and the tumor boundary, the heat dose coverage area, the under-burning area alarm and determines whether additional ablation energy is needed.

[0021] Further, the data interaction module realizes data exchange among the preoperative planning module, the intraoperative navigation module and the intraoperative heat field reconstruction module, including establishing a complete data closed loop, wherein establishing the complete data closed loop includes that the preoperative planning module provides a needle path model for the intraoperative navigation module, the intraoperative navigation module provides a needle tip coordinate and auxiliary heat field positioning for the intraoperative heat field reconstruction module, and the intraoperative heat field reconstruction module provides heat dose results for the preoperative planning module and feeds back to the next puncture scheme optimization.

[0022] According to a second aspect of the present application, the present application provides a working method of a tumor ablation integrated system based on a unified spatial coordinate framework, which adopts the tumor ablation integrated system based on the unified spatial coordinate framework according to any one of the present application, and is characterized in that the working method of the tumor ablation integrated system based on the unified spatial coordinate framework includes the following contents:

[0023] Step S1: adopting the unified spatial coordinate construction module, fixing the DPGS marker in the surgical area, extracting the marker coordinate as a reference through CT image, and then mapping the preoperative simulation model, the anatomical model, the intraoperative image and the AR navigation space to the reference coordinate through rigid registration, so as to ensure multi-dimensional space alignment;

[0024] Step S2: adopting the preoperative planning module, importing the CT image of the patient to reconstruct the tumor anatomical model under the unified coordinate, combining physical field simulation to predict the ablation range, and designing and outputting the puncture planning path to the unified coordinate framework on the basis of completely covering the tumor in the puncture path and reserving a 5mm safety boundary in the puncture path;

[0025] Step S3: adopting the intraoperative navigation module, capturing the DPGS marker through an industrial camera under the unified coordinate, inversely solving the camera pose, superimposing the preoperative planning path and the tumor model on the surgical scene in the form of AR, and guiding the puncture operation in real time;

[0026] Step S4: adopting the intraoperative heat field reconstruction module; under the unified coordinate, collecting intraoperative CT data, inversely solving the temperature field based on the temperature calibration model established based on the CT value difference caused by the temperature change amount, superimposing the heat field in the form of key isothermal surface on the anatomical model and the navigation picture under the unified coordinate, and the heat field data can be fed back to the preoperative planning module to optimize the scheme.

[0027] Further, the working method of the tumor ablation integrated system based on the unified spatial coordinate framework further includes the following contents:

[0028] Step S5: Real-time data exchange between the preoperative planning module, the intraoperative navigation module and the intraoperative thermal field reconstruction module is realized by using the data interaction module to build a closed-loop control strategy and be used for the operator to dynamically adjust the treatment strategy according to the real-time temperature field; wherein the closed-loop control strategy includes that the intraoperative navigation module provides the needle tip coordinates and auxiliary thermal field positioning for the intraoperative thermal field reconstruction module, and the intraoperative thermal field reconstruction module provides the thermal field data for the preoperative planning module and feeds back to the preoperative planning module to optimize the scheme.

[0029] The application has the following advantages:

[0030] (1) The prediction accuracy of thermal ablation is significantly improved (verified by experiments)

[0031] In the in vitro experiment:

[0032] The long axis error of the simulated necrotic area is 6.0±3.2mm.

[0033] The short axis error of the simulation is 1.2±0.4mm.

[0034] It is shown that the constructed multi-physical field model has clinically acceptable prediction ability.

[0035] (2) The AR navigation puncture precision reaches millimeter level.

[0036] In the abdominal puncture phantom experiment: the needle tip positioning error is 1.62±0.43mm

[0037] The path deviation angle is 1.39±0.52°.

[0038] It is significantly better than the precision of the operator's experience operation.

[0039] (3) Intraoperative thermal field reconstruction is highly consistent with the actual necrotic area

[0040] The in vitro CT temperature measurement experiment shows that:

[0041] The long axis error of the 60℃ isothermal surface and the actual necrotic area is 5.2±2.8mm

[0042] The short axis error is 2.2±1.3mm

[0043] It can be directly used for intraoperative thermal dose evaluation.

[0044] (4) Comprehensive visualization: dual-dimension fusion of geometric domain + energy domain

[0045] The application realizes: preoperative temperature field prediction; intraoperative geometric navigation; intraoperative thermal field visualization; three-dimensional real-time superposition in the same coordinate; and realizes the full-process transparency from "where the needle pierces" to "how big it burns".

[0046] (5) Form a "planning-guiding-verification" closed loop to improve safety

[0047] The system automatically identifies areas that are under-heated, assisting the surgeon in deciding whether to add energy, thereby improving the integrity of the treatment and reducing the risk of recurrence. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the system of the present invention.

[0049] Figure 2 This is a system overall flow and module composition framework diagram of the present invention.

[0050] Figure 3 This is a schematic diagram of the geometric shape of the liver tissue thermal ablation model of the present invention.

[0051] Figure 4 This is a microwave ablation temperature field distribution diagram of the present invention.

[0052] Figure 5 This is a distribution map of tissue damage field caused by microwave ablation according to the present invention.

[0053] Figure 6 This is a visual representation of the preoperative planning module of the present invention.

[0054] Figure 7 This invention relates to an intraoperative CT temperature measurement visualization plugin.

[0055] Figure 8 For the CT scan and 3D reconstruction of this invention, the coordinate points of artificial markers are read.

[0056] Figure 9 This is the three-dimensional model for preoperative planning of the present invention and the information it carries.

[0057] Figure 10 This is a comparison of the distribution of the microwave ablation necrotic zone and the simulated tissue damage field in this invention. Detailed Implementation

[0058] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0059] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0060] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting; as used herein, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise. Furthermore, it is to be understood that the term "comprising" and / or "including" used herein is meant to be inclusive and not exclusive.

[0061] As shown in Figures 1 to 10 The application provides a tumor ablation integrated system based on a unified spatial coordinate framework and a working method thereof, characterized in that the following contents are included:

[0062] The application provides a tumor ablation integrated system based on a unified spatial coordinate framework, characterized in that the following contents are included: a unified spatial coordinate construction module, a preoperative planning module, an intraoperative navigation module, an intraoperative thermal field reconstruction module and a data interaction module.

[0063] The unified spatial coordinate construction module is used to realize coordinate alignment between a preoperative simulation space, a CT image space, an AR navigation space and a patient anatomy space and to establish consistent coordinate mapping from the patient anatomy space to the preoperative simulation space to the intraoperative image space to the AR navigation space.

[0064] The preoperative planning module is used to realize preoperative needle arrangement planning for thermal ablation under a unified coordinate framework, wherein the preoperative needle arrangement planning for thermal ablation includes multi-physical field model construction by the preoperative planning module, temperature field and necrosis range prediction by the preoperative planning module and needle arrangement path planning by the preoperative planning module.

[0065] The intraoperative navigation module is used to realize geometric guidance of an intraoperative puncture needle tip path and to ensure that an actual puncture path is consistent with a preoperative planning path, including real-time needle tip tracking, real-time calculation and planning path deviation and provision of guidance correction information.

[0066] The intraoperative thermal field reconstruction module is used to perform real-time temperature inversion and three-dimensional thermal field visualization based on a CT image.

[0067] The data interaction module is used to realize real-time data exchange between the preoperative planning module, the intraoperative navigation module and the intraoperative thermal field reconstruction module, and is also used to realize the function of dynamically adjusting a treatment strategy according to a real-time temperature field by the tumor ablation integrated system.

[0068] Further, the uniform spatial coordinate construction module adopts a double calibration strategy, including constructing a world coordinate anchor point by using a DPGS marker and mapping a simulation model to a CT coordinate system by using CT native scale and rigid registration, finally establishing a consistent coordinate mapping from a patient anatomy space to a preoperative simulation space to an intraoperative image space to an AR navigation space and a corresponding relationship between spaces, and realizing fusion display of different data sources in a uniform space.

[0069] In an embodiment of the present application, the uniform spatial coordinate construction module further comprises the following content:

[0070] The uniform spatial coordinate construction module is used to realize coordinate alignment between a preoperative simulation space, a CT image space, an AR navigation space and a patient anatomy space.

[0071] The present application adopts a double calibration strategy:

[0072] A world coordinate anchor point is constructed by using a DPGS marker;

[0073] A simulation model is mapped to a CT coordinate system by using CT DICOM native scale and rigid registration.

[0074] Finally, a one-to-one correspondence relationship of "patient anatomy space-preoperative simulation space-intraoperative CT space-AR navigation space" is established, and fusion display of different data sources in a uniform space is realized.

[0075] Further, a preoperative planning module is used to construct a multi-physical field model, including establishing a coupled model based on electromagnetic field distribution, biological heat conduction and tissue heat damage process; and using specific absorption rate as an electromagnetic energy deposition exogenous term to tightly couple electromagnetic field and heat field.

[0076] Further, a preoperative planning module is used to predict a temperature field and a necrosis range, including establishing a high-precision simulation model of tissue around an ablation needle by using temperature-dependent thermal physical parameters; wherein the temperature-dependent thermal physical parameters include a three-dimensional temperature field evolution sequence, a damage integral distribution at different time points, an equivalent surface corresponding to a necrosis threshold, a three-dimensional morphology of an ablation boundary and a safety boundary coverage condition.

[0077] Further, a preoperative planning module is used to plan a needle arrangement path, including registering and superimposing a simulation result and a patient CT anatomy model in a three-dimensional software, automatically generating a recommended puncture path on the basis of complete coverage of a tumor by a puncture path and reservation of a 5mm safety boundary by a puncture path; and outputting needle point coordinates, needle path direction vectors, puncture depth, ablation time and power suggestions.

[0078] In an embodiment of the present application, the meaning of reserving a 5mm safety margin is that the necrosis margin is required to exceed the tumor margin by at least 5mm in space, on the premise that the necrosis region completely envelopes the tumor target region.

[0079] In an embodiment of the present application, the preoperative planning module is used to realize preoperative needle arrangement planning of thermal ablation in a unified coordinate frame, including the following contents:

[0080] The preoperative planning module includes multi-physical field model construction, and the related contents are as follows:

[0081] This module establishes a coupled model based on the following three physical processes:

[0082] 1. Electromagnetic field distribution (Maxwell equations)

[0083] 2. Biological heat conduction (Pennes biological heat conduction equation)

[0084] 3. Tissue thermal injury (Arrhenius damage integral model)

[0085] And SAR (specific absorption rate) is used as an electromagnetic energy deposition exogenous term to tightly couple the electromagnetic field and the thermal field. The preoperative planning module includes temperature field and necrosis range prediction, and the related contents are as follows:

[0086] Temperature-dependent thermal physical parameters (thermal conductivity, specific heat capacity, electrical conductivity, dielectric constant, perfusion rate, etc.) are used to establish a high-precision simulation model for the tissue around the ablation needle.

[0087] Through transient solution, the following results are obtained:

[0088] Three-dimensional temperature field evolution sequence;

[0089] Damage integral distribution at different time points;

[0090] Necrosis threshold (Ω = 1) corresponding to the isosurface;

[0091] Ablation boundary three-dimensional morphology and safety margin coverage.

[0092] The preoperative planning module includes needle arrangement path planning, and the related contents are as follows:

[0093] The simulation results are registered and superimposed with the patient's CT anatomic model in 3D Slicer, and the recommended puncture path is automatically generated according to the "complete coverage of the tumor + 5mm safety margin" principle, and the following outputs are obtained:

[0094] Needle entry point coordinates;

[0095] Needle path direction vector;

[0096] Puncture depth

[0097] Ablation time / power suggestion.

[0098] In an embodiment of the present application, the meaning of reserving a safety margin of +5mm is that the necrosis boundary is required to exceed the tumor boundary by at least 5mm in space, on the premise that the necrosis region completely envelopes the tumor target region; wherein the necrosis region is a 60℃ isotherm, and the tumor target region is a region with coverage >100%.

[0099] In an embodiment of the present application, the system calculates the corresponding necrosis region by inputting microwave ablation parameters (power, time, needle type) as boundary conditions, using a multi-physical field model, so as to determine whether the above-mentioned "coverage" and "safety margin" requirements are met. In the system, dynamic adjustment is supported according to the simulation results, and in the verification experiment, the commonly used ablation time / power 50W / 300s of the operator is used as a reference parameter for effectiveness verification.

[0100] In an embodiment of the present application, the preoperative planning module includes the following contents:

[0101] The preoperative planning module includes multi-physical field model construction, temperature field and necrosis range prediction using the preoperative planning module, and needle arrangement path planning using the preoperative planning module.

[0102] The preoperative multi-physical field coupling simulation algorithm (electromagnetic→SAR→heat conduction→Arrhenius damage)

[0103] The electromagnetic power deposition in a local volume can be written as:

[0104]

[0105] where ε is the relative permittivity, σ is the conductivity, and ω is the angular frequency. r

[0106] Further, the specific absorption rate is used to represent the power density absorbed by unit mass of tissue:

[0107]

[0108] where ρ is the tissue density.

[0109] The spatial distribution of the specific absorption rate directly determines the local heating region and the temperature rise rate, and is coupled into the heat conduction equation as an external source term, forming an energy transfer bridge from the electromagnetic field to the thermal field. The evolution of the temperature in the tissue with time and space is described by the Pennes bio-heat conduction equation:

[0110]

[0111] ​where c is the specific heat capacity of tissue, k is the thermal conductivity of tissue, ω b is the blood perfusion rate, c b is the specific heat capacity of blood, T b is the arterial blood temperature, Q m is the metabolic heat source term. In the model, the surface of the ablation needle is considered as an adiabatic boundary, and the outer edge of the distal tissue is fixed at body temperature 37℃ to approximate the human core temperature environment. Through the above settings, the spatiotemporal distribution of the temperature field in the tissue can be obtained under the given microwave power and action time, as shown in Figure 3 .

[0112] On the basis of the temperature field, the irreversible damage of the tissue under high temperature is further quantitatively described by using the Arrhenius damage integral. The thermal damage degree Ω(t) of the local tissue can be expressed as

[0113]

[0114] where A is the frequency factor, E a is the activation energy, R is the gas constant, and T(τ) is the instantaneous temperature. It is generally believed that about 63% of cells will irreversibly die when Ω=1, and the necrosis fraction can be further defined as:

[0115] θ d =1-e -Ω

[0116] to depict the thermal damage degree accumulated with time at different spatial positions. By setting a threshold, the corresponding necrosis region isosurface can be extracted to estimate the final ablation range and safety boundary.

[0117] Further, the intraoperative navigation module is composed of an industrial camera, a visual marker, and a rendering workstation; the intraoperative navigation module calculates and plans the deviation of the needle tip feature point position in the camera coordinate system in real time, wherein the deviation from the planned path includes the three-dimensional position error of the needle tip and the path direction deviation angle; when the needle tip position deviates from the threshold, the intraoperative navigation module provides guiding and correcting information.

[0118] In an embodiment of the present application, the intraoperative navigation module is used to realize the geometric guidance of the intraoperative puncture needle tip path, and to ensure that the actual puncture path fits the preoperative planned path, which includes the following contents:

[0119] The intraoperative navigation module includes the construction of an AR guiding system, and the related contents are as follows:

[0120] The system is composed of an industrial camera, a visual marker (DPGS), and a rendering workstation, and realizes virtual-real superposition through the following steps:

[0121] Image acquisition;

[0122] DPGS marker recognition;

[0123] Camera pose inversion;

[0124] Projection matrix construction;

[0125] Preoperative planning model projection to video stream;

[0126] Virtual-real fusion rendering (semi-transparent body rendering, multi-view switching).

[0127] The intraoperative navigation module includes real-time needle tip tracking, and the relevant content is as follows:

[0128] According to the position of the needle tip feature point in the camera coordinate system, the deviation from the planned path is calculated in real time, including:

[0129] Three-dimensional position error of the needle tip;

[0130] Path direction deviation angle.

[0131] Further, the intraoperative thermal field reconstruction module performs real-time temperature inversion and three-dimensional thermal field visualization based on CT images, including temperature calibration model construction, intraoperative temperature inversion, and intelligent interpretation of thermal dose.

[0132] The temperature calibration model construction includes establishing a linear mapping relationship between the CT value difference caused by the temperature change and the temperature through the multi-temperature point experiment of the ex vivo sample.

[0133] The intraoperative temperature inversion includes collecting CT volume data at the key moment of ablation, performing CT value reading, temperature inversion, three-dimensional interpolation and Gaussian filtering, isothermic surface extraction, and superimposed display with the anatomical model and the planned path for each voxel.

[0134] The intelligent interpretation of thermal dose includes the intraoperative thermal field reconstruction module automatically calculating the distance between the 60℃ isothermic surface and the tumor boundary, the thermal dose coverage area, the under-burning area alarm, and determining whether additional ablation energy is needed.

[0135] In an embodiment of the present application, the intraoperative thermal field reconstruction module includes the following content:

[0136] When the deviation threshold is exceeded, the system provides guidance correction information.

[0137] In an embodiment of the present application, the intraoperative thermal field reconstruction module is used for real-time temperature inversion and three-dimensional thermal field visualization based on CT images, including the following content:

[0138] The intraoperative thermal field reconstruction module includes HU-temperature calibration model construction, and the relevant content is as follows:

[0139] Through the multi-temperature point experiment of the ex vivo pig liver, a linear mapping relationship between HU and temperature is established:

[0140] T = k * HU + b

[0141] where k is the temperature sensitivity coefficient, and b is the baseline correction term.

[0142] The intraoperative thermal field reconstruction module includes intraoperative temperature inversion, the relevant content is as follows:

[0143] CT volume data is collected at the key moment of ablation, and the following is performed for each voxel:

[0144] CT value reading;

[0145] Temperature inversion;

[0146] Three-dimensional interpolation and Gaussian filtering;

[0147] Isothermal surface extraction;

[0148] Superimposed display with anatomical model and planning path.

[0149] The intraoperative thermal field reconstruction module includes thermal dose intelligent interpretation, the relevant content is as follows:

[0150] The system automatically calculates:

[0151] Distance of 60℃ isothermal surface from tumor boundary;

[0152] Thermal dose coverage area;

[0153] Under-burning area alarm;

[0154] Whether additional ablation energy is needed.

[0155] In an embodiment of the present application, the system mainly supports decision assistance, that is, the doctor re-runs the simulation or increases the ablation time (for example, adds 60s or 1000J energy) according to the size of the residual area visualized. If the automatic calculation of the additional value has not been realized, the current version highlights the under-heated area to prompt the operator to adjust the needle position or extend the ablation time in that direction. Future work will introduce an energy automatic compensation algorithm based on inverse optimization.

[0156] In an embodiment of the present application, the intraoperative thermal field reconstruction module performs real-time temperature inversion and three-dimensional thermal field visualization based on CT images, including temperature calibration model construction, intraoperative temperature inversion, and thermal dose intelligent interpretation, including the following contents:

[0157] Wherein the navigation hand needle tip positioning and deviation calculation includes the following contents:

[0158] Let the planning needle path be a straight line Lp (represented by point Po and direction vector Vp), and the actual needle tip projection be point Pa.

[0159] Distance deviation (shortest distance from point to straight line):

[0160]

[0161] Angular deviation (needle vector vs. planned vector) :

[0162]

[0163] Where intraoperative thermal field reconstruction includes the following:

[0164] At the mechanism level, the X-ray linear attenuation coefficient of biological soft tissue changes measurably with temperature rise, which is reflected in the CT image as a systematic shift in Hounsfield units. In the clinically relevant range of 30-100°C, this relationship can be locally approximated as a monotonically decreasing linear function, so a first-order linear model can be used to describe the coupling between temperature and CT value:

[0165] T = kAHU + b

[0166] k < 0

[0167] Where AHU is the CT value difference caused by temperature change, T is the corresponding temperature change, and k and b are the linear regression coefficients obtained by experimental calibration.

[0168] Where intraoperative decision support, coverage / under-burn assessment indicators (decision rules) include the following:

[0169] Volume coverage (Coverage) :

[0170]

[0171] Where Vtumor represents: the tumor target volume based on preoperative or intraoperative image segmentation reconstruction.

[0172] V ≥ 60°C represents: the effective ablation necrosis volume generated by simulation prediction or intraoperative temperature measurement inversion.

[0173] ∩ represents: set intersection operation, representing the overlapping part of the tumor volume and the necrosis volume in three-dimensional space.

[0174] Dice coefficient (predicted necrosis vs. actual necrosis) :

[0175]

[0176] Where A represents: the predicted necrosis area volume

[0177] B represents: the actual necrosis area volume

[0178] A∩B represents: the overlapping volume of the predicted area and the actual area in space.

[0179] |A| and |B| are the total volume of each of the two, respectively.

[0180] Further, the data interaction module realizes data exchange between the preoperative planning module, the intraoperative navigation module, and the intraoperative thermal field reconstruction module, including establishing a complete data closed loop, wherein establishing the complete data closed loop includes that the preoperative planning module provides a needle path model for the intraoperative navigation module, the intraoperative navigation module provides a needle tip coordinate and auxiliary thermal field positioning for the intraoperative thermal field reconstruction module, and the intraoperative thermal field reconstruction module provides a thermal dose result for the preoperative planning module and feeds back to the next puncture scheme optimization.

[0181] According to a second aspect of the present application, the present application provides a working method of a tumor ablation integrated system based on a unified spatial coordinate framework, which adopts the tumor ablation integrated system based on the unified spatial coordinate framework according to any one of the present application, and is characterized in that the working method of the tumor ablation integrated system based on the unified spatial coordinate framework comprises the following contents:

[0182] Step S1: using the unified spatial coordinate construction module, fixing the DPGS marker in the surgical area, extracting the marker coordinate as a reference through the CT image, and then mapping the preoperative simulation model, the anatomical model, the intraoperative image, and the AR navigation space to the reference coordinate through rigid registration, to ensure multi-dimensional space alignment;

[0183] Step S2: using the preoperative planning module, importing the CT image of the patient to reconstruct the tumor anatomical model under the unified coordinate, combining physical field simulation to predict the ablation range, and designing and outputting the puncture planning path to the unified coordinate framework on the basis of completely covering the tumor in the puncture path and reserving a 5mm safety boundary in the puncture path;

[0184] Step S3: using the intraoperative navigation module, capturing the DPGS marker through an industrial camera under the unified coordinate, inversely solving the camera pose, superimposing the preoperative planning path and the tumor model on the surgical scene in the form of AR, and real-time guiding the puncture operation;

[0185] Step S4: using the intraoperative thermal field reconstruction module; under the unified coordinate, collecting intraoperative CT data, and inversely solving the temperature field based on the temperature calibration model established based on the CT value difference caused by the temperature change amount, superimposing the thermal field in the form of key isothermal surface on the anatomical model and the navigation picture under the unified coordinate, and the thermal field data can be fed back to the preoperative planning module to optimize the scheme.

[0186] Further, the working method of the tumor ablation integrated system based on the unified spatial coordinate framework further comprises the following contents:

[0187] Step S5: Real-time data exchange between the preoperative planning module, intraoperative navigation module and intraoperative thermal field reconstruction module is realized by using the data interaction module to build a closed-loop control strategy and use it to adjust the treatment strategy dynamically according to the real-time temperature field; wherein the closed-loop control strategy includes that the intraoperative navigation module provides the needle tip coordinates and auxiliary thermal field positioning for the intraoperative thermal field reconstruction module, and the intraoperative thermal field reconstruction module provides the thermal field data for the preoperative planning module and feeds back to the preoperative planning module to optimize the scheme.

[0188] In addition to the above, the present application also has related embodiments, including the following:

[0189] As Figure 1 shown, the present application proposes a tumor microwave ablation preoperative planning, intraoperative navigation and thermal field visualization system based on a unified spatial coordinate framework, mainly including the following three functional modules: preoperative planning module; intraoperative navigation module; intraoperative thermal field visualization module. The above three modules realize coordinate registration and data flow intercommunication under the unified spatial coordinate framework, and constitute a closed-loop workflow of "planning-navigation-verification".

[0190] The overall operation process of the system is as follows:

[0191] First, multi-modal medical image data acquisition and three-dimensional reconstruction are carried out in the preoperative stage to establish a patient-specific anatomical model; then, finite element multi-physical field simulation is used to predict the temperature field and necrosis range under different power parameters, and individualized needle placement planning is completed; in the intraoperative stage, the needle tip path guidance and real-time positioning are realized through the augmented reality navigation device; CT images are collected at the key moment of ablation, the three-dimensional temperature field is reconstructed through the HU-temperature calibration relationship, and the thermal field is superimposed with the preoperative model and navigation path to display, thereby realizing the intuitive presentation and boundary interpretation of the intraoperative thermal dose distribution.

[0192] The preoperative planning module is realized based on a finite element multi-physical field model. CT image data of a patient or a phantom is acquired first, and a three-dimensional geometric model of a tumor, blood vessels and adjacent important tissues is reconstructed by threshold segmentation and region growing with the help of a medical image processing software such as 3D Slicer. Then the model is imported into a COMSOL Multiphysics platform to establish an electromagnetic field model based on Maxwell's equations, a heat conduction field model based on the Pennes bioheat conduction equation and a tissue perfusion heat dissipation model. The necrosis range is calculated by Arrhenius damage integral. Then the specific absorption rate (SAR) is taken as an exogenous term to input the heat conduction equation, and the temperature field distribution and its time evolution curve in the tissue are obtained by transient solution. Then the isosurface corresponding to the damage integral Ω = 1 is taken as the necrosis threshold to extract the coagulation necrosis area and superimpose it with the tumor boundary. The optimal needle position and approach angle are automatically recommended according to the standard of "tumor completely covered and exceeding the 5mm safety boundary". Finally, the predicted temperature field and necrosis area are exported in DICOM format and rigidly registered with the CT model to ensure the unification of the energy domain and the geometric domain, and finally the ablation range, temperature distribution and safety boundary are quantitatively predicted to provide a path basis for intraoperative navigation.

[0193] The intraoperative navigation module realizes real-time guidance of the needle tip path by augmented reality (AR) technology, which is composed of an industrial camera, a visual marker, a navigation workstation and a display device. The visual marker (DPGS Marker) is used as the world coordinate anchor point, the camera external parameters are calculated by camera calibration and pose estimation algorithm, the unified mapping of camera coordinates, model coordinates and actual surgical space is realized, then the needle path model planned preoperatively is imported into the AR navigation system, the workstation renders the virtual path to the video screen frame by frame, achieving the spatial overlap of the needle path and the patient entity. The spatial position of the needle tip is calculated by the change of the camera field of view, achieving millimeter-level positioning accuracy and real-time feedback of the deviation angle of the needle tip and the planned path. The semi-transparent body rendering and multi-view switching interactive visualization method is also used to facilitate the operator to adjust the transparency of the virtual information display to intuitively judge the position of the needle tip and the approach angle.

[0194] This module is used to realize three-dimensional heat field reconstruction and visualization based on CT temperature measurement. First, the CT images at different temperatures are collected through the multi-temperature point experiment of the ex vivo tissue, and the quantitative relationship between temperature and CT value is established by linear regression after removing abnormal voxels as follows:

[0195] T = kAHU + b

[0196] where k is the temperature sensitivity coefficient, b is the baseline correction parameter (where ), and CT scanning is performed at key ablation time points to obtain three-dimensional data containing the needle path and surrounding tissue, then the CT voxel grayscale is mapped to a temperature matrix, combined with three-dimensional Gaussian filtering and volume rendering technology to reconstruct the continuous heat field distribution, and then the heat field model is superimposed with the anatomical model and needle path in a unified coordinate frame to display the temperature gradient and isothermal surface in pseudo-color for the operator to evaluate the heat dose coverage range in real time, while the system automatically calculates the distance between the 60℃ isothermal surface of the heat field and the tumor boundary, and prompts and suggests additional energy output when the distance does not reach the 5mm safety threshold, realizing intelligent decision support during the operation.

[0197] Through the above modular design, the system realizes closed-loop control of preoperative prediction, intraoperative guidance and intraoperative verification.

[0198] Integrated visualization of thermal energy field and anatomical space; real-time interpretation and intelligent feedback of ablation safety boundary. Compared with traditional image navigation or single heat monitoring technology, the present application realizes the fusion of geometric domain and energy domain in a unified spatial coordinate frame, significantly improving the operation accuracy, heat dose control reliability and intraoperative information transparency of tumor microwave ablation. Through ex vivo pig liver experiment verification, the intraoperative navigation needle tip positioning error of the system is 1.62±0.43mm, and the path deviation angle is 1.39±0.52°.

[0199] The 60℃ isothermal surface of the intraoperative heat field reconstruction and the actual necrotic area long axis and short axis error are 5.2±2.8mm and 2.2±1.3mm respectively.

[0200] The experimental results show that the system of the present application has reached the clinically acceptable range in terms of geometric accuracy and heat field reconstruction accuracy.

[0201] In an embodiment of the present application, the experimental results include the following contents:

[0202] (1) The heat ablation prediction accuracy is significantly improved (experimental verification)

[0203] In the ex vivo experiment:

[0204] The long axis error of the simulated predicted necrotic area is 1mm

[0205] The short axis error of the simulation is 0.5mm

[0206] It is shown that the constructed multi-physical field model has clinically acceptable prediction ability.

[0207] (2) The AR navigation puncture accuracy reaches millimeter level

[0208] In the abdominal puncture phantom experiment: needle tip positioning error: 1.62±0.43mm

[0209] Path deviation angle: 1.39 ± 0.52°

[0210] Significantly better than the accuracy of the surgeon's experience operation.

[0211] (3) Intraoperative thermal field reconstruction is highly consistent with the actual necrotic area

[0212] Ex vivo CT temperature measurement experiments show that:

[0213] 60℃ isothermal surface and actual necrotic area long axis error: 5.2 ± 2.8mm

[0214] Short axis error: 2.2 ± 1.3mm

[0215] Can be directly used for intraoperative thermal dose evaluation.

[0216] (4) Comprehensive visualization: geometric domain + energy domain dual-dimension fusion

[0217] The present application realizes: preoperative temperature field prediction; intraoperative geometric navigation; intraoperative thermal field visualization; three-dimensional real-time superposition in the same coordinate; realizes the whole process transparency from "where the needle pierces" to "how big it burns".

[0218] (5) Form a "planning-guiding-verification" closed loop to improve safety

[0219] The system automatically prompts the under-burning area, assists the surgeon in deciding whether to add energy, improves the treatment integrity, and reduces the risk of recurrence.

[0220] In an embodiment of the present application, Figure 2 The whole process closed-loop working mechanism of the system from preoperative planning, intraoperative navigation to intraoperative thermal monitoring is shown. As shown in the figure, the system integrates CT image data, COMSOL simulation model, augmented reality navigation and real-time thermal field feedback through a unified coordinate framework, realizing seamless flow and interaction of data at each stage.

[0221] In an embodiment of the present application, Figure 3 The axisymmetric geometric structure of the microwave ablation needle and the tissue around it for finite element simulation is shown. The model sequentially constructs the inner conductor, dielectric, outer conductor (catheter) and liver tissue layer from inside to outside, clearly defines the size and material properties of each physical component, and provides accurate geometric boundaries for electromagnetic field and thermal field coupling calculation.

[0222] In an embodiment of the present application, Figure 4 The three-dimensional simulation result of the transient temperature field calculated based on the multi-physical field coupling model is shown. The temperature distribution of the tissue around the ablation needle is intuitively reflected by the color gradient in the figure, and the high temperature area in the center decreases in an ellipsoidal shape to the four corners, verifying the heat conduction law in biological tissues.

[0223] In an embodiment of the present application, Figure 5 The cloud atlas of tissue necrosis fraction distribution calculated based on Arrhenius damage integral model is shown. The deep red area represents the irreversible coagulation necrosis range where the damage integral reaches the necrosis threshold (Ω = 1), which can be used to estimate whether the ablation boundary can completely cover the tumor before operation.

[0224] In an embodiment of the present application, Figure 6 The interactive interface of the preoperative planning module in the three-dimensional visualization software is presented. The planned virtual needle path and the predicted necrosis zone thermal field (yellow / red area) are superimposed on the CT slices of the patient, which intuitively shows the spatial coverage relationship between the estimated ablation range and the tumor target area and the safety margin.

[0225] In an embodiment of the present application, Figure 7 The intraoperative thermal field visualization effect based on real-time inversion of CT values is shown. The system superimposes the calculated temperature matrix on the CT tomographic image in the form of pseudo-color thermal map, clearly outlining the thermal dose distribution of the current ablation plane, especially the actual range of action of the 60℃ isotherm.

[0226] In an embodiment of the present application, Figure 8 The recognition and positioning process of artificial markers (DPGS markers) in CT image processing is shown. The crosshair in the figure accurately captures the center coordinates of the surface marker points, and these feature points are used as reference anchor points of the unified coordinate system to realize preoperative simulation, intraoperative navigation and rigid registration of the CT image space.

[0227] In an embodiment of the present application, Figure 9 A three-dimensional digital model diagram containing planning information generated by the system is shown. The reconstructed lesion model, surface marker array and planned optimal puncture path vector (including needle entry point and direction) are clearly marked in the figure, providing standardized geometric reference data for intraoperative navigation and guidance.

[0228] In an embodiment of the present application, Figure 10 The comparison and analysis of the actual necrosis zone of the experimental porcine liver section and the simulation prediction result are shown. The gray-white coagulation necrosis area in the left photo is highly consistent with the shape and size of the simulation cloud atlas on the right, which proves the effectiveness of the system's multi-physical field model in predicting the ablation boundary.

[0229] The above is the preferred embodiment of the present application, any changes made according to the technical solutions of the present application, as long as the generated function does not exceed the scope of the technical solutions of the present application, all belong to the protection scope of the present application.

Claims

1. A tumor ablation integrated system based on a unified spatial coordinate frame, characterized in that, It includes a unified spatial coordinate construction module, a preoperative planning module, an intraoperative navigation module, an intraoperative thermal field reconstruction module, and a data interaction module; The unified spatial coordinate construction module is used to achieve coordinate alignment between the preoperative simulation space, CT image space, AR navigation space and patient anatomical space and to establish a consistent coordinate mapping from patient anatomical space to preoperative simulation space to intraoperative image space to AR navigation space. The preoperative planning module is used to realize preoperative needle placement planning for thermal ablation under a unified coordinate framework. The preoperative needle placement planning for thermal ablation includes using the preoperative planning module to construct a multiphysics model, using the preoperative planning module to predict the temperature field and necrosis range, and using the preoperative planning module to plan the needle placement path. The intraoperative navigation module is used to achieve geometric guidance of the intraoperative puncture needle tip path and ensure that the actual puncture path conforms to the preoperative planned path, including real-time needle tip tracking, real-time calculation of deviation from the planned path and provision of guidance and correction information; The intraoperative thermal field reconstruction module is used for real-time temperature inversion and three-dimensional thermal field visualization based on CT images. The data interaction module is used to realize real-time data exchange between the preoperative planning module, the intraoperative navigation module, and the intraoperative thermal field reconstruction module, and at the same time, it is used to realize the function of the integrated tumor ablation system to dynamically adjust the treatment strategy according to the real-time temperature field.

2. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The unified spatial coordinate construction module adopts a dual calibration strategy, including using DPGS markers to construct world coordinate anchor points and using the CT native scale and rigid registration to map the simulation model to the CT coordinate system. Finally, it establishes a consistent coordinate mapping from the patient's anatomical space to the preoperative simulation space to the intraoperative image space to the AR navigation space and the correspondence between each space, so as to realize the fusion display of different data sources in a unified space.

3. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The preoperative planning module was used to construct a multiphysics model, including establishing a coupled model based on electromagnetic field distribution, biological heat conduction and tissue thermal damage process; and specific absorption rate was used as the external source term for electromagnetic energy deposition to tightly couple the electromagnetic field and the thermal field.

4. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The preoperative planning module is used to predict the temperature field and necrosis range, including the establishment of a high-precision simulation model of the tissue around the ablation needle using temperature-dependent thermophysical parameters. The temperature-dependent thermophysical parameters include the three-dimensional temperature field evolution sequence, the damage integral distribution at different time points, the isosurface corresponding to the necrosis threshold, the three-dimensional morphology of the ablation boundary, and the coverage of the safety boundary.

5. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The preoperative planning module is used for needle placement path planning, which includes registering and overlaying the simulation results with the patient's CT anatomical model in 3D software. Based on the complete coverage of the tumor by the puncture path and the reservation of a safety boundary of +5mm for the puncture path, a recommended puncture path is automatically generated. The module also outputs the coordinates of the needle insertion point, the direction vector of the needle path, the puncture depth, the ablation time, and the power suggestion.

6. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The intraoperative navigation module consists of an industrial camera, visual markers, and a rendering workstation. Based on the position of the needle tip feature point in the camera coordinate system, the intraoperative navigation module calculates the deviation from the planned path in real time. The deviation from the planned path includes the three-dimensional position error of the needle tip and the path direction deviation angle. When the needle tip position deviates from the threshold, the intraoperative navigation module provides guidance and correction information.

7. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The intraoperative thermal field reconstruction module performs real-time temperature inversion and three-dimensional thermal field visualization based on CT images, including temperature calibration model construction, intraoperative temperature inversion, and intelligent interpretation of thermal dose. The temperature calibration model construction includes establishing a linear mapping relationship between the difference in CT values ​​caused by temperature changes and temperature through multi-temperature point experiments on ex vivo samples; Intraoperative temperature inversion includes acquiring CT volume data at critical moments of ablation, performing CT value reading, temperature inversion, three-dimensional interpolation and Gaussian filtering, isothermal surface extraction, and overlay display with anatomical model and planned path for each voxel; The intelligent thermal dose interpretation includes an intraoperative thermal field reconstruction module that automatically calculates the distance between the 60°C isothermal surface and the tumor boundary, the thermal dose coverage area, and alarms for under-burned areas, and determines whether additional ablation energy is needed.

8. The integrated tumor ablation system based on a unified spatial coordinate frame according to claim 1, characterized in that, The data interaction module enables data exchange between the preoperative planning module, the intraoperative navigation module, and the intraoperative thermal field reconstruction module, including establishing a complete data loop. This complete data loop includes the preoperative planning module providing a needle path model to the intraoperative navigation module, the intraoperative navigation module providing needle tip coordinates and auxiliary thermal field positioning to the intraoperative thermal field reconstruction module, and the intraoperative thermal field reconstruction module providing thermal dosage results to the preoperative planning module and feeding back into the optimization of the next puncture plan.

9. A method for operating an integrated tumor ablation system based on a unified spatial coordinate frame, applied in any one of claims 1 to 8, characterized in that, The working method of the integrated tumor ablation system based on a unified spatial coordinate frame includes the following: Step S1: Using a unified spatial coordinate construction module, the DPGS markers are fixed in the surgical area. The marker coordinates are extracted from CT images as a reference. Then, through rigid registration, the preoperative simulation model, anatomical model, intraoperative images, and AR navigation space are all mapped to the reference coordinates to ensure multi-dimensional spatial alignment. Step S2: Using the preoperative planning module, import the patient's CT images to reconstruct the tumor anatomy model under a unified coordinate system, combine physical field simulation to predict the ablation range, and design and output the puncture planning path to the unified coordinate frame based on the complete coverage of the tumor by the puncture path and the +5mm safety boundary reserved by the puncture path. Step S3: Using an intraoperative navigation module, under a unified coordinate system, DPGS markers are captured by an industrial camera, the camera pose is solved in reverse, and the preoperative planned path and tumor model are superimposed on the surgical scene in AR form to guide the puncture operation in real time. Step S4: Use the intraoperative thermal field reconstruction module; under a unified coordinate system, collect intraoperative CT data, invert the temperature field based on the temperature calibration model established by the CT value difference caused by temperature change, and superimpose the thermal field as a key isothermal surface onto the anatomical model and navigation screen under the unified coordinate system. The thermal field data can be fed back to the preoperative planning module to optimize the scheme.

10. The working method of the integrated tumor ablation system based on a unified spatial coordinate frame according to claim 9, characterized in that, The working method of the integrated tumor ablation system based on a unified spatial coordinate frame also includes the following: Step S5: A data interaction module is used to realize real-time data exchange between the preoperative planning module, the intraoperative navigation module, and the intraoperative thermal field reconstruction module, and to construct a closed-loop control strategy for the operator to dynamically adjust the treatment strategy based on the real-time temperature field. The closed-loop control strategy includes the intraoperative navigation module providing needle tip coordinates and auxiliary thermal field positioning to the intraoperative thermal field reconstruction module, and the intraoperative thermal field reconstruction module providing thermal field data to the preoperative planning module and feeding it back to the preoperative planning module to optimize the plan.

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