CN115153829A - Electric pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction - Google Patents
Electric pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction Download PDFInfo
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Abstract
The invention relates to an electric pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction, which comprises the steps of firstly constructing an organ tissue ablation model with group characteristics according to patient case information characteristics; on the basis, ablation electrode needle distribution is carried out on an ablation area of a patient, impedance measurement data among needle distribution electrode groups are obtained through an impedance measurement feedback module, and in-vivo tissue dielectric characteristic parameter solving is carried out; and carrying out non-uniform reconstruction on the tissue dielectric parameters between the ablation electrodes in the group characteristic model by using the obtained in-vivo tissue dielectric characteristic parameters to form an individual ablation optimization model with the in-vivo tissue dielectric characteristics of the patient, and simultaneously correcting the parameters of the ablation electric pulses output by the high-voltage pulse source based on the optimization model. According to the method, the dielectric parameters of tissues in the ablation area in the ablation model are non-uniformly reconstructed according to the dielectric characteristics of the tissues of the patient, the method has individual characteristics, the model precision is high, and the method is favorable for establishing an accurate preoperative surgical planning scheme.
Description
Technical Field
The invention relates to the technical field of medical instruments, in particular to an electric pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction.
Background
The irreversible tumor electroporation ablation technology is a mechanism that a high-voltage ultrashort pulse electric field with pulse width microsecond level and field intensity of several kilovolts per centimeter can cause irreversible damage to cell membranes, realizes tumor cell killing, and is a novel physical tumor ablation technology appearing in recent years. The technology has no thermal injury in the treatment process, has obviously lower injury to blood vessels, nerves and extracellular matrix than tumor cells, and has been used for minimally invasive treatment of various tumors along with the deep research and the continuous development of the clinical application of the current high-voltage electric pulse ablation technology.
The high-voltage electric pulse ablation technology has wide clinical application prospect, but still has certain defects in clinical application: that is, in the clinical application of current irreversible electroporation tumor ablation therapy, the treatment dosage (pulse parameters, duration, etc.) is generally judged by a doctor by experience, and excessive treatment (damage to normal tissues) or under treatment (incomplete ablation) is easy to occur. The main reason for this situation is that the current irreversible electroporation tumor ablation treatment technology has an incomplete preoperative planning scheme for personalized treatment, i.e. the ablation model is not accurate enough. The essence of the electric pulse tumor ablation treatment is that a high-voltage pulse electric field acts on a tumor region, and the high-voltage electric field with certain field intensity causes irreversible damage to tumor cells, so that researchers at home and abroad can realize the simulation of an ablation process and an ablation effect by constructing a preoperative electric pulse ablation model of a patient so as to achieve an ideal ablation effect, and the electric pulse tumor ablation treatment has an active effect on the accuracy of the electric pulse tumor ablation treatment. One of the key elements of the electric pulse ablation preoperative model construction is the setting of tissue dielectric parameters and distribution characteristics thereof, the dielectric characteristic parameter data of organ tissues in the existing model mostly comes from literature reports (part of parameters come from inactivated tissue dielectric characteristic measurement data), and the uniform distribution parameter setting is mostly adopted on the dielectric characteristic parameter distribution of tumor tissues. However, the real distribution of the dielectric properties of the organ and tissue is that the organ and tissue usually have different dielectric property parameters due to different classifications, such as tumors with different properties in one organ, the dielectric properties of the tumor tissue are different, and the dielectric properties of different parts of the same tumor are also different. Therefore, the existing electric pulse ablation preoperative model cannot embody individual characteristics of nonuniform distribution of dielectric properties of organs and tissues of a patient, the simulation precision is not high enough in the application of electric pulse ablation preoperative planning, the electric pulse parameter output is not accurate enough, and therefore the modeling method of the electric pulse ablation preoperative model needs to be further optimized to improve the accuracy of electric pulse ablation preoperative planning.
Disclosure of Invention
Aiming at the technical problem that the simulation precision of an organ tissue ablation model is not high in planning application before electrical pulse ablation operation, the invention aims to provide an electrical pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction.
In order to realize the task, the invention adopts the following technical solution to realize:
the method for optimizing the precision of an electric pulse ablation model based on the inhomogeneous reconstruction of the impedance information of active tissues is characterized in that after a basic model with the group characteristics is constructed, the inhomogeneous reconstruction is further carried out on dielectric property parameters of tissues in an ablation area so as to obtain an optimized model, and the method specifically comprises the following steps:
firstly, extracting case information characteristics of a patient, constructing an organ electric pulse ablation basic model with population characteristics based on the characteristics, and obtaining an initial value of ablation electric pulse parameters and an ablation area electrode needle arrangement scheme;
step two, according to the electrode needle arrangement scheme of the ablation area, carrying out electrode needle arrangement in the ablation area, obtaining impedance measurement data among needle arrangement electrode groups through an impedance measurement feedback module, and solving dielectric characteristic parameters of in-vivo tissues;
and thirdly, performing non-uniform reconstruction of dielectric characteristic parameters on the organ electric pulse ablation basic model with the group characteristics established in the first step by using the dielectric characteristic parameter data of the patient in-vivo tissues to form an organ electric pulse ablation individualized model with the non-uniform distribution characteristics of the patient in-vivo tissue impedance. The ablation electrical pulse parameters are optimized based on the model pulse source.
According to the invention, the implementation method for extracting the case information characteristics of the patient and constructing the organ electric pulse ablation basic model with the population characteristics based on the case information characteristics to obtain the ablation electric pulse parameters and the ablation region electrode needle arrangement scheme comprises the following steps:
(1) Patient case information feature extraction
The extraction of the case information characteristics of the patient mainly comprises the following steps: imaging and histology information of ablated organs and pathological tumors;
(2) Three-dimensional reconstruction ablation organ morphology model
Based on the imaging data of the ablation organ of the patient, a three-dimensional model of the ablation organ is established by utilizing a three-dimensional reconstruction technology, and the model comprises a main tissue area of the organ.
The main tissue area of the ablation organ at least comprises a normal tissue area, a tumor tissue area and a tumor marginal tissue area;
(3) Assignment of dielectric property parameters to living biological tissues
According to the histological classification typing characteristics of the patient case ablated organs and the pathological tumors, assigning values to the ablated organ tissue morphological model by calling the data parameters of the active tissue dielectric characteristic database to form an organ electric pulse ablation basic model with the group characteristics;
the active tissue dielectric characteristic database consists of tissue dielectric characteristic parameters obtained by adopting an active tissue dielectric characteristic measuring method, and database data are continuously enriched along with the increase of the number of cases; the tissue dielectric characteristic parameters are statistical calculation results after multi-sample measurement, and reflect the population characteristics of tissues of different age groups and different classifications.
The dielectric characteristic parameters comprise dielectric characteristic parameters of normal tissue regions of organs, dielectric characteristic parameters of tissues of tumor regions and dielectric characteristic parameters of tissues of tumor marginal regions.
(4) Ablation electrode distribution parameter solution
Establishing an organ electric pulse ablation simulation based on an organ electric pulse ablation basic model according to an electric pulse ablation electric field setting principle and in combination with an electromagnetic field simulation analysis method, and forming an ablation electric pulse parameter initial value and an ablation area electrode needle arrangement scheme parameter according to the maximum tumor cross-sectional area and the ablation threshold parameter of tumor tissues; simultaneously, carrying out boundary marking on effective ablation electric field regions between the ablation electrodes;
the needle arrangement scheme parameter refers to the position information of the ablation electrode needle in a lesion area.
Specifically, the implementation method of performing electrode needle distribution in the ablation region of the organ of the patient according to the ablation region electrode needle distribution scheme in the step two, obtaining impedance measurement data between the needle distribution electrode pair through the impedance measurement feedback module, and performing in-vivo tissue dielectric characteristic parameter solution includes:
(1) In vivo measurement of tissue impedance between ablation electrode pairs
The impedance measurement feedback module adopts a multi-frequency current excitation-voltage measurement mode to measure the in-vivo electrical impedance of tissues between ablation electrode needles to obtain tissue electrical impedance parameters;
(2) Optimal solution for tissue dielectric characteristic parameters between ablation electrode needle groups
And (3) according to the in-vivo electrical impedance parameter data of the tissues among the ablation electrode needle groups, taking the effective ablation electric field region among the ablation electrode needle groups marked in the step one as a tissue dielectric characteristic parameter optimization region, and combining finite element simulation and an inverse problem optimization solving algorithm to obtain in-vivo dielectric characteristic parameters of the tissues among the ablation electrode needle groups.
Further, the third step of utilizing the dielectric characteristic parameter data of the patient in-vivo tissue to perform the dielectric characteristic parameter non-uniform reconstruction on the organ electric pulse ablation basic model with the population characteristic established in the first step, and the implementation method for forming the organ tissue electric pulse ablation individualized model with the impedance distribution characteristic of the patient in-vivo tissue is as follows:
(1) Carrying out non-uniform reconstruction of tissue dielectric characteristic parameters on the ablation region in the organ electric pulse ablation basic model established in the step one;
the tissue dielectric characteristic parameters are subjected to non-uniform reconstruction, namely the tissue dielectric characteristic parameters of the regions corresponding to the original model are replaced by the tissue in-vivo dielectric characteristic parameters of the electrode needle groups of the ablation regions of the patient, which are obtained in the step two, according to set rules;
(2) And optimizing the parameters of the ablation electric pulse based on the new model.
Compared with the prior art, the precision optimization method of the electric pulse ablation model based on the non-uniform reconstruction of the impedance information of the active tissue, provided by the invention, has the technical innovation that: tissue dielectric characteristic parameters in the model are obtained based on the in-vivo electrical impedance measurement data of active tissues in an ablation area of organ lesion of a patient, the tissue dielectric parameters in the ablation area of the model are non-uniformly distributed, individual characteristics are achieved, the model precision is high, optimal output of ablation electrical pulse parameters can be achieved, and an accurate preoperative surgical planning scheme can be established.
Drawings
FIG. 1 is a block diagram of the method for optimizing the precision of an electric pulse ablation model based on the non-uniform reconstruction of the impedance information of active tissues;
FIG. 2 is a flow chart of modeling an individualized organ ablation model;
FIG. 3 is three-dimensional modeling of organ tissue and division of tissue regions;
FIG. 4 is an ablation electrode needle distribution diagram;
FIG. 5 is a flow chart for solving dielectric parameters of in-vivo tissues among ablation needle groups;
FIG. 6 is a schematic diagram of the non-uniform reconstruction of tissue dielectric parameters between ablation needle groups in a model
The present invention will be described in further detail with reference to the following drawings and examples.
Detailed Description
As mentioned above, most of the existing electric pulse ablation preoperative models are uniformly distributed when setting the tissue dielectric property parameters of an ablation region, and the individualized characteristics of the real non-uniform distribution of the tissue dielectric property cannot be reflected, so that the problems of insufficient simulation precision, inaccurate ablation electric pulse parameter setting and the like exist in the application of electric pulse ablation preoperative planning. Therefore, the invention provides an electric pulse ablation model precision optimization method based on active tissue electrical impedance information non-uniform reconstruction. The method is characterized in that firstly, an organ tissue ablation basic model with group characteristics is constructed according to pathological change characteristics of a patient, further, nonuniform optimization reconstruction is carried out on tissue impedance distribution parameters of an inter-ablation electrode pair area in the basic model by using patient in-vivo tissue impedance measurement parameters, an individual organ tissue ablation model with in-vivo tissue impedance characteristic distribution is formed, ablation electric pulse parameters can be revised based on the optimization model, and the simulation precision of electric pulse ablation preoperative planning can be improved.
Referring to fig. 1, the present embodiment provides a precision optimization method for an electric pulse ablation model based on non-uniform reconstruction of active tissue electrical impedance information, which is implemented in the following three steps, and a flowchart is shown in fig. 2. Firstly, extracting case information characteristics of a patient, constructing an organ electric pulse ablation basic model with population characteristics based on the characteristics, and obtaining an initial value of ablation electric pulse parameters and an ablation area electrode needle arrangement scheme.
In this embodiment, taking a patient with prostate tumor as an example, a specific implementation method of the first step is described, which is specifically divided into the following implementation steps:
(1) Patient case information feature extraction
The extraction of the case information characteristics of the patient mainly comprises the following steps: ablation of imaging and histology information of organs and diseased tumors; this example is a prostate tumor patient whose imaging data is an MRI image of the patient, and the tumor is a malignant tumor.
(2) Three-dimensional reconstruction ablation organ morphology model
Based on the imaging data of the patient ablation organ, a three-dimensional model of the ablation organ is established by utilizing a three-dimensional reconstruction technology, wherein the model comprises a main tissue area of the organ, and the main tissue area at least comprises an organ normal tissue area, a tumor tissue area and a tumor marginal tissue area.
As shown in fig. 3, in the present embodiment, when performing morphological modeling of a prostate organ, image processing is first performed on an MRI sequence scan image of a prostate organ of a patient, and modeling of an organ solid model is realized by means of three-dimensional inverse CAD software geologic, three-dimensional CAD design software Solidworks, and the like. And performing region division on the organ according to the growth characteristics of the tumor mass, wherein the main tissue regions comprise a normal tissue region, a tumor edge tissue region and a tumor tissue region.
(3) And (3) according to the histological classification typing characteristics of the patient case ablated organs and the pathological tumors, assigning values to the ablated organ tissue morphology model by calling the data parameters of the active tissue dielectric characteristic database to form an organ electric pulse ablation basic model with the group characteristics.
The prostate organ active tissue dielectric characteristic database in the embodiment is composed of tissue dielectric characteristic parameters obtained by adopting an active tissue dielectric characteristic measuring method, and database data are continuously enriched along with the increase of the number of cases. The tissue dielectric characteristic parameters are statistical calculation results after multi-sample measurement, and reflect the population characteristics of tissues of different ages and different classifications. For the present embodiment, the patient 62 years old belongs to the malignant prostate tumor stage T2, and the tissue dielectric property parameters include prostate normal tissue region dielectric property parameter, tumor region tissue dielectric property parameter, and tumor marginal region tissue dielectric property parameter.
Part of the parameter table is shown in table 1 below:
table 1: dielectric characteristic parameter of prostate T2 stage cancer tumor and surrounding tissue type
The morphological model shown in fig. 3 is subjected to finite element subdivision, and is divided into a normal tissue region, a cancer tissue region and a pericancer tissue region, and dielectric parameter assignment is carried out according to the parameters in table 1 to form an organ electric pulse ablation basic model with the groupwise characteristic.
(4) Ablation electrode distribution parameter solution
Based on an organ electric pulse ablation basic model, according to an electric pulse ablation electric field setting principle and an electromagnetic field simulation analysis method, establishing organ electric pulse ablation simulation, and forming an ablation electric pulse parameter initial value and an ablation area electrode needle arrangement scheme parameter according to the maximum tumor cross-sectional area and the tumor tissue ablation threshold parameter. And simultaneously carrying out boundary marking on an effective ablation electric field region between the ablation electrode pairs. Wherein the parameter of the needle arrangement scheme refers to the position information of the ablation electrode needle in the lesion ablation area.
In order to more clearly show the needle arrangement position and the effective ablation electric field area between the electrode needle groups, a two-dimensional plan view is used for illustration, as shown in fig. 4. In the embodiment, the ablation electrode needle 1, the electrode needle 2, the electrode needle 3 and the electrode needle 4 are commonly adopted to ablate lesion in a tumor region, and an ablation electric field is formed between the electrode needle groups. According to the ablation threshold parameter of the prostate tumor tissue, the boundary of an ablation electric field region can be obtained between the electrode needles 1 and 2, between the electrode needles 2 and 3 and between the electrode needles 3 and 4 through electromagnetic field simulation calculation.
And step two, according to the electrode needle arrangement scheme of the ablation area, carrying out electrode needle arrangement in the ablation area, obtaining impedance measurement data among needle arrangement electrode groups through an impedance measurement feedback module, and solving dielectric characteristic parameters of the in-vivo tissue.
After the first step is completed in this embodiment, the ablation electrode needle arrangement is performed on the lesion ablation area of the patient according to the needle arrangement scheme, and then the following steps are performed:
(1) Initiating an impedance measurement feedback module to ablate an in vivo measurement of tissue impedance between an electrode pair
In this embodiment, the impedance measurement feedback module can be used as a module of an electrical pulse ablation apparatus, and has a function of measuring the electrical impedance of biological tissues, the embodiment is based on a current excitation-voltage measurement mode, a "two-electrode method" is adopted to measure the in-vivo electrical impedance of tissues between ablation electrode needles, and the measured tissue impedance value between the ablation electrode needle groups is defined as Z s 。
(2) Optimization solution of tissue dielectric characteristic parameters between ablation electrode needle groups
Obtaining tissue-in-vivo electrical impedance data Z between ablation electrode needle groups s Then, the embodiment provides an on-body tissue dielectric parameter (including tissue conductivity σ and dielectric constant ∈) solving method based on the inverse problem optimization solution, that is, the effective ablation electric field region between the ablation electrode needle groups marked in the step one is used as a tissue dielectric characteristic parameter optimization region, as shown in fig. 4, and according to an electromagnetic field analysis principle, a finite element simulation and an inverse problem optimization solution algorithm are combined to obtain on-body tissue dielectric characteristic parameters (including tissue conductivity σ and dielectric constant ∈) between the ablation electrode needle groups. The specific implementation process is as follows:
(i) Finite element model and calculation
Finite element subdivision is carried out on an ablation area, and according to the tissue electrical impedance measurement condition (below 1 MHz), the following equation can be established by combining a Maxwell equation:
J(ω)＝σE(ω)+jωD(ω)+J e (ω)
n.J＝0
in the equation, Q j Denotes current source, σ is conductivity, ω is frequency, J e Represents the external current density and V is the voltage.
The equations can be solved by combining a finite element method, and the impedance Z between the ablation electrode needle groups in the finite element model can be obtained by further utilizing the current-voltage relation M 。
(ii) Optimization solution
The optimal solution equation is established as follows:
f(σ，ε)＝||Z s |-|Z M (σ，ε)||+K|Φ s -Φ M (σ，ε)|
wherein f (sigma, epsilon) is an objective optimization function for solving the biological tissue conductivity sigma and the dielectric constant epsilon, K is a weight coefficient, and Z is s Representing the patient's in vivo measurement of the impedance between the ablation electrode needle sets, | Z s I represents the corresponding impedance mode value, and phi s represents the corresponding impedance phase angle; z is a linear or branched member M Representing the impedance between the ablation needle sets in the finite element model, | Z M I represents the corresponding mode value, phi M Indicating the corresponding phase angle. Sigma L ，σ U Respectively representing the lower limit and the upper limit of the value of the biological tissue conductivity sigma in the optimization iterative solution; epsilon L ，ε U Respectively representing the lower limit and the upper limit of the value of the biological tissue dielectric constant epsilon in the optimization iterative solution.
As shown in the optimization process of FIG. 5, the optimization algorithm is adopted, the optimization algorithm adopted in this embodiment is a TR confidence domain algorithm, the weight coefficient in the optimization function is selected to be 60, where (σ) L ，σ U ) And (epsilon) L ，ε U ) Optimizing parameters in interval, and optimizing initialization parameter (sigma) 0 ，ε 0 ) And continuously performing iterative correction, and obtaining an optimal solution when the value f is the minimum. Wherein (sigma) L ，σ U ) And (ε) L ，ε U ) Representing the range of possible tissue dielectric property parameters at the ablation region of the patient. To increase the solving speed of the algorithm and the convergence of the algorithm optimization process, (σ) L ，σ U ) And (ε) L ，ε U ) May be set based on empirical values that may result from the acquisition of a large sample of multi-patient data.
This example presents tissue high-voltage electrical pulse ablation for prostate tumors, where (σ) L ,σ U ) And (epsilon) L ,ε U ) The values of (c) can be taken with reference to the following table:
and thirdly, performing dielectric characteristic parameter non-uniform reconstruction on the organ electric pulse ablation basic model with the group characteristics established in the first step by using the dielectric characteristic parameter data of the patient in-vivo tissues to form an organ electric pulse ablation individualized model with the in-vivo tissue impedance non-uniform distribution characteristics of the patient. Further optimizing the ablation electrical pulse parameters.
In this embodiment, the implementation method of performing non-uniform reconstruction of the dielectric characteristic parameters on the organ electric pulse ablation basic model with the population characteristics established in the step one by using the dielectric characteristic parameter data of the patient in-vivo tissues to form the organ tissue electric pulse ablation individualized model with the impedance distribution characteristics of the patient in-vivo tissues includes:
(1) And (4) carrying out tissue dielectric characteristic parameter non-uniform reconstruction on the organ electric pulse ablation basic model established in the step one.
And (3) replacing the tissue dielectric property parameters of the corresponding region of the original model with the tissue dielectric property parameters of the inter-electrode needle group of the patient ablation region acquired in the step (II) according to a set rule. For a clearer explanation, the present embodiment will further explain the region between the ablation electrode needles 1 and 2 and the region between the ablation electrode needles 2 and 3 in fig. 4 by using fig. 6.
As shown in fig. 6, the tissue dielectric characteristic parameters in the effective ablation electric field region between the ablation electrode needles 1 and 2 and between the electrode needles 2 and 3 marked in the step one are reset and corrected, that is, the tissue in vivo dielectric characteristic parameters between the electrode needle groups of the ablation region of the patient obtained in the step two are used to replace the dielectric characteristic parameters of the original model, so as to form an organ tissue individualized ablation model with the characteristic of tissue impedance non-uniform distribution.
Further, the dielectric property parameters of the tumor tissue region in the population characteristic model constructed in the first step are uniform. In the second step, the values of the dielectric property parameters of the in-vivo tissues between the ablation electrode needles 1 and 2 and between the ablation electrode needles 2 and 3 can be respectively obtained as P 12 ＝(σ 12 ,ε 12 ) And P 23 ＝(σ 23 ,ε 23 ). Due to the covered area between the electrode needles 1 and 2 and the covered area between the electrode needles 2 and 3There is an overlap between the two regions, so that three regions S1, S2 and S3 are formed, and the dielectric characteristic parameters are set as P for S1 12 S3 is set to P 12 S2 can be set to P 12 And P 23 So that the dielectric characteristic parameters of the tumor tissue area are non-uniformly set according to the actual values of the dielectric characteristic parameters of the in-vivo tissue, and an organ tissue individualized ablation model with the characteristic of tissue impedance non-uniform distribution is formed.
The method for resetting and correcting the tissue dielectric property parameters in the effective ablation electric field region between the ablation electrode needles 2 and 3 and between the electrode needles 3 and 4 is the same as above, and is not repeated.
(2) Ablation electrical pulse parameter optimization based on new model
Further, based on the dielectric characteristic parameter non-uniform individualized ablation model established in the step (1), in combination with an electric pulse ablation electric field setting principle, an electromagnetic field simulation analysis solving method is utilized, and pulse source optimized pulse parameters are determined according to the ablation critical electric field intensity threshold value and the rule that the ablation area covers the lesion area.
It should be noted that the above-mentioned embodiments are only preferred examples for implementing the present invention, and are only convenient for those skilled in the art to fully understand the present invention, and the present invention is not limited to the above-mentioned embodiments. Any non-essential addition or replacement made by a person skilled in the art according to the technical features of the technical solution of the present invention shall fall within the scope of protection defined by the technical solution of the present invention.
Claims (4)
1. The method for optimizing the precision of an electric pulse ablation model based on the inhomogeneous reconstruction of the impedance information of active tissues is characterized in that after a basic model with the group characteristics is constructed, the inhomogeneous reconstruction is further carried out on dielectric property parameters of tissues in an ablation area so as to obtain an optimized model, and the method specifically comprises the following steps:
firstly, extracting case information characteristics of a patient, constructing an organ electric pulse ablation basic model with population characteristics based on the characteristics, and obtaining an initial value of ablation electric pulse parameters and an ablation area electrode needle arrangement scheme;
step two, according to the electrode needle distribution scheme of the ablation area, electrode needle distribution is carried out in the ablation area, impedance measurement data among needle distribution electrode groups are obtained through an impedance measurement feedback module, and in-vivo tissue dielectric characteristic parameter solving is carried out;
step three, utilizing the dielectric characteristic parameter data of the patient in-vivo tissue to carry out dielectric characteristic parameter non-uniform reconstruction on the organ electric pulse ablation basic model with the group characteristic established in the step one so as to form an organ electric pulse ablation individualized model with the patient in-vivo tissue impedance non-uniform distribution characteristic; the ablation electrical pulse parameters are optimized based on the model pulse source.
2. The method as claimed in claim 1, wherein the step one of extracting the case information features of the patient, and constructing the organ electrical pulse ablation basic model with population features based on the features to obtain the ablation electrical pulse parameters and the ablation zone electrode needle arrangement scheme is implemented by:
(1) Patient case information feature extraction
The method for extracting the case information characteristics of the patient mainly comprises the following steps: ablation of imaging and histology information of organs and diseased tumors;
(2) Three-dimensional reconstruction ablation organ morphology model
Establishing a three-dimensional model of an ablation organ by using a three-dimensional reconstruction technology based on imaging data of the ablation organ of a patient, wherein the model comprises a main tissue area of the organ;
the main tissue area of the ablation organ at least comprises a normal tissue area, a tumor tissue area and a tumor marginal tissue area;
(3) Assignment of dielectric property parameters to living biological tissues
According to the histology classification typing characteristics of the patient case ablation organ and the pathological tumor, the active tissue dielectric characteristic database data parameters are called to assign values to the ablation organ tissue morphology model, and an organ electric pulse ablation basic model with the group characteristics is formed;
the active tissue dielectric characteristic database is composed of tissue dielectric characteristic parameters obtained by an active tissue dielectric characteristic measuring method, and database data are continuously enriched along with the increase of the number of cases; the tissue dielectric characteristic parameters are statistical calculation results after multi-sample measurement, and reflect the population characteristics of tissues of different age groups and different classifications;
the dielectric characteristic parameters comprise a dielectric characteristic parameter of a normal tissue region of an organ, a dielectric characteristic parameter of a tissue of a tumor area and a dielectric characteristic parameter of a tissue of a tumor marginal area;
(4) Ablation electrode distribution parameter solution
Establishing an organ electric pulse ablation simulation based on an organ electric pulse ablation basic model, according to an electric pulse ablation electric field setting principle and an electromagnetic field simulation analysis method, and forming an ablation electric pulse parameter initial value and an ablation area electrode needle arrangement scheme parameter according to the maximum cross-sectional area of a tumor and the ablation threshold parameter of tumor tissues; simultaneously, carrying out boundary marking on effective ablation electric field regions between the ablation electrodes;
the needle arrangement scheme parameter refers to the position information of the ablation electrode needle in the lesion area.
3. The method of claim 1, wherein the step two of performing electrode needle distribution in the ablation region of the patient organ according to the ablation region electrode needle distribution scheme, acquiring impedance measurement data between the needle distribution electrode pairs through the impedance measurement feedback module, and performing in-vivo tissue dielectric property parameter solution is performed by:
(1) In vivo measurement of tissue impedance between ablation electrode pairs
The impedance measurement feedback module adopts a multi-frequency current excitation-voltage measurement mode to measure the in-vivo electrical impedance of tissues between ablation electrode needles to obtain tissue electrical impedance parameters;
(2) Optimization solution of tissue dielectric characteristic parameters between ablation electrode needle groups
And (3) according to the in-vivo electrical impedance parameter data of the tissues among the ablation electrode needle groups, taking the effective ablation electric field region among the ablation electrode needle groups marked in the step one as a tissue dielectric characteristic parameter optimization region, and combining finite element simulation and an inverse problem optimization solving algorithm to obtain in-vivo dielectric characteristic parameters of the tissues among the ablation electrode needle groups.
4. The method as claimed in claim 1, wherein the step three of using the patient-in-vivo tissue dielectric property parameter data to perform the dielectric property parameter non-uniform reconstruction on the organ electric pulse ablation basic model with the population characteristics established in the step one to form the organ tissue electric pulse ablation individualized model with the patient-in-vivo tissue impedance distribution characteristics is implemented by:
(1) Carrying out non-uniform reconstruction of tissue dielectric characteristic parameters on the ablation region in the organ electric pulse ablation basic model established in the step one;
the tissue dielectric characteristic parameters are subjected to non-uniform reconstruction, namely the tissue dielectric characteristic parameters of the regions corresponding to the original model are replaced by the tissue in-vivo dielectric characteristic parameters of the electrode pin groups of the ablation regions of the patient, which are obtained in the step two, according to a set rule;
(2) And optimizing the parameters of the ablation electric pulse based on the new model.
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| CN117695005A (en) * | 2024-02-05 | 2024-03-15 | 浙江伽奈维医疗科技有限公司 | Steep pulse treatment system with needle distribution guiding function |
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| CN117695005A (en) * | 2024-02-05 | 2024-03-15 | 浙江伽奈维医疗科技有限公司 | Steep pulse treatment system with needle distribution guiding function |
| CN117695005B (en) * | 2024-02-05 | 2024-05-07 | 浙江伽奈维医疗科技有限公司 | Steep pulse treatment system with needle distribution guiding function |
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