Method for achieving ablation marking through electric field control

Abstract

The invention relates to the field of medical equipment, and discloses a method for realizing ablation marking by controlling an electric field, which comprises the following steps of: applying an ablation pulse field to an ablation site on target tissue for ablation treatment; after the ablation treatment, acquiring biological impedance change information of the ablation site, and determining the ablation quality grade of the ablation treatment according to the information; according to the determined ablation quality grade, selecting a corresponding non-destructive electrical characteristic coding sequence; the selected electrical feature coding sequence is applied to the ablation site, and a marker associated with an ablation quality level is formed on the site. Informationized and non-thermalized marking is achieved in a pure electric control mode, the mark can bear ablation quality state information, and the technical problem that after pulse field ablation, the position and effect of an ablation site are difficult to identify in real time due to the fact that the ablation site has no obvious change on the macroscopic level of the tissue is solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of medical equipment, in particular to a method for realizing ablation marking by controlling electric field. BACKGROUND

[0002] Atrial fibrillation is one of the most common arrhythmia diseases, and catheter ablation is an important treatment method. The operation causes permanent damage or death of cells by applying energy to specific target tissues in the atrium, thereby blocking the conduction path of abnormal electrical signals. The ablation energy forms used in clinical practice mainly include radiofrequency ablation and cryoablation, both of which achieve tissue necrosis through thermal effect (heating or freezing).

[0003] In recent years, pulsed field ablation (PFA) as a new non-thermal ablation technology has shown great application prospects. PFA forms irreversible nanoscale pores on the cell membrane by applying high-voltage, microsecond-level electric pulses, i.e. irreversible electroporation, thereby causing cell apoptosis. Its core advantage lies in tissue selectivity, which can effectively ablate myocardial tissue while minimizing thermal damage to adjacent esophagus, nerves and other non-myocardial tissues, significantly improving the safety of the operation.

[0004] However, due to its non-thermal ablation mechanism, PFA technology also poses a technical problem that needs to be solved. Unlike radiofrequency ablation, which produces clear visible white coagulation necrosis lesions, PFA-treated tissues show almost no immediate visible changes in macroscopic morphology. This makes it difficult for the operator to directly identify the areas where ablation has been completed during the operation by visual inspection or conventional imaging methods, and it is impossible to accurately judge the continuity and integrity of the ablation line. Currently, the operator mainly relies on virtual marker points left on the heart model by the three-dimensional electroanatomical mapping system to track the ablation path, but this method has the risk of displacement of the marker points and the actual tissue position due to breathing or heartbeats, affecting the accuracy of ablation.

[0005] In addition, the evaluation of ablation effect in the prior art is usually indirect by monitoring parameters such as biological impedance drop and contact force at the moment of applying ablation energy, and a simple virtual position marker point is placed on the three-dimensional model. This marker only records the position information that an operation has been performed at this point, and does not carry quality information about "how effective the operation is". Once the ablation catheter leaves the site, the ablation quality information of the site is no longer directly associated with the physical tissue. When the operator needs to review and evaluate the quality of the entire ablation line and find gaps, the lack of direct, objective and solidified information carriers on the tissue makes the decision-making process of the point operation operation heavily dependent on the experience and memory of the operator, increasing the uncertainty and recurrence risk of the operation.

[0006] Therefore, there is an urgent need in the art for a new technical means that can not only effectively mark the ablation site after PFA, but also be compatible with the non-thermal characteristics of PFA during the marking process itself; at the same time, the marking should also be able to carry and reflect the ablation quality information, so as to provide accurate and objective intraoperative decision basis for the operator, so as to improve the success rate of the operation. SUMMARY

[0007] The present application aims to solve the problem in the prior art that after pulse field ablation, due to the non-thermal effect characteristics, there is no obvious morphological change in the ablation site at the macroscopic level of the tissue, thereby leading to the difficulty in identifying the ablated region and its ablation effect in real time and accurately during the operation.

[0008] To solve the above technical problems, the present application provides a method for ablation marking by controlling electric field. The method forms an electrical marker on the ablation site by actively applying a special coded and non-damaging electric field sequence to the target tissue after the standard ablation process, so as to be detected, decoded and characterized by the ablation quality.

[0009] Specifically, the technical solution provided by the present application comprises the following steps: S1, applying an ablation pulse field to the ablation site on the target tissue for ablation treatment. The ablation treatment in this step can be single-point ablation on a single target site, or continuous application to multiple adjacent sites or synchronous application by using a multi-electrode array to form a linear or planar ablation region, so as to effectively treat a larger range of tissue. The ablation pulse field is usually a series of high-intensity, narrow-pulse-width pulses, which aims to achieve tissue ablation through irreversible electroporation effect.

[0010] S2, after the ablation treatment, obtaining the biological impedance change information of the target tissue at the ablation site, and determining the ablation quality grade of this ablation treatment according to the information. This step specifically comprises: respectively obtaining the reference biological impedance of the ablation site before applying the ablation pulse field, denoted as Z pre , and the post-ablation biological impedance of the ablation site after applying the ablation pulse field, denoted as Z post .

[0011] Based on the obtained Z pre and Z post , the relative biological impedance drop rate D Z is calculated. The calculation method is as follows: The calculated D Z is compared with the preset ablation quality grading threshold to determine the ablation quality grade. For example, the preset optimal ablation threshold Topt and an acceptable ablation threshold T acc When D Z ≥ T opt , the ablation quality level is determined as an optimal level; when T acc ≤ D Z < T opt , it is determined as an acceptable level; and when D Z < T acc , it is determined as a suboptimal level.

[0012] S3, selecting an electrical characteristic encoding sequence corresponding to the determined ablation quality level from at least two preset electrical characteristic encoding sequences. The electrical characteristic encoding sequences are pre-designed and stored, for example, three different electrical characteristic encoding sequences corresponding to the optimal level, the acceptable level and the suboptimal level are respectively preset.

[0013] The electrical characteristic encoding sequence is a non-invasive high-frequency alternating composite pulse field. The electric field strength is controlled below the irreversible electroporation threshold of the target tissue to ensure that the marking process does not cause additional tissue damage. At the same time, in order to distinguish from the ablation pulse field used for treatment, the high-frequency alternating composite pulse field can be formed by pulse width modulation or frequency modulation of the high-frequency carrier, so that it carries specific encoding information.

[0014] S4, applying the selected electrical characteristic encoding sequence to the ablation site to form a mark associated with the ablation quality level on the ablation site.

[0015] In some embodiments of the present application, the method further comprises a subsequent decoding and displaying step. In order to further improve the security and exclusivity of the marking information, the electrical characteristic encoding sequence can be embedded with an encryption algorithm or a specific signature, so that the formed mark not only carries the ablation quality level information, but also has the characteristics of information encryption and anti-counterfeiting. After applying the electrical characteristic encoding sequence, the ablation site must be detected by a matching special decryption device. The special device is built-in with a decryption key and verification logic matching the encryption algorithm or specific signature, which can first authenticate the validity of the mark, and then safely decode the ablation quality level associated with the mark. This ensures that only authorized devices can correctly read and analyze the ablation quality information, effectively preventing data from being stolen or tampered by unauthorized devices, and ensuring the reliability of the final presentation result. Subsequently, the ablation site is displayed differentially according to the decoded ablation quality level. For example, the ablation sites corresponding to the optimal level, the acceptable level and the suboptimal level are displayed in different colors respectively.

[0016] This invention provides a method for ablation marking through electric field control. It has the following beneficial effects: 1. This invention forms a marker by applying a non-damaging electrical feature encoding sequence to the target tissue after ablation treatment. This process is completed in a purely electrical control manner without generating additional thermal damage, thereby achieving effective marking while fully maintaining the inherent non-thermal safety advantages of pulse field ablation technology.

[0017] 2. This invention establishes a correspondence between bioimpedance change information and specific electrical characteristic coding sequences, enabling the final marker to be directly associated with the ablation quality level. This allows the marker to not only indicate the location of the ablation operation but also carry key information about the ablation effect at that location, greatly enhancing the dimensionality and value of intraoperative information compared to traditional marker methods that only provide location information.

[0018] 3. This invention, by decoding and differentially displaying markers carrying ablation quality level information, provides operators with intuitive feedback on the ablation quality at each point along the ablation path. This feedback provides accurate and reliable objective basis for subsequent operations such as point addition, energy adjustment, or correction of surgical strategies, helping to improve the accuracy and success rate of the surgery. Attached Figure Description

[0019] Figure 1 This is a flowchart illustrating a method for implementing ablation marking by controlling an electric field according to an embodiment of the present invention. Figure 2 This is a flowchart illustrating a method for determining ablation quality level according to an embodiment of the present invention; Figure 3 This is a flowchart illustrating the design and application of an electrical feature encoding sequence method according to an embodiment of the present invention; Figure 4 This is a flowchart illustrating a tag decoding and rendering method according to an embodiment of the present invention; Figure 5 This is a circuit block diagram of one embodiment of the present invention. Detailed Implementation

[0020] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] See attached document Figure 1 With appendix Figure 5 , Figure 1This is a flowchart illustrating a method for implementing ablation marking by electric field control according to an embodiment of the present invention. The present invention provides a method for implementing ablation marking by electric field control, which may include the following steps: S1, apply an ablation pulse field to the ablation site on the target tissue for ablation treatment.

[0022] S2. After ablation, obtain information on the changes in bioimpedance of the target tissue at the ablation site, and determine the ablation quality level of this ablation treatment based on the information on the changes in bioimpedance.

[0023] S3, based on the ablation quality level, select one electrical feature coding sequence corresponding to the ablation quality level from at least two preset electrical feature coding sequences.

[0024] S4, apply the selected electrical feature encoding sequence to the ablation site to form a marker on the ablation site that is associated with the ablation quality level.

[0025] The method flow disclosed in this embodiment will be described in detail below.

[0026] This method begins with a standard ablation procedure performed on a specific ablation site on a target tissue (e.g., myocardial tissue). This procedure is accomplished by applying an ablation pulse field via S1, which is a series of high-intensity, narrow-pulse pulses designed to induce irreversible electroporation of the cells.

[0027] After ablation, the method enters an immediate evaluation and labeling process. First, step S2, determining the ablation quality level, is performed. The core of this step is quantifying the impact of the ablation process on the electrophysiological characteristics of the ablation site. Specifically, through measurement operations, the baseline bioimpedance (Z-strain) before the application of the ablation pulse field is obtained. pre ) and post-ablation bioresistance (Z) post Subsequently, based on these two impedance values, the relative decrease rate D of bioimpedance was calculated. Z The calculation formula is as follows: Among them: Z pre Z represents the reference bioimpedance. post This represents bioresistance after ablation.

[0028] The relative decrease rate D of bioimpedance was calculated. Z Then, it is compared with the ablation quality grading threshold preset in the control logic to determine a discrete ablation quality level.

[0029] Next, the method performs an adaptive coding sequence selection step S3, which selects a unique electrical feature coding sequence corresponding to the ablation quality level from a preset library containing at least two different electrical feature coding sequences, based on the ablation quality level determined in step S2.

[0030] In a further implementation, the selection logic in step S3 is upgraded intelligently by introducing a machine learning module. This module is pre-trained to directly use the bioimpedance data acquired in step S2 (not limited to the final calculated relative decrease rate of bioimpedance, but also including baseline bioimpedance, the original value of bioimpedance after ablation, and even dynamic process data of impedance changes) as input features. Through its complex internal decision model, this module can automatically and accurately classify the input impedance data patterns to the most suitable electrical feature encoding sequence and output the selection result. Compared to the level determination method based on a fixed threshold, this machine learning-driven selection method can capture more subtle and nonlinear features in the impedance data, thereby achieving a more refined distinction of ablation quality and a more robust adaptive selection of encoding sequences.

[0031] For example, if the ablation quality level is determined to be optimal, or if the machine learning module identifies a feature pattern that matches the optimal ablation from the input impedance data combination, it will automatically select and output the corresponding optimal coding sequence.

[0032] Finally, step S4, which involves applying an electrical marker, is performed. The electrical feature encoding sequence selected in step S3 is applied to the current ablation site via an electrode. This sequence is a non-invasive pulsed electric field. The application process aims to change the electrical properties of the local tissue, thereby forming a stable, detectable electrical marker at the ablation site that is directly related to the quality level of the ablation treatment without any change in macroscopic morphology. The formation of the marker provides a foundation for subsequent detection, identification, and visualization.

[0033] See attached document Figure 2 , Figure 2 This is a flowchart illustrating a method for determining the ablation quality level according to an embodiment of the present invention. After the ablation treatment in step S1 is completed, step S2, which determines the ablation quality level, begins. This step is used to objectively quantify the impact of the aforementioned ablation treatment on the electrophysiological characteristics of the ablation site, and its specific process may include: S201. Obtain the baseline bioimpedance and post-ablation bioimpedance of the ablation site.

[0034] S202. Calculate the relative decrease rate of bioimpedance.

[0035] S203. Compare the relative decrease rate of bioimpedance with the preset ablation quality grading threshold to determine the ablation quality level.

[0036] In step S201, the bioimpedance acquisition is performed precisely twice. The first time is instantaneously before the application of the ablation pulse field, by applying a weak probe current to the ablation site and measuring its response to obtain the reference bioimpedance of that site, denoted as Z. pre The second measurement was taken after the sequence of ablation pulses was applied, keeping the probe electrode position unchanged, and measuring again in the same manner to obtain the post-ablation bioimpedance at that site, denoted as Z. post In step S202, based on the two bioimpedance measurements obtained in S201, the relative rate of decrease in bioimpedance D is calculated. Z This parameter reflects the degree of damage to the integrity of tissue cell membranes caused by irreversible electroporation, thus characterizing the effectiveness of ablation. The calculation formula is as follows: Among them, Z pre Z is the reference bioimpedance. post For post-ablation bioimpedance, D Z The relative decrease rate of bioimpedance is denoted as D. In step S203, the relative decrease rate of bioimpedance D calculated in S202 is used. Z A discrete ablation quality level is obtained by comparing the ablation quality level with at least one pre-defined ablation quality grading threshold in the method logic. In this embodiment, two thresholds are pre-defined: the optimal ablation threshold T. opt and acceptable ablation threshold T acc .

[0037] The specific judgment logic is as follows: when the calculated D Z Greater than or equal to the optimal ablation threshold T opt When D is selected, the ablation quality level of this ablation treatment is determined to be the optimal level; when D Z Less than the optimal ablation threshold T opt But greater than or equal to the acceptable ablation threshold T acc When D is selected, the ablation quality level is determined to be acceptable; when D Z Less than the acceptable ablation threshold T acc If the ablation quality level is determined to be suboptimal, then the output of this step, i.e., the determined ablation quality level, will directly serve as the input for selecting the electrical feature coding sequence in the next step.

[0038] In step S201, the bioimpedance of the ablation site is acquired to provide basic data for subsequent calculation of the relative decrease rate of bioimpedance. This acquisition process is completed through two independent measurement operations to ensure that the data reflect the tissue electrical properties before and after the ablation treatment.

[0039] The first measurement is performed before the ablation pulse field is applied in step S1. Specifically, immediately after the ablation command is triggered but just before the high-intensity ablation pulse field is actually applied, a preset weak probe current is applied to the ablation site through the electrode in contact with the target tissue. The parameters of this probe current (such as frequency and amplitude) are set within a range that does not produce any physiological stimulation or tissue damage. By measuring the voltage response generated by this probe current in the tissue, the bioimpedance value at that moment can be calculated and recorded according to Ohm's law. This value is defined as the reference bioimpedance Z. pre ° The second measurement was performed immediately after the completion of the complete sequence of ablation pulse fields applied in step S1. To ensure the comparability of the two measurements, a key technical condition is that the physical position and contact state of the electrodes applying the probe current and ablation pulse field with the ablation site remain unchanged throughout the entire period from the completion of the first to the completion of the second measurement. Under this condition, the reference bioimpedance Z was obtained. pre Using the exact same method and parameters, a weak probe current was applied again, and the response was measured. The bioimpedance value at that moment was calculated and recorded; this value was defined as the post-ablation bioimpedance Z. post , In step S201, the baseline bioimpedance Z was obtained. pre and post-ablation bioresistance Z post The method then proceeds to step S202, which involves calculating the relative decrease rate of bioimpedance.

[0040] This step aims to transform two independent impedance measurements into a single, standardized quantitative indicator to characterize the extent to which ablation alters the electrophysiological properties of the tissue. Since irreversible electroporation disrupts cell membrane integrity, leading to increased ion pathways within the tissue and macroscopically manifested as a decrease in bioimpedance, the relative decrease in bioimpedance directly reflects the effectiveness of the ablation.

[0041] Relative decrease rate of bioimpedance D Z The specific calculation formula is as follows: Among them: Z pre Z is the baseline bioimpedance obtained in step S201; post The post-ablation bioimpedance obtained in step S201; D Z To calculate the relative decrease rate of bioimpedance, the output of the calculation step is a dimensionless numerical value D. Z This value will be used in the subsequent S203 step as a direct basis for comparison with the preset ablation quality grading threshold.

[0042] In step S202, the relative decrease rate D of bioimpedance is calculated. Z Following this, the method proceeds to step S203, the purpose of which is to convert the continuous value D produced in the previous step into a continuous value D. Z This is transformed into a discrete ablation quality level with clear technical meaning. The determination process is based on the relative decrease rate of bioimpedance D. Z This is achieved by comparing the ablation quality grading thresholds pre-set in the method control logic. In this embodiment, the control logic presets two independent threshold parameters: the optimal ablation threshold T. opt and acceptable ablation threshold T acc .

[0043] The specific decision-making logic is divided into three mutually exclusive conditional branches: The first scenario is when the relative decrease rate D of bioimpedance calculated in step S202... Z Greater than or equal to the optimal ablation threshold T opt Time (i.e., D) Z ≥T opt If the ablation quality level of this ablation treatment is determined to be the optimal level, then the quality level of this ablation treatment is determined to be the optimal level.

[0044] The second scenario is when the relative decrease rate of biological impedance D Z Less than the optimal ablation threshold T opt However, it is also greater than or equal to the acceptable ablation threshold T. acc Time (i.e., T) acc ≤D Z <T opt If the ablation quality level of this ablation treatment is determined to be acceptable, then the ablation quality level is determined to be acceptable. The third case is when the relative decrease rate of bioimpedance D... Z Less than the acceptable ablation threshold T acc Time (i.e., D) Z <T acc If the ablation quality level of this ablation treatment is determined to be suboptimal, then the quality level of this ablation treatment is determined to be suboptimal.

[0045] By performing the above comparisons and judgments, step S203 ultimately outputs a definite ablation quality level (i.e., one of the best level, acceptable level, or second-best level). This output will serve as the direct input basis for selecting a specific electrical feature encoding sequence in the subsequent step S3.

[0046] See attached document Figure 3 , Figure 3This is a flowchart illustrating a method for designing and applying an electrical feature encoding sequence according to an embodiment of the present invention. After determining the ablation quality level of the current ablation treatment in step S2, the method enters the electrical marker formation stage. This stage aims to transform the aforementioned evaluation-derived level information into a detectable electrical feature at the ablation site by applying a specific electric field sequence. This stage may specifically include: S301. Select a corresponding preset electrical feature coding sequence based on the ablation quality level.

[0047] S302. Apply the selected electrical feature coding sequence to the ablation site to form a marker.

[0048] In step S301, the ablation quality level (i.e., optimal, acceptable, or suboptimal level) output from step S203 is used as the direct input for this step. The method pre-defines at least two electrical feature encoding sequences, and each sequence establishes a one-to-one correspondence with a specific ablation quality level. For example, pre-define sequence A corresponds to the optimal level, sequence B to the acceptable level, and sequence C to the suboptimal level. The execution process of this step involves searching for and selecting the uniquely matching electrical feature encoding sequence from the pre-defined correspondence based on the input ablation quality level.

[0049] In step S302, the electrical feature encoding sequence selected in S301 is applied to the current ablation site. This application process involves outputting a specially designed pulsed electric field to the same tissue location through the same electrode after ablation and impedance measurement. The application of this pulsed electric field creates a marker on the local tissue that is consistent with the electrical characteristics of the applied sequence and can be detected by external devices, thus completing the process of solidifying the abstract ablation quality level information into a physically measurable feature.

[0050] The electrical signature encoding sequence itself is a non-invasive high-frequency AC composite pulse field. Its non-invasiveness is achieved by strictly controlling its electric field strength below the irreversible electroporation threshold of the target tissue, ensuring that the labeling process does not produce any additional cell ablation or tissue damage.

[0051] To ensure that different electrical feature coding sequences have a distinguishable and unique identifier, a high-frequency AC composite pulse field is formed by modulating a high-frequency carrier wave. For example, pulse width modulation can be used to set different pulse width combinations for sequences corresponding to different ablation quality levels; or frequency modulation can be used to set different frequency variation patterns. This modulation gives each coding sequence a unique electrical fingerprint, providing a foundation for subsequent accurate decoding.

[0052] Electrical feature coding sequence is essentially a specially designed non-invasive high-frequency AC composite pulse field used to carry ablation quality level information.

[0053] A fundamental characteristic of the electrical signature coding sequence is its non-invasiveness. This characteristic is achieved through precise control of the applied electric field strength. Specifically, the peak electric field strength of the high-frequency AC composite pulse field is set and maintained at a level below the irreversible electroporation threshold of the target tissue. This setting ensures that no additional cell ablation or thermal damage is caused to the ablation site and surrounding tissue throughout the entire process of applying the coding sequence to form the marker.

[0054] Another fundamental characteristic of electrical feature coding sequences is their high frequency. The composite pulse field consists of a high-frequency AC carrier wave, the frequency of which is selected within a specific high-frequency range. The technical advantage of selecting a high-frequency carrier wave is that it can avoid or significantly reduce the electrical stimulation effect on nerve and muscle tissue within the target tissue region, thereby preventing unintended muscle contractions during labeling.

[0055] To enable different electrical feature coding sequences to carry different information (i.e., corresponding to different ablation quality levels) and possess a unique identifier that can be distinguished by external devices, a high-frequency AC composite pulse field is formed by modulating a high-frequency carrier. In this embodiment, this modulation can be achieved through pulse width modulation or frequency modulation.

[0056] When pulse width modulation (PWM) is used, an electrical feature encoding sequence consists of a series of high-frequency pulses with different pulse widths. For example, a pulse with a preset width of W1 represents the optimal level, and a pulse with a preset width of W2 represents the acceptable level. In step S301, if the determined ablation quality level is the optimal level, then a pulse sequence with a width of W1 is selected; if it is the acceptable level, then a pulse sequence with a width of W2 is selected.

[0057] When frequency modulation is used, an electrical feature coding sequence consists of a series of high-frequency pulses with different carrier frequencies. For example, a pulse sequence with a carrier frequency of F1 is preset to represent the optimal level, a pulse sequence with a carrier frequency of F2 represents the acceptable level, and a pulse sequence with a carrier frequency of F3 represents the suboptimal level.

[0058] In step S301, a pulse sequence containing a specific carrier frequency is selected and applied based on the determined ablation quality level. In this way, each ablation quality level corresponds to a unique and precisely identifiable electrical signature.

[0059] After determining the ablation quality level in step S2 and pre-setting an electrical feature encoding sequence corresponding one-to-one with each ablation quality level in the method, the method performs the conversion process of the level information into physical markers. This process is adaptive, and the selection and application of actions depend entirely on the evaluation results of the preceding steps.

[0060] The process first executes step S301, which selects a corresponding preset electrical feature encoding sequence based on the determined ablation quality level. This step is a logical matching and selection operation. Specifically, the ablation quality level output from step S203 (e.g., optimal level, acceptable level, or suboptimal level) is used as the sole input for this step. A predetermined correspondence table is pre-established and stored in the method, binding each ablation quality level to a unique electrical feature encoding sequence. This step searches this correspondence table based on the input ablation quality level and outputs the matching electrical feature encoding sequence. For example, if the input level is optimal, the preset sequence corresponding to the optimal level is selected and output.

[0061] Following sequence selection in step S301, the method executes step S302, which involves applying the selected electrical feature encoding sequence to the ablation site. This step is a physical application operation. To ensure precise alignment between the marking and ablation sites, the application operation is performed using the same electrode used for the ablation process in step S1 and the impedance measurement in step S201, while the electrode remains in physical contact with the ablation site. The selected electrical feature encoding sequence is loaded and drives the electrode to apply the non-invasive high-frequency AC composite pulse field to the target tissue.

[0062] The application of this pulsed field causes a controllable change in the local electrical properties of the ablation site, directly related to the coding characteristics of the applied sequence (such as pulse width and frequency). This change in electrical properties constitutes the marker. Thus, a stable electrical marker representing the quality level of this ablation treatment, detectable by external equipment, is formed at the ablation site.

[0063] In another alternative embodiment of the invention, a marking method that can generate direct visual feedback is also provided. This method is designed to meet the needs of operators in specific scenarios where they require quick and intuitive confirmation of successful ablation.

[0064] In this implementation, when the ablation quality level determined in step S2 is the highest level (e.g., the optimal level), step S3 selects a visual marker-specific electrical coding sequence. Unlike the aforementioned non-invasive coding sequences, the electrical parameters of this visual marker sequence (such as higher local energy density, specific pulse combinations, or slightly longer action time) are precisely set to a level that just exceeds the coagulation or denaturation threshold of the superficial tissue, but is far below the level that would cause deep damage.

[0065] Subsequently, after applying this specific sequence in step S4, it causes a controlled, slight alteration of physical properties at the very superficial layer of the ablation site, such as the formation of a tiny white coagulation spot. The extent and depth of this alteration are strictly limited and do not affect the overall safety of the ablation, but it is macroscopically sufficient to be observed directly by the operator with the naked eye or under an endoscope.

[0066] The biggest advantage of this visual labeling method is that it eliminates the need for subsequent detection, decoding, and display processes.

[0067] Successful ablation is marked in the most intuitive way, greatly simplifying the confirmation process. This method can complement the aforementioned electrical grading marking method. For example, the system can be set to apply visual marking only to ablation points of the optimal grade, while other grades leave no visible trace or still use electrical marking, thus providing the operator with a clear visual reference.

[0068] See attached document Figure 4 , Figure 4 This is a flowchart illustrating a marker decoding and presentation method according to an embodiment of the present invention. After forming a marker associated with the ablation quality level on the ablation site in step S4, the method provided by the present invention further includes a subsequent step of utilizing the marker. It should be noted that this subsequent step mainly corresponds to the aforementioned non-invasive electrical marking implementation method. If an implementation method that generates direct visual markers is used, the operator can confirm the marker directly with the naked eye, without needing to perform the detection, decoding, and display steps shown in this flowchart. This subsequent step aims to convert the electrical marker information already solidified on the tissue into feedback that can be perceived by the operator, and may specifically include: S401. Detect ablation sites and decode the ablation quality level associated with the markers; S402. Based on the decoded ablation quality level, the ablation sites are displayed differently. In step S401, the method performs the detection and decoding of the marker. This operation can be performed using an external detection device, for example, by using the same electrode previously used for ablation and marking to scan and probe within the target tissue area. When the detection electrode passes a marked ablation site, the electrical response signal at that site is acquired and analyzed to identify the electrical characteristics (e.g., a specific pulse width or carrier frequency) unique to the electrical feature encoding sequence applied to that site. Subsequently, based on a pre-defined correspondence consistent with that used in step S301 within the method logic, the identified electrical characteristics are reverse-analyzed into a uniquely corresponding ablation quality level.

[0069] In step S402, the method performs a differential display operation of the ablation quality level. The ablation quality level decoded from step S401 is used as input for this step. The method maps this level information to a preset visual presentation scheme. For example, if the optimal level, acceptable level, and suboptimal level are pre-defined to correspond to three different colors (e.g., green, yellow, and red), this step selects the corresponding color based on the input ablation quality level and marks it with that color at the corresponding position representing the ablation site on a display interface.

[0070] By performing the above-mentioned detection, decoding, and differential display steps, invisible electrical markers and the ablation quality information they carry can be transformed into a visual map that the operator can intuitively perceive, providing an objective basis for intraoperative decision-making.

[0071] In step S401, to convert the formed physical markers into usable information, the method first performs a probe operation on the ablation site. This probe operation can be performed after the ablation procedure by moving and scanning the surface region of the target tissue using the same electrode used to apply the ablation pulse field and the electrical feature encoding sequence.

[0072] When the electrode passes a marked ablation site during the scanning process, signal acquisition and decoding are performed. Specifically, a preset, non-invasive probe signal is applied to the tissue location currently in contact with the electrode, and the electrical response signal at that location is measured simultaneously. When the electrode is located on a marked site, the measured electrical response signal will contain feature information corresponding to the electrical feature encoding sequence applied at that site.

[0073] The acquired electrical response signals are then processed to decode the ablation quality level associated with the marker. This decoding process includes a feature extraction step and an information mapping step.

[0074] In the feature extraction step, the electrical response signal is analyzed to identify the unique electrical features it contains. If the marker is formed using pulse width modulation, this step measures the pulse width of the signal to obtain a specific width value (e.g., W1 or W2). If the marker is formed using frequency modulation, this step performs spectral analysis on the signal to identify its unique carrier frequency (e.g., F1, F2, or F3).

[0075] In the information mapping step, the unique electrical feature extracted in the previous step (i.e., the specific pulse width or frequency value) is compared with the pre-defined correspondence in the method logic. This correspondence is the inverse of the correspondence used to select the encoding sequence in step S301. By searching within this correspondence, the extracted electrical feature can be reverse-analyzed into its unique corresponding ablation quality level (i.e., optimal level, acceptable level, or suboptimal level). The final output of this step is the decoded ablation quality level, which will serve as the input for step S402.

[0076] After decoding the ablation quality level in step S401, the method then proceeds to step S402 to convert the decoded information into a form that can be intuitively perceived by the operator.

[0077] The core of this step lies in mapping the discretized ablation quality levels (i.e., optimal, acceptable, or suboptimal levels) output by S401 to a preset visual presentation scheme. In this embodiment, differentiated display is achieved by mapping different ablation quality levels to different colors, and the mapping relationship is pre-established and stored in the method logic.

[0078] A specific mapping scheme may include: The optimal level is associated with a first preset color (e.g., green); The acceptable level is matched with a second preset color (e.g., yellow); The suboptimal level is associated with the third preset color (e.g., red).

[0079] After step S401 decodes the quality level of a specific ablation site, this step finds the preset color corresponding to that level based on the preset mapping relationship mentioned above.

[0080] Subsequently, on a display interface, the corresponding positions representing ablation sites are rendered or marked with colors. By repeatedly executing the detection decoding step S401 and the differential display step S402, as the probe electrode moves in the target tissue area, a visual ablation quality distribution map will be gradually constructed on the display interface. Different colors will intuitively present the ablation effect of each marked ablation site, providing the operator with objective and clear visual feedback.

Claims

1. A method of implementing an ablation marker under control of an electric field, characterized by, The method comprises the following steps: S1, applying an ablation pulse field to an ablation site of a target tissue for ablation treatment; S2, after the ablation treatment, obtaining biological impedance change information of the target tissue, and determining an ablation quality level of the ablation treatment according to the biological impedance change information; S3, presetting at least two electrical characteristic coding sequences according to the ablation quality level, and selecting one of the electrical characteristic coding sequences corresponding to the ablation quality level; S4, applying the selected electrical characteristic coding sequence to the target tissue to form a mark associated with the ablation quality level on the target tissue.

2. The method of claim 1, wherein the ablation mark is implemented by controlling the electric field. The ablation quality level determination step comprises: respectively obtaining a reference biological impedance of the ablation site in the S1 step and an ablation-after biological impedance of the ablation site after the ablation pulse field is applied; calculating a biological impedance relative drop rate based on the reference biological impedance and the ablation-after biological impedance; comparing the biological impedance relative drop rate with a preset ablation quality grading threshold to determine the ablation quality level.

3. The method of claim 2, wherein the ablation mark is implemented by controlling the electric field. The ablation quality grading threshold comprises an optimal ablation threshold and an acceptable ablation threshold, and is specifically used for: when the biological impedance relative drop rate is greater than or equal to the optimal ablation threshold, determining that the ablation quality level is an optimal level; when the biological impedance relative drop rate is less than the optimal ablation threshold but greater than or equal to the acceptable ablation threshold, determining that the ablation quality level is an acceptable level; when the biological impedance relative drop rate is less than the acceptable ablation threshold, determining that the ablation quality level is a suboptimal level.

4. The method of claim 3, wherein the ablation mark is implemented by controlling the electric field. The at least two electrical characteristic coding sequences correspond to the optimal level, the acceptable level and the suboptimal level respectively.

5. The method of claim 1, wherein the ablation mark is implemented by controlling the electric field. The electrical characteristic coding sequence is a non-invasive high-frequency alternating composite pulse field.

6. The method of claim 5, wherein the ablation mark is implemented by controlling the electric field. The electric field intensity of the high-frequency alternating composite pulse field is lower than an irreversible electroporation threshold of the target tissue.

7. The method of claim 5, wherein the ablation mark is implemented by controlling the electric field. The high-frequency alternating composite pulse field is formed by pulse width modulation or frequency modulation on a high-frequency carrier.

8. The method of claim 1, wherein the ablation mark is implemented by controlling the electric field. The method for realizing ablation marking by electric field control further comprises: after the electrical characteristic coding sequence is applied, detecting the ablation site by an external device to decode the ablation quality level associated with the mark; according to the decoded ablation quality level information, differentiating and displaying the corresponding ablation site.

9. The method of claim 8, wherein the ablation mark is implemented by controlling the electric field. The differentiated display is specifically: the ablation sites corresponding to the optimal level, the acceptable level and the suboptimal level are displayed in different colors respectively.

10. The method of claim 1, wherein the ablation mark is implemented by controlling the electric field. The ablation pulse field is a series of high-intensity, narrow-pulse-width pulses.

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