Ablation status determination system

Abstract

The ablation status determination system determines the ablation status of an ablation area formed on the inner wall of the heart. The ablation status determination system (1) includes a first wiring unit having a first electrode (11) that is brought into contact with an inner region of a circular ablation line, a second wiring unit having a second electrode that is brought into contact with an outer region of the circular ablation line, and a control device. The control device includes a measurement unit that measures impedance between the first electrode and the second electrode, and a status determination unit that determines the ablation status of the ablation area based on the measurement result by the measurement unit.

Description

[Technical Field]

[0001] The present disclosure relates to an ablation status determination system for determining the ablation status of an ablation area formed on an inner wall of a heart. [Background technology]

[0002] Conventionally, catheter ablation has been performed to treat atrial fibrillation, which causes arrhythmia, by inserting an ablation catheter into the heart and cauterizing myocardial cells in the atrium. For example, Patent Document 1 discloses a system for performing such catheter ablation.

[0003] When performing catheter ablation, the impedance between the electrode plate attached to the back and the tip of the ablation catheter is measured during the ablation process, and the measured impedance is used as an indicator of the ablation effect, such as whether the ablation was successful or not. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-081217 Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned method for confirming the ablation effect, electrodes are attached to the back outside the heart, but in this case, the impedance between the inside of the heart and the back is large to begin with, making it difficult to accurately determine the ablation state of cardiomyocytes from the change in impedance.

[0006] Therefore, the present disclosure describes an ablation state determination system that can more accurately determine the ablation state of the inner wall of the heart. [Means for solving the problem]

[0007] An ablation condition determination system according to one aspect of the present disclosure is: [1] "An ablation condition determination system for determining the ablation condition of an ablation area formed by ablating the inner wall of the heart along a circular planned ablation line, comprising: a first wiring unit having a first electrode that is brought into contact with an inner region of the inner wall surface of the heart along the circular planned ablation line; a second wiring unit having a second electrode that is brought into contact with an outer region of the inner wall surface of the heart along the circular planned ablation line; and a control device to which the first wiring unit and the second wiring unit are connected, wherein the control device further comprises: a measurement unit that measures impedance between the first electrode and the second electrode while the first electrode is brought into contact with the inner region of the circular planned ablation line and the second electrode is brought into contact with the outer region of the circular planned ablation line; and a condition determination unit that determines the ablation condition of the ablation area based on the measurement result by the measurement unit."

[0008] This ablation state determination system includes a first electrode and a second electrode, each of which is brought into contact with the inner wall of the heart. This allows the ablation state determination system to measure the impedance between positions inside and outside a circular planned ablation line (ablation area) on the inner wall surface of the heart. When cardiac cells are ablated, the impedance of the ablated area changes. Therefore, the impedance between the first electrode and the second electrode differs between a case where the ablation area is properly formed in a circular shape and a case where the ablation area is not properly formed in a circular shape or where the ablation area includes a portion that is not properly ablated due to insufficient ablation. Therefore, the ablation state determination system can more accurately determine the ablation state of the inner wall of the heart based on the impedance between the first electrode and the second electrode, which are brought into contact with the inner wall surface of the heart.

[0009] An ablation state determination system according to another aspect of the present disclosure is [2] "an ablation state determination system for determining the ablation state of an ablation area formed by ablating the inner wall of the heart, comprising: a first wiring unit having a first electrode brought into contact with a portion of the inner wall surface of the heart where the ablation area is formed; a second wiring unit having a second electrode brought into contact with a portion of the inner wall surface of the heart other than the portion where the ablation area is formed; and a control device to which the first wiring unit and the second wiring unit are connected, wherein the control device has: a measuring unit that measures impedance between the first electrode and the second electrode in a state where the first electrode is brought into contact with the portion where the ablation area is formed and the second electrode is brought into contact with a portion other than the portion where the ablation area is formed; and a state determination unit that determines the ablation state of the ablation area based on the measurement result by the measuring unit."

[0010] This ablation state determination system includes a first electrode and a second electrode that are each placed in contact with the inner wall of the heart. This allows the ablation state determination system to measure the impedance between the ablated and non-ablated portions of the inner wall of the heart. When cardiac cells are ablated, the impedance of the ablated area changes. Therefore, a difference occurs in the impedance between the first electrode and the second electrode when the ablation area is properly ablated and when the ablation area is not properly ablated due to insufficient ablation or the like. Therefore, the ablation state determination system can more accurately determine the ablation state of the inner wall of the heart based on the impedance between the first electrode and the second electrode that are placed in contact with the inner wall of the heart.

[0011] The above-mentioned ablation state determination system may be [3] "the ablation state determination system described in [1] or [2] above, wherein the measurement unit measures a first impedance, which is the impedance when an alternating current of a first frequency is applied, and a second impedance, which is the impedance when an alternating current of a second frequency higher than the first frequency is applied, and the state determination unit determines the ablation state of the ablation area based on the difference between the first impedance and the second impedance."

[0012] Here, cardiac cells (cardiomyocytes) exist in extracellular fluid. Cardiac cells before ablation function electrically like a capacitor. For this reason, low-frequency alternating current flows less easily through cardiac cells before ablation, while high-frequency alternating current flows more easily. Therefore, when measuring the impedance between the first electrode and the second electrode, the first impedance is high when an alternating current of the first frequency (low frequency) is applied to cardiac cells before ablation, and the second impedance is low when an alternating current of the second frequency (high frequency) is applied.

[0013] On the other hand, when cardiac cells are ablated, they are destroyed. As a result, the cardiac cells no longer function electrically as capacitors. Therefore, both low-frequency and high-frequency alternating currents flow easily through the ablated cardiac cells. Therefore, when the impedance between the first electrode and the second electrode is measured, both the first impedance when an alternating current of the first frequency (low frequency) is applied and the second impedance when an alternating current of the second frequency (high frequency) is applied are low in the ablated cardiac cells.

[0014] In other words, the ablation state of cardiac cells can be determined based on how closely the first impedance obtained when an alternating current of a first frequency is applied approaches the second impedance obtained when an alternating current of a second frequency is applied.

[0015] As described above, the first impedance when an AC current of a first frequency is applied varies depending on the ablation state of the cells. However, because there is no reference impedance value for when the cells are in the ablation state, it is difficult to determine the ablation state using only the first impedance. Therefore, it is preferable to measure the impedance using the first frequency and the second frequency so that the second impedance when an AC current of a second frequency is used can be used as a reference. In this way, the ablation state determination system described above can determine the ablation state of the ablation area more accurately by determining the ablation state based on the difference between the first impedance and the second impedance.

[0016] The above-mentioned ablation state determination system may be [4] "The ablation state determination system described in the above-mentioned [3], wherein the state determination unit determines that the degree of ablation of the ablation area is higher when the difference between the first impedance and the second impedance is small compared to when the difference is large."

[0017] The higher the degree of ablation of cardiac tissue, the closer the value of the first impedance becomes to the value of the second impedance. By utilizing this characteristic, the ablation state determination system can more appropriately determine the degree of ablation of the ablation area.

[0018] The above-mentioned ablation state determination system may be [5] "the ablation state determination system described in [3] above, wherein the state determination unit determines that the degree of ablation of the ablation area satisfies the predetermined degree of ablation when the difference between the first impedance and the second impedance is equal to or less than a predetermined difference threshold, and determines that the degree of ablation of the ablation area does not satisfy the predetermined degree of ablation when the difference between the first impedance and the second impedance exceeds the difference threshold."

[0019] As the degree of ablation of cardiac tissue increases, the value of the first impedance approaches the value of the second impedance. By utilizing this characteristic, the ablation status determination system can more appropriately determine whether the ablation area is at a predetermined ablation level.

[0020] The above-mentioned cauterization state determination system may be [6] "The cauterization state determination system according to any one of the above-mentioned [1] to [5], further comprising an output unit that outputs the determination result in a manner according to the determination result of the state determination unit."

[0021] In this case, the cauterization state determination system can notify the operator or the like of the determination result of the cauterization state of the cauterization area. [Effects of the Invention]

[0022] According to one aspect of the present disclosure, the ablation state of the inner wall of the heart can be determined with higher accuracy. [Brief explanation of the drawings]

[0023] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of an ablation state determination system according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram showing positions where the first electrode and the second electrode are brought into contact with the inner wall of the left atrium. [Figure 3] FIG. 3 is an image diagram for explaining the impedance when low-frequency and high-frequency alternating currents are passed through the inner wall of the left atrium. [Figure 4] FIG. 4 is an image diagram for explaining the impedance when low-frequency and high-frequency alternating currents are passed through the inner wall of the left atrium. [Figure 5] FIG. 5 is a flowchart showing the process flow of a method for determining whether an ablation area has been ablated using the ablation state determination system. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant description will be omitted.

[0025] The ablation state determination system 1 shown in Fig. 1 is a system that determines (confirms) the ablation state of the inner wall surface of the heart that has been ablated by, for example, catheter ablation. Here, the inner wall of the heart refers to, for example, the inner wall of the atrium. However, the inner wall of the heart is not limited to the inner wall of the atrium, and may be the inner wall of another part of the heart, such as the inner wall of the ventricle.

[0026] Furthermore, the method of catheter ablation (myocardial ablation) is not particularly limited. The ablation state determination system 1 can determine the ablation state (destruction state) of the inner wall surface of the heart that has been ablated (destroyed) by various ablation methods. Examples of ablation methods include a method of ablating cells using high-frequency current output from an RF generator, a cryoablation method of destroying cells by cooling cells to, for example, -40°C, a method of ablating cells by heating a liquid inside a balloon catheter to, for example, 70°C, a laser balloon (JLL) method of ablating cells by irradiating them with a laser from a balloon catheter, and a pulsed field ablation method of destroying cells with an electric field generated by a high-voltage pulse.

[0027] The following describes, as an example, a case where the ablation state of an ablation area A formed on the inner wall W of the left atrium (heart) LA is determined, as shown in Fig. 2. However, the ablation state determination system 1 can also similarly determine the ablation state of an ablation area formed on an inner wall of the heart other than the inner wall W of the left atrium LA.

[0028] In this embodiment, the ablation state determination system 1 determines the ablation state of an annular ablation area A (ablation line) formed on the inner wall W of the left atrium LA so as to surround the connection portion with the pulmonary vein V. This annular ablation area A is formed by connecting a plurality of ablation points formed on the inner wall W of the left atrium LA using an ablation catheter along an annular planned ablation line L. In FIG. 2, the ablated portion of the inner wall W (ablation area A) is hatched.

[0029] 1, the cauterization state determination system 1 includes a first wiring section 10, a second wiring section 20, and a control device 30. The proximal ends of the first wiring section 10 and the second wiring section 20 are connected to the control device 30.

[0030] The first wiring portion 10 includes a first electrode 11 and a first wiring 12. The first electrode 11 is provided at the tip of the first wiring 12. In other words, the first electrode 11 is provided at the tip of the first wiring portion 10. The first wiring 12 is conductive and flexible.

[0031] The second wiring part 20 includes a second electrode 21 and a second wiring 22. The second electrode 21 is provided at the tip of the second wiring 22. In other words, the second electrode 21 is provided at the tip of the second wiring part 20. The second wiring 22 is conductive and flexible.

[0032] The first wiring section 10 and the second wiring section 20 are inserted from the tip side into a blood vessel in the human body (for example, a blood vessel near the base of the thigh). Then, the tip portions of the first wiring section 10 and the second wiring section 20 are made to reach the left atrium through the blood vessel in the trunk.

[0033] In this way, the tip end portions of the first wiring portion 10 and the second wiring portion 20 are thick enough to be inserted into a blood vessel. The first wiring portion 10 and the second wiring portion 20 may be housed in a single catheter (not shown) to facilitate insertion into a blood vessel or the like, for example.

[0034] The first wiring section 10 and the second wiring section 20 may be provided integrally with the ablation catheter. At least one of the first wiring section 10 and the second wiring section 20 may be configured by electrodes and wiring provided on the ablation catheter. In other words, electrodes and wiring provided for performing catheter ablation may be used as the first wiring section 10 and / or the second wiring section 20 of the ablation state determination system 1.

[0035] 2, the first electrode 11 is brought into contact with the inner wall W of the left atrium LA in a region inside the annular ablation line L. That is, the first electrode 11 is brought into contact with the inner wall W of the left atrium LA in a region inside the annular ablation area A. The second electrode 21 is brought into contact with the inner wall W of the left atrium LA in a region outside the annular ablation line L. That is, the second electrode 21 is brought into contact with the inner wall W of the left atrium LA in a region outside the annular ablation area A.

[0036] In this way, when the cauterization area A is appropriately formed in an annular shape, the cauterization area A is located in the middle of the conductive path between the first electrode 11 and the second electrode 21.

[0037] As shown in FIG. 1, the control device 30 includes an ECU (Electronic Control Unit) 31. and an output unit 32. The ECU 31 includes, for example, a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The ECU 31 implements various functions by, for example, loading a program stored in a ROM into a RAM and executing the program loaded into the RAM with a CPU.

[0038] The base end portions of the first wiring portion 10 and the second wiring portion 20 are connected to the ECU 31. The ECU 31 functionally includes a measurement portion 31a and a state determination portion 31b.

[0039] The measuring unit 31a measures the impedance between the first electrode 11 of the first wiring unit 10 and the second electrode 21 of the second wiring unit 20. Here, the measuring unit 31a measures the impedance in a state where the first electrode 11 is in contact with the inner region of the annular ablation area A and the second electrode 21 is in contact with the outer region of the annular ablation area A. The control device 30 includes various devices such as an RF generator so that the measuring unit 31a can measure the impedance.

[0040] In addition, the measuring unit 31a measures a first impedance, which is the impedance when an AC current of a low frequency (first frequency) is applied, and a second impedance, which is the impedance when an AC current of a high frequency (second frequency) higher than the low frequency is applied.

[0041] The measuring unit 31a may measure the first impedance and the second impedance at different times, or may measure them at the same time (simultaneous period).

[0042] Based on the measurement result of the measurement unit 31a, the state determination unit 31b determines the cauterization state of the cauterization area A. Here, the state determination unit 31b determines the cauterization state of the cauterization area A based on the difference between the first impedance and the second impedance.

[0043] Here, we will explain the change in impedance depending on the ablation state of the inner wall W of the left atrium LA. As shown in Figure 3, cardiac cells C (cardiac muscle cells) exist in extracellular fluid F. Before ablation, cardiac cells C function electrically like a capacitor. For this reason, low-frequency alternating current does not easily flow through cardiac cells C before ablation, while high-frequency alternating current flows easily. In other words, low-frequency alternating current has difficulty passing through cells C, so it passes through the extracellular fluid F in the gaps between cells C.

[0044] Therefore, when the impedance between the first electrode 11 and the second electrode 21 is measured, the first impedance is high when a low-frequency alternating current is applied to the cardiac cells C before they are cauterized, and the second impedance is low when a high-frequency alternating current is applied.

[0045] In FIG. 3 and FIG. 4 described later, thick dashed lines indicate paths through which low-frequency alternating current flows, and thick solid lines indicate paths through which high-frequency alternating current flows.

[0046] On the other hand, when cardiac cell C is ablated, cell C is destroyed. Here, the state of the protein in cell C changes. As a result, cardiac cell C no longer functions electrically as a capacitor. Therefore, as shown in Figure 4, both low-frequency and high-frequency alternating currents flow easily through cardiac cell C after ablation. Note that in Figure 4, destroyed cell C is shown using a dashed line.

[0047] Therefore, when the impedance between the first electrode 11 and the second electrode 21 is measured, both the first impedance when a low-frequency alternating current is applied and the second impedance when a high-frequency alternating current is applied are low in the cardiac cells C after ablation.

[0048] In other words, the ablation state (degree of ablation) of cardiac cells C can be determined based on how close the first impedance when a low-frequency alternating current is applied is to the second impedance when a high-frequency alternating current is applied.

[0049] Therefore, when the difference between the first impedance and the second impedance is small, the state determination unit 31b can determine that the degree of ablation of the ablation area A is high compared to when the difference is large. In other words, the state determination unit 31b determines that the degree of ablation is high as the difference is smaller.

[0050] Alternatively, the state determination unit 31b may determine whether the ablation degree of the ablation area A satisfies a predetermined ablation degree, rather than whether the ablation degree of the ablation area A is high or low. Specifically, the state determination unit 31b determines that the ablation degree of the ablation area satisfies the predetermined ablation degree when the difference between the first impedance and the second impedance is equal to or less than a predetermined difference threshold. Alternatively, the state determination unit 31b determines that the ablation degree of the ablation area does not satisfy the predetermined ablation degree when the difference between the first impedance and the second impedance exceeds the difference threshold.

[0051] The measurement unit 31a sets the frequency (low frequency) of the alternating current when measuring the first impedance to a value that results in high impedance for normal cells C before ablation. The measurement unit 31a sets the frequency (high frequency) of the alternating current when measuring the second impedance to a value that results in low impedance both before and after ablation.

[0052] 1, the output unit 32 is a device that presents information to an operator of the ablation state determination system 1. The output unit 32 may be configured to include, for example, a monitor, a speaker, and the like. The output unit 32 outputs the determination result in a manner corresponding to the determination result of the state determination unit 31b. That is, the output unit 32 outputs the determination result using at least one of letters, numbers, illustrations, colors, and sounds so that the operator can recognize the determination result of the state determination unit 31b.

[0053] For example, when the state determination unit 31b determines the cauterization degree, the output unit 32 can output the determination result so that the operator can recognize the determined cauterization degree. Also, when the state determination unit 31b determines whether a predetermined cauterization degree is satisfied, the output unit 32 can output the determination result so that the operator can recognize whether the predetermined cauterization degree is satisfied.

[0054] Next, a description will be given of the processing flow of the ablation determination method for an ablation area using the ablation state determination system 1. For example, the ablation state determination system 1 is operated by an operator such as a doctor. As shown in Fig. 5, the operator inserts the distal ends of the first wiring portion 10 and the second wiring portion 20 into a blood vessel in the human body. Then, the operator inserts the first wiring portion 10 and the second wiring portion 20 until the distal ends of the first wiring portion 10 and the second wiring portion 20 reach the left atrium LA (S101: insertion step).

[0055] When the distal ends of the first wiring portion 10 and the second wiring portion 20 reach the left atrium LA, the operator abuts the first electrode 11 of the first wiring portion 10 and the second electrode 21 of the second wiring portion 20 against the inner wall W of the left atrium LA (S102: electrode abutment step). Here, the operator abuts the first electrode 11 against the inner region of the annular planned ablation line L, and abuts the second electrode 21 against the outer region of the annular planned ablation line L.

[0056] The operator uses the measuring unit 31a of the control device 30 to measure the impedance between the first electrode 11 and the second electrode 21 (S103: measuring step). Here, the first impedance and the second impedance are measured using low-frequency and high-frequency alternating currents.

[0057] The state determination unit 31b of the control device 30 determines the cauterization state of the cauterization area A based on the measurement result of the measurement unit 31a (S104: determination step). The output unit 32 of the control device 30 outputs the determination result of the state determination unit 31b to the operator (S105: output step).

[0058] In the determination step of S104, the operator may determine the cauterization state based on the measurement result of the measurement unit 31 a. In this case, the output unit 32 of the control device 30 may output the measurement result of the measurement unit 31 a so that the operator can check it.

[0059] As described above, the ablation state determination system 1 includes the first electrode 11 and the second electrode 21, each of which is brought into contact with the inner wall W of the left atrium LA. This allows the ablation state determination system 1 to measure impedance between positions inside and outside the annular planned ablation line L (ablation area) on the inner wall W of the left atrium LA.

[0060] When cardiac cells are ablated, the impedance of the ablated area changes. Therefore, a difference occurs in the impedance between the first electrode 11 and the second electrode 21 between a case where the ablation area A is properly formed in an annular shape and a case where the ablation area A is not properly ablated due to discontinuities or where the ablation area A contains areas that are not properly ablated due to insufficient ablation. Therefore, the ablation state determination system 1 can more accurately determine the ablation state of the inner wall W of the left atrium LA based on the impedance between the first electrode 11 and the second electrode 21, which are brought into contact with the inner wall W of the left atrium LA.

[0061] The ablation state determination system 1 determines the ablation state of the ablation area A based on the difference between the first impedance when a low-frequency AC current is applied and the second impedance when a high-frequency AC current is applied. As described above, in cardiac cells after ablation, both the first impedance when a low-frequency (first frequency) AC current is applied and the second impedance when a high-frequency (second frequency) AC current is applied are low. Therefore, the ablation state determination system 1 can more accurately determine the ablation state by determining the ablation state of the ablation area based on the difference between the first impedance and the second impedance.

[0062] As described above, the first impedance changes depending on the ablation state of cardiac cells when a low-frequency alternating current is applied. However, because there is no reference impedance value for when cells are in an ablation state, it is difficult to determine the degree of ablation state using only the first impedance. Therefore, it is preferable to measure impedance using low and high frequencies so that the second impedance when a high-frequency alternating current is used can be used as a reference. This allows the ablation state determination system 1 to determine the ablation state of the ablation area using the difference between the first impedance and the second impedance, thereby more accurately determining the ablation state.

[0063] When the difference between the first impedance and the second impedance is small, the ablation state determination system 1 can determine that the ablation level of the ablation area A is high compared to when the difference is large. Here, the higher the ablation level of the cardiac cells, the closer the value of the first impedance becomes to the value of the second impedance. By utilizing this characteristic, the ablation state determination system 1 can more appropriately determine the ablation level of the ablation area A.

[0064] The ablation state determination system 1 can determine that the predetermined ablation level is met when the difference between the first impedance and the second impedance is equal to or less than a predetermined difference threshold. Furthermore, the ablation state determination system 1 can determine that the predetermined ablation level is not met when the difference between the first impedance and the second impedance exceeds the predetermined difference threshold. Here, the higher the ablation level of cardiac cells, the closer the value of the first impedance becomes to the value of the second impedance. Therefore, by utilizing this characteristic, the ablation state determination system 1 can more appropriately determine whether the ablation area is at the predetermined ablation level.

[0065] The ablation state determination system 1 includes an output unit 32 that outputs the ablation state determination result, thereby enabling the ablation state determination system 1 to notify the operator or the like of the ablation state determination result of the ablation area A.

[0066] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above embodiments. For example, as shown in FIG. 2 , the ablation state determination system 1 measures the impedance between the inner and outer regions of the annular planned ablation line L (ablation area A) using the first electrode 11 and the second electrode 21. Without being limited to this, the ablation state determination system 1 may measure the impedance between the ablation area A and a portion other than the ablation area A using the first electrode 11 and the second electrode 21. Specifically, the ablation state determination system 1 abuts the first electrode 11 against a portion of the inner wall W of the left atrium LA where the ablation area A is formed, and abuts the second electrode 21 against a portion other than the portion where the ablation area A is formed. In this case, the ablation area A does not have to be formed in an annular shape. Even in this case, the ablation state determination system 1 can determine the ablation state of the ablation area A, as in the embodiment. This ablation state determination system 1 can bring the first electrode 11 into contact with an ablation area A formed on the inner wall W of a region other than the left atrium LA of the heart. [Industrial Applicability]

[0067] The ablation state of the inner wall surface of the heart ablated by catheter ablation can be determined with greater accuracy. [Explanation of symbols]

[0068] 1...ablation state determination system, 10...first wiring section, 11...first electrode, 20...second wiring section, 21...second electrode, 30...control device, 31a...measuring section, 31b...state determination section, 32...output section, A...ablation area, L...planned ablation line, LA...left atrium (heart), W...inner wall.

Claims

1. A cauterization state determination system for determining the cauterization state of a cauterization area formed by cauterizing the inner wall of the heart along an annular planned cauterization line, comprising: a first wiring part having a first electrode that is brought into contact with an inner region of the annular planned cauterization line on the inner wall surface of the heart; a second wiring part having a second electrode that is brought into contact with an outer region of the annular planned cauterization line on the inner wall surface of the heart; a control device to which the first wiring part and the second wiring part are respectively connected; wherein the control device includes: a measurement unit that measures the impedance between the first electrode and the second electrode in a state where the first electrode is brought into contact with the inner region of the annular planned cauterization line and the second electrode is brought into contact with the outer region of the annular planned cauterization line; a state determination unit that determines the cauterization state of the cauterization area based on the measurement result by the measurement unit; and the cauterization state determination system having the above components.

2. The measurement unit measures a first impedance that is the impedance when an alternating current of a first frequency is applied, and a second impedance that is the impedance when an alternating current of a second frequency higher than the first frequency is applied, and the state determination unit determines the cauterization state of the cauterization area based on the difference between the first impedance and the second impedance. The cauterization state determination system according to Claim 1.

3. A cauterization state determination system for determining the cauterization state of a cauterization area formed by cauterizing the inner wall of the heart, comprising: a first wiring part having a first electrode that is brought into contact with a portion where the cauterization area is formed on the inner wall surface of the heart; a second wiring part having a second electrode that is brought into contact with a portion other than the portion where the cauterization area is formed on the inner wall surface of the heart; a control device to which the first wiring part and the second wiring part are respectively connected; wherein the control device includes: a measurement unit that measures the impedance between the first electrode and the second electrode in a state where the first electrode is brought into contact with the portion where the cauterization area is formed and the second electrode is brought into contact with a portion other than the portion where the cauterization area is formed; a state determination unit that determines the cauterization state of the cauterization area based on the measurement result by the measurement unit; and the system has the above components. ​ ​ The measurement unit measures a first impedance, which is the impedance when an alternating current of a first frequency is applied, and a second impedance, which is the impedance when an alternating current of a second frequency higher than the first frequency is applied. The state determination unit is a cauterization state determination system that determines the cauterization state of the cauterization area based on the difference between the first impedance and the second impedance.

4. The cauterization state determination system according to claim 2 or 3, wherein the state determination unit determines that the degree of cauterization of the cauterization area is higher when the difference between the first impedance and the second impedance is small than when the difference is large.

5. The state determination unit determines that the degree of cauterization of the cauterization area satisfies a predetermined degree of cauterization when the difference between the first impedance and the second impedance is equal to or less than a predetermined difference threshold. The cauterization state determination system according to claim 2 or 3, wherein the state determination unit determines that the degree of cauterization of the cauterization area does not satisfy the predetermined degree of cauterization when the difference between the first impedance and the second impedance exceeds the difference threshold.

6. The cauterization state determination system according to claim 1 or 3, further comprising an output unit that outputs the determination result in a manner corresponding to the determination result of the state determination unit.

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