A left atrial appendage pulse field ablation occlusion system

Abstract

This invention discloses a left atrial appendage pulse field ablation occlusion system, relating to the field of medical technology. The system includes an occluder and a ring-shaped mapping electrode. The occluder has discharge electrodes bonded to its surface, arranged according to the size of the occluder. The occluder has an umbrella-shaped structure and can be delivered to the left atrial appendage of the left atrium through a sheath in a contracted state. The ring-shaped mapping electrode is inserted through a central channel. Pacing using the discharge electrode does not cause the left atrium to beat at the current frequency, and the discharge electrode does not acquire intracardiac potential. The ring-shaped mapping electrode has a predetermined number of mapping electrodes distributed on its ring surface, used to measure the potential within the left atrial appendage in pairs. Ablation is considered complete when the potential disappears on the ring-shaped mapping electrode. This invention can measure the real-time electrophysiological response inside the atrial appendage while occluding the atrial appendage.

Description

Technical Field

[0001] This application relates to the field of medical technology, and more specifically, to a left atrial appendage pulse field ablation and occlusion system. Background Technology

[0002] Atrial fibrillation (AF) is a serious cardiovascular disease that severely endangers human health. If left untreated, complications such as stroke and heart failure are major causes of death and disability. Radiofrequency ablation is the primary treatment for AF, but it cannot completely prevent left atrial thrombosis. While anticoagulants can prevent most left atrial thrombosis, some patients cannot tolerate long-term anticoagulation therapy or are allergic to anticoagulants.

[0003] Closure of the left atrial appendage can largely prevent left atrial thrombosis, and postoperative treatment with left atrial appendage occlusion only requires monoclonal antibody therapy, making it an effective alternative to oral anticoagulants. Studies have shown that electrical isolation of the left atrial appendage reduces the long-term recurrence rate of atrial fibrillation compared to simple pulmonary vein isolation.

[0004] Therefore, it is essential to invent a left atrial appendage pulse field ablation and occlusion system. Summary of the Invention

[0005] This application provides a left atrial appendage pulse field ablation occlusion system to solve the above-mentioned technical problems.

[0006] This application provides a left atrial appendage pulse field ablation occlusion system, including an occluder and a ring-shaped mapping electrode. The occluder has discharge electrodes bonded to its surface, arranged according to the size of the occluder. The occluder has an umbrella-shaped structure and can be delivered to the left atrial appendage of the left atrium through a sheath in a contracted state. The ring-shaped mapping electrode is inserted through a central channel. Rotating the occluder lever opens the occluder, allowing it to fully open and adhere to the opening of the left atrial appendage. Pacing with the discharge electrode does not cause the left atrium to beat at the current frequency, and the discharge electrode does not acquire intracardiac potential. The ring-shaped mapping electrode has a predetermined number of mapping electrodes distributed on its ring surface, used to measure the potential within the left atrial appendage in pairs. The operating terminal of the left atrial appendage pulse field ablation occlusion system can operate the ring-shaped mapping electrode to move axially, allowing the mapping electrode to map the atrial appendage. When the potential disappears on the ring-shaped mapping electrode, ablation is considered complete.

[0007] Furthermore, the number of the aforementioned discharge electrodes is even; and an even number of the aforementioned calibration electrodes are attached to the aforementioned annular calibration electrode.

[0008] Furthermore, the maximum spacing between the aforementioned discharge electrodes is no greater than the first size threshold.

[0009] Furthermore, the discharge pulse generated by the aforementioned discharge electrode is an alternating asymmetric square wave pulse or a unidirectional asymmetric square wave pulse.

[0010] Furthermore, the aforementioned discharge electrodes are designed to discharge in a pairwise discharge manner.

[0011] Furthermore, the discharge electrodes include odd-numbered electrodes and even-numbered electrodes, wherein the odd-numbered electrodes are of the same polarity and the even-numbered electrodes are of the same polarity.

[0012] Furthermore, the size of the aforementioned annular calibration electrode is greater than the second size threshold; the withstand voltage of the aforementioned calibration electrode is greater than the preset withstand voltage threshold.

[0013] Furthermore, the aforementioned left atrial appendage pulse field ablation occlusion system also includes a catheter, the occluder of which can retract into the catheter, wherein the catheter includes a support component and an annular distal end; the support component is provided with a first magnetic positioning sensor, a second magnetic positioning sensor and a third magnetic positioning sensor.

[0014] Furthermore, the first magnetic positioning sensor and the second magnetic positioning sensor are both located at the far end of the ring, and the third magnetic positioning sensor is located below the support component. Spare discharge electrodes are provided at the locations of the first magnetic positioning sensor, the second magnetic positioning sensor, and the third magnetic positioning sensor.

[0015] Furthermore, the aforementioned backup discharge electrodes include backup odd-numbered electrodes and backup even-numbered electrodes, wherein the total width of the aforementioned backup odd-numbered electrodes is the same as the total width of the aforementioned backup even-numbered electrodes.

[0016] Based on the embodiments provided in this application, by combining an occluder and a ring-shaped mapping electrode, the occluder lever is rotated to open the occluder, allowing it to fully open and adhere to the opening of the left atrial appendage. Pacing is applied using a discharge electrode, which does not cause the left atrium to beat at the current frequency, and the discharge electrode does not acquire intracardiac potential. The operating terminal of the left atrial appendage pulse field ablation occlusion system can operate the aforementioned ring-shaped mapping electrode to move axially, allowing the mapping electrode to map the atrial appendage. When the potential on the aforementioned ring-shaped mapping electrode disappears, the ablation is considered complete. In other words, this invention achieves effective control of the discharge electrode and the mapping electrode by combining an occluder and a ring-shaped mapping electrode; simultaneously, it allows for the measurement of real-time electrophysiological responses within the atrial appendage during occlusion, improving measurement accuracy. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of an optional occluder according to an embodiment of this application;

[0019] Figure 2 This is a schematic diagram of an optional annular calibration electrode according to an embodiment of this application. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0021] Atrial fibrillation (AF) is a common cardiac arrhythmia caused by abnormal electrical signals within the heart. AF is characterized by disordered electrical signals in the myocardial cells of the atria, leading to irregular, rapid, and weak contractions of the atria. This prevents the heart from adequately pumping blood to all parts of the body, resulting in decreased cardiac output. The left atrial appendage is a small, pouch-like structure located in the upper part of the left atrium. It is an auxiliary structure for cardiac contraction and normally does not affect normal heart function. The left atrial appendage is formed by a portion of the atrium protruding outwards; it has an opening between itself and the atrium, commonly called the left atrial appendage mouth, which allows blood to flow into the left atrial appendage and then into the left ventricle.

[0022] When atrial fibrillation occurs, the blood flow within the heart becomes turbulent, easily creating eddies in the left atrial appendage (LAA). This can lead to the formation of blood clots within the LA. When these clots flow out of the LA and travel through the bloodstream to tissues such as the brain, they can cause symptoms such as stroke. Although the primary function of the LA is contraction, research indicates that certain areas of the LA may be related to the occurrence and maintenance of atrial fibrillation. In particular, certain areas of the inner wall of the LA may be one of the starting points for atrial fibrillation. Therefore, some treatments for atrial fibrillation, such as left atrial appendage occlusion and left atrial appendage electrical isolation, aim to reduce the occurrence and duration of atrial fibrillation.

[0023] Furthermore, such as Figure 1 as well as Figure 2 As shown, the left atrial appendage pulse field ablation occlusion system provided in this application includes an occluder ( Figure 1 (shown in the image) and the ring-shaped calibration electrode ( Figure 2 (as shown in the image), where,

[0024] The occluder has discharge electrodes bonded to its surface, and the discharge electrodes are arranged according to the size of the occluder. The occluder has an umbrella-shaped structure and can be delivered to the left atrial appendage of the left atrium through a sheath in the contracted state. A ring-shaped mapping electrode is then inserted through the central channel.

[0025] The occluder is opened by rotating the occluder lever, so that it is fully opened and fits against the opening of the left atrial appendage; the discharge electrode is applied for pacing, which does not cause the left atrium to beat with the current frequency, and the discharge electrode does not receive intracardiac potential.

[0026] A ring-shaped mapping electrode has a predetermined number of mapping electrodes distributed on its ring surface. The mapping electrodes are used to measure the potential in the left atrial appendage in pairs.

[0027] In some preferred embodiments of this application, the preset quantity is 8.

[0028] The left atrial appendage pulse field ablation and occlusion system allows the operation terminal to move the annular mapping electrode axially so that the mapping electrode can map the atrial appendage; when the potential on the annular mapping electrode disappears, the ablation is considered complete.

[0029] In some embodiments of this application, the annular mapping electrode is attached with an even number of electrodes, which measure the potential in the left atrial appendage in pairs. After the ablation endpoint, a bidirectional blockade of the potential is achieved. When pacing with this electrode, the left atrium cannot be driven to beat with the current frequency, and the electrode cannot obtain the potential in the heart chambers.

[0030] Based on the embodiments provided in this application, by combining the occluder and the annular mapping electrode, the occluder lever is rotated to open the occluder, allowing it to fully open and adhere to the opening of the left atrial appendage. Pacing is applied using a discharge electrode, which does not cause the left atrium to beat at the current frequency, and the discharge electrode does not acquire intracardiac potential. The operating terminal of the left atrial appendage pulse field ablation occlusion system can operate the aforementioned annular mapping electrode to move axially, allowing the mapping electrode to map the atrial appendage. When the potential on the aforementioned annular mapping electrode disappears, the ablation is considered complete. In other words, this invention achieves effective control of the discharge electrode and mapping electrode by combining the occluder and the annular mapping electrode; simultaneously, it allows for the measurement of real-time electrophysiological responses within the atrial appendage during occlusion, improving measurement accuracy.

[0031] Furthermore, the number of discharge electrodes is even; an even number of calibration electrodes are attached to the annular calibration electrode.

[0032] Furthermore, the maximum spacing between the discharge electrodes is no greater than the first size threshold.

[0033] In some embodiments of this application, the first size threshold may include, but is not limited to, 2 cm, 3 cm, etc. It should be understood that electric field strength analysis of the electrodes reveals that the electric field strength is maximum at the electrode surface and gradually decreases outwards. Simultaneously, the field strength gradually decreases from the electrode towards the center. To ensure sufficient field strength at depth and effective electric field strength in the center of the electrode, it is necessary to analyze the electrode spacing and area to determine optimal parameter values. This is because excessively large spacing cannot form a continuous ablation band, while excessively small spacing leads to concentrated field strength and ionization, and excessively small electrode diameter also leads to concentrated field strength and ionization.

[0034] Furthermore, the discharge pulse generated by the discharge electrode adopts either an alternating asymmetric square wave pulse or a unidirectional asymmetric square wave pulse.

[0035] In some embodiments of this application, pulses are released during the cardiac refractory period, with intervals between pulses, allowing blood perfusion to remove local heat. Bioheat Transfer can be selected from the heat conduction module; bioheat transfer is commonly used in simulating conduction, convection, and radiation in biomaterials. Human organs and tissues constantly exchange energy, and this is a typical example of small-temperature-difference heat transfer. To simulate the changes in the intracardiac environment during ablation, the bioheat transfer equation proposed by Pennes can be applied, as follows:

[0036]

[0037] Q pref =ρ b ×ω b ×C p,b (T b -T);

[0038] Where × represents a multiplication sign. The sign of the partial derivative. Represents the vector differential operator; ρ is the tissue density, unit: kg / m³ 3 c represents the specific heat capacity of the tissue, in J / kg·K; T represents the temperature, in K (Kelvin). The change in temperature is represented by t; time is represented by k; thermal conductivity is represented by W / m·K; Q perf For blood perfusion convective cooling, unit: J; Q e For electromagnetic coupling physical field heat; Q met Heat generated by tissue metabolism, unit: J; ρ b Blood density; ω b Blood flow velocity, unit: m / s; C p,b Specific heat capacity of blood, unit: J / kg·K; T b Blood temperature, unit: K.

[0039] Based on the above paragraphs, it should be understood that the voltage setting corresponding to the electrodes directly affects the size of the ablation range; a larger voltage value results in a larger ablation range, and vice versa. A thermal damage calculation model can be used to simulate the internal environment of human tissue during pulsed field ablation. For example, the Arrhenius equation can be used to estimate the absorbed energy. The formula is:

[0040]

[0041] Where k is the reaction rate constant at temperature T; E a The activation energy is generally considered to be constant and independent of temperature, and its unit is J·mol⁻¹. -1 T is absolute temperature, in K; R is the molar gas constant, in J·mol⁻¹. -1 C is the natural logarithm of the frequency factor.

[0042] Furthermore, based on the Kalman filter algorithm, a preliminary filtering of several mapping signals detected by a predetermined number of mapping electrodes distributed on the ring mapping electrodes can be performed; the filtering result is input into the potential response equation to obtain the potential state in the left atrial appendage; wherein, the potential response equation can be:

[0043] X n,n =X n,n-1 +K n ×(Z n -X n,n-1 );

[0044]

[0045] P n,n = (1-K) n )×P n,n-1 ;

[0046] Where × represents multiplication, and n represents the current time; X n,n X represents the estimated system state at the current moment; n,n-1 K represents the estimated system state at the previous moment. n Z represents the Kalman gain; n R represents the noise covariance; P represents the measurement uncertainty; n,n P represents the variance of the current state estimate uncertainty; n,n-1 This indicates the uncertainty in the previous moment's estimation.

[0047] Based on the embodiments provided in this application, a number of mapping signals detected by a preset number of mapping electrodes distributed on the annular mapping electrodes are used as the judgment conditions for the parameters of the Kalman filter model to complete the pre-process filtering of the potential signal data, thereby achieving high-precision detection of the potential state in the left atrial appendage.

[0048] Furthermore, the discharge electrodes are designed to discharge in pairs.

[0049] Furthermore, the discharge electrodes include odd-numbered electrodes and even-numbered electrodes, wherein the odd-numbered electrodes are of the same polarity and the even-numbered electrodes are of the same polarity.

[0050] Furthermore, the size of the annular calibration electrode is greater than the second size threshold; the calibration electrode withstand voltage is greater than the preset withstand voltage threshold.

[0051] In some embodiments of this application, the second size threshold may include, but is not limited to, 3 cm, 4 cm, etc.

[0052] Furthermore, the left atrial appendage pulsed field ablation occlusion system also includes a catheter, and the occluder can retract into the catheter, wherein...

[0053] The catheter includes a support component and an annular distal end; the support component is equipped with a first magnetic positioning sensor, a second magnetic positioning sensor and a third magnetic positioning sensor.

[0054] Furthermore, the first and second magnetic positioning sensors are both located at the far end of the ring, and the third magnetic positioning sensor is located below the support component. Spare discharge electrodes are provided at the locations of the first, second, and third magnetic positioning sensors.

[0055] Furthermore, the backup discharge electrode includes backup odd-numbered electrodes and backup even-numbered electrodes, wherein the total width of the backup odd-numbered electrodes is the same as the total width of the backup even-numbered electrodes.

[0056] In some embodiments of this application, the electric field intensity distribution at the distal end of the ring and below the support component is more uniform, reducing the excessive concentration of high voltage pulse energy on even-numbered electrodes during high voltage pulse ablation, thereby improving the safety of the left atrial appendage pulse field ablation occlusion system.

[0057] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A left atrial appendage pulse field ablation and occlusion system, characterized in that, Includes an occluder and a ring-shaped mapping electrode, among which, The occluder has discharge electrodes bonded to its surface, and the discharge electrodes are arranged according to the size of the occluder; the occluder has an umbrella-shaped structure, and the occluder can be delivered to the left atrial appendage of the left atrium through a sheath in a contracted state; the central channel of the occluder can be used to deliver the annular mapping electrode. The occluder is opened by rotating the occluder lever, so that the occluder is fully opened and fits against the opening of the left atrial appendage; the discharge electrode is used for pacing, but it does not cause the left atrium to beat with the current frequency, and the discharge electrode does not receive intracardiac potential. The annular mapping electrode has a predetermined number of mapping electrodes distributed on its annular surface. The mapping electrodes are used to measure the potential in the left atrial appendage in pairs. The operating terminal of the left atrial appendage pulse field ablation and occlusion system can operate the annular mapping electrode to move axially so that the mapping electrode can map the atrial appendage; when the potential on the annular mapping electrode disappears, the ablation is determined to be complete. The left atrial appendage pulsed field ablation occlusion system also includes a catheter, and the occluder is retractable within the catheter. The catheter includes a support component and an annular distal end; the support component is provided with a first magnetic positioning sensor, a second magnetic positioning sensor and a third magnetic positioning sensor; The first magnetic positioning sensor and the second magnetic positioning sensor are both located at the far end of the ring, and the third magnetic positioning sensor is located below the support component. Spare discharge electrodes are provided at the locations of the first magnetic positioning sensor, the second magnetic positioning sensor, and the third magnetic positioning sensor. The backup discharge electrode includes backup odd-numbered electrodes and backup even-numbered electrodes, wherein the total width of the backup odd-numbered electrodes is the same as the total width of the backup even-numbered electrodes.

2. The left atrial appendage pulse field ablation and occlusion system according to claim 1, characterized in that, The number of discharge electrodes is even; an even number of the calibration electrodes are attached to the annular calibration electrode.

3. The left atrial appendage pulse field ablation and occlusion system according to claim 2, characterized in that, The maximum dimension of the spacing between the discharge electrodes is not greater than the first dimension threshold.

4. The left atrial appendage pulse field ablation and occlusion system according to claim 1, characterized in that, The discharge pulse generated by the discharge electrode is either an alternating asymmetric square wave pulse or a unidirectional asymmetric square wave pulse.

5. The left atrial appendage pulse field ablation and occlusion system according to claim 1, characterized in that, The discharge electrodes discharge by discharging in pairs between each other.

6. The left atrial appendage pulse field ablation and occlusion system according to claim 1, characterized in that, The discharge electrode includes an odd number of electrodes and an even number of electrodes, wherein the odd number of electrodes are of the same polarity and the even number of electrodes are of the same polarity.

7. The left atrial appendage pulse field ablation and occlusion system according to claim 1, characterized in that, The size of the annular calibration electrode is greater than the second size threshold; the pressure resistance of the calibration electrode is greater than the preset pressure resistance threshold.

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