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BR-112025005915-B1 - PULSED FIELD ABLATION GENERATOR, DEVICE AND METHOD

BR112025005915B1BR 112025005915 B1BR112025005915 B1BR 112025005915B1BR-112025005915-B1

Abstract

PULSED FIELD ABLATION DEVICE AND METHOD. Ablation device and method for pulsed field ablation, wherein the device comprises a catheter including an expandable basket, an electrode array formed in the expandable basket, and a pulse generator suitable for generating electrical pulses, wherein the pulse generator is electrically connected to the electrode array. The expandable basket is formed by a braided mesh of filaments, wherein the filaments are made of non-conductive material, wherein at least a portion of the filaments comprises a lumen, and wherein the lumen comprises molten material, wherein the filaments further include electrodes and conductive wires. The conductive wires conduct, at least partially, into the lumen of the filaments and are electrically connected to the electrodes.

Inventors

  • Vojtech NEDVED
  • Jiri Dasek
  • Martin Hanuliak
  • Ahmad Hijazi

Assignees

  • BTL MEDICAL DEVELOPMENT A.S

Dates

Publication Date
20260310
Application Date
20231004
Priority Date
20221005

Claims (20)

  1. 1. Generator (103) for an ablation device (101), wherein the generator (103) is characterized in that it is configured to generate electrical pulses with an amplitude of 100 V to 5000 V and coupled to at least one electrode (109), wherein the generator (103) comprises: a power supply unit (3200) coupled to a current source (3202) and configured to transfer a current from the current source (3202) to a DC current at an output of the power supply unit (3200); a capacitor unit (3203) coupled to the output of the power supply unit (3200), having a first capacitance and including at least one capacitor; a switching unit (3204) comprising at least one switch (3205) coupled to at least one electrode (109); a DC/DC converter unit (3206) coupled between the capacitor unit (3203) and the switching unit (3204), the DC/DC converter unit (3206) comprising an output capacitor (3213) having a second capacitance; wherein the second capacitance is less than the first capacitance; and wherein the DC/DC converter unit is configured to discharge the output capacitor and electrically disconnect the generator from the electrode.
  2. 2. Generator (103), according to claim 1, characterized in that the first capacitance is from 80 μF to 1000 μF and the second capacitance is from 2 μF to 50 μF.
  3. 3. Generator (103), according to any of the preceding claims, characterized in that the output capacitor (3213) is at an output of the DC/DC converter unit (3206).
  4. 4. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) includes a resistor configured to discharge the output capacitor (3213) and electrically disconnect the generator (103) from the electrode (109).
  5. 5. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) includes either a thyristor or a contactor, wherein the thyristor or the contactor is configured to short-circuit the output capacitor (3213).
  6. 6. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) is configured to discharge the output capacitor (3213) and to electrically disconnect the generator (103) from the electrode (109) in less than 50 ms.
  7. 7. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) includes a DC/DC converter without feedback.
  8. 8. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) is configured to convert the first capacitance into a second capacitance that is lower than the first capacitance.
  9. 9. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) is configured to limit leakage currents from the power supply unit (3200) to the electrode (109) to less than 10 μA.
  10. 10. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) includes two windings and a series of resonant converters.
  11. 11. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) has a conversion ratio of 1:1 to 1:6.
  12. 12. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) has an output voltage of 250 V to 2000 V.
  13. 13. Generator (103), according to any of the preceding claims, characterized in that the DC/DC converter unit (3206) has an output voltage of 500 V to 3000 V.
  14. 14. Ablation device (101), characterized in that it comprises the generator (103) as defined in any of the preceding claims.
  15. 15. Ablation device (101), according to claim 14, characterized in that it comprises electrical control circuits (115) configured to receive and evaluate data comprising at least one measured parameter of the ablation device (101), and further configured to activate the DC/DC converter unit (3206) to electrically disconnect the generator (103) from the electrode (109) when at least one of the measured parameters is outside predetermined limits.
  16. 16. Ablation device (101), according to claim 15, characterized in that the measured parameter is one of a temperature, an impedance, a current or a voltage.
  17. 17. A method for controlling an ablation device (101) for pulsed field ablation, wherein the method is characterized in that it comprises: providing a generator (103), as defined in claim 1, and at least one electrode (109) coupled to the generator (103), wherein the DC/DC converter unit (3206) of the generator (103) further comprises an output capacitor emergency system (3214); providing electrical control circuits (115) coupled to the output capacitor emergency system (3214) and to at least one other part of the ablation device (101); receiving data from the electrical control circuits (115), wherein the data comprise at least one measured parameter of at least one other part of the ablation device (101); evaluating the data with the electrical control circuits (115); activating the output capacitor emergency system (3214); and discharge the output capacitor (3213) and electrically disconnect the generator (103) from the electrode (109) when the measured parameter is outside predetermined limits.
  18. 18. Method according to claim 17, wherein the method is characterized in that it further comprises the step of: providing a resistor in the DC/DC converter unit (3206); and discharging the output capacitor (3213) to the safety discharge resistor.
  19. 19. Method, according to any one of claims 17 to 18, wherein the method is characterized in that it further comprises the step of: providing at least one thyristor or contactor in the DC/DC converter unit (3206); and short-circuiting the output capacitor by means of one thyristor or contactor.
  20. 20. A method according to any one of claims 17 to 19, characterized in that the measured parameter is one of a temperature, an impedance, a current or a voltage.

Description

DESCRIPTION FIELD OF THE INVENTION [001] This invention relates to ablation devices and methods, specifically pulsed field ablation devices and methods of a target tissue by pulsed electric fields, where one of the main principles of ablation may be an irreversible electroporation of cell membranes. BACKGROUND OF THE INVENTION [002] Atrial fibrillation is the most common persistent cardiac arrhythmia, affecting 10% of the population over 60 years of age. In addition to pharmacological treatment, the therapy instituted to improve the symptoms of the disease and reduce mortality is called catheter ablation. [003] Catheter ablation involves the subcutaneous advancement of one or more flexible catheters into the patient's blood vessels, in the case of cardiac ablation usually into a femoral vein, an internal jugular vein, or a subclavian vein. The catheters are then advanced toward the target treatment site or into the heart. [004] The main means of ablation therapy for cardiac arrhythmias is to directly eliminate the pro-arrhythmogenic substrate, destroying it or preventing the propagation of the non-physiological action potential by linear or circular isolation. Both approaches basically require the formation of a lesion through which the myocardial action potential does not spread. By applying energy, a small part of the myocardium is locally destroyed and transformed into non-myocardial connective tissue by natural physiological processes within a few weeks. [005] Common ablation methods known in prior art are based on the thermal destruction of tissue by high or low temperatures. Such methods include, for example, heating a target tissue by radiofrequency (RF) or laser field, or freezing the tissue by cryoablation. These methods cause necrosis of the target tissue, which can add risk to the procedure. [006] Recently, methods and devices that use electric fields for ablation have been used. The aim of these methods is to cause tissue destruction by inducing irreversible electroporation of cell membranes instead of destruction by high or low temperatures, and thus reduce the disadvantages and risks of ablation procedures based primarily on thermal damage, however there are still disadvantages that need to be resolved. [007] Common designs of such devices may be a distally tipped catheter with one or more electrodes. The catheter may have, for example, an active electrode at the tip. An indifferent electrode may be placed, for example, on a patient's skin. Ablation of the target treatment site with such a device must be done point by point, which increases the duration and complexity of the procedure. [008] Another example of an anterior device is a catheter with electrodes placed in a row on the distal end of a single catheter body. The distal end of such a catheter is placed near the target treatment site and unfolded (bent) into a specific shape near the target treatment site. With such a shape, more than one electrode can be used for therapy and less movement of the distal tip is required, but implantation of the catheter in the correct shape, proper positioning, and further manipulation with such a catheter can be very difficult. An indifferent electrode can also be placed on the patient's skin, or ablation can be performed bipolarly between specific electrodes placed on the distal end of the catheter. [009] Devices with catheter end baskets comprising simple rods with electrodes are also known from the prior art. Such a device can ensure easier implantation and positioning at the target site. Given that there are usually more electrodes placed on the catheter end, ablation can again be monopolar with an indifferent electrode, for example, placed on the patient's skin, or bipolar between specific electrodes on the catheter end. A disadvantage of this solution is the limited number of supports, meaning a limited number of electrodes creating a specific circular pattern in space. This disadvantage is caused by the need for mechanical stability of the specific rods to be able to maintain a stable basket shape. This means that to be sufficiently rigid, the supports need to maintain specific dimensions. The number of supports used is then limited by the size of the catheter. Another disadvantage of this solution is that such a construction cannot fully guarantee a mutual distance between the supports in the implanted configuration, meaning that the distance between the electrodes cannot be guaranteed either. This means that the device may need to be repositioned several times to ensure adequate ablation, which prolongs the duration of the procedure. [0010] The quality and safety of ablation need to be increased, on the one hand, while the risks to patients and the duration of therapy need to be reduced, on the other hand. There is therefore a need for improved ablation devices and methods that are gentler and safer for the patient, with reduced complexity and greater quality and reliability of the method and