BR102018074440A2 - short temperature-controlled ablation with multiple electrodes - Google Patents

Abstract

the present invention relates to an apparatus that includes a catheter configured to be inserted into an organ of the human body. a plurality of electrodes are implanted in the catheter, and the electrodes are configured to transfer radiofrequency (rf) ablation energy to the organ tissue. the apparatus also includes a power supply configured to simultaneously supply RF ablation energy at a level of up to 100 wa each of the plurality of electrodes, in order to subject the respective sections of the organ tissue in contact with the electrodes.

Description

Descriptive Report of the Invention Patent for SHORT TERM ABLATION TEMPERATURE CONTROLLED WITH MULTIPLE ELECTRODES.

CROSS REFERENCE TO RELATED ORDER

[001] This application claims the benefit of US provisional patent application No. 62 / 529,158, filed on July 6, 2017, hereby incorporated by reference.

FIELD OF THE INVENTION

[002] This invention refers, in general, to surgery and, specifically, to surgery with the use of radiofrequency ablation. BACKGROUND OF THE INVENTION

[003] Radiofrequency (RF) ablation is a treatment modality that kills unwanted tissue by heat. Beginning with the treatment of cardiac arrhythmia in the 1980s, RF ablation found clinical application in several diseases and today it is the treatment of choice for certain types of cardiac arrhythmia and certain cancers. During RF ablation, an electrode is inserted close to the target region under medical imaging guidance. The tissue surrounding the electrode in the target region is destroyed by heat through an electrical RF current.

[004] US patent application No. 2003/0236455, granted to Swanson et al., Describes a probe set for mapping and subjecting pulmonary vein tissue to ablation. The probe set includes an expandable and retractable basket set that has multiple slots. One or more of the grooves carry one or more electrodes adapted to detect electrical activity in the pulmonary vein tissue.

[005] US patent application No. 2014/0066921, issued to Coe et al., Describes balloon catheter neuromodulation systems. The request refers to modulation (for example, rupture, ablation,

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2/31 stimulation) of the nerves by mechanical compression, application of energy or fluid release.

[006] US patent 5,931,835, issued to Mackey, describes a system for releasing radiofrequency energy to multipolar electrode catheters. It is claimed that the energy, voltage or temperature supplied to multiple electrodes can be dynamically controlled.

[007] EP patent application 1,645,234, granted to Buysse et al., Describes an electrosurgical system that employs multiple electrodes. The system employs multiple electrodes to produce large volumes of tissue ablation.

[008] US patent application 2002/0161361, granted to Sherman et al., Describes an RF ablation system that uses electrodes and that has automatic temperature control. A selected number of electrodes are said to have a temperature detection device associated with them to provide a temperature signal indicative of the temperature at the interface between the electrode and the tissue.

[009] US patent application 2001/0020166, granted to Daly et al., Describes a system for simultaneous unipolar ablation of multiple electrodes. The system is established for tissue ablation using unipolar RF energy supplied simultaneously to multiple electrodes.

[0010] U.S. patent 6,319,249, issued to Tollner, describes an ablation catheter with, among others, a plurality of ablation electrodes, at least one power source and switching elements for connecting the electrodes to the power source.

[0011] US patent application No. 2008/0161797, granted to Wang et al., Describes ablation catheter electrodes that have multiple thermal sensors. The electrodes are defined as

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3/31 containing two or more thermal sensors in different positions within the electrode.

[0012] The documents incorporated by reference in the present patent application must be considered an integral part of the application except that, to the extent that any terms are defined in these incorporated documents in a way that conflicts with the definitions made explicitly. or implicitly in this specification, only the definitions in this specification should be considered.

DESCRIPTION SUMMARY

[0013] One embodiment of the present invention provides an apparatus that includes:

[0014] a catheter configured to be inserted into an organ of a human body;

[0015] a plurality of electrodes implanted in the catheter, the electrodes being configured to transfer radiofrequency (RF) ablation energy to the organ tissue; and

[0016] a power supply configured to provide RF ablation energy at a level of up to 100 W simultaneously to each of the plurality of electrodes, in order to subject the respective sections of the organ tissue in contact with the electrodes to ablation .

[0017] In a presented modality, the plurality of electrodes includes up to twelve electrodes, and the power supply is configured to provide up to 1.2 kW of radio frequency power.

[0018] In another revealed mode, the device includes a plurality of temperature sensors, each coupled to measure a respective temperature from one of the plurality of electrodes, and the power supply is configured, when the respective temperature of the one among the plurality of electrodes in contact with

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4/31 one of the tissue sections exceeds a selected maximum temperature, to reduce the power level of the RF ablation energy supplied to one among the plurality of electrodes.

[0019] In yet another revealed mode, the device includes a processor that is coupled to the power supply and that is configured to simultaneously measure a respective impedance of the RF ablation energy for each of the plurality of electrodes, and, when a change in the impedance of one of the plurality of electrodes in contact with one of the tissue sections exceeds a predefined value, interrupting the supply of RF ablation energy from the power supply to the one among the plurality of electrodes.

[0020] The catheter may include a balloon catheter.

Alternatively, the catheter may include a basket catheter.

[0021] In addition, according to one embodiment of the present invention, an apparatus is included which includes:

[0022] a catheter configured to be inserted in an organ of a human body;

[0023] a first electrode and a second electrode positioned on the catheter, the electrodes being configured for transferring radiofrequency (RF) ablation energy to the organ tissue;

[0024] a first temperature sensor coupled to measure a first temperature of the first electrode;

[0025] a second temperature sensor coupled to measure a second temperature of the second electrode;

[0026] a power supply configured to provide RF ablation energy;

[0027] a switch connected to the power supply and configured to direct the RF ablation energy to one of the first and second electrodes; and

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5/31

[0028] a configured processor, while the power supply provides RF ablation energy through the switch to the first electrode, to monitor the first and second temperatures and, responsively to the monitored temperatures, to switch the switch in order to direct the RF ablation energy to one of the first and second electrodes.

[0029] In an alternative mode, the processor is configured by detecting that the first temperature exceeds a predefined ablation temperature threshold while the second temperature does not exceed the ablation temperature threshold, to switch the key so as to direct the RF ablation energy for the second electrode.

[0030] In another alternative modality, the processor is configured to monitor a first time for ablation through the first electrode and a second time for ablation through the second electrode and, in a responsive way to the monitored times, to switch the key in a direct way the RF ablation energy to one of the first and second electrodes. Typically, the processor is configured by detecting that the first ablation time is equal to or exceeds a predefined first time for ablation of the first electrode while the second time for ablation is less than a second predefined time for ablation of the second electrode, to toggle the switch to direct RF ablation energy to the second electrode.

[0031] In yet another alternative embodiment, the first electrode is configured to transfer the RF ablation energy to a first power level, and the second electrode is configured to transfer the RF ablation energy to a second power level, and the power supply is configured to supply power to the electrodes at a level no higher than a maximum of the first and the

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6/31 according to power levels.

[0032] The second catheter can be a balloon catheter.

Alternatively, the catheter can be a basket catheter.

[0033] In addition, according to one embodiment of the present invention, a method is included which includes:

[0034] inserting a catheter in an organ of a human body;

[0035] implant a plurality of electrodes in the catheter, and the electrodes are configured to transfer radiofrequency (RF) ablation energy to the organ tissue; and

[0036] provide a power supply to supply RF ablation energy at a level of up to 100 W simultaneously to each of the plurality of electrodes, in order to subject the respective sections of the organ tissue in contact with the electrodes to ablation .

[0037] In addition, according to one embodiment of the present invention, a method is included which includes:

[0038] inserting a catheter in an organ of a human body;

[0039] implant a first electrode and a second electrode in the catheter, the electrodes being configured to transfer radiofrequency (RF) ablation energy to the organ tissue;

[0040] coupling a first temperature sensor to measure a first temperature of the first electrode;

[0041] coupling a second temperature sensor to measure a second temperature of the second electrode;

[0042] configure a power supply to provide RF ablation energy;

[0043] connect a switch to the power supply and configure the switch to direct the RF ablation energy to one of the first and second electrodes; and

[0044] while the power supply is supplying RF ablation energy through the switch to the first electrode,

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7/31 monitor the first and second temperatures and, responsively to the monitored temperatures, toggle the switch in order to direct the RF ablation energy to one of the first and second electrodes.

[0045] The present disclosure will be better understood from the following detailed description of its modalities, taken in conjunction with the drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 is a schematic illustration of an invasive medical procedure using the device, in accordance with an embodiment of the present invention;

[0047] Figure 2 is a schematic perspective view of a balloon catheter in its inflated configuration, according to an embodiment of the present invention;

[0048] Figure 3 is a schematic view of the balloon catheter implanted in a pulmonary vein, according to an embodiment of the present invention;

[0049] Figure 4 is a schematic view of a plurality of sheets of flexible circuit assemblies, according to an embodiment of the present invention;

[0050] Figure 5 is a schematic perspective view of a partially lifted flexible circuit assembly of the balloon catheter, according to an embodiment of the present invention;

[0051] Figure 6 is a block diagram of the apparatus of Figure 1, according to a first embodiment of the present invention;

[0052] Figure 7 is a flow chart of steps of an algorithm executed in operation of the first modality;

[0053] Figure 8 is a block diagram of the apparatus of Figure 1, according to a second embodiment of the present invention; and [0054] Figure 9 is a flow chart of steps of an algorithm

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8/31 executed in operation of the second modality. DETAILED DESCRIPTION OF THE MODALITIES Overview

[0055] In embodiments of the present invention, a catheter, which has a plurality of electrodes positioned on it, is inserted into an organ, typically the heart, of a human body. The electrodes are configured to transfer radiofrequency (RF) ablation energy to the organ tissue.

[0056] In a first embodiment of the invention, the power supply supplies RF ablation energy at a level of up to 100 W simultaneously to each of the plurality of electrodes, in order to subject the respective sections of the organ tissue to ablation in contact with the electrodes. During this simultaneous ablation, careful monitoring of temperature and impedance at each electrode separately allows the modalities of the present invention to perform multiple tissue ablations at powers up to 100 W on each electrode without adverse effects on the tissue. The high powers allow the time for a total ablation session for multiple ablations to be reduced to times typically no more than 10s.

[0057] In a second embodiment of the invention, the plurality of electrodes comprises a first electrode and a second electrode. A first temperature sensor measures a first temperature of the first electrode, and a second temperature sensor measures a second temperature of the second electrode. A power supply provides RF ablation energy, and a switch is connected to the power supply and is configured to direct RF ablation energy to one of the first and second electrodes. A processor is configured, while the power supply supplies RF ablation energy through the switch to the first electrode, to monitor

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9/31 the first and second temperatures and, in a responsive way to the monitored temperatures, to alternate the switch in order to direct the RF ablation energy to one of the first and second electrodes. The alternation of RF energy between the electrodes, depending on the temperatures of the electrodes, ensures the efficient use of a power supply that may be unable to supply high powers to both electrodes simultaneously, due to the maximum rated power of the power supply. DETAILED DESCRIPTION

[0058] In the following description, similar elements in the drawings are identified by similar numerals, and similar elements are differentiated as necessary, by adding a letter to the identification number.

[0059] Figure 1 is a schematic illustration of an invasive medical procedure using the device 12, according to an embodiment of the present invention. The procedure is performed by a medical professional 14 and, as an example, it is assumed that the procedure in the description later in this document comprises the ablation of a portion of a myocardium 16 from the heart of a human patient 18. However, it is understood that the modalities of the present invention are not merely applicable to that specific procedure and can substantially include any procedure on biological tissue or non-biological materials.

[0060] To perform the ablation, the medical professional 14 inserts a probe 20 into a wrap 21 that was prepositioned in a patient's lumen. Wrap 21 is positioned so that a distal end 22 of probe 20 enters the patient's heart. A balloon catheter 24, which is described in more detail below with reference to Figures 2 to 5, is disposed through a lumen 23 of the

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10/31 probe 20 and exits distal end 22 of probe 20.

[0061] As shown in Figure 1, the device 12 is controlled by a system processor 46, which is located on an operational console 15 of the device. The console 15 comprises controls 49 that are used by the professional 14 to communicate with the processor. During the procedure, processor 46 typically tracks a location and an orientation of the distal end 22 of probe 20, using any method known in the art. For example, processor 46 can use a magnetic tracking method, with magnetic transmitters 25X, 25Y and 25Z external to patient 18 generating signals on one or more coils positioned at the distal end of probe 20. The CARTO® system available with Webster Biosense, 33 Technology Drive, Irvine, CA, 92618, USA, uses this type of tracking method.

[0062] The processor software 46 can be downloaded to the processor in electronic form, over a network, for example. Alternatively or additionally, the software can be supplied on tangible non-transitory media, such as optical, magnetic or electronic storage media. The tracking of the distal end 22 is typically displayed in a three-dimensional representation 60 of the patient's heart 18 on a screen 62.

[0063] In the description of the present invention, it is assumed that processor 46 is formed from any suitable integrated circuits, including, but not limited to, an ASIC (integrated circuit for specific application), an FPGA (array of ports field programmable), an MCU (microcontroller unit) and a CPU.

[0064] To operate the device 12, processor 46 communicates with a bank of modules 50, which has several modules used by the processor to operate the device. Thus, bank 50

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11/31 comprises a temperature module 52, a power supply 54, a switch 57, an irrigation module 55 and an electrocardiograph (ECG) module 56, whose functions are described below. The bench 50 typically comprises other modules, such as a force module for measuring force at the distal end 22 and a tracking module for operating the tracking method used by processor 46. For the sake of simplicity, such other modules are not illustrated in Figure 1. The modules can comprise hardware elements as well as software elements.

[0065] Figure 2 is a schematic view in perspective of the balloon catheter 24 in its inflated configuration, and Figure 3 is a schematic view of the balloon catheter implanted in a pulmonary vein, according to an embodiment of the present invention. In a presented embodiment, where balloon catheter 24 is used to ablate an ostium 11 of a lumen, such as a pulmonary vein 13, as shown in Figure 3, balloon catheter 24 is supported by a tubular drive shaft 70 which has a proximal drive shaft portion 82 and a distal drive shaft end 88. The drive shaft 70 comprises a hollow central tube 74, which allows a support catheter to pass through it and through the end of the drive shaft distal drive 88. The support catheter can be a focal linear catheter or a Lasso 72 catheter, as shown. The Lasso 72 catheter can be inserted into the pulmonary vein (PV) to position the balloon catheter 24 correctly in relation to the ostium before ostium ablation. The distal Lasso portion of catheter 72 is typically formed of shaped memory retaining material, such as nitinol.

[0066] It is understood that the balloon catheter 24 can also be supported by a linear catheter or focal catheter 99 (as shown in dashed lines in Figure 2) in the pulmonary vein or in

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12/31 another part of the heart. The focal catheter 99 may include a force sensor at its distal tip. Distal tips sending adequate force are disclosed in US patent No. 8,357,152, issued on January 22, 2013 to Govari de et al., Entitled CATHETER WITH PRESSURE SENSING, and in US patent application 2011/0130648, Beeckler et al ., filed on November 30, 2009, entitled CATHETER WITH PRESSURE MEASURING TIP, the contents of both being incorporated by reference. Any catheter used in conjunction with the balloon catheter can have characteristics and functions, including, for example, pressure detection, ablation, diagnosis, for example, navigation and rhythm regulation.

[0067] An inflatable balloon 80 of balloon catheter 24 has an outer wall or membrane 26 of a biocompatible material, for example, formed from a plastic, such as polyethylene terephthalate (PET), polyurethane or PEBAX®. The drive shaft 70 and the distal end of the drive shaft 88 define a longitudinal geometric axis 78 of the balloon 80. The balloon 80 is positioned in a flat, non-inflated configuration through lumen 23 of the probe 20 and can be inflated after exiting the end distal 22. Balloon 80 can be inflated and deflated by injection and expulsion of a fluid, such as saline solution through the drive shaft 70. The membrane 26 of balloon 80 is formed with irrigation pores or openings 27 (shown in Figure 5) through which the fluid can exit the interior of the balloon 80 out of the balloon to cool the tissue ablation site in the ostium. While Figure 3 shows the fluid exiting the balloon 80 as a jet stream, it is understood that the fluid can exit the balloon at any desired flow and / or pressure, including a flow in which the fluid is leaking out of the balloon .

[0068] The membrane 26 supports and carries a combined electrode and a temperature sensing element that is

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13/31 constructed as a multi-layer flexible circuit electrode set 84. The flexible circuit electrode set 84 can have many different geometric configurations. In the illustrated embodiment, the flexible circuit electrode assembly 84 has a plurality of radiating sheets or strips 30.

[0069] Figure 4 is a schematic view of a plurality of sheets 30, according to an embodiment of the present invention. The leaves 30 are uniformly distributed around the distal end 88 and the balloon 80. Each leaf has a wider proximal portion that gradually tapers to a narrower distal portion. Figure 4 shows, by way of example, ten radiating sheets 30, but it will be understood that the embodiments of the present invention can have more or less than ten sheets. In one embodiment, mentioned below, there are twelve sheets 30.

[0070] With reference to Figures 2 and 4, each sheet 30 has a proximal tail 31P and a distal tail 31D. The proximal tail 31P is inserted under and attached to the catheter 24 by a proximal ring 28P mounted on the proximal driving shaft portion 82 of the driving shaft 70. The distal tail 31D is inserted under and attached to the catheter 24 by a distal ring (not shown). One or both sets of tails 31D and 31P can be additionally covered by a respective semi-spherical cap, such as the distal cap 28D. One or more contact electrodes 33 on each sheet come in galvanic contact with ostium 11 during an ablation procedure, during which electrical current flows from contact electrodes 33 to ostium 11, as shown in Figure 3. In the description, electrodes 33 are differentiated as needed, by adding a letter to the identification number, so that there are electrodes 33A, 33B, .....

[0071] Figure 5 is a schematic perspective view of a flexible circuit assembly partially raised from the catheter

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14/31 balloon, according to an embodiment of the present invention. For the sake of simplicity, the flexible circuit electrode set 84 is described in relation to one of its sheets 30, as shown in Figure 5, although it is understood that the following description may apply to each sheet of the set. The flexible circuit electrode assembly 84 includes a flexible and resilient sheet substrate 34, constructed of suitable biocompatible materials, for example, polyimide. In some embodiments, the sheet substrate 34 has a higher resistance to heat (or a higher melting temperature) compared to the membrane of the balloon 26. In some embodiments, the substrate 34 is constructed of a thermoset material that has a temperature of decomposition that is approximately 100 ° C, or more, higher than the melting temperature of the membrane of balloon 26. [0072] Substrate 34 is formed with one or more pores or irrigation openings 35 that are in alignment with the openings of irrigation 35 of the balloon element 26 so that the fluid passing through the irrigation openings 35 can pass to the ablation site in the ostium.

[0073] Substrate 34 has a first surface, or outer surface, 36 facing the opposite side of the balloon 26 membrane, and a second surface, or inner surface, 37 facing the balloon 26 membrane. On its outer surface 36 , the substrate 34 supports and transports the contact electrodes 33 adapted for the contact of the tissue with the ostium. On its internal surface 37, substrate 34 supports and carries a wiring electrode 38. Contact electrode 33 provides RF energy, supplied by power supply 54, to the ostium during ablation and is connected to a thermocouple junction (described in more details below) to detect ostium temperature. In the illustrated embodiment, the contact electrode 33 has a longitudinally elongated portion 40 and a plurality

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15/31 of thin transverse linear portions, or fingers, 41 extending generally perpendicularly from each side of the elongated portion 40 between the enlarged proximal and distal ends 42P and 42D, generally uniformly spaced apart. The elongated portion 40 is larger in width and each of the fingers is generally less uniform in width. Consequently, the configuration or trace of the contact electrode 33 resembles a fish bone.

[0074] One or more exclusion zones 47 are formed inside the contact electrode 33, each of them surrounding an irrigation opening 27 formed in the substrate 26. Exclusion zones 47 are empty spaces supposedly formed in the contact electrode 33, as explained in detail later in this document, in order to avoid damage to the contact electrode 33 during the construction of the electrode set 84 in the accommodation of the irrigation openings 27 in their locations and in their function.

[0075] One or more blind conductive pathways 33 are also formed on the contact electrode 48 which are conductive or metallic formations that extend through through holes in the substrate 34 and are configured as electrical conduits that connect the contact electrode 33 on the outer surface 36 and the wiring electrode 38 on the inner surface 37. It is understood that conductive is used here interchangeably with metal in all relevant instances.

[0076] Attached, for example, by a brazing solder 63, to an active brazing block portion 61A of electrode 38 is a pair of wires, for example, a constantan wire 51 and a copper wire

53. The copper wire 53 provides a conductive wire for the fixation electrode 33, and the copper wire 53 and the constantan wire 51 provide a thermocouple whose junction is at the brazing solder 63, so that the

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16/31 solder 63 is also called thermocouple junction 63 in the present invention. Junction 63 acts as a temperature sensor and is also referred to in this document as sensor 63, and the sensors are differentiated as needed by adding a letter to the identification number, so that there are sensors 63A, 63B, .... Thus, for each electrode 33A, 33B, ..., there is a respective temperature sensor 63A, 63B, ..

[0077] The pair of wires 51/53 is passed through a through hole 29 formed in the membrane 26. It is understood that, in other embodiments in the absence of through hole 29, the pair of wires 51/53 can be located between the membrane 26 and substrate 34 and more proximally between membrane 26 and proximal tail 31P until wire pair 51/53 enters the tubular drive shaft 70 through another through hole (not shown) formed in the side wall of the shaft tubular drive closer to the proximal ring 28.

[0078] The electrode assembly of the flexible circuit 84, including the leaves 30 and the tails 31P and 31D, is attached to the membrane of the balloon 26 so that the outer surface 36 of the substrate 34 is exposed and the inner surface 37 of the substrate 34 is fixed to the membrane of the balloon 26, with the spinning electrode 38 and the pair of wires 51/53 sandwiched between the substrate 34 and the membrane of the balloon 26.

First modality

[0079] Figure 6 is a block diagram of an apparatus 12, according to a first embodiment of the present invention. In Figure 6, processor 46, temperature module 52, power supply 54, switch 57 and catheter 24 are illustrated as rectangular blocks, and the block diagram also illustrates detection signals, control signals and power connections between the different elements of the device 12. The switch 57 comprises a plurality of subkeys 59A, ..., 59D, ..., 59N, collectively called

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17/31 subkeys 59. Catheter 24 comprises electrodes 33A, ..., 33D, ... 33N, which are respectively attached to sensors 63A, ..., 63D, ... 63N, and which are also connected to receive power from the power supply via subkeys 59A, ..., 59D, ..., 59N. In the first modality of the apparatus 12 illustrated in Figure 6, all subkeys 59 are constantly closed, so that, when activated, the power supply 54 supplies energy to all the electrodes 33 simultaneously.

[0080] Thus, in the operation of the device 12, and with reference also to Figure 1, the temperature module 52 receives detection signals from each sensor 63 of each electrode 33 and uses the signals to determine a tissue temperature, which is the temperature of the tissue surface in contact with each of the electrodes. The temperature module is configured to calculate the tissue temperature at a fixed rate, assumed in the present invention to be every 33 ms, but other modalities can calculate the tissue temperature at higher or lower rates. The temperature module passes through the tissue temperature values, calculated for each of the electrodes 33, to the processor 46, which, in turn, passes the control signals to the power supply 54.

[0081] The power supply 54 provides RF energy, separately and individually, through the respective subkeys 59, to each electrode 33 of the balloon catheter 24. In some embodiments, the RF energy is supplied via copper wire 53 Alternatively or additionally, RF energy can be supplied to the respective electrodes 33 by another conductor. The energy can be supplied to each electrode in a range from 1 W to 100 W, and the energy can be supplied simultaneously to all the electrodes 33. Thus, in an embodiment of the invention comprising twelve

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18/31 electrodes 33, module 54 can supply 100 W to each electrode, for a total power input to the 1.2 kW catheter.

[0082] To supply these high powers, it must be understood that conducting wires for the electrodes 33, and the substrate 34, provide sufficient insulation in order to avoid any arc of the electrodes.

[0083] In embodiments of the present invention, the power supply can be configured to provide a maximum RF energy for each electrode 33 that can be adjusted within a range of 70 W to 100 W. In some embodiments, the module can be configured to provide additional RF energy for each electrode 33 in a range other than the maximum. In one embodiment, the power variation is additionally from 20W to 60W, and the additional power is typically supplied after the maximum power. The maximum RF energy and the additional RF energy are also referred to in the present invention as first power and second power.

[0084] The power supply also measures an impedance for each electrode 33. The impedance is measured at a predefined rate, assuming in the present invention, to be every 500 ms, but other modalities can measure the impedance at a more low or higher.

[0085] For each electrode 33, the maximum power for the electrode, and the time period in which the power is applied, is selected by the professional 14. The professional can also select power values less than 70 W and corresponding time periods for the application of this reduced power. The actual power delivered by any electrode is determined by the tissue temperature received from temperature module 52 for the electrode, as described below.

[0086] Typically, during an ablation session, the impedance displayed at a given electrode 33 decreases. At

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19/31 modalities of the present invention also check if the impedance presented to each electrode increases from a previous impedance measurement by more than a predefined value which, in the present invention, is assumed to be 7 Ω, although other modalities may use higher or lower impedance values for the preset value. An increase in impedance typically occurs if there is an unwanted change in the tissue being subjected to ablation, such as singed or steam bursts. If, for any given electrode 33, the impedance increases more than the predefined value, the power supply is configured to interrupt the application of RF to the given electrode.

[0087] Despite the powers selected by the professional, the power supply is configured to reduce the power provided by a given electrode, typically between approximately 5% and approximately 95%, if the tissue temperature for the given electrode, received from the reach or exceed a predefined temperature threshold. The predefined temperature threshold is a maximum permissible temperature that is defined by the professional 14, and in the following description the predefined temperature threshold is also called the maximum permissible temperature.

[0088] In one mode, the power for a given electrode, which was originally set at 90 W, is reduced to 50 W after 4s, regardless of the sensor 63 reading. In one embodiment of the present invention, the maximum temperature allowed for all electrodes can be set within a range of 60 ° C to 65 ° C. Typically, exceeding the maximum permissible temperature causes undesirable effects, such as singed, coagulation on an electrode 33 and / or bursts of steam in the tissue being subjected to ablation.

[0089] The irrigation module 58 (Figure 1) determines the speed with which the irrigation fluid is delivered to the balloon catheter 24. In

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20/31 embodiments of the present invention, can be adjusted within the range of 5 to 60 ml / minute.

[0090] Figure 7 is a flowchart of steps of an algorithm performed in operation of the first modality of the device 12. The flowchart steps assume that the block diagram of Figure 6 applies, that is, that all subkeys 59 are constantly closed, so that the power supply supplies power to all electrodes simultaneously 33.

[0091] In a 200 range configuration step, ranges are defined for each of the parameters of the variables mentioned above. The ranges can be individually defined for each electrode 33. Although in one embodiment this is typically the same for all electrodes, this is not necessarily the case, and in other embodiments, the ranges are different for different electrodes.

[0092] In one mode, the ranges are defined as shown in Table I. Typically, for the powers, an operator of the device 12, usually a professional 14, defines only the first power, while the second power is automatically predefined by the processor 46 .

Parameter Banner Maximum power delivered (first power) 50W - 100W Second power 15W - 50W Maximum allowable temperature 50 ° C - 65 ° C Irrigation rate 5 - 60 ml / min First time period (during which the first target power is operational) From 1s to 6s Second time period (during which the second target power is operational) Up to 14s Total time period for power supply (sum of first and second time periods) 1s - 20s

Table I

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[0093] The range adjustment step 200 is implemented before the professional 14 performs an ablation.

[0094] At the beginning of an ablation session, in a step of introducing probe 202, the professional 14 inserts the balloon catheter 24 in a desired location in the myocardium 16, using the tracking system incorporated in the device 12.

[0095] In a selected value step 204, before performing the ablation procedure, the professional 14 selects the values of the parameters shown in Table I to be used in the procedure and uses the controls 49 to supply the values to the system. Alternatively, the professional selects a predetermined set of values for the parameters shown in Table I, typically choosing a recipe that comprises the values of a group of such recipes. The values selected typically depend on the depth of the lesion that you want to form with the procedure. For lesions 1 to 3 mm deep, the inventors found that the values of the parameters provided in Table II show good results. For lesions 4 to 5 mm deep, the inventors found that the values of the parameters provided in Table III show good results.

[0096] It should be understood that the selections made by the professional 14 in step 204 are for each electrode 33 individually. Thus, for twelve electrodes 33, twelve sets of parameters are selected. Although selections may be the same for all 33 electrodes, this is not a requirement. For example, the professional can select parameters according to Table II for some electrodes and according to Table III for other electrodes.

[0097] Furthermore, although the parameters selected for each electrode 33 are typically applied simultaneously to all

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22/31 electrodes, this is also not a requirement. In this way, the parameters can be provided at least partially sequentially and / or in a misaligned way, for example, 2s after the ablation has been initiated for an electrode, the ablation can be initiated for a neighboring electrode.

Lesions 1 to 3 mm deep Parameter Value First target power 90W Second target power Undefined Maximum allowable temperature 60 ° C Irrigation rate 8 ml / min Period of time 4s

Table II:

Lesions 4 to 5 mm deep Parameter Value First target power 90 W Second target power 50 W Maximum allowable temperature 60 ° C Irrigation rate 8 ml / min First time period 4s Second time period 6s

Table III

[0098] Those skilled in the art will be able to determine, for other depths of injury, the necessary values of the parameters within the ranges provided in Table I, without undue experimentation.

[0099] In an initial application stage of RF 206, the professional 14 operates the device 12, with the parameter values selected in step 204, in order to perform the electrode ablations 33.

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23/31

Typically, during ablations, screen 62 displays the values of the parameters shown in Table I to the professional. Screen 62 can also be configured to display to the practitioner, by methods that are well known in the art, the progress of RF delivery to the individual electrodes. The progress display can be graphical, like a simulation of the dimensions of the respective lesions as they are produced by the ablations, and / or alphanumeric.

[00100] During the supply procedure, processor 46 uses the temperature module and power supply to perform various checks on the progress of the procedure, as shown in the flowchart by decision steps 208, 210 and 214.

[00101] Processor 46 operates steps 208 to 222 of the algorithm for each specific electrode 33 individually and separately, measuring the impedance of the given electrode and the tissue temperature provided by the sensor 63 of the electrode. For clarity, in the description below, it is assumed that the ablations of all electrodes are implemented simultaneously, in which case the processor performs steps 206 to 222 simultaneously for all different electrodes. Those skilled in the art will be able to adapt the description, with appropriate modifications, to cases of non-simultaneous ablation.

[00102] In step 208, processor 46 uses power supply 54 to check whether the impedance of a given electrode 33 has increased by more than the predetermined impedance value. If it has increased, the system interrupts the procedure for the given electrode in a termination step 216. If step 208 returns a negative value, the control of the algorithm proceeds to decision step 210.

[00103] In step 210, the processor uses temperature module 52 to verify that the fabric temperature measured for the data

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24/31 electrode, as measured by sensor 63 of the electrode, exceeds or reaches the predefined temperature threshold, that is, the maximum allowable temperature selected in step 204. If decision step 210 returns a positive value, the power supply, in a 218 reduction step, it reduces the energy for the given electrode.

[00104] The energy reduction in step 218 is a function of several parameters:

[00105] A difference in temperature between the maximum allowed temperature T (defined in step 204) and the temperature Tt measured in an instant t,

[00106] a change in the temperatures measured between sequential temperature measurements, that is, Tt-i - Tt,

[00107] a target power P, where if the flowchart is working in the first time period, P is the first target power, and if the flowchart is working in the second time period, P is the second target power, and

[00108] a power Pt measured at time t.

[00109] In one mode, the following equations apply for power reduction:

ΔΡ (Τ) = ^{a (Tt} -T ¹ ~ ^Tt) + ÈgzZil (1)

[00110] where ΔΡ (Τ) is a fractional power change as a function of temperature, and a and b are numerical constants. In a revealed mode a = 10 and b = 1.

ΔΡ (ρ) ^{= ίΕ} ^ (2)

[00111] where ΔΡ (ρ) is a fractional power change as

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25/31 a function of power.

ΔΡ = min (ΔΡ (Τ), ΔΡ (ρ)) (3)

[00112] where min (AP (T), ΔΡ (ρ)) is the minimum of ΔΡ (Τ) and ΔΡ (ρ), and ΔΡ is the fractional change in the power applied in step 218.

[00113] Typically, the energy reduction step 218 is performed repeatedly with decision step 210, until the measured temperature is below the predefined temperature threshold.

[00114] If step 210 returns a negative value, control proceeds to decision step 214.

[00115] In decision step 214, processor 46 checks whether the time until ablation by the given electrode, defined in step 204, has been reached. If so, then the flowchart ends. If the time has not been reached, control proceeds to a continuous ablation step 222, where the processor continues ablation by the given electrode and returns to decision steps 208, 210 and 214. Decision steps 208, 210 and 214 they were presented sequentially in the flowchart for simplicity and clarity. Typically, however, the system uses the power supply to perform the steps in parallel.

Second modality

[00116] Figure 8 is a block diagram of the apparatus 12, according to a second embodiment of the present invention. In addition to the differences described below, the block diagram of the second modality is generically similar to that of the first modality (Figure 6) and the elements indicated by the same reference numbers in both block diagrams are common. In contrast to the first modality, in the second modality of

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26/31 apparatus 12 shown in Figure 6, all subkeys 59 are not constantly closed. Instead, as described in detail below, during operation of the apparatus 12 at any given time, some subkeys 59 are opened and some are closed. Figure 8 illustrates, as an example, subkeys 59A and 59N being opened, while subkey 59D is closed.

[00117] Figure 9 is a flow chart of steps of an algorithm performed in the operation of the second modality of the device 12.

[00118] In contrast to the first mode described above, in which the power supply 54 is capable of simultaneously supplying ablation energy to all electrodes 33, in the second mode described later in this document, the power supply module is limited only to be able to supply ablation energy simultaneously to a subset, i.e., a small number, of electrodes 33, due to a maximum rated power of the power supply.

[00119] In an initial step 250, the professional 14 inserts the balloon catheter 24 in a desired location in the myocardium 16, using the tracking system incorporated in the device 12.

[00120] In an assignment step 254, the professional individually assigns the ablation parameters for each electrode 33, that is, a power to be supplied by each electrode, and a duration time for the supply. Although in some cases these may be the same for each electrode 33, for example 90 W for 4 seconds for each electrode 33, there is no need for this to be the case. For example, electrode 33A can be assigned 80 W for 3 seconds, electrode 33B can be assigned 60 W for 4 seconds, electrode 33C can be assigned 70 W for 3 seconds, and so on.

[00121] In some modalities, the assignment can be determined by the positioning of the catheter 24 (as

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27/31 implemented in step 250) in relation to the tissue that undergoes ablation. For example, if the balloon catheter 24 has been positioned to contact the pulmonary vein ostium 11 (Figure 3), energy and time can be defined according to a measured or assumed thickness of the ostium section in contact with the respective electrodes 33.

[00122] In addition to assigning ablation parameters individually for each ablation electrode, in step 254, a predefined temperature threshold is assigned for the temperature measured by sensors 63. The predefined temperature threshold can be assigned by the professional 14 or alternatively it can be predefined for device 12. The temperature threshold is, as previously stated with reference to the first modality, a maximum allowed temperature for a given electrode 33. As was also stated previously, if the fabric temperature becomes higher than the temperature threshold , the fabric may suffer unwanted effects.

[00123] In an initial ablation step 258, the professional activates the device 12 to begin the ablation. Upon activation, processor 46 divides electrodes 33 into two groups: a first group, here called active electrodes 33, which must be used for ablation, and a second group, here called resting electrodes 33, which must not be used for ablation. Processor 46 can make the selection by closing or opening subkeys 59. In this way, the active electrodes 33 are selected by closing a first set of subkeys 59, so that there is a conductive line from the power supply 54 to the electrodes for these electrodes. The resting electrodes 33 are selected by opening a second set of subkeys 59, so that there is no conductive line from the power supply 54 to the electrodes for these electrodes. The processor stores active electrode identities 33

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28/31 in an active electrode recorder and resting electrode identities 33 in a resting electrode record.

[00124] Processor 46 divides the electrodes into two groups so that the total energy required to be supplied to the active group, as determined according to the ablation parameters assigned in step 254, does not exceed a maximum rated power of the power module 54. For example, if there are twelve electrodes 33, each assigned in step 254 to deliver 50 W, and module 54 has a maximum rated power of 500 W, then the processor can assign up to five electrodes to be in the active group, and the rest, in this case seven or more, to be in the group at rest. Typically, processor 46 assigns the active group to have the largest possible number of electrodes 33, consistent with the restriction that the maximum rated power of power module 54 is not exceeded. In some modalities, the assignment can be done initially at random. Alternatively, practitioner 14 can provide the processor with an indication of how the assignment should be done non-randomly, for example, by providing the processor with an order of priority electrodes 33 to be assigned to the active group.

[00125] In a continuation step 262, processor 46 initiates ablation by activating power supply 54, so that the module supplies energy to each of the electrodes 33 of the active group, that is, to each of the electrodes which has the respective subkeys 59 closed, according to the power levels defined in step 254.

[00126] In a first decision step 264, processor 46 checks whether a given active electrode 33 has completed its designated ablation. For example, if in the assignment step 254 a given electrode is assigned for ablation with a power of 50 W for 4s, the

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29/31 processor checks whether an aggregate time during which the given electrode is 50 W dissipated energy is equal to 4s. If the first decision returns negative, then the processor proceeds to a temperature decision step 268, where the processor checks, using the appropriate sensor 63, whether the given temperature of the active electrode exceeds the temperature threshold defined in step 254 If the threshold is not exceeded, that is, the temperature condition returns negative, the control returns to the first decision step 264.

[00127] Thus, if both the first decision step 264 and the temperature decision step 268 return negative, the processor will iteratively repeat these decisions and continue to check whether a given active electrode has completed its assigned ablation, and whether its temperature, as measured by the sensor, exceeded the temperature threshold.

[00128] Processor 46 simultaneously implements the iterative circuit described above for all active electrodes. The iterative circuit follows a return line 270 from the flowchart.

[00129] For any given active electrode, the iteration is interrupted if the first decision step 264 or the temperature decision step 268 returns positive, as explained in more detail below.

[00130] If the temperature decision step 268 returns positive, that is, if a sensor 63 of an active electrode 33 being verified indicates that the threshold temperature has been exceeded, the control is transferred to a switching step of switch 272. From this Thus, if decision 268 returns positive, the iterative circuit of the active electrode being checked is broken.

[00131] In key switching step 272, processor 46 performs the following actions:

[00132] energy for the active electrode checked before starting the

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30/31 step 272 is interrupted, by switching the switch 57, the subkey 59 feeding the active electrode from a closed state to an open state.

[00133] Using electrode identities in the resting electrode register, the processor selects a resting electrode to be converted into an active electrode. The selection is consistent with the restriction that the maximum rated power of the power module 54, when the new active electrode is operational, is not exceeded.

[00134] The selected resting electrode is activated, thus becoming an active electrode, by switching the switch 57, the subkey 59 feeding the active electrode from a closed state to an open state.

[00135] The processor updates the active electrode record and the resting electrode record accordingly. That is, the electrode identity verified in decision step 268 is transferred from the active electrode register to the resting electrode register, and the identity of the resting electrode selected in the switch toggle step is transferred from the resting electrode register. for active electrode registration.

[00136] When the processor performs the actions described above for step 272, control returns to decision step 264, so that the iterative circuit of decision steps 264, 268 and line 270 is restarted.

[00137] As stated earlier, the iterative circuit can also end if decision step 264 returns positive. In this case, the electrode being checked completes its ablation, and control proceeds to a completed electrode registration step 276. In step 276, the processor transfers the electrode identity verified in decision step 264 of the active electrode registration to a registration

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31/31 ablation completed.

[00138] The flowchart continues until a decision step 280, with the processor checking the completed ablation record to see if all electrodes have completed their ablation. If step 280 returns negative, that is, if there is at least one electrode that has not completed its assigned ablation, the control proceeds to the switch 272 alternation step, described above, with the active electrode verified in condition 264 being turned off, and an available resting electrode is attached.

[00139] If step 280 returns positive, that is, all electrodes have completed their ablation, then the active electrode verified in decision step 264, which is the last operational electrode, is turned off in a final flowchart step 284 and the flowchart ends.

[00140] Although the above description has used a balloon catheter to provide multiple electrodes 33 for respective ablations, it will be understood that the modalities of the present invention are not limited to balloon catheters. Thus, the modalities of the present invention include other catheters, such as basket catheters, Lasso catheters and focal catheters, with multiple electrodes that are used for the respective ablations.

[00141] Thus, it will be recognized that the modalities described above are cited by way of example and that the present invention is not limited to what was particularly shown and described earlier in this document. Rather, the scope of the present invention includes both combinations and subcombination of the various features previously described in this document, as well as variations and modifications to them that would occur to those skilled in the art upon reading the aforementioned description and which are not disclosed in the prior art. .

Claims (26)

1. Device characterized by the fact that it comprises: a catheter configured to be inserted into an organ of a human body; a plurality of electrodes implanted in the catheter, the electrodes being configured to transfer radiofrequency (RF) ablation energy to the organ tissue; and a power supply configured to provide RF ablation energy at a level of up to 100 W simultaneously to each of the plurality of electrodes, in order to subject the respective sections of the organ tissue in contact with the electrodes to ablation. 2. Apparatus according to claim 1, characterized by the fact that the plurality of electrodes comprises up to twelve electrodes and the power supply is configured to supply up to 1.2 kW of radio frequency energy. 3. Apparatus according to claim 1, characterized by the fact that it comprises a plurality of temperature sensors, each coupled to measure a respective temperature from one of the plurality of electrodes, and the power supply being configured, when the respective temperature of the one among the plurality of electrodes in contact with one of the tissue sections exceeds a maximum selected temperature, to reduce the power level of the RF ablation energy supplied to one among the plurality of electrodes. 4. Apparatus according to claim 1, characterized by the fact that it comprises a processor that is coupled to the power supply and that is configured to simultaneously measure a respective impedance for the RF ablation energy for each of the plurality of electrodes , and, when a change in impedance Petition 870180155653, of 11/27/2018, p. 91/109 2/7 of one of the plurality of electrodes in contact with one of the tissue sections exceeds a predefined value, to interrupt the supply of RF ablation energy from the power supply to the one among the plurality of electrodes. 5. Apparatus according to claim 1, characterized by the fact that the catheter comprises a balloon catheter. 6. Apparatus according to claim 1, characterized by the fact that the catheter comprises a catheter with basket. 7. Device characterized by the fact that it comprises: a catheter configured to be inserted into an organ of a human body; a first electrode and a second electrode positioned on the catheter, the electrodes being configured for transferring radiofrequency (RF) ablation energy to the organ tissue; a first temperature sensor coupled to measure a first temperature of the first electrode; a second temperature sensor coupled to measure a second temperature of the second electrode; a power supply configured to provide RF ablation energy; a switch connected to the power supply and configured to direct RF ablation energy to one of the first and second electrodes; and a configured processor, while the power supply provides RF ablation energy through the switch to the first electrode, to monitor the first and second temperatures and, responsively to the monitored temperatures, to switch the switch in order to direct the energy of RF ablation to one of the first and second electrodes. 8. Apparatus according to claim 7, characterized Petition 870180155653, of 11/27/2018, p. 92/109 3/7 by the fact that the processor is configured, by detecting that the first temperature exceeds a predefined ablation temperature threshold, while the second temperature does not exceed the ablation temperature threshold, to toggle the switch to direct the RF ablation energy for the second electrode. 9. Apparatus, according to claim 7, characterized by the fact that the processor is configured to monitor a first time for ablation through the first electrode and a second time for ablation through the second electrode and, responsively to the monitored times, to toggle the switch so as to direct the RF ablation energy to one of the first and second electrodes. 10. Apparatus according to claim 9, characterized by the fact that the processor is configured, upon detecting that the first time for ablation is equal to or exceeds a predefined first time for the ablation of the first electrode while the second time for ablation is shorter than a pre-defined second ablation time for the second electrode, to switch the key to direct RF ablation energy to the second electrode. 11. Apparatus according to claim 7, characterized by the fact that the first electrode is configured to transfer the RF ablation energy at a first power level, and the second electrode is configured to transfer the RF ablation energy at a second power level, and the power supply is configured to supply power to the electrodes at a level no greater than a maximum of the first and second power levels. 12. Apparatus according to claim 7, characterized by the fact that the catheter comprises a catheter of Petition 870180155653, of 11/27/2018, p. 93/109 4/7 balloon. 13. Apparatus according to claim 7, characterized by the fact that the catheter comprises a catheter with basket. 14. Method characterized by the fact that it comprises: inserting a catheter in an organ of a human body; implant a plurality of electrodes in the catheter, and the electrodes are configured to transfer radiofrequency (RF) ablation energy to the organ tissue; and providing a power supply to supply RF ablation energy at a level of up to 100 W simultaneously to each of the plurality of electrodes, in order to subject the respective sections of the organ tissue in contact with the electrodes to ablation. 15. Method, according to claim 14, characterized by the fact that the plurality of electrodes comprises up to twelve electrodes and the power supply is configured to supply up to 1.2 kW of radio frequency energy. 16. Method, according to claim 14, characterized by the fact that it comprises coupling a plurality of temperature sensors to measure the respective temperature of one of the plurality of electrodes and configure the power supply, when the respective temperature of the one among the plurality of electrodes in contact with one of the tissue sections exceeds a selected maximum temperature, to reduce the power level of the RF ablation energy supplied to one among the plurality of electrodes. 17. Method, according to claim 14, characterized by the fact that it simultaneously comprises the measurement of a respective impedance for the RF ablation energy for each of the plurality of electrodes, and, when a Petition 870180155653, of 11/27/2018, p. 94/109 5/7 change in impedance for one of the plurality of electrodes in contact with one of the tissue sections exceeds a predefined value, interrupting the supply of RF ablation energy from the power supply to the one among the plurality of electrodes. 18. Method according to claim 14, characterized in that the catheter comprises a balloon catheter. 19. Method according to claim 14, characterized by the fact that the catheter comprises a basket catheter. 20. Method characterized by the fact that it comprises: inserting a catheter in an organ of a human body; implant a first electrode and a second electrode in the catheter, the electrodes being configured to transfer radiofrequency (RF) ablation energy to the organ tissue; coupling a first temperature sensor to measure a first temperature of the first electrode; coupling a second temperature sensor to measure a second temperature of the second electrode; configure a power supply to provide RF ablation energy; connect a switch to the power supply and set the switch to direct RF ablation energy to one of the first and second electrodes; and while the power supply is supplying RF ablation energy through the switch to the first electrode, monitoring the first and second temperatures and, responsively to the monitored temperatures, switching the switch to direct RF ablation energy to one of the first and second electrodes. Petition 870180155653, of 11/27/2018, p. 95/109 6/7 21. Method according to claim 20, characterized in that it comprises, upon detecting that the first temperature exceeds a predefined ablation temperature threshold while the second temperature does not exceed the ablation temperature threshold, alternating the key in order to direct the RF ablation energy to the second electrode. 22. Method, according to claim 20, characterized by the fact that it comprises monitoring a first time for ablation through the first electrode and a second time for ablation through the second electrode and, responsively to the monitored times, toggle the in order to direct the RF ablation energy to one of the first and second electrodes. 23. Method, according to claim 22, characterized by the fact that it comprises, upon detecting that the first time for ablation is equal to or exceeds a predefined first time for ablation of the first electrode while the second time for ablation is shorter than a second preset time for ablation of the second electrode, toggle the switch so as to direct the RF ablation energy to the second electrode. 24. Method according to claim 20, characterized in that the first electrode is configured to transfer the RF ablation energy at a first power level, and the second electrode is configured to transfer the RF ablation energy at a second power level, and the power supply is configured to supply power to the electrodes at a level no greater than a maximum of the first and second power levels. 25. The method of claim 20, Petition 870180155653, of 11/27/2018, p. 96/109 7/7 characterized by the fact that the catheter comprises a balloon catheter. 26. Method according to claim 20, characterized by the fact that the catheter comprises a basket catheter.