Methods, systems, and devices for perforating tissue structures

Abstract

The described systems, devices, and methods relate to a system comprising: an electrosurgical interface electrically coupled to a generator; an energy delivery element electrically coupled to the electrosurgical interface, the energy delivery element configured to receive energy from the generator to form a perforation in tissue of the patient; and a return electrode electrically coupled to the patient and the generator.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 435,659, filed on December 28, 2022, entitled “METHODS, SYSTEMS, AND APPARATUSES FOR PERFORATING TISSUE STRUCTURES,” and U.S. Provisional Patent Application No. 63 / 586,940, filed on September 29, 2023, entitled “METHODS, SYSTEMS, AND APPARATUSES FOR PERFORATING TISSUE STRUCTURES,” the disclosure of each of which is incorporated herein by reference. Technical Field

[0003] The embodiments described herein relate generally to medical devices for electrical energy delivery, and more particularly to systems, apparatuses, and methods for perforating and traversing tissue structures, including, for example, performing transseptal punctures during cardiac interventional procedures. Background Art

[0004] In many medical procedures, it may be necessary to puncture a tissue structure to access a treatment site or to establish a pathway or connection between different anatomical structures. For example, in cardiac interventional procedures, a needle, catheter, or guidewire is often used to puncture the atrial septum to access the left side of the heart, for example, to evaluate or treat cardiac abnormalities. In some cases, the guidewire or catheter can be equipped with an energy delivery device that can deliver energy, such as radiofrequency (RF) energy, to a tissue structure (such as the septum) to perforate it.

[0005] While existing systems capable of perforating and traversing tissue structures exist, these systems suffer from various drawbacks. For example, they can cause unnecessary damage to other areas of the heart due to unintended perforations or lead to charring or thrombosis due to high operating temperatures. These systems can also involve complex connections between the catheter, guidewire, and / or other energy delivery components and the electrosurgical generator. The costs associated with manufacturing many of these systems are also high. Consequently, there is room for further improvement in these systems. Summary of the Invention

[0006] In one embodiment, the guidewire includes a conductive distal tip configured to deliver radio frequency (RF) energy to a subject's septum to form a perforation through the septum. The guidewire includes a conductive core coupled to the distal tip, the conductive core configured to conduct RF energy to the distal tip. The guidewire includes a conductive outer portion disposed near the distal tip, the conductive outer portion configured to be coupled to the distal tip via the conductive core. The guidewire includes an insulating collar disposed between the distal tip and the conductive outer portion. The guidewire is configured to extend a first distance distally from the insulating shaft to expose the distal tip to allow the distal tip to deliver RF energy and form a perforation. The guidewire is further configured to extend a second distance distally from the insulating shaft greater than the first distance to expose the distal tip and at least a portion of the conductive outer portion to increase the exposed surface area of ​​the conductive portion of the guidewire, thereby reducing the current density along the conductive portion.

[0007] In one embodiment, a device includes an insulating shaft comprising a proximal end and a distal end and defining a lumen through which the guidewire is inserted. The device includes a guidewire configured to be slidably disposed within the lumen, the guidewire configured to be advanced distally relative to the insulating shaft to expose the distal tip of the guidewire, the distal tip of the guidewire being configured to deliver radiofrequency (RF) energy to a subject's septum to form a perforation through the septum when exposed. The device includes an electrosurgical interface coupled to the proximal end of the insulating shaft and a generator, the electrosurgical interface including a passage aligned with the lumen of the insulating shaft so that the guidewire can extend through the passage and the lumen of the insulating shaft, the electrosurgical interface being configured to establish electrical coupling between the generator and the guidewire and maintain electrical coupling when the guidewire is advanced distally toward the distal end of the insulating shaft. The device includes an actuator configured to, in response to being actuated when the distal tip is exposed, send a signal to the generator so that the generator generates a voltage output and delivers the voltage output to the guidewire via electrical coupling so that the distal tip delivers RF energy to form a perforation.

[0008] In one embodiment, a system includes a generator and an electrosurgical device. The electrosurgical device includes a guide wire configured to deliver radio frequency (RF) energy to a subject's septum and perforate the septum. The electrosurgical device includes an electrosurgical interface configured to be coupled to the generator. The electrosurgical interface includes a passage configured to slidably receive the guide wire so that the guide wire and the electrosurgical interface can move relative to each other. The electrosurgical interface is configured to establish an electrical coupling between the guide wire and the generator and maintain the electrical coupling when the guide wire moves relative to the electrosurgical interface. The generator is configured to generate a voltage output in response to receiving an activation signal and deliver the voltage output to the guide wire via the electrical coupling and monitor characteristics associated with the electrosurgical device and modulate the voltage output based on the characteristics.

[0009] In one embodiment, a method includes extending a guide wire deployed in an insulating sheath a first distance distally toward the distal end of the insulating sheath, the guide wire and the insulating sheath being deployed near a tissue wall. The method includes deploying the distal tip of the guide wire against the tissue wall. The method includes delivering radiofrequency (RF) energy to the tissue wall via the distal tip after deploying the distal tip of the guide wire against the tissue wall. The method includes further extending the guide wire distally to form a perforation through the tissue wall when delivering the RF energy. The method includes: in response to extending the guide wire a second distance distally toward the distal end of the insulating sheath, exposing at least a portion of the conductive outer portion of the guide wire, thereby increasing the exposed conductive surface area of ​​the guide wire after forming the perforation.

[0010] In one embodiment, an energy delivery element is configured to perforate biological tissue. The energy delivery element includes a lead having a distal tip including a first conductive region, a first insulating region disposed proximate to the conductive tip, and a second conductive region disposed proximate to the first insulating region. When the energy delivery device is energized by a generator and at least partially enclosed in an insulating tube, the energy delivery device exhibits a current density that is a function of displacement relative to a distal end of the insulating tube.

[0011] When the distal tip including the first conductive region extends less than 10 mm beyond the end of the insulating tube, wherein the current density is greater than 45 A / cm 2 And less than 250A / cm 2 When the distal conductive tip extends 10 mm beyond the end of the insulating tube, the current density associated with the first conductive region is less than 60 A / cm2 and the current density associated with the second conductive region is less than 60 A / cm2. When the distal conductive tip extends 20 mm beyond the end of the insulating tube, the current density distributed from the first conductive region is less than 25 A / cm2 and the current density distributed from the second conductive region is less than 25 A / cm2. 2 .

[0012] In one embodiment, an electrosurgical interface includes a housing defining a lumen and including a conductive element, the conductive element and the lumen being sized to slidably receive an energy delivery element. The electrosurgical interface includes a powered conductor connected to the conductive element and an actuator for modulating energy delivered by the powered conductor. When the actuator is in an energized state, radio frequency (RF) energy is delivered to the energy delivery element via the conductive element. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 is a schematic diagram of an electrosurgical system according to an embodiment.

[0014] Figure 2 is a schematic diagram of an electrosurgical system showing components positioned relative to a patient, according to an embodiment.

[0015] Figures 3A-3C An interface for transmitting electrical energy from an electrosurgical generator to an energy delivery element is schematically depicted, according to an embodiment.

[0016] Figure 4 An example of an electrosurgical device according to an embodiment is depicted.

[0017] Figure 5A Provided Figure 4 A top view of an electrosurgical interface of an electrosurgical device. Figure 5B A cross-sectional view of an electrosurgical interface is provided with a portion of the outer housing removed to illustrate internal components of the electrosurgical interface. Figure 5C Depicts Figure 4 A side cross-sectional view of an electrosurgical device showing internal components of an electrosurgical interface.

[0018] Figure 6A Depicted is a top view of another example of an electrosurgical interface of an electrosurgical device according to an embodiment. Figure 6B Depicts Figure 6A Side view of the electrosurgical interface. Figure 6C Depicts Figure 6A A top view of an electrosurgical interface showing the internal components of the electrosurgical interface.

[0019] Figure 7A Depicted is a top view of another example of an electrosurgical interface of an electrosurgical device according to an embodiment. Figure 7B Depicts Figure 7A A top view of an electrosurgical interface showing the internal components of the electrosurgical interface. Figure 7C Depicted is a top view of an electrosurgical device showing an arrangement of the electrosurgical device according to an embodiment.

[0020] Figure 8A An example of a guidewire for an electrosurgical device is depicted, according to an embodiment. Figure 8B and Figure 8C The diagram shows a Figure 8A The operation of the guide wire passing through the tissue structure.

[0021] Figure 9A and Figure 9B Various examples of guidewires for electrosurgical devices according to embodiments are depicted.

[0022] Figure 10 is a schematic diagram of a handheld electrosurgical system according to an embodiment.

[0023] Figure 11A An example guidewire having openings in the insulating coating of the guidewire is depicted in accordance with an embodiment.

[0024] Figure 11B An example guidewire having a helical cutout in the insulating coating of the guidewire is depicted in accordance with an embodiment.

[0025] Figure 12 is a flow chart depicting a method of using an electrosurgical system according to an embodiment.

[0026] Figure 13 is a flow chart depicting a method of varying the RF output delivered to a guidewire, according to an embodiment.

[0027] Figure 14 is a flow chart depicting a method of delivering RF output to a guidewire according to an embodiment.

[0028] Figures 15A-15B Depicted is an unintended lesion formed in a patient's heart by an electrosurgical device, according to an embodiment.

[0029] Figure 16 An electrosurgical device including a guidewire and a dilator according to an embodiment is schematically depicted.

[0030] Figure 17 An electrosurgical device including a guidewire and a dilator according to an embodiment is schematically depicted.

[0031] Figure 18 Depicts the guidewire as it is retracted within the dilator. Figure 16 and Figure 17 Current density and temperature around electrosurgical equipment.

[0032] Figure 19 Depicts the guidewire as it extends beyond the dilator and engages the septum Figure 16 and Figure 17 Current density and temperature around electrosurgical equipment.

[0033] Figure 20 Depicts the guidewire as it extends beyond the dilator and rests against the heart wall. Figure 16 and Figure 17 Current density and temperature around electrosurgical equipment.

[0034] Figure 21 Depicts the guidewire as it extends beyond the dilator and into the blood pool. Figure 16 and Figure 17 Current density and temperature around electrosurgical equipment.

[0035] Figure 22 yes Figure 16 and Figure 17 A graph of the temperature of an electrosurgical device over time when the device is located at the diaphragm.

[0036] Figures 23A-23CWhen the guidewire is at the septum and the insertion depth is 0.5 mm Figure 16 and Figure 17 A graph showing the terminal voltage, terminal current, and terminal impedance of an electrosurgical device.

[0037] Figure 24A and Figure 24B When the guidewire has been inserted through the septum and is against the heart wall (with myocardium) or deployed in the blood pool (without myocardium) with an insertion depth of 21.1 mm Figure 16 and Figure 17 Graph of the temperature of an electrosurgical device.

[0038] Figures 25A-25C When the guidewire has been inserted through the septum and is against the heart wall (with myocardium) or deployed in the blood pool (without myocardium) with an insertion depth of 21.1 mm Figure 16 and Figure 17 Graph of the terminal voltage of an electrosurgical device.

[0039] Figures 26A-26C When the guidewire has been inserted through the septum and is against the heart wall (with myocardium) or deployed in the blood pool (without myocardium) with an insertion depth of 21.1 mm Figure 16 and Figure 17 Graph of the terminal current of an electrosurgical device.

[0040] Figures 27A-27C When the guidewire has been inserted through the septum and is against the heart wall (with myocardium) or deployed in the blood pool (without myocardium) with an insertion depth of 21.1 mm Figure 16 and Figure 17 Graph of the terminal impedance of an electrosurgical device.

[0041] Figures 28A-28B is an example of a guidewire tip with an insulating collar according to an embodiment.

[0042] Figure 29 An electrosurgical device comprising a guidewire and a dilator according to an embodiment is schematically depicted, wherein the guidewire has an insulating collar.

[0043] Figures 30A-30C Depicted are the guidewire at the septum, heart wall, and blood pool. Figure 16 and Figure 29 Current density and temperature around electrosurgical equipment.

[0044] Figure 31A Depicted are examples of insulating collars over coil wires according to embodiments.

[0045] Figure 31B Depicted is an example of an insulating collar over a coil according to an embodiment.

[0046] Figure 32 Depicted are examples of insulating collars on guidewires according to embodiments.

[0047] Figure 33 Depicted are examples of insulating coils on a guidewire according to embodiments.

[0048] Figure 34 Depicted is an example of a guidewire tip with an insulating collar according to an embodiment.

[0049] Figure 35 is a schematic representation of achieving temperature control at the tip of an energy delivery device, according to an embodiment.

[0050] Figure 36 Depicted at the diaphragm Figure 16 and Figure 17 Current density around electrosurgical equipment.

[0051] Figure 37 Depicts the dilator retracted while the electrosurgical device is located at the heart wall and in the blood pool. Figure 16 and Figure 17 Current density around electrosurgical equipment.

[0052] Figures 38A-38B Is when the guidewire is deployed against the septum, has been inserted through the septum and is against the heart wall (with myocardium), or is deployed in the blood pool (without myocardium) Figure 16 and Figure 17 Graph of the current density around an electrosurgical device.

[0053] Figure 39 Depicts the dilator retracted while the electrosurgical device is located at the heart wall and in the blood pool. Figure 16 and Figure 29 Current density around electrosurgical equipment.

[0054] Figure 40 Depicted is an example of a guidewire tip with a marker band, according to an embodiment.

[0055] Figure 41 Depicts Figure 40 Cross-sectional view of the guidewire.

[0056] Figures 42A-42C A perspective view of a guidewire is depicted according to an embodiment. DETAILED DESCRIPTION

[0057] Various embodiments herein describe systems, devices, device components, and methods for puncturing and traversing tissue structures (e.g., including thin tissue structures such as the atrial septum). In particular, electrosurgical systems are configured to puncture and traverse thin tissue structures for biomedical applications. Aspects of these embodiments can provide safer, faster, or more convenient tissue puncture.

[0058] The example use of electrosurgical systems, components and devices as described herein is to facilitate transseptal puncture procedures (e.g., atrial crossing). Performing transseptal puncture (also referred to as atrial crossing) is a necessary procedure step for numerous cardiac interventional procedures, including cardiac ablation, left atrial appendage closure, and mitral valve transcatheter repair for the treatment of arrhythmias (such as atrial fibrillation and atrial flutter). These diseases and other diseases affect millions of people worldwide. For transcatheter treatment of the left side of the heart, a large-caliber sheath and device (e.g., approximately 8-12 French) can be delivered to the right atrium using a direct access from the large-diameter vena cava. After the catheter is delivered to the right side of the heart, a small puncture is performed on the atrial septum that separates the left and right sides of the heart to enter the left side of the heart. The atrial septum is composed of a thin fibrous structure called the fossa ovalis (FO).

[0059] The most common method for puncturing the septum is to insert a long guide catheter into the heart over a guidewire. The guide catheter is manipulated to position the distal tip in the FO. Once the FO is reached and confirmed by fluoroscopy or ultrasound imaging, the guidewire is removed and replaced with a long, rigid needle, called a transseptal needle. Because the transseptal needle is rigid, it may require manual shaping outside the body to bring it to the desired position on the FO. With the transseptal needle, mechanical force is applied and the sharp distal end of the needle punctures the FO. Once the puncture is complete, the transseptal needle is removed, the guidewire is reinserted, and its distal tip is advanced into the left atrium. With the guidewire in place, the physician can deliver a variety of therapeutic devices to the left atrium based on their preference and the treatment to be performed.

[0060] However, mechanical systems that rely on rigid needles have certain disadvantages and may not always effectively pierce the septum. Furthermore, such systems require additional components (e.g., a rigid needle) to facilitate piercing and traversing the septum. In contrast, the electrosurgical systems described herein can effectively pierce and traverse the septum to facilitate the delivery of other therapeutic devices.

[0061] The electrosurgical systems, components and devices described herein have several advantages. By combining the guidance and puncture functions into one tool or device, at least one device exchange can be eliminated. Each device exchange (i.e., removing one device from the patient's body and replacing it with another) is associated with an increased risk of adverse events (such as air embolism leading to stroke, accidental puncture of a blood vessel, or increased procedure time due to device displacement). Because the distal end of the novel electrosurgical guidewire is flexible (e.g., flexible enough to follow the shape of a sheath and / or dilator), it can be used in conjunction with a steerable guide catheter or sheath without the need to remove the device from the body for manual shaping. The ability of the flexible distal tip to be steered and manipulated by the sheath facilitates accurate positioning on the FO and optimal traversal position for various patient anatomical structures.

[0062] Some electrosurgical systems use an electrosurgical guidewire that is inserted into an expander and connected to an electrosurgical generator via a spring clip. When a button or foot switch on the generator is pressed, the generator can apply RF energy to the distal end of the electrosurgical guidewire. The electrosurgical system described herein improves on such electrosurgical systems in several ways. First, the electrosurgical system described herein includes an interface for coupling an energy delivery element to the generator, in which the energy delivery element can slide relative to a fixed electrode within the interface, thereby allowing the energy delivery element to be easily advanced or retracted. In some embodiments, the interface can be coupled to the back of the energy delivery element so that the energy delivery element can be easily guided. Second, the energy delivery elements (such as guidewires) used in the systems described herein can be manufactured using batch processes for coating and electroplating, which facilitates the manufacture of lower-cost devices. Third, the systems described herein can include a button or other actuation mechanism physically close to the sheath, thereby enabling a single user to control the timing of electrosurgical energy delivery and the position of the guidewire from one location. Moreover, the actuation mechanism can be located on a single device as an electrosurgical energy connector or interface (instead of being located on a generator control panel or foot switch coupled to the generator) so that a single cable can be used to provide the necessary electrical connections for the generator. Fourth, the energy delivery element (such as a guide wire) used in the system described herein can have a coiled design with a large surface area and, when plated with an efficient thermal conductor (such as gold), can have improved heat transfer, which reduces the operating temperature of the electrosurgical tip during treatment. This can reduce the risk of burns or thrombosis due to excessive temperatures. Fifth, the guide wire used in the system described herein can have an insulating collar that allows the tip of the guide wire to guide RF energy during treatment. Sixth, because the electrical connection between the generator and the electrosurgical device allows the doctor to easily slide or move the guide wire without generating additional interference, the doctor can rely on tactile feedback (e.g., due to the behavior of the guide wire tip) to assess when the guide wire is in contact with the tissue surface.

[0063] The following sections provide further details of the electrosurgical systems, devices, and methods described herein.

[0064] Electrosurgical systems and equipment

[0065] Figure 1 is a schematic diagram of an electrosurgical system 100 according to an embodiment. The electrosurgical system 100 includes a generator 110, an electrosurgical device or assembly 120, and a return electrode 130.

[0066] The generator 110 can be configured to generate energy, such as, for example, radio frequency (RF) energy. The generator 110 can include a memory 112, a processor 114, an energy source 116, and an input / output device 118. In some embodiments, the generator 110 can be coupled to an external power source 102, such as, for example, a direct current (DC) power supply. The generator 110 can include a plug or adapter that can be used to plug into an outlet. Alternatively, or in addition, the generator 110 can include a built-in power source, such as, for example, a battery.

[0067] The memory 112 may include a database (not shown) and may be, for example, a random access memory (RAM), a memory buffer, a hard drive, an erasable programmable read-only memory (EPROM), an electrically erasable read-only memory (EEPROM), a read-only memory (ROM), flash memory, etc. The memory 112 may store instructions to cause the processor 114 to execute modules, processes, and / or functions associated with the system 100, such as voltage waveform generation and / or impedance monitoring, as further described below.

[0068] The processor 114 can be any suitable processing device configured to run and / or execute a collection of instructions or codes. The processor can be, for example, a general-purpose processor, a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), a digital signal processor (DSP), etc. The processor can be configured to run and / or execute application processing and / or other modules, processes, and / or functions associated with the system and / or a network associated therewith (not shown). The underlying device technology can be provided in a variety of component types, for example, metal oxide semiconductor field effect transistor (MOSFET) technology (such as complementary metal oxide semiconductor (CMOS)), bipolar technology (such as emitter coupled logic (ECL)), polymer technology (such as silicon-conjugated polymer and metal-conjugated polymer-metal structures), mixed analog and digital, etc.

[0069] The energy source 116 can be configured to convert, store, and / or supply energy, for example, in the form of a voltage waveform. In some embodiments, the energy source 116 can include an alternating current (AC) / DC switch. In some embodiments, the energy source 116 can include one or more capacitors to store energy from the power supply. In some embodiments, the energy source 116 can be configured to generate and deliver a voltage waveform, for example, to the electrosurgical device 120. In some embodiments, the voltage waveform can be an oscillating sinusoidal RF waveform. The voltage waveform can have a frequency between approximately 200 kHz and approximately 1 MHz, including all subranges and values ​​therebetween. For example, in some applications, the voltage waveform can have a frequency between approximately 350 kHz and approximately 500 kHz, or a frequency of approximately 450 kHz. The voltage waveform can have a peak voltage between approximately 100 V and approximately 400 V, including all subranges and values ​​therebetween. For example, in some applications, the voltage waveform can have a peak voltage between approximately 150 V and approximately 250 V, or a peak voltage of approximately 200 V.

[0070] The input / output device 118 can be configured to provide a communication interface between the operator and the system 100. The input / output device 118 can include one or more input devices and output devices. In some embodiments, the input device of the input / output device 118 can include a touch screen or other touch-sensitive device, a stepping switch, a foot pedal, a keypad, a keyboard, buttons, a joystick, etc. In some embodiments, the output device of the input / output device 118 can include one or more of a display device and an audio device. The display device can include at least one of a light emitting diode (LED), a liquid crystal display (LCD), an electroluminescent display (ELD), a plasma display panel (PDP), a thin film transistor (TFT), and an organic light emitting diode (OLED). The audio device can output patient data, sensor data, system data, other data, alarms, warnings, etc. in an audible manner. The audio device can include at least one of a speaker, a piezoelectric audio device, a magnetostrictive speaker, and / or a digital speaker.

[0071] The generator 110 can be coupled to the electrosurgical device 120 and the return electrode 130. In use, the signal generator 110 is configured to generate a voltage waveform for piercing tissue (such as, for example, the atrial septum). For example, the generator 110 can be configured to generate and deliver a voltage waveform to the electrosurgical device 120. The return electrode 130 can be coupled to the patient (e.g., deployed on the patient's back, torso, or limbs (such as legs)) to allow current to flow from the electrosurgical device 120 through the patient and then to the return electrode 130 to provide a safe current return path from the patient.

[0072] In some embodiments, the generator 110 can be operated in a constant power mode, typically set at about 5 to about 25 W. In some embodiments, the generator 110 can implement feedback loop control, for example, via a controller of the generator or a controller operatively coupled to the generator. For example, the generator 110 (or the controller) can include circuitry configured to determine the impedance of the circuit from the generator 110 to the electrosurgical device 120, to the return electrode 130, and back to the generator 110. The processor 114 or other processing circuitry within the generator 110 can be configured to monitor the impedance of the circuit and modulate the voltage output so that it does not exceed a preset or predetermined electrical power (P max ). In some embodiments, P max can be between about 5W and about 100W, including all subranges and values ​​therebetween. For example, P max It can be between about 45W and about 55W, or about 50W. During electrosurgery, the impedance of the circuit can start at about 1500 ohms, but rise to 2000 ohms as the biophysical characteristics of the tissue target change. For example, as the energy delivery device or guidewire contacts tissue, cuts tissue, and reaches a blood pool, the impedance can change. Therefore, the generator 110 can be configured to monitor such changes in impedance and adjust the parameters of the voltage waveform. In some embodiments, the generator 110 can be configured to modify the RF output based on the characteristics of the energy delivery element 124 (e.g., output current, current density, temperature, etc.). Some electrosurgical waveform generators can operate in a constant power control mode, for example, in which the impedance of the circuit is continuously measured and the voltage of the RF waveform is adjusted to produce a fixed electrical power. For example, in an application involving a generator set to produce a constant power of 50W, as the tissue impedance increases, the voltage of the voltage waveform can rise sharply to a maximum voltage V of 3000V (peak-to-peak) or more. max , to produce a constant power of 50W. This presents complications because any connected electrosurgical device must have adequate electrical insulation to prevent dielectric breakdown or current leakage, which can be dangerous to the patient or operator at high voltages. The high voltages associated with these power-controlled electrosurgical generators can produce sparks and electrocautery at the tip of the guidewire, which can produce significant bubbles, clots, and char formation. For intravascular devices within the left atrium of the heart, these can lead to ischemic stroke or other complications. In some embodiments, the generator is configured to vary the RF output over time. For example, the generator can provide a first output for a first time period, a second output for a second time period, a third output for a third time period, and so on.

[0073] Given the lower operating voltage of the generator 110 and the use of a feedback control scheme that maintains power below a predetermined peak power, the systems and devices described herein can be used with electrosurgical devices having a smaller cross-section. For example, by operating at a lower voltage (e.g., a voltage between about 150V and about 250V), the generator 110 can allow the use of electrosurgical devices with smaller insulators or less insulating material. In particular, the ability of an insulated wire to resist dielectric breakdown is directly related to the thickness of the insulator. Therefore, with a lower voltage, an electrosurgical wire with a thinner insulating coating can be used. In some embodiments, the coating thickness of the guide wire is negligible compared to the diameter of the core of the guide wire, which can result in improved mechanical properties of the energy delivery element 122. In addition, because the insulator is thin, it can be applied to the guide wire core via low-cost manufacturing techniques (such as dip coating or spray coating).

[0074] In some embodiments, the generator 110 can be configured to modulate the voltage output based on the temperature of the distal tip of the energy delivery element 124. As described above, using an RF-powered guidewire or needle to create an atrial-septal defect (e.g., for transseptal access) can pose a thromboembolic risk due to the unintended generation of chars and / or clots. When the tissue reaches a temperature above a threshold, chars and clots are generated, which cause a cascade of protein denaturation, dehydration, and thrombosis. Maintaining the tip temperature below the threshold will prevent the formation of chars and clots, thereby avoiding thromboembolic risks for the patient. Therefore, in some embodiments, the generator 110 can be configured to deliver a voltage output to the energy delivery element 124 until a target set point temperature or range is reached. In some embodiments, the target set point temperature or range can be between approximately 55 and approximately 80 degrees Celsius. In operation, when the guidewire is located at the desired area of ​​tissue contact, the user can initiate RF output from the generator, for example, by actuating an actuator (e.g., a button or slider that can be located on the electrosurgical interface 122 described below). The generator 110 can then deliver current to achieve the target set point temperature. By avoiding temperatures above approximately 80 degrees Celsius, the occurrence of scorching and clot formation can be reduced or avoided. Figure 36 Further details of achieving temperature control are described.In an embodiment, an electrosurgical system includes both a power limited generator and a low voltage tip.

[0075] The electrosurgical device or assembly 120 may include an electrosurgical interface 122, an energy delivery element 124, and a sheath 126. Although the electrosurgical device 120 is described as a single device, it will be appreciated that each of the electrosurgical interface 122, the energy delivery element 124, and the sheath 126 may be implemented as separate devices and / or as components of two or more devices.

[0076] The electrosurgical interface 122 establishes an electrical connection between the generator 110 and the energy delivery element 124 while allowing sliding translation of the energy delivery element 124 therein. The electrosurgical interface 122 may be coupled to, couplable with, or include a cable connected to the generator 110 and an interface for receiving the energy delivery element 124. Figures 3A-3C As described in more detail in , the interface 122 may include an electrical coupling element electrically connected to the generator 110 (e.g., via a cable). In embodiments, the electrical coupling element is an electrode, and the electrosurgical interface 122 includes a conductive fluid layer in electrical contact with the electrode. The energy delivery element 124 can then be received in the conductive fluid and electrically coupled to the electrode via the conductive fluid. The energy delivery element 124 can slide within the conductive fluid without losing electrical coupling to the electrode. In some embodiments, the electrical coupling between the energy delivery element 124 and the electrosurgical interface 122 can include direct coupling, fluid coupling, inductive coupling, etc. In some embodiments, the interface 122 can be electrically coupled to the end of the energy delivery element 124. Figures 3A-3C Further details of the electrosurgical interface 122 are provided.

[0077] In some embodiments, the electrosurgical device 120 may include a button, slider, or other actuation device for establishing an electrical connection between the generator 110 and the electrosurgical interface 122. For example, a button or slider may be provided on the electrosurgical device 120, e.g., near where a user may manipulate the energy delivery element 124 and / or other components of the electrosurgical device 120, and the button may be pressed or the slider may be slid to establish an electrical connection between the generator 110 and the electrodes of the electrosurgical interface 122. Alternatively, or in addition, the button, slider, or other actuation device may be actuated to send a signal to the generator 110, e.g., via a wired or wireless connection to the generator 110. In some embodiments, the signal may be an activation (on or off) signal. In some embodiments, the signal may trigger the generator 110 to send RF energy (e.g., a pulse waveform) to the electrosurgical device 120. In some embodiments, the signal may be a voltage signal, a current signal, or an impedance signal, which may be transmitted to the generator 110, and the generator 110 may deliver an RF waveform to the electrosurgical device 120 in response to receiving the signal. In some embodiments, the electrosurgical interface 122 and the generator 110 are configured to communicate to identify the type of and / or information about the electrosurgical interface 122, the generator 110, and / or the energy delivery element 124. For example, the generator 110 can determine whether the energy delivery element 124 has been previously used for a procedure. In some embodiments, the generator 110 can be configured to prevent reuse of the energy delivery element 124 to reduce the chance of contamination.

[0078] In some embodiments, the electrosurgical interface 122 may include a cutting feature to remove portions of the insulating sleeve of the energy delivery element 124 to electrically couple to the energy delivery element 124. In some embodiments, the electrosurgical interface 122 may include a button that, when activated, operates a cutting blade to expose the conductive portion of the energy delivery element 124.

[0079] The energy delivery element 124 may include an electrode or other conductive element for applying energy to a tissue structure. In embodiments, the energy delivery element 124 is a wire (e.g., a guidewire) including a distal conductive tip that is used to apply energy to and thereby penetrate the tissue structure. In some embodiments, the energy delivery element 124 includes a distal tip that can transition between different configurations or shapes, e.g., a curved configuration and a straight configuration. In some embodiments, the energy delivery element 124 may have a shape memory tip that automatically assumes a preset shape or configuration when it is withdrawn from the sheath beyond a certain amount (e.g., withdrawn from the sheath 126, as described below). For example, the energy delivery element 124 may have a shape memory tip that automatically bends or assumes a curved shape or atraumatic configuration (e.g., when bent, the curved portion becomes the distal-most portion of the energy delivery element 124, making it less sharp and less likely to damage non-target tissue). Alternatively or additionally, the guidewire can include a spring tempered stainless steel portion that can return to a predetermined shape when released from a restraining sheath (such as an expander discussed below). In some embodiments, the energy delivery element 124 can include a coil structure that is at least partially coated (e.g., with an insulating layer). In some embodiments, the energy delivery element 124 can be formed from a metal and a polymer material. In some embodiments, the energy delivery element 124 can include more than one coil structure. For example, a coated coil structure and an uncoated coil structure. In some embodiments, the energy delivery element 124 can include an insulating coating near the tip. In some embodiments, the energy delivery element 124 can include a material (e.g., tantalum, tungsten, etc.) that provides radiopacity, echogenicity, and / or insulation near the distal tip.

[0080] In some embodiments, the energy delivery element 124 can have a large active electrode area, e.g., greater than about 1 cm, greater than 2 cm, greater than 3 cm, greater than 4 cm, greater than 5 cm, greater than 10 cm, or between about 1 cm and about 20 cm (including all values ​​and subranges therebetween). The active electrode area can include the distal conductive tip of the energy delivery element 124 and the conductive outer portion of the energy delivery element 124, e.g., the conductive outer coil, the plating, etc. The larger active electrode area can provide cooling for the tip because the conductive / non-insulated area of ​​the guidewire can wick or conduct away heat. The larger active electrode area can also reduce the current density at the distal tip of the energy delivery device 124, thereby reducing the risk of lesion formation.

[0081] In some embodiments, the energy delivery element 124 may include at least one sensor. The at least one sensor may be located at the tip of the guidewire, near the tip of the guidewire, in the distal portion, in the proximal portion, etc. As used herein, proximal refers to the portion of the device or component closest to the surgeon, while distal refers to the portion closer to the patient's anatomy. The sensor may be configured to measure properties of the guidewire. For example, the sensor may be configured to measure temperature, current density, pressure, etc. In some embodiments, the sensor may be used to locate the tip in an electroanatomical mapping system, thereby allowing the guidewire to be positioned in the cardiac space. In some embodiments, the sensor may be a temperature sensor, such as a thermistor or thermocouple. In some embodiments, the sensor may be a bimetallic thermocouple, for example, with a weld between the outer coil wire and one or more core wires. The proximal joint of the coil and the core wire(s) may be used as a bimetallic thermocouple. In some embodiments, the sensor may be a thermistor integrated into the coil of the guidewire. The sensor may be used to provide feedback in response to an out-of-range reading to reduce power or shut down the power supply, thereby improving the safety of the procedure.

[0082] In some embodiments, the energy delivery element 124 may have a proximal length or portion coated with an insulator and a distal length or portion not coated with an insulator. The coated portion can be grasped or manipulated by an operator (e.g., a surgeon) during an electrosurgical procedure. In some embodiments, the energy delivery element 124 may be formed of a material that allows the surgeon to quickly identify or recognize the energy delivery element 124. For example, the energy delivery element 124 may have a two-tone design comprising a metallic distal colored portion and a non-conductive proximal colored portion. The metallic portion may extend along the energy delivery element 124 toward a set point (e.g., a midpoint) and act as a continuous conductor from the set point to the distal end of the guidewire. The metallic portion may include a metallic coating or other conductive material that covers manufacturing traces resulting from welding, heat setting, or shaping, thereby producing a consistent, smooth surface finish. In some embodiments, the metallic portion may include gold plating on stainless steel or another base material (e.g., tungsten). The proximal portion may have a polymer coating or other insulating material that insulates the energy delivery element 124. The polymer may be extruded, reflowed, or applied by coating. Suitable examples of such insulating materials include polytetrafluoroethylene (PTFE), polyimide and nylon. The metal portion and the proximal non-conductive portion may have the same or different lengths. Figures 8A-9B 、 Figure 16 、 Figure 17 、 Figures 28A-29 、 Figures 31A-34 and Figure 40-42C Further details of exemplary electrosurgical guidewires are described.

[0083] When used with the electrosurgical interface 122, the conductive portion of the energy delivery element 124 can be coupled to the electrosurgical interface 122, allowing energy to be transferred to the distal tip of the energy delivery element 124 via the conductive core of the energy delivery element 124. In some embodiments, the energy delivery element 124 can comprise stainless steel to conduct energy (e.g., a stainless steel core, a stainless steel outer coil, etc.). In some embodiments, portions of the energy delivery element 124 can be formed and / or coated with materials such as gold, platinum, and / or other highly conductive materials to improve heat transfer and reduce the operating temperature of the tip of the energy delivery element 124 during surgical procedures. For example, the energy delivery element 124 can be formed from such materials and / or coated or plated with such materials. Alternatively, materials such as tungsten or tantalum can be incorporated into the energy delivery element 124 for their radiopacity. In one embodiment, the energy delivery element 124 is a conductive metal wire that can have a coiled design with a large surface area and be plated with a good thermal conductor (such as gold) to improve heat transfer and reduce the operating temperature of the tip. This can, in turn, reduce the risk of scorching or thrombosis due to excessive temperatures.

[0084] A sheath 126 (e.g., an insulating shaft) can be used with a guidewire or other energy delivery element 124. The sheath 126 comprises a cannula having a lumen whose inner diameter is sized to receive the energy delivery element 124 and allow the energy delivery element 124 to slide along the axis of the sheath. The sheath 126 can provide support for the guidewire as it passes through the patient's anatomical structure. In some embodiments, the sheath 126 can be configured to limit or shape the energy delivery element 124. For example, as described above, in some embodiments, the energy delivery element 124 can have a distal tip that is configured to transition between a curved configuration and an extended or straight configuration. The energy delivery element 124 tip can be formed of a shape memory material or a spring biased material and be straight when constrained by an outer sheath (e.g., sheath 126) and curved when not constrained by the outer sheath. This can be desirable because the guidewire has an anti-traumatic shape that can avoid accidental damage to nearby patient anatomical structures. The sheath 126 can then be used to constrain the energy delivery element 124 into a straight configuration such that the tip of the energy delivery element 124 can contact and perforate through tissue structures when advanced distally a first distance along the length of the sheath, but bends when advanced to a greater distance where it is more likely to encounter non-target anatomical structures. For further details on this, see Figures 8A-8C and Figures 42A-42C 1. In some embodiments, the sheath 126 may include or be used with a dilator. After the energy delivery element 124 forms a perforation or opening in a tissue structure, the dilator may be advanced to dilate the opening, for example, to facilitate delivery of an auxiliary treatment device, such as an ablation catheter, sheath, or other medical device. In some embodiments, the electrosurgical system 100 includes a dilator without a sheath.

[0085] The energy delivery element 124 can be designed to be universally compatible with a variety of sheaths, dilators, and / or other devices. In some embodiments, the energy delivery element 124 can be used with a variety of sheath types 126. Thus, a surgeon or practitioner can select the appropriate sheath during a particular procedure without having to make any special adaptations to the system for use with the selected sheath.

[0086] In some embodiments, the guidewire or other energy delivery element 124 may include an insulating collar disposed near the distal end of the energy delivery element 124. The insulating collar may have a length between about 2 mm and about 10 mm, including all subranges and values ​​therebetween. The insulating collar surrounds the conductive portion near the distal end of the energy delivery element 124. In some embodiments, the insulating collar may be disposed between about 0.5 mm and about 3 mm from the distal end of the energy delivery element 124, including all subranges and values ​​therebetween. In operation, when the energy delivery element 124 is extended distally out of the sheath, the conductive tip of the guidewire is exposed. Further extension of the energy delivery element 124 out of the sheath exposes the insulating collar of the energy delivery element 124. The insulating collar may act as an extension of the insulating sheath, keeping the total surface area of ​​the exposed conductive portion of the energy delivery element 124 small, thereby maintaining a higher current density near the distal tip of the energy delivery element 124. This ensures that when the energy delivery element 124 is extended a short distance out of the sheath, the distal tip of the energy delivery element 124 has sufficient energy to penetrate the septum. As the guidewire is further extended out of the sheath and inserted into the blood pool outside the septum (e.g., the left atrium), additional conductive portions of the energy delivery element 124 become exposed, thereby reducing the current density at the distal tip of the energy delivery element 124. This reduces the risk that the energy delivery element 124 may contact and inadvertently damage the heart wall (e.g., the myocardium) after being removed from the septum. Figures 28A-42C Further details of the characteristics and operation of a guidewire with an insulating collar are described.

[0087] Figure 2 is a schematic diagram of an electrosurgical system 200 according to an embodiment. The structure and / or function of the electrosurgical system 200 can be similar to other electrosurgical systems described herein, such as, for example, the electrosurgical system 100. For example, the electrosurgical system 200 can include an electrosurgical device 220 (e.g., similar in structure and / or function to the electrosurgical device 120), an electrosurgical generator 210 (e.g., similar in structure and / or function to the generator 110), and a return electrode 230 (e.g., similar in structure and / or function to the return electrode 130).

[0088] Similar to electrosurgical system 100, electrosurgical system 200 can be configured to penetrate and traverse thin tissue structures for biomedical applications. System 200 includes a generator 210, an interface 222 with electrical contacts secured to a fluid lumen of an intravascular sheath or dilator, a removable guidewire 224 (e.g., an example of energy delivery element 124) that delivers electrosurgical energy to a treatment target (e.g., a tissue structure within a patient's body), and a return electrode 230 that is attached to the patient's body.

[0089] In use, electrosurgical energy flows from the generator 210 into the patient's body and to the exposed tip of the guidewire 224, which contacts the target tissue. The circuit is completed by a return electrode 230 attached to the patient's body, which can be located on the torso or an extremity, such as the patient's leg. In some embodiments, the electrosurgical generator 210 connected to the electrosurgical device 220 can generate an oscillating sinusoidal RF waveform having a frequency of approximately 450 kHz and a peak voltage of approximately 200 V. In some embodiments, the generator 210 can operate in a constant power mode, with a setting between approximately 5 W and approximately 25 W.

[0090] In some embodiments, similar to the generator 110, the generator 210 can implement a feedback loop control scheme whereby the generator 210 adjusts one or more parameters of the RF waveform based on measured impedance or other characteristics of the circuit. The generator 210 may include circuitry for monitoring the electrical impedance of the circuit from the generator 210 to the electrosurgical device 220, to the return electrode 230, and back to the generator 210. The generator 210 (e.g., via an onboard processor or circuitry) can calculate the instantaneous power, as provided by the formula P=I*V, where P is power, I is current, and V is voltage. The generator 210 can be programmed to have a predetermined peak voltage (V peak ) and peak power (P peak ), and during electrosurgery, the peak voltage of the voltage waveform can be set to V peak , unless the calculated instantaneous impedance value is exceeded, in which case V is reduced to keep the power below or equal to P max .

[0091] Electrosurgical interface

[0092] In some embodiments, the electrosurgical interface as described herein may include a sliding contact design. More specifically, the electrosurgical interface may establish an electrical coupling between the generator and the guidewire while allowing the guidewire to slide or move within the interface. In existing sliding contact interfaces, electrical coupling may be established via a physical contact conductor engaged with a second contact member (such as a metal wire or metal plate). If the two move relative to each other, this may result in resistance and potential wear of the second contact member. For electrosurgical guidewires, the contact or interacting portion may include a thin coating that is susceptible to wear and ultimately produces particles. For intravascular applications, this particle generation may result in patient injury and other complications. For electrosurgical guidewires, the friction between the contact portion and the second contact member may also result in a weakened tactile response or feel of the catheter, resulting in an inability to engage a therapeutic target located distal to the contact portion of the guidewire. To address these shortcomings, a spring-loaded electrical contact (e.g., an electrosurgical interface) may be used that is clamped to the proximal end of the electrosurgical guidewire. However, this requires a physical clamp or fixture to transmit the electrosurgical energy from the generator, which limits the extent of movement of the electrosurgical guidewire.

[0093] The electrosurgical devices described herein provide electrical coupling without the need for direct or physical contact and / or clamps or springs, which are associated with the aforementioned disadvantages. Figure 4-5C An electrosurgical device 420 is depicted in accordance with an embodiment. Figure 4 A perspective view of an electrosurgical device 420 is provided. Figure 5A and Figure 5B A detailed view of an electrosurgical interface 422 of an electrosurgical device 420 is depicted. Figure 5C A side view of an electrosurgical device 420 is depicted with breaks to better illustrate the details of the various components of the electrosurgical device 420. The electrosurgical device 420 may be functionally and / or structurally similar to Figure 1 Similar to the electrosurgical device 120.

[0094] like Figure 4 As depicted in FIG, the electrosurgical device 420 includes an electrosurgical interface 422 (e.g., a device that is functionally and / or structurally similar to Figure 1 ), a cable 442, a guidewire 424 (e.g., functionally and / or structurally similar to the electrosurgical interface 122 of Figure 1 124) and an expander 426 (e.g., similar in function and / or structure to the sheaths and other expanders described herein).

[0095] The electrosurgical interface 422 is electrically coupled to a cable 442, which may be electrically coupled to a generator, such as Figure 1 The generator 110. The electrosurgical interface 422 establishes an electrical connection between the generator and the conductive portion of the guide wire 424. Figure 1As depicted, the electrosurgical interface 422 can include a button or actuator for switchably or selectively establishing an electrical connection between the generator and the guidewire 424. The electrosurgical interface includes a housing that is electrically insulated from the current-carrying components of the electrosurgical interface 422, thereby allowing for safe and comfortable handling of the electrosurgical interface 422. In some embodiments, the housing is made of plastic. In some embodiments, the housing is approximately 1-2 inches long, including all values ​​and subranges therebetween.

[0096] The electrosurgical interface 422 is configured to establish and maintain an electrical connection with the guidewire 424 even if the guidewire 424 moves or translates within the electrosurgical interface 422. The electrosurgical interface 422 includes a fixed electrode that is connected to the output of the generator via a cable 442. When the guidewire 424 is inserted into the lumen of the electrosurgical interface 422, the fixed electrode contacts the conductive portion of the guidewire 424 and can provide an electrical connection to the generator via the cable 442. Figures 3A-3B The structure of electrosurgical interface 422 is described in further detail.

[0097] The guidewire 424 includes a tip 424a at the distal end of the guidewire 424. The tip 424a of the guidewire 424a is configured to apply energy to the tissue structure. The guidewire 424 can extend through the electrosurgical interface 422, wherein electrodes or other conductive elements of the electrosurgical interface 422 are electrically coupled to the conductive portion of the guidewire 424 to provide power from the generator to the guidewire 424. The portion of the guidewire 424 that can contact the electrosurgical interface 422 can be conductive, while the portion of the guidewire 424 that is not in contact with the electrosurgical interface 422 can be insulated or non-conductive. Figures 8A-9B Guidewire 424 is further described.

[0098] After being so deployed, guide wire 424 comprises the part extending through electrosurgical interface 422 and the part being arranged in the lumen of dilator 426. Optionally, the tip 424a of guide wire 424 can be configured to have bending or J-shape when being unconstrained, for example, being deployed outside dilator 426, dilator 426 can have enough rigidity to constrain the tip 424a of bending. In use, guide wire 424 can be navigated through patient vascular system under its unconstrained structure, for example. Electrosurgical interface 422 and dilator 426 can be loaded onto guide wire 424 and dilator 426 can be advanced (for example, vascular system and enter heart) by patient anatomical structure. Dilator 426 can be insulated any conductive part being deployed in dilator 426 in guide wire 424 to protect patient from the influence of undesirable energy delivery. The tip 424a of guide wire 424 advances, until it is positioned at the far side of the far end of dilator 426. The expander 426 is configured to constrain the guidewire 424 to a straightened configuration when the tip 424a of the guidewire 424 is substantially disposed within the expander 426. Figure 4Thus, the expander 426 can have sufficient rigidity to keep the tip 424a of the guidewire 424 straight when positioned within the expander 426. In use, the tip 424a can remain relatively straight when advanced to a first distance outside the sheath and bend when advanced to a greater distance. The straightened configuration of the guidewire 424 can correspond to the location of energy delivery via the tip 424a of the guidewire 424, as described below with reference to Figure 8B Further described.

[0099] In an embodiment, the expander 426 is coupled to the electrosurgical interface 422 so that the expander 426 moves in conjunction with the electrosurgical interface 422. For example, the expander 426 can be coupled to the electrosurgical interface 422 via a Luer connection or a similar partial-turn connector, but other types of connectors are known in the art. Because the expander 426 is coupled to the electrosurgical interface 422, the user can advance the expander 426 and set its position by pushing or moving the electrosurgical interface 422. In some embodiments, more refined movement and / or control of the expander 426 may also be possible, for example, by manipulating an actuator (e.g., a knob, a slider, etc.) that can extend or retract the expander 426 relative to the electrosurgical interface 422. In some embodiments, the expander 426 can be used to expand the opening created by the guide wire 424, thereby delivering energy to the target location.

[0100] exist Figure 5AIn the embodiment depicted in , the electrosurgical interface 422 includes a housing 422a, a button 422b, an expander interface 422c (e.g., a coupler), and a cable portion 442a that terminates in a cable plug 442b. The housing 422a houses the internal components of the electrosurgical interface 422 and insulates and protects the operator and patient from the electrical components of the electrosurgical interface 422a. In some embodiments, the housing 422a is made of an insulating material, such as plastic, rubber, etc. The housing 422a can have an ergonomic shape for easy handling; for example, its central portion is narrow to make it easy to hold firmly. The button 422b is disposed on the housing 422a. When actuated, the button 422b allows the guidewire 424 to receive energy, for example, from the generator 110 coupled to the electrosurgical interface 422. In some embodiments, the button 422b can be coupled to a processor or other device configured to control the delivery of energy to the guidewire 424. In some embodiments, the processor 422b is actuated to provide energy to the guide wire 424. For example, when button 422b is actuated, a signal can be sent to the processor, and the processor can control the electrosurgical interface 422 to provide energy to the guide wire 424 for a predetermined time. In some embodiments, when button 422b is pressed, energy is provided to the guide wire 424. Alternatively, when the button is released (for example, such as using a spring button or a slider), the circuit is disconnected. In such embodiments, pressing button 422b can establish electrical connection between electrosurgical interface 422 and guide wire 424 and / or the generator, so that a closed circuit can be formed between these various electrical components with return electrode 130. In some embodiments, button 422b is a toggle switch, for example, for opening and closing the delivery of energy to the guide wire 424. In such embodiments, the processor can be configured to control switching, and / or pressing a button can mechanically close the switch, and then the switch is connected to the generator power supply to the guide wire 424.

[0101] The expander interface 422c allows the expander 426 to be selectively coupled to the electrosurgical interface 422. In some embodiments, the expander interface 422c includes a locking mechanism to prevent the expander 426 from being decoupled from the electrosurgical interface 422. The expander interface 422c also allows for the establishment of a continuous lumen to receive the guidewire 424 so that the expander 426 can be advanced along the guidewire through the electrosurgical interface 422 during a surgical procedure. The electrosurgical interface 422 receives energy via a cable 442, which includes a cable portion 442a and a cable plug 442b. The cable portion 442a directs energy into the electrosurgical interface 422, while the cable plug 442b interfaces with the generator.

[0102] like Figure 5B448. In some embodiments, the cable portion 442a is electrically coupled to the conductive path 444. The conductive path 444 carries energy from the cable 442 to the electrode 448. In some embodiments, the hourglass structure can be deployed near the electrode 448 and defines at least a portion of the lumen for receiving the guide wire 424. The electrode 448 allows the guide wire 424 to slide in the guide wire lumen while maintaining the constant electrical coupling between the electrode interface 422 and the guide wire 424. In some embodiments, the electrical coupling between the electrode interface 422 and the guide wire is established via a conductive fluid, similar to that described above with reference to FIG3. For example, a conductive fluid can fill the space (e.g., chamber) around the guide wire 424 and the electrode 448 to provide lubrication / reduce friction and establish conductivity. In some embodiments, the electrode is electrically coupled to the guide wire via a spring. The spring can apply pressure to the electrode, thereby maintaining constant electrical coupling while allowing the guide wire to translate relative to the spring.

[0103] In some embodiments, the electrosurgical interface 422 may include an additional port 422d. The port 422d may be configured to couple to one or more other devices, such as for flushing a lumen or guidewire lumen with a fluid, etc. In some embodiments, the port 422d may also be configured to receive a guidewire 424.

[0104] Figure 5C A guidewire 424 is depicted extending through the electrosurgical interface 422 and the dilator 426. The guidewire 424 extends through the interface 422d, contacts the electrode 448, and extends through the dilator interface 422c and the dilator 426. Figure 5C 4, the guidewire 424 is shown retracted within the dilator 426. As discussed above, in operation, the tip 424a of the guidewire 424 can be extended and deployed distally of the distal end of the dilator 426 so that the guidewire 424 can optionally form a J-shape (or other atraumatic shape).

[0105] Figures 6A-6C An electrosurgical interface 522 (e.g., having functionality and / or structure similar to that of Figure 1 The electrosurgical interface 122 and / or Figure 4-5C similar to the electrosurgical interface 422 in FIG. Figure 6A A top view of electrosurgical interface 522 is depicted. Figure 6B A side view of electrosurgical interface 522 is depicted. Figure 6C A top view of electrosurgical interface 522 is depicted, showing the internal components of the electrosurgical interface.

[0106] Similar to electrosurgical interface 422, electrosurgical interface 522 is configured to establish an electrical connection with a guidewire (eg, its function and / or structure is similar to that of Figure 1The guidewire is connected to the electrosurgical interface 522 and maintains the connection as the guidewire moves or translates within the electrosurgical interface 522. The electrosurgical interface 522 includes a housing 522a (e.g., having a function and / or structure similar to that of the electrosurgical interface 522). Figures 5A-5C similar to the housing 422a), actuator 522b (e.g., having a function and / or structure similar to Figures 5A-5C 422b), expander interface or coupler 522c (e.g., having the same function and / or structure as Figures 5A-5C similar to coupler 422c), cable portion 542a (e.g., having the same function and / or structure as Figures 5A-5C 442a), a cable plug 542b (e.g., having a function and / or structure similar to that of Figures 5A-5C 442b) and an additional port 522d (e.g., similar in function and / or structure to the cable plug 442b). Figures 5B-5C similar to the additional port 522d).

[0107] The actuator 522b of the electrosurgical interface 522 is a sliding actuator that, in operation, translates from a first position (e.g., an inactive position) to a second position (e.g., an active position). In some embodiments, the first position may be a more proximal position, and the second position may be a more distal position. Although the actuator 522b is a sliding actuator, the actuator 522b may be similar to the actuators described above with reference to FIG. Figures 5A-5C The button 422b described operates similarly. For example, in the distal or active position, the actuator 522b can enable electrical energy to be delivered to the guide wire deployed in the electrosurgical interface 522. In some embodiments, the actuator 522b can generate a signal that triggers the electrosurgical generator (e.g., generator 110) to deliver energy (e.g., voltage waveform) to the electrosurgical interface, which then delivers energy to the guide wire. In some embodiments, the actuator 522b can provide tactile feedback (e.g., vibration, click, etc.) to the user during operation, for example, when the actuator 522b moves to the position where energy is delivered to the guide wire. In some embodiments, the actuator 522b may not be a sliding actuator. For example, the actuator 522b can be a button that can be pressed to activate energy delivery, or another type of actuated component. In some embodiments, operating the actuator 522b can include multiple movements. For example, in order to activate energy delivery to the guide wire, it may be necessary to first translate the actuator 522b, then press to activate energy delivery. In some embodiments, the actuator 522b is spring-loaded such that the actuator 522b returns to an inactive position when the user does not apply force to the actuator 522b.

[0108] The housing 522a can be configured to be grasped by a user (e.g., a surgeon) during use. For example, the surgeon can hold the housing 522a with one hand while using his or her other hand to hold and move (e.g., distally advance and / or retract) a guidewire deployed within the electrosurgical interface. Figures 6A-6B As depicted in FIG, in some embodiments, the cable portion 542a can be positioned along the housing so as not to interfere with a user's grip on the housing 522a. Figure 6B As seen in FIG, cable portion 542a can be positioned toward the rear of housing 522a and can extend away from housing 522a at an angle. Similar to cable 442a, cable 522a can include a plug or connector 542b that can be plugged into or otherwise coupled to a generator (e.g., generator 110) for receiving energy from the generator and for sending signals to the generator (e.g., for triggering energy delivery). In some embodiments, the position of cable portion 542a can be reconfigurable to allow for a first configuration for left-handed users and a second configuration for right-handed users.

[0109] like Figure 6C As seen in FIG. 5 , the internal components and arrangement of electrosurgical interface 522 can be similar to electrosurgical interface 422. For example, electrosurgical interface 522 includes electrodes 548 (e.g., similar in structure and / or function to Figure 5C 3 ). The guidewire can include a conductive portion configured to be disposed in the conductive fluid within the lumen so that the energy delivered to the electrode by the generator can be received by the guidewire via the conductive fluid. The guidewire can have a conductive surface area that is coupled to the conductive core of the guidewire, which can carry energy to the distal tip of the guidewire, for example, for perforating through tissue. The guidewire can be received and extended through the electrosurgical interface 522 through port 522d. The electrosurgical interface 522 can also include an expander interface or coupler 522c that can be coupled to an expander or sheath (e.g., sheath 126 or expander 426).

[0110] As a reference Figures 3A-6CIn another embodiment, the electrosurgical interface can be configured to be coupled to the distal end of the guide wire, for example, via the physical attachment between electrical port and the guide wire. In such embodiments, the proximal end of the guide wire can be received in the electrosurgical interface and physically engaged with the electrode or other conductive components that are wired to the generator (for example, via electrical circuit system). The proximal end of the guide wire can include a conductive region so that energy (for example, RF current) can be delivered to its distal end via the guide wire, for example, for perforation through tissue. The movement of the guide wire relative to the electrosurgical interface can be more restricted than the above-mentioned sliding contact embodiment.

[0111] Figures 7A-7C An example of an electrosurgical interface 622 is depicted according to an embodiment, which can be configured to receive the proximal end of a guidewire, for example, to establish an electrical coupling between the guidewire and a generator (e.g., generator 110). The electrosurgical interface 622 can include components that are structurally and / or functionally similar to the generator. Figure 1 or similar components of other electrosurgical interfaces described herein. Figure 7A A top view of electrosurgical interface 622 is depicted. Figure 7B A top view of electrosurgical interface 622 is depicted showing the internal components of the electrosurgical interface. Figure 7C An electrosurgical device 620 (e.g., structurally and / or functionally similar to an electrosurgical device 622) is depicted according to an embodiment. Figure 1 120 in FIG. 1 ).

[0112] like Figure 7A As seen in FIG. 1 , the electrosurgical interface 622 includes a housing 622a (eg, functionally and / or structurally similar to a housing 622a). Figures 5A-5C ), button 622b (e.g., similar in function and / or structure to the housing 422a in FIG. Figures 5A-5C ) and cable 642a (e.g., similar in function and / or structure to button 422b in FIG. Figures 5A-5C 642a). Figure 7B As seen in FIG, electrosurgical interface 622 also includes a port or opening 622c and electrodes 648 disposed on a circuit board 644 that can be electrically coupled to a generator. Cable 642 is operably coupled to electrosurgical interface 622a via circuit 644 to provide electrical energy to the guidewire via electrodes 648.

[0113] Port 622c is configured to receive a guidewire (eg, functionally and / or structurally compatible with a guidewire). Figure 1622b) so that the guidewire can be physically engaged with the electrode 648. The electrosurgical interface 622 may include a coupling element (e.g., a clip, a fastener, etc.) that can be configured to be retained on the guidewire, for example, to maintain the guidewire in place within the port after it is received therein. When the guidewire is received within the port 622c and coupled to the electrode 648, the electrode 648 can be configured to deliver electrical energy to the guidewire in response to a user actuating the button 622b. Although Figures 7A-7C A button is depicted in FIG, but it can be appreciated that any type of actuator can be used to activate energy delivery. Similar to the sliding actuator described above with respect to the figures, actuation of the button can be configured to send a signal to the generator to trigger the generator to deliver energy to the guidewire.

[0114] Figure 7C An electrosurgical device 620 is depicted that includes a guide wire 624 (e.g., functionally and / or structurally similar to a guide wire 624). Figure 1 energy delivery element 124), dilator or sheath 626 (e.g., functionally and / or structurally similar to Figure 1 The guide wire 624 can be disposed within the expander 626 and the hub 628 and can move relative to the expander 626 and the hub 628. The proximal end of the guide wire 624 can be received in the electrosurgical interface 622. Figure 7C In the embodiment of the present invention, the tip 624a of the guidewire 624 is extended and deployed distally of the distal end of the dilator 626, so that the guidewire 624 forms a J-shape (or other atraumatic shape). In use, the guidewire can first be deployed in the dilator 626 in a straightened configuration and then extended to the distal side of the dilator 626 to expose the tip of the guidewire for delivering energy, for example, to perforate tissue.

[0115] System and equipment described herein avoid the disadvantage of physical contact between two sliding parts in sliding contact design by using a chamber full of fluid to establish electrical connection between electrosurgical generator and electrosurgical device.Electrosurgical guide wire can be positioned in the chamber full of fluid and be freely advanced or retracted.Utilize system and equipment described herein, electrosurgical guide wire can have unconstrained proximal end, and this allows operator to freely advance, retract or exchange guide wire, without any intermediate step, such as for example disconnect cable.Compared with the system that the proximal end of guide wire can be constrained (for example, clamped or clamped to connector), doctor can quickly remove them by retracting sheath, dilator or other instruments on guide wire, and exchange them for different instruments.This can produce improved workflow and possibly faster procedure time.In addition, doctor or other medical professional can activate energy delivery in aseptic environment by using activation mechanism.And, given the frictionless design (or substantially frictionless design) of the electrical connection between generator and electrosurgical device, doctor can rely on tactile feedback (for example, due to the behavior of guide wire tip) to assess when guide wire contacts with tissue surface. In the case of a transseptal perforation, this tactile feedback is important for the physician to confirm guidewire placement, monitor when perforation occurs, and / or monitor when unintended contact with the tissue surface may occur.

[0116] Figures 3A-3C Depicted are different views of an example electrosurgical interface 322 according to an embodiment. Electrosurgical interface 322 can be configured to transmit electrical energy from an electrosurgical generator (e.g., generator 110, 210) to the distal end of a conductive guidewire or other energy delivery element (e.g., energy delivery element 120, guidewire 224) for therapeutic purposes such as transseptal puncture. Electrosurgical interface 322 can be similar in structure and / or function to other electrosurgical interfaces described herein (e.g., electrosurgical interfaces 122, 222).

[0117] like Figure 3A As depicted in FIG, the electrosurgical interface 322 may include a fluid-filled chamber 344 that transmits electrosurgical energy from a cable 342 connected to a generator (not depicted) to a stationary conductive electrode 348 and a movable conductive element (e.g., energy delivery element 120, guidewire 220). The fluid-filled chamber 344 may include a thin layer of conductive fluid that conducts energy from the generator and the stationary electrode 348 to the movable conductive element. Thus, energy can be conducted from the generator to the distal tip of the movable conductive element (such as a guidewire).

[0118] The chamber 344 can have a shape that is easy to flush and fill with fluid without any bubbles being trapped in the chamber 344. For example, the chamber 344 can have a shape with rounded edges or corners to prevent bubbles from being trapped in the chamber. The conductive fluid used can be saline or other sterile conductive solution. In an embodiment, the conductive fluid is a 0.9% saline (NaCl) solution. Combined with a large static electrode surface area, the conductive fluid can provide an electrosurgical connection that does not increase (or does not significantly increase) the impedance of the circuit or increase the electrical load on the generator.

[0119] The stationary electrode 348 can have a flat printed circuit board construction, or can be a metal plate with gold, silver, steel, or copper conductors. Since the stationary electrode 348 contacts the patient's blood pool via a fluid path, the stationary electrode 348 should also be biocompatible. The stationary electrode 348 can be flat, such as Figures 3A-3C As depicted in , or alternatively, there may be a tubular design in which the movable conductive element is coaxial with the stationary electrode. For example, with a tubular design, the stationary electrode may be formed by a coil coaxial with the movable conductive element.

[0120] The movable conductive element (not depicted) can be an energy delivery element or a guide wire, for example, as described above with respect to Figure 1 and Figure 2 In some embodiments, the movable conductive element is a metal guidewire, wherein the conductive portion of the guidewire is positioned adjacent to a stationary electrode surrounded by a conductive fluid. The conductive portion of the guidewire can be a stainless steel profile or can be plated with an inert high-conductivity alloy (e.g., gold) to facilitate a low-impedance path from the electrosurgical generator. In some embodiments, an insulating coating can be located distally or proximal to the conductive portion of the guidewire that is located in the conductive fluid, for example, to provide electrical insulation along the rest of the guidewire.

[0121] In some embodiments, an electrosurgical generator (e.g., generators 110, 210) can be integrated with an electrosurgical device (e.g., electrosurgical device 120, 220). In such embodiments, the electrosurgical generator and device can include a handheld component, e.g., a handle assembly, that can house the generator. Figure 10 is a schematic diagram of a handheld electrosurgical system 1000 according to an embodiment. In some embodiments, the handheld electrosurgical system 1000 may include components that are structurally and / or functionally similar to other electrosurgical systems described herein (e.g., including Figure 1 The handheld electrosurgical system 1000 includes a housing 1001 that optionally includes a power source 1002 (e.g., similar in structure and / or function to the handheld electrosurgical system 1000). Figure 1 102), a generator 1010 (e.g., similar in structure and / or function to Figure 1generator 110) and an electrosurgical interface 1022 (e.g., similar in structure and / or function to the Figure 1 The handheld electrosurgical system 1000 also includes a return electrode 1130 (e.g., similar in structure and / or function to the electrosurgical interface 122 of the handheld electrosurgical system 1000) operably coupled to the generator 1010. Figure 1 130 ), and an energy delivery element 1024 operatively coupled to an energy delivery element 1124 (e.g., structurally and / or functionally similar to the return electrode 130 ). Figure 1 energy delivery element 124).

[0122] The housing 1001 can be an enclosure, container, or the like configured to house the power source 1002, the generator 1010, and the electrosurgical interface 1022. The housing 1001 can be in a form factor that can be held in the hand of a surgeon. The handheld electrosurgical system 1000 allows for a reduced system complexity because the number of independent components is reduced, thereby reducing complexity during operation. The handheld electrosurgical system 1000 also allows for a reduction in the number of support personnel required to use the system and reduces the number of wires, cables, and / or equipment on the treatment table. In some embodiments, the housing 1001 can be ergonomically shaped to facilitate use by medical professionals. In some embodiments, the housing 1001 can include a power source 1002 (e.g., a battery, etc.). Using a battery or similar power source 1002 reduces the risk of unexpected power-related issues from the power source 1002. In some embodiments, the power source 1002 is a reusable, rechargeable battery pack. In some embodiments, the housing 1001 is electrically coupled to an external power source 1002 that provides power to the electrosurgical system 1000. In some embodiments, the housing 1001 can include buttons, a display, etc. to operate the generator 1010. In some embodiments, the handheld housing 1001 can be sterilized and reused.

[0123] Energy delivery element 1024 is configured to be operably coupled to electrosurgical interface 1022. Housing 1001 can be configured to be coupled to an end of energy delivery element 1024 or energy delivery element 1024 can be configured to operably slide through housing 1001. Return electrode 1030 is configured to be operably connected to generator 1010 and the patient.

[0124] Energy delivery element or guidewire

[0125] Figures 8A-8B A guidewire 724 of an electrosurgical device (eg, electrosurgical devices 100 , 200 , 400 ) is depicted according to an embodiment. Figure 8A A side view of the guidewire 724 is provided with breaks to better illustrate the details of the various components of the guidewire 724. Figure 8B and Figure 8C A perspective view of a guidewire 724 within a dilator 726 is depicted, the dilator forming an opening and advancing through tissue 750. The guidewire 724 may be functionally and / or structurally similar to Figure 1 energy delivery element 124 and / or Figure 4 Similar to the guide wire 424.

[0126] like Figure 8A As depicted in FIG, an embodiment of the guide wire 724 includes a tip 724a, a distal curved portion 724c, a distal segment 724b, and a proximal segment 724d. The guide wire 724 is formed of stainless steel, having a tapered core wire and a distal coil welded at the tip 724a and a proximal termination (e.g., the distal end of the proximal segment 724d). Alternatively, the core wire can be formed of a nickel-titanium alloy. The guide wire 724 is formed of a biocompatible and sterile material.

[0127] The distal segment 724b and / or the proximal segment 724d conduct energy (e.g., from an electrosurgical interface) when in use. The distal segment 724b can be conductive along its length at or near the proximal end of the distal segment 724b. The proximal segment 724d can have an exposed conductive area that is configured to interface with an electrode (e.g., an electrosurgical interface). Figure 5B 448 ). When energized, the proximal segment 724d conducts this energy to the distal tip 724a of the guidewire. In some embodiments, the proximal segment 724d can be partially or fully insulated so that it can be held during use. For example, the proximal portion of the proximal segment 724d can be covered with an insulating layer. The insulator can prevent current from flowing through the wire and into the physician's hand. The insulating coating can be, for example, polytetrafluoroethylene, perfluoroalkoxy alkane, fluorinated ethylene propylene copolymer, polyimide, epoxy resin, ceramic, nylon and / or a composite of insulating materials. The proximal segment 724d is rigid to facilitate the exchange of large-caliber sheaths through tortuous patient anatomy. The distal segment 724b and / or the proximal segment 724d (or portions thereof) can be gold-plated on a stainless steel core to improve electrical conductivity, including thermal conductivity. This conductivity is beneficial for conducting heat away from the distal tip of the guidewire, for example, to prevent the distal tip of the guidewire from overheating.In some embodiments, the core of the guidewire 724 can be coated with tungsten or other conductive materials.

[0128] The distal segment 724b may be less rigid than the proximal segment 724d. In some embodiments, a portion of the distal segment 724b may be coated with a non-conductive or insulating coating, or the distal segment 427b may not be insulated. For example, as described in reference Figure 1As described, the distal segment 724b can have an insulating collar that surrounds a short section of the guidewire near or adjacent to the distal tip of the guidewire. In some embodiments, the length of the distal collar can be between about 2 mm and about 10 mm, including all subranges and values ​​therebetween. The distal end of the distal segment 724b includes a curved portion 724c. The curved portion 724b is formed of a shape memory material. The curved portion 724b can be J-shaped, such as Figure 8A , but other shapes are possible, including straight and / or other curved or spiral shapes (e.g., pigtail, coil, etc.). Figure 8A In the embodiment of the present invention, the J-shape of guide wire 724 is anti-damage because it is not damaged when navigating through the patient's anatomical structure. Guide wire 724 can maintain its J-shape when it is unconstrained and is navigated through the patient's anatomical structure to reach the target tissue. However, in order to apply energy to tissue, guide wire 724 can be constrained to a straighter configuration, for example, so that the distal tip 724a of guide wire is positioned to apply energy to tissue and pierce tissue. For example, when guide wire 724 is retracted in a sheath or dilator (for example, sheath 126), guide wire 724 can be constrained to a straight or substantially straight structure. Tip 724a is the conductive and / or non-insulated portion of distal segment 724b. Tip 724 can be energized to deliver energy (for example, RF energy) to tissue to create a perforation or opening; for example, by activating electrosurgical interface 122 to transfer energy from generator 110 to the exposed area of ​​the wire slidably positioned therethrough. As discussed above, the guidewire 724 may again assume a J-shape if extended beyond the perforation in the target tissue.

[0129] Figure 8B and Figure 8C The guidewire 724 is shown in use. The guidewire 724 and sheath 126 can be advanced through the patient's vasculature to the target site. Figure 8B In the embodiment, the guide wire 724 is inserted into the dilator 726 (e.g., functionally and / or structurally similar to the dilator 726). Figure 1 The sheath 126 and / or other sheaths and dilators described herein are similar) such that only the tip 724a extends from the dilator 726. In this configuration, the tip 724a is positioned in line (or approximately in line) with the longitudinal axis of the dilator 726. In some applications (e.g., when traversing a septum), the tip 724a can be pressed against the tissue 750, such as Figure 8B. This can be used as part of the tenting of the tissue. Upon activation, RF energy is transmitted from the generator to the tip 724a and heats the tissue 750 at the contact. Heating the tissue 750 causes dehydration, protein denaturation, and loss of the mechanical integrity of the tissue. The expander 726 can then be advanced to the contact to form a puncture in the tissue 750, thereby allowing the guidewire 724 to be advanced into the puncture. Once the puncture is formed, the energy input is terminated.

[0130] exist Figure 8C 8 , the dilator 726 can have a conical to conical tip such that as the dilator 726 is pushed further into the puncture 752, it expands or dilates the puncture. An auxiliary treatment device (e.g., an ablation catheter, a sheath, etc.) can be advanced through the expanded puncture, optionally along the guide wire 724 after the dilator 726 is removed. Thus, the guide wire 724 acts as both an energy delivery device and a mechanism for guiding additional surgical instruments or medical devices.

[0131] Figure 9A and Figure 9B An electrosurgical device such as Figure 1 Different examples (e.g., structurally and / or functionally similar) of guidewires (924a and 924b) for electrosurgical devices 120 of the present invention are provided. Figure 1 1 and 12. The energy delivery element 124 of the present invention and other guidewires described herein are similar. Guidewires 924a and 924b include two segments, one of which is conductive (e.g., metal) and the other segment is non-conductive at least on the outside (e.g., having an insulating coating). Different segments of guidewires 924a and 924b can be different colors, for example, to identify the guidewires as specialized guidewires (such as, for example, a guidewire for forming a puncture) and / or to help an operator distinguish between different portions of guidewires 924a and 924b. The resulting two-tone design allows for quick identification by a physician during a procedure.

[0132] Guidewires 924a and 924b include proximal segments 924d and 924f, connected at transition points A and B, respectively, and distal segments 924c and 924e. Distal segments 924c and 924e are metallic or have a metallic layer and provide a continuous conductor from transition points A and B, respectively, to the distal end of the guidewire (e.g., for performing electrosurgery). Distal segments 924c and 924e can be gold-plated on stainless steel or another base metal (such as tungsten). The outer layer of distal segments 924c and 924e can cover manufacturing marks caused by welding, heat setting, or molding, thereby producing a smooth and consistent surface finish. Proximal segments 924d and 924f (or at least portions thereof) are coated with an insulating coating. The coating can be PTFE, FEP, polyimide, epoxy, or nylon. The polymer can be extruded, reflowed, or applied by coating. The coating can be a single uniform color, a repeated pattern, or can be a plurality of segments of different lengths including different colors.

[0133] like Figure 9A and Figure 9B As shown in , the ratio of the length of the distal segment to the length of the proximal segment can vary across different guidewires. In some embodiments, the distal segment forms at least about 20% and no more than 80% of the total length of the guidewire. Figure 9A In the guidewire 924a, the distal segment 924c is longer than the proximal segment 924d. Figure 9B In the guidewire 924b, the proximal segment 924f is longer than the distal segment 924e. In some embodiments, the lengths of the distal segment and the proximal segment can be approximately equal.

[0134] In embodiments, a guidewire or other energy delivery element as described herein can be formed of multiple layers. The center of the guidewire can be a conductive core wire that can be configured to carry current from the electrosurgical interface to the distal tip of the guidewire. One or more additional layers (e.g., coatings, coils, etc.) can surround the core wire. In order to enable a conductive path from the outer layer of the guidewire to the core wire, one or more conductive paths can be formed between the core wire and the outer layer of the guidewire. Referring generally to Figure 11A and Figure 11B , shows an example of a guidewire (1124a and 1124b). The guidewires 1124a and 1124b can be coated with an electrical insulator 1125a and 1125b, respectively. In some embodiments, the insulator is a polymer. A portion of the insulating coating 1125a and 1125b of the guidewires 1124a and 1124b can be missing (e.g., removed using a laser or mechanical cutting instrument) to expose the conductive element to allow electrical conductivity to the conductive element. For example, the exposed area can be a plurality of openings (e.g., a plurality of openings) in the coating of the guidewire 1124a. Figure 11A ) or a spiral cut in the coating of the guidewire 1124b (as seen in Figure 11B), but other cutting patterns may also be used. For redundancy and to increase the current path to the underlying conductive element, the exposed area creates one or more conductive areas for the underlying conductive element. In some embodiments, after exposing portions of the coating, the coating may be coated with a conductive coating (e.g., a metal coating). In some embodiments, the exposed area can be used to separate the core wire of the guidewire from the electrosurgical interface (such as, for example, Figure 1 In some embodiments, the exposed area can be used to create a larger conductive surface area or active electrode area for the guidewire, which can be used to reduce the current density at the tip of the guidewire by distributing the charge or current over a larger conductive surface area of ​​the guidewire. Figure 40 and Figure 41 Further details of such guidewires are described.

[0135] Figures 15A-15B Describes the accidental injury caused by electrosurgical equipment entering the heart. Figure 15A and Figure 15B As seen in , the depicted heart includes an accidental lesion 1590 in the left atrium. Figure 15A A diagram of a lesion 1590 formed by a guidewire of a transseptal device or other electrosurgical device 1520 is depicted. The guidewire of the electrosurgical device 1520 may contact the wall of the left atrium after being deployed from the sheath, thereby causing the lesion 1590. The systems, devices, and methods described herein are configured to reduce the likelihood of forming lesions such as lesion 1590. For example, below with reference to Figure 13 and Figure 14 The described methods can be configured to reduce the RF output of the electrosurgical device when it is not desired. Additionally or alternatively, as described in the following figures, the construction and design of the guidewire or energy delivery element can reduce the risk of lesion formation, for example, by reducing the current density as the guidewire extends distally from the dilator or outer sheath.

[0136] In some embodiments, the guidewire or energy delivery element of the electrosurgical system described herein can be configured to have a lower current density when extended distally beyond the septum, while maintaining a higher current density when piercing the septum. In particular, the guidewire described herein can have a longer conductive length so that when the guidewire extends into the blood pool outside the septum, the longer conductive length of the guidewire disperses the current density along the length of the guidewire. This then reduces the current density at any point along the guidewire, thereby reducing the risk of myocardial damage when the guidewire contacts the heart wall.

[0137] For example, the guidewire can include a first distal conductive portion having a length of approximately 1.0 mm, a first insulating region having a length of approximately 0.5 mm, and a second conductive region having a length of approximately 12.0 cm. The first conductive portion and the second conductive portion can include a metal structure, including a coil (e.g., a stainless steel coil, a tungsten coil, etc.), and the insulating region can include a polymer sheath material, such as a polyolefin, polyethylene terephthalate, etc. When the first conductive region extends less than 10 mm beyond the dilator, the tip of the guidewire can be configured to have a current density of approximately 25 A / cm2 to approximately 250 A / cm2. Additionally, when the conductive region extends less than 10 mm beyond the dilator, the conductive region of the guidewire can be configured to have a current density of less than 60 A / cm2. For example, when the distal tip is within 0.5 mm of the sheath, the current density can be approximately 60 A / cm2. Additionally, when the tip extends approximately 10 mm beyond the sheath, the first conductive portion and the second conductive portion can be configured to have a current density of less than approximately 25 A / cm2. 2 current density.

[0138] refer to Figure 16-27C , shows a comparison between the operation of two electrosurgical devices (Device 1 and Device 2). As shown, the two electrosurgical devices operate differently, for example, due to the different designs of their guidewires. Device 1 represents an electrosurgical device that includes a guidewire similar to the embodiments of energy delivery elements and guidewires described herein, while Device 2 represents a device that includes an existing guidewire that can be used in transseptal procedures. Figure 16 and Figure 17 Further details of the construction of the guidewires of Devices 1 and 2 are provided.

[0139] Figure 16 Depicts an apparatus 1 according to an embodiment (eg functionally and / or structurally similar to Figure 1 The cross section of the electrosurgical device 120 is similar to that of the electrosurgical device 120 of FIG. 1 , which includes a guide wire or energy delivery element and a dilator. The energy delivery element can be similar in function and / or structure to other energy delivery elements or guide wires described herein, and the dilator can be similar in function and / or structure to other sheaths or dilators described herein. Figure 16 As seen in FIG, the energy delivery element includes a tip, a core, a coating (e.g., tungsten) surrounding the core, inner and outer coils (e.g., formed of tungsten), and a gold coating in the coils and tip. As described above, the energy delivery element can include a larger active electrode area or a conductive outer surface. In use, the energy delivery device can be flushed with a fluid (such as saline). The energy delivery element can be deployed within the expander, and a layer of blood or fluid can be deployed between the energy delivery element and the expander.

[0140] Figure 17 A cross-section of device 2 is depicted that includes a guidewire or energy delivery element and an expander. The energy delivery element includes a tip, a core, and a PET coating (e.g., an insulating coating) that covers a conductive portion of the guidewire proximal to the tip. The energy delivery element can be deployed within the expander, and a layer of blood or fluid can be deployed between the energy delivery element and the expander. The main difference between the guidewire of device 1 and the guidewire of device 2 is that an insulating coating is added to the guidewire of device 2 that covers all areas of the guidewire except the tip or distal portion of the guidewire. By adding this insulating coating, the only exposed conductive portion of the guidewire is the tip of the guidewire. Therefore, any energy delivered to the guidewire of device 2 is concentrated at the tip, as shown in FIG. Figure 18-27C and Figure 36-38B This is reflected in the operation of the device shown in FIG.

[0141] Figure 16-27C and Figure 36-38B Operation of the guidewires of Device 1 and Device 2 under simulated conditions is depicted. Simulated conditions are used to demonstrate the differences in the operation of the guidewires of Device 1 and Device 2. While certain values ​​for current density, temperature, and other parameters may be shown in these figures, it will be appreciated that other values ​​may exist during actual, non-simulated operation of the devices. Figure 18 Depicts the guidewire as it is retracted in the dilator (e.g., at an insertion depth of -5 mm from the septal wall). Figure 16 and Figure 17 The current density and temperature of the electrosurgical device. The insertion depth reflects the distance that the tips of the guide wires of Device 1 and Device 2 are distal to the top surface of the septum. Therefore, a negative insertion depth indicates that the tips of the guide wires of Device 1 and Device 2 are proximal to the top surface of the septum. Figure 18 As seen in , when deployed within the expander (e.g., after retraction), Device 1 and Device 2 have similar current density and thermal characteristics. For example, the maximum temperature of Device 1 is 44.6°C, and the maximum temperature of Device 2 is 44.3°C.

[0142] Figure 19 Depicts the guidewire as it extends a short distance from the dilator and engages the septum (insertion depth into the septal wall is 0.5 mm). Figure 16 and Figure 17 The current density and temperature of electrosurgical equipment. Figure 19 As can be seen in Figure 2, although Device 1 has a slightly lower maximum temperature than Device 2 (e.g., 99.7°C vs. 101°C), both guidewires deliver comparable levels of energy for perforating or piercing the septum. Furthermore, given that the tip of the guidewire of Device 1 has a slightly wider geometry compared to the tip of the guidewire of Device 2, the guidewire of Device 1 generates a wider current density distribution at the septum, which can further facilitate piercing the septum. Figure 36The current density distribution and maximum current of the guidewires of devices 1 and 2 are depicted. Figure 36 As shown in Figure 1, the maximum current density of device 1 is about 39.1 A / cm 2 , while the maximum current density of device 2 is about 54.6A / cm 2 .

[0143] Figure 20 Depicts the guidewire as it extends beyond the dilator and rests against the heart wall (e.g., 21.5 mm insertion depth from the septal wall). Figure 16 and Figure 17 As mentioned above, the insertion depth reflects the distance that the tips of the guidewires of Device 1 and Device 2 are distal to the proximal surface of the septum. Figure 20 As can be seen in Figure 2, the current for Device 1 is more distributed across its exposed length than for Device 2. Therefore, the current density at the heart wall for Device 1 is significantly lower than that for Device 2. Figure 37 , which shows that the guide wire of device 1 has 8.45A / cm 2 The maximum current density of the device 2 guidewire is 55.5A / cm at the heart wall. 2 The lower current density at the heart wall for Device 1 is due to the longer exposed conductive length of Device 1, which serves to disperse or dissipate the energy delivered to the tip of the guidewire. In contrast, Device 2 has a current density concentrated at its tip because its insulating coating includes a conductive portion only at the tip. The lower current density indicates that Device 1 is less likely to cause undesirable tissue damage than Device 2. Moreover, the temperature of Device 1 at its tip is significantly lower than that of Device 2 at its tip. Specifically, Figure 20 The simulation results in

[15] show that the maximum temperature of device 1 is 39.8°C and the maximum temperature of device 2 is 98.5°C. Therefore, the user of device 1 is less likely to damage the heart wall than the user of device 2. The lower temperature of device 1 compared to device 2 may be due to heat being drawn or dissipated across a greater length of the device. As previously mentioned, Figure 16As described, the device 1 may include a gold coating that may be configured to conduct heat away from the distal tip of the device. As a result, the temperature at the tip of the device 1 is lower, and therefore, the device 1 is less likely to cause unintended damage or irritation to tissue surfaces (including, for example, the wall of the heart). While gold is provided as an example of a material that can conduct heat away from the tip of the device 1, it will be appreciated that any other type of thermal conductor may be used as a coating, layer, or other component of the device 1 (or any other energy delivery element or guidewire described herein) to reduce heat at the tip of the device. For example, a material such as diamond (e.g., applied using chemical vapor deposition (CVD)) may be applied to one or more components of the energy delivery elements / guidewires described herein to provide electrical insulation and / or reduce the temperature at the tip of such components.

[0144] Figure 21 The phenomenon of distributed current density can be further seen in Figure 2, which depicts the current density distribution when the guidewire is extended from the dilator and located in the blood pool (e.g., the left atrium). Figure 16 and Figure 17 The current density and temperature of electrosurgical equipment. Figure 21 As seen in Figure 1, the current density generated by device 1 is distributed along the length of the guidewire, while the current density generated by device 2 is concentrated around the tip of the guidewire. As mentioned above, this concentration can be problematic because it can cause damage if it contacts the heart wall, such as Figure 15A and Figure 15B The distributed current density and lower current density values ​​generated by device 1 are less likely to cause damage because the current density is distributed along the length of the guidewire. Figure 37 As shown, the guidewire of device 1 has a current of 8.14 A / cm in the blood pool. 2 The maximum current density of the device 2 is 44.5A / cm in the blood pool. 2 Furthermore, the temperature of device 1 at its tip is lower than the temperature of device 2 at its tip. Specifically, Figure 21 The simulation results in Figure 3 show that the maximum temperature of device 1 is 37.5° C. and the maximum temperature of device 2 is 42.5° C. While the blood pool helps dissipate the heat accumulated at the tips of devices 1 and 2, the additional gold coating of device 1, which can help draw heat away from the tip, further helps to remove heat from the tip of device 1.

[0145] like Figure 37 As shown in , the maximum current density at both the heart wall and in the blood pool for Device 1 is significantly less than that for Device 2. As mentioned above, this difference is due to Device 1 allowing the current to dissipate along the length of the guidewire, rather than concentrating the current at the tip of the guidewire as in Device 2.

[0146] Figures 38A-38B The maximum current density of the guidewires of Devices 1 and 2 is plotted when the guidewires are deployed against the septum (ID=0.5, with myocardium), inserted through the septum and deployed in the blood pool (ID=21.5, without myocardium), and deployed against the heart wall (ID=21.5, with myocardium). As shown again in these figures, Devices 1 and 2 can have a sufficiently high maximum current density at the septum to allow them to pierce the septum; however, Device 1 has a significantly lower maximum current density after penetrating the septum compared to Device 2. The lower current density at the heart wall and in the blood pool reduces the likelihood of inadvertent lesions.

[0147] Figure 22 The temperature of the septum and guidewire tip is plotted over time for devices 1 and 2 at an insertion depth of 0.5 mm (i.e., when the tip engages the septum wall). Figure 22 As can be seen in Figure 2, the temperature at the diaphragm of both Devices 1 and 2 is approximately 100°C. However, the tip temperature of Device 1 is lower than the tip temperature of Device 2, indicating that the guidewire of Device 1 dissipates heat more effectively than the guidewire of Device 2. Figure 16 As shown in FIG, the guide wire of device 1 may include a gold plating. Gold is an effective thermal conductor and thus may help heat dissipate or be drawn away from the tip of the guide wire. While gold is provided as an example of an effective thermal conductor, other thermally conductive materials may also be used, such as diamond, other metals, etc.

[0148] Figures 23A-23C The following diagrams depict the insertion depth of the guide wire at the septum of 0.5 mm. Figure 16 and Figure 17 The terminal voltage, terminal current and terminal impedance curve of the electrosurgical device. Figures 23A-23C As can be seen in the diagram, when powered on, Device 1 has a smaller terminal voltage, a larger terminal current, and a smaller terminal impedance than Device 2. Although there is a difference in terminal voltage between Device 1 and Device 2, the difference is not significant at an insertion depth of 0.5 mm, allowing Device 1 to be effective for penetrating tissue.

[0149] Figure 24A and Figure 24B Depicts the guidewire inserted through the septum and positioned at the heart wall (with myocardium) or in the blood pool (without myocardium) at a depth of 21.1 mm. Figure 16 and Figure 17 As described above, the insertion depth reflects the distance the guidewires of devices 1 and 2 are inserted into the top surface of the septum. Figure 24A The temperature of the myocardium and the tip of the guidewire of Device 1 and Device 2 when the guidewire contacts the myocardium is depicted. Figure 24AAs can be seen in Figure 2, the temperature at the myocardium and at the tip of the guidewire of Device 1 is lower than the temperature at the myocardium and at the tip of the guidewire of Device 2. The lower temperature again reflects that Device 1 is better configured to dissipate heat. Therefore, Device 1 is less likely to cause myocardial damage than Device 2. The heat dissipation effect of Device 1 can also be seen in Figure 24B As can be seen in FIG, the figure shows the temperature of the blood pool and the tip of the guide wire in the blood pool. Figure 24B As can be seen in FIG, the temperature of the guidewire tip and the blood pool in device 2 are both higher than those in device 1, indicating that device 1 is better at dissipating heat.

[0150] Figures 25A-25C Depicts the guidewire inserted through the septum and located in the heart wall (with myocardium) or in the blood pool (without myocardium) at a depth of 21.1 mm. Figure 16 and Figure 17 Graph of the terminal voltage of an electrosurgical device. Figures 26A-26C Depicts the guidewire inserted through the septum and located in the heart wall (with myocardium) or in the blood pool (without myocardium) at a depth of 21.1 mm. Figure 16 and Figure 17 Graph of the terminal current of an electrosurgical device. Figures 27A-27C Depicts the guidewire inserted through the septum and located in the heart wall (with myocardium) or in the blood pool (without myocardium) at a depth of 21.1 mm. Figure 16 and Figure 17 Graphs of the terminal impedance of electrosurgical devices of FIG1 and FIG2 are provided. As depicted in these graphs, the terminal voltage at the tip of the guidewire of Device 1 is significantly lower than that at the tip of the guidewire of Device 2, and is therefore less likely to cause damage or injury to the myocardium or other tissue surfaces. The impedance of the guidewire of Device 1 is also generally lower than that of the guidewire of Device 2, as more conductive area of ​​the guidewire is exposed, allowing charge to dissipate along a longer extent of the guidewire.

[0151] In some embodiments, systems, devices, and methods according to embodiments disclosed herein can be configured to monitor the impedance of a guidewire or energy delivery element. Figure 23C and Figures 27A-27C As shown in , once the guidewire is deployed in the blood pool or at the myocardium (heart wall), the impedance of the guidewire decreases. This decrease in impedance is due to the larger exposed conductive surface area of ​​the guidewire. Therefore, monitoring the decrease in impedance (e.g., using a controller such as processor 114, as described above) can allow the system to adjust the delivered voltage, for example, to avoid high current values ​​and thereby avoid current leakage.

[0152] In some embodiments, the electrosurgical devices described herein may include a guidewire with an insulating loop. Figures 28A-28B Depicted is an example guidewire 2924 (e.g., functionally and / or structurally similar to a Figure 1 124 ). FIG. 125 illustrates a cross-sectional view of a guidewire (similar to an energy delivery element 124 of FIG. 125 ) having a tip 2924a with an insulating collar 2924e. Guidewire 2924 includes tip 2924a, coil 2924b, insulating collar 2924e, fluid 2924f, and core 2924g. In this embodiment, guidewire 2924 is symmetrical about a central axis and has an insulating coating proximal to coil 2924b.

[0153] Tip 2924a is electrically coupled to core 2924g, which is operably connected to a generator, optionally via an electrosurgical interface such as Figure 1 The core 2924g transfers energy to the tip 2924a so that the tip 2924a can engage and deliver energy to the tissue. The tip 2924a defines a tip width 2924c and a tip length D3. In some embodiments, the length D3 can be between about 0.5 and about 2 mm, including all subranges and values ​​therebetween. In some embodiments, the tip width 2924c is configured to fit within a sheath (such as Figure 1 The sheath 126 is provided and delivers the desired amount of energy to the tissue. Proximal to the tip 2924a, the core 2924g is surrounded by a fluid 2924f. Figure 28B As seen in FIG. 2 , the fluid 2924f may comprise saline. During operation, the fluid may comprise a mixture of blood and saline. The fluid 2924f is surrounded by the coil 2924b. In some embodiments, the coil 2924b is formed of stainless steel. Figure 28B As seen in FIG, the tip 2924a of the coil 2924b can be coated with a conductive coating. In some embodiments, the conductive coating can include gold, tungsten, tantalum, etc.

[0154] In some embodiments, a portion of the coil 2924b is covered with an insulating collar 2924e. The insulating collar 2924e is flush with the other portions of the coil 2924b. The insulating collar 2924e can be flush with the coil 2924b by compressing and / or stretching the coil 2924b (e.g., by deploying it on the stretched portion of the coil 2924b, etc.). The insulating collar 2924e can start along the coil 2924b at a distance D1 from the distal end of the guidewire 2924. In some embodiments, the length D1 can be between approximately 0.5 mm and approximately 3 mm from the distal end of the guidewire, including all sub-ranges and values ​​therebetween, for example, between approximately 1 mm and approximately 2 mm. The insulating collar 2924e has a length D2. In some embodiments, the length D2 can be between approximately 2 mm and approximately 10 mm, including all sub-ranges and values ​​therebetween, for example, between approximately 4 mm and approximately 6 mm. The collar 2924e can have a length that allows the current density at the distal end of the guidewire to remain high within the short distance necessary to ensure penetration of the septum (e.g., less than approximately 10 mm), but not so long that the current density at the distal end decreases when the guidewire is inserted beyond the septum and into the blood pool of the left atrium. In some embodiments, the insulating collar 2924e is formed from a polymer, ceramic, or thermoplastic (e.g., PEBAC, Grilamid, PET, PTFE, FEP, PEEK, etc.). In some embodiments, the insulating collar 2924e can be applied via chemical vapor deposition (CVD). For example, a diamond layer can be applied to the coil 2924b using CVD to form the insulating collar 2924e. In some embodiments, the insulating collar 2924e is configured to harden the distal end of the guidewire 2924. In some embodiments, the guidewire 2924 is sufficiently strong to provide a puncture force of approximately 0.1 to 5 Newtons. The insulating collar 2924e defines a thickness Ti. Optionally, the thickness Ti can be constant across the entire portion of the coil 2924b covered by the insulating collar 2924e. In some embodiments, the thickness Ti is greater than a predefined minimum thickness corresponding to the thickness required to prevent dielectric breakdown. In some embodiments, the insulating collar can have a thickness desired to provide a predetermined stiffness or flexibility of the guidewire 2924.

[0155] Figure 29 An electrosurgical device (device 3) is depicted in engagement with a septum according to an embodiment. Device 3 includes an insulating collar formed of an insulating material (eg, a 5 mm long PET collar) that is deployed over a portion of the device's guidewire proximal to the distal tip. Figure 29 Electrosurgical devices can be used in other ways Figure 16 Similar to electrosurgical devices. For example, Figure 29The electrosurgical device of can include a tip, a core, inner and outer coils (eg, formed of tungsten), and a gold coating. In use, the energy delivery device can be flushed with a fluid (such as saline).

[0156] like Figure 16 The device 1 and device 3 depicted in the drawings are examples of energy delivery elements or guidewires described herein and, therefore, can be similar in structure and / or function to other energy delivery elements or guidewires described herein. Device 3 can operate similarly to device 1 under most conditions, but due to the addition of an insulating collar, device 3 can exhibit different operating behavior from device 1 when the guidewires of both devices extend a short distance from the dilator. In particular, the guidewires of device 1 and device 3 can operate similarly to each other when the distance the guidewires of both devices extend from the dilator is less than approximately 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm (including any subranges or values ​​therebetween). When the guidewires extend these extremely short distances from the dilator, the exposed conductive surface area of ​​each guidewire can be small, and the current density at the tip of the guidewire of each device can be high and sufficient to pierce tissue (e.g., a septum). However, when the guidewires extend a greater distance from the dilator, the two devices can exhibit different behavior. In some embodiments, it may be desirable or necessary to extend the guidewire further from the sheath or dilator (e.g., if the dilator is not in perpendicular contact with the tissue). Device 1 without the insulating collar will have more conductive surface area that increases as it extends out of the dilator than device 3 with the insulating collar. Thus, at these initial short distances (e.g., less than about 10 mm, about 9 mm, about 8 mm, about 7 mm, about 6 mm, about 5 mm, about 4 mm, about 3 mm, or about 2 mm, including all subranges and values ​​therebetween), the current density of device 1 can drop more than the current density of device 3. Thus, for distances between about 1 mm and about 10 mm, the insulating collar can help maintain the current density at the tip of the guidewire of device 3 at higher displacement values, thereby allowing device 3 to still be able to deliver enough energy to pierce tissue (e.g., a septum). The following figures demonstrate these differences between devices 1 and 3.

[0157] Figures 30A-30C and Figures 39-41 B provides a comparison of the operation of Device 1 under simulated conditions with the operation of Device 3. Simulated conditions were used to demonstrate the differences in the operation of the guidewires of Devices 1 and 3. Figure 30A The behavior of the two devices is depicted when the guidewires are located at the septum and have been extended a short distance (e.g., about 0.4 inches or about 10 mm) from the dilator. For ease of illustration, the short distance that the two guidewires extend from the dilator is intentionally set to fully expose the loop along with one or more conductive portions of the guidewires. Figure 30BDepicts the heart wall with the guidewire positioned at the heart wall and the guidewire extended from the dilator. Figure 30A The behavior of the two devices at longer distances. And Figure 30C Describes the situation when the guidewire is in the blood pool and Figure 30A The behavior of the two devices was compared when the dilator was extended for a longer distance.

[0158] like Figure 30A As seen in Figure 1 , when the guidewire of device 1 is extended approximately 10 mm from the dilator, the current density has been distributed across the length of the guidewire, and therefore the energy at the tip has dropped to a lower value. In contrast, when the guidewire of device 3 is extended approximately 10 mm from the dilator (e.g., enough to expose the insulating collar), its tip has a higher current density due to the insulating collar. The insulating collar prevents current from dissipating in the portion of the guidewire it covers, thereby reducing the drop in current density at the tip as the guidewire is extended from the dilator. This can help prevent the guidewire from losing excessive energy at its tip as it extends from the dilator (at least for short distances). Therefore, the tip of the guidewire can effectively pierce the septum before the guidewire extends a certain distance from the dilator. This distance can be less than approximately 10 mm, less than approximately 15 mm, or less than approximately 20 mm, including all subranges and values ​​therebetween. This can allow device 3 to be configured to pierce the septum over a greater range of guidewire extension distances. After penetrating the septum, the higher current density of device 3 also decreases, reducing the likelihood of inadvertent injury. Due to the collar, the maximum temperature of device 3 (60.8°C) was slightly higher than that of device 1 (50.9°C); however, this temperature increase did not affect the operation of the devices. The temperatures of both guidewires remained below those that would cause undesirable consequences such as clotting or burning.

[0159] When the guide wire of the device 3 is further extended out of the dilator, e.g. Figure 30B and Figure 30C As shown in , the current density at the tip of the guidewire also decreases when located at the heart wall or in the blood pool outside the septum, similar to the case of device 1. In other words, similar to the guidewire of device 1, as the guidewire of device 3 extends further out of the dilator, the conductive surface area of ​​the guidewire increases sufficiently that the current density at the tip of the guidewire also decreases to a level that is less likely to cause damage at the heart wall. Therefore, devices 1 and 3 operate similarly to each other as their guidewires extend beyond the septum and expose a longer conductive surface area of ​​the guidewire. Figures 30B-30C As shown in , the temperature profiles of the two guidewires at the heart wall or in the blood pool can be similar. In particular, the maximum temperature of device 1 at the heart wall is 39.8°C and the maximum temperature of device 3 at the heart wall is 41.5°C. The maximum temperature of device 1 in the blood pool is 37.4°C and the maximum temperature of device 3 in the blood pool is 37.4°C. Figure 39As shown in Figure 3, the maximum current density of device 3 has decreased, but is still higher than that of device 1. At the heart wall, the maximum current density of device 1 is 3.52 A / cm 2 And the maximum current density of device 3 is 49.8A / cm 2 In the blood pool, the maximum current density of device 1 is 3.40A / cm 2 And the maximum current density of device 3 is 61.1A / cm 2 .

[0160] Overall reference Figures 31A-33 , showing various embodiments of deploying insulating collars and the like. The insulating collars may be similar in function to Figures 28A-29 The insulating collar can be used to form Figures 28A-29 The insulating collar is similar to the insulating collar. Figures 31A-33 The insulating collar can be used with a guide wire (such as Figure 1 or any other guidewire described herein).

[0161] Figure 31A An example of forming an insulating loop by first adding an insulating region 3224b to the coil wire 3224a is depicted. After the insulating region 3224b is located on the coil wire 3224a, the coil wire 3224a can be wrapped around the core or mandrel of the guidewire to form a coil. The formation of the coil can be Figure 31B As seen in FIG, where coil wire 3224a is wound around mandrel 3224c to form a coil. The coil can then be placed over the core of the guide wire and welded to the core of the guide wire. Figure 31B As shown in , the resulting insulating region can be used as an insulating collar for a guidewire. Figure 32 An example of an insulating collar 3324b on a guidewire 3324 is depicted in accordance with an embodiment. Figure 32 The insulating collar 3324b is a solid portion (e.g., a solid ring) adjacent to the tip 3324a of the guidewire 3324. The insulating collar 3324b can be disposed over the core 3324d of the guidewire, which is coupled to the tip 3324a. The insulating collar 3324b can be coupled to the coil 3324c at its proximal end. In some embodiments, the coil 324c is welded, bonded, etc. to the insulating collar 3324b. Figure 33 An example of an insulating loop implemented as coil 3424b on a guidewire 3424 according to an embodiment is depicted. Coil 3424b may be formed of an insulating material or a material with poor conductivity, and is wound around a core wire 3424d. Coil 3424b is located between conductive coil 3424c and tip 3424a, and provides an insulating portion of the guidewire 3424 near tip 3424a.

[0162] Figure 34 Another example of a guidewire 3524 with an insulating collar 3524c is depicted in accordance with an embodiment. The guidewire 3524 can be similar in structure and / or function to other energy delivery elements and / or guidewires described herein. The insulating collar 3524c can have a length between about 1 mm and about 20 mm, including all values ​​and subranges therebetween. As described above with respect to Figure 28A As described above, it may be desirable for the insulating collar of the guidewire to be flush (or substantially flush) with the outer surface of the guidewire. This can ensure that the surface of the guidewire does not have any edges or features that could cause it to accidentally get caught or engage with other structures. In some embodiments, to provide a flush outer surface for the guidewire, the collar can be deployed over a section of the guidewire where the core wire (or other internal component) gradually decreases in thickness. For example, Figure 34 As depicted in , the loop 3524b can be deployed on the area of ​​the guidewire where the core wire 3524c has a smaller diameter. Optionally, this area can also have a coil 3524d deployed on the core wire, which can also be compressible to further allow the loop to be flush with the outer surface of the guidewire. Similar to other guidewires described herein, the guidewire can also include a tip 3524a.

[0163] In some embodiments, the guidewires described herein include a thermally conductive portion. As described above, the use of an RF-powered guidewire or needle to create an atrial septal defect (e.g., for transseptal access) can pose a risk of thromboembolism due to the unintended formation of scorches and / or clots. Scorches and clots can occur when tissue temperature rises above a threshold that causes protein denaturation, dehydration, and / or a thrombotic cascade. Therefore, maintaining the guidewire tip temperature below a predefined threshold can prevent or reduce the risk of scorch and clot formation, thereby sparing the patient from thromboembolic risk.

[0164] Figure 35A schematic diagram illustrating temperature control using the energy delivery elements and guidewires described herein, according to an embodiment, is depicted. As depicted, a generator 3610 (e.g., similar in structure and / or function to other generators described herein) is coupled to an energy delivery device 3622. A physician can actuate an actuator device (e.g., similar in structure and / or function to other actuators or actuator devices described herein) to cause RF output to be delivered to the energy delivery element 3622. The energy delivery element 3622 can be similar in structure and / or function to other energy delivery elements and / or guidewires described herein. In embodiments, the energy delivery element 3622 can be a guidewire. One or more temperature sensors (e.g., thermistors, thermocouples, etc.) can be coupled to or embedded in the energy delivery device near the intended tissue contact area, for example, to monitor the temperature at the tissue contact area. The temperature sensor signal(s) can then be sent to the generator 3610, which can be configured to modulate or control the RF output based on temperature feedback. In some embodiments, the generator 3610 can be configured to deliver RF output to achieve a target set point temperature or range. The target set point temperature or range can be between about 55 and about 80 degrees Celsius, including all values ​​and subranges therebetween. By avoiding temperatures above 80 degrees Celsius, the incidence of scorching and clot formation can be reduced.

[0165] In some embodiments, the guidewire may include a thermally conductive material that can be configured to wick or pull heat away from the tip of the guidewire. Existing guidewires may include irrigated guidewires that directly cool the electrode and nearby tissue. However, in some cases, clots may still form on the electrode of an irrigated guidewire, particularly near the boundary between the electrode and the proximal polymer insulation layer of the tip, for example, due to poor heat conduction of the polymer, where heat from the tip may be trapped. Currently, existing guidewires for transseptal access do not include irrigated. Energy delivery devices or guidewires as described herein can provide cooling via larger tip electrodes. This is because non-insulated, longer active electrode areas (e.g., greater than approximately 1 cm, 2 cm, etc.) can wick or pull heat away from the tip of the guidewire, while other guidewires may include plastic or insulating materials that prevent heat transfer. However, as described above, it may be desirable to cover a portion of the active electrode with an electrically insulating material, thereby maintaining the RF current density under various conditions of use (e.g., if the expander-tissue contact is not perpendicular). In such embodiments, an insulating collar may be used to cover a portion of the active electrode or the conductive outer surface of the guidewire, for example, as described in reference to Figure 29-34 and Figure 40-42C The collar may be formed of a thermally conductive material such that the collar does not prevent or reduce heat transfer away from the tip and does not increase the risk of burning or clotting.

[0166] Figure 40The tip of a guidewire 4224 including a thermally conductive portion according to an embodiment is depicted. The guidewire 4224 can be structurally and / or functionally similar to other guidewires described herein, including, for example, Figure 1 For example, the guidewire 4224 may include a tip 4224a, a thermally conductive portion 4224b, an electrically conductive portion 4224d, and a standard insulating portion 4224e.

[0167] Tip 4224a is formed of a solid metal (e.g., stainless steel, etc.) configured to deliver energy for piercing the septum. Tip 4224a can have a length between approximately 0.1 mm and approximately 1 mm, including all values ​​and subranges therebetween, including, for example, approximately 0.5 mm. In some embodiments, the tip can be a conductive portion having a length between approximately 0.25 mm and 30 cm. Thermally conductive portion 4224b can be adjacent to and proximal to tip 4224a. In some embodiments, thermally conductive portion 4224b can be implemented as an electrically insulating collar, similar to other insulating collars described herein (e.g., collar / PET coating in device 3, collar 3524b). The location of thermally conductive but electrically insulating portion 4224b can allow current density to be concentrated at tip 4224a. Thermally conductive portion 4224b can be formed of a thermally conductive polymer or metal (e.g., tungsten, tantalum, platinum, gold, etc.). In some embodiments, thermally conductive portion 4224b can be configured to provide heat transfer and electrical insulation, thereby avoiding increasing the outer conductive surface area of ​​the guidewire. Therefore, materials such as platinum and gold that increase the conductive surface area of ​​the electrode may be less desirable.In some embodiments, the length of the thermally conductive portion 4224b (eg, or electrically insulating region) can be between about 2 mm and about 2 cm.

[0168] In some embodiments, the guidewire 4224 may optionally include a marker band 4224c. In such embodiments, the marker band 4224c may be adjacent to and proximal to the tip 4224a. The marker band 4224c may be implemented as a coating on the thermally conductive portion 4224b. Alternatively, the marker band 4224c may be an element or component separate from the thermally conductive portion 4224b. The marker band 4224c is formed from a material that allows the marker band 4224c to be visible during imaging, for example, a radiopaque material that is visible under fluoroscopy. The marker band 4224c may be made of a thermally conductive material, for example, to allow heat to be transferred from the tip 4224a. In some embodiments, the marker band 4224c may be implemented with a diamond coating that allows heat to dissipate while acting as an electrical insulator. The diamond coating may be deployed on a band made of a radiopaque material, such as platinum, tantalum, or tungsten.

[0169] The conductive portion 4224d is adjacent to the thermally conductive portion 4224b. The conductive portion 4224d may have a conductive outer surface. In some embodiments, the conductive portion 4224d may include one or more features (e.g., cutouts, holes, slits) that allow the conductive portion 4224d to have a conductive outer surface. For example, the conductive portion 4224d may include a reference Figure 11A and 11B Alternatively, or in addition, the conductive portion 4224d may include a conductive polymer coating. The conductive portion 4224d allows the current to be distributed along a portion of the length of the guidewire 4224, for example, by providing a larger active electrode area. The standard portion 4224e is a portion formed of an electrically insulating material (e.g., a polymer) configured to insulate and protect the guidewire 4224. In some embodiments, the length of the conductive portion 4224d is between about 5 mm and about 30 cm.

[0170] The construction of the guidewire 4224 allows the guidewire 4224 to operate at lower power than known systems because the marker band 4224a and the thermally conductive portion 4224b allow the current density to be concentrated at the tip 4224a during operation, while the conductive portion 4224d allows the current density to dissipate along the length of the guidewire 4224 after the tip 4224a engages and pierces the septum and the conductive portion 4224d is exposed. In some embodiments, the operating power is between about 10 watts and about 40 watts, including all subranges and values ​​therebetween. In some embodiments, the operating power is between about 10 watts and about 25 watts.

[0171] Figure 41 Depicted is a cross-sectional view of a guidewire 4224 according to an embodiment. Figure 41 As seen in the figure, the interior of the guide wire 4224 includes a core 4224f, an inner coil 4224g surrounding the core 4224f, and an outer coil 4224h surrounding the inner coil 4224g. The core 4224f is continuous with (e.g., coupled to) the tip 4224a. The inner coil 4224g is wrapped around the core and terminates at the tip 4224a. The outer coil extends along the guide wire 4224 to the marking band 4224b. The inner and outer coils can provide support while allowing flexibility of the guide wire. In some embodiments, the outer coil 4224h is coated. In some embodiments, the coating is a polymer. In some embodiments, the coating is gold, for example, for heat transfer. In some embodiments, the diameter or size of the wire used to form the outer coil 4224h is larger than the diameter or size of the wire used to form the inner coil 4224g.

[0172] Figures 42A-42CAnother example of a guidewire 4424 according to an embodiment is depicted. The guidewire 4424 can be similar in structure and / or function to other energy delivery elements or guidewires described herein (including, for example, energy delivery element 124, guidewires 624, 724, 924, 4224, etc.). Thus, the guidewire 4424 can include components similar to those of other guidewires described herein. For example, the guidewire 4424 can include a tip 4424a, a loop 4424b, and a conductive portion 4424d. The guidewire 4424 is configured to be deployed within an expander or sheath 4426, which can be similar in function and / or structure to other expanders and / or sheaths described herein (e.g., sheaths 126, 426, 626, 726, etc.).

[0173] Figure 42A The guidewire is depicted extending a short distance from the outer sheath or dilator 4426. For example, the guidewire can extend a distance between about 0.5 mm and about 15 mm, including all values ​​and subranges therebetween. As described above, for example, with reference to Figure 8B , the guide wire can extend a short distance from the expander 4426 to expose the conductive tip 4424a of the guide wire. The conductive tip 4424a can then be used to deliver energy to perforate through the tissue. When the guide wire extends these short distances from the expander 4426, the guide wire has a small conductive surface area exposed. This small conductive surface area can allow current density to be concentrated at the tip 4424a of the guide wire, thereby enabling the tip to generate enough energy to perforate through a tissue wall, such as, for example, a septum. As described above, in some embodiments, the guide wire can have a loop 4424b, which can be formed of an insulating material or a low conductivity material. The loop 4424b can be deployed adjacent to the tip 4424a of the guide wire so that when the guide wire extends these short distances from the expander 4426, the conductive surface area of ​​the guide wire exposed outside the expander 4426 does not increase or remains the same (or substantially the same). This can ensure that the current density at the tip of the guidewire remains high enough to perforate through a certain thickness of tissue (e.g., between about 0.1 mm and about 15 mm). As described above, in some embodiments, the collar 4424b can also be formed of a thermally conductive material (such as, for example, gold). This can allow heat to be drawn away from the tip of the guidewire, for example, to avoid undesirable effects as described above.

[0174] like Figure 42B As shown in , the guidewire can extend a greater distance beyond the distal end of the dilator 4426. Figure 8CAs described above, after the guidewire pierces or perforates through the target tissue (e.g., the septal wall), the guidewire can be extended beyond the tissue. In some embodiments, the guidewire can be used as a delivery conduit for additional instruments. For example, the guidewire can be used to perform a transseptal crossing and then used to guide additional instruments (e.g., electrosurgical or therapeutic equipment, catheters, etc.) into the left atrium of the heart. When the guidewire is extended this longer distance, such as Figure 42B As shown in , the guidewire can be configured to assume an anti-injury shape, such as, for example, a J-shape, a pigtail shape, etc. The anti-injury shape can be configured to reduce damage to nearby tissue structures. When the guidewire is extended this greater distance, the distal conductive surface or conductive portion 4424b of the guidewire is also exposed. This distal conductive portion 4424b can be an exposed surface of a metal coil or other conductive material. The coil can be electrically coupled to the core wire 4424c of the guidewire, such as Figure 42C . Thus, the energy delivered to the tip can be spread across the tip and the additional exposed conductive surface 4424d. As described above, this larger conductive surface area reduces the current density and thereby further prevents and / or reduces the formation of possible lesions in nearby tissue structures. For example, when used in a transseptal crossing procedure, the larger exposed conductive surface area of ​​the guidewire can reduce the likelihood of damaging the heart wall, as described above.

[0175] Although Figures 42B-42C The additional conductive surface 4424d is shown as an exposed surface of the coil, but it will be appreciated that other conductive surfaces may be used to increase the total conductive surface area of ​​the guidewire. Figures 11A-11B and Figures 40-41 As depicted, conductive surface 4424d may also be formed from an insulating coating including cutouts or patterns formed therein that expose underlying conductive elements.

[0176] Figure 42C A detailed cross-sectional view of the guidewire 4424 is provided. Figure 42C , the core 4424c of the guide wire extends over the entire length of the guide wire. In some embodiments, the core 4424c can have a proximal portion whose diameter is greater than that of the distal section. At the proximal end of the guide wire or near it, the core 4424c can be exposed so that the core 4424c can be placed in electrical communication with the generator (e.g., via any electrosurgical interface described herein, e.g., electrosurgical interface 122, 222, 322, 422, 522, 622, etc.). Alternatively, in some embodiments, the core 4424c can be covered by an insulating material, but include one or more openings (e.g., holes, slits or other incisions) that enable electric current to be passed to the core 4424c, such as those described above with reference to Figures 11A-11BThe core 4424c may then be covered with an insulating coating or layer 4424e (such as, for example, a polymer). The insulating layer 4424e may cover the core 4424c up to the distal segment of the guidewire. The length of this distal segment may be between about 10 and about 100 cm, including all values ​​and subranges therebetween.

[0177] Starting at or near the beginning of the distal segment of the guidewire, the guidewire can transition from being covered by the insulating layer 4424e to having a conductive coil 4424d on the outside. As described above, the conductive coil 4424d can be formed from a conductive material (such as a metal or metal alloy). The coil 4424d can then extend distally from the distal end of the insulating layer 4424e to the tip 4424a of the guidewire. As described above, the coil 4424d can be coupled to the distal tip 4424a so that the coil 4424d can form a long electrode or conductor with the tip 4424a. When the coil 4424d is exposed along with the tip 4424a, for example, beyond the distal end of the dilator, the coil 4424d and the tip 4424a can provide a larger surface area over which the energy or current delivered to the guidewire can be spread,

[0178] For example, to reduce the current density at the tip 4424a. Figure 42C 4424b can be disposed near the tip 4424a of guide wire or adjacent thereto. In certain embodiments, the collar 4424b can be disposed on the coil 4424d. In such embodiments, the coil 4424d can have an outer diameter smaller than that in other regions so that the outer diameter of the guide wire in the region of the collar 4424b does not change. In other embodiments, the guide wire 4424b can have a slightly larger diameter in the region of the collar 4424b.

[0179] method

[0180] Figure 12 is a flow chart of a method 1200 of using the systems and devices described herein, according to an embodiment. The method 1200 includes: at 1202, attaching a guidewire (e.g., functionally and / or structurally coupled to a Figure 1at 1206, positioning the distal end of the guidewire against tissue (e.g., a septum); at 1208, activating energy delivery to perforate the tissue; at 1210, advancing the guidewire through the perforation; at 1212, advancing a dilator over the guidewire to dilate the perforation; and, at 1214, optionally advancing a medical device (e.g., a catheter) over the guidewire to the target site for treatment.

[0181] At 1202, a guidewire is navigated to a target location in the patient's body. The target location can be the right atrium of the heart or other patient anatomical structures (e.g., in the heart, vascular system, or other anatomical structures). In some embodiments, the guidewire is inserted into the femoral vein via a puncture hole formed by a standard needle puncture technique. The guidewire is navigated or advanced through the vascular system using fluoroscopy and / or ultrasound imaging. The guidewire can be navigated through the vascular system and positioned above the right atrium of the superior vena cava (SVC).

[0182] Before or after the guide wire is navigated to the right atrium (or other anatomical structure), the guide wire can be connected to a generator, for example, via an electrosurgical interface (e.g., electrosurgical interface 122, 222, etc.). In order to connect the guide wire to receive energy from the generator, an intervascular sheath and / or dilator (e.g., sheath 126, dilator 426, etc.) can be prepared by attaching the electrosurgical interface to the lumen of the sheath via a standard Luer connection. In some embodiments, the fluid lumen is flushed with a sterile 0.9% sodium chloride saline solution to remove the air in the lumen. The sheath is then loaded onto the proximal end of the guide wire and advanced into the patient's vascular system so that the distal tip of the dilator is located in the right atrium.

[0183] In some embodiments, as described above, the guide wire can have a J-shaped or other anti-damage distal shape. In such embodiments, it may be necessary to place the guide wire into a specific structure first, and then the guide wire can be used to perforate the tissue. Therefore, at 1204, the guide wire is optionally placed into a structure for perforation (for example, a straight or substantially straight structure). In some embodiments, placing the guide wire into a structure for perforation includes advancing the sheath on the distal curved portion of the guide wire as described above to straighten the guide wire. In some embodiments, placing the guide wire into a structure for perforation includes retracting the guide wire into the sheath so that the guide wire is straightened. When positioned for perforation, the guide wire tip can be exposed from the distal end of the dilator by about 1 to about 2 mm. Alternatively, in some embodiments, the guide wire may not have a J-shaped structure. In such embodiments, it may be possible to straighten or place the guide wire into a structure for perforation without moving the guide wire relative to the sheath. Therefore, 1204 can be omitted.

[0184] At 1206, the distal end (e.g., tip) of the guidewire is positioned against tissue. In some embodiments, the tissue is a portion of the atrial septum of the heart. In some embodiments, the sheath can be a steerable sheath and / or dilator and thus can be used to position or direct the guidewire toward the tissue, for example, by actuating a steering mechanism (e.g., a pull wire) on the sheath to deflect the distal portion of the sheath. In some embodiments, a pull-down technique is performed wherein the distal end of the dilator is directed toward the fossa ovalis (FO) and facilitates tenting (e.g., as shown in FIG. 1206 ) the tissue (e.g., the septum) via fluoroscopic and / or ultrasound imaging. Figure 8B In some embodiments, the operator may desire to reposition the dilator after performing tenting. To reposition, the guidewire may be re-advanced into the SVC and the pull-down technique may be repeated.

[0185] At 1208, energy delivery is activated to perforate the tissue. The perforation is formed by the tip of the guide wire delivering energy to the tissue and forming the perforation. In some embodiments, electrosurgical energy is applied by actuating a button or other actuator (e.g., button 422b) connected to the electrosurgical interface. In some embodiments, the perforation is formed by applying energy and applying slight pressure to the tissue with the guide wire. Once the puncture hole is formed in the tissue, energy delivery is stopped. In some embodiments, the formation of the puncture hole can be confirmed via imaging and / or tactile sensation.

[0186] At 1210, the guidewire is advanced through the perforation formed in 1208. In some embodiments, the guidewire transitions back to its curved configuration (e.g., as Figure 8C In some embodiments, a guidewire is advanced through the FO and positioned in the left atrium or pulmonary vein. At 1212, a sheath with a dilator can be advanced over the guidewire to dilate the perforation. In some embodiments, the dilator is advanced through the FO and positioned in the left atrium.

[0187] In some embodiments, at 1214, the dilator and electrosurgical interface can be retracted and removed, and additional equipment (eg, a catheter and / or sheath) can be advanced over the guidewire and into the left atrium (or other target anatomy).

[0188] In some embodiments, an outer sheath can be positioned around the dilator and / or guidewire and advanced into the left atrium, for example, simultaneously with or shortly after the dilator. This outer sheath can be positioned over the dilator and / or guidewire after the perforation has been formed and expanded and the electrosurgical interface has been removed from the proximal end of the dilator. Alternatively, this outer sheath can be positioned over the dilator at the beginning of the procedure and used with the dilator at 1204, 1206, and 1212. In such embodiments, the outer sheath can be used to provide a pathway or passageway into the left atrium. The dilator and guidewire are removed from the outer sheath, while the sheath lumen remains in the left atrium. At 1214, a medical device (e.g., a catheter, etc.) is advanced through the sheath lumen and reaches the target site for treatment.

[0189] In some embodiments, a therapeutic ablation catheter is advanced into the left atrium so that pulmonary vein isolation can be performed.Once the procedure is performed, the medical device is removed.

[0190] Overall reference Figure 13 and Figure 14 , changes from the generator (e.g., functionally and / or structurally similar to Figure 1 110) delivered to a guidewire (e.g., functionally and / or structurally similar to a generator 110 of Figure 1 In some embodiments, it may be desirable to vary the energy delivered to the guidewire tip based on a measured characteristic, such as, for example, temperature. This can help avoid a buildup of heat at the distal tip of the guidewire, thereby preventing undesirable microbubble formation. In some embodiments, it may be desirable for the guidewire to deliver varying amounts of energy to the tissue. For example, when the distal tip of the guidewire is in line with or slightly beyond the tip of the sheath (e.g., approximately 1 mm), the guidewire has a small effective surface area, which can result in a high potential current density and, therefore, heating near the guidewire tip. As the guidewire extends out of the sheath, the exposed surface area of ​​the guidewire increases, thereby reducing the current density. In order to control potential changes in current density, it may be beneficial to vary the energy delivered to the guidewire to prevent the guidewire from causing unintended damage to the tissue.

[0191] Figure 13 A flow chart of a method 1300 for changing the RF output delivered to a guidewire according to an embodiment is depicted. The method 1300 includes modifying the output based on at least one characteristic associated with the guidewire. In some embodiments, the guidewire can include at least one sensor to measure the at least one characteristic (e.g., the state of the guidewire, the temperature). In some embodiments, the sensor can be configured to capture data indicative of the at least one characteristic and send the data to a generator that can adjust the energy delivered to the guidewire in response to receiving the data.

[0192] At 1302, method 1300 includes delivering an RF output to a guidewire via an RF generator. In some embodiments, the amount of RF output delivered to the guidewire can be predetermined. In some embodiments, the amount of RF output delivered to the guidewire can be determined based on predetermined parameters (e.g., patient parameters, device parameters, etc.). At 1304, method 1300 includes detecting at least one characteristic associated with the guidewire. In some embodiments, the at least one characteristic can be RF current, RF output, temperature, current density, pressure, current, voltage, etc. In some embodiments, the at least one characteristic can be the state of the guidewire. For example, the state can include being located within a sheath, starting to advance from the sheath, engaging with tissue, etc. As another example, the at least one characteristic can include current density at / around the tip of the guidewire.

[0193] At 1306, method 1300 includes modifying the RF output based on at least one characteristic. Modifying the RF output may include modifying output power, peak-to-peak voltage, duty cycle, etc. For example, if the temperature at the guidewire tip is determined to be greater than a predetermined threshold, the RF output may be modified to deliver less power to the guidewire. As another example, if a pressure sensor detects a puncture in the heart's septum, the RF output may be reduced to reduce the likelihood of accidental damage. As another example, the RF output may be modified based on the current density at / around the guidewire tip and based on the position of the guidewire tip. For example, if the guidewire tip is in contact with the heart wall and the current density is greater than a desired value (e.g., such that it may cause damage), the RF output may be reduced. After modifying the RF output, method 1300 includes delivering the modified RF output to the guidewire at 1308. After delivering the RF output to the guidewire, method 1300 may return to 1304 to again detect at least one characteristic associated with the guidewire. Repeating steps 1304-1308 allows the system to dynamically change to reduce the likelihood of tissue damage based on the at least one detected characteristic.

[0194] Figure 14A flow chart depicts a method 1400 for delivering RF output to a guidewire according to an embodiment. Method 1400 includes modifying the output to the guidewire based on an output schedule. This allows for the delivery of predetermined amounts of energy during different phases of a procedure. In some embodiments, the output schedule is predetermined. In some embodiments, the treatment schedule can be modified based on the patient, device, etc. In some embodiments, the treatment schedule can be user-defined. At 1402, method 1400 includes delivering RF output to the guidewire via an RF generator at a first power parameter for a first time period. At 1404, method 1400 includes delivering RF output to the guidewire via the RF generator at a second power parameter for a second time period. At 1406, method 1400 optionally includes delivering RF output to the guidewire via the RF generator at a third power parameter for a third time period. In some embodiments, method 1400 may include additional steps for delivering RF output to the guidewire at additional power parameters for additional time periods. The power parameter may correspond to a duty cycle. The time period may correspond to a duration associated with operation of the guidewire. For example, the first power parameter may include a 10% duty cycle, the second power parameter may include a 50% duty cycle, the first time period may be 25% of the treatment duration, and the second time period may be 75% of the treatment duration.

[0195] Additionally or alternatively, in some embodiments, a generator (e.g., as described herein, 110) can detect when the current density at the distal end of the guidewire decreases (e.g., due to an increase in the conductive area of ​​the surface caused by cutting tissue) and can be adapted to deliver more current until a predefined or user-programmed limit is reached. When the exposed surface area of ​​the wire is small, a smaller current may be required, but as the wire extends into the tissue, the increasing surface area may require more current to maintain a current density effective for perforating through the tissue. When the guidewire is fully deployed (e.g., 1 cm from the tip of the dilator or other insulated shaft), even with higher RF output, the current density is too low to cause unintended tissue damage.

[0196] It should be understood that the examples and descriptions in this disclosure are for illustrative purposes only and that various deviations and variations may be constructed and deployed in accordance with the teachings herein without departing from the scope of the invention. For example, while the systems disclosed herein are shown as having a monopolar configuration in which the circuit is completed by a remotely positioned return electrode placed outside the patient's body, in alternative embodiments, such systems may have a bipolar configuration in which the return electrode is placed inside the patient's body, such as, for example, a metal ring electrode deployed on a sheath, dilator, or catheter.

[0197] As used herein, when used in conjunction with numerical values ​​and / or ranges, the terms "about" and / or "approximately" generally refer to those numerical values ​​and / or ranges that are close to the numerical values ​​and / or ranges. In some cases, "about" and "approximately" mean within ±10% of the numerical value. For example, in some cases, "approximately 100 [units]" can mean within ±10% of 100 (e.g., 90 to 110). The terms "about" and "approximately" can be used interchangeably.

[0198] Some embodiments described herein relate to a computer storage product having a non-transitory computer-readable medium (also referred to as a non-transitory processor-readable medium) on which are stored instructions or computer code for performing various computer-implemented operations. A computer-readable medium (or processor-readable medium) is non-transitory because it does not itself include transient propagating signals (e.g., propagating electromagnetic waves that carry information over a transmission medium such as space or a cable). The medium and computer code (also referred to as code or algorithm) can be designed and constructed for one or more specific purposes. Examples of non-transitory computer-readable media include, but are not limited to: magnetic storage media such as hard disks, floppy disks, and magnetic tapes; optical storage media such as compact disks / digital video disks (CD / DVDs), compact disk read-only memories (CD-ROMs), and holographic devices; magneto-optical storage media such as optical disks; carrier signal processing modules; and hardware devices specifically configured to store and execute program code, such as application-specific integrated circuits (ASICs), programmable logic devices (PLDs), read-only memories (ROMs), and random access memory (RAM) devices. Other embodiments described herein relate to computer program products that may include, for example, the instructions and / or computer code disclosed herein.

[0199] The systems, devices, and / or methods described herein may be implemented by software (implemented on hardware), hardware, or a combination thereof. Hardware modules may include, for example, a general-purpose processor (or microprocessor or microcontroller), a field programmable gate array (FPGA), and / or an application-specific integrated circuit (ASIC). Software modules (implemented on hardware) may be expressed in a variety of software languages ​​(e.g., computer code), including C, C++, Ruby, Visual and / or other object-oriented, procedural or other programming languages ​​and development tools. Examples of computer code include, but are not limited to, microcode or microinstructions, machine instructions (such as those generated by a compiler), code for generating web services, and files containing higher-level instructions executed by a computer using an interpreter. Additional examples of computer code include, but are not limited to, control signals, encrypted code, and compressed code.

[0200] The specific examples and descriptions herein are exemplary in nature and one skilled in the art may develop embodiments based on the teachings herein without departing from the scope of the present invention, which is limited only by the appended claims.

Claims

1. A guide wire comprising: a conductive distal tip configured to deliver radiofrequency (RF) energy to a septum of a subject to form a perforation through the septum; a conductive core coupled to the distal tip, the conductive core configured to conduct RF energy to the distal tip; a conductive outer portion disposed proximate the distal tip, the conductive outer portion configured to couple to the distal tip via the conductive core; as well as an insulating collar disposed between the distal tip and the conductive outer portion, The guidewire is configured to extend distally from the insulating shaft a first distance to expose the distal tip to allow the distal tip to deliver RF energy and form a perforation, The guidewire is also configured to extend distally from the insulating shaft a second distance greater than the first distance to expose the distal tip and at least a portion of the conductive outer portion to increase the exposed surface area of ​​the conductive portion of the guidewire, thereby reducing current density along the conductive portion.

2. The guidewire of claim 1, wherein the conductive core and the distal tip are formed of the same material.

3. The guidewire of any one of claims 1-2, further comprising a non-conductive outer portion disposed proximal to the conductive outer portion, the non-conductive outer portion being configured to be grasped by a user to advance the guidewire distally. The guidewire of claim 3 , wherein the non-conductive outer portion comprises a polymer layer.

5. The guidewire of any one of claims 1-4, wherein the conductive outer portion comprises a gold plating configured to conduct heat away from the distal tip when the distal tip delivers RF energy.

6. The guidewire of any one of claims 1-5, wherein the conductive outer portion comprises a metal coil.

7. The guidewire of any one of claims 1-6, wherein the conductive outer portion comprises a conductive polymer.

8. The guidewire of any one of claims 1-7, wherein the conductive outer portion comprises one or more openings formed in an insulating coating disposed over the conductive core.

9. The guidewire of any one of claims 1-8, wherein the insulating collar is disposed over a portion of the metal coil.

10. The guidewire of claim 9, wherein the metal coil in the region having the insulating collar is compressed or elongated relative to other portions of the metal coil.

11. The guidewire of any one of claims 1-10, wherein the insulating loop has a length of between about 1 mm and about 20 mm.

12. The guidewire of any one of claims 1-11, wherein the first distance is less than about 10 mm.

13. The guidewire of any one of claims 1-12, wherein the insulating collar comprises a thermally conductive material configured to conduct heat away from the distal tip when the distal tip delivers RF energy.

14. An apparatus comprising: an insulative shaft comprising a proximal end and a distal end and defining a lumen therethrough; a guidewire configured to be slidably deployed within the lumen, the guidewire configured to be advanced distally relative to the insulating shaft to expose a distal tip of the guidewire, the distal tip of the guidewire being configured to deliver radiofrequency (RF) energy to a septum of the subject to form a perforation through the septum when exposed; an electrosurgical interface coupled to the proximal end of the insulating shaft and to the generator, the electrosurgical interface comprising a passageway aligned with the lumen of the insulating shaft such that a guidewire can extend through the passageway and the lumen of the insulating shaft, the electrosurgical interface configured to establish an electrical coupling between the generator and the guidewire and to maintain the electrical coupling as the guidewire is advanced distally of the distal end of the insulating shaft; as well as An actuator configured to, in response to being actuated when the distal tip is exposed, send a signal to the generator such that the generator generates a voltage output and delivers the voltage output to the guidewire via electrical coupling to cause the distal tip to deliver RF energy to form a perforation.

15. The apparatus of claim 14, wherein the passageway of the electrosurgical interface is configured to receive a conductive fluid, and the guidewire further comprises a conductive outer portion electrically coupled to the distal tip, The electrosurgical interface is configured to establish electrical coupling when the conductive outer portion is deployed in the conductive fluid.

16. The device of claim 15, wherein the guidewire further comprises a non-conductive portion disposed proximal to the conductive portion, the non-conductive portion being configured to be grasped by a user to advance the guidewire.

17. The apparatus of claim 15, wherein the electrosurgical interface comprises an electrode coupled to the generator and in contact with at least one of the conductive fluid or the conductive outer portion of the guidewire.

18. The device of claim 15, wherein the guidewire further comprises a core wire coupled to the distal tip, the conductive outer portion of the guidewire being electrically coupled to the distal tip via the core wire.

19. The device of claim 18, wherein the guidewire further comprises an insulating coating disposed over the core wire along at least a portion of the core wire, and the conductive outer portion of the guidewire comprises at least one opening formed in the insulating coating.

20. The device of claim 18, wherein the conductive outer portion of the guidewire comprises a conductive coating or coil disposed over a core wire.

21. The device of any one of claims 14-20, wherein the guidewire further comprises a conductive outer portion disposed near the distal tip, The conductive outer portion is electrically coupled to the distal tip, The guidewire is further configured to be advanced distally relative to the insulating shaft after the distal tip is perforated to expose the conductive outer portion to reduce current density of RF energy at the distal tip.

22. The device of claim 21, wherein the guidewire further comprises an insulating collar disposed between the distal tip and the conductive outer portion.

23. The apparatus of claim 22, wherein the insulating collar has a length of between about 1 mm and about 20 mm.

24. The device of any one of claims 14-23, wherein the insulating shaft is a dilator configured to be advanced distally after the distal tip forms the perforation to dilate the perforation so that a surgical instrument can be advanced along the guide wire and through the perforation to a target site.

25. The apparatus of any one of claims 14-24, wherein the electrosurgical interface further comprises a housing, The actuator is disposed on the housing and is configured to slide along the housing when actuated.

26. The device of any of claims 14-25, wherein the guidewire is configured to form an atraumatic shape when advanced distally relative to the insulating shaft.

27. A system comprising: generator; as well as Electrosurgical equipment, including: a guidewire configured to deliver radiofrequency (RF) energy to a septum of a subject and perforate the septum; and an electrosurgical interface configured to couple to a generator, the electrosurgical interface comprising a passageway configured to slidably receive a guidewire such that the guidewire and the electrosurgical interface are movable relative to each other, the electrosurgical interface configured to establish an electrical coupling between the guidewire and the generator and to maintain the electrical coupling as the guidewire moves relative to the electrosurgical interface; The generator is configured as: In response to receiving the activation signal, generating a voltage output and delivering the voltage output to the guidewire via the electrical coupling; and A characteristic associated with the electrosurgical device is monitored and the voltage output is modulated based on the characteristic.

28. The system of claim 27, wherein the guidewire further comprises one or more temperature sensors deployed at the distal tip of the guidewire, and The characteristic monitored by the generator is the temperature associated with the distal tip of the guidewire, The generator is configured to modulate the voltage output by modulating the voltage output to maintain a temperature associated with the distal tip at a predetermined set point temperature.

29. The system of claim 28, wherein the predetermined set point temperature is between approximately 55 degrees Celsius and approximately 80 degrees Celsius.

30. The system of any one of claims 27-29, further comprising a return electrode operably coupled to the generator and the electrosurgical device, and The characteristic monitored by the generator is the impedance of the circuit formed by the generator, the electrosurgical device, and the return electrode, The generator is configured to modulate the voltage output by: In response to determining that the impedance is greater than a predetermined threshold, the voltage output is reduced so that power associated with the circuit is less than or equal to a predetermined value.

31. The system of claim 30, wherein the predetermined value is between about 5W and about 100W.

32. The system of any of claims 27-31, wherein the electrosurgical device further comprises an insulative shaft defining a lumen, the guidewire being configured to be slidably received in the lumen.

33. The system of any of claims 27-32, wherein the passageway of the electrosurgical interface is configured to receive a conductive fluid, and the guidewire further comprises a conductive outer portion electrically coupled to the distal tip, The electrosurgical interface is configured to establish electrical coupling when the conductive outer portion is deployed in the conductive fluid.

34. The system of claim 33, wherein the electrosurgical interface comprises an electrode coupled to the generator and in contact with at least one of the conductive fluid or the conductive outer portion of the guidewire.

35. The system of any of Claims 27-34, wherein the electrosurgical device further comprises an actuator configured to generate an activation signal in response to being actuated.

36. The system of any of claims 27-35, wherein the guidewire further comprises an insulating collar disposed proximate the distal tip of the guidewire, the insulating collar having a length between approximately 1 mm and approximately 20 mm.

37. A method comprising: extending a guidewire deployed within the insulating sheath a first distance distal to a distal end of the insulating sheath, with the guidewire and insulating sheath deployed proximate to a tissue wall; deploying the distal tip of the guidewire against the tissue wall; After deploying the distal tip of the guidewire against the tissue wall, delivering radiofrequency (RF) energy to the tissue wall via the distal tip; The guidewire is also extended distally while delivering RF energy to form a perforation through the tissue wall; In response to extending the guidewire a second distance distal to the distal end of the insulating sheath, at least a portion of the conductive outer portion of the guidewire is exposed, thereby increasing the exposed conductive surface area of ​​the guidewire after the perforation is formed.

38. The method of claim 37, wherein increasing the exposed conductive surface area of ​​the guidewire reduces the current density at the distal tip of the guidewire.

39. The method of any of claims 37-38, wherein the tissue wall is a septum, and the septum is tented using the distal tip of the guidewire prior to delivering RF energy to the septum.

40. The method of any of claims 37-39, wherein the insulating sheath is a dilator, and further comprising: A dilator is advanced over the guidewire and through the perforation to dilate the perforation.

41. The method of any one of claims 37-40, further comprising: After forming the perforation, retracting the insulating sheath; as well as The surgical instrument is advanced over the guidewire and through the perforation to navigate the surgical instrument to the target site.

42. The method of claim 41 , further comprising: After the surgical instrument is navigated to the target site, a surgical procedure is performed using the surgical instrument.

43. An energy delivery element for perforating biological tissue, the energy delivery element comprising: A lead comprising a distal tip comprising a first conductive region, a first insulating region disposed proximate the conductive tip, and a second conductive region disposed proximate the first insulating region, wherein When the energy delivery device is energized by a generator (of a certain standard configuration) and at least partially enclosed in an insulating tube, the energy delivery device exhibits a current density that is a function of displacement relative to the distal end of the insulating tube, wherein When the distal tip including the first conductive region extends less than 10 mm beyond the end of the insulating tube, wherein the current density is greater than 45 A / cm 2 And less than 250A / cm 2 ; When the distal conductive tip extends 10 mm beyond the end of the insulating tube, the current density associated with the first conductive region is less than 60 A / cm2 and the current density associated with the second conductive region is less than 60 A / cm2. 2 ; as well as When the distal conductive tip extends 20 mm beyond the end of the insulating tube, the current density distributed from the first conductive region is in the range of less than 25 A / cm2 and the current density distributed from the second conductive region is less than 25 A / cm2. 2 .

44. The energy delivery element of claim 43, wherein The length of the distal conductive tip is between 0.25 mm and 30 cm; The length of the first insulating region is between 2 mm and 2 cm; and The length of the proximal conductive area is between 5 mm and 30 mm.

45. The energy delivery element of claim 44, wherein the distal conductive tip is uncoated.

46. ​​The energy delivery element of claim 44, wherein the first insulating region is coated with a dielectric material.

47. The energy delivery element of claim 44, wherein the proximal conductive region is uncoated, partially coated, or coated with a conductive polymer.

48. The energy delivery element of any of claims 43-47, further comprising a second insulating region disposed proximal to the proximal conductive region.

49. A method of penetrating biological tissue comprising providing an energy delivery element as claimed in any one of claims 43 to 48, the method comprising: deploying an energy delivery element within the expander; Advance the distal tip beyond the dilator; energizing the energy delivery element; as well as Monitor impedance.

50. An electrosurgical interface, comprising: a housing defining a lumen and including a conductive element, the conductive element and lumen being sized to slidably receive an energy delivery element; an energized wire connected to the conductive element; as well as an actuator for modulating energy delivered by the energized wire; When the actuator is in an energized state, radio frequency (RF) energy is transferred to the energy delivery element via the conductive element.

51. An electrosurgical interface as described in claim 50, wherein RF energy is delivered to the energy delivery element via the conductive element via at least one opening in the insulating coating of the energy delivery element.

52. An electrosurgical interface as described in Claim 51, wherein the at least one opening comprises a plurality of holes.

53. An electrosurgical interface as described in Claim 51, wherein the at least one opening comprises a slot.

54. An electrosurgical interface as described in Claim 51, wherein the at least one opening comprises a helical slot.

55. An electrosurgical interface as described in Claim 51, wherein the at least one opening comprises a plurality of slots.

56. An electrosurgical interface as described in Claim 50, wherein RF energy is delivered to the energy delivery element via a conductive polymer coating of the energy delivery element.

57. An electrosurgical interface as described in Claim 50, wherein RF energy is delivered to the energy delivery element via the conductive element via the holes in the conductive coating of the energy delivery element.

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