Configurable Plasma Generation System

Abstract

A power circuit for nonthermal plasma generation (optionally therapeutic plasma). Nonthermal plasma is generated distally by a catheter-like device that is flexible, narrow (e.g., <5 mm diameter), and extends longitudinally, e.g., 50-100 cm into a body cavity. The plasma probe power transmission cable is part of the power generation circuit, and its inherent impedance contributes to and constrains the time constant of a synchronous RC circuit whose resonant frequency synchronizes the power generation frequency via feedback. Variable length, structure, and / or fabrication (for example) of the plasma probe may result in different time constants. In some embodiments, the transformer coupling is split into multiple stages, and the final stage transformer inductance can be selected with sufficient margin to maintain the target operating frequency using compensation components to compensate for individual variations in the probe. Various configurations for selecting and / or providing the compensation components are disclosed.

Description

[Technical Field]

[0001] Related Applications This application is a continuation of U.S. Patent Application No. 18 / 129,116, filed March 31, 2023, which is a continuation of U.S. Patent Application No. 17 / 971,737, filed October 24, 2022, and issued April 4, 2023, as U.S. Patent No. 11,621,587, which is a continuation-in-part (CIP) of U.S. Patent Application No. 17 / 866,700, filed July 18, 2022, and issued April 11, 2023, as U.S. Patent No. 11,627,652.

[0002] This application is also a continuation-in-part of U.S. Patent Application No. 18 / 130,163, filed April 3, 2023, which is a continuation-in-part (CIP) of U.S. Patent Application No. 17 / 866,700, filed July 18, 2022, and issued April 11, 2023, as U.S. Patent No. 11,627,652.

[0003] This application is also related to a concurrently filed international patent application entitled "PLASMA GENERATING SYSTEM" (Applicant's Attorney Internal Docket No. 95980).

[0004] The contents of each of the above applications cited in this application are hereby incorporated by reference in their entirety. [Background technology]

[0005] Some embodiments of the present invention relate to the field of plasma generation, and more particularly to the design of plasma power sources.

[0006] Non-thermal atmospheric plasma (NTAP), also known as cold atmospheric plasma (CAP), is an ionized gas at near-room temperature composed of a variety of neutral and charged species. Its beneficial properties in medicine are well established, and it is widely used in various application fields and industries. The application of NTAP to tissues has complex and unique effects at both the cellular / tissue and systemic levels.

[0007] NTAP can be generated by dielectric barrier discharge (DBD), in which a flowing gas (typically a noble gas such as helium or argon) is ionized by an electrode to which a high voltage is periodically applied. The electrode is covered by a dielectric barrier, preventing a direct ohmic path between the driving source and the target tissue. Summary of the Invention

[0008] According to an aspect of some embodiments of the present disclosure, there is provided a power supply circuit for a non-thermal plasma generator, the power supply circuit comprising: a driver circuit configurable to generate an AC power signal at an operating frequency of at least 500 kHz; an output stage circuit connected to receive the AC power signal from the driver circuit and provide a feedback signal to the driver circuit for synchronizing the driver circuit to generate the AC power signal at the operating frequency, the output stage circuit having a plurality of transformers including at least a final transformer and an initial gain transformer; and a plasma generating element having a distal end having a plasma generation site and a proximal end coupled to the driver circuit via the output stage circuit, the distal end and the proximal end being coupled to the driver circuit via the output stage circuit, the plasma generating element comprising: a power supply circuit for generating an AC power signal at an operating frequency of at least 500 kHz; a plasma probe and a terminal interconnected by a transmission line having an intrinsic capacitance proportional to the length of the transmission line; and at least one compensation capacitor selectable and / or adjustable from a plurality of capacitances, wherein the selected and / or adjusted compensation capacitor from the at least one compensation capacitor is positioned electrically in parallel with the intrinsic capacitance of the transmission line and has a capacitance that compensates an LC network including the intrinsic capacitance and a secondary coil of the final transformer to resonate at the operating frequency when the driver circuit is executed to generate the AC power signal.

[0009] According to some embodiments of the present disclosure, the final transformer comprises a secondary coil and a primary coil, and the secondary coil of the final transformer is electrically connected to the plasma probe, the initial gain transformer comprises a secondary coil and a primary coil, and the secondary coil of the initial gain transformer is electrically connected to the plasma probe via the final transformer, and the primary coil of the initial gain transformer is electrically connected to the driver circuit.

[0010] According to some embodiments of the present disclosure, the inductance of the secondary coil of the final transformer is selected so that the LC network resonates at the operating frequency when a longest supported plasma probe having a longest supported transmission line length is connected without the selected and / or adjusted compensation capacitor, the plasma probe has a transmission line length shorter than the longest supported transmission line length, and the sum of the capacitance of the selected and / or adjusted compensation capacitor and the intrinsic capacitance of the short transmission line is matched to the intrinsic capacitance of the longest supported transmission line.

[0011] According to some embodiments of the present disclosure, the selected and / or adjusted compensation capacitor is provided as a component of the plasma probe and is selected by selection of the plasma probe.

[0012] According to some embodiments of the present disclosure, a proximal connector of the plasma probe comprises the at least one compensation capacitor.

[0013] According to some embodiments of the present disclosure, the at least one compensation capacitor is provided together with the driver circuit, and the plasma probe is electrically connected to the at least one compensation capacitor when attached to the driver circuit via the output stage circuit.

[0014] According to some embodiments of the present disclosure, the at least one compensation capacitor includes a plurality of compensation capacitors, and the power supply circuit includes a controller that selects the selected and / or adjusted compensation capacitor from the plurality of compensation capacitors and connects it to the plasma probe.

[0015] According to some embodiments of the present disclosure, the controller comprises a manually operated switch.

[0016] According to some embodiments of the present disclosure, the controller comprises an electrically operated switch.

[0017] According to some embodiments of the present disclosure, the electrically operated switch is one of a plurality of multiplexed switches.

[0018] According to some embodiments of the present disclosure, the controller selects and / or adjusts the selected and / or adjusted compensation capacitor in response to a user input command from a graphical user interface.

[0019] According to some embodiments of the present disclosure, the plasma probe may further include an identifier detector, wherein the controller selects and / or adjusts the selected and / or adjusted compensation capacitor in response to an identifier element associated with the plasma probe that provides an identifier sensed by the identifier detector and a compensation capacitance associated with the identifier.

[0020] According to some embodiments of the present disclosure, the identifier includes a resistance value measured when the plasma probe is electrically connected to the driver circuit.

[0021] According to some embodiments of the present disclosure, the identifier comprises a numeric value.

[0022] According to some embodiments of the present disclosure, the device further comprises a frequency detector, wherein the controller selects the compensation capacitor based on an identified actual frequency of operation of the device and a difference between that frequency and the operating frequency of at least 500 kHz.

[0023] According to an aspect of some embodiments of the present disclosure, there is provided a method for generating plasma, including providing a power supply configured to drive a high-capacitance plasma probe in cooperation with a secondary coil of a coupling transformer at a first frequency, wherein a capacitance of the high-capacitance plasma probe includes an intrinsic capacitance of a transmission line of the high-capacitance plasma probe; providing a low-capacitance plasma probe having a transmission line with a lower intrinsic capacitance than the intrinsic capacitance of the transmission line of the high-capacitance plasma probe; selecting a compensation capacitor based on a difference in capacitance between the high-capacitance plasma probe and the low-capacitance plasma probe; electrically connecting the compensation capacitor in parallel with the intrinsic capacitance of the low-capacitance plasma probe; and operating the low-capacitance plasma probe at the first frequency.

[0024] According to some embodiments of the present disclosure, an RC network including the secondary coil and the transmission line of the low capacitance plasma probe, without the compensation capacitor, resonates at a second frequency higher than the first frequency.

[0025] According to some embodiments of the present disclosure, an RC compensation capacitor has a capacitance approximately equal to the difference in capacitance between the high-capacitance plasma probe and the low-capacitance plasma probe.

[0026] According to some embodiments of the present disclosure, the selecting includes selecting the compensation capacitor from a plurality of capacitors and / or adjusting a capacitance of the compensation capacitor.

[0027] According to one aspect of some embodiments of the present disclosure, a set of at least two plasma probes, each comprising a distally located plasma generation site, a proximally located connector configured to connect to a plasma power source, and a transmission line interconnecting the connector and the plasma generation site, wherein the plasma probes each comprise a compensation capacitor, the compensation capacitors having rated values that differ from each other by at least 10%, and wherein the difference in capacitance values of each intrinsic capacitance of the transmission line relative to each other is greater than the difference in capacitance values of the sum of the intrinsic capacitance and the compensation capacitor relative to each other.

[0028] According to an aspect of some embodiments of the present disclosure, the difference in capacitance value of the transmission line is reduced by at least two times or more in each sum of the intrinsic capacitance and the compensation capacitor capacitance.

[0029] According to an aspect of some embodiments of the present disclosure, the transmission lines differ in length from one another by at least 10 cm.

[0030] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this disclosure belongs.Although methods and materials similar or equivalent to those described herein can be used to practice or test the embodiments of this disclosure, exemplary methods and / or materials are described below.In case of conflict, the patent specification, including definitions, shall prevail.In addition, materials, methods, and examples are merely illustrative and are not necessarily intended to be limiting.

[0031] As will be appreciated by those skilled in the art, aspects of the present disclosure may be embodied as a system, method, or computer program product. Accordingly, aspects of the present disclosure may take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects, all of which may be commonly referred to as "circuits," "modules," or "systems" (e.g., a method may be implemented using "computer circuitry"). Furthermore, some embodiments of the present disclosure may take the form of a computer program product embodied in one or more computer-readable mediums having computer-readable program code thereon. Implementation of some embodiments of the methods or systems of the present disclosure may involve performing and completing selected tasks manually, automatically, or a combination thereof. Furthermore, depending on the actual instrumentation and apparatus of some embodiments of the methods and / or systems of the present disclosure, selected tasks may be implemented by hardware, software, firmware, and / or a combination thereof (e.g., using an operating system).

[0032] For example, hardware for performing selected tasks according to some embodiments of the present disclosure may be implemented as a chip or circuit. As software, selected tasks according to some embodiments of the present disclosure may be implemented as a plurality of software instructions executed by a computer using any suitable operating system. In some embodiments of the present disclosure, one or more tasks performed in the methods and systems are performed by a data processor (a data processor may also be referred to as a "digital processor" when referring to a data processor that operates using groups of digital bits), such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes volatile memory for storing instructions and / or data, and / or non-volatile storage, such as a magnetic hard disk and / or removable media, for storing instructions and / or data. Optionally, a network connection is also provided. Optionally, a display device and user input devices, such as a keyboard and mouse, are also provided. Any of these embodiments are more generally referred to as an instance of a computer circuit.

[0033] In some embodiments, any combination of one or more computer-readable mediums may be utilized. The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium may be, for example, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More specific examples (a non-exclusive list) of computer-readable storage media include an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. As used herein, a computer-readable storage medium refers to any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A computer-readable storage medium also includes information for use by such programs, e.g., data structured in a manner that allows the computer program to access the data, e.g., as one or more tables, lists, arrays, data trees, and / or other data structures. Here, a computer-readable storage medium that stores data as groups of digital bits is also referred to as a digital memory. It should be understood that in some embodiments, if a computer-readable storage medium is not inherently read-only and / or is in a read-only state, the computer-readable storage medium is also optionally used as a computer-writable storage medium.

[0034] Here, a data processor is "configured" to perform data processing actions to the extent that it is coupled to a computer-readable medium, receives instructions and / or data therefrom, processes them, and / or stores the results of the processing in the same or another computer-readable medium. Processing (optionally on data) is defined by instructions, and the processor operates in accordance with the instructions to perform the processing. The act of processing may additionally or alternatively be referred to by one or more other terms (e.g., comparing, estimating, determining, calculating, identifying, associating, storing, analyzing, selecting, and / or transforming). For example, in some embodiments, a digital processor receives instructions and data from a digital memory, processes the data in accordance with the instructions, or stores the results of the processing in the digital memory. In some embodiments, "providing" the results of the processing includes transmitting, storing, or presenting one or more of the results of the processing. Presenting optionally includes displaying the results on a display device, providing an audible indication, printing on a printed material, or providing the results in a form accessible to human sensory abilities.

[0035] A computer-readable signal medium may include a propagated data signal having computer-readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including electromagnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium, other than a computer-readable storage medium, that can communicate, propagate, or transport a program for use by or in connection with an instruction-execution system, an instruction-execution apparatus, or an instruction-execution device.

[0036] The program code and / or data embodied in the computer readable medium may be transmitted using any suitable medium, such as wireless, wire, fiber optic cable, RF, etc., or any suitable combination thereof.

[0037] Computer program code for carrying out operations for some embodiments of the present disclosure may be written in any combination of one or more programming languages, including object-oriented programming languages such as Java, Smalltalk, C++, etc., and conventional procedural programming languages such as the "C" programming language or similar programming languages. The program code may run entirely on the user's computer as a standalone software package, partially on the user's computer, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., via the Internet using an Internet Service Provider).

[0038] Some embodiments of the present disclosure may be described below with reference to flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block of the flowcharts and / or each block of the block diagrams, and combinations of each block of the flowcharts and / or each block of the block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing apparatus, and executed as instructions executed by the processor of the computer or other programmable data processing apparatus to form means for implementing the functions / acts specified in the flowcharts and / or block diagrams or blocks.

[0039] These computer program instructions may be stored on a computer-readable medium that can direct a computer, other programmable data processing apparatus, or other device to perform certain operations, such that the instructions stored on the computer-readable medium result in an article of manufacture that includes instructions that perform the particular functions / operations of the flowcharts and / or block diagrams.

[0040] The computer program instructions may be loaded into a computer, other programmable data processing apparatus, or other device and cause the computer, other programmable apparatus, or other device to perform a series of operational steps to create a computer-implemented process, such that the instructions executing on the computer or other programmable apparatus provide processing to implement the particular functions / operations of the flowcharts and / or block diagrams.

[0041] Some of the methods described herein are generally designed to be used solely by a computer and may not be feasible or practical to perform purely manually by a human expert. A human expert wishing to manually perform a similar task, such as inspecting an object, would be expected to use an entirely different method, e.g., utilizing specialized knowledge and / or the pattern recognition capabilities of the human brain, which may be much more efficient than manually proceeding through the steps of the methods described herein.

[0042] Several embodiments of the present disclosure are described herein, by way of example only, with reference to the accompanying drawings. With detailed reference to the following drawings, it is emphasized that the particulars shown are exemplary and are for the purpose of explaining embodiments of the present disclosure. Similarly, from viewing the description in conjunction with the drawings, it will become apparent to those skilled in the art how embodiments of the present disclosure may be practiced. [Brief explanation of the drawings]

[0043] [Figure 1]1 is a schematic diagram of a plasma generation device according to some embodiments of the present disclosure. [Figure 2] FIG. 1 is a schematic diagram of a resonant high-voltage plasma generation system according to some embodiments of the present disclosure. [Figure 3] FIG. 1 is a schematic diagram of a capacitor-calibrated transmission line of a plasma probe according to some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a system for variable capacitor compensation of the intrinsic capacitance of a transmission line of a plasma probe, according to some embodiments of the present disclosure. [Figure 5] FIG. 10 is a schematic diagram illustrating compensation of the intrinsic capacitance of a transmission line of a plasma probe with a selectable capacitor, according to some embodiments of the present disclosure. [Figure 6A] 1A-1C are schematic diagrams illustrating various methods of controlling multiplexed capacitor compensation of the intrinsic capacitance of a transmission line of a plasma probe, according to some embodiments of the present disclosure. [Figure 6B] 1A-1C are schematic diagrams illustrating various methods of controlling multiplexed capacitor compensation of the intrinsic capacitance of a transmission line of a plasma probe, according to some embodiments of the present disclosure. [Figure 6C] 1A-1C are schematic diagrams illustrating various methods of controlling multiplexed capacitor compensation of the intrinsic capacitance of a transmission line of a plasma probe, according to some embodiments of the present disclosure. [Figure 7] FIG. 1 is a schematic diagram of a system for port-selectable capacitance compensation of the intrinsic capacitance of a transmission line of a plasma probe, according to some embodiments of the present disclosure. [Figure 8] FIG. 1 is a schematic diagram of a system for providing impedance selection with multiple transformers for use in the final transformer stage of a plasma power supply in accordance with some embodiments of the present disclosure. [Figure 9] FIG. 1 is a schematic diagram illustrating a method for automatically compensating for capacitance of a plasma probe according to some embodiments of the present disclosure. [Figure 10]FIG. 1 is a schematic diagram illustrating a method for automatically correcting capacitance of a plasma probe according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0044] Some embodiments of the present invention relate to the field of plasma generation, and more particularly to the design of plasma power sources.

[0045] overview An aspect of some embodiments of the present disclosure relates to modifying and / or controlling the characteristics of an output of a plasma power generation unit. In some embodiments, the output comprises multiple transformer stages. In some embodiments, the operating characteristics of the output (e.g., operating frequency) are due in part to the impedance of the transmission line (e.g., capacitance, which may be proportional to length).

[0046] In some embodiments, the operating characteristics of the plasma power generation unit's output are necessarily affected by the impedance of the transmission line. That is, they are not just a design choice, but actually operate differently depending on the characteristics of the transmission line to which they are currently connected. The impact on operating characteristics may be manifested, for example, by a change in the transmission line impedance, which immediately affects the plasma power generation unit's ability to generate a signal suitable for efficient plasma generation at some point in the circuit. The signal may be prevented entirely, and / or its characteristics, such as frequency and / or amplitude, may be altered from a range useful for plasma generation. For example, in some embodiments, a feedback signal from the plasma power generation unit's output is used to synchronize the oscillation of a previous stage of power generation. If the output cannot respond at the appropriate frequency, the previous stage, lacking feedback, will also be unable to generate. The impact on operating characteristics may be distinguished from impedance matching itself. That is, a signal is generated regardless of the transmission line impedance, but matching the impedance of the generation circuit and the transmission line allows the signal to travel more efficiently down the transmission line without being reflected back to the power generation unit.

[0047] In some embodiments, the transmission line is an element of a plasma delivery probe. The plasma delivery probe is long, thin, and flexible (e.g., catheter-like and / or wire-like in structure) and can be introduced into a body cavity by pushing it from a proximal location. The probe typically includes a discharge gas conduit that extends along the conductive element of the transmission line and leads to a plasma generation site at the distal end of the plasma probe where the discharge gas interacts with the transmitted electrical signal to generate plasma. Additionally or alternatively, the discharge gas may be introduced by other methods, such as through the lumen of a second probe.

[0048] In some embodiments, the plasma delivery probe generates a non-thermal atmospheric plasma (NTAP), also called a "cold" plasma. Generally, the temperature of the non-thermal plasma should be maintained below 50° C. Alternatively, it should be maintained at a lower temperature, for example, below 40° C. or below 30° C.

[0049] To be effective in generating a plasma, the signal generated (and transmitted along the transmission line to the site of plasma generation) is, in some embodiments, a relatively high voltage (e.g., 500 V or greater). For suitably efficient plasma generation, the signal frequency may range, for example, from about 500 kHz to about 10 MHz. At lower frequencies, plasma generation may tend to be intermittent and extinguish due, for example, to shielding by mobile charged species, reducing efficiency. At lower voltages, plasma may not be generated at all.

[0050] In some embodiments, where the transmission line impedance inherently affects the operating characteristics of the output section, this occurs because the transmission line capacitance provides part of the inductance of a resonant LC circuit that provides frequency-locked feedback to the preceding stage of power generation. These operating requirements can be a significant constraint on the design of the power generation circuit, especially when the transmission line is tens of centimeters long (e.g., 50 cm to 2 m).

[0051] In particular, other things being equal, the longer the selected transmission line length, the greater the contribution of the transmission line's impedance (e.g., capacitance). This tends to increase the time constant of any particular LC circuit of which the transmission line is a part. In some embodiments, this poses particular design challenges in providing a sufficiently high level of operating frequency for efficient plasma generation. The output stage should generate a relatively high voltage gain (e.g., an overall gain of 20-50) relying on the transformation by the coil, while also maintaining a high resonant frequency. However, the requirement for high frequency implies a relatively low output (secondary) coil inductance (so that the LC time constant is low), and the requirement for high gain tends to drive this even lower in the input (primary) coil. In a single transformer stage implementation, this can result in a theoretical circuit requiring a low-impedance coil that, in practice, cannot handle the required power and / or voltage slew rate.

[0052] Some embodiments of the present disclosure address this by splitting the output stage into two or more transformer stages. This isolates the earlier stages from the high capacitance of the transmission line and allows higher impedance transformers to be selected to generate gain. Once the gain requirement is addressed, the later stages can use nearly equal (or at least more equal) transformer coils on both the input and output sides, eliminating the need to make the input transformer coil impractically small.

[0053] The impedance of a transmission line not only varies with length, but may additionally or alternatively vary based on other structural aspects, such as the cross-sectional shape and / or material of the transmission line cable. Normal variations in transmission line manufacturing can also result in differences in electrical characteristics, such as cable impedance. It should be noted that plasma probes, in some embodiments, are considered consumables (e.g., to avoid complications such as resterilization). Therefore, instead of calibrating the probe to the power supply at the factory, there may be a practical requirement to allow many different probes to be used with the same power supply, such as probes manufactured as part of different batches (e.g., probes with different cable origins) and / or different versions or models of probes.

[0054] If the internal electrical characteristics of the transmission line change (e.g., as a result of changing or replacing components and / or in terms of manufacturing tolerances), the same power output characteristics (e.g., the same amplitude and / or frequency of power output) may be maintained for the entire circuit if one or more other circuit components are changed.

[0055] However, when circuit design constraints are very tight, there is little freedom to make such changes. This can require the transmission lines to be manufactured to inconvenient (or practically impossible) tight tolerances. We have found that the design freedom created by separating the responsibilities of the output stage (high gain and high-frequency resonance involving the capacitance of the transmission line) creates more freedom to allow for variations in the impedance of the transmission line. Additionally or alternatively, one may exploit the additional freedom in component characteristics to adjust power signal characteristics such as frequency.

[0056] For example, in some embodiments, this degree of freedom is used by providing a final transformer stage with a coil inductance lower than the required inductance to achieve frequency matching with some practically manufacturable transmission line of the required length, allowing it to function with a wider range of transmission lines. In effect, the inductance of the final stage sets the maximum capacitance of the transmission line with which the output stage can interface.

[0057] In some embodiments, the transmission line of the plasma probe is "aggravated" by adding (e.g., during manufacturing and / or calibration) only the additional capacitance necessary to couple with the impedance of the final transformer stage to resonate at the target operating frequency. The highest capacitance transmission line does not require any additional capacitance. This can contribute to improved manufacturability of the plasma probe, as variations in probe capacitance can be trimmed out.

[0058] In some embodiments, "excess capacitance" is provided as part of the plasma power generation section. For example, there may be a variable capacitor, or multiple capacitors (fixed or variable over different ranges). The capacitor selection / adjustment depends on the characteristics of the connected plasma probe and its transmission line.

[0059] If multiple capacitors are provided, the capacitors may be selected by selecting the port of the power supply to which the plasma probe is connected and / or by an internal multiplexer (e.g., a multiplexing integrated circuit, a bank of relay switches, or other implementation). The internal multiplexer may perform the capacitor selection under the control of a user interface. The user interface may be mechanical (e.g., a rotary switch) or electronic (e.g., a graphical user interface (GUI)).

[0060] Additionally or alternatively, the selection may be automatic. For example, each plasma probe may be provided with a digital or analog (e.g., resistive) identifier, and when the plasma probe is plugged in or placed in communication with the power output generator, a multiplexer may be controlled to select a selected auxiliary capacitance in response to the identifier.

[0061] In some embodiments, the selection of the auxiliary capacitance is done automatically based on feedback from actual circuit performance. For example, the probe is induced to oscillate with the test circuit, and the actual working capacitor is selected according to the oscillation frequency found by the test. In some embodiments, the test circuit is simply a normal plasma generation circuit. In some embodiments, a separate test circuit is provided.

[0062] In some embodiments, output stage circuit tuning is provided by adjusting the inductance of at least the last transformer stage. For example, multiple transformers, each with a different secondary inductance, are provided and selected by multiplexing. To this end, a single primary coil may be provided with multiple selectable secondary coils, or a different transformer may be selected for each configuration. Optionally, the inductance of the coil may be variably selected, for example, by selecting different taps on the same coil. Transformer selection has the potential advantage of not requiring the addition of excess capacitance, allowing for the selection of a more robust transformer if the transmission line capacitance is low enough to allow for it.

[0063] Other uses of selectably matched transmission line and output stage impedances include, for example, the selection of variable output frequencies as a way of controlling plasma power.

[0064] By using two or more transformer stages in the output stage, the feedback signal to the previous stage in generating the power signal is potentially less sensitive to changes in transmission line impedance. Roughly speaking, each additional transformer stage in the output stage has its own natural resonant frequency, which combines in a weighted manner between the transformer stages to generate the frequency of the feedback signal. The feedback signal must be within the range that the earlier generating stages can accept, or it will fail to generate an oscillating power signal. With more transformer stages, the relative weighting of the final transformer stage becomes lower. Increasing the gain of the final transformer stage above unity tends to exacerbate this effect.

[0065] Note that as a result of the reduced weighting of the final transformer stage, the change in transmission line capacitance shifts the resonant frequency of the final transformer stage more than the operating frequency of the power output generator. This reduces transmission efficiency, as with a normal impedance mismatch, even if the power signal itself continues to be generated. However, the impact of this loss in transmission efficiency can still be mitigated by providing a range of selectable impedances to bring the resonant frequency of the final transformer stage within an acceptable range near the frequency optimum. Maintaining efficiency is useful for enabling portability of the power source (e.g., battery powered) and / or reducing component stress due to heating.

[0066] Before describing at least one embodiment of the present disclosure in detail, it is to be understood that the disclosure is not necessarily limited in its application to the details of construction and the arrangement of components and / or methods set forth in the following description and / or illustrated in the drawings. Features described in the present disclosure, including features of the present invention, can be implemented in other embodiments or can be carried out in various ways.

[0067] Plasma Treatment Device Reference is made to FIG. 1, which schematically illustrates a plasma generation device 100 according to some embodiments of the present disclosure.

[0068] In some embodiments, the plasma generation apparatus 100 includes a high-voltage power generator 201 and an ionized gas supply 61 interconnected to a plasma probe assembly 62. The high-voltage power generator 201 supplies an ionizing voltage to the plasma probe assembly 62 via a cable 203 (e.g., a coaxial cable or other impedance-controlled electrical conduit). The ionized gas supply 61 supplies an ionized gas to the plasma probe assembly 62 via tubing 72. The supplied gas may include, for example, one or more noble gases, such as neon, argon, or helium, and / or other gases suitable for ionization into the plasma plume 90. Optionally, the cable 203 and the tubing 72 are integrated into a single cable unit that connects to the plasma probe assembly 62. Optionally, the high-voltage power generator 201 and the ionized gas supply 61 are housed together.

[0069] The plasma probe assembly 62 optionally includes a handle 80. The handle 80 optionally includes controls 81, 82 for controlling operation of the probe conduit 73 and / or the plasma delivery tip 66, and / or for controlling the function of the power generation section 201, and / or for controlling the delivery of ionized gas from the gas supply 61. Optionally, the plasma probe assembly 62 physically integrates power and gas delivery functions into the probe conduit without using a dedicated handle. In some embodiments, the probe conduit 73 includes a lumen for delivery of ionized gas and a high-voltage transmission line (e.g., an extension of the cable 203 and tubing 72). In some embodiments, the probe conduit includes multiple lumens, such as a lumen attached to the gas supply 61 that supplies ionized gas, and optionally a lumen for collecting (removing) the ionized gas under suction. In some embodiments, one or more of the lumens in the probe conduit 73 are optionally used as a working path by insertion of a tool. The handle 80 , in some embodiments, includes one or more ports 83 for introducing such tools into the lumen of the probe conduit 73 .

[0070] In some embodiments of the present invention, the probe conduit 73 and plasma delivery tip 66 are sized and otherwise configured (e.g., safety settings) to deliver non-thermal plasma to an intrabody location. The intrabody location may be remotely located relative to the insertion point, e.g., 25 cm or more from the point of insertion into the body, e.g., 50 cm, 80 cm, 100 cm, or 120 cm. In some embodiments, the reachable range includes at least a range of 50 cm to 100 cm. To the extent that the plasma tip 60 comprises the site of plasma generation (as in some embodiments), the device must supply ionization-level voltages (e.g., voltages of 1 kV or greater) to the tip 60. This length may impose constraints on the minimum capacitance of the cable 203.

[0071] In some embodiments, the probe conduit 73 (including both the lumen for delivery of ionized gas and the high voltage transmission line) has an overall diameter of less than 12 mm, less than 10 mm, less than 8 mm, or less than 5 mm. The narrower the overall diameter, the narrower the minimum size body cavity through which the probe conduit can pass, such as a catheter. For example, a ureter, blood vessel, or other subcutaneous access route to the target treatment site.

[0072] Power supply output stage having multiple transformer stages Please refer to FIG. 2. FIG. 2 schematically illustrates a resonant high-voltage plasma generation system 300 according to some embodiments of the present disclosure. The generator 301 divides the task of providing voltage gain and coupling to the plasma probe 62 into two transformer stages: a gain transformer 305A and a decoupling transformer 305B. Optionally, more than two transformer stages are used. For the purposes of discussion, stages beyond the first transformer stage will be considered part of the "decoupling transformer" (although any or all of them may provide some gain). The transformer stage that connects to the plasma probe 62 without another transformer stage is the "final transformer stage."

[0073] In some embodiments, this allows for driving relatively high capacitance loads while retaining the potential advantages of a resonant architecture for achieving high frequency and potentially true sinusoidal output while generating plasma.

[0074] Considering the driver circuit 204 in combination with the gain transformer 305A, basic resonance is achieved by matching the time constant of the LC network of the gain transformer with the feedback LC network in the driver circuit 204. The capacitance of the LC network of the gain transformer can be selected to be small (e.g., within 10 times 1-5 pF). This allows the inductance of the corresponding secondary coil to be substantially high. This allows the capacitance of the plasma probe transmission line 203, when directly connected to the gain transformer, to fall within a practical range, potentially enabling previously unobtainable gain at frequencies of, for example, 1-2 MHz, and allows the inductance of the primary coil and / or feedback coil to be substantially high.

[0075] The remainder of the circuit delivers the high frequency, high voltage signal to the load. Decoupling transformer 305B, if it has only a single stage, has a primary inductance connected to gain transformer 305A and a secondary inductance connected to the plasma probe (e.g., via connectors 220 and 221).

[0076] Optionally, this transformer is set for unity gain. The inductance is arbitrarily selected, for example, within a range of approximately 10 times 100 μH, i.e., within a range of 20 to 200 μH. Alternatively, this transformer is used as a second stage gain. For example, the primary coil can be set in the range of 5 to 20 μH, and the secondary coil can be set in the range of approximately 20 to 80 μH. For example, it can be set to achieve an effective second stage gain of 1 to 4 (e.g., 2). The LC network (including the capacitance of transmission line 203) on the secondary (output) side of the transformer is configured to match the resonant frequency provided to driver circuit 204 and gain transformer 305A.

[0077] This configuration allows for some relaxation of the frequency-to-gain coupling by providing additional design freedom. For example, the coaxial cable length is less restricted and can be longer, and because the gain does not have to be provided entirely in the transformer stage, the inductance of the primary coil can be as large or nearly as large as the secondary coil selected to pair with the transmission line capacitance. Variations among other plasma probes 62 may result, for example, from cable construction and / or manufacturing variations.

[0078] In some embodiments of the present disclosure, a lower final stage inductance is selected that is practically feasible for the voltage, frequency, and current requirements, while still leaving a "headroom" to accommodate different transmission line capacitances.

[0079] Compensation element in the probe Referring to FIG. 3, a schematic diagram of a capacitor-calibrated transmission line for a plasma probe is shown, in accordance with some embodiments of the present disclosure.

[0080] The output from the power supply 301 is conducted to a supply connector 220 to which a plasma probe connector 221 is electrically connected. The compensation capacitor 321 is installed during manufacturing so that the sum of the capacitance 303 of the transmission line 203 and the compensation capacitor 321 reaches a target value.

[0081] This may be a single value (or a value within a single uninterrupted tolerance range) that the fixed components of power supply 301 are configured to accept. "Accept" in this context means, for example, that the resonant frequency of decoupling transformer 305B, coupled with the total capacitance of compensation capacitor 321, the intrinsic capacitance 303 of transmission line 203, is reasonably close to the designed operating frequency of the overall system for operation.

[0082] Here, the capacitance of a compensation capacitor (also called a compensation element, which may thus "compensate" an LC circuit or the like to produce a predetermined characteristic, particularly, in some embodiments, the characteristic of having a predetermined resonant frequency), however selected or provided (e.g., according to any of the embodiments described herein), is considered its rated capacitance; that is, the capacitance that is taken into account in selecting it as a component during device manufacture. Two capacitors with the same rated capacitance may, for example, be marked the same as originally manufactured, or "binned" after acceptance testing at the manufacturing site.

[0083] Here, "adequately close" includes, in some embodiments, that the deviation of the uncompensated probe's intrinsic capacitance from the target capacitance, when considered together (additively) with the capacitance of the compensation capacitor, is reduced by a factor of at least 2x, 5x, 10x, or other value. In some embodiments, the compensation capacitance difference used in different probes can be proportional to the shortfall in length relative to the longest transmission line supported (at least on average across production runs). In some embodiments, the values of compensation capacitors (however selected or provided) used in different probes of nominally the same length and construction can differ from each other by at least 10%, at least 20%, at least 40%, at least 50%, or other values.

[0084] For example, power supply 301 may be configured with a certain load capacitance C that has been identified as the preferred (e.g., optimal) capacitance for the performance and operating frequency of interest. Coax{target} The transmission line may be configured to receive a transmission line having a C Coax{target} may be defined with an appropriate tolerance, for example, within ±0.1% of the center value, or ±1%, ±2%, ±5%, or other tolerance range. Coax{target}If the capacitance is lower than the value and / or range defined in C, the difference is made up by the added capacitance of capacitor 321. Therefore, regardless of the cable used, C Coax+ C Connector =C Coax{target} (within tolerance).

[0085] For example, power supply 301 is configured to drive a 300 pF capacitive load at 1 MHz, corresponding to a 3 meter coaxial cable, which represents the maximum capacitance cable in a particular system configuration. The 3 meter plasma probe 62 does not have an integrated compensating element 321. For a shorter 2 meter probe (e.g., measuring 200 pF capacitance), C Connector A =100pF compensation element is built into the connector, giving a total capacitance of 300pF.

[0086] In this way, the resulting resonant frequency remains the same for different types and / or lengths of plasma probe transmission line 203. As long as the total power output is frequency dependent, other parameters being equal, the power output will be the same for all probe models.

[0087] As shown, compensation capacitor 321 is incorporated at the plug end of transmission line 203. Additionally or alternatively, compensation capacitor 321 (or a portion of its capacitance) is incorporated at the distal end (plasma generation end) of the transmission line.

[0088] Compensation capacitor 321, in some embodiments, comprises a discrete capacitor electrically connected (e.g., soldered) in parallel to the transmission line. Alternatively, since practically all connectors introduce at least some parasitic capacitance into the line, connector 221 itself may be designed to provide all or part of the compensation capacitance. This, in some embodiments, involves the selection of the structure of metal surfaces and dielectric materials within the connector to achieve the required compensation value.

[0089] In some embodiments, several tolerances are made available and / or the tolerances themselves are somewhat adjustable by combining the per-probe capacitance calibration of FIG. 3 with one or more of the methods of FIGS. 3-8.

[0090] In some embodiments, if the length of the plasma probe is not a critical parameter (at least within a tolerance), the transmission line of the plasma probe is simply shortened until the intrinsic capacitance matches some target value. The tolerance range can be chosen to be wide enough in practice to avoid an acceptable number of defective units, yet narrow enough to avoid compromising usability and / or the user's perception of quality. For example, the nominal usable length of the transmission line may be 2 meters, but the actual provided length may be within a wider range, e.g., 2-3 meters. Optionally, the excess length is wrapped and bundled to avoid an overly irregular appearance, or hidden inside a connector with sufficient space to accommodate a significant amount of excess length. In some embodiments, the plasma probe is provided as a set (e.g., shipped, stored, or otherwise provided together) including individual units with approximately the same intrinsic capacitance but with transmission line length differences of 10 cm, 20 cm, 30 cm, or more. In some embodiments, up to 10 cm, 20 cm, 30 cm, or more of the transmission line length is covered by or actually hidden by permanently wrapping and / or hiding the excess in a connector housing or other container, such as a housing located along the length of the transmission line, preferably near the proximal end of the transmission line. In some embodiments, the plasma probe length is adjusted after adjustment with an in-probe compensation capacitor. For example, the plasma probe is provided with a compensation capacitor that brings the total capacitance slightly above a target value, and a shortened transmission line is provided to lower the capacitance in a controlled manner to achieve the target value.

[0091] In some embodiments, the power supply may be configured to operate within a selectable frequency range from multiple different available operating frequency ranges. For example, different frequency ranges may be suitable for providing different amounts of plasma power. In some embodiments, the plasma probe is provided as a set including individually configured probes with distinct capacitances using different compensation capacitor values. In some embodiments, the compensation capacitance is provided as an add-on to the probe. For example, in some embodiments, a kit is provided that includes multiple adapters that provide different compensation capacitances.

[0092] Additionally or alternatively, an add-on compensation capacitance adapter (e.g., from a kit such as those described above) may be used to adjust probes having different capacitances (e.g., probes provided with a probe kit) to more closely match each other, e.g., to resonate at a common frequency when connected to a power supply, but conversely, to resonate at a different frequency when the add-on adapter is not used. For example, it may be useful to allow multiple probes with different original adjustments to be used simultaneously from different ports on a power supply.

[0093] In-generator compensation element FIG. 4 illustrates a schematic of a system for compensating the intrinsic capacitance of a transmission line of a plasma probe 62 with a variable capacitor, according to some embodiments of the present disclosure.

[0094] The variable capacitance 421 can be selected from among a number of discrete capacitances, and Figures 5-7 show several different ways of implementing such a system.

[0095] In some embodiments, the variable capacitor 421 is a continuously variable capacitor provided as part of a capacitance control system 401 that allows the variable capacitor 421 to be mechanically or electrically (e.g., voltage and / or digitally) adjustable, depending on its type (several types of variable capacitors are known in the art). Thus, the capacitance control system 401 can implement variable capacitance control via a mechanical control (e.g., knob) and / or a computerized graphical user interface. In particular, for an electrically adjustable variable capacitor, the variable capacitor 421 and adjustment controller 401 together can be used in place of a multiplexer-capacitor bank, as described, for example, with respect to FIGS. 6A-6C. Motor-driven automatic mechanical adjustment of the capacitance control system 401 is also an option.

[0096] Referring to FIG. 5, FIG. 5 schematically illustrates selectable capacitor compensation of the intrinsic capacitance of the transmission line of the plasma probe 62, according to some embodiments of the present disclosure.

[0097] 5 illustrates a mechanical method of selecting from multiple individual capacitors in capacitor bank 521 by mechanically adjusting the setting of rotary selector 522, either manually or (optionally) by motor drive. Each capacitor in capacitor bank 521 corresponds to a different value that is added to the intrinsic capacitance 303 of transmission line 203.

[0098] To provide a wider range of choices, one or more capacitors may optionally be selected in combination. For example, multiple capacitor banks 521 may be provided, each selected by a different rotary selector 5220. One bank may select from a range of smaller capacitor values, and the other bank may select from a range of larger capacitor values. This allows the combination of two banks to subdivide the overall range even further.

[0099] 6A-6C, which schematically illustrate various methods for controlling multiplexed capacitor compensation of the intrinsic capacitance of the transmission line of the plasma probe 62, according to some embodiments of the present disclosure.

[0100] In the example of Fig. 6A, a signal selected via GUI 602 controls multiplexer 622 to select one of the capacitors in capacitor bank 621. In the case of Fig. 5, there are multiple capacitor banks 621, and capacitors may be selected from multiple capacitor banks 621 and used in combination.

[0101] In the example of Figure 6B, connector 221 is provided with an identification element 603. Following automatic identification, the system automatically sets the compensation capacitance appropriate for the probe.

[0102] In some embodiments, the identifier is an identification resistor R that connects to an identification circuit in the controller 605 when the connector 221 is plugged into the power connector 220. Identifier The resistance value may be, for example, in the range of 1 to 10 kΩ. In some embodiments, the identifier value is different for probes of different lengths, models, and / or types. When a probe is plugged into the generator, the identifier is measured by a decoding portion of the controller 605, and the controller 605 selects the correct compensation capacitance, for example, via a control line and a switch, e.g., via a control line to multiplexer 622. In some embodiments, R Identifier The value of R is chosen to directly indicate which compensation capacitor to select from the capacitor bank 621. In some embodiments, R Identifier The value of is selected to be proportional to the value of capacitance 303, with a compensation capacitor selected accordingly.

[0103] In some embodiments, other types of identifiers are used, such as Radio Frequency Identification (RFID) tags, or other numerically encoded identifiers, such as EEPROMs wired to the probe contacts, or optically encoded identifiers.

[0104] Referring now briefly to FIG. 10, FIG. 10 schematically illustrates a method for automatically compensating for plasma probe capacitance, according to some embodiments of the present disclosure. At block 1010, in some embodiments, a plasma probe equipped with an identifier element is connected to a plasma power supply. At block 1012, in some embodiments, the identifier of the connected probe is accessed and the plasma probe is identified accordingly. At block 1014, in some embodiments, a compensation capacitance (and / or, in some embodiments, an appropriate transformer impedance) is selected based on the identification of the connected probe, which identification is also associated with the expected capacitance value of the connected probe. The compensation is selected such that the operating frequency of the power supply is within an available range and / or a closed range relative to the target operating frequency of the power supply and the target operating frequency of the plasma probe.

[0105] In the example of FIG. 6C, the adjustment of the compensation capacitance is automatically managed based on frequency sensing.

[0106] In some embodiments, a frequency measurement circuit 632 (preferably having low input capacitance) is connected in parallel with the output of power supply 301. Upon initiation of the high voltage oscillating signal, frequency measurement circuit 632 measures the generated frequency. The measurement is provided to control circuit 631, which selects (e.g., via a control signal sent to multiplexer 622) an appropriate compensation capacitor to trim the frequency to within a desired margin of the target value or other defined range. Optionally, if the line impedance changes during plasma application, frequency measurement circuit 632 detects the change in resonance, and control circuit 631 compensates accordingly.

[0107] Optionally, conversely, some embodiments control power by intentionally “detuning” the resonant frequency. In such embodiments, the control circuit 631 operates to select capacitors from the capacitor bank 621 that result in a resonant frequency that interacts inefficiently with the power supply 301. This can be used to modulate power, which can be treated as a measure of the dosage rate. Over relatively long periods (e.g., milliseconds to seconds), the average power can be controlled by switching between multiple capacitors at a high frequency duty cycle. This allows for relatively fine power control, even if only by switching between two different operating frequencies: an efficient frequency and an inefficient frequency. Measurements by the frequency meter circuit 632 may be used to verify performance or as input to help estimate, for example, actual power, dosage rate, and / or cumulative dosage and / or plasma energy.

[0108] The frequency measurement circuit 632 may additionally or alternatively be used for plasma emission malfunction detection and / or monitoring. For example, if the initial frequency measurement exceeds known process / probe variations, this may be reported as a failure because it is due to a malfunctioning probe, which is likely a malfunction. This may be caused by a short circuit (e.g., a shorted probe) or an open circuit (e.g., a missing or disconnected probe). Optionally (possibly even after capacitance compensation), it may be determined that the operating frequency and plasma probe are both operating at an efficiency other than (e.g., lower than) the target efficiency (e.g., efficiency measured in terms of plasma-generating power), but still sufficiently effective (generating sufficient plasma) for basic operation. For example, the actual effectiveness of plasma generation may be determined to be, for example, 80%, 90%, or 95% of the nominal (e.g., target) efficiency. Potentially, the effectiveness may even exceed 100% of the nominal efficiency (e.g., if the nominal efficiency is set lower than the maximum achievable efficiency). In some embodiments, the difference between the target efficacy and the actual efficacy is further compensated for by adjusting, for example, one or more of the plasma exposure time, plasma scan rate, ionized gas composition and / or flow rate, applied ionization voltage, and / or other parameters of the plasma generation.

[0109] A short circuit condition may result in the termination of oscillation of the power signal, for example, due to the lack of a feedback signal of the appropriate frequency to synchronize power generation. The lack of oscillation may be detected by a frequency meter, which may trigger an associated safety circuit, for example, by a signal sent from control circuit 631 to power supply 301.

[0110] Similarly, an open circuit condition along the transmission line can result in a sudden increase in the oscillation frequency. Optionally, detection of such a frequency increase (e.g., exceeding a predefined threshold) can activate a safety circuit. If the increase in resonant frequency manifests as a cessation of oscillation of the power signal, this also triggers activation of the safety circuit. In some embodiments, triggering the safety circuit stops the generation of the power signal. Optionally, the open circuit condition simply triggers the selection of a capacitor with the nominal maximum value of capacitance required to continue power generation.

[0111] Furthermore, application of the plasma to a conductive and / or capacitive target can result in a gradual decrease in oscillation frequency. This can be due, for example, to increased current draw from the generator. In some embodiments, the frequency change is measured and interpreted as an indicator correlating to the amount of power applied at the plasma end of the probe. While not necessarily accurate as an indicator of absolute power delivery (e.g., because target characteristics affect its magnitude), frequency change measurements can be cross-referenced with other power measurement techniques to improve the overall accuracy and reliability of power output measurements. Frequency variations can also be useful as operator feedback to indicate the spatial relationship between the probe and target.

[0112] Referring now briefly to FIG. 9, FIG. 9 schematically illustrates a method for automatically compensating for capacitance of a plasma probe, according to some embodiments of the present disclosure. At block 910, in some embodiments, a plasma probe equipped with an identifier element is connected to a plasma power supply. At block 912, in some embodiments, the power supply is activated along with the plasma probe. At block 914, in some embodiments, the actual operating frequency of the power supply and plasma probe is measured. At block 916, in some embodiments, a compensation capacitance (and / or, in some embodiments, an appropriate transformer impedance) is selected based on the measured frequency. The compensation is selected such that the operating frequency of the power supply is within an available range and / or a closed range relative to the target operating frequency of the power supply and the target operating frequency of the plasma probe.

[0113] Referring to FIG. 7, a system for port-selectable capacitance compensation of the intrinsic capacitance of a transmission line of a plasma probe 62 is shown, in accordance with some embodiments of the present disclosure.

[0114] In some embodiments, the housing 302 of the power supply 301 is provided with multiple supply connectors 220, each connected to a different compensation capacitance 721A-721C. Depending on the respective intrinsic capacitances 703A-703C (examples of capacitance 303) of the plasma probe transmission lines 203, typically one plasma probe 62 is plugged in and used at a time.

[0115] Optionally, two or more ports are occupied at a time (linked in parallel to the power supply 301). If the power handling capacity of the power supply 301 is sufficient, power may be transferred through each connected probe. In some embodiments, disconnected ports are connected to a "dummy" load (disconnected by and / or upon probe installation) that oscillates but is not actually a plasma probe. This may result in the power supply maintaining oscillation when no plasma probe is connected. For example, this may be used to allow dynamic plugging of plasma probes into any number of ports, allowing, for example, multiple plasma probes to be used simultaneously, in which case converting to single-probe use is simply a matter of removing the additional plasma probe. Optionally, the pseudo port is provided with a permanently attached capacitance to permanently provide an oscillation feedback signal, regardless of whether a plasma probe is attached.

[0116] Optionally, the probes are manufactured with different plug keying and / or color coding on the connector to make it clear which probe should mate with which supplying connector 220.

[0117] Optionally, transformers (or at least the secondary coils of the transformers) with different inductance values are individually connected to different supply connectors 220. This offers the potential advantage of reaching higher frequencies with shorter (or otherwise lower capacitance) probes if the circuit, e.g., the circuit of the power supply 301, is tunable and / or has a sufficiently wide spectrum of operating frequencies. For example, a higher frequency of operation may provide an efficiency gain that justifies preferring a shorter plasma probe transmission line 203 when practical. The multi-port approach (each supply connector is considered a single port) may be combined with any other scheme for capacitance and / or inductance selection, e.g., as described herein, to support selecting compensation over a larger and / or finer selectable range. For example, there may be a high-compensation range port and a low-compensation range port. Each of the high-compensation range port and the low-compensation range port is associated with a respective selectable capacitor bank or adds a different fixed capacitance to a shared selectable capacitor bank.

[0118] Referring to FIG. 8, a system for providing impedance selection with multiple transformers for use in the final transformer stage of a plasma power supply 301 is shown schematically, in accordance with some embodiments of the present disclosure.

[0119] In some embodiments, multiple selectable transformers 833A-833C are provided within the decoupling transformer stage 305B of the power supply 301. Although only one transformer stage (the final stage) is shown within the decoupling transformer 305B block, other transformer stages may optionally be provided between the gain transformer 305A block.

[0120] In some embodiments, transformer selection is performed by port selection used by multiplexers (and / or relay sets) 831, 832, 834, 835 under control of controller 834. In the illustrated example, both primary and secondary coils are selected, but this is not necessarily the only operable topology, depending on the range of available components and corresponding transmission line capacitances and / or operating parameters. For example, the transformer may be provided with multiple taps, and tap selection may be adjustable on one or both sides of the transformer, and may be selectively, ganged, or independently adjustable.

[0121] The controller 834 may operate based on any suitable selection principle to match the transmission line capacitance 303 to an appropriate compensation component, for example based on one of the principles described in connection with Figures 6A-6C. Additionally or alternatively, a selection principle described in connection with one or more of Figures 3-5 and 7 is used.

[0122] In some embodiments, transformer options are selected to help maintain a relatively constant frequency and / or power output across the range of various probes. Additionally or alternatively, they may be selected to change the operating frequency of a particular connected probe. Modifying the transformer and / or transformer characteristics also offers potential advantages by allowing for changes in voltage gain, which is another way to adjust plasma-generating power, whether or not a constant operating frequency is maintained. For example, two transformers with different primary coil inductances and identical secondary coil inductances may result in two different gain settings but similar resonant frequencies.

[0123] General matters As used herein, "about" means "within ±10%" with respect to an amount or value.

[0124] The words "comprises," "comprising," "includes," "including," "having," and their conjugations mean "including, but not limited to."

[0125] The term "consisting of" means "including and limited to."

[0126] The term "consisting essentially of" means that a composition, method, or structure may include additional ingredients, steps, and / or moieties, provided that the additional ingredients, steps, and / or moieties do not materially alter the basic and novel characteristics of the claimed composition, method, or structure.

[0127] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. For example, "a compound" or "at least one compound" includes a plurality of compounds, and may also include mixtures thereof.

[0128] The words "example" and "exemplary" are used herein to mean "serving as an example, instance, or illustration." An embodiment described as "example" or "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments and / or does not necessarily exclude features of other embodiments from being incorporated.

[0129] "Optionally" is used herein to mean "provided in some embodiments and not provided in other embodiments." Any specific embodiment of the present disclosure may include multiple "optional" features except where such features are incompatible.

[0130] As used herein, the term "method" means manner, means, techniques, and procedures for accomplishing a given task, including, but not limited to, those known to practitioners in the fields of chemistry, pharmacology, biology, biochemistry, and medicine, or those that can be readily developed by practitioners from known manners, means, techniques, and procedures.

[0131] As used herein, the term "treating" includes arresting, substantially inhibiting, slowing, or reversing the progression of a condition, substantially ameliorating the clinical or cosmetic symptoms of a condition, or substantially preventing the worsening of the clinical or cosmetic symptoms of a condition.

[0132] Throughout this application, various embodiments may be presented in a range format. It should be understood that the description in range format is merely for convenience and brevity and is not an inflexible limitation on the scope of the descriptions in this disclosure. Thus, the description of a range should be considered to specifically disclose all of the possible subranges and individual numerical values within that range. For example, description of a range such as 1 to 6 specifically discloses subranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., as well as individual numerical values within that range, e.g., 1, 2, 3, 4, 5, and 6. This applies regardless of the magnitude of the range.

[0133] When a range of values is provided herein (e.g., any pair of numbers connected by "10-15," "10 to 15," or other range designations), it is intended to include any number (fractional or integer) within the limits of the range provided, unless the context clearly dictates otherwise. The phrases "range between" a first designated number and a second designated number, and "range," "range to," "range to," or "range including" (or other similar range terminology) "from" a first designated number to a second designated number, are used interchangeably herein and are meant to include the first and second designated numbers and all fractional and integer values therebetween.

[0134] While this disclosure has been described in conjunction with specific embodiments thereof, many alternatives, modifications, and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications, and variations that fall within the spirit and broad scope of the appended claims.

[0135] It should be understood that certain features of the present disclosure, which are for clarity described in the context of separate embodiments, may also be provided in any combination of these features in a single embodiment. Conversely, multiple features of the present disclosure, which are for brevity described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or with respect to other described embodiments as appropriate. A given feature described in the context of various embodiments should not be construed as essential to that embodiment, unless the particular embodiment is inoperable without that element.

[0136] It is the intention of the applicant that all publications, patents, and patent applications mentioned in this specification be incorporated herein by reference in their entirety to the same extent as if each individual publication, patent, and patent application was specifically and individually incorporated herein by reference. In addition, citation or identification of any reference in this application should not be construed as an admission that such reference is available as prior art to the present disclosure. Nor should it necessarily be construed as limiting, to the extent that section headings are used. In addition, the priority document of this application, if any, is incorporated herein by reference in its entirety.

Claims

1. 1. A power supply circuit for a non-thermal plasma generator, comprising: a driver circuit configurable to generate an AC power signal at an operating frequency of at least 500 kHz; an output stage circuit connected to receive the AC power signal from the driver circuit and to provide a feedback signal to the driver circuit for synchronizing the driver circuit to generate the AC power signal at the operating frequency, the output stage circuit having a plurality of transformers including at least a final transformer and an initial gain transformer; a plasma probe having a distal end having a plasma generation site and a proximal end coupled to the driver circuit via the output stage circuit, the distal end and the proximal end being interconnected by a transmission line having an intrinsic capacitance proportional to the length of the transmission line; at least one compensation capacitor selectable from a plurality of capacitances and / or adjustable; The selected and / or adjusted compensation capacitor of the at least one compensation capacitor may include: electrically in parallel with the intrinsic capacitance of the transmission line; and wherein the driver circuit has a capacitance that compensates for an LC network including the intrinsic capacitance and a secondary coil of the final transformer to resonate at the operating frequency when the driver circuit is implemented to generate the AC power signal. power circuit.

2. the final transformer includes the secondary coil and a primary coil, and the secondary coil of the final transformer is electrically connected to the plasma probe; the initial gain transformer includes a secondary coil and a primary coil, the secondary coil of the initial gain transformer is electrically connected to the plasma probe via the final transformer, and the primary coil of the initial gain transformer is electrically connected to the driver circuit; 2. The power supply circuit according to claim 1.

3. an inductance of the secondary coil of the final transformer is selected such that the LC network resonates at the operating frequency when a longest supported plasma probe having a longest supported transmission line length is connected without the selected and / or adjusted compensation capacitor; the plasma probe having a transmission line length that is less than the longest supported transmission line length; the sum of the capacitance of the selected and / or adjusted compensation capacitor and the intrinsic capacitance of the short transmission line is matched to the intrinsic capacitance of the longest supported transmission line; 3. The power supply circuit according to claim 1 or 2.

4. the selected and / or adjusted compensation capacitor is provided as a component of the plasma probe and is selected according to the selection of the plasma probe; The power supply circuit according to any one of claims 1 to 3.

5. a proximal connector of the plasma probe comprising the at least one compensation capacitor; The power supply circuit according to any one of claims 1 to 4.

6. the at least one compensation capacitor is provided together with the driver circuit, and the plasma probe is electrically connected to the at least one compensation capacitor when attached to the driver circuit via the output stage circuit. The power supply circuit according to any one of claims 1 to 3.

7. the at least one compensation capacitor includes a plurality of compensation capacitors, and the power supply circuit includes a controller that selects the selected and / or adjusted compensation capacitor from the plurality of compensation capacitors and connects it to the plasma probe.

7. The power supply circuit according to claim 6.

8. The controller includes a manually operated switch.

8. The power supply circuit according to claim 7.

9. The controller includes an electrically operated switch.

8. The power supply circuit according to claim 7.

10. The electrically operated switch is one of a plurality of multiplexed switches.

10. The power supply circuit according to claim 9.

11. the controller selecting and / or adjusting the selected and / or adjusted compensation capacitor in response to a user input command from a graphical user interface; 8. The power supply circuit according to claim 7.

12. further comprising an identifier detector; the controller selects and / or adjusts the selected and / or adjusted compensation capacitor in response to an identifier element associated with the plasma probe and providing an identifier sensed by the identifier detector, and a compensation capacitance associated with the identifier.

8. The power supply circuit according to claim 7.

13. the identifier includes a resistance value measured when the plasma probe is electrically connected to the driver circuit; 13. The power supply circuit of claim 12.

14. the identifier comprises a numeric value; 13. The power supply circuit of claim 12.

15. further comprising a frequency detector; the controller selecting the compensation capacitor based on an identified actual frequency of operation of the device and a difference between that frequency and the operating frequency of at least 500 kHz.

8. The power supply circuit according to claim 7.

16. providing a power supply configured to drive a high-capacitance plasma probe in cooperation with a secondary coil of a coupling transformer at a first frequency, the capacitance of the high-capacitance plasma probe including an intrinsic capacitance of a transmission line of the high-capacitance plasma probe; providing a low capacitance plasma probe having a transmission line with a specific capacitance lower than the specific capacitance of the transmission line of the high capacitance plasma probe; selecting a compensation capacitor based on a difference in capacitance between the high-capacitance plasma probe and the low-capacitance plasma probe; electrically connecting the compensation capacitor in parallel with the intrinsic capacitance of the low capacitance plasma probe; operating the low capacitance plasma probe at the first frequency; A method for generating plasma, comprising:

17. an RC network including the secondary coil and the transmission line of the low capacitance plasma probe, without the compensation capacitor, resonating at a second frequency higher than the first frequency; The method for generating plasma according to claim 16.

18. an RC compensation capacitor having a capacitance approximately equal to the difference in capacitance between the high capacitance plasma probe and the low capacitance plasma probe; The method for generating plasma according to claim 16 or 17.

19. the selecting includes selecting the compensation capacitor from a plurality of capacitors and / or adjusting the capacitance of the compensation capacitor. The plasma generating method according to any one of claims 16 to 18.

20. a set of at least two plasma probes, each comprising a distally located plasma generation site, a proximally located connector configured to connect to a plasma power source, and a transmission line interconnecting the connector and the plasma generation site; each of the plasma probes includes a compensation capacitor; the compensation capacitors have rated values that differ from each other by at least 10%; the difference between the capacitance values of the intrinsic capacitances of the transmission line is greater than the difference between the capacitance values of the sums of the intrinsic capacitances and the compensation capacitors; A set of at least two plasma probes.

21. The difference in capacitance value of the transmission line is reduced by at least two times the sum of the intrinsic capacitance and the compensation capacitor capacitance.

21. A set of at least two plasma probes according to claim 20.

22. The transmission lines differ in length from one another by at least 10 cm.

22. A set of at least two plasma probes according to claim 20 or 21.

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