Devices, systems and methods for reducing build-up of coagulum

Abstract

The present disclosure relates to devices, systems and methods for reducing build-up of coagulum in electrosurgical handpieces or applicators which reduces clogging and the need to clean the electrosurgical handpieces. An electrosurgical generator includes a power supply that supplies electrosurgical energy to an applicator via a radio frequency (RF) output stage; a flow controller that supplies a flow of gas to the applicator; and a controller coupled to the flow controller that adjusts a flow rate of gas to the applicator to a first flow rate during activation of the application and adjusts the flow rate to a second flow rate during de-activation for a predetermined period of time. The electrosurgical generator may include at least one sensor coupled to the controller that senses back pressure of the flow of gas to the applicator, where the controller may generate an alarm if the back pressure exceeds a predetermined setpoint.

Description

DEVICES, SYSTEMS AND METHODS FOR REDUCING BUILD-UP OF COAGULUMPRIORITYThis application claims priority to U.S. Provisional Patent Application Serial No. 63 / 672,432, filed July 17, 2024, entitled “DEVICES, SYSTEMS AND METHODS FOR REDUCING BUILD-UP OF COAGULUM”, the contents of which are hereby incorporated by reference in its entirety.BACKGROUND

[0001] Field.

[0002] The present disclosure relates generally to electrosurgery and electrosurgical systems and apparatuses, and more particularly, devices, systems and methods for reducing the build-up of coagulum in electrosurgical handpieces which reduces clogging and the need to clean the electrosurgical handpieces.

[0003] Description of the Related Art.

[0004] High frequency electrical energy has been widely used in surgery and is commonly referred to as electrosurgical energy. Tissue is cut and bodily fluids are coagulated using electrosurgical energy.

[0005] Electrosurgical instruments generally comprise "monopolar" devices or "bipolar" devices. Monopolar devices comprise an active electrode on the electrosurgical instrument with a return electrode attached to the patient. In monopolar electrosurgery, the electrosurgical energy flows through the active electrode on the instrument through the patient's body to the return electrode. Such monopolar devices are effective in surgical procedures where cutting and coagulation of tissue are required and where stray electrical currents do not pose a substantial risk to the patient.

[0006] Bipolar devices comprise an active electrode and a return electrode on the surgical instrument. In a bipolar electrosurgical device, electrosurgical energy flows through the active electrode to the tissue of a patient through a short distance through the tissue to the return electrode. The electrosurgical effects are substantially localized to a small area of tissue that is disposed between the two electrodes on the surgical instrument. Bipolar electrosurgical devices have been found to be useful with surgical procedures where stray electrical currents may pose a hazard to the patient or where other procedural concerns require close proximity of the active and return electrodes. Surgical operations involving bipolar electrosurgery often require methods and procedures that differ substantially from the methods and procedures involving monopolar electrosurgery.

[0007] Gas plasma is an ionized gas capable of conducting electrical energy. Plasmas are used in surgical devices to conduct electrosurgical energy to a patient. The plasma conducts the energy by providing a pathway of relatively low electrical resistance. The electrosurgical energy will follow through the plasma to cut, coagulate, desiccate, or fulgurate blood or tissue of the patient. There is no physical contact required between an electrode and the tissue treated.

[0008] Electrosurgical systems that do not incorporate a source of regulated gas can ionize the ambient air between the active electrode and the patient. The plasma that is thereby created will conduct the electrosurgical energy to the patient, although the plasma arc will typically appear more spatially dispersed compared with systems that have a regulated flow of ionizable gas.

[0009] Generators may be programmed to trigger fault codes (and stop activation) if the generator senses high back pressures from a handpiece during activation (e.g., sensesa high pressure in a line or tubing providing gas from the generator to the handpiece). Common causes for these faults during subdermal treatment are the following:1 . Coagulum build up in the handpiece tip. This tends to be more prevalent in clinical cases with higher patient bleeding rates.2. Using the handpiece in a tight tissue space which can temporarily pinch the handpiece tip, and / or using the handpiece in fibrous dense tissue.3. Doctors using their non-dominate hand to press down on the outside of tissue which can temporarily pinch the handpiece (i.e., when a tip or shaft of the handpiece is located in the subdermal space) and therefore block the exit ports of the handpiece tip.4. The handpiece cable (specifically the tubing in the cable) getting kinked from using the handpiece at an extreme angle.Points 2 to 4 above can be addressed by training and / or surgeon experience. Still there are device design improvements that can be made that would reduce the number of faults for doctors who are new to the device, and for experienced doctors that ends up with a challenging case (for example with a patient with higher bleeding rates in the subdermal space).SUMMARY

[0010] The present disclosure relates to devices, systems and methods for reducing the build-up of coagulum in electrosurgical handpieces which reduces clogging and the need to clean the electrosurgical handpieces.

[0011] According to one aspect of the present disclosure, an electrosurgical generator includes a power supply that supplies electrosurgical energy to an applicator via a radio frequency (RF) output stage; a flow controller that supplies a flow of gas to the applicator; and a controller coupled to the flow controller that adjusts a flow rate of gas to the applicator to a first flow rate during activation of the application and adjusts the flow rate to a second flow rate during de-activation for a first predetermined period of time.

[0012] In another aspect, the electrosurgical generator further includes at least one sensor coupled to the controller that senses back pressure of the flow of gas to the applicator.

[0013] In one aspect, if the controller determines that the sensed back pressure is greater than a predetermined setpoint, the controller generates an alert.

[0014] In another aspect, the electrosurgical generator further includes an alarm device coupled to the controller that receives the alert and generates an audible alarm.

[0015] In a further aspect, the electrosurgical generator further includes a display device coupled to the controller, wherein if the controller determines that the sensed back pressure is greater than a predetermined setpoint, the controller generates an alert on the display device.

[0016] In yet another aspect, the alert is displayed on the display device as a pressure gauge icon.

[0017] In still another aspect, the electrosurgical generator further includes a display device coupled to the controller, the controller generates an indication of back pressure as a pressure gauge icon on the display device.

[0018] In one aspect, the second flow rate is less than the first flow rate.

[0019] In another aspect, the second flow rate is approximately 0.5 liters per minute (l / min).

[0020] In a further aspect, the first predetermined period of time is at least 13.4 seconds.

[0021] In one aspect, if the applicator is re-activated during the first predetermined period of time, the controller adjusts the flow rate to the first flow rate.

[0022] In another aspect, upon activation, the controller adjusts the flow rate of gas to the applicator to a third flow rate for a second predetermined time period before adjusting the flow rate to the first flow rate, the third flow rate being greater than the first flow rate.

[0023] In a further aspect, the third flow rate is at least twice the flow rate of the first flow rate.

[0024] According to another aspect of the present disclosure, a method of an electrosurgical generator for generating plasma at an applicator coupled to the electrosurgical generator includes receiving a signal indicative of the applicator being activated; providing electrosurgical energy to the applicator; providing a flow rate of gas to the applicator at a first flow rate during activation; and adjusting the flow rate to a second flow rate during de-activation of the applicator for a first predetermined period of time, the second flow rate being less than the first flow rate.

[0025] In one aspect, the method further includes adjusting the flow rate of gas to the applicator to a third flow rate for a second predetermined time period before adjusting the flow rate to the first flow rate, the third flow rate being greater than the first flow rate.

[0026] In another aspect, the third flow rate is at least twice the flow rate of the first flow rate.

[0027] In a further aspect, if the applicator is re-activated during the first predetermined period of time, adjusting the flow rate to the first flow rate.

[0028] In yet another aspect, the method includes wherein upon de-activation, delaying adjustment to the second flow rate for a predetermined period of time.BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

[0030] FIG. 1 A is an illustration of an electrosurgical system in accordance with an embodiment of the present disclosure;

[0031] FIG. 1 B is a perspective view of an exemplary distal tip of an applicator or handpiece in accordance with an embodiment of the present disclosure;

[0032] FIG. 1 C is a side view of an exemplary distal tip of an applicator or handpiece in accordance with an embodiment of the present disclosure;

[0033] FIG. 2A is a front view of an electrosurgical generator of the electrosurgical system of FIG. 1 in accordance with an embodiment of the present disclosure;

[0034] FIG. 2B is a block diagram of an electrosurgical generator of the electrosurgical system of FIG. 1 in accordance with an embodiment of the present disclosure;

[0035] FIG. 3 is a flowchart illustrating a method for reducing the build-up of coagulum in electrosurgical handpieces in accordance with an embodiment of the present disclosure;

[0036] FIG. 4A is a graph illustrating idle gas flow being provided to a handpiece in accordance with an embodiment of the present disclosure;

[0037] FIG. 4B is a graph illustrating idle gas flow being provided to a handpiece in accordance with another embodiment of the present disclosure;

[0038] FIG. 5A is a graph illustrating back pressure over time for a relatively new handpiece (i.e., little or no clogging) in accordance with an embodiment of the present disclosure;

[0039] FIG. 5B is a graph illustrating back pressure over time for a relatively clogged handpiece in accordance with an embodiment of the present disclosure;

[0040] FIG. 6 is a graph illustrating a comparison of flow algorithms in accordance with an embodiment of the present disclosure;

[0041] FIG. 7 illustrates various states of a pressure gauge icon disposed on a display of an electrosurgical generator in accordance with an embodiment of the present disclosure;

[0042] FIG. 8A is a perspective view of an exemplary electrosurgical generator in accordance with an embodiment of the present disclosure;

[0043] FIG. 8B is a front view of an exemplary electrosurgical generator in accordance with an embodiment of the present disclosure; and

[0044] FIG. 80 is an exemplary screenshot of a display of an electrosurgical generator in accordance with an embodiment of the present disclosure.

[0045] It should be understood that the drawings are for purposes of illustrating the concepts of the disclosure and are not necessarily the only possible configuration for illustrating the disclosure.DETAILED DESCRIPTION

[0046] Preferred embodiments of the present disclosure will be described hereinbelow with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail. In the drawings and in the description which follow, the term “proximal”, as is traditional, will refer to the end of the device, e.g., instrument, apparatus, applicator, handpiece, forceps, etc., which is closer to the user, while the term “distal” will refer to the end which is further from the user. Herein, the phrase “coupled” is defined to mean directly connected to or indirectly connected with through one or more intermediate components. Such intermediate components may include both hardware and software-based components.

[0047] It will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative circuitry embodying the principles of the disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, state transition diagrams, pseudo-code, and the like represent various processes which may be substantially represented in computer readable media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

[0048] The present disclosure relates to devices, systems and methods for reducing the build-up of coagulum in electrosurgical handpieces which reduces clogging and the need to clean the electrosurgical handpieces.

[0049] Referring to FIG. 1A, an electrosurgical system 1 is shown in accordance with the present disclosure. System 1 includes an applicator or handpiece 10 and anelectrosurgical generator unit (ESU) 50. In some embodiments, system 1 further includes a gas supply 70.

[0050] Applicator 10 is configured to receive electrosurgical energy from ESU 50 via a cable 20. Applicator 10 is further configured to receive an inert gas from a gas source 70. In some embodiments, the inert gas is received from a gas supply 70 and provided from ESU 50 to applicator 10 via cable 20. It is to be appreciated that gas supply 70 may be internal to ESU 50 or external to ESU 50. In other embodiments, applicator 10 receives the inert gas directly from gas supply 70. Applicator 10 includes a handle housing 12 having at least one button 18 and a shaft 14 having a distal tip 16. When button 18 is pressed, electrosurgical energy is delivered to applicator 10 by ESU 50 and inert gas is delivered to applicator 10 by the gas source 70. The electrosurgical energy is used to energize an electrode disposed in the distal end 16 of the shaft 14. When the inert gas is passed over the energized electrode, a plasma is generated and emitted from tip 16 to patient tissue, which allows for conduction of the radio frequency (RF) energy from the electrode to the patient in the form of a precise plasma beam. In one embodiment, helium is used as the inert gas because helium can be converted to a plasma with very little energy, however, other inert gases, such as argon, are considered within the scope of the present disclosure. Additionally, mixtures of inert gases may be utilized to generate a plasma. Exemplary applicators are shown and described in commonly-owned U.S. Patent No. 9,060,765 and U.S. Patent AppL Publication No. 2022 / 0071684, the contents of which are incorporated by reference.

[0051] Referring to FIGS. 1 B and 1 C, an exemplary distal tip 16 of an electrosurgical applicator 10 is illustrated. The distal tip 16 includes at least one port 17A,17B disposedthrough a side wall of tip 16 and oriented in a radial direction traverse to axis A. Distal end 15 of tip 16 includes an exterior surface or wall 1 1 shaped as an elliptic paraboloid or an elliptical cone with a blunted or rounded tip 9 converging toward distal end 15, which enable tip 16 to glide through the subcutaneous tissue with minimal resistance. An electrode 7 is retained in the distal end 16 such that when electrosurgical energy and gas are applied to the distal tip 16 via shaft 14 plasma is emitted from ports 17A, 17B.

[0052] It is to be appreciated that, in some embodiments, applicator 10 may be configured to apply or deliver energy to patient tissue in ways or forms other than plasma. For example, applicator 10 may deliver RF energy to patient tissue via direct contact of the electrode to patient tissue. In some embodiments, the electrode may be retractable / extendable within shaft 14 to enable the electrode to be extended beyond the distal tip to directly contact patient tissue to deliver RF energy or retracted to deliver RF energy via plasma. In other embodiments, the electrode may be configured as a probe or heating element (e.g., heated by applying current received from ESU 50 to the heating element) and heat energy may be applied directly to patient tissue by the heat element.

[0053] Referring to FIG. 2A, a front view of ESU 50 is shown in accordance with an embodiment of the present disclosure. In one embodiment, the ESU 50 includes a high frequency electrosurgical generator 61 and gas flow controller 62 contained in a single housing 63. The ESU 50 includes a front panel face 19 which includes an input / output section 21 , e.g. a touchscreen, for entering commands / data into the ESU 50 and for displaying data. The front panel 19 may further include various level controls 22 with corresponding indicators 24. Additionally, the ESU 50 includes a receptacle section 26 which may include an On / Off switch 28, a return electrode receptacle 30, a monopolarfoot-switching receptacle 32, monopolar hand-switching receptacle 34 and a bipolar hand-switching receptacle 36. The gas flow controller 62 includes a gas receptacle portion 38 which may further include a Gas A input receptacle 40 and a Gas B input receptacle 42. The gas flow controller 62 may further include a user interface portion 44 including selector switch or input 46 and a display 48. The selector switch or input 46 enables selection of the type of gas being input, selection of a mixture of gases being input, a composition and / or percentages of a mixture of gases being input, a flow rate of a gas being applied to a handpiece or applicator, etc. It is to be appreciated that although FIG. 2A shows the high frequency electrosurgical generator 61 and gas flow controller 62 housed in a single housing 63, gas flow controller 62 may be provided as a separate, external device which interfaces with the ESU 50, via a wired and / or wireless interface. It is to be appreciated that although input / output section 21 , level controls 22, indicators 24, selector switch or input 36 and display 48 are shown as separate components, the functionality of each of these components may be consolidated as a single touchscreen disposed on a surface of the housing 63 of the ESU 50, the single touchscreen configured to receive various types of inputs and provide various types of outputs.

[0054] Referring to FIG. 2B, a block diagram of ESU 50 is shown in accordance with an embodiment of the present disclosure. ESU 50 includes controller or processor 51 , power supply 52, radio frequency (RF) output stage 54, I / O interface 56, alarm device 58, memory 60, flow controller 62, sensor 64, sensor 65 and a communication module 66. Controller 51 is configured to control power supply 52 to supply electrosurgical energy being output from RF output stage 54 via at least one conductor 53 extending through cable 20 to the applicator 10. It is to be appreciated that cable 20 may be coupled to ESU50 via monopolar hand-switching receptacle 34 or bipolar hand-switching receptacle 36. I / O interface 56 is configured to receive user input (e.g., via one or more buttons 22, 46, touchscreens 21 , etc., disposed on the housing of ESU 50) to be provided to the controller51 and output information (e.g., data to indicators 24, graphical user interfaces to touchscreen 21 , etc.) received from controller 51 . Audible alarm device 58 is controllable via controller 51 to alert an operator to various conditions or events. It is to be appreciated that the audible alarm device 58 may be a beeper, buzzer, speaker, etc. It is further to be appreciated that an alarm or alert may trigger the audible alarm device 58 to produce a sound while a visual indication is also displayed on the touchscreen 21 .

[0055] Flow controller 62 is configured for controlling the flow of gas received from supply 70 to the applicator 10. The flow controller 62 is coupled to the controller 51 and receives control signals from the controller 51 based on user input via I / O interface 56, selector switch or input 46 or based on an algorithm or software function stored in memory 60. Additionally, the flow controller 62 may include appropriate sensors to determine a type of gas being input to receptacles 40, 42. Furthermore, the flow controller 62 may use the inputted gases to create a mixture of gases to be provided to the applicator. Although in the embodiment shown in FIG. 2B, the flow controller 62 is disposed in the ESU 50, the flow controller 62 can be located external to the ESU 50 and disposed, for example, in a separate housing, in the applicator 10, etc.

[0056] Communication module 66 of ESU 50 is configured to communicate with other devices (e.g., client devices, servers, etc.) via a communication link (e.g., wired or wireless) to send and receive data and communications. Although in the embodiment shown in FIG. 2B, an operator is alerted to various conditions via an audible alarm device58 and / or touchscreen 21 , in other embodiments, controller 51 may use communication module 66 to send notifications to at least one other device via the communication link (e.g., wired or wireless), where the communications are associated with the various conditions or events. The communication module 66 may be a modem, network interface card (NIC), wireless transceiver, etc. The communication module 66 will perform its functionality by hardwired and / or wireless connectivity. The hardwire connection may include but is not limited to hard wire cabling e.g., parallel or serial cables, RS232, RS485, USB cable, Firewire (1394 connectivity) cables, Ethernet, and the appropriate communication port configuration disposed on a surface of housing 63. The wireless connection may operate under any of the various wireless protocols including but not limited to Bluetooth™ interconnectivity, infrared connectivity, radio transmission connectivity including computer digital signal broadcasting and reception commonly referred to as Wi-Fi or 802.11.X (where x denotes the type of transmission), satellite transmission or any other type of communication protocols, communication architecture or systems currently existing or to be developed for wirelessly transmitting data including spread spectrum 900 MHz, or other frequencies, Zigbee, and / or any mesh enabled wireless communication.

[0057] In one embodiment, sensor 64 of ESU 50 is coupled to the output of RF output stage 54. Sensor 64 is configured to sample the voltage and / or current (or any other electrical properties) of the output of stage 54 and provide the sample voltage and / or current to controller 51 . Controller 51 may use the information to determine one or more properties associated with the power provided by ESU 50 to applicator 10. In one embodiment, sensor 64 may include at least one voltage sensor for sensing outputvoltage and at least one current sensor for sensing output current. Optionally, sensor 64 may include at least one analog-to-digital converter for converting the sensed signal to a digital signal to be input to controller 51 ; or alternatively, at least one analog-to-digital converter may be provided on controller 51 .

[0058] In one embodiment, sensor 65 of ESU 50 is coupled to the output of flow controller 62. Sensor 65 is configured to sample the back pressure of an output 55 of flow controller 62 and provide the sampled back pressure to controller 51. Optionally, sensor 65 may include at least one analog-to-digital converter for converting the sensed signal to a digital signal to be input to controller 51 ; or alternatively, at least one analog-to-digital converter may be provided on controller 51 . Controller 51 may use the information to determine if coagulum is being built up on a distal end of the applicator 10 or if the distal end 16 of the applicator is clogged, as will be described below.

[0059] It is to be appreciated that the functions of the ESU 50 shown in FIGS. 1 and 2A- B may be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. In one embodiment, some or all of the functions of controller 51 may be performed by at least one processor, such as a computer or an electronic data processor, digital signal processor or embedded micro-controller, field programmable gate array (FPGA), in accordance with code, such as computer program code, software, firmware, register transfer logic and / or integrated circuits that are coded to perform such functions, unless indicated otherwise. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” or “controller” should notbe construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, read only memory (ROM) for storing software and / or firmware, random access memory (RAM), and nonvolatile storage.

[0060] Referring to FIG. 3, a method 200 for determining if coagulum is being built up on a distal end of the applicator 10 or if the distal end of the applicator is clogged is shown in accordance with an embodiment of the present disclosure. A clogged distal end 16 of an applicator or handpiece typically results in a weaker treatment and therefore, a longer treatment.

[0061] In step 201 , a connector of handpiece is coupled to the appropriate port of ESU 50. The console will detect when an appropriate handpiece is connected (e.g., by retrieving a 1 -wire data table disposed in a memory of the connector). An idle gas flow mode enable is sent to the gas flow controller 62 (or controller 51 ), which will enable an idle flow algorithm. It is to be appreciated that the idle flow algorithm may be employed with handpieces that have a higher propensity to allow blood / debris to enter the tip and to clog, e.g., handpieces that have relatively small radial exit ports (as shown in FIGS. 1 B and 1 C), as compared to other handpiece that utilizes a front firing tip instead. If a different handpiece is connected that does not have a propensity to clog (as determined by a stored 1 -wire data table disposed in the memory of the connector), the idle flow mode will not be enabled and the ESU 50 will employ a gas burst algorithm, as will be described below.

[0062] In step 202, the handpiece or applicator 10 is activated, e.g., to provide plasma via button 18 or a footswitch. In step 204, electrosurgical energy and gas is provided to thehandpiece 10 to create plasma at a distal tip 16 of the handpiece 10 and apply the generated plasma to tissue. It is to be appreciated that the flow rate of gas to the handpiece 10 may be selected and adjusted, e.g., via the touchscreen 21 of the ESU 50, user interface 44 or may be adjusted based on a particular procedure selected by a user via the touchscreen.

[0063] In step 206, sensor 65 senses the back pressure of the tube 55 supplying gas to the handpiece 10. In step 208, the controller 51 of ESU 50 determines if the sensed back pressure is greater than an adjustable, predetermined setpoint. If the back pressure is greater than the setpoint in step 208, the controller 51 deactivates the handpiece 10 in step 210 and also generates an alarm, in step 212. It is to be appreciated that the alarm may be a beep, sound, spoken voice, etc. via alarm device 58 and / or a visual indication via touchscreen 21 . If the back pressure is not greater than the setpoint in step 208, the controller 51 will monitor the handpiece to determine if the handpiece is deactivated, e.g., releasing button 18 to not apply plasma , in step 214. If the handpiece is still active in step 214, the controller 51 will continue to monitor the back pressure via sensor 65. If the handpiece is de-activated in step 214, the controller 51 will control the flow controller 62 to provide an idle flow gas rate to the handpiece 10 for an adjustable predetermined period of time, in step 216. In one embodiment, after activation is stopped, the gas flow shall continue flowing, at a predetermined flow rate and a predetermined flow period (e.g., a flow rate of 0.5 l / min for 13.4 seconds) or until the handpiece is activated again.

[0064] It is to be appreciated that the flow rate and period of time may be adjustable. Additionally, the flow rate and period of time may be selected based on at least one factor, such as handpiece type, selected procedure, etc. In one embodiment, a range for the flowrate may be between 0.1 l / min to 1 .0 l / min. In another embodiment, the range for the flow rate is 0.3 l / min to 0.5 l / min. It is further to be appreciated that the at the lower end of the range, the idle flow rate will not be effective for preventing clogging, and at the upper end of the range, the generator will trigger gas flow and / or gas pressure errors when the handpiece is pushed forward through tissue during the idle flow period.

[0065] As for the idle flow period, on the lower end, the time of the idle flow period has to be long enough so that the flow doesn’t stop while the handpiece is pushed forward through tissue (i.e., non-activated) when the handpiece is used with retrograde only activation (i.e., activated when pulled back, but not when pushed forward). For example, the time it takes for a user to push the handpiece forward before the next activation is around 2-3 seconds. The idle flow time period also has to be longer than the pause that the user might make (e.g., for reorienting the handpiece, or determine the position of the handpiece tip) during retrograde and antegrade activation (activating on both forward and backward motion), for example, 3-5 seconds. On the upper end, there is no specific time restriction. Theoretically, the idle flow can continue for as long as the handpiece is connected. The problem here would however be that the user could deplete the entire helium tank (e.g., gas source 70) since the handpiece is continuously emitting helium. The idle flow may be a minimum of 5 seconds (and 10 seconds for added margin), and no longer than 30 seconds. If the doctor or user hasn’t reactivated within 30 seconds, then the procedure is most likely done, or the doctor has set the handpiece aside temporarily. Therefore, in one embodiment, the idle flow period is ideally 10-20 seconds. In another embodiment, the idle flow period may be in a range of 5 to 30 seconds but with lower margin (on the lower end) or higher helium gas consumption (on the upper end).

[0066] The providing of the idle flow rate for a predetermined period of time significantly reduces the clogging of the distal tip because it is much harder for blood / tissue to enter the tip of the handpiece while helium is flowing when the handpiece is deactivated, e.g., to enter ports 17A, 17B of distal tip 16. Sometimes surgeons / users stop activating while the handpiece is under the tissue. It is during this time that blood / tissue enters the warm / hot tip and can coagulate the blood / tissue inside the tip / shaft causing a clog. The idle flow for approximately 13.4 seconds ensures that helium continues to flow while the handpiece is not being activated under the tissue and prevents blood / tissue from getting down into the tip / shaft. It is unlikely that the user will not be activating the handpiece while under the skin for longer than 13.4 seconds. Even if the user did leave the handpiece while under the skin for longer than 13.4 seconds and idle flow stopped, the tip will have cooled down after this period of time reducing the chance of the blood / tissue coagulating and causing a blockage.

[0067] In step 218, the controller 51 determines if the handpiece 10 is activated again during the predetermined time period, and if the handpiece was activated, the controller 51 reverts to step 206 to continue to monitor the back pressure at sensor 65. In step 218, if the controller 51 determines the handpiece was not re-activated, the procedure is terminated and gas flow is ceased after the predetermined idle flow time has expired, in step 220.

[0068] Referring to FIG. 4A, a graph illustrating how the idle flow works is provided. Note that the y-axis represents gas flow in liters per minute (l / min) and the x-axis represents time. FIG. 4A shows the idle flow algorithm without gas burst, where (a) is the gas flow level of the idle flow, (b) is the gas flow level set, for example, by the user on a screen ofthe ESU 50, (c) is the time of handpiece activation, (d) is the timepoint of handpiece deactivation, and (e) is the timepoint of idle flow stopping. This means that the idle flow will be flowing for a time of t = e - d. During activation, the gas flow increases to the selected gas flow (i.e., by the user), in this example the flow is 1 .5 l / min. The gas flow stays at 1 .5 l / min as long as the handpiece stays activated. When the handpiece is no longer activated (e.g., time d), the gas flow would drop down to zero, if the idle flow algorithm was not enabled. In the idle flow algorithm, the gas flow instead drops down to a lower-level gas flow or second predetermined flow rate (in this example 0.5 l / min). In one embodiment, the generator implements 13.4 seconds of idle flow, however, the idle flow time could be longer or shorter. The idle flow level could also be higher or lower than 0.5 l / min. It is to be appreciated that the idle flow rate and / or the period of time of idle flow may be adjustable.

[0069] FIG. 4B shows an alternative idle flow algorithm where there is a time delay after deactivation before the flow drops down to the idle flow level. In this embodiment, the set flow rate for a particular procedure continues for a set time after deactivation before dropping down to idle flow level (i.e., from time d until time e). In FIG. 4B, (a) is the gas flow level of the idle flow, (b) is the gas flow level set, for example, by the user on the screen of the ESU 50, (c) is the time of handpiece activation, (d) is the timepoint of handpiece de-activation, (e) is the timepoint of the gas flow dropping from the flow level set by the user to the idle flow level, and (f) is the idle flow stopping. This means that the setpoint flow will be active for t = e - d after deactivation, and the idle flow will be flowing for t = f - e.

[0070] As mentioned above, a gas burst algorithm may be employed by the ESU 50. In general, the gas burst algorithm includes a burst of helium gas of 3 l / min on initial activation regardless of the helium flow set point on the generator. The gas burst is employed to reduce the amount of time it takes for helium to reach the tip of the handpiece and to ensure helium is present at the tip prior to the initiation of RF energy. When used in subdermal treatment applications removal of the gas burst is beneficial, as will now be described.

[0071] FIG. 5A shows the back pressure during activation for a handpiece using the gas burst algorithm and an algorithm without gas burst. In this example, the user has selected 1 .5 l / min as the gas flow setpoint. During activation, the two different algorithms behave differently in the following way:• Gas burst algorithm 250 - uses a “gas burst” of, for example, 3 l / min for the first 600 milliseconds of activation. The time period for the gas burst can however range from 400 msec to 800 msec depending on the gas burst flow level used. Additionally, it is to be appreciated that the flow rate and period of time may be adjustable and / or selected based on at least one factor, such as handpiece type, selected procedure, etc.. This creates an initial “pressure spike” or “pressure overshoot” 252 before the pressure drops down to a level 254 that is representative of a flow of 1 .5 l / min.• Algorithm with no gas burst 256 - In the algorithm with no gas burst, the gas flow instead goes directly to the setpoint selected by the user. For a setpoint of 1 .5 l / min, there is no pressure overshoot (for example, spike 252 as shown in Fig 5A). A line 258 for what the pressure curve would look like if the set flow was 3 l / min is also provided (i.e., setpoint or level for a procedure is equal to the gas burst level). If the setpoint is set to 3 l / min, the initial pressure is equivalent to the “pressure spike” seen with the gas burst algorithm.FIG. 5A represents a new or only somewhat used handpiece, i.e., little or no clogging at the distal tip 16. For a new handpiece, there is plenty of margin up to the back pressure level where a gas fault would trigger (dashed line 260 labeled “Gas Fault” in FIG. 5A). The dotted line 250 shows the back pressure during the initial gas burst using the gas burst algorithm. Because the initial gas burst uses a gas flow of 3.0 l / min, it will generate a back pressure overshoot before decreasing back down to the back pressure representative of a 1.5 l / min gas flow. The solid line 254 shows the back pressure generated from the algorithm without a gas burst. This does not generate a back pressure overshoot. Instead, the back pressure increases directly to the level which represents 1 .5 l / min gas flow. The dashed line 260 in this graph represents the trigger level for a gas fault. Since this is a new or slightly clogged handpiece, neither of the two algorithms will trigger a gas fault (i.e., there is still some margin of pressure before a gas fault is triggered).

[0072] As the handpiece gets more and more clogged, the baseline pressure of the handpiece, however increases. This is shown in FIG. 5B. Since the back pressure baseline has now increased, the gas burst algorithm 262 will trigger gas faults (because of the pressure overshoot). At this point, the “pressure overshoot” 264 from the gas burst becomes a problem, i.e., the pressure overshoot increases above the “Gas Fault” trigger 266. The algorithm with no gas burst 268 does not trigger gas faults because there is no “pressure overshoot”.

[0073] It is to be understood that the above-described two features or algorithms may be implemented separately, or in any combination. For example, the controller 51 of EUS 50 may employ at least the following combinations: 1 .) using the gas burst feature with noidle flow; 2.) using the gas burst feature with idle flow; 3.) no gas burst and no idle flow; and 4.) using the idle flow feature with no gas burst.

[0074] FIG. 6 illustrates a graph showing how the idle flow and removed gas burst work together to reduce the number of flow faults. The dotted line 270 shows the back pressure of a handpiece throughout a (simulated) clinical case using the gas burst with no idle flow algorithm. The solid line 272 shows the back pressure for a handpiece using the idle flow with no gas burst algorithm over the same time frame reference as line 270. For both handpieces, there is an initial time period (a) where the back pressure is low. There is then a second time period (b) where the back pressure starts to increase. Finally, the handpieces end up in a semi-clogged stable state where the back pressure increases slower during time period (c). The main benefit of the idle flow is that it delays the time it takes for the back pressure to start to increase (the difference between (b) for dotted line 270 (e.g., approximately time t1 ) versus (b) for solid line 272 (e.g., approximately time t2)). This difference can be significant, with the idle flow with no gas burst algorithm delaying the onset of time period (b) (e.g., approximately time t2) with several times what it takes for a handpiece using the gas burst with no idle flow algorithm to reach onset of time period (b). When the handpieces reach time period (c), the removal of the gas burst is the main feature of the idle flow with no gas burst algorithm that will prevent gas faults. At this point, the back pressure baseline has increased to the level that the gas burst with no idle flow algorithm, will create the situation shown in FIG. 5B, i.e., the gas burst will increase the back pressure to the level that gas faults are triggered. The benefit of the idle flow with no gas burst algorithm is also explained in FIG. 5B. Because the idle flow with no gas burst algorithm does not generate a pressure overshoot, and since the slopeof pressure increase is lower during time period (c), the handpiece using the idle flow with no gas burst algorithm can be used much longer before creating any gas flow faults during time period (c) compared to handpieces using the gas burst with no idle flow algorithm.

[0075] The above-described four combinations may be summarized as follows:

[0076] 1 .) using the gas burst feature with no idle flow, i.e., the dotted curve 270 in FIG. 6, will have the problem highlighted by the dotted curve 262 in FIG. 5B (when it reaches part (c) of the curve);

[0077] 2.) using gas burst with idle flow, i.e., the solid curve 272 in FIG. 6 that will still have the problem highlighted by the dotted curve 262 in FIG. 5B (when it reaches part (c) of the curve), in other words, it will still have the problem in part c of the curve, but the idle flow will delay the onset of the pressure increase (b);

[0078] 3.) not using gas burst and with no idle flow, i.e., the dotted curve 270 in FIG. 6, will however not have the problem highlighted by the dotted curve 262 in FIG. 5B (when it reaches part (c) of the curve in FIG. 6), instead it will follow the solid curve 268 in FIG. 5B and go directly to the gas flow setting without pressure overshoot; and

[0079] 4.) not using gas burst and with idle flow will delay onset of the pressure increase (b) in FIG. 6, and will be helpful during part (c) of the curve 272 in FIG. 6, which is the best case scenario, i.e., the combination of using an idle flow with removal of the gas burst is the optimum algorithm for preventing clogging. This is the solid curve 272 in FIG. 6 and will also not have the problem highlighted by the dotted curve 262 in FIG. 5B (when it reaches part (c) of the curve in FIG. 6). Instead, it will follow the solid curve 268 in FIG. 5B and go directly to the gas flow setting without pressure overshoot.

[0080] During the method 200, the ESU will provide a visual indication to the user of the backpressure status and alarms. In one embodiment, the touchscreen of ESU may display an icon to show backpressure status, e.g., a pressure gauge icon as shown in FIG. 7. The pressure gauge icon has 5 states:State 1 (301 ): Disabled state (grayed graphics) - the Pressure Gauge icon is in disabled state when no valid handpiece is recognized.State 2 (302): 1 filled green bar - valid handpiece is recognized, and the output pressure is below 10 kPa ± 5 kPa.State 3 (303): 2 filled green bars - valid handpiece is recognized, and the output pressure is above 10 kPa ± 5 kPa and below 20 kPa ± 5 kPa.State 4 (304): 3 filled yellow bars - valid handpiece is recognized, and the output pressure is above 20 kPa ± 5 kPa.State 5 (305): 4 filled orange bars - valid handpiece is recognized, and output pressure or flow fault is present.Referring to FIGS. 8A and 8B, an exemplary ESU 350 is illustrated. It is to be appreciated that ESU 350 functions similar to ESU 50 as described in relation to FIGS. 2A and 2B. ESU 350 includes a display 321 , e.g., a touchscreen. In one embodiment, the display 323 displays pressure gauge icon 323 on a portion of the display. It is to be appreciated that display 321 may display any of the several states of pressure gauge icon as shown in FIG. 7. For example, FIG. 8A and 8B illustrate pressure gauge icon in state 5. FIG. 8C illustrates an exemplary screen shot of display 312 where pressure gauge icon 323 is illustrated in state 2.

[0081] Providing the pressure gauge icon allows for faster reset time after a backpressure fault since the controller 51 of ESU 50 does not have to redraw what is displayed on the touchscreen 21. It also removes faults that are triggered by the user activating the handpiece again when a backpressure fault is still displayed on the screen. Additionally,the pressure gauge icon is very useful in determining the status of the clogging of the handpiece and the efficacy of cleaning.

[0082] It is important for users to be able to reactivate quickly after a backpressure fault. By changing to the pressure icon instead of displaying backpressure faults on the screen, the recovery time before the users can reactivate can be reduced from 825 msec to 410 msec. This improves the speed of subsequent activations.

[0083] Sound volume for the backpressure faults may be adjustable. In one embodiment, the sound volume for each state of the pressure gauge icon may be individually adjustable. For example, as the pressure gauge icon transitions from one state to another, the sound volume may be adjusted to increase at each state transition to alert the user that the distal tip of the handpiece is becoming more clogged.

[0084] It is to be appreciated that the various features shown and described are interchangeable, that is a feature shown in one embodiment may be incorporated into another embodiment.

[0085] While the disclosure has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

[0086] Furthermore, although the foregoing text sets forth a detailed description of numerous embodiments, it should be understood that the legal scope of the invention is defined by the words of the claims set forth at the end of this patent. The detailed description is to be construed as exemplary only and does not describe every possible embodiment, as describing every possible embodiment would be impractical, if notimpossible. One could implement numerous alternate embodiments, using either current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.

[0087] It should also be understood that, unless a term is expressly defined in this patent using the sentence “As used herein, the term ‘ ’ is hereby defined to mean...” or a similar sentence, there is no intent to limit the meaning of that term, either expressly or by implication, beyond its plain or ordinary meaning, and such term should not be interpreted to be limited in scope based on any statement made in any section of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, that is done for sake of clarity only so as to not confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning. Finally, unless a claim element is defined by reciting the word “means” and a function without the recital of any structure, it is not intended that the scope of any claim element be interpreted based on the application of 35 U.S.C. § 112, sixth paragraph.

Claims

WHAT IS CLAIMED IS:1 . An electrosurgical generator comprising: a power supply that supplies electrosurgical energy to an applicator; a flow controller that supplies a flow of gas to the applicator; and a controller coupled to the flow controller that adjusts a flow rate of gas to the applicator to a first flow rate during activation of the application and adjusts the flow rate to a second flow rate during de-activation for a first predetermined period of time.

2. The electrosurgical generator of claim 1 , further comprising at least one sensor coupled to the controller that senses back pressure of the flow of gas to the applicator.

3. The electrosurgical generator of claim 2, wherein if the controller determines that the sensed back pressure is greater than a predetermined setpoint, the controller generates an alert.

4. The electrosurgical generator of claim 3, further comprising an alarm device coupled to the controller that receives the alert and generates an audible alarm.

5. The electrosurgical generator of claim 2, further comprising a display device coupled to the controller, wherein if the controller determines that the sensed back pressure is greater than a predetermined setpoint, the controller generates an alert on the display device.

6. The electrosurgical generator of claim 5, wherein the alert is displayed on the display device as a pressure gauge icon.

7. The electrosurgical generator of claim 2, further comprising a display device coupled to the controller, the controller generates an indication of back pressure as a pressure gauge icon on the display device.

8. The electrosurgical generator of claim 1 , wherein the second flow rate is less than the first flow rate.

9. The electrosurgical generator of claim 8, wherein the second flow rate is approximately 0.5 liters per minute (l / min).

10. The electrosurgical generator of claim 9, wherein the first predetermined period of time is at least 13.4 seconds.1 1. The electrosurgical generator of claim 10, wherein if the applicator is reactivated during the first predetermined period of time, the controller adjusts the flow rate to the first flow rate.

12. The electrosurgical generator of claim 8, wherein, upon activation, the controller adjusts the flow rate of gas to the applicator to a third flow rate for a secondpredetermined time period before adjusting the flow rate to the first flow rate, the third flow rate being greater than the first flow rate.

13. The electrosurgical generator of claim 12, wherein the third flow rate is at least twice the flow rate of the first flow rate.

14. The electrosurgical generator of claim 1 , wherein, upon deactivation, the controller delays adjustment to the second flow rate for a second predetermined period of time.

15. A method of an electrosurgical generator for generating plasma at an applicator coupled to the electrosurgical generator comprising: receiving a signal indicative of the applicator being activated; providing electrosurgical energy to the applicator; providing a flow rate of gas to the applicator at a first flow rate during activation; and adjusting the flow rate to a second flow rate during de-activation of the applicator for a first predetermined period of time, the second flow rate being less than the first flow rate.

16. The method of claim 15, further comprising adjusting the flow rate of gas to the applicator to a third flow rate for a second predetermined time period before adjusting the flow rate to the first flow rate, the third flow rate being greater than the first flow rate.

17. The method of claim 16, wherein the third flow rate is at least twice the flow rate of the first flow rate.

18. The method of claim 15, wherein, if the applicator is re-activated during the first predetermined period of time, adjusting the flow rate to the first flow rate.

19. The method of claim 18, further comprising: sensing a back pressure of the provided gas; and displaying an indication of the back pressure on a display of the electrosurgical generator.

20. The method of claim 18, further comprising: sensing a back pressure of the provided gas; and generating an alert if the back pressure is greater than a predetermined setpoint.

21. The method of claim 15, wherein upon de-activation, delaying adjustment to the second flow rate for a second predetermined period of time.

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