Systems and methods for tissue adhesion control

Abstract

Electrosurgical generator for treating body tissue, comprising (a) a high-frequency (HF) generator providing electrical energy to a surgical instrument, said electrical energy being an HF alternating current (AC) voltage; (b) a direct current (DC) voltage source overlaying a DC voltage on the HF generator output; (c) the DC voltage source is configured to provide a voltage level in the range of 0 to 20 volts and a current level in the range of 0 to 200 milliamperes; (d) a control unit configured to modulate the DC voltage based on a desired tissue effect The modulation includes controlling switching the DC voltage between ON and OFF state. Thereby a well-controlled electroadhesion effect can be achieved or terminated. Accordingly, a controlled unsticking of tissue to the instrument as well as an intended sticking can be performed, both improving the surgical behavior of the generator and expanding its utility. The invention further relates to a method and system.

Description

[0001] SYSTEMS AND METHODS FOR TISSUE ADHESION CONTROL

[0002] The present appl ication generally relates to systems and methods for tissue adhesion control , and more particularly to techniques for managing tissue adhesion during medical procedures . Related domains include diagnosis , surgery, identi fication, filters implantable into blood vessels , prostheses , devices providing patency to , or preventing collapsing of , tubular structures of the body, e . g . stents , orthopaedic, nursing or contraceptive devices , fomentation, treatment or protection of eyes or ears , bandages , dressings or absorbent pads , first- aid kits and healthcare informatics , i . e . information and communication technology [ ict ] specially adapted for the handling or processing of medical or healthcare data .

[0003] BACKGROUND ART

[0004] The patent document number US-20190015147 discloses unintended current flow or plasma discharge has been observed in known illuminated electrosurgical devices having a metallic tubular heat sink surrounding a conductive electrode and an illumination element , and having a distal outer edge that abuts against the light emitting element . An insulating, shielding or other isolating element that prevents or discourages unintended plasma formation between the distal outer edge and nearby patient tissue can reduce the potential for tissue damage to a patient or inj ury to a surgeon .

[0005] This approach presents limitations

[0006] PROBLEM STATEMENT

[0007] This application addresses the problem of unintended tissue sticking during electrosurgical procedures . The application provides solutions for controlling tissue adhesion. According to the invention, a positive control for adhesion ("sticking") of tissue to an instrument / electrode and releasing thereof ( "un-sticking" ) is achieved.

[0008] SUMMARY

[0009] The solution according to the invention resides in the independent claims. Preferable embodiments are the subject matter of the dependent claims.

[0010] Embodiments of the invention are associated with various advantages and / or technical effects. There is disclosed an elec- trosurgical generator for treating body tissue, comprising: a. a high-frequency (HF) generator configured to output an alternating current (AC) voltage in the kilohertz range for cutting and coagulating tissue; b. a direct current (DC) voltage source overlaying a DC voltage on the HF generator output to create or release an electroadhesion effect; c. wherein the DC voltage source is configured to provide a voltage level in the range of 0 to 20 volts and a current level in the range of 0 to milliamperes; d. a control unit configured to modulate the DC voltage based on a desired tissue effect, wherein the modulation includes controlling switching the DC voltage between an on state, in which the DC voltage is applied, and an off state, in which the DC voltage is not applied.

[0011] The provision of a high-frequency generator capable of out- putting an alternating current in the kilohertz range for cutting and coagulating tissue offers precise control over surgi- cal incisions and hemostasis , leading to reduced blood loss and improved surgical outcomes . Particularly, coagulation also comprises sealing of vessels , like blood vessels , which is of special importance .

[0012] The overlaying of a direct current ( DC ) voltage on the HF generator output creates an electroadhesion ef fect on tissue , which provides the advantage of preventing or loosening ( i . e . releasing) tissue sticking during electrosurgical procedures . Generally, the providing of a direct current voltage on the high- frequency generator output to create an electroadhesion ef fect enhances the versatility of the device , allowing for improved handling of tissues and potentially reducing the need for mechanical clamps or sutures . Further, tissue which is bonded by electroadhesion may be released by controlling DC voltage , often but not necessarily by reversing the DC voltage or by switching of f the DC voltage . Thereby electroadhesion can be released in a controlled manner, regardless whether the electroadhesion or sticking of the tissue is unintended, or it is sticking due to application of HF energy for or whether sticking is controlled by application of DC voltage . It is worth to note that sticking can happen due to electroadhesion as well as due to thermal ef fects , in particular under high temperature conditions . As the invention has reali zed, either kind of sticking may be released by controlling DC voltage as claimed .

[0013] The DC voltage i s a low voltage , in particular an "Extra Low Voltage (ELV) " which is safe in terms of avoiding electrical shock according to relevant standards of the competent bodies , in particular of the International Electrotechnical Commission ( IEC ) and its EN 61140 standard . Preferably, the DC voltage is at maximum hal f of the allowed voltage limit , further preferably the DC voltage is further limited to the even lower lim- its as required by regulations for toys , according to EU Directive 2009 / 48 . It may thus possible to extend the upper voltage limit to 24 Volt DC ( as opposed to 20 Volt now required by the independent claims ) without leaving the scope of the invention .

[0014] The ability of the control unit to modulate the direct current voltage based on the desired tissue ef fect , including controlling switching the DC voltage between an on state , in which the DC voltage i s applied, and an of f state , in which the DC voltage is not applied, provides a means to fine-tune the electrosurgical procedure , thereby minimi zing unintended tissue adhesion and facilitating easier manipulation of tissues during surgery .

[0015] The DC voltage source being switchable between an on state and an of f state provides the advantage of flexibility in applying the DC voltage as needed .

[0016] Such a switching of the DC source has further the advantage of enabling the surgeon to selectively apply the electroadhesion ef fect , thereby providing greater control over tissue handling and reducing the risk of tissue damage when the DC voltage is not required .

[0017] It is to be noted that the control unit may be reali zed as a dedicated DC control unit or by a section of a main control unit of the electrosurgical generator, or a combination thereof .

[0018] The providing and modulating of DC voltage thus improves electrosurgical generator and creates the advantage of improved tissue cutting and coagulation capabilities due to the combination of DC output with high- frequency (HF) generator out- putting an alternating current (AC ) voltage in the kilohertz range .

[0019] The term HF means high frequency and encompasses frequencies in the radio frequency range , termed RF, ( typically 200 kHz to 4 , 000 kHz ) and but may also encompass frequencies in the ultrasound frequency range ( typically 20 kHz to 200 kHz ) .

[0020] The control unit is further enabled to control the polarity of the DC voltage to prevent or loosen unintended tissue sticking during electrosurgical procedures .

[0021] This allows for preventing or loosening of tissue sticking during electrosurgical procedures . This applies in either case , whether it is unintended tissue sticking, sticking due to application o f HF energy or whether sticking is controlled by application o f DC voltage . The ability to modulate the DC voltage based on a desired tissue ef fect provides the advantage of enhanced controllability during electrosurgical procedures .

[0022] Preferably, the electrosurgical generator further comprises a user interface which is configured to allow the user to select between a non-sticking mode and a sticking mode of operation, provides the advantage of customi zation and adaptability to di f ferent surgical requirements .

[0023] The on / of f functionality of the DC voltage source has a further advantage by only consuming power when controlling of the electroadhesion ef fect is desired .

[0024] Advantageously, the control unit is configured such that modulation comprises controlling DC voltage or DC current or a combination thereof . This allows for a well measured supply of DC to the instrument . Preferably, the control unit of the generator is further configured for appl ication of the DC voltage intermittently alongside the HF mode . Moreover, the control unit is preferably configured to control duration of the application of the DC voltage and / or the DC energy to be supplied to the tissue . The control unit further preferably configured to control repetition of such application of DC voltage and DC energy, respectively . Further preferably, the control unit is enabled to control shape and / or duration of the DC voltage and energy supplied, e . g . full ON / OFF ( square-like ) , increasing ON and decreasing OFF ( triangle-like ) , increasing ON and sudden OFF ( sawtooth) or sudden ON and decreasing OFF ( sawtooth I I ) , etc .

[0025] The intermittent application of direct current voltage alongside the HF mode allows for a dynamic response to surgical conditions , enabling the surgeon to apply the electroadhesion ef fect in a targeted manner . The intermittent application can reduce thermal buildup in tissues , potentially decreasing the risk of thermal inj ury and improving patient safety during electrosurgical procedures .

[0026] The controlling of the polarity preferably comprises reversing the polarity of the DC voltage . By reversing the polarity it can be controlled when the DC voltage will be reversed such that sticked tis sue can be loosened or said loosening stops and / or sticking of tissue will be ef fected or released . Reversing of the polarity thus allows a determination of the begin and end of the sticking and / or loosening of said tissue , resp . . In other words , the control unit is preferably configured such as to provide suf ficient DC energy to release ("unstick" ) sticking tissue , in particular by reversing polarity (with respect to the DC voltage that had established the electroadhesion) , regardless whether the sticking occurred due to an electroadhesion bonding or due to thermal ef fects . Advantageously, the DC voltage is a low voltage up to 20 Volt , preferably up to 10 Volt and in particular at least 5 Volt , and / or for DC current in the range up to 200 mA, preferably up to 80 mA and in particular at least 2 mA. These values are within patient safe speci fications and further ensure a reliable and well controlled sticking and un-sticking ef fect to tissue . As already stated, it is beneficial to have a polarity reversal capabil ity .

[0027] Preferably, the electrode is comprised of a material which is conductive or has a conductive coating and features a positive Standard Electrode Potential (E° ) . Examples for such materials are non-metals e . g . carbon, graphite or some metals like gold, silver, platin, copper . More preferably, the material is also biocompatible , e . g . gold .

[0028] In a preferred embodiment , the control unit of the electrosurgical generator further comprises at least one of a microcontroller (pC ) , a central processing unit ( CPU) , a digital signal processor ( DSP ) , an application speci fic integrated circuit (AS IC ) , and / or a field-programmable gate array ( FPGA) . The inclusion of advanced control units such as a microcontroller, central processing unit , or field-programmable gate array provides the generator with the computational power to execute complex algorithms for real-time modulation of the electrosurgical output , enhancing the precision and responsiveness of the device . Moreover, the use of these sophisticated control units allows for future updates and refinements to the device ' s software , ensuring that the generator can adapt to new surgical techniques and standards .

[0029] The user interface that allows selection between non-sticking and sticking modes of operation provides the surgeon with a simple and intuitive means to tailor the electrosurgical gen- erator ' s performance to the speci fic requirements of the procedure , improving surgical ef ficiency and outcomes .

[0030] The ability for the user to easily switch between modes may reduce the time spent adj usting equipment settings , thereby decreasing overall procedure time and potentially leading to better patient throughput in surgical facilities .

[0031] The control unit is preferably further configured to provide an anti-sticking function . To this end, the control unit preferably provides a device for controlling DC voltage and / or polarity, further preferably including reversing polarity, such that a single and / or series of DC voltage spikes and / or polarity reversals are issued for loosening of sticked tissue and / or preventing tissue from sticking . Amplitude of the voltage spike or spi kes as well as polarity reversals , i f desired, and how frequently they are issued may be varied to achieve a selected ef fect , like preventing tissue sticking or loosening of already sticked tissue . Preferably, the preventing may require a lesser amplitude and / or lower rate of repetition than the loosening which may require a larger amplitude and / or a higher rate of repetition or a single spike of even larger amplitude (which may even exceed 20 Volt , but preferably stays below 50 Volt ) or a combination thereof . This preferable option is particularly useful for - but not limited to - the non-sticking mode .

[0032] The anti-sticking function may be activated manually via the user interface or automatically upon detection of sticked tissue , in particular by the control unit . To this end, a sticking detection device may be provided, which may comprise a sensor detecting that tissue sticks to the hard obj ect , in particular an instrument , or which may be configured for an indirect detection, preferably by determining electrical pa- rameters of the DC and / or AC output of the generator and / or thermal parameters , preferably at the surgical instrument powered by the electrosurgical generator . Preferably, the detection device is configured to detect the status of the electroadhesion, whether it is direct or indirect , bonding as well as releasing of said bond . In a preferred embodiment , the detection device and / or the control unit to which it is communicatively connected is configured to employ arti ficial intelligence (Al ) for evaluation .

[0033] In a preferred embodiment , the electrosurgical generator is configured for monopolar application . The electrosurgical generator being configured for monopolar application enhances the versatility of the device , allowing it to be used for a wide range of surgical procedures that require precise tissue dissection and coagulation including sealing of vessels . In such a monopolar conf iguration, the electrosurgical instrument is usually embodied as a monopolar electrode ( active electrode ) , and a conductive table on which the tissue is placed ( or a separate electrode applied to the tissue ) forms a neutral electrode which is connected to the output of the electrosurgical generator for closing the electrical circuit . The monopolar configuration facilitates the concentration of electrical energy at the active electrode , which can result in more ef ficient cutting and coagulation with reduced collateral tissue damage .

[0034] In a preferred embodiment , the electrosurgical generator is configured for bipolar application . This allows for a more controlled and locali zed application of the electrical energy to the issue , and thus obviates disturbances of surrounding other tissue ( or nerves ) . This is of peculiar advantage for locali zed and / or targeted coagulation, like e . g . sealing of (blood) vessels . Further preferably, the electrosurgical generator is configured for supplying a biopsy instrument , in particular a biopsy probe or needle . Thereby, the DC voltage provided by the generator aids in attracting tissue to be taken for biopsy and keeping it in or at the biopsy probe , like a needle . This allows for a more secure holding of the sampled tissue to the biopsy probe and safe trans fer of the sample tissue during retraction, with reduced risk of the sample tissue getting lost or slipping of f . This is achieved preferably by supplying the biopsy probe with the DC voltage or a combination of HF voltage with the DC voltage once it engages to the tissue to be sampled, thereby improving sticking of the sample tissue to the biopsy probe due to the DC voltage and improved cutting free of the sample tissue upon combination with HF voltage .

[0035] Yet further preferably, the electrosurgical generator is configured for supplying a retractor, in particular a wound or incision retractor . By virtue of this , upon the retractor attaching to the tissue , DC energy is provided, thereby keeping the tissue to be spread apart firmly attached to the retractor . The risk of tissue slipping along and from the reactor is thus reduced, thereby increasing operational safety of the retractors .

[0036] In particular in such circumstances , but not limited thereto , it is preferable that the electrosurgical generator is configured for the HF generator to be switchable to an Of f-state . While the generator is utili zed for supplying e . g . a retractor no HF energy is needed . Similarly with respect to a biopsy probe , however in this respect it may useful to have the generator supplying HF for the way in order to enable the instrument cutting its way in and / or cutting free of the sample tissue , but to be switched of f for the way out , namely the re- tracting step, in order to avoid a negative impact on the transported sample tissue taken or to surrounding tissue .

[0037] Advantageously, the electrosurgical generator is configured for the HF generator to be switchable to an Of f-state . In one embodiment , thi s may be reali zed by switching of f the inverter, e . g . via its inverter controller . Due to such switch- ing-of f , the electrosurgical generator is enabled to provide j ust the DC voltage ( and no HF output ) , which can be beneficial for combination with certain instruments and tasks , like for biopsy probe or for retractors . - In a di f ferent embodiment , which also forms a part of the present invention, the high- frequency generating part may be absent , such that the DC portion only remains . Such a pure electrosurgical DC generator may be an economical alternative i f only the DC part is of interest .

[0038] Preferably, the control unit is configured to supply DC voltage dependent on preset modes , wherein the preset modes may comprise at least one coagulation mode and / or at least one cut mode , and / or an anti-stick mode . This allows for having modes stored in the electrosurgical generator which are designed to provide a certain pattern of DC energy for improved operation, thereby aiding the surgeon and providing improved results .

[0039] In one embodiment thereof , a cut mode is provided having a first stage in which DC energy is supplied initially, and a second stage stopping or reducing supply of DC energy upon detection of electric arcing at the instrument , wherein optionally subsequently in a third stage a lower amount of DC energy is supplied intermittently and preferably also periodically . This allows for an improved initial cut . Traditionally, prior to arcing it happened quite often that unintended sticking occurred, with adverse ef fect on cutting quality . Due to DC en- ergy being suppl ied in said initial phase , the electrode is kept free from sticking until the electric arc ignites . Then the DC is no longer needed and can be switched of f or will be reduced . In order to ensure smooth movement afterwards , a lower amount of DC energy may be provided intermittently in a pulse like manner, the pulses being preferably repeated periodically . This ef fectively provides an anti-stick functionality, providing the surgeon with a smooth gliding experience for movements o f the instrument . - In case electric arcing is lost for any cause , then the two stages of high initial DC supply and reduction subsequent to arcing will be repeated automatically . Thi s is another big benefit for the surgeon . Additionally, a manual triggering of the high initial supply is possible also . For accomplishing this an arcing detector is preferably provided, or an already present arcing detector of the electrosurgical generator may be utili zed .

[0040] In another embodiment thereof , a coagulation mode is provided comprising an end of coagulation action detection, preferably signaled by a main control unit of the electrosurgical generator, and upon such detection supplying of DC energy . Thereby DC energy is provided towards the end of a coagulation action ( this term includes sealing of a vessel ) , e . g . to seal a wound . Providing such DC energy at the end, when the electrosurgical instrument is to be li fted of f , prevents sticking of tissue and therefore considerably lessens the risk of the inadvertent wound re-opening due to sticking of tissue at the instrument which is to be taken away . Briefly stated, such a mode ensures a rather success ful end of a coagulation action . Such a mode is o f special importance for sealing of vessels . - However, the surgeon does not have to wait for the end to be detected, preferably the DC energy supplied can be triggered manually as well . For accomplishing this an end detector is preferably provided, or an already present end detector of the electrosurgical generator may be utili zed . - Additionally, it is beneficial to provide DC energy intermittently and periodically already during the coagulation action, until the end of coagulation is detected ( then more DC energy is to be supplied for improved li ftof f , as j ust described) . The intermittent supply ensures that the instrument will not ( or at least less likely) get stuck in the course of the coagulation, thereby avoiding creating defects at the wound due to stuck tissue . Further, a manual triggering of the high final DC supply is possible as wel l so that the surgeon can li ft of f anytime and does not have to wait for the end detection to engage .

[0041] In yet another embodiment , the control unit is configured to regulate providing DC energy intermittently, preferably periodically, such as to maintain a non-sticking condition . Thereby an "Anti-Sticking" functionality ( or mode ) is achieved . Preferably, the DC energy supplied is to be increased i f sticking is detected . Thereby, sticking is avoided due to DC energy being applied sequentially . The surgeon experiences an instrument that can be moved smoothly and reliably without getting stuck, which is a great benefit in operational experience and improves quality of cutting or coagulation . This preventive Anti-Sticking Functionality is particularly useful for bipolar electrosurgical instruments , which were notoriously di f ficult to be used for smooth bipolar cutting, which becomes much more reliable and provides better results owing to this aspect of the present invention .

[0042] Advantageously, a spark monitor is provided, and the control unit is configured to regulate DC energy such as to be adj usted depending on sparking detected . Thereby, an unwanted increase of sparking can be immediately and automatically counteracted . This is accomplished preferably such that DC energy is increased upon detection of increased sparking, be it in occurrence so that sparking happens more often, and / or in intensity, i . e . the sparking gets more intense . Conversely, DC energy can be decreased on detection of reduced sparking . This provides for more smooth and reliable operation .

[0043] In a further pre ferred embodiment , the electrosurgical generator is configured such that the HF generator generates high frequency in the ultrasound (US ) range . Preferably, the electrosurgical generator is configured for providing both, electrosurgical HF energy in the RF range and ultrasound energy . This allows for simultaneous cutting and coagulation with ultrasonic dissection, which can result in reduced operative time and improved precision in tissue manipulation . The integration of ultrasound with electrosurgery may facilitate the selective targeting of tissue types based on their di f ferent mechanical and electrical properties , potentially improving surgical outcomes and reducing unintended tissue damage . Further, it enables two instruments , one HF and one ultrasound instrument , to be driven by the same electrosurgical generator, or to drive a complex instrument like Thunderbeat (R) of the Olympus Medical company which uses HF and ultrasound within a single instrument .

[0044] Preferably, the electrosurgical generator is part of an electrosurgical system, an endoscopic diagnostic system, a system for inserting or removing an implant or a stent , a system for wound closure , and / or a robot-controlled surgical system . The capability of controlling un-sticking and / or sticking of tissue is a great benefit for any of these system and facilitates the work of the surgeon . Especially in combination with a robot-controlled surgical system, an electrosurgical generator according to the invention, which is enabled to control sticking and unsticking of tissue , is an important benefit for reliable operation of such robotic surgical system . Hitherto , uncontrolled sticking of tissue to an instrument was a maj or drawback and hurdle with respect to practical operation of such robot-controlled surgical systems and were a risk for safety of the patient . This can be overcome by the electrosur- gical generator according to the invention .

[0045] The invention further relates to a system for a medical procedure comprising an electrosurgical generator according to any of the preceding claims , the system being an endoscopic diagnostic system, a system for inserting or removing an implant or a stent , an electrosurgical system, a system for wound closure , and / or a robot-controlled surgical system . All these systems benefit from the positive control of sticking and un-sticking as reali zed by the present invention .

[0046] Preferably, the electrosurgical generator is communicatively connected to a control device of the robot-controlled surgical system, wherein the electrosurgical generator is configured to signal to the control device i f sticking and / or non-sticking condition of tis sue to an instrument is detected . Thereby, an inherent problem of robotic surgery, namely that the robot is unaware of and / or is unable to control tissue sticking with consequential adverse ef fects on the outcome of the surgery performed, can be overcome . Owing to the invention, the robotic system is enabled to positively control sticking and ensure non-sticking, i f required . Further preferably, to this end, the electrosurgical generator is preferably configured such as to establ ish and / or maintain a sticking condition upon direction and command of the robot-controlled surgical system, and / or as to release a sticking of the instrument to the tissue , e . g . due to electroadhesion bonding, and to maintain the non-sticking condition upon direction and command of the robot-controlled surgical system, by controlled DC energy ap- plication. This is a huge benefit for reliability and quality improvement of robotic surgery.

[0047] The invention further relates to use of an electrosurgical generator to perform controlling of tissue sticking to an electrosurgical instrument, wherein the electrosurgical generator according to the invention is employed for tissue control .

[0048] The invention further relates to a method for controlling tissue adhesion during electrosurgical procedures, comprising: a. generating an alternating current (AC) voltage in the kilohertz range for cutting and coagulating / sealing tissue using a high-frequency (HF) generator; b. overlaying a direct current (DC) voltage on the HF generator output to create or release an electroadhesion effect; c. providing a DC voltage in the range of 0 to 20 volts and a current level in the range of 0 to milliamperes; d. modulating the DC voltage based on a desired tissue effect, including controlling switching the DC voltage between an on state, in which the DC voltage is applied, and an off state, in which the DC voltage is not applied.

[0049] The overlay of a DC voltage on the HF generator output to create an electroadhesion effect or release tissue sticking enables the surgeon to control tissue adhesion, thereby reducing the risk of tissue sticking to the surgical instrument, which can lead to tissue trauma or tearing.

[0050] Preferably, said modulating comprises controlling DC voltage, or DC current, or a combination thereof. Advantageously, said modulating further comprises controlling the polarity of the DC voltage to prevent or loosen unintended tissue sticking during the electrosurgical procedures .

[0051] Modulating the DC voltage based on the desired tissue ef fect , including controlling the polarity, provides the surgeon with a tool to fine-tune the surgical procedure , enhancing the ability to prevent or release unintended tissue adhesion without interrupting the surgical workflow .

[0052] Preferably, the DC voltage is set to be a low voltage up to 20 Volt , preferably up to 10 Volt and in particular at least 5 Volt , and / or for DC current in the range up to 200 mA, preferably up to 80 mA and in particular at least 2 mA. These values ensure patient safety .

[0053] In a development , the method further comprises the DC voltage being applied intermittently alongside the HF mode .

[0054] Applying the DC voltage intermittently alongside the HF mode allows for a dynamic control of tissue adhesion, enabling the surgeon to apply the electroadhesion ef fect only when needed, which can improve the ef ficiency of the surgical procedure .

[0055] The controlling of the polarity preferably comprises reversing the polarity of the DC voltage . By reversing the polarity, it can be controlled when the DC voltage will be reversed such that sticked tis sue can be loosened or said loosening stops and / or sticking of tissue will be ef fected or released . Reversing of the polarity thus allows determining a begin and an end of the sticking and / or loosening of said tissue , resp . .

[0056] The intermittent applying of the DC voltage and / or reversing of polarity may further preferably be controlled such as to control shape and / or duration of the DC voltage and energy supplied, e.g. full ON / OFF (square-like) , increasing ON and decreasing OFF (triangle-like) , increasing ON and sudden OFF (sawtooth) or sudden ON and decreasing OFF (sawtooth II) , etc.

[0057] In a development, the method further comprises at least one of a microcontroller (pC) , a central processing unit (CPU) , a digital signal processor (DSP) , an application specific integrated circuit (ASIC) and / or a field-programmable gate array (FPGA) .

[0058] The inclusion of a microcontroller, CPU, DSP, ASIC, and / or FPGA allows for sophisticated control algorithms and real-time processing capabilities, which can enhance the precision and responsiveness of the method.

[0059] The use of these programmable components enables the method to be easily updated or modified through software changes, providing flexibility to adapt to different applications or improvements over time.

[0060] In a development, the method further comprises selecting between a non-sticking mode and a sticking mode of operation using a user interface.

[0061] Offering a selectable non-sticking mode and a sticking mode of operation through a user interface provides the operator with greater control over the procedure, allowing for customization based on specific surgical requirements or preferences.

[0062] The ability to switch between modes can potentially reduce the risk of tissue damage by minimizing unwanted adhesion, thereby improving patient outcomes and reducing recovery times.

[0063] Preferaby, the method further comprises an anti-sticking function. By providing such a function, the DC voltage and polar- ity, further pre ferably including reversing polarity, are controlled such that a single and / or series of DC voltage spikes and / or polarity reversals are issued for loosening of sticked tissue and / or preventing tissue from sticking . Amplitude of the voltage spi ke or spikes as well as polarity reversals , i f desired, and how frequently they are issued may be varied to achieve a selected ef fect , like preventing tissue sticking or loosening of already sticked tissue . Preferably, the preventing may require a lesser amplitude and / or lower rate of repetition than the loosening which may require a larger amplitude and / or a higher rate of repetition or a single spike of even larger amplitude (which may even exceed 20 Volt , but preferably stays below 50 Volt ) or a combination thereof . This preferable option is particularly useful for - but not limited to- the non-sticking mode .

[0064] The anti-sticking function may be activated manually via the user interface or automatically upon detection of sticked tissue , in particular by the control unit or a detecting device which is a part of or communicatively connected to the control unit . Said automatic detecting may be direct , preferably employing a sensor detecting that tissue sticks to the hard obj ect , particularly the instrument , or indirect , preferably by determining electrical parameters of the DC and / or AC output of the generator , and / or thermal parameters , preferably at the surgical instrument powered by the electrosurgical generator .

[0065] In a development , the method further comprises an electrosurgical procedure being performed using a monopolar application .

[0066] Performing an electrosurgical procedure using a monopolar application can be advantageous for targeted tissue ablation, as it allows for focused energy delivery to the area of interest , leading to precise cutting or coagulation . Monopolar electrosurgery often requires simpler instrumentation and can be more cost ef fective compared to other surgical methods , making it accessible for a wide range of healthcare facilities .

[0067] In a development , the method further comprises an electrosur- gical procedure being performed using a bipolar application .

[0068] The use of bipolar application in electrosurgical procedures can result in reduced collateral tissue damage since the electrical current passes between two closely spaced electrodes , rather than through the entire body .

[0069] Bipolar electrosurgery can of fer improved hemostasis and reduced risk of electrical burns to the patient , as the energy is confined to the area between the electrodes , enhancing procedural safety .

[0070] In a development , the method further comprises an electrosurgical procedure being combined with ultrasound (US ) technology .

[0071] The integration of ultrasound can facilitate the identi fication of critical structures such as blood vessels or nerves , thereby reducing the likelihood of inadvertent damage and enhancing the safety profile of the electrosurgical method .

[0072] For further details on the method and the electrosurgical generator and system involved, reference to the foregoing description thereo f is made .

[0073] BRIEF DESCRIPT ION OF DRAWINGS

[0074] The present disclosure is illustrated by way of example and not limited in the accompanying figures . Embodiments of the application will now be described with reference to the attached drawings :

[0075] Fig. 1 Lab Setup for confirming electroadhesion effect ;

[0076] Fig. 2 Confirming electroadhesion effect with Carbon electrode ;

[0077] Fig. 3 shows a schematic diagram of a surgical generator according to a first embodiment;

[0078] Fig. 4 shows a detail of the embodiment of Fig. 3;

[0079] Fig. 5 shows a functional diagram for voltage overlay of the first embodiment;

[0080] Fig. 6 shows a schematic diagram of a surgical generator according to a second embodiment;

[0081] Fig. 7 shows a partial view of a third embodiment as part of a system further comprising a surgical robot;

[0082] Fig. 8A-C shows HF voltage, DC voltage and the overlaid voltage for a HF / DC mode of operation;

[0083] Fig. 9 shows DC voltage for a DC / DC mode of operation;

[0084] Fig. 10 shows a variant of the third embodiment using a monopolar electrode and a DC-supplied retractor;

[0085] Fig. 11 shows a detail view of a DC controller with its function modules;

[0086] Fig. 12A, B show an exemplary HF / DC pattern for a cut mode; Fig . 13A, B show an exemplary HF / DC pattern for a coagulation mode ;

[0087] Fig . 14 shows Flowchart 1 ; and

[0088] Fig . 15 shows Flowchart 2 .

[0089] DETAILED DESCRI PTION

[0090] Fig . 1 presents a photograph of a real-li fe working environment for testing or assembling an electrosurgical generator 1 . On the left , there is a piece of electronic test equipment , which would output an alternating current for cutting and coagulating tissue . Adj acent to it , and spread across the bench, are miscellaneous tools and components which might be associated with the setup and maintenance of such a generator . In the center, elevated on a red platform, is an unidenti fiable device that could be related to the direct current voltage source superimposing a DC voltage on the HF output . This aspect of the setup would correspond to creating an electroadhesion ef fect . On the right , a larger, more complex machine with a user interface 11 that includes several displays and control inputs is visible . This is the main body of the electrosurgical generator 1 with integrated control units . The control units could comprise microcontrollers , CPUs , and / or FPGAs , and serve to modulate the DC voltage , including controlling its polarity, to achieve the desired tissue ef fects and prevent or loosen unintended tissue sticking as per the patent claims . There are also cables , connecting the various components to provide power and control signals . With respect to speci fic modes of operation such as non-sticking mode or sticking mode of operation, as mentioned in the patent claims and the foregoing portion of the description, reference is made to Fig . 7A-C, Fig . 10 , Fig . 12A, B and Fig . 13A, B which will be described below .

[0091] The image presented in Fig . 2 does not display a traditional patent figure but shows what appears to be an actual application of an electrosurgical process . In the foreground, a pair of forceps or clamps with red insulation on the handles and metal tips , which are holding a piece of body tissue is shown . The tissue is presumably undergoing a surgical procedure involving electrosurgery . While the setup of the electrosurgical generator 1 is not visible in this photograph, the image indirectly references these elements through the action depicted . The photograph does not explicitly show the high- frequency generator output , direct current overlay, control unit , or user interface 11 discussed in the claims . Moreover, the figure does not showcase the voltage or current levels being applied, the modulation of the DC voltage , or control of the polarity . The photo , however, could be illustrating the practical application of the patented electrosurgical technology, depicting the result of the interaction between the instrument and the tissue , which might involve the claimed electroadhesion ef fect , where electricity is used to manipulate biological tissue during a surgical procedure .

[0092] An exemplary embodiment for an assembly of an electrosurgical generator according to a first embodiment of the present is illustrated in Fig . 3 . The electrosurgical generator which is designated as a whole by reference numeral 1 comprises within a housing 11 a power supply 2 which is connected to an electrical power source (not shown) which may be an electricity grid, like AC mains in a building, or an of f-grid source of electric energy, like a 12 Volt or 24 Volt battery of a vehicle or in a mobile hospital . This electrical energy is fed to an inverter 3 which is configured to generate HF energy which is routed via fi lter 4 and a step-up trans former 5 and further via an output line 8 towards an output socket 16 to which an electrosurgical instruments 9 is to be connected . The inverter 3 generates alternating current in a selectable voltage range at a high frequency up to a few kilovolts at selectable frequencies up to 4000 kHz as it may be as low as 200 kHz ( radiofrequency range ) . In the depicted embodiment the inverter 3 and its inverter control are configured for generation in the radiofrequency ( RF) range . - It is to be noted that in speci fic cases li ke an electrosurgical generator 1 being enabled for driving an ultrasound instrument 9" the generated frequency may also be in the ultrasound range from about 20 kHz to 200 kHz . The electrosurgical instrument 9" which is to be plugged into the output socket 16 can accordingly be supplied with radiofrequency energy as well as ultrasound energy, or a combination thereof .

[0093] Constitution and operation of the basic elements of electrosurgical generator 1 are conventional and are known to the person skilled in the art , therefore it will not be addressed here in full detail for the sake of brevity . Operation of the electrosurgical generator 1 is controlled by a main control unit 12 which is internally connected to various internal components via communication lines , of which a few only are shown in the Figures o f the present application . The main control unit 12 is communicatively connected to a user interface 11 which may be touchscreen configured for user interaction, namely displaying about the generator and its operation and taking instructions and commands form the user, or a conventional key-based used interface in conj unction with a display may be employed . Further connected to the main control unit 12 are an inverter controller 30 which is configured to determine control pulses to current valves of the inverter 3 based on controlling signals emitted by the main control unit 12 , in order to ef fect provisioning of AC voltage in the high frequency range by the inverter 3 and its current valves .

[0094] The filter 4 which is arranged subsequently to the inverter 3 (" subsequently" refers to the flow of energy towards the output socket 16 ) is preferably configured as a low pass filter . Thereby emission of noise at higher frequencies , in particular unwanted harmonics , is reduced . Subsequently, the step-up trans former 5 is configured to bring the AC voltage generated by the inverter 3 to a higher voltage level for supplying the electrosurgical instrument 9 which is to be connected to the output socket 16 . In Fig . 3 , the instrument 9 is equipped with a bipolar electrode 92 . Subsequent to the step-up trans former 5 a blocking capacitor 6 is provided, which blocks conveyance of any DC current which may stem form the inverter 3 . Between said blocking capacitor 6 and functionally ( and in many cases also physically) j ust prior to the output socket 16 a RF voltage and current sensor is provided .

[0095] Further, along the output line 8 between the blocking capacitor 6 and the output socket 16 , a DC energy unit 7 is arranged providing DC voltage and DC energy to the output line 8 . The DC voltage is overlaid on the AC (HF) voltage provided by the inverter 3 This overlaying of DC voltage is ef fected by said DC Energy Unit 7 .

[0096] The DC Energy Unit 7 , as depicted in Fig . 4 , comprises a DC Voltage Source 71 which is connected to the output line 8 such that DC voltage emitted by the DC Voltage Source 81 is fed into the output line 8 as an overlay voltage . To this end, the DC voltage source 71 is connected with both of its terminals by means of two DC interconnectors 73 , one for connection to an active electrode (AE ) and the other for connection to the a neutral electrode (NE ) of the output line 8 leading to the output socket 16 . By means of the DC interconnectors 73 the connection of the DC Voltage Source 71 to the output line 8 is switchable between an "ON State" in which DC voltage and current is fed into the output line 8 , and an "OFF Stage" , in which the feeding is interrupted . For this switching, a DC Power switch 72 is provided at either interconnector 73 , the power switch 72 being preferably embodied e . g . as a FET switch . Settings of the DC Voltage Source 81 as well as switching status of the DC Power Switches 72 are controlled by a DC controller 70 . The DC controller is communicatively coupled to the main control unit 12 , in order to synchroni ze operation of the DC energy unit with main operation of the elec- trosurgical generator 1 , in particular its inverter 3 .

[0097] For measuring the overlaid DC current as well as voltage , a DC current and voltage sensor assembly 79 is provided . It is configured for measured DC current and voltage and to supply corresponding signals for measured DC current and voltage to both, the DC controller 70 and, preferably via a feedback circuit 15 , to the main control unit 11 .

[0098] Functionally, the DC Energy Unit 7 ( i ) delivers of DC energy by means of its DC voltage source 71 as well as ( ii ) feeding the DC energy at the interconnectors 73 into the output line 8 , thereby adding said DC energy to any HF energy present as delivered by the inverter 3 . This functionality (herein briefly termed as "overlaying" ) is shown in Fig . 5 .

[0099] A second embodiment of the invention is shown in Fig . 6 . It shows a part of an electrosurgical generator, namely the generation of RF by the inverter and the subsequent elements filter 4 ' , step-up trans former 5 , blocking capacitor 6 and DC Energy Unit 7 supplying an output socket 16 for an electrosurgical instrument 9 as explained above with respect to Fig . 1 and Fig . 3 . Like elements bear the same reference numerals . However, filter 4 ' may be configured as a band-pass or high-pass filter . Additionally, the embodiment depicted in Fig . 6 comprises a second HF generation branch for generating AC in the ultrasound (US ) range . The basic form of said ultrasound frequency is also generated by the inverter 3 , although it may also be possible to provide a second dedicated to j ust generating ultrasound frequency . Yet , the single inverter concept 3 as shown in Fig . 3 makes better use of the programmable capabilities of an inverter, which is thus enabled to provide two selectable frequencies at once ( one in the RF range , the other in the US range , even with a random selectable , non-integer frequency relation) . The ultrasound frequency thus generated by the inverter 3 is fed into a second HF branch, formed by a low-pass filter 4" having a roll-of f frequency at or above an upper edge of the US frequency range but below the RF range , thereby allowing j ust the US frequency portion as generated by the inverter 3 to pass to the step-up trans former 5" and subsequently to an US output socket 16" into which an ultrasound instrument 9" comprising an ultrasound blade 96 may be plugged . A second DC energy unit 7" may be provided between the step-up trans former 5" and the US output socket 16" . - It is to be noted that the two output sockets 16 , 16" may be combined into one to form a combined output socket . This can be advantageous for supplying an advanced electrosurgical instrument , like Thunderbeat (R) of Olympus Medical .

[0100] However, it is not strictly necessary that the overlaying, i . e . superimposing of DC into the output line 8 , happens at a location adj acent to the DC voltage source 71 . The DC energy unit 7 may be located at a location separate from the HF output line 8 . Particularly, variants are shown in Fig . 7 where the interconnector 73 ' for inj ection of the DC voltage may be located outside of a housing of the electrosurgical generator 1 at a cable leading from the electrosurgical generator 1 to the instrument 9, or even like the interconnector 73" at the electrosurgical instrument itself. In such a variant, where the interconnector 73' is located outside of the housing of the electrosurgical generator 1, the DC voltage as provided by the DC voltage source may or may not be potential-coupled to the same neutral potential as the AC voltage generated by inverter 3. This is applicable with respect to all embodiments where the interconnector 73' , 73" is not located within the housing of the electrosurgical generator 1 and / or when a separate output socket 16' for DC is provided.

[0101] The relation of HF provided by the inverter 3 and DC provided by the DC energy is illustrated in Fig. 8A-C. A sample HF frequency as generated by the inverter 3 and processed by the filter 4, step-up transformer 5 and the blocking capacitor 6 is shown in Fig. 8A. This is a typical RF output of an electrosurgical generator. In Fig. 8B a DC voltage is shown, which in the example is rather low about 5 Volt. Towards the end of the HF application, such a rather low DC voltage of 5 Volt will be applied having a current of about 20 to 30 mA, for a duration of several seconds, e.g. up to 30 seconds. At a later point of time a second DC voltage is shown which may be a negative voltage. At the interconnectors 73, both, the HF and the DC will be overlaid, resulting in a combined voltage as shown by the solid line in Fig. 8C which is to be supplied at the output socket 16.

[0102] As it can be seen in Fig. 8C, conventional HF voltage is initially output for energizing the HF electrosurgical instrument, e.g. a monopolar cutting electrode acting on tissue being in contact with a neutral electrode, like shown in Fig. 7. This is depicted as a first phase I in Fig. 8C. During a second phase II, the DC voltage as shown in Fig. 8B is overlaid to the HF voltage . This is depicted as a second phase I I ( for reference with the DC voltage depicted as a dashed line ) . Finally, after supply of HF ended, DC voltage may be applied again . The DC may have the same or a reverse polarity, the latter case being shown as a phase I I I in Fig . 8C . Thereby, a mode for combined output of HF and DC is shown .

[0103] An example for applying such a combined HF and DC voltage may be explained with reference to the configuration as shown in Fig . 7 . There a biopsy probe 97 may be utili zed as the elec- trosurgical instrument . It is configured roughly similar to an oversi zed needle with a cavity being spacious enough for taking in a portion of sample tissue . The biopsy probe is made of conductive material . In order to bring the biopsy probe 9 ' to the location where tissue is to sampled, HF energy may be applied in phase I such that the instrument 9 ' may cut its way to said location . Upon reaching it , DC voltage is applied additionally in phase I I , thereby a portion of sample tissue which is cut free by the HF energy will be bonded by the DC voltage to a tissue holding cavity of the biopsy probe 97 . Upon retracting the biopsy probe 97 the HF energy may be further supplied and subsequently being switched of f . Finally, DC voltage will be applied again, preferably with a reversed polarity, in phase I I I for releasing the sampled tissue from the biopsy probe 97 .

[0104] Such capability is a special benefit i f the electrosurgical generator 1 of the invention is to be employed as a part of a robotic surgery system, as indicated by reference numeral 90 . In particular the increased reliability in terms of keeping the sample tissue firmly attached due to the DC voltage applied is a key benefit for enabling a robotic system to conduct taking a biopsy probe in a reliable manner . A different mode is shown in Fig. 9. According to this mode, the electrosurgical generator 1 outputs DC voltage only. No HF voltage will be output in this mode. Initially, no DC energy is to be provided, and the DC voltage thus stays at zero. At some time later, when the electrosurgical instrument is in contact with tissue to be treated, a low DC voltage will be provided which is at maximum 20 Volt. In the present example a voltage between 5 Volt and 10 Volt may be provided. This will happen in phase II for a certain time duration, preferably ranging between 20 seconds and 3 minutes. For example a time duration of 60 seconds may be selected. As a result of this providing of DC energy, the tissue will adhere to an electrode of the electrosurgical instrument by virtue of electroadhesion. This kind of bonding ("sticking") is expected to persist even if thereafter in phase III the DC voltage is be removed. For effecting a release, a DC voltage will be applied again in phase IV. In this phase IV, in order to "unstick" the tissue in a controlled manner, the DC voltage is preferably applied with inverted polarity. For example, by applying a voltage of just 5 Volt for 20 seconds, the bond of the tissue to the electrode can be released and the electroadhesion effect can be reversed, thereby "unsticking" the tissue from the electrosurgical instrument in a controlled manner.

[0105] A pure DC voltage may be applied to e.g. a retractor. In Fig. 10 a variant of the third embodiment is shown using an electrosurgical instrument 9 having a monopolar electrode 93 and further a DC-supplied retractor 98. The monopolar electrode 93 is configured to be used together with a neutral electrode 94 providing a return line for the HF current. Said neutral electrode is connected to tissue 99 to be treated, e.g. by means of a patch electrode or by means of being a conductive table on which the tissue 99 to be treated is placed. Said instrument 9 with the monopolar electrode as well as the neutral electrode 94 are connected at the output socket 16 of electro- surgical generator, as e.g. shown in Fig. 7. The retractor which may be embodied as an incision retractor 98 is connected at the DC output connector 16' , more precisely to an upper potential of the DC voltage. The incision retractor is at least partly made of conductive material, in particular in that region which forms an attachment surface for tissue.

[0106] On outputting a DC voltage like depicted in Fig. 9, the tissue to be held open by the incision retractor 98 is bonded to the incision retractor 98 by virtue of electroadhesion once the DC voltage is applied as depicted in phase II of Fig. 9. Accordingly, upon the retractor 98 attaching to the tissue, DC energy is provided, thereby keeping the tissue to be spread apart firmly attached to the retractor. Due to this "sticking" effect, any risk of tissue slipping along and from the retractor is thus reduced, thereby increasing operational safety of the retractors. Due to persistence of the electroadhesion effect the DC voltage may be removed thereafter, as shown in phase III of Fig. 9. However, optionally the DC voltage may be provided continuously or periodically for the time the retractor 98 is applied in order to increase safety against slipping. Once the surgery is performed and the retractor 98 is no longer needed, the DC voltage will be switched off (Phase III) and preferably subsequently applied with reversed polarity (Phase IV) , thereby effecting a reliable release of the bonding to the tissue. The tissue will become "unstick" and the retractor 98 may be removed without harming the tissue. By virtue of this, operational efficiency of the incision retractor 98 can be increased and risks, in particular due to unintended sticking of the tissue, can be reduced.

[0107] For controlling providing DC energy, the DC Controller 70 is equipped with several function modules. It comprises a stick ing control module 75 which is operationally connected to a spark monitor 74 , a cycle control module 76 , a repulsion unit 77 , and a sticking detection device 78 . Further, the DC controller 70 is communicatively connected to an Initial Cut Detector 13 and an End Detector 14 of main control unit 12 . The Initial Cut Detector 13 is configured to signal the point of time when a cutting action begins , i . e . when the electrosurgi- cal instrument is brought into contact with the tissue , as it can be detected e . g . by monitoring flow of HF energy . Similarly, the spark monitor 74 is configured to monitor HF voltage , current , power / energy for preprogrammed characteristics of sparking, and when such characteristics are identi fied to provide a spark detection signal .

[0108] Special Cut Mode

[0109] A special cut mode with supply of DC voltage is shown in Fig . 12A, B . This mode features a first stage I , during which DC energy is supplied initially, and a second stage I I , during which supply of DC energy is reduced or stopped upon detection of electric arcing at the electrosurgical instrument 9 , by virtue of the spark monitor 74 . This allows for an improved initial phase of the cutting . Hitherto , in the prior art it was encountered frequently that unintended sticking occurred prior to formation of the arc - leading to an adverse ef fect on cutting quality . In the special cut mode according to the invention DC energy will be delivered automatically at the first stage . Due to DC energy being supplied in said initial phase , the electrode is kept free from sticking until the electric arc ignites . This igniting of the electric arc is detected by the spark monitor 74 at point marked in Fig . 12A, B . Then the DC energy is no longer needed and can be switched of f or will be reduced . Optionally, subsequently a lower amount of DC energy may be provided intermittently in a pulse like manner in order to ensure a smooth movement afterwards in a third stage I I I . The pulses being pre ferably repeated periodically . This ef fectively provides an anti-stick functionality which avoids occurrence of unintended sticking during further cutting, and thus ef fectively avoids the adverse consequences of sticking on quality of the cutting . The surgeon enj oys a smooth gliding experience for movements of the electrosurgical instrument being powered according to this mode , and the quality of the cutting is improved .

[0110] In case electric arcing is lost for any cause , then the two stages I , I I of high initial DC supply and reduction of DC subsequent to arcing will be repeated automatically . This is another big benefit for the surgeon .

[0111] Additionally, a manual triggering of the high initial supply is possible also . For accomplishing this an arcing detector is preferably provided, or an already present arcing detector of the electrosurgical generator may be utili zed . Further, optionally a manual activation of the DC supply according to stages I and I I may be provided by means of an triggering an instrument switch 91 .

[0112] Special Coagulation Mode

[0113] A special coagulation mode for improving quality of tissue sealing by coagulation is provided and is depicted in Fig . 13A, B . This coagulation mode features a special configuration towards at the end of a coagulation action .

[0114] During the task of sealing tissue , i . e . closing a vessel or sealing a wound / incision, the surgeons performs coagulation using the electrosurgical instrument . When such an coagulation action ( this term includes sealing of a vessel ) comes to an end, the electrosurgical instrument needs to be li fted of f . In order to facilitate this , the special coagulation mode features an end of coagulation action detection, preferably automatically detected and signaled by the end detector 14 of the main control unit 11 . The detection of the coagulation coming to end is marked in Fig . 13A, B by an asterisk Upon such detection, DC energy is supplied by the DC Energy Unit 7 in stage I . By virtue of this , DC energy is provided in addition to the HF energy towards the end of a coagulation action, e . g . to seal a wound . Providing such DC energy at the end, when the electrosurgical instrument is to be li fted of f , prevents sticking of tissue and therefore considerably lessens the risk of the inadvertent wound re-opening due to sticking of tissue at the electrosurgical instrument which is to be taken away . Preferably, when supplying of the DC energy is about to be terminated, preferably an end signal is ( acoustically or optically) given to the surgeon indicating that the electrosurgical instrument may now be li fted of f . Providing such an end signal is marked by a symbol in Fig . 13A, B . Summari zing, such a mode ensures a rather success ful end of a coagulation action . Such a mode is of special importance for sealing of a vessel . - Optionally, when such an end signal is about to be given then the DC voltage providing the DC energy will be reversed by a repulsion unit . The DC voltage having reversed polarity provides for an improved and more reliable release of electroadhesion and thus further enhances reliability .

[0115] However, the surgeon does not necessarily have to wait for the end of coagulation to be detected . Optionally, the DC energy supplied can be triggered manually as well , e . g . by activation of the instrument switch 91 . Thereby, a manual triggering of the high final DC supply including the optional reversion of DC voltage can be ef fected so that the surgeon can li ft of f anytime and does not have to wait for the end detection to engage .

[0116] Anti-Stick Mode

[0117] Additionally, it may be beneficial to provide DC energy intermittently and periodically already during the coagulation action . The intermittent supply ensures that the instrument will not ( or at least less likely) get stuck in the course of the coagulation . Thi s is shown as a stage I I I in Fig . 13A, B . This stage I I I is essentially similar to Stage I I I of the Special Cut Mode , and for details reference is made the description thereof given above .

[0118] Moreover, such an anti-stick mode may be ef fected by the surgeon via the user interface 14 independently from any end or arc detection . Thereby, a reduced amount of DC energy may be provided intermittently in a pulse like manner as governed by a cycle control module 76 in order to ensure a smooth movement of the electrosurgical instrument without any sticking to tissue . The pulses are preferably repeated periodically, as governed by the cycle control module 75 . I f sticking occurs anyway as detected by a sticking detector, then cycle control module 75 may increase the cycle rate , and / or the sticking control module 75 may increase duration of the pulses or DC voltage . All thi s leads to the surgeon enj oying a smooth gliding experience for movements of the electrosurgical instrument being powered according to this mode , improving handling of the electrosurgical instrument 9 and ultimately of the work performed therewith, to the benefit of the patient .

[0119] For ease of reference , simpli fied flowcharts are provided in Fig . 14 and 15 . Fig . 14 shows the following steps : The disclosed invention includes a high- frequency (HF) generator that is configured to output an alternating current (AC ) voltage in the kilohertz range for the purpose of cutting and coagulating tissue 200 . Additionally, a direct current ( DC ) voltage source is provided, which overlays 201 a DC voltage on the output of the HF generator to create an electroadhesion ef fect . The DC voltage source is speci f ically configured 202 to provide a voltage level in the range of 0 to 20 volts and a current level in the range of 0 to 200 milliamperes . To further enhance the functionality of the invention, a control unit 11 is included . This control unit 11 is configured to modulate the DC voltage based on a desired tissue ef fect . The modulation process involves controlling 203 the polarity of the DC voltage to prevent or loosen unintended tissue sticking during electrosurgi- cal procedures . By modulating the DC voltage in this manner, the control unit 11 ensures that the electrosurgical procedures are performed with precision and accuracy, minimi zing any potential complications or unintended tissue adhesion .

[0120] Fig . 15 shows the following steps : The disclosed invention relates to a system and method for generating 204 an alternating current (AC ) voltage in the kilohertz range for cutting and coagulating tissue using a high- frequency (HF) generator . In one aspect , the invention involves overlaying 205 a direct current ( DC ) voltage on the HF generator output 5 to create an electroadhesion ef fect . This is achieved by providing 206 a DC voltage 4 in the range of 0 to 20 volts and a current level in the range of 0 to 200 milliamperes , preferably up to 80 mA. The DC voltage i s further modulated 207 based on a desired tissue ef fect , wherein the polarity of the DC voltage is controlled to prevent or loosen unintended tissue sticking during the electrosurgical procedures .

Claims

Patent Claims1. An electrosurgical generator for treating body tissue, comprising : a. a high-frequency (HF) generator (3) configured to output electrical energy to a surgical instrument, said electrical energy being an alternating current (AC) voltage in the kilohertz range for cutting and coagulating tissue ; b. a direct current (DC) voltage source (7) overlaying a DC voltage on the HF generator output to create or release an electroadhesion effect; c. wherein the DC voltage source (7) is configured to provide a voltage level in the range of 0 to 20 volts and a current level in the range of 0 to 200 milliamperes; d. a control unit (70) configured to modulate the DC voltage based on a desired tissue effect, wherein the modulation includes controlling switching the DC voltage between an on state, in which the DC voltage is applied, and an off state, in which the DC voltage is not applied.

2. The electrosurgical generator of claim 1, wherein the control unit (70) is configured such that modulation comprises controlling DC voltage or DC current or a combination thereof.

3. The electrosurgical generator of claim 1 or 2, wherein the modulation further comprises controlling polarity of the DC voltage to prevent or loosen unintended tissue sticking during electrosurgical action.4 . The electrosurgical generator of claim 3 , wherein controlling the polarity of the DC voltage comprises reversing the polarity of the DC voltage .5 . The electrosurgical generator of any of the preceding claims , wherein the DC voltage is applied intermittently alongside the HF mode .6 . The electrosurgical generator of any of the preceding claims , wherein the control unit is preferably configured to control duration of application of the DC voltage and / or DC energy to be supplied to the tissue .7 . The electrosurgical generator of any of the preceding claims , wherein the DC voltage is a low voltage up to 20 Volt , preferably up to 10 Volt and in particular at least 5 Volt , and / or for DC current in the range up to 200 mA, preferably up to 80 mA and in particular at least 2 mA.8 . The electrosurgical generator of any of the preceding claims , wherein an electrode of the surgical instrument ( 9 ) is comprised of a material which features a positive Standard Electrode Potential (E° ) .9 . The electrosurgical generator of any of the preceding claims , further comprising a user interface ( 14 ) configured to allow a user to select between a non-sticking mode and a sticking mode of operation .10 . The electrosurgical generator of any of the preceding claims , wherein the control unit ( 70 ) is further configured to provide an anti-sticking function, preferably the control unit preferably comprising a device for controlling DC voltage and polarity ( 75 , 76 , 77 ) , which further preferably is configured for reversing polarity, suchthat a single and / or series of DC voltage spikes and / or polarity reversals are issued for loosening of sticked tissue and / or preventing tissue from sticking.

11. The electrosurgical generator of claim 10, wherein a sticking detection device (78) may be provided, the sticking detection device (78) being preferably configured for being automatically activated upon detection of sticked tissue.

12. The electrosurgical generator of any of the preceding claims, wherein the electrosurgical generator (1) is configured for monopolar application.

13. The electrosurgical generator of any of the preceding claims, wherein the electrosurgical generator (1) is configured for bipolar application.

14. The electrosurgical generator of any of the preceding claims, wherein the electrosurgical generator (1) is configured for supplying a biopsy instrument, in particular a biopsy probe (97) or needle, preferably by supplying it with the DC voltage or a combination of HF voltage with the DC voltage.

15. The electrosurgical generator of any of the preceding claims, wherein the electrosurgical generator (1) is configured for supplying one or more retractors (98) , in particular wound or incision retractors, preferably by supplying IT with the DC voltage or a combination of HF voltage with the DC voltage.

16. The electrosurgical generator of either of the two immediately preceding claims, wherein the control unit (70) is configured for supplying DC energy to the biopsy probe( 97 ) upon engaging to the tissue ( 99 ) to be sampled, and / or to the retractor ( 98 ) upon their attachment to the tissue ( 99 ) to be kept apart .17 . The electrosurgical generator of any of the preceding claims , wherein the electrosurgical generator is configured for the HF generator ( 3 ) to be switchable to an Of f- state .18 . The electrosurgical generator of any of the preceding claims , wherein the control unit ( 70 ) is configured to supply DC voltage dependent on preset modes , wherein the preset modes may comprise at least one coagulation mode and / or at least one cut mode , and / or an anti-stick mode .19 . The electrosurgical generator of the preceding claim, wherein a cut mode is provided having a first stage in which DC energy is supplied at the beginning, and a second stage stopping or reducing DC supply upon detection of electric arcing at the instrument , wherein optionally subsequently in a third stage a lower amount of DC energy is supplied intermittently and periodically .20 . The electrosurgical generator of the preceding claim, wherein the first and second stage are repeated upon detection of a loss of electric arcing .21 . The electrosurgical generator of claim 18 , wherein a coagulation mode is provided comprising an end of coagulation action detection, preferably signaled by a main control unit of the electrosurgical generator, and upon such detection supplying of DC energy, wherein optionally the polarity of the DC voltage is reversed prior to shutting of f DC .22 . The electrosurgical generator of the preceding claim, wherein intermittently and periodically DC energy is supplied during a coagulation action until the end of coagulation is detected .23 . The electrosurgical generator of any of the preceding claims , wherein the control unit ( 70 , 76 ) is configured to regulate providing DC energy intermittently, preferably periodically, such as to maintain a non-sticking condition, and the DC energy supplied is to be increased i f sticking is detected .24 . The electrosurgical generator of any of the preceding claims , wherein a spark monitor ( 74 ) is provided, and the control unit is configured to regulate DC energy such as to be adj usted depending on sparking detected, preferably such that DC energy is increased upon detection of increased sparking, in occurrence and / or intensity, and decreased on detection of reduced sparking .25 . The electrosurgical generator of any of the preceding claims , wherein the electrosurgical generator is configured such that the HF generator generates high frequency in the ultrasound (US ) range , preferably in combination with electrosurgical HF energy in a RF range .26 . The electrosurgical generator of any of the preceding claims , wherein the control unit comprises at least one of a microcontroller (pC ) , a central processing unit ( CPU) , a digital signal processor ( DSP ) , an application speci fic integrated circuit (AS IC ) and / or a field-programmable gate array ( FPGA) .27 . The electrosurgical generator of any of the preceding claims , wherein the electrosurgical generator is part ofan electrosurgical system, an endoscopic diagnostic system, a system for inserting or removing an implant or a stent, a system for wound closure, and / or a robot-controlled surgical system.

28. A system for a medical procedure comprising an electrosurgical generator according to any of the preceding claims, the system being an endoscopic diagnostic system, a system for inserting or removing an implant or a stent, an electrosurgical system, a system for wound closure, and / or a robot-controlled surgical system (90) .

29. The system of claim 28, wherein as a part of the robot- controlled surgical system (90) the electrosurgical generator is communicatively connected to a control device( 90 ’ ) of the robot-controlled surgical system (90) , wherein the electrosurgical generator (1) is configured to signal to the control device (90' ) if sticking and / or non-sticking condition of tissue to an instrument is detected .

30. The system of claim 29, wherein the electrosurgical generator is configured such as to establish and / or maintain a sticking condition upon direction and command of the robot-controlled surgical system (90) , and / or as to release a sticking of tissue to the instrument and to maintain a non-sticking condition upon direction and command of the robot-controlled surgical system (90) , by controlled DC energy application.

31. Use of an electrosurgical generator to perform controlling of tissue sticking to an electrosurgical instrument (9) , wherein a the electrosurgical generator according to any of the preceding claim is employed.

32. A method for controlling tissue adhesion during electro- surgical procedures, comprising: a. generating an alternating current (AC) voltage in the kilohertz range for cutting and coagulating / sealing tissue using a high-frequency (HF) generator; b. overlaying a direct current (DC) voltage on the HF generator output to create or release an electroadhesion effect; c. providing a DC voltage in the range of 0 to 20 volts and a current level in the range of 0 to 200 milliamperes; d. modulating the DC voltage based on a desired tissue effect, including controlling switching the DC voltage between an on state, in which the DC voltage is applied, and an off state, in which the DC voltage is not applied.

33. The method of claim 31, wherein said modulating comprises controlling DC voltage, or DC current, or a combination thereof .

34. The method of claim 31 or 33, wherein said modulating further comprises controlling the polarity of the DC voltage to prevent or loosen unintended tissue sticking during the electrosurgical procedures.

35. The method of the preceding claim, wherein controlling the polarity of the DC voltage comprises reversing the polarity of the DC voltage.

36. The method of any of claims 31 to 35, wherein the DC voltage is applied intermittently alongside the HF mode.

37. The method of any of claims 31 to 36, wherein the modulating step is performed by a control unit comprising at least one of a microcontroller (pC) , a central processing unit (CPU) , and / or a field-programmable gate array (FPGA) .38 . The method of any of claims 31 to 37 , wherein the modulating further comprises controlling of duration of application of the DC voltage and / or DC energy to be supplied by the electrosurgical generator .39 . The method of any of claims 31 to 38 , wherein the DC voltage is set to be a low voltage up to 20 Volt , preferably up to 10 Volt and in particular at least 5 Volt , and / or for DC current in the range up to 200 mA, preferably up to 80 mA and in particular at least 2 mA.40 . The method of any of claims 31 to 39 , further comprising selecting between a non-sticking mode and a sticking mode of operation using a user interface .41 . The method of any of claims 31 to 40 , further employing an anti-sticking function, preferably by controlling DC voltage and polarity, further preferably by reversing polarity, such that a single and / or series of DC voltage spikes and / or polarity reversals are issued for loosening of sticked tissue and / or preventing tissue from sticking .42 . The method of any of claims 31 to 41 , wherein said antisticking function is activated manually or automatically, preferably upon automatic directly or indirectly detecting of sticked tissue .43 . The method of any of claims 31 to 42 , wherein the electrosurgical method is performed using a monopolar application .44 . The method of any of claims 31 to 43 , wherein the electrosurgical method is performed using a bipolar application .

45. The method of any of claims 31 to 44, wherein the elec- trosurgical method is combined with high frequency in the ultrasound (US) range.

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