ELECTROSURGICAL UNI TROSURGICAL UNIT
Contents
1. The ESU developed by Cushing and Bovie was a spark gap unit that consisted of two small metal conducting pieces separated by an air gap It worked like the familiar automobile spark plug When voltage rises enough to jump across the air gap the air becomes ionized and functions as a conductor History 1924 Ground reference generator by Dr Harvey Cushing and Bovie 1970 solid state generator 1980 Argon Electrosurgery UNIVERSITY under penis 3 of LOL Act 1954 History Founder Dr Harvey Cushion and William Bovie UNIVERSITY Qnder schon 3 o UGC Act 05 Principle Active Electrode High Current Concentration Dispersive Electrode Low Current and Heat dissipates Current concentration or density depends on the size of the area through which the current flows Definition of Electrosurgery Electrosurgery is a simple well proven method of making surgical incisions control bleeding and destroying unwanted tissue cells by the use of a high frequency electrosurgical current Confusion Electro Cautery Unit Electro Surgical Unit Electrocautery A high amount of current is passed through the electrode and burning or coagulation is achieved Electrode for Cautery Scalpel Wire Only particular organ or tissue Is targeted It is a Direct Current DC Source Electro Surgical Unit ES doge qm x vi i D 3 jl XS2. Sparking at active electrode is a common occurrence There is no guarantee for where the current flows or where other tissue being affected UNIVERSITY edger RE 3 of LH Act 198568 Spark Gap Generator gh mmm em mmm m m 1 mcum a i He 63 LIP Solid State Oscillator E d d 4 x J 4 x d sald state oscillator 3 Circuit aiu lation Wave ms General Block Diagram ALES M IM Tone ea 1 RF Output Foot Switch Patient Return Electrode 65 LINE PSI ry ud E Y Lh EXT Power Supply The power supply generates the supply of 5VDC VDC 15VDC 15VDC 24VDC which is supplied to all units It is basically like a low voltage power supply The 5VDC are used for the front panel control and Display It also monitors the generated voltage for diagnostic purpose to measure the current drawn from power supply LN 1 1 LZ 4 E E 1 i 8 i j 3 1 3 1 4 E x E 1 F 4 a j E UNIVERSITY Power Supply RF output Board It has a power amplifier assembly which comprises with Bipolar M 05000131 CUT COAG and BLEND waveform The output circuit is fully isolated It generates the out put as per front panel instruction given to M ain Board and Logic Control Board Power Supply e t generates the Switch mode pulse pattern generator Drive circuit for output switching pow
3. ELECTROSURGICAL UNIT Contents Introduction Principle of ESU Application Types of ESU Techniques of ESU Operation Safety Maintenance amp Performance checkup Troubleshooting Introduction amp History Cautry S gt ica Surg Electricity Electricity is the fundamental phenomenon in nature seen in the attractions and repulsions of oppositely charged objects and utilized as a source of energy ion the form of a current Properties of electricity Electricity which moves at nearly the speed of light will 1 always follow the path of least resistance 2 Always seeks the closed path Current Current is the movement of an electrical charge electrons or ions through a circuit It is measured in Ampere There are two types of current Alternating current AC Direct Current DC Impedance Resistance tis the opposition to the flow of current tis measured in Ohms o During Electrosurgery the patient acts as impedance Voltage Voltage is the force that causes a current to flow in an electrical circuit e itis measured in volts Power Power is the rate at which energy is supplied The energy is measured in watts W Power Voltage x Current P VI History 1875 Electric current was passed through wire loop until they were red hot and heat was transferred to tissue by contact with the red hot wire
4. Front panel also interfaces with Display Board and Power Supply Board The Power Supply Switch supplies the AC mains current to the Electrosurgical Unit Display Board It is located in the Front Panel Assembly It contains RF indicator lamp Seven segment LED Monopolar Bipolar mode of surgery The RF indicator lamps are used for visual indication of presence of RF power during activation The improper attachment of Patient Return Electrode is visually indicated by Patient Return LED It also contains LED driver circuit and Seven Segment Display which indicates the Bipolar Monopolar Cut Coagulation power settings UN IV ERSITY e Audio Tone Generator lt receives the command from Main board which activates the Audio oscillator circuit Audio circuitry gets ON at time of activation of high frequency any malfunction or Fault of ESU Improper or loose attachment of patient Return Electrode and Power up It activates with signals provided by micro controller and gives high and low tone Isolation Board he patient interface board is interfaced with the M ain Board It has several different functions which is concerned with patient connected parts and provides the patient isolation voltage t monitors the patient plate continuity plate voltage BIPOLAR forceps switch CUT BLEND and COAG finger switches and patient earth monitor t monitors the high frequency leakage current This bo
5. to produce the heat 46 Blend Waveform t is a combining characteristics of cutting and coagulation waveform that results in cutting with moderate hemostasis 50 ON amp OFF 40 ON amp 60 OFF 25 ON amp 75 OFF BLEND 1 BLEND 3 47 Impact of Tissue In addition to waveform and power setting other variables impact tissue effect They Include Size of the electrode The smaller the electrode the higher the current concentration Consequently the Same tissue effect can be achieved with a smaller electrode even though the power setting Is reduced Time At any given setting if ESU is activated for longer time more heat Is produced This heat can be dispersed to the adjacent tissue Power Settings The power settings for various procedures varies from one user to another as different surgical techniques are used with different electrodes Monopolar Low Power Oral surgery Dermatology Polypectomy Plastic surgery Neurosurgery Vasectomies Hand surgery 49 Power Settings Medium Power Orthopedic surgery Normal thoracic General surgery Head neck ENT surgery Vascular surgery Transurethral resections using fine loops High Power Dale resections using ball ends and thicker oops Thoracotomies for heavy coagulation Power Settings Bipolar MICRO BIPOLAR up to 15 watts output Low Power Eye surger
6. Fi UNIVERSITY A high frequency Current flows through active electrode Cell ruptured fumes or evaporates Return path through Dispersive Electrode Patient is included in circuit Direct and Alternating Current Direct Current Electrocautery Altennating Current Electrosurgery Effect of RF current on Cell When a high frequency current is applied to the tissues the tissue gets torn apart and gets the following effects Thermal Effect Electrolytic Effect and Faradic Effect Application Electrocautery is used in surgery to burn unwanted or harmful tissue Also used to stop hemorrhage Widely used in Operation Room to perform surgical operation on patient Most suitable for delicate Neurosurgery Plastic Surgery and Ophthalmic Surgery Application To remove small lesions moles fungus bacteria hair follicles Ophthalmic Neurology ENT To stop Nose Bleeding Gynecology Dermatology Laparoscopy and Trans Urethral resection of Prostate TURP Organs Liver Spleen Thyroid Lungs and Heart Surgery Operating Frequency The frequency of operation of solid state surgical diathermy machine is 300KHz 3M Hz Ex Load of 5000 output 400W i e about 2000 Volt in cutting mode and 150 W in Coagulation mode Types of ESU Spark Gap Generator Transistor circuits Vacuum Tubes Less safety for handling Solid State Generator Transistor B
7. ard passes the Active electrode signals to main board and continuously monitors the patient plate continuity If any break occurs in plate lead or not plugged IN the related signal activates and passes to main board to generate audible signal Safety E Safety High Frequency Sometimes referred to as radio frequency or M surgery can result in serious injuries to patient if carelessly or incorrectly applied HF surgical instrument should be used on patient exclusively by personnel familiar with feature and operation of the equipment In order to prevent accidental injuries due to fault failure to equipment or its accessories the equipment and its accessories should be regularly checked for proper and safe operation Electrodes and cables are to fasten carefully Safety Hazardous electrical out put Electrosurgical unit is recommended to use only by qualified medical personnel To avoid burns do not touch active electrodes Do not operate in explosive atmosphere To avoid explosion do not operate unit in an explosive atmosphere Prevent Electrosurgery use in the presence of flammable gases flammable liquids or flammable objects Electrical Safety UNIV Electrosurgical units may cause interference with improperly shielded medical equipment Use proper power cord Use only a power cord in a good condition with properly grounded receptacle Use the proper fuses To avoid fire haz
8. ard use only fuses of correct type voltage rating and Zu rating as specified Remove the power cord during replacement of use Do not touch the active electrode to grounded metal parts or to the patient plate for function proving The cables to HF electrodes should be as short as possible and must be arranged without loops so that they touch neither the patient nor other cables Only cables recommended by the manufacturer should be used Foot switches used in explosion hazard areas must be explosion proof Patient Safety Ensure that there is no air gap between patient s body and patient return electrode Ensure that no small surface area contact is made between the patient and any of the metal parts of the treatment chair table Saline water stand which conduct ground potential Heat may be generated at such points leading to undesired burns The patient plate shall be reliable in good contact with the patient s skin for the whole operation If patient plate is fastened at limbs Be careful that it doesn t affect the supply of blood 79 ZE S T3 Cem S KS a XS X 3 oo UNIVERSITY Patient Safety The return path of the HF current shall be as short as possible and in longitudinal or diagonal direction of the body It should not go transversely through the body especially at the thorax The patient with pacemaker should be treated and consulted through cardiology department as the high frequency m
9. ased Amplifier Oscillator Circuit Modified waveform Blend Waveform High safety Grounded ESU Older generation No Return Electrode causes patient skin burn Electrode placement ECG Electrodes have least resistance to ground so site burn at electrode placement under adia 3 of UGC Act 1958 24 Grounded ESU Current seeks shortest return path to ground so by bed side monitor operating table or any conductive path Alternate site burns related to current taking pathway of least resistance to ground Patient return electrode site burns Insulation failure injuries Capacitive coupling injuries Isolated System Return Electrode introduced in solid state generator Advantage No possibility of patient skin burn Detects for return electrode attachment Measures patients impedance Recent Technology Tissue Response Technology t uses a computer controlled tissue feedback system that senses tissue impedance resistance and automatically adjusts the current and output voltage to maintain a consistent surgical effect Advantage Reduces the need to adjust power settings for different types of tissue It also gives improved performance at lower power settings and voltages which helps to reduce the risk of patient injury Le Argon Argon Enhanced Technology Argon Gas in Electrosurgery Argon Gas Properties Inert Gas Non
10. ay affect or damage to the pacemaker Outpatient with pacemakers should not be treated using a HF generator Avoids skin to skin contact such as fingers touching the patient s leg when ESU is activated F d T E E 3 E E j Be E 3 d 3 1 d d E E 1 s 5 F X 3 1 d f E 1 jd 1 ei UNIVERSITY Patient return Electrode safety precautions Discard the disposable packages that have expired Use Patient Return Electrode according to the manufacturer s documented instruction Inspect patient return electrode before each use for wire breakage or fraying Select appropriate size patient return electrode for patient i e neonate infant pediatric adult Do not cut patient return electrode to accommodate patient Size Shave clean and dry at application site as needed UNIVERSITY 5 Patient return Electrode safety precautions Place patient return electrode on positioned patient on a clean dry skin convex area in close proximity to operative site Avoid bony scar tissue skin over an implanted metal prosthesis hairy surfaces pressure points tissue and areas where fluid may pool Apply finger pressure to adhesive border of the electrode and massages entire pad area to ensure adequate contact with the patient s skin L JN IVERSITY Patient return Electrode safety precautions Follows manufacturers guidelines for alarm system check prior to use Check
11. combustible Easily ionizes Displays the blood to visualize surgical site Less smoke t produces a beam like manner and creates bridge between electrode and tissue 28 M odes of Electrosurgery CC M onopolar Surgery CC Bipolar Surgery M onopolar Surgery RF current flows through ESU and Active Electrode Returns to ESU through Return Electrode Used for cut and coagulation Bipolar Electrosurgery Output current flows via BIPOLAR electrode in one terminal Returns the current through another terminal It is much safer than Monopolar surgery Used for cut and coagulation too 31 Advantages of Bipolar It is much safer than M onopolar RF current flows only through well defined area while in Monopolar current flows back through large section of patient body Risk of patient touch is low Less Interference for other instruments No patient plate or Return electrode is required Electrode There are two types of Electrodes used in Electrosurgery L Active Electrode 2 Dispersive Electrode Active electrode There are two types of Active Electrode Cutting Electrode Coagulation Electrode SRM UNIVERSITY Cutting Electrode Cutting Electrode They are available in different shapes Angulated Needle or wire loop shape Wire Loop Electrode Angulated Electrode Cutting Electrode Angulated C
12. e to activate any audible signals Labeling Check for necessary labels and instruction cards are present Dispersive Electrode cable continuity Check the patient return electrode continuity and any alarm functioning on removal Accessories Footswitch To check the physical integrity connection and proper operation of all accessories related to ESU Safety Test Procedure Switch on the safety analyzer and connect the Test lead between ENCL and EARTH Press set up in the main menu Press CAL in the system set up Press Calibrate Test Lead Enclosure Ground The test results are displayed once the Calibration is complete Connect the Main Plug of the Electrosurgical Unit ESU to the Safety Analyzer Terminal on the front panel G SRM UNIVERSITY Safety Test Procedure e Connect the calibrated Test lead between ENCL on the Safety Analyser Terminal to the Chassis or the ground terminal of the Electrosurgical Unit ESU e Ensure that the main switch on the Electrosurgical Unit ESU is switched ON Inthe main menu press Equipment Code and enter the Asset number of the ESU Press Equipment Classification and select classification Press Start in the main menu to start the test e Once the Electrical Safety Test is over print the test result amp SRN UNIVERSITY Quantitative Test Connect the Electrosurgical Unit to the Electrosurgical Analyzer and verify output power g
13. ease in the power setting e Accidentally if any part of the patient body touches to ground a burn effect Will occur at that site Ideally the arms or muscular abdomen can be a suitable site for placement of patient return electrode L Ca i i s d 3 3 E i d d a i E L j d j 4 B i iy 5990 UNIVERSITY M odes of Electrosurgery Electrotomy Cutting Tissue gets heated and tissue ce explodes in to a steam When the new tissue come under contact it tears apart and incision takes place 42 Electrotomy Cutting The RF current applied to the tio of Electrode e The cutting waveform has 100 Duty Cycle TTT NAA PURE CUT UNIVERSITY aS Desiccation Coagulation e In this mode needle or ball electrode Is Kept steady inside the tissue When RF current flows through the tissue cell it becomes hot and water evaporates slowly so cell plasma gets coagulated COAG Desiccation Coagulation Coagulation By Needle Electrode or Ball Electrode can be achieved Factor consideration Intensity and duration of Current Fulguration finder section 3 of UDC Act 1958 There is no contact between Active Electrode and target tissue But electrode is close enough to generate the spark t Is a process of Coagulation Dehydration of cell takes place with sparks Only 6 of duty cycle is used
14. enerated by ESU Procedure to check Output Power up the Electrosurgical Analyzer and wait for self test to pass Attach the Monopolar Electrode and patient return electrode to the ESU Connect and hold Active electrode with crocodile pin to the Electrosurgical analyzer Jack similarly connect the patient return electrode Put ON the ESU analyzer and wait for self test to pass Once the Main display appears select the particular load e g 500 Put ONT the ESU and wait to complete the self test T N it A ITY 7 Quantitative Test ENEE Select CUT mode and minimum power out put energy on M onopolar by pressing UP and DOWN arrow key Press the Hand switch or foot switch to get the output Note the audible sound and measured power output Selected Output on ESU and Displayed output on ESU analyzer should be same or with in range of tolerance Select the different power and note down the readings If it differs refer service manual for calibration Similarly check for COAG mode Check for Bipolar mode Troubleshooting Servicing Techniques Service M anual Guess or Judge Step by step procedure to troubleshoot UNIVERSITY i 1 1 CH Be E 1 1 1 3 i 5 j gt c Troubleshooting anco USER CHECKLIST e Check the Electrosurgical Unit ESU for physical damage Verify all accessories cords are connected properly Check the co
15. er M OSFETS and High Frequency filtering components n enhanced type generator the output power Is managed and controlled according to patient s tissue impedance Memory Board The function of this board is to accept operating mode control signal from front panel rear panel and foot switch t checks and identifies that which connector Is in use and monitors its continuity interfaced Front Panel switch signals decode and passes Information to Display Memory Board t has a microprocessor used together with EPROM as program memory and RAM The analog to digital conversion of signal to convert the commands received from front panel and fed to logic board t also generates the audible command whenever any fault occurs during self test and operation It detects all front panel operation and acts as per instruction nekr 3 of LOC Act E Logic Board Relay Board he board is mainly interfaced with Main Board or sometimes all functions of M ain Board are incorporated It iS a liaison between front panel and output required All signals are inter related to this board t gives the power output command to RF or Power output board and monitors the output It has relay board too which activates according to finger switch or foot switch control o Front Panel It consists of membrane keyboard Power switch Patient Return Electrode M onopolar Bipolar connector
16. k AC power plug for damage Attempt to wiggle the blades to check that they are secure Shake the plug for loose screws If any damage Is suspected open the plug and inspect it Check the fuse and fitting position Line Cord Inspect the cord for damage amp excessive bending If damaged replace the entire cord Verify the minimum power cord length before cutting the defective position Strain ke Examine the strain relief at both ends of the line cord Be sure that they hold the cord securely Circuit Breaker Fuse If the device has an external circuit breaker check that it operates freely If the device is protected by an external fuse check its value and type against that marked on the chassis and ensure that a spare Is provided 2 SH RIV UN IVERSITY Preventative M aintenance Connectors Examine all cables of the ESU for proper fittings and firm contact of connectors Probes Confirm that probes for their physical condition For disposable probes check expiry date Controls Switches Examine all controls and switches for physical condition secure mounting and correct motion Look for loose connections Check for proper alignment as well as positive stopping Confirm the functioning of each switch and controls proper functioning Indicators Displays Confirm the operation of all indicators on the unit that all segments of a digital display function and functioning of Alarms Audible Signal Operate the devic
17. ndition of power cord it should not be frayed damaged crack or exposed of any wire otherwise replace the same immediately Check the fuse of ESU It should be firmly fitted inside the fuse socket Also check for any corrosion and damages If so replace the same rating of fuse as mentioned in manual and on ESU UNIVERSITY Troubleshooting Disconnect the power cord and check for Footswitch receptacle damage or obstruction If found replace the rear panel or rear panel connector Check for the firm contact of Bipolar Instrument receptacle on front panel for obstruction and damage If found replace the front panel or front panel connector Check for the firm contact of M onopolar instrument receptacle on front panel for any obstruction and damage If found replace the front panel or front panel connector e Check the patient return electrode receptacle for any broken pins and obstruction If found replace the front panel or front panel connector
18. o pin connector to attach patient return electrode in Monopolar procedure Bipolar Receptacle It accepts three pin receptacle for bipolar electrode This will activate with and without footswitch Rear Panel e Foot Switch Receptacle It accepts monopolar footswitch connector Audio volume Control The tone volume can be adjusted for Cut Coag and Bipolar mode Equipotential Lug It may be connected to earth ground with a cable Operation Visual Inspection Check continuity and condition of power cable plugs and Accessories cable Check for any crack insulation break frayed cable Generator tone should be at an audible level Check instrument for proper functioning before operation Functional Test Attach footswitch to rear panel or to the ESU receptacle end Attach Power Cord to AC plug Put ON the main switch of ESU Wait for self test to pass Connect M onopolar Bipolar Electrode and cable to respective connector Switch ON the High Frequency by means of pressing footswitch or handle switch Increase the Energy Level and look for audible sound and visual light indicator Confirm all the time lowest power setting and confirm with surgeon 61 Keep in mind Always prefer lowest power setting and confirm with surgeon Doattend for checking audible and visual signal Patient Return Electrode is not required for Bipolar mode
19. patient return electrode connections to confirm that they are clean intact and can make effective contact Remove patient return electrode gently to protect skin amp SRM UNIVERSITY Active Electrode safety precautions e Avoid coiling bundling or clamping of active and patient return electrodes Avoid wrapping the active electrode cord around a metal Instrument Remove all metal patient jewelry to prevent current diversion and to avoid contact with other metals Place active electrodes in a non conductive holster designed to hold electrosurgical pencils and similar accessories when they are not In use UNIVERSITY Active Electrode safety precautions Activate electrode mode and function Keep active electrode free from debris Record placement of patient return electrode identification number of unit and settings used Inspect insulation on reusable and disposable electrodes before and after use NK oF am my 5 UNIVERSITY Preventative M aintenance Chassis Housing Check Exterior of unit for cleanliness and general physical condition Be sure that plastic e intact that all hardware Is present and fitting are firm and tight and that there are no signs of spilled liquids Mount Fasteners If the device is mounted on a stand or cart examine the condition of the mount If it Is attached to a wall or rests on a shelf check the security of this attachment AC Plug ode circ Chec
20. utting Electrode Wire Loop i i uu n 1 7 r 5 j Se 1 b i F ij l E E S 1 E 4 E 9 3 4 05 1 Si E UNIVERSITY Coagulation Electrode These are available in the blunt shape ball shape or Bipolar type The density area of this electrode is bit larger than cutting electrode Bipolar Electrode Ball Type Electrode Bipolar Electrode Straight bh Ball Type Electrode AT i E K 1 3 1 5 3 d E 3 E 3 1 3 ir P sail d a j T 4 UNIVERSITY Dispersive Passive Electrode e It is also called as or J Patient return electrodes remove electrical current from the patient by completing the patient generator circuit Dispersive Passive Electrode Lead Metal plate wrapped in wet cloth bag Disposable Type Electrode Area should be larger than active electrode about more than 100cm Single Contact Surface Double Contact Surface Placement and area of affect The patient becomes the part of electronic circuit As the current seeks for shortest and less resistive path to ground user should be aware that position of patient return electrode should be as shorter as possible T VERSI Dnr sectas 3 of UGC Act 1958 Placement and area of affect If a return electrode is placed far from the operating task the current has to travel a long distance resulting incr
21. y Fine neurosurgery Medium Power Neurosurgery Fine plastic surgery High Power Hand surgery Plastic surgery o1 Power Settings M ACRO BIPOLAR up to 50 watts output Low Power Hand surgery Plastic surgery Medium Power General surgery High Power Orthopedic surgery UN IVERSITY Operation Fe e finder section 3 of UGC Act 1956 Front Panel e On Off Switch To switch ON and Off the ESU e Coag Dial Clock wise rotation of dial to increase the output gradually 04 pear section 3 of OC Act 1908 Front Panel CUT Dial To increase the current density to cut a tissue e Pure Blend Selector Switch or key to select the type of cutting current either PURE for minimum hemostasis or BLEND for average hemostasis while cutting 55 Indicator e COAG Mode Indicator illuminates blue when activating the output CUT Mode Indicator illuminates yellow when CUTTING Pure or Blend is selected Patient Return Electrode fault Indicator for poor patient contact alarm Front Panel Monopolar Receptacle It will accept three pin hand switch forcep Only hand switch mechanism will work Monopolar Receptacle Standard receptacle for accessories It will activate only if footswitch is connected Front Panel Patient Return Electrode Receptacle The tw
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