low / medium power electrosurgery review 2002 · electrosurgery (surgical diathermy) is a commonly...

NUMBER

02037

Cutting

Low / Medium Power ElectrosurgeryReview 2002

Contact Coagulation

Loop Excision Spray Coagulation

Introduction and Modalities

MDA evaluation 02037, March 2002 2

INTRODUCTION

Electrosurgery (surgical diathermy) is acommonly used surgical tool but the method ispoorly understood. Electrosurgery is increasinglybeing used for a variety of outpatient and minimalinvasive surgical procedures. In addition, somelow powered units are purchased for performingminor surgical procedures in the GP surgery.

Low and medium power output monopolarelectrosurgical units (ESUs) are reviewed in thisevaluation report. Bipolar mode is available ontwelve of these models but there are also a numberof dedicated bipolar ESUs on the market whichwere reported on in evaluation report 01022 (seethe back page for how you can obtain a copy). Afurther review will be published next yearcovering high powered ESUs available in the UK.

Most low/medium powered ESUs have beendeveloped for specific specialties and operativeprocedures. In addition, electronic designimprovements have enabled three manufacturersto produce ESUs suitable for general surgery

applications, including urology, without requiringhigh power output settings (over 200 Watts).

This report includes a brief introduction to theelectrosurgical technique, a guide to sometechnical and procurement issues in addition to theproduct data pages. Fifteen electrosurgery unitshaving power outputs up to 200 Watts are brieflysummarised. Brief technical assessments wereconducted on fourteen devices specifically for thisevaluation report. A summary of manufacturer’sdata on the Ellman Surgitron Dual Frequency isincluded for completeness.

A glossary of electrosurgery terminology iscontained in the Appendix at the back of the report.

ELECTROSURGICAL TECHNIQUE

Tissue Heating: Using heat to stop bleeding(cautery) is an ancient technique whichtraditionally used hot metal objects. If theapplicator is heated electrically this is calledelectrocautery. Tissue damage is largelydependent on the temperature achieved (Table 1)and heat transfer by conduction. Cautery ishindered by unpredictable tissue damage.

Table 1 Tissue temperature vs surgical effect

>40°C Reversible cell damage

>49°C Denaturation (irreversible celldamage)

>70°C Coagulation (collagens convert togelatin)

>100°C Desiccation (cells dry as watervaporises, gelatin becomes ‘sticky’)

>200°C Carbonisation , eschar formation(pathological 4th degree burns)

In electrosurgery / surgical diathermy the electriccurrent (I) is designed to travel through tissuebetween metal electrodes, producing heat in thetissue while the applicators remain relatively cool.The resistance (R) or impedance of tissue to theflow of electricity generates heat within cells,intracellular fluid and blood. Mathematically, localheating (Watts) is proportional to I × I × R.

Electrosurgery uses high frequency oscillations,usually between 200kHz and 5MHz, to achievetissue heating. High frequencies avoid musclespasms and cardiac fibrillation that is caused byinadvertent contact with frequencies below100kHz, for example mains electricity at 50 Hz.

CONTENTS Page

Introduction 2Electrosurgical Technique 2Design Features 5Guide to Product Data Pages 9Procurement Issues 11Product Summaries

Aaron Bovie 1250 12Aaron Bovie 2100 13Conmed Hyfrecator 14Ellman Surgitron Dual Frequency 15

Ellman Surgitron Radiolase 16ERBE ICC 50 17ERBE ICC 80 18ERBE ICC 200 19Korpo Timed TD50 20Martin MD 62 21Martin ME 102 22Martin ME 200 23Olympus PSD30 24Utah Medical Finesse 25Valleylab Surgistat II 26

AppendixGlossary of Terms 27Additional Information 28


MDA evaluation 02037, March 20023

Figure 1 Bipolar Electrosurgery

Bipolar Circuit: In bipolar electrosurgery twoelectrodes are combined into a single applicator,usually forming forceps. Only the tissue graspedbetween the two tines of the forceps are includedin the electrical circuit (see Figure 1).

Figure 2 Monopolar Electrosurgery

Monopolar Circuit: The monopolar circuit onlyuses one electrode (active) at the surgical site anda separate electrode (return) is placed somewhereelse on the patient’s body. The electrical currentmust pass through much of the patient’s body tocomplete the circuit (see Figure 2). Monopolar isthe more commonly used electrosurgical modality,due to its versatility and established clinicaleffectiveness, but it is known to involve greaterrisks to patients and staff than bipolar coagulation.

Controlling the surgical effect: High frequencycurrent has either a coagulating or cutting effectaccording to the shape and dimensions of theactive electrodes, the chosen electrosurgical mode(voltage waveform) and the output power.

Tissue changes as a result of this energydeposition primarily depend on the current

density. If the current is highly concentrated, forexample when a thin wire barely touches the tissuesurface, then all the energy is deposited in a veryfew cells, producing very high temperatures sothey vaporise. This causes the tissue to split asthough it had been cut with a razor sharp knife, asshown in the top left figure on the front cover. Asa result a fine electrosurgical cut can be a producedby stroking a fine wire along the tissue surface inmonopolar mode. Using a larger electrodeproduces a lower current density and a lower risein temperature so contact coagulation of the tissueis more likely, as shown in the top right figure onthe front cover.

There is a wide range of types, shapes and sizes ofactive electrodes. The nature of tissue modificationis heavily dependant on the type of electrode used,with a fine needle electrode producing a cut usingthe same current that would produce contactcoagulation from a large area ball electrode. Forexample, when the Korpo Timed TD50A is in theCoag Micro Elect mode a fine needle will cuttissue if the power exceeds 14 Watts. Conversely alarge electrode and low power can producecoagulation even when the cut mode has beenselected, but the surgical result is unpredictable.

To complicate matters the actual power output israrely constant. Characteristics vary betweendifferent designs of ESU, as illustrated by thepower curves on pages 8&9, which are alsopublished in User Manuals. The actual poweroutput is affected by the load impedance, primarilydetermined by the tissue type at the surgical site.However other factors (eg poor skin adhesion andelectrical contact of the return electrode, excessivedistance between the surgical site and the returnplate electrode, damaged accessories) also increasethe overall impedance to electrosurgical currentflow and may reduce the surgical effect.

Power curves of many ESUs show a peak in thepower output at specific impedance values.Frequent adjustment of the power setting will berequired to achieve a consistent surgical effect fordifferent tissues. Power curves of some ESUs canmaintain almost constant power output regardlessof the local tissue impedance, whether it is muscle(500-1800Ω) or fat and scar tissue (above 3000Ω).

Fatty tissue, air and bone have low water contentso are highly resistant to the flow of electrons.Consequently a high voltage is required to ‘push’electrons through these tissues or across an air gap.When an active electrode is held over muscle the

active lead

ESUreturnelectrode

bipolar lead

ESU



electrosurgical current flows easily, as blood is agood conductor and a low voltage is required. It isgood practice to experiment on samples ofdifferent meats from a butcher until the user isfamiliar with the characteristics of each ESU andactivation mode.

Ideally the electrodes should remain cool andseparable from the tissue while they deliver theelectrosurgical current. However this requirescareful selection of the power setting and surgicaltechnique to ensure the power is switched offimmediately the tissue is blanched. Furtherheating converts collagen into gelatin, which athigher temperatures becomes sticky and then ablackened eschar (see Table 1 on page 2). Tissuemay then remain attached to the active electrodeand cause rebleeding following its removal.

MODALITIES

Each manufacturer uses their own terms todescribe the activation modes of their generator.The most common terms are: cut, blend, contactcoagulation (or desiccation) and spray coagulation(or fulguration).

CUTTING: Cut waveforms are continuous AC, butthe shape varies between manufacturer and model,some using sinusoidal, square wave, etc. Cuttingvoltages must be above a few hundred volts todevelop the arc (or spark) required for cutting butmust be low enough to avoid unwanted charring.When electrosurgical cutting is performed withthe correct technique it is atraumatic and reducespost-operative problems such as tissue swelling,post-surgical shock and contractile scar tissue.

Bipolar Cutting & Ablation: New types ofaccessories and specialised bipolar electrosurgicalunits have been developed to make cutting andablation possible. This issue is covered in moredetail in the Bipolar Review (evaluation report01022). Bipolar electrosurgery cutting may beconsidered for operating on a tissue pedicle, suchas a penis, but it is important to consult the ESUuser manual and/or manufacturer for guidance.

Monopolar Cutting: The monopolar modality ismore versatile and widely used. Effective surgicalcutting is best achieved with a fine wire, ensuringthe tip hovers above the incision site with asmooth brush-stroke, so it does not adhere to thetissue. Cells close to the tip of the active electrodeburst when the cellular water is heated rapidlyand boils. (see top left figure on the front page)

Monopolar cutting should not be used when aconstriction in soft tissue can occur between theoperative site and return electrode. A concentrationof electrosurgical current in the return path throughthe tissue constriction (pedicle) can causeunwanted damage from tissue heating.

Yellow colour coding is usual on dials, switchesand indicators for activating monopolar cut.

BLEND: Monopolar blend waveforms have acontinuous waveform that is modulated to giveresting periods. This allows heat to spread intoadjacent tissues causing cutting with somecoagulation of the cut surface. Some devices offerseveral blend modes giving variable coagulationdepths. The degree of haemostatis is regulated bythe blend waveform shape not the ratio of cut tocoag power output settings. Blend may be calledCUT/COAG by some ESU manufacturers.

When electrosurgical cutting is performed withminimal but sufficient haemostatis of the cutsurface it reduces post-operative problems such aspost-surgical shock from excessive blood loss, andpost operative adhesions.

Yellow colour coded dials, switches and indicatorsare usual for functions associated with blend.

COAGULATION: Spray coagulation waveformsare short duration, high voltage pulses, thattypically require a few thousand Volts, to sparkacross the air gap between the active electrode andtissue surface. By contrast, contact coagulationwaveforms have variable characteristics.Depending on ESU manufacturer and model thewaveform may be pulsed or continuous but it willhave a higher crest factor than the cuttingwaveform.

Blue colour coding is usually used for functionsassociated with coagulation.

Bipolar Forceps Coagulation: Small tissuebundles and blood vessels can be coagulated withbipolar electrosurgery. The blood vessel or tissueis grasped between the forceps tines, each of whichacts as an active electrode, and current passes todesiccate and coagulate the tissue. Powerrequirements must be matched to the size andshape of the accessories and impedance of thetissue volume held between the forceps tines.

Providing there is no loss of surgical performancethe bipolar mode may be preferred for forcepscoagulation where risks are significantly reduced,

Design Features


compared with ‘buzzing the haemostat’ or usingmonopolar forceps. Current flow is limited to thesmall tissue region between the tines (activeelectrodes). This results in more predictable tissuemodification with less risk of neuromuscularstimulation. Return electrode burns are eliminatedand the potential for alternate site burns orinterference with electronic devices is reduced.

Contact Coagulation (Monopolar): Contactcoagulation is less dependent on the waveformthan on the method of application. A large contactarea will result in tissue coagulation, as the currentdensity is low (see top right figure on the frontpage). Activation should stop immediatelyvaporisation occurs, ie when the tissue blanches,so the electrode remains cool and separable fromthe tissue. This will minimise necrosis, tissuetearing, rebleeding, regular cleaning of the activeelectrode and the smell of burning flesh.Surprisingly, lowering the power setting increasescoagulation depth as the extended application timeto achieve surface blanching enables heatconduction to deeper structures.

Contact coagulation may also be calleddesiccation, ‘hemo’, pinpoint, ‘soft coag’, ‘forcedcoag’ or ‘LO’ by some ESU manufacturers.

Spray Coagulation (Monopolar): Spraycoagulation is a non-contact coagulation techniquealso called fulguration or ‘HI’ on some ESUs.Using a high voltage to spark to the tissue from anelectrode held away from the surface, results insurface charring and coagulation (see bottom rightfigure on the front page). Removing surfacemoisture before activation ensures the open end ofsmall bleeding vessels have lower tissueimpedance and attract the sparks, so the heatingseals the vessel ends. This technique rapidly sealsorgans with a large number of small blood vessels,such as liver, but produces copious smoke andfumes as a black eschar forms on the surface.

Particular care is required while using very highvoltages as this carries the highest risk ofinadvertent tissue damage, especially forminimally invasive techniques. High voltages aremost likely to cause a breakdown in the insulationcovering the electrosurgical leads and electrodes,leading to arcing and burns in adjacent tissues,alcohol based ‘prep’ fluids, surgical drapes, andpossibly the surgical team. Earth leakage(capacitive coupling) currents are also greater athigh voltages.

DESIGN FEATURES

This section provides a brief description of designfeatures mentioned in the product data pages.Some of these are specific to a singlemanufacturer. Please note inclusion in this sectionshould not be interpreted as endorsement of thedesign feature.

Low and Medium Power Electrosurgery unitsincluded in this review vary considerably in theirsophistication. The simplest provide onlymonopolar output with single cut and coagulationmode. However, many ESUs provide bipolar andmonopolar outputs and a wide range of differentmodes to achieve various tissue effects. Therequired tissue effect is obtained by a carefulselection of appropriate accessories, output mode,power level and surgical technique. These factorsvary from device to device and more detailedinformation may be found in the user and servicemanuals for each device. Some manufacturers alsooffer supplementary written, audio-visual or CD-ROM training information prepared by clinicalusers familiar with the specific unit.

Electric Shock Protection: Careful ESU designmust limit the leakage of mains frequency (50Hz)electric current to electrodes touching the patient.All ESUs in this report are mains powered andconstructed to Class II requirements, ie they havedouble or reinforced insulation for wires carryingmains frequency current. Medical equipment isclassified by the level of patient protection frommains leakage current. Applied parts electricallyisolated from earth and with low leakage currentsare classed as F-type (F for floating). Leakagecurrent protection is further classified as type B orC. ESUs in this report are either classified as BF,indicating they are suitable for direct patientcontact providing cardiac tissue is avoided, or typeCF, ie suitable for direct cardiac application.

Rf-Isolated: Many ESUs are also electricallyisolated at high frequencies. Rf-isolation reducesthe risk of current leakage to earth or alternate siteburns, should the patient touch an earthed metalobject or if the return electrode connection shouldfail. Patient safety can be compromised when amixture of isolated and earthed equipment isattached. It is also important to be aware that somemains isolated patient monitoring equipment maynot be well isolated at high frequencies.

Earth Referenced: Four lower powered units (upto 50 Watts) included in the review are earth

Design Features


referenced at high frequencies. Manufacturersmay suggest using capacitive coupling of theESU current to earthed metal objects, such as adentist’s chair, to return monopolar electrosurgicalcurrent to the ESU. However, great care should betaken when a conductive patient return plate is notattached.

Duty Cycle: All low/medium powered ESUsspecify the type of activation tolerated for an hourwithout overheating of electronic circuitry andadversely affecting the power output levels. Oneach Product Data Page the duty cycle is stated,specifying the activation time, ‘on time’, andpause required between surgical activation, ‘offtime’. The design of some ESUs enablescontinuous activation at full power without theunit overheating.

Programmable Cut/Blend Waveforms: TwoESUs developed for specialist applicationsprovide the option of pre-programmed delivery ofpulses of specified duration and/or separation onactivation

Fractionated delivery for cutting ‘underwater’ inglycine solutions has been called ENDOCUT. Amoderately high voltage cutting waveform isgenerated to heat the solution and produce an arcin the water vapour. When this moment isdetected a pure cut waveform continues for a shortpre-defined period before being turned off, topermit the heat to dissipate and coagulate thetissue. Extending the ‘off time’ increases the depthof coagulation.

Another ESU permits activation time to be pre-programmed in fractions of a second and initiatedeach time the foot switch is depressed. In addition,special waveforms are programmed with the ‘ontime’ and ‘off time’ specified in hundredths of asecond. Both are designed for delicate cutting.

Specialised Contact Coagulation Modes: SomeESUs provide a monopolar coagulation modewhich produces very low power output for highload impedances. This is called ‘soft coagulation’on several ESUs included in this review. Theseunits also provide a second coagulation mode witha more conventional power curve which is called‘forced coagulation’.

Some ESUs in bipolar coagulation mode havepower curves with a shape similar to that of ‘softcoag’, eg Aaron Bovie 2100, Erbe and MartinME102 & 200. Other models maintain highpower output levels at relatively high tissue

impedances, ie Aaron Bovie 1250, ConmedHyfrecator, Korpo Timed TD50 and ValleylabSurgistat II.

Argon Beam Coagulation: Argon is an inert,non-combustible gas more easily ionised by anelectrosurgical current than air. In spraycoagulation mode a stream of argon gas flowingover the active electrode is reported to improve thesurgical effectiveness of surface coagulation. ErbeICC200 offers argon beam coagulation as anoption but this facility was not available on thedevice tested for this review.

Power Control: All ESUs provide the surgeonwith a rotating dial or digital buttons to vary poweroutput levels. Some manufacturers display thepower setting in Watts. Other manufacturersprovide a dial position setting, usually 0 - 10,roughly dividing the maximum ESU power outputin that mode, eg 50 Watts. The user manual willprovide details of the maximum power if there isno display or label on the ESU.

Great care should be taken when using differentmodels of ESU as the same dial settings may notproduce equivalent power outputs. For example apower setting of ‘5’ could produce majordifferences in surgical effect as it can mean 5Watts or, perhaps, 50 Watts (if the ESU maximumpower is 100W).

Active power/voltage management: Carefulcontrol of voltage and power output parameterswill achieve smooth cutting in most surgicalprocedures. Some electrosurgical generators havemonitoring and control systems designed tomaintain output power and/or voltage to withinpre-set limits, dependent on the mode and powersetting. These systems have various descriptionsincluding constant voltage, dynamic powerregulation, CUT CONTROL, Optisense, etc.

Active output control is particularly useful inprocedures such as loop excision in colposcopy(see bottom left figure on the front page). In thisprocedure a section of tissue is removed in onecontinuous movement of the loop; but the tissueimpedance changes as the area in contact with theelectrode starts small, increases to a maximum,then falls again.

In cut or blend modes a burst of higher voltagemay help to initiate ionisation between the activeelectrode and tissue surface. This type of activeoutput control has been called Power PeakSystem.

Design Features


Capacitive return electrodes: Some ESUmanufacturers supply capacitive return electrodesfor use with specific models. This design ofreusable return electrode provides an inexpensivealternative to the conductive, adhesive pads andmay be convenient in an outpatient clinic.However, some may be difficult to position inclose contact with the skin surface over a wellvascularised region. Because there can be nocontact quality monitoring there is an increasedrisk of alternate site burns when using capacitiveplates, particularly with earth-referenced ESUs.

Users must verify with the manufacturer thatcapacitive return electrodes supplied separatelyare compatible for use with each specific ESUmodel.

Activation Switches: All electrosurgical unitsincluded in this review can be supplied with afootswitch(s) to activate ESU power output.However care must be taken if using more thanone ESU model as there is no standard footswitchconfiguration. The Ellman Surgitron Radiolase,Korpo Timed 50A and Martin MD62 require themode (cut or coag) to be selected on the ESU frontpanel and a single footswitch is supplied foractivation.

Some ESUs in this review (from Aaron Bovie,Erbe, Olympus, Utah Medical & Valleylab) haveseparate pedal switches for activating cut andcoagulation modes which are colour coded, yellowfor cut and blend modes and blue for coagulationmodes (both monopolar and bipolar). AlthoughMartin ESUs also supply twin blue and yellowfoot switches and a separate white foot switch isprovided for activation of bipolar coagulation.

Conventionally in the operating theatre thecoagulation (blue) pedal is placed to the right ofthe cut/blend (yellow) pedal. Erbe units and theOlympus PSD-30 are supplied with pedals fixed inthis orientation and also have a central footrest.This design may avoid inadvertent selection of thewrong activation mode. Please note somefootswitch designs are prone to inadvertentactivation, eg. if they are moved or becomephysically wedged during the surgical procedure,eg under the operating table support.

Finger-switching pencil electrodes are availablefor many ESU models in this review series. Mostprovide yellow and blue buttons to active thecut/blend and coagulation respectively. TheConmed Hyfrecator permits control of the poweroutput level and an activation button on the

monopolar finger-switching pencil but the modemust be selected on the ESU front panel.

Automatic Start: In bipolar mode electricalimpedance across the ESU output suddenly dropsas tissue is grasped between the forceps tines. Insome ESUs electrosurgical output may be activatedautomatically when the forceps grasp conductivetissue. This feature can enable coagulation of alarge number of small vessels withoutsimultaneous activation of the footswitch eachtime. Some devices introduce a pause of a fewseconds between tissue contact and activation toenable the surgeon to briefly manipulate tissuewith the inactive forceps.

Automatic Switch Off: Contact coagulationshould continue long enough to ensure that vesselswill not re-bleed but should not cause excessivetissue damage (Table 1 on page 2). Heating driveswater out of cells reducing the ability of tissue totransport current and so tissue impedance rises.Auto Stop monitors the rise in impedance andturns off activation once it reaches a pre-set value.

SAFETY FEATURES

Start-up Self Check: Some low and mediumpowered ESUs perform an internal check on startup and prior to activation being permitted.

Return Electrode Continuity Monitor: Anisolated ESU will not work unless a patient returnelectrode is connected to the generator inputsocket. This is a requirement of the latest versionof the international standard for electrosurgicalunits (EN60601-2-2:2001).

Contact Quality Monitoring (CQM): Using a splitplate return electrode with two wires a smallmonitoring signal can be ‘injected’ into oneelectrode half, flow through the skin and tissue andreturn to the generator via the other electrode half.Measuring the total impedance monitors electricalconductivity across the pad-skin surface. If thisexceeds a pre-set range, eg 0-150Ω, ESU poweroutput is stopped and an alarm sounds. Returnelectrode contact quality monitoring (RECQM orCQM) reduces the risk of patient return electrodeburns. However, those units that need a largerimpedance value to trigger the alarm may be lesseffective in detecting poor pad-skin contact.

Return Current Feedback Monitor: Monitoringcurrent flow to the active electrode and comparingit with that from return electrode can detect currentdivision and prevent alternate site burns.

Design Features


High Frequency Leakage Monitor: Monitoringthe high frequency current flowing to the ESUfrom earth can detect earth leakage. If it exceeds apre-set limit ESU power output is disabled and analarm sounds. High levels of electrical coupling toearth can occur for many reasons eg. insulationfailure and poor return electrode contact.

Earth leakage connector: Some manufacturersof minimally invasive equipment incorporate anearth leakage connector (safety cord or S-cord) toprovide a direct return pathway to the ESUgenerator for rf leakage currents in the metalendoscope / laparoscope. This equipment shouldbe used with split plate electrodes and a contactquality monitoring system to prevent this leadbeing inadvertently used as the primary currentreturn path to the ESU. An S-cord continuitymonitor can ensure the S-cord is not inadvertentlydisconnected.

Output Error Monitoring: Equipmentmalfunction, overheating or incompatibility withESU accessories can cause excessive poweroutput and adversely affect surgical outcome.Some units monitor actual power output,comparing this with selected power setting. Ifoutput exceeds pre-set limits above the intendeddosage the ESU output is disabled and an alarmenacted. This feature may be called output errormonitoring by some manufacturers.

This feature is mandatory for ESUs over 50 Wattsdesigned in compliance with the latest version ofthe international standard (EN60601-2-2:2001).This document specifies the maximum allowedoutput power in single fault conditions.

Smoke Filtration: There is some evidence thattoxic and carcinogenic by-products are containedin the smoke plume and aerosol generated byelectrosurgery. Use of high filtration smokeevacuation units, simultaneously activated by theESU, is now an option for several models in thisreview. The Utah Medical Finnesse has anintegrated smoke evacuation and filter unit but thisfacility was not tested for this review.

Activation Time Limit Alarm: ESU power outputis automatically turned off after a pre-set period.This would reduce deleterious effects caused byinadvertent prolonged activation, eg ESUoverheating.

SPECIFICATIONS

Power output should be sufficient to achieve thedesired surgical effect but should not be too highsince this increases the risk of unwanted tissuedamage. Power requirements vary according to thedesired surgical effect, the active electrode size andtype of tissue to be treated. Tissue in the currentpath determines the electrical load, but this canchange as the current alters the tissue’s properties.The power output depends on this load, with theselected power level usually indicating themaximum power that may be delivered.

A useful characteristic of electrosurgical powerdelivery is the variability of power output as thetissue impedance changes for a fixed powersetting. This is called the power curve and everyESU user manual must include power curves formaximum and half power settings in each mode.Knowledge of tissue impedance values typical fora specific operation can help in the selection of themost appropriate electrosurgical device and mode.

To illustrate this concept we could consider bipolartubal sterilisation. This surgical procedure mayfail if the combination of bipolar forceps and ESUoutput parameters do not achieve completecoagulation of the inner core. Power curves canhelp to predict the tissue effect. For example twohypothetical ESUs with different characteristicsare illustrated. The power curve in Figure 3asuggests that high power output is only possible fora tissue volume of very low impedance. Tissueheating could stop immediately once superficiallayers are dessicated, as this will slightly increasetissue impedance between the bipolar tines and thepower output will drop. By using an ESU mode

Figure 3a Power curve: rated load of 50 ΩΩ

0

25

50

75

100

0 200 400 600 800 1000

Load Impedance (ohms)

Max

imu

m P

ow

er (

%)

Guide to Product Data Pages


Figure 3b Power curve: rated load of 500 ΩΩ

with a power curve having a broader peak, as inFigure 3b, tissue heating can continue until thetotal impedance of tissue grasped between thetines is well over 600Ω, as the power outputremains high above this value. Providing anappropriate selection of forceps size and powersetting is made, the second ESU is more likely tocoagulate the inner core of the fallopian tube.

In this review there is insufficient space forreproducing power curves for each device andmode. A key feature summarising the powercurve is the Maximum Power at the Rated Load.The Maximum Power and Rated Load are bothtabulated for each mode on the product data pages.

GUIDE TO PRODUCT DATA PAGES

There are a number of issues to consider whenconsidering which particular electrosurgical unitto purchase including clinical, technical, financialand legal. Each product summary page isdesigned to provide an overview of these issuesfor each device to assist in procurement decisions.You are advised to obtain information on the costof reusable / ‘single use’ accessories compatiblewith the ESU you are planning to purchase asthese can add significantly to the lifetime cost ofthe device. Limited space prevents inclusion ofaccessory data in these product summaries.

Price: All prices in this report exclude VAT. Forsome units a carriage charge may also be added.User manuals, accessories and active leads may beincluded in the price of the electrosurgical unit.Suppliers should be contacted for the currentprices of accessories. Some units can only be usedwith the manufacturer’s own accessories and it isimportant to determine that these are suitable foryour application.

Dimensions & Weight: Dimensions are listedconsistently for all units (width × height × depth, inmm). The weight (given in kg) coupled with thesize could significantly affect the procurementdecision if the ESU must be stored in a cupboardor transported between surgical sessions.

Full evaluation Report: Where available, the fullevaluation report should be consulted beforemaking a decision to purchase. These reportscontain user assessments, technical evaluations,and safety issues. Locally, they may be archivedin the Clinical Engineering or EBME Department.Alternatively, these are free to NHS staff (see backpage for contact details).

CE Marking: Manufacturers of medical devicesplaced on the market in Europe are required tomeet the relevant European Union MedicalDevices Directive. A classification of medicaldevices has been established denoting the risk ofthe device type for the patient, Class III having thehighest risk. The electrosurgical units listed in thisreview have been classified by the manufacturersas IIb. The routes to CE marking chosen by thesemanufacturers were through full quality assurance(ie the manufacturer’s design and manufacturingprocesses) audited and certified by a NotifiedBody.

Notified Body: This is an organisation authorisedby their national Competent Authority. In the UKthis is the Medical Devices Agency. The samesystem operates in all EC countries and a numberof Notified Bodies have branches in the USA,Japan, etc.

Manufactured to Standard: Certificate copiesreceived from the manufacturer or an independenttest house stating conformance with internationalstandards are summarised in this section.

EN 60601 is the European standard for electricalmedical devices, which is harmonised to theinternational standard. Special requirements forESUs are detailed in EN 60601-2-2. Please noteCE marking does not automatically mean that allESUs conform to the current, relevant internationalsafety standards.

Where the only certification received is related tothe manufacturer’s quality assurance system (egEN ISO13485 or EN 46001) this information isdetailed in this section. For these devicescompliance is only with the EssentialRequirements, the legal minimum.

0

25

50

75

100

0 200 400 600 800 1000

Load impedance (ohms)

Max

imu

m P

ow

er (

%)



Main Features: This section summarises the ESUmodes, special features, such as automaticcoagulation, and power control labelling. Thesefeatures are briefly described on pages 5 to 8.

Specifications: All devices should be matched tothe intended surgical application(s) in terms ofoutput power, rated load and peak voltage. Valueslisted are from the user manual. CEDARmeasured values were within permitted tolerances.

Maximum Power: The current flow delivered intoa specific load impedance, called the ‘rated load’,at the maximum power output setting is used tocalculate the maximum power output.

Rated Load: For each mode the rated load isusually the total impedance between the active andreturn electrode for which the ESU generatordelivers the highest power output.

Peak Voltage: The maximum open-circuit peakvoltage is listed for each mode. This is the highestvoltage away from zero, either in a positive ornegative direction measured between the activeand return electrodes when no tissue / load isconnected between them. Peak voltage is usefulfor giving an idea how far an electric spark froman active electrode can jump through the air.

Different voltages reflect the intended applicationsof each device. Cutting voltages must be above afew hundred volts, to develop the arc required forcutting, but low enough to avoid unwantedcharring or direct arcing between activeelectrodes. Contact coagulation peak voltages ofthe devices in this review range from 190 V to 3.5kV. Spray coagulation peak voltages may varyfrom 1.6 kV to 9 kV.

Matching the Device to the Surgical Task:Some ESUs are specialised, intended for oneparticular surgical field, whilst others provide arange of outputs and modes for a more generalrange of applications. The cost of a device shouldbe weighed against the range of applications (seeTable 2) and the frequency of use.

Maintenance: During it’s lifetime an ESU willneed routine preventative maintenance andpossibly repair. Any purchasing decision shouldinclude careful consideration of the servicing andmaintenance required and the cost and availabilityof technical training. Most suppliers offer serviceor maintenance contracts, though they may differin the level of cover they offer. Service manualsshould be available, though there may be a charge.

PROCUREMENT ISSUES

Controls Assurance Standard: Trust boards musttake responsibility for ensuring there are safesystems in place to minimise the risks associatedwith the acquisition and use of medical devices(www.casu.org.uk àstandards àmedical devices).

Current Production: Manufacturers may continueto modify products after this report is published.Please note that the version you buy may differfrom the one evaluated.

Compliance with Safety Standards: If a devicecomplies with the relevant harmonisedinternational standard (see page 9) this will beaccepted as evidence that the device meets theEssential Requirements of the Medical DevicesDirective. Devices included in this report may becertified to, or the manufacturer claims compliancewith, these standards. Further advice about theseissues can be obtained from the manufacturer,hospital Clinical Engineering, EBME or MedicalPhysics Departments or the British StandardsInstitute (www.bsi-global.com).

Purchasing Assessment: It is intended that thisreview and other full evaluations should assistpurchasers in carrying out a rigorous specificationand assessment process. Suppliers should becontacted for the latest product information andprices. Product demonstrations and trials may alsobe arranged prior to purchasing. Thought shouldbe given to the lifetime cost of a unit, includingaccessories and maintenance.

Indemnity Insurance: Loan-unit indemnityarrangements between the suppliers and NHSSupplies in England, Wales, Scotland and NorthernIreland have not been verified for devices in thisreview.

Training: User knowledge and skills have majorimplications for safety. Instructions, both the usermanual and local protocols, must be clear, conciseand readily available. Training of staff in the use ofequipment needs to be timely and effective. Usersand technicians need to understand the basicprinciples on which the ESU works (generictraining) as well as how to use a particular model(specific training). Training programmes should,where possible, include input from manufacturersand independent experts. Procurement of a newmedical device should include a resourceallocation for user training. Strategic procurementpolicies will reduce training time if the number ofdifferent models is limited.



SurgicalApplications

Aar

on

Bo

vie

1250

Aar

on

Bo

vie

2100

Co

nM

ed H

yfre

cato

r 20

00

Ellm

an S

urg

itro

n D

ual

Fre

qu

ency

Ellm

an S

urg

itro

n R

adio

lase

Erb

e IC

C 5

0

Erb

e IC

C 8

0

Erb

e IC

C 2

00

Ko

rpo

Tim

ed T

D 5

0 A

Mar

tin

MD

62

Mar

tin

ME

102

Mar

tin

ME

200

Oly

mp

us

PS

D-3

0

Uta

h M

edic

al F

ines

se

Val

leyl

ab S

urg

ista

t II

Cardiac

Chiropody

Colposcopy

Dental & Oral

Dermatology

ENT

Endoscopy

Gasteroenterology

General Surgery

Genitourinary

Gynaecology

Laproscopic

Maxillofacial

Microsurgery

Minor surgery

Ophthalmology

Orthopaedics

Neurosurgery

Paediatric

Plastic and Reconstructive

Thoracic

Urology (general)

Vascular

Vasectomy

Table 2 Manufacturers’ Principal Intended Applications

Aaron Bovie 1250


BRIEF DESCRIPTION

The Aaron 1250 is a compact, rf-isolated, solid-state electrosurgical unit. The device is ratedType BF and has a duty cycle of 10 seconds onfull power followed by 30 seconds off.

The Aaron 1250 is intended for all low to mediumpower range specialities, this includes; generalsurgery, both open and laparoscopic,gynaecology, dermatology, ENT, maxillofacial,orthopaedics, plastic surgery, neurosurgery,paediatric, cardiac and thoracic surgery andendoscopy. The 1250 is not suitable for urology.

Dimensions 260 × 152 × 305 mm (W) (H) (D)

Weight 6.5 kg

MAIN FEATURES

Facilities

• Cut Cut, Blend

• Coagulation Coagulation, Fulguration, Bipolar

• Power control Rotary, display in Watts

Specifications

Safety Features

• Return electrode continuity monitor

• Patient contact monitor

• Connection for simultaneous activation ofsmoke filtration

Operating Switches

• Footswitches twin electrical

• Handswitches fingerswitching pencil (monopolar)

SERVICINGA loan service is provided when units are returnedfor servicing OR hospital visits may be arranged.

Typical Servicing Costs

• Annual comprehensive repair/preventativemaintenance contract (inc. parts) ** £ 375** Reductions available depending on location

• Service Training Price on Application

• Service Manual £ 70

Full Report Brief Assessment

CE Marking? Yes, MD DirectiveQuality System Audit

Notified Body ITS SEMKO-AB (0413)

Manufacturedto Standard?

Manufacturer claimscompliance withEN 60601:1990 with A1, A2,A12 &A13and EN 60601-2-2 :1998

SUMMARY

• 120 W monopolar, 30 W bipolar

• Cut, blend and coagulation modes

Supplier Avail Medical Europe LtdThe Coach HouseDosthill HallDosthillTamworthStaffordshire, B77 [email protected]

Tel: 01827 288 883Fax: 01827 288 334Web: www.aaronmed.com

Price £3,500

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 120 W 500 Ω 1.4 kV

Blend 90 W 800 Ω 2.0 kV

Coag 80 W 1000 Ω 3.3 kV

Fulgurate 40 W 1000 Ω 4.0 kV

Bipolar 30 W 200 Ω 1.25 kV

Aaron Bovie 2100


BRIEF DESCRIPTION

The Aaron 2100 is a compact, rf-isolated, solid-state electrosurgical unit. The device is ratedType CF and has a duty cycle of 10 seconds onfull power followed by 30 seconds off.

The Aaron 2100 is a multipurpose electrosurgicalgenerator for use in surgical operating theatresand centres for day case surgery. This includes;general surgery (including laparoscopic surgery),cardiovascular, gynaecology, dermatology, ENT,neurosurgery, orthopaedics, plastic surgery,endoscopy, paediatrics and maxillofacial surgery.The 2100 is not recommended for urology.

The 2100 provides nine blend settings, for differinghaemostatic effect, in addition to pure cut,coagulation, fulguration and bipolar modes.

Dimensions 380 × 152 × 460 mm

Weight 7.2 kg

MAIN FEATURES

Facilities

• Cut Cut, Blend (10% -100%)

• Coagulation Forced Coagulation, Fulguration, Bipolar

• Power control Digital, display in Watts

• Active output control Optisense

• Memory of last setting for each mode

• PC interface for ease of servicing

Specifications

Safety Features

• Return electrode continuity & patient contactmonitor


Operating Switches

• Footswitches twin electrical

• Handswitches fingerswitching pencil (monopolar)

SERVICINGA loan service is provided when units are returnedfor servicing OR hospital visits may be arranged.


• Annual comprehensive repair/preventativemaintenance contract (inc. parts) ** £ 375** Reductions available depending on location

• Service Training Price on Application

• Service Manual FREE



Notified Body ITS SEMKO-AB (0413)


Manufactured underEN46001:1996

SUMMARY


• Cut and variable blend (9 settings)

• Contact and spray coagulation modes

• Impedance sensing

Supplier Avail Medical Europe LtdThe Coach HouseDosthill HallDosthillTamworthStaffordshire, B77 [email protected]

Tel: 01827 288 883Fax: 01827 288 334Web: www.aaronmed.com

Price £4,450

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 200 W 500 Ω 800 V

Blend 100% 200 W 500 Ω 1250 V

Coag 140 W 800 Ω 1350 V

Fulgurate 80 W 1000 Ω 3500 V

Bipolar 80 W 150 Ω 450 V

ConMed Hyfrecator 2000


BRIEF DESCRIPTION

The ConMed Hyfrecator 2000 is a low power,earth-referenced electrosurgical unit. The deviceis rated type BF and has a duty cycle of 30seconds on full power, followed by 30 seconds off.

Spray coagulation and contact coagulation may beachieved using the HI or LO output modes,respectively. Bipolar coagulation requires the useof a footswitch and provides precise coagulation orhaemostasis.

No patient return electrode is required inmonopolar modes as the low powers involvedmean that sufficient current can be returned to theHyfrecator unit by environmental capacitivecoupling. More effective coagulation can beachieved when using the optional return electrodewith either the HI or LO outputs. The returnelectrode provides a more efficient path for theelectrosurgical current and increased coagulationresults. Power settings may need to be reduced tocompensate for the increased surgical effect.


Weight 2⋅7 kg

MAIN FEATURES

Outputs

• Monopolar Coagulation LO (contact coag)HI (spray coag)

• Bipolar Coagulation BI


Specifications

Operating Switches

• Footswitches

mono/bipolar single electrical

• Handswitchesmonopolar fingerswitching

pencil withpower control

bipolar none

SERVICING

The ConMed Hyfrecator 2000 can be serviced in-house or returned to the UK agent. It is intendedthat the unit be returned to the supplier for repair.A comprehensive service manual is availableincluding full circuit diagrams.


• Full service £ 52(exc. materials & carriage)

• Inspection and testing (exc. carriage) £ 29




Notified Body TÜV Münich (0123)


Manufacturer claimscompliance with EN60601-1,EN60601-1-2, EN60601-1-4and EN 60601-2-2

SUMMARY


• Intended for minor surgical treatments

• Three Coagulation modes

Supplier Schuco International London LtdLyndhurst AvenueLondon N12 ONE

Tel: 0208 368 1642Fax : 0208 361 3761Web: www.schuco.co.uk

Price Basic ESU £ 715 plus footswitch £ 830 plus bipolar & footswitch £ 962

Facility MaximumPower

RatedLoad

PeakVoltage

LO 20 W 500 Ω 2000 V

HI 35 W 1000 Ω 6000 V

BI 35 W 500 Ω 1500 V

Ellman Surgitron Dual Frequency


BRIEF DESCRIPTION

The Ellman Surgitron Dual Frequency is acompact, solid state, earth-referencedelectrosurgical unit. The device is rated Type BFand has a duty cycle of 10 seconds on full powerfollowed by 30 seconds off.

The Surgitron IEC is primarily intended foroutpatient procedures in dermatology, plasticsurgery, ENT, maxillofacial and ophthalmology.This is similar to the Surgitron IEC (evaluationreport 402). Principal upgrades: high frequency(4MHz) now used for all monopolar modes; athree-button fingerswitch hand-piece, for activatingpower on and selecting the activation mode.

The patient contact monitor permits a maximumimpedance of 1000 Ω; this is higher than similarmonitoring systems and less effective for detectingpartial detachment of the return electrode.


Weight 8.16 kg

MAIN FEATURES

• Cut CutCut/Coag (blend)

• Coagulation Hemo (contact coag)Fulgurate (spray coag)Bipolar


Specifications

Safety Features


• Contact quality monitor (see Brief Description)

Operating Switches

• Footswitches dual electrical(mono & bipolar)

• Handswitches fingerswitchingpencil (3 buttons)

SERVICINGAs required and contract servicing arrangementsare available.

Typical Servicing CostsThe Ellman Surgitron Dual Frequency can beserviced by the user or a service contract with thesupplier, which includes the cost of carriage andany parts used in the annual service andcalibration check. If repairs to the ESU arerequired this charge covers labour costs only.

Typical Servicing costs

• Service Contract (per year) £150

• Service Manual 2 copies supplied FREE

Full Report Manufacturers data only


Notified Body ITS-SEMKO AB(0413)


Manufacturer claimscompliance withEN60601-1-1:1992, EN60601-1-2:1993, EN60601-1-4:1997 and EN60601-2-2:1991.

SUMMARY


• Cut and coagulation modes

• 4 MHz rf output in monopolar modes

• 1.71 MHz rf output in bipolar mode

Supplier Ellman International (UK) Ltd16 Ryehill CourtLodge FarmNorthampton, NN5 7EU

Tel: 01604 589928Fax: 01604 759098Web: www.ellman.com

Price £8,750

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 100 W 500 Ω

Cut/Coag 75 W 500 Ω

Hemo 35 W 500 Ω

Fulgurate 32 W 500 Ω

Bipolar 38 W 500 Ω

Dat

a no

t ava

ilabl

e

Ellman Surgitron Radiolase


BRIEF DESCRIPTION

The Ellman Radiolase is a compact, low power,solid-state, earth referenced electrosurgical unit.The device is rated Type BF and has a duty cycleof 10 seconds on full power followed by 30seconds off.

The Radiolase is intended for use in minor surgicaloutpatient based procedures such as dermatology,plastic surgery, ophthalmology, and dentalsurgery.

The manufacturer claims that using a higherfrequency (4 MHz) can be beneficial in terms oflessening tissue damage, reduced acarring andmore rapid healing.

Due to the higher than usual radio frequency(4.0MHz) used by the Radiolase, a small areacapacitive return electrode is available as anoption to the more usual conductive, adhesivereturn plates.


Weight 3.35 kg

MAIN FEATURES

Outputs

• Cut CutCut/Coag (blend)

• Coagulation Hemo (contact coag)

• Power control rotary, continuouslabelled 0 - 10

Specifications

Operating Switches

• Footswitch single electrical

• Handswitch single fingerswitch

SERVICINGThe Ellman Surgitron Radiolase can be servicedby the user or a service contract with the supplier,which includes the cost of carriage and any partsused in the annual service and calibration check. Ifrepairs to the ESU are required this charge coverslabour costs only.

Typical Servicing costs

• Service Contract (per year) £150

• Service Manual 2 copies supplied FREE


CE Marking? Yes, MD DirectiveQuality system audit

Notified Body ITS-SEMKO AB (0413)


Manufacturer claimscompliance withEN60601-1-1:1992, EN60601-1-2:1993, EN60601-1-4:1997 and EN60601-2-2:1991.

SUMMARY

• 50 W monopolar


• Earth referenced

• 4 MHz operating frequency

Supplier Ellman International (UK) Ltd16 Ryehill CourtLodge FarmNorthampton, NN5 7EU

Tel: 01604 589928Fax: 01604 759098Web: www.ellman.com

Price £ 2,095

FacilityMaximum

PowerRatedLoad

Peak#

Voltage

Cut 50 W 500 Ω 300 V

Cut/Coag 34 W 500 Ω 300 V

Hemo 16 W 500 Ω 300 V# CEDAR measurements, not stated in the user manual

ERBE ICC 50


BRIEF DESCRIPTION

Erbe ICC50 is a compact, low powered micro-processor controlled electrosurgical unit. The unitis rf isolated, rated Type CF and is capable ofcontinuous operation. Nominal frequency is350kHz in all modes.

Erbe ICC50 is appropriate for minor surgicalprocedures and use in outpatient clinics, such asdermatology and oral surgery.

Two pre-programmed default settings formonopolar cutting are provided called Auto CutEffect modes. Auto Cut Effect 1 provides a puresinusoidal cut (Crest factor = 2). Auto Cut Effect 2is a blended waveform providing coagulation at thecut surface (Crest factor = 4 ).

Soft and Forced monopolar coagulation can beactivated by footswitch or pedal. Bipolarcoagulation is only activated by footswitch.


Weight 2.8 kg

MAIN FEATURES

• Automatic voltage control – CUT CONTROL

• Coagulation forcedsoft (voltage limited at high Ω)

bipolar (voltage ltd at high Ω)


Specifications

Safety Features

• Switch on safety check includes accessories


• Activation Time Limit (adjustable 1 - 99 secs)

• Start-up self-check & Output Error Monitor

Operation Switches

• Footswitches monopolar twin electricalbipolar coag mono pedal

• Handswitches monopolar fingerswitchingbipolar none

SERVICINGThe ERBE ICC50 can be serviced by the user, aservice contract with the supplier or returning theunit to the supplier. The supplier provides variouslevels of service contract, some are listed below:


• Contracted repair & preventativemaintenance (per year) £ 450.45

• as above but excluding parts £ 343.35

• Non-contract emergency call-out ratelabour/travelling/waiting per hour £ 68.25

• Return to supplier, labour per hour £ 50.93

• Service Manual £ 35.00


CE Marking? Yes, MD Directive

Quality System Audit

Notified Body DEKRA (0124)


Manufactured underEN 46001

SUMMARY

• 50 W monopolar, 50W bipolar

• Auto Cut – providing initial power surge

• Soft Coag – voltage limited

• Pre-set voltage response to tissue load

Supplier ERBE Medical UK LtdThe Antler Complex2 Bruntcliffe Way, MorleyLeeds, LS27 0JGTel: 0113 253 0333Fax: 0113 253 2733Web: www.erbe-med.com

Price £ 1,700

ModeMaximum

PowerRatedLoad

PeakVoltage

Auto Cut (1) 50 W 500 Ω 500 V

Auto Cut (2) 50 W 500 Ω 800 V

Soft Coag 50 W 200 Ω 190 V

Forced Coag 50 W 500 Ω 900 V

Bipolar Coag 50 W 200 Ω 190 V

Erbe ICC80


BRIEF DESCRIPTION

Erbe ICC80 is a micro-processor controlledelectrosurgical unit designed for minor surgeryprocedures. Appropriate for use in outpatientclinics and specialised medical practices such asoral surgery and dermatology.

The unit is rf isolated, rated Type CF and iscapable of continuous operation. Nominalfrequency is 330kHz in all modes.

Two Auto Cut Effect modes are provided: Auto CutEffect 1 is a pure sinusoidal cut (Crest factor = 2),Auto Cut Effect 2 is a blended waveform providingcoagulation at the cut surface (Crest factor = 4 ).Both Auto Cut modes incorporate the CUTCONTROL to facilitate a smoother cutting action.

Soft and Forced monopolar coagulation andBipolar coagulation are available on this unit.

Fingerswitch activation is available for monopolarmodes. The foot switch will activate all modes.


Weight 2.8 kg

MAIN FEATURES





Specifications

Safety Features

• Switch on safety check includes accessories

• Return electrode continuity and contact qualitymonitor (dual plate electrodes only)


• Start-up self-check & Output Error Monitor

SERVICING

The ERBE ICC80 can be serviced by the user, aservice contract with the supplier or returning theunit to the supplier. The supplier provides variouslevels of service contract, some are detailedbelow:












ModeMaximum

PowerRatedLoad

PeakVoltage

Auto Cut (1) 80 W 500 Ω 500 V

Auto Cut (2) 80 W 500 Ω 500 V




SUMMARY

• 80 W monopolar, 50W bipolar

• Auto Cut – providing initial power surge

• Soft Coag – voltage limited

• Pre-set voltage response to tissue load


Price £ 1,800

ERBE ICC 200


BRIEF DESCRIPTION

Erbe ICC200 is a micro-processor controlledelectrosurgical unit for general application andincludes specific features designed for minimallyinvasive surgery. The unit is rf isolated, rated TypeCF and is capable of continuous operation. Thenominal frequency is 350kHz in most modes.Spray and forced coagulation operate at 1MHz.

Four Auto Cut Effect modes are standard, allincorporating the Power Peak System to facilitatea smoother cutting action. Auto Cut Effect 1 is apure sinusoidal cut, with Auto Cut Effects 2 to 4being blended waveforms increasing thecoagulation of the cut surface. Endo Cut (option) isa fractionated cut for delicate cutting.

Soft & Forced monopolar coagulation and bipolarcoagulation are standard. Auto Start for bipolarcoagulation (either immediate or delayed) isdisabled for the UK market. Spray & Argon plasmacoagulation is available as an optional extra.

Dimensions 280 × 152 ×368 mm

Weight 8.0 kg

MAIN FEATURES

• Power Peak System – burst of power (highervoltage) to initiate cutting action





Specifications

Safety Features• Return electrode continuity and contact quality

control monitor also checks on returnelectrode orientation (NESSY)


• Output Error Monitor

SERVICING

The ERBE ICC200 can be serviced by the user, aservice contract with the supplier or by returningthe unit to the supplier.








CE Marking? Yes, MD Directive



Certified by DEKRA ascomplying with:EN 60601-2-2: 1991

SUMMARY• 200 W monopolar, 120 W bipolar• Auto Cut – providing initial power surge• Soft Coag – voltage limited• Programmable settings memory (single)


Price £ 3,200

Options endoscopic cut £ 800 spray and argon beam

coagulation £1,400

ModeMaximum

PowerRatedLoad

PeakVoltage

Auto Cut 200 W 500 Ω 650 V

Endo Cut 200 W 500 Ω 650 V



Spray Coag 120 W 500 Ω 4000 V


Korpo Timed TD 50 A

MDA evaluation 02037 March 2002 20

BRIEF DESCRIPTION

The Korpo TD 50 A Micropulse is a rf-isolated, lowpower, solid-state electrosurgical unit. The deviceis rated Type CF and is capable of continuousoperation.

Two modes are available, ‘cut’ and ‘coag microelect’, the monopolar outputs are each rated at49.5 W. Both these outputs are available in abipolar configuration with slightly reduced powersand peak voltages. The bipolar power outputs andconfigurations are poorly explained in the manual.The manufacturer will resolve this in future copies.

A compact disk is also supplied detailing manydermatological and other minor procedures,recommended electrodes, outputs and timedfunctions.

The TD 50 A has a specialist timed function,where the output is activated for a programmablefraction of a second each time the footswitch isdepressed. Five pre-programmed pulsedfunctions enable continuous pulsed operation witha range of frequencies and active periods.

The device is designed to be used with specialisedactive electrodes supplied by the manufacturer.The return electrode supplied with the ESU is rigidso care must be taken to ensure adequate patientcontact. Disposable electrodes can also be used.


Weight 8 kg

MAIN FEATURES

Facilities

• Monopolar CutCoag Micro Elect

• Bipolar CutCoag Micro Elect

• Power control rotary, 12 settings labelled in Watts

Specifications

# CEDAR measurements, not stated in the user manual.

Safety Features

• High frequency leakage monitor


Operating Switches

• Footswitches single pneumatic

• Handswitches none

SERVICING

It is intended that the Timed TD 50 A be returnedto the supplier in the event of a fault. Routinesafety and function testing can be carried out in-house or by returning the unit to the supplier.


• Return to supplier preventative maintenancecharge, excluding parts and carriage(1 recommended per year) £150

• Return to supplier, labour per hour £35



Notified Body IMQ (0051)

Manufactured toStandard?

Manufacturer claimscompliance withEN 60601-2-2: 1993

SUMMARY


• Cut and coagulation modes

• Variable timed-activation function

Supplier Fram DiathermyGlebe HousePencombeHerefordshireHR7 4RL

Tel & Fax: 01885 400258

Price £2,310


RatedLoad

PeakVoltage

MonopolarCut

49⋅5 W 800 Ω 420 V

MonopolarCoag

49.5 W 800 Ω 580 V

BipolarCut #

40 W 800 Ω 330 V

BipolarCoag #

40 W 800 Ω 470 V

Martin MD 62


BRIEF DESCRIPTION

The Martin MD 62 is a low power, earth referencedelectrosurgical unit. The device is rated Type BFand has a duty cycle of 10 seconds on full power,followed by 30 seconds off.

The primary intended application is in dentalsurgery where the device may be used without areturn electrode in the monoterminal mode. In thismode, the patient must be seated in an eartheddental chair or hold a hand cylinder (returnelectrode) to ensure safe operation. Since thedevice is earth referenced it is especially importantthat the patient does not touch any earthed metalobjects.

The device is supplied with either, a rubber coatedcapacitive return electrode or a metal cylinderconductive return electrode to be gripped by thepatient’s hand. The usual considerations on thesafe placement of return electrode apply in thismode of operation.


Weight 2.8 kg

MAIN FEATURES

• Monopolar CutCoag

• Power control rotary, continuouslabelled 0 - 10

Specifications

Operating Switches

• Footswitches single pneumatic

• Handswitches fingerswitching pencil

SERVICING

It is intended that the Martin MD 62 be returned tothe supplier in the event of a fault. Routinepreventative maintenance can be carried out in-house or by returning the unit to the supplier.


• Return to supplier labour per hour £ 35




Notified Body DQS (0297)



SUMMARY

• 50 W monopolar

• Cut and coagulation

• Intended for dentistry, dermatology andminor cosmetic surgery

Supplier Albert Waeschle Ltd123/125 Old Christchurch RoadBournemouthDorset, BH1 1EX

Tel: 01202 204803Fax: 01202 204800Web: www.martinmedizintechnik.de

Price £ 750

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 50 W 600 Ω 600 V

Coag 30 W 1200 Ω 1300 V

Martin ME 102


BRIEF DESCRIPTION

The Martin ME 102 is a rf-isolated, solid-state,electrosurgical unit. The device is rated Type CFand has a duty cycle of 10 seconds on full powerfollowed by 30 seconds off.

All outputs have a micro option that reduces thepower to a third of normal values, allowingenhanced precision in the selection of lowerpowers.

The device may also used with a large areacapacitive return electrode. This electrode shouldonly be used in procedures that allow for safesiting of the plate with regard to currentconcentrations and tissue pressure.

The ME 102 has a dual mode operational facility,allowing the user to switch between monopolarand bipolar without the need to select a switch onthe control panel. Only one output can beenergised at any one time, on a first come firstserved basis.


Weight 4.6 kg

MAIN FEATURES• Monopolar Cut 1

Cut 2 (blend)Contact coagulation

• Bipolar Coagulation

• Power output Rotary, continuouslabelled 0 – 10

• MICRO power ~ third of normal o/p

Specifications (Macro modes)

Safety Features


• Contact quality monitor (if split plate is used)

Operating Switches

• Footswitches Monopolar (twin electrical)Bipolar (single electrical)

• Handswitches Fingerswitching pencil

• Automatic start Bipolar mode only

SERVICINGIt is intended that the Martin ME 102 be returnedto the supplier in the event of a fault. Routinepreventative maintenance can be carried out in-house or by returning the unit to the supplier.


• Return to supplier, labour per hour £ 35







SUMMARY



• Automatic bipolar switching

• MICRO control for low power outputs

Supplier Albert Waeschle Ltd.123/125 Old Christchurch RoadBournemouthDorset, BH1 1EX


Price £ 1,795

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 1 100 W 600 Ω 600 V

Cut 2 (blend) 90 W 600 Ω 800 V

Contact coag 70 W 600 Ω 1000 V

Bipolar 80 W 100 Ω 220 V

Martin ME 200


BRIEF DESCRIPTION

The Martin ME 200 is a rf-isolated, solid state,electrosurgical unit. The device is rated Type CFand has a duty cycle of 10 seconds on full powerfollowed by 30 seconds off.

Cut 1 mode has a pure sinusoidal cuttingwaveform. Other Cut modes are blend waveformswith an increasing depth of coagulation. All outputshave a micro option, reducing the power to a thirdof normal values, allowing enhanced precision inthe selection of lower powers.

The ME 200 may also be used with a large areacapacitive return electrode supplied by Martin.This return electrode should only be used inprocedures that ensure safe siting, minimisingcurrent concentrations and tissue pressure.

The device allows simultaneous activation ofbipolar and one monopolar output. The footswitchactivated monopolar output takes priority over thehandswitched output.


Weight 9.6 kg

MAIN FEATURES

• Monopolar Cut1 (pure) & 2-4 (blend)Coag: spray & contact

• Bipolar Coagulation

• Power control Rotary , continuouslabelled 0 – 10

• MICRO power ~ third of normal o/ppeak voltage is halved

Specifications

Safety Features


• Contact quality monitor (if split plate is used)

• Activation time limit alarm

Operating Switches

• Footswitches Monopolar (twin electrical)Bipolar (single electrical)

• Handswitches Fingerswitching pencil

• Automatic start Bipolar mode only

SERVICINGIt is intended that the Martin ME 200 be returnedto the supplier in the event of a fault. Routinepreventative maintenance can be carried out in-house or by returning the unit to the supplier.


• Return to supplier, labour per hour £ 35







SUMMARY


• Cut, blend, dessication & spray coagulation

• Automatic bipolar switching

• MICRO control for low power outputs

• Intended for general surgery applications

Supplier Albert Waeschle Ltd.123/125 Old Christchurch RoadBournemouthDorset, BH1 1EX


Price £ 3,440

FacilityMaximum

PowerRatedLoad

PeakVoltage

Cut 1 175 W 500 Ω 700 V

Cut 2 175 W 500 Ω 1100 V

Cut 3 175 W 500 Ω 1300 V

Cut 4 175 W 500 Ω 1500 V

Spray coag 100 W 500 Ω 1600 V

Contact coag 175 W 300 Ω 1100 V

Bipolar coag 70 W 100 Ω 200 V

Olympus PSD-30


BRIEF DESCRIPTION

The Olympus PSD-30 is a solid state, rf-isolatedmonopolar electrosurgical unit rated Type CFreplacing the PSD-20 (evaluation Report 343). Ithas a duty cycle of 10 seconds on full powerfollowed by 30 seconds off.

The PSD-30 is a specialist unit, designed for useexclusively with the Olympus flexible endoscopesystem. This incorporates the S-cord system sohigh frequency surgical current leaked to theendoscope is returned directly to the ESUgenerator. Operation can only be activated by atwin electrical footswitch.

The device is intended for low-power gastro-intestinal and broncho-endoscopic proceduressuch as polypectomies & sphincterotomies.

Dimensions 295 × 160 × 420 mmWeight 7.9 kg

MAIN FEATURES• Monopolar Cut : Pure, Blend 1 & 2,

Coag : Forced, Soft & AutoStop

• Monitoring tissue impedance (Auto Stop only)

• Footswitch two pedal electrical

• Programme Memory


Specifications

Safety Features• S-cord returns leakage current in endoscope• Contact quality monitor if split-plate used• Return electrode & S-cord continuity monitor• Return current feedback ratio monitor• Activation time limit• Output error monitor

SERVICINGThe Olympus PSD-30 can be serviced in-housebut annual return of units to the supplier forpreventative maintenance is recommended. Twolevels of service contract are available, standardand comprehensive.

Typical Servicing Costs• Standard repair/preventative maintenance

contract (excluding parts) per year £ 330

• Annual comprehensive repair/preventativemaintenance contract (inc. parts) £ 665

• Return to manufacturerlabour per hour £ 60




Notified Body TÜV Rheinland (0197)


Manufacturer claimscompliance with EN 60601-2-2

SUMMARY

• 50 W monopolar


• Endoscope safety connection andmonitoring

• Intended for use with the Olympus flexibleendoscope system

Supplier KeyMed LtdKeyMed HouseStock RoadSouthend-on-SeaEssex, SS2 5QH

Tel: 01702 616333Fax: 01702 465677

www.keymed.co.uk

Price £6,610

FacilityMaximum

PowerRatedLoad

Peak#

Voltage

Pure cut 50 W 300 Ω 480 V

Blend 1 50 W 300 Ω 380 V

Blend 2 50 W 300 Ω 420 V



AutoStop 50 W 100 Ω 240 V# CEDAR measurements, not stated in the user manual

Utah Medical Finesse


BRIEF DESCRIPTION

The Utah Medical Finesse is a rf-isolated, solid-state electrosurgical unit. The device is ratedType CF and has a duty cycle of 10 seconds onfull power followed by 30 seconds off.

The Finesse is designed to automatically adjustthe voltage of cut and blend outputs to maintain aconstant effect through different tissue depths.The coagulation mode provides sufficient voltageand power for spray coagulation.

The Finesse system has been developed to beparticularly suitable for loop excisions of thecervical transformation zone and othergynaecological procedures. It also hasapplications in other outpatient proceduresincluding dermatology and plastic surgery.

The primary HEPA filter should be changed on adaily basis; the internal ULPA filter should berenewed annually. The device has a carryinghandle at the rear.


Weight 10 kg

MAIN FEATURES

Facilities

• Monopolar cut,blend 1, 2, 3coagulation

• Impedance sensing for controlling power o/p

• Power control Rotary, displaylabelled 0 - 99

Specifications

Safety Features

• Output power error monitor• Integral smoke extraction and filtration system

turned on during ESU activation if selected

Operating Switches

• Footswitches twin electrical• Handswitches fingerswitching

pencil

SERVICINGThe Finesse can be serviced by the qualifiedtechnical personnel in the user’s hospital or byreturning the unit to the manufacturer’s servicingfacility in Ireland. Annual service contracts arealso available.

Typical Servicing Costs• Annual service contract: repair & preventative

maintenance (inc. parts and carriage) £ 350• Non-contract repair per hour £ 60• Return to supplier, labour per hour £ 60• Service Manual FREE



Notified Body NSAI (0050)


Certified by G-MED ascomplying withEN 60601-2-2: 1993


RatedLoad

Peak #

Voltage

Cut 150 W 200 Ω 490 V

Blend 1 150 W 200 Ω 1000 V

Blend 2 150 W 200 Ω 1000 V

Blend 3 150 W 200 Ω 1000 V

Coag 75 W 500 Ω 1800 V# CEDAR measurements, not stated in the user manual

SUMMARY

• sold as 100 W monopolar (max. at 500 Ω)but maximum output is 150 Watts at 200 Ω.


• Integral smoke evacuation and filter unit

• Active power/voltage management

Supplier Euro Surgical LtdMerrow Business CentreGuildfordGU 4 7WA

Tel: 01483 456007Fax: 01438 456008Web: www.eurosurgical.co.uk

Price £ 5,620

Valleylab Surgistat II


BRIEF DESCRIPTION

The Valleylab SurgistatTM II is a compact, rf-isolated, solid-state electrosurgical unit. Thedevice is rated Type CF and has a duty cycle of 10seconds on full power followed by 30 seconds off.

The Surgistat II is intended for lower-poweredelectrosurgical applications, eg in outpatientclinics. The device is recommended forprocedures such as colposcopy, endoscopy, anddermatology.

Handswitching bipolar forceps are available onrequest.

On power up a self-test is automatically performedand then the last power setting for each mode isloaded from memory.

Dimensions 260 × 140 ×254 mm

Weight 6.5 kg

MAIN FEATURES

• Cut Pure Cut & Blend

• Coagulation Desiccate, Fulgurate& Bipolar


Specifications

Safety Features


• Contact quality monitor (if split plate used)


Operating Switches

• Footswitches twin electrical(mono and bipolar)

• Handswitches fingerswitchingpencil (monopolar)

SERVICING

Routine safety and function testing can be carriedout in house. The Surgistat II can be serviced byreturn to the supplier / service centre. Loan serviceavailable.

Typical Servicing Costs• Contracted preventative maintenance for

1, 2 or 3 units, per year (2 visits) £620• Emergency call-out rates,

labour/travelling/waiting per hour £601

• Return to service dept (labour/hour) £601

• Service Manual £601 Add £25 for non-contract rates.



Notified Body BSI (0086)



SUMMARY



• Intended for general low powerapplications

Supplier Tyco Healthcare154 Fareham RoadGosportHampshire, PO13 OAS

Tel: 01329 224114Fax: 01329 224260

Web: www.valleylab.com

Price £3,500

FacilityMaximum

PowerRatedLoad

Peak#

Voltage

Pure Cut 120 W 500 Ω 1400 V

Blend 90 W 800 Ω 2000 V

Desiccate 80 W 1000 Ω 3300 V

Fulgurate 40 W 1000 Ω 4000 V

Bipolar 30 W 200 Ω 1250 V# CEDAR measurements, not stated in the user manual

Appendix


GLOSSARY OF TERMS used in ELECTROSURGERY

AC (Alternating Current)Current direction and voltage polarity vary withtime. The rate of variation is called frequency.

Alternate Site BurnsUnwanted tissue damage due to concentratedcurrent at a location remote from the surgical site.Such burns may be caused by contact betweenthe patient and another conductive object,unintended activation, or carelessness with a hotelectrode after activation has stopped.

ArcSparking across an ionised air gap, resulting invery high concentrations of current where thespark makes contact with the target tissue.

Capacitive CouplingTransfer of electric current across an insulator orair gap by generating a changing electric field.This effect increases at high frequencies, highvoltages and small separation distances.

Conductive (Direct) CouplingTransfer of electric current through a conductingmedium, such as metal, saline or blood.

Crest FactorThe peak voltage divided by the average voltage(rms) is an indicator of the voltage waveform.Typical values are 1.5 for a cutting waveform andapproximately 8 for spray coagulation.

Current (I)The electric charge flowing through a region in onesecond; measured in amps (A). Batteries producedirect current (DC). Electrosurgical current is AC.

Current DensityThe amount of current passing through an area;measured in amps per square metre (Am-2). Thecurrent density or concentration determines theamount of heat generated in the tissue.

Current DivisionElectrical current leaving the intendedelectrosurgical circuit, between the active andreturn electrodes, and following an alternate pathof least resistance, through metal objects or fluids,to earth. A frequent cause of alternate site burns.

DiathermyHeating of body tissues caused by an impedanceto the flow of high frequency electric current. It hasnumerous surgical and physiotherapy applications.

DesiccationRemoval of water from cells resulting indehydration and considerable tissue shrinkage.

Earth ReferencedA connection to earth (ground) at high frequenciesby components such as a capacitor, so mainsfrequency current is not allowed to pass to earth.

Insulated / IsolatedNo conductive path between electrical conductorsor with earth. At high frequencies capacitive andinductive coupling may produce current flow.

EscharA charred crust resulting from high temperaturedestruction of the cell structure, eg by arcing.

FrequencyThe number of times a periodic cycle repeats inone second; measured in hertz (Hz). Frequenciesabove 100kHz are denoted rf as they are in thesame range used for radio-transmission.

Impedance (called Resistance if direct current)Opposition to the flow of a high frequency electriccurrent; measured in ohms (Ω).

Inductive CouplingTransfer of electric current across an insulator orair gap by a changing magnetic field. Coiled leadsand high frequencies increases this effect.

Leakage CurrentsCurrents that arise by capacitive and inductivecoupling between conductors that are electricallyinsulated from one another. The human body is alarge and efficient conductor and currents may beinduced at electrosurgical frequencies.

PowerRate at which energy is produced or consumed,measured in watts (W). Power is directly related toVoltage×Current or Impedance×Current×Current.

Return ElectrodeAlso known as neutral electrode, dispersiveelectrode, return plate, neutral plate or dispersiveplate. The large area of the return electroderesults in a low current density in the underlyingtissue and a small skin-temperature rise.

Surgical DiathermyAnother term for electrosurgery. Application ofhigh frequency electrical current to achieve avariety of surgical effects including cutting,coagulation and desiccation.

Voltage (V)The force that drives electrons (electric current)through a circuit, wires, tissue, air gap, etc. It ismeasured in volts (V).

WaveformThe pattern of electrical activity generated. Usuallya graphical display of changing voltage over time.

Appendix


ACKNOWLEDGEMENTS

This report was prepared by Dr Diane Crawford, Dr Nicholas Cook and Dr Stephanie Wentworth ofCEDAR (Clinical Engineering Device Assessment and Reporting), Medical Physics and ClinicalEngineering Directorate, Cardiff and Vale NHS Trust, under contract to the Medical Devices Agency.

• Enquiries to: Dr Diane Crawford, CEDAR, Cardiff Medicentre, University Hospital of Wales,Heath Park, Cardiff CF14 4UJ , Tel: 029 2068 2120, Fax: 029 2075 0239e-mail: [email protected]: www.imaging.uwcm.ac.uk/mpce/sctns/cedar/index

• Or: Mr Robert Allen, Programme Manager, Medical Devices Agency, Hannibal House,Elephant and Castle, London SE1 6TQ, Tel: 0207 972 8156, Fax: 0207 972 8105e-mail: [email protected]: www.medical-devices.gov.uk

We would like to thank all the manufacturers for loaning a sample free of charge for technicalassessment. We would also like to thank Dr Nicholas Cook and Dr Chris Hacking for their work on thisreport, prior to taking up their new positions.

HOW TO OBTAIN MDA EVALUATION REPORTSMDA Evaluation Reports are free of charge to NHS Trusts and Clinics

In EnglandMedical Devices AgencyRoom 1207,Hannibal HouseElephant & Castle,London SE1 6TQTel: 020 7972 8181

In ScotlandMr R StockHealth Planning & Quality DivisionScottish Executive,Health Department,St Andrew's House, Edinburgh,EH1 3DGTel: 0131 244 6913

In WalesMr J LewisNational Assembly forWales,HIMTE 3,Cathays ParkCardiff, CF10 3NQTel: 029 2082 3987

In Northern IrelandMr D CalfollaHealth Estates,Stoney Road,Dundonald, Belfast,BT16 OUSTel: 028 9052 3745

Copies may be obtained from the NHS Intranet site http://cymruweb.wales.nhs.uk/cedar/index.htm

DISTRIBUTION OF THIS REPORTThis report should be distributed to the following departments:

• Cardiology• Clinical Engineering / EBME• Day Theatres• Dentists• Dermatology• ENT• General Practitioners

• General Surgery• Gynaecology• Health Authority Libraries• Hospital Libraries• Medical Physics• Neurosurgery• Opthalmology

• Orthopaedics• Out-patient Departments• Paediatrics• Purchasing and Supplies• Scientific Officers• Theatre Staff

CROWN COPYRIGHT 2002Apart from any fair dealing for the purpose of research or private study, or criticism or review, as permitted under theCopyright, Design & Patents Act, 1988, this publication may only be reproduced, stored or transmitted in any form orby any means with the prior permission, in writing, of the Controller of Her Majesty’s Stationery Office (HMSO).Enquiries about reproduction should be made to the MDA

WHAT YOU CAN EXPECT FROM MDA EVALUATION REPORTSThe Device Evaluation Service (DES) aims to provide independent and objective evaluations of medicaldevices available on the UK market. Specialist centres, mainly in NHS Trusts, do the evaluations underlong-term contract to, and in accordance with protocols approved by, the MDA. The evaluations areusually of a unit supplied by the manufacturer. We would expect this unit to be representative of theproduct on the market but cannot guarantee this. Prospective purchasers should satisfy themselves withrespect to any modifications that might be made to the product type after MDA’s evaluation. The reportsare intended to supplement, not replace, information already available to prospective purchasers.

low / medium power electrosurgery review 2002 · electrosurgery (surgical diathermy) is a commonly...

Documents