VIO 300 S User Manual Ver 2.0x April 2010

VIO 300 S User Manual

Dr. Jürgen Forster Technical Editor Tel.: (+ 49) 70 71 75 52 46 E-mail: [email protected] I shall be very pleased if this User Manual can make your work easier and help you to use all the functions of your unit safely. It has been produced with great care by me in collaboration with development engineers and quality personnel. The use of publishing software and digital photography provided the documentation team with layout flexibility. Our object was to achieve a clear combination of text and photographs. The translation of the text into your language is subjected to a strict quality control. The User Manual is digitally printed only on delivery of your machine. All information is up to date. The ERBE documentation team would like to improve its products for your benefit, and I would therefore be very pleased to receive suggestions, criticism and questions as well as positive comments.

EN ISO 9001 EN ISO 13485 User Manual Art. No. 80113-601 Device Art. No. 10140-300 All rights to this User Manual, in particular rights of duplication, dissemination and translation, are reserved. No part of this User Manual may be reproduced in any form (by photocopying, microfilming or other methods) or processed, duplicated or disseminated by the use of electronic systems without the written consent of ERBE Elektromedizin GmbH. The information contained in this User Manual can be changed or expanded without prior notice and without obligation on the part of ERBE Elektromedizin GmbH. Printed by ERBE Elektromedizin Printed in Germany Copyright © ERBE Elektromedizin GmbH, Tübingen 2010

Table of Contents

Table of Contents

Chapter

80113-601 04/ 2010

1

Title

Page

Safety Instructions ... 9 Intended use ... 9 Combination with other equipment ... 9 Safety notations... 9 Meaning of the note ... 9 Who must read this User Manual?... 10 Compliance with safety information... 10 Structure of safety instructions ... 10 Operating errors by persons without training ... 11 Risks due to the environment... 11 Electric shock... 12 Fire / explosion ... 13 Burns ... 15 Risks due to incorrect use of the return electrode... 19 Defective unit... 20 Interference caused by the unit ... 21 Damage to the unit and accessories ... 22 Notes ... 23

2

Safety Features... 25 NESSY ... 25 How do I receive information about the safety status of the return electrode? ... 27 Automatic monitoring of equipment output error... 30 Automatic monitoring of the ON time... 30 Protection from operating errors ... 31

3

Accessories ... 33 Introduction... 33 VIO 300 S – example accessories... 34 Check compatibility of instrument and CUT / COAG mode ... 36 Check compatibility of the return electrode... 38 Compatible footswitches... 38

4

Description of the Controls ... 39 Controls on the front panel ... 39 Controls on the back ... 41

5

Working with the Electrosurgical Unit: a Tutorial ... 43 Re this chapter... 43 Setting options for the unit... 44 Factory unit settings ... 45

5 / 160

Table of Contents

Operation of the unit using Focus, Selection and Plus/Minus buttons...46 Connect unit and switch on ...50 Select/switch program ...51 Connect footswitches, instruments and return electrodes ...53 Using the unit (cutting/coagulation)...58 Change program settings ...61 Save program settings...68 Create new program ...71 Rename program ...72 Delete program ...74 Change setup settings (e.g. contrast and key volume)...75 Change service settings ...76 Procedure with errors shown on unit display ...77

6

Description of receptacle hardware... 79 Receptacles for different modes and instrument connectors ...79 Monopolar receptacle ...79 Bipolar receptacle...81 Receptacle for return electrode...82

Monopolar Modes... 83 AUTO CUT ...83 HIGH CUT ...85 DRY CUT...87 DRY CUT ° ...89 ENDO CUT Q ...91 ENDO CUT I...93 SOFT COAG ...94 SWIFT COAG...96 SWIFT COAG ° ...98 FORCED COAG ...100 SPRAY COAG...102 TWIN COAG ...104 CLASSIC COAG ...106

8

Bipolar Modes... 109 BIPOLAR CUT ...109 BIPOLAR SOFT COAG...111

9

APC receptacle (only available with the APC module) ... 115 APC receptacle ...115

10

APC Modes and Argon-Assisted Modes (only available with APC module) ... 117 FORCED APC...117 Argon-assisted AUTO CUT Mode ...119 Argon-assisted HIGH CUT Mode...121 Argon-assisted DRY CUT Mode ...123 Argon-assisted DRY CUT ° Mode...125 Argon-assisted SOFT COAG Mode ...127 Argon-assisted SWIFT COAG Mode ...129

6 / 160

80113-601 04/ 2010

7

Table of Contents

Argon-assisted SWIFT COAG ° Mode ... 131 Argon-assisted FORCED COAG Mode ... 133 Argon-assisted TWIN COAG Mode... 135

11

Installation ... 139 Ambient conditions ... 139 Electrical installation ... 140 Install electrosurgical unit on overhead support ... 142 Installing the unit on an ERBE equipment cart ... 143

12

Cleaning and Disinfection ... 145 Safety Instructions ... 145 Wipe disinfection ... 146 Instructions for cleaning and disinfection... 146

13

Status Messages, Error Messages ... 147 Status messages... 147 Operating error messages... 148 System error messages ... 149

14

General Technical Data... 151

15

Information on electromagnetic compatibility (EMC) ... 153

80113-601 04/ 2010

Guidelines for avoiding, recognizing and rectifying unwanted electromagnetic effects on other equipment or systems, which are the result of operating the VIO system. ... 153

16

Maintenance, Customer Service, Warranty, Disposal ... 159 Maintenance ... 159 Customer service... 159 Warranty... 159 Disposal... 160

7 / 160

80113-601 04/ 2010

Table of Contents

8 / 160

1 • Safety Instructions

CHAPTER 1

Safety Instructions

Intended use The VIO 300 S is an electrosurgical unit for cutting and coagulation. Thanks to its performance features it offers universal applications.

Combination with other equipment You can combine this unit with matching ERBE equipment: e.g. APC 2, EIP 2. You will then have a well-conceived, coordinated system.

Safety notations

DANGER indicates an imminently hazardous situation which, if not avoided, will result in death or serious injury.

WARNING

80113-601 04/ 2010

indicates a potentially hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION indicates a potentially hazardous situation which, if not avoided, may result in minor or moderate injury.

CAUTION used without the safety alert symbol indicates a potentially hazardous situation which, if not avoided, may result in property damage.

Meaning of the note "Note:" Refers a) to manufacturer's information that relates directly or indirectly to the safety of people or protection of property. The information does not relate directly to a risk or dangerous situation. Refers b) to manufacturer's information that is important or useful for operating or servicing the unit.

9 / 160

1 • Safety Instructions

Who must read this User Manual? Knowledge of the User Manual is absolutely essential for correct operation of the unit. Therefore, everyone who is concerned with •

preparing,

•

adjusting,

•

operating,

•

disassembling, as well as

•

cleaning and disinfecting

the unit must read the User Manual. Please pay particular attention to the safety instructions in each chapter.

Compliance with safety information Working with medical equipment is associated with certain risks to patients, medical personnel and the environment. Risks cannot be entirely eliminated by design measures alone. Safety does not depend solely on the equipment. Safety depends to a large extent on the training of medical personnel and correct operation of the equipment. The safety instructions in this chapter must be read, understood and applied by everyone who is working with the equipment.

The safety instructions are structured according to the following risks:

10 / 160

•

Operating errors by persons without training

•

Risks due to the environment

•

Electric shock

•

Fire / explosion

•

Burns

•

Risks due to incorrect use of the return electrode

•

Defective unit

•

Interference caused by the unit

•

Damage to the unit and accessories

•

Notes

80113-601 04/ 2010

Structure of safety instructions

1 • Safety Instructions

Operating errors by persons without training

WARNING Operating errors by persons without training

Persons without training can operate the unit incorrectly. Risk of injury or death for patients and medical staff! Risk of damage to property. ¨ The equipment may only be used by persons who have been trained on how to use it properly according to this User Manual. ¨ Training may only be carried out by persons who are suitable on the basis of their knowledge and practical experience. ¨ In the event of uncertainties or if you have any questions, please contact ERBE Elektromedizin. You will find the addresses in the address list at the end of this User Manual.

Risks due to the environment

CAUTION Interference with the unit by portable and mobile HF communication devices (e.g. mobile phones, WLAN equipment)

Electromagnetic waves emitted by portable and mobile HF communication devices can effect the unit.

80113-601 04/ 2010

The unit may fail or not perform properly. ¨ Please see the table "Recommended separation distances between portable and mobile HF communications equipment and the equipment" at the end of this User Manual.

CAUTION Unsuitable temperature or level of humidity during operation

If you operate the equipment at an unsuitable temperature or level of humidity, it may sustain damage, fail, or not perform properly. ¨ Operate the equipment at a suitable temperature and level of humidity. You will find the tolerances for temperature and humidity in the Technical Data. ¨ If other ambient conditions must be observed for operation of the equipment, you will also find them in the Technical Data.

CAUTION Unsuitable temperature or humidity in transit or storage

If you transport or store the equipment at an unsuitable temperature or level of humidity, it may sustain damage and fail. ¨ Transport and store the equipment at a suitable temperature and level of humidity. You will find the tolerances for temperature and humidity in the Technical Data. ¨ If other ambient conditions must be observed for transport and storage of the equipment, you will also find them in the Technical Data.

11 / 160

1 • Safety Instructions

CAUTION Insufficient acclimatization time, unsuitable temperature during acclimatization

If the device was stored or transported below or above a certain temperature, it will take a certain time and temperature to acclimatize. If you do not observe the rules, the device can sustain damage and fail. ¨ Acclimatize the device according to the rules in the Technical Data.

CAUTION Overheating of the device due to poor ventilation

If ventilation is poor, the device can overheat, sustain damage, and fail. ¨ Install the device in such a way that there is an unobstructed circulation of air around the housing. Installation in confined wall recesses is prohibited.

CAUTION Penetration of liquid into the device

The housing is not absolutely watertight. If liquid penetrates, the device can sustain damage and fail. ¨ Make sure no liquid can penetrate the device. 80113-601 04/ 2010

¨ Do not place vessels containing liquids on top of the device.

Electric shock

WARNING Defective grounded power outlet, inferior-quality power cord, incorrect line voltage, multiple power outlets, extension cords

Risk of electric shock and other injuries to the patient and medical personnel! Risk of damage to property. ¨ Connect the unit / the equipment cart to a properly installed grounded power outlet. ¨ Only use the ERBE power cord or an equivalent power cord for this purpose. The power cord must bear the applicable national test symbol. ¨ Check the power cord for damage. You must not use a damaged power cord. ¨ The supply voltage must match the voltage specified on the unit's rating plate. ¨ Do not use multiple power outlets. ¨ Do not use extension cords.

12 / 160

1 • Safety Instructions

WARNING Incorrect line fuse, defective device

Risk of electric shock to the patient and medical personnel! Risk of damage to property. ¨ Blown line fuses may only be replaced by a competent technician. Only replacement fuses that have the same rating as the one specified on the unit’s rating plate may be used. ¨ When a fuse has been changed, the function of the unit must be verified. If the unit does not function properly or if there are any concerns, please contact ERBE.

WARNING Connection of unit / equipment cart and power supply during cleaning and disinfection

Risk of electric shock to the medical personnel! ¨ Switch off the device. Unplug the power cord of the device/ equipment cart.

Fire / explosion In electrosurgery electric sparks and arcs occur at the instrument. Flammable gases, vapors, and liquids can be set alight or caused to explode.

DANGER 80113-601 04/ 2010

Flammable anesthetics

Risk of explosion to the patient and medical personnel! Risk of damage to property. ¨ Do not use flammable anesthetics when an operation is being performed on the head or thorax. ¨ If use is unavoidable, you must extract the anesthetics before performing electrosurgery.

WARNING Flammable gas mixture in TUR (Transurethral Resection) and TCR (Transcervical Endometrial Resection)

Hydrogen and oxygen can ascend into the roof of the bladder, the upper part of the prostate, and the upper part of the uterus. If you resect into this gas mixture, it could combust. Risk of combustion to the patient! ¨ Allow the gas mixture to escape through the resectoscope sheath. ¨ Do not resect into the gas mixture.

DANGER Flammable endogenous gases in the gastrointestinal tract

Risk of explosion to the patient! ¨ Extract the gases before performing electrosurgery or irrigate with CO2.

13 / 160

1 • Safety Instructions

DANGER Combustion-supporting gases, e.g. oxygen, nitrous oxide

The gases can accumulate in materials like cotton wool or gauze. The materials become highly flammable. Risk of fire to the patient and medical personnel! Risk of damage to property. ¨ Do not use combustion-supporting gases when an operation is being performed on the head or thorax. ¨ If use is unavoidable, you must extract the combustion-supporting gases before performing electrosurgery. ¨ Remove any jeopardized (e.g. cotton wool or gauze) materials before performing electrosurgery. ¨ Check the oxygen-carrying tubes and connections for leaks. ¨ Check the endotracheal tubes and their cuffs for leaks. ¨ Before using argon plasma coagulation (APC) in the tracheobronchial system it is absolutely essential that you observe the specific safety information and instructions in the User Manual for the argon plasma unit!

WARNING Active or hot instruments in contact with combustible materials

Materials like gauze, swabs, and cloths can catch fire.

¨ Do not bring active or hot instruments into contact with combustible materials. ¨ Put instruments down in a safe place: sterile, dry, non-conductive, and easy to see. Instruments that have been put down must not come into contact with the patient, medical personnel, or combustible materials.

WARNING Flammable detergents and disinfectants, flammable solvents in adhesives used on the patient and on the device / equipment cart

Risk of fire and explosion to the patient and medical personnel! Risk of damage to property. ¨ Use products that are not flammable. If the use of flammable products is unavoidable, proceed as follows: ¨ Allow the products to evaporate completely before switching on the device. ¨ Check whether flammable liquids have accumulated under the patient, in body recesses such as the navel, or in body cavities such as the vagina. Remove any liquids before performing electrosurgery.

14 / 160

80113-601 04/ 2010

Risk of fire to the patient and medical personnel! Risk of damage to property.

1 • Safety Instructions

WARNING Ignition of anesthetics, skin cleansers, and disinfectants in potentially explosive atmospheres

If you place the device in a potentially explosive atmosphere, anesthetics, skin cleansers, and disinfectants can ignite. Risk of fire and explosion to the patient and medical personnel! Risk of damage to property. ¨ Do not place the device in potentially explosive atmospheres.

Burns

WARNING Damaged device, damaged accessories, modified device, and modified accessories

Risk of burns and injury to the patient and medical personnel! Risk of damage to property. ¨ Check the device and accessories for damage every time before using them (e.g. footswitch, cords of instruments and the return electrode, equipment cart). ¨ You must not use damaged equipment or damaged accessories. Replace defective accessories. ¨ If the unit or accessories are damaged, please contact our customer service.

80113-601 04/ 2010

¨ For your safety and that of the patient: Never attempt to perform repairs or make modifications yourself. Any modification will invalidate liability on the part of ERBE Elektromedizin GmbH.

WARNING HF leakage current flows through metal parts

The patient must not have contact with electrically conductive objects. That includes metal parts of the operating table, for example. HF current can be discharged through points of contact accidentally (HF leakage current). Risk of burns to the patient! ¨ Position the patient on dry, antistatic drapes. ¨ If the drapes can become wet during the operation due to sweat, blood, irrigation liquid, urine, etc., lay a waterproof sheet over the drapes.

WARNING HF leakage current flows through monitoring electrodes

HF current can be discharged through points of contact between the skin and monitoring electrodes accidentally (HF leakage current). Risk of burns to the patient! ¨ Position monitoring electrodes as far away as possible from the surgical field (area where electrosurgical instruments are used). ¨ Do not use needle electrodes for monitoring during electrosurgery. ¨ Where possible, use monitoring electrodes that contain devices to limit high-frequency current.

15 / 160

1 • Safety Instructions

WARNING HF leakage current flows through skin-to-skin points of contact

HF current can be discharged through skin-to-skin points of contact accidentally (HF leakage current). Risk of burns to the patient! ¨ Prevent skin-to-skin points of contact. For example, lay dry gauze between the patient's arms and body.

WARNING Unintentional activation of the instrument

Risk of burns to the patient and medical personnel! ¨ Put instruments down in a safe place: sterile, dry, non-conductive, and easy to see. Instruments that have been put down must not come into contact with the patient, medical personnel, or combustible materials. ¨ Instruments that have been put down must not come into contact with the patient, not even indirectly. An instrument can come into contact with the patient indirectly through electrically conductive objects or wet drapes, for example.

CAUTION Hot instruments

¨ Put instruments down in a safe place: sterile, dry, non-conductive, and easy to see. Instruments that have been put down must not come into contact with the patient, medical personnel, or combustible materials. ¨ Instruments that have been put down must not come into contact with the patient, not even indirectly. An instrument can come into contact with the patient indirectly through electrically conductive objects or wet drapes, for example.

WARNING Unintentional activation of the instrument during an endoscopic application

If the instrument is activated and remains activated during an endoscopic application, the patient can suffer burns when the instrument is removed. All points that come into contact with the active part of the instrument are at risk. The cause of unintentional activation can be a fault in the footswitch or device or operator error, for example. You will recognize unintentional activation from the continuous activation signal. Risk of burns to the patient! ¨ Turn off the power switch on the electrosurgical unit immediately. Only then should the instrument be removed from the patient’s body.

16 / 160

80113-601 04/ 2010

Even non-active instruments that are still hot can burn the patient or medical personnel.

1 • Safety Instructions

WARNING Capacitive coupling between the cords of two instruments

When one instrument is activated, current can be transferred to the cord of another instrument (capacitive coupling). The patient can suffer burns if the non-active but still live instrument has direct or indirect contact with the patient. Risk of burns to the patient! ¨ Lay the cords of instruments in such a way that they are as far apart as possible. ¨ Put instruments down in a safe place: sterile, dry, non-conductive, and easy to see. ¨ Instruments that have been put down must not come into contact with the patient, medical personnel, or combustible materials. ¨ Instruments that have been put down must not come into contact with the patient, not even indirectly. An instrument can come into contact with the patient indirectly through electrically conductive objects or wet drapes, for example.

WARNING Power setting too high, ON time too long, effects too high

The higher the power setting the longer the ON time of the unit and the higher the effect the higher the risk of accidental tissue damage.

80113-601 04/ 2010

Risk of accidental tissue damage to the patient! ¨ Set power as low as possible relative to the required surgical effect. However, power settings that are too low can be dangerous, e.g. gas embolisms with the APC (Argon Plasma Coagulation). ¨ Activate the unit for as short a time as possible relative to the required surgical effect. ¨ The temperature at the return electrode site increases during long and continuous activations; therefore, ensure that the cooling phases between activations are sufficient. ¨ Set effect as low as possible relative to the required surgical effect. ¨ If you are unable to achieve a surgical effect with a power setting / ON time / effect level that is sufficient judging from experience, this can be due to a problem with the electrosurgical unit or accessories: ¨ Check the instrument for soiling with insulating tissue remnants. ¨ Check the return electrode to make sure it is secure. ¨ Check the connectors on all cords to make sure they are secure.

WARNING Activation of the unit with no knowledge of active settings

If the user does not understand the active settings of the unit, he can cause the patient accidental tissue damage. ¨ Check the active settings on the display of the unit, after: switching on the unit, connecting up an instrument, and changing the program.

17 / 160

1 • Safety Instructions

WARNING The user was not informed of a change in maximum ON time

Risk of accidental tissue damage to the patient! ¨ All users must be informed of any change in maximum ON time at an early stage. That is, before the user works with the modified maximum ON time for the first time. ¨ The temperature at the return electrode site increases during long and continuous activations; therefore, ensure that the cooling phases between activations are sufficient.

WARNING Tissue structures / vessels with a cross-section that is small or becoming smaller

If monopolar HF current flows through parts of the body with a relatively small cross-section, there is a risk of unintentional coagulation for the patient! ¨ If possible, use the bipolar coagulation technique.

WARNING Activation signal not audible

You do not hear the signal when the electrosurgical unit is activated. Risk of burns to the patient and medical personnel!

WARNING Undesirable contact between the active instrument and metal objects in the patient's body

Contact with metal hemostats, etc. Risk of burns to the patient! ¨ Do not touch metal objects (e.g. implants) in the patient's body with the active instrument.

CAUTION A hand-held metal instrument is touched with the active instrument (electrode)

Risk of hand burns! ¨ Such practice is not recommended. The risk of burns cannot be ruled out.

18 / 160

80113-601 04/ 2010

¨ Adjust the activation signal so that it is clearly audible.

1 • Safety Instructions

Risks due to incorrect use of the return electrode

CAUTION Non-compatible or single surface return electrode

When applying a non-compatible return electrode, it should be expected that monitoring the contact between return electrode and skin is faulty. When applying a single surface return electrode, the contact between return electrode and skin is not monitored. If contact between return electrode and skin is inadequate, the unit does not emit any visual and acoustic signal. Risk of burns for the patient under the return electrode! ¨ Check in the accompanying papers of the manufacturer whether the return electrode is suitable for the VIO device used. ¨ Use only suitable return electrodes. ¨ When applying a single surface return electrode: Regularly check the return electrode for good skin contact. ¨ Check in the accompanying papers of the manufacturer whether the return electrode cable is suitable for the return electrode used. ¨ Use only suitable return electrode cables.

WARNING Positioning the return electrode above the heart

80113-601 04/ 2010

Risk of ventricular fibrillation and cardiac arrest for the patient! ¨ Do not position the return electrode over the heart or in the region of the heart.

CAUTION Incorrect application of the return electrode

Risk of burns to the patient! ¨ Apply the entire contact surface of the return electrode to a muscular part of the body with good blood circulation. ¨ Apply the return electrode as close as possible to the surgical site. ¨ Insert the contact tab of the return electrode completely into the connecting clamp. The contact tab must not touch the patient's skin. (For reusable cord with disposable pads only.) ¨ Align the symmetry line of the return electrode towards the operating field. The current should flow from the active electrode (instrument) to the symmetry line of the return electrode (see following figure). ¨ Check the return electrode regularly for good contact with the patient's skin. ¨ Check the return electrode especially when the patient has been repositioned and after surgical steps where the device was activated frequently and for a long time.

19 / 160

1 • Safety Instructions

Fig. 1-1

CAUTION Short circuit in the connecting cord or in the clip of a dual surface return electrode

With the NESSY setting "NE: either way" setup and a short circuit in the connecting cord or in the clip of a dual surface return electrode the device can no longer monitor the contact with the patient's skin or the application direction of the contact surface. You will not receive a warning if the electrodes becomes detached from the skin. You will not receive a warning if the application direction of the return electrode is incorrect. Risk of burns to the patient!

Note: ERBE recommends the use of split return electrodes in combination with the NESSY setting set to “NE: dynamic” or “NE: dual surface”. With this combination the optimal use of the safety monitoring functions are given (see chapter 2 “NESSY Safety Features). If the unit is activated in a monopolar mode using a cable with a short, the unit will give an audible warning signal and will display a "B-B" error message on the screen.

Defective unit

WARNING Undesirable rise in output level due to failure of electrosurgical unit

Risk of accidental tissue damage to the patient! ¨ The device shuts off independently. ¨ To guard against a possible failure of the electrosurgical unit, have the device checked for safety at least once a year.

WARNING Routine safety testing not being done

Risk of injury or death for patients and medical staff! Risk of damage to property. ¨ Have the device checked for safety at least once a year. ¨ You must not use a device that is not safe.

20 / 160

80113-601 04/ 2010

¨ To rule out the possibility of a short circuit in the connecting cord and the clip before use, see Chapter 2 of this Manual "Safety Features" for NESSY.

1 • Safety Instructions

WARNING Failure of display elements

If display elements fail, you can no longer operate the device safely. Risk of injury or death for patients and medical staff! ¨ You must not use the unit.

Interference caused by the unit

WARNING Interference with cardiac pacemakers, internal defibrillators, or other active implants

Activation of the electrosurgical unit may affect the performance of active implants or damage them. Risk of injury or death for patients! ¨ In the case of patients having active implants, consult the manufacturer of the implant or the competent department of your hospital prior to performing surgery. ¨ Do not position the return electrode near cardiac pacemakers, internal defibrillators, or other active implants.

CAUTION Interference with electronic equipment due to the electrosurgical unit

80113-601 04/ 2010

The activated electrosurgical unit can affect the performance of electronic equipment by causing interference. The equipment may fail or not perform properly. ¨ Position the electrosurgical unit, the cords of the instruments, and the cord of the return electrode as far away as possible from electronic equipment. ¨ Position the cords as far away as possible from the cords of electronic equipment.

WARNING Low-frequency currents stimulate nerves and muscles (Neuromuscular Stimulation)

Low-frequency currents arise either due to low-frequency power sources or partial rectification of the HF current. During cutting procedures, forced coagulation and spray coagulation, the unavoidable electric arcs between an active electrode and the tissue have the effect that a portion of the high-frequency alternating current is rectified. Spasms or muscle contractions can occur. Risk of injury to the patient. ¨ Set effect as low as possible relative to the required surgical effect.

21 / 160