Soring MBC-600, MBC-601 User manual

USERS MANUAL

	1
0
6
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C
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MONO	MONO	MONO		BIPO	BIPO	Sicherheit
						Safety
CUT	COAG1	COAG2		Cut	Coag
5		5	5
4		4	4
3		3	3
2		2	2
1		1	1
	F			MB C6 0 1
		1	2	Söring

MONO	MONO	BIPO	Sicherheit
CUT	COAG	COAG	Safety
5		5
4		4
3		3
2		2
1		1
F
		MB C 6 0 0
		Sör ing

27/04/04

© Söring

Users manual RF-units

Söring Inc	Söring GmbH
5009 Martin Luther King Jr. Freeway,	Medizintechnik
Fort Worth,	Justus von Liebig Ring 10
TX 76119	25451 Quickborn
Tel: [phone]	Tel: (+) 49 (0)4106-6100-0
Fax: [phone]	Fax: (+) 49 (0)4106-6100-10
E-mail: [e-mail]	E-mail: [e-mail]
	BH-MBC-USA 04/2004
	03-092 R3

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Users manual RF-units

Contents

1.	Introduction .................................................................................................................	5
2.	Important notes regarding the operation of RF Surgery units .........................	6
2.1. Operating of RF Surgery Equipment ................................................................................................		6
2.2. User instructions ...................................................................................................................................		6
2.3. Prescribed safety checks ....................................................................................................................		6
2.4. Medical Product Log Book ..................................................................................................................		6
2.5.How to keep the instruction manual and the medical product log book .................................		7
2.6. Accident and damage report ..............................................................................................................		7
2.7 Modifications and repairs.....................................................................................................................		7
3.	Physiological and physical fundamentals of RF Surgery ..................................	8
3.1. Heating effect of RF currents in biological tissue........................................................................		8
3.1.1 Reaction of biological tissue to local overheating ...........................................................................		9
3.2 Methods of RF Surgery and electrical Signal Shapes.................................................................		12
3.2.1 Cutting ...................................................................................................................................................		12
3.2.2. Coagulation .........................................................................................................................................		13
3.2.3. Electrodessication ..............................................................................................................................		13
3.2.5. Bipolar application technique ...........................................................................................................		14
3.2.5.1 Bipolar Automatic .........................................................................................................................................		14
4.	Patient safety.............................................................................................................	15
4.1. Patient placement ................................................................................................................................		15
4.2. Attachment of patient electrode ......................................................................................................		15
4.4. Current carrying cables .....................................................................................................................		18
4.5. Dangers from inflammable and explosive media. .......................................................................		19
4.6 Instructions for special applications...............................................................................................		19
Arrangement of Switches, Sockets and displays of MBC 601.........................................................		20
Arrangement of Switches, Sockets and displays of MBC 600.........................................................		21
5.1. Description of controls and indicators..........................................................................................		22
5.1.1 Description of the Safety Equipment ................................................................................................		27
5.2 Putting the equipment into operation .............................................................................................		28
5.2.1 Description of operational facilities ..................................................................................................		28
5.2.2 Preparation of equipment ...................................................................................................................		28
5.2.3 Switching on the equipment...............................................................................................................		28
5.2.4. Adjustment of function fields ............................................................................................................		29
6.	Accessories (extracts).............................................................................................	30
7.	Cleaning, maintenance, disinfection and sterilization .....................................	31
8.	Technical Data...........................................................................................................	32
9.	Technical safety checks ..........................................................................................	35

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9.1 Intervals...................................................................................................................................................	35
9.2 Extent .......................................................................................................................................................	35
9.3. Description of special checks ..........................................................................................................	35
9.3.1. Check of controls and indicators .....................................................................................................	35
9.3.2. Check of handpieces and footswitches ..........................................................................................	35
9.3.3. Check of RF generators and safety devices..................................................................................	36
9.3.4. Power measurement ..........................................................................................................................	36
9.3.5. Current Leakage test .........................................................................................................................	36
9.3.6. Test of handpiece allocation relay...................................................................................................	36
9.3.7. Test of patient electrode recognition ..............................................................................................	36
Remarks ..........................................................................................................................	37

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1. Introduction

This operating manual describes the function and handling of the Radio Frequency Surgery Equipment MBC. The manual serves as an instruction reference and should be read thoroughly before operating the equipment. Only then can the correct handling of the equipment be assured.

In case of incorrect handling no liability will be taken on by the manufacturer.

MBC's are RF surgery equipment conforming to DIN IEC 601 part 1, respectively EN60601-1 utilized only for rooms for medical use. Every important function is controlled and supervised by a microprocessor.

The MBC units, in MONOPOLAR MODE, are meant for the use in general surgery and gastroenterology. In MONOPOLAR MODE, operations on the heart, eyes and in the brain (neurosurgery) are not admissible!!!

This equipment has not been developed for continual operation (constant power supply for a longer period). The period for use fulfills the demands for operation of the EN60601-2-2 (10s load, 30s break).

This RF Surgery unit meets the requirements of the (EMC) guideline 93/42/EWG of the European

Community and is therefore labeled with the 0123 sign!

Before starting operation the appropriate handpieces must always be checked for external damage.

The Söring Company only accepts liability if accessories from the Accessories Order List were used!!!

At the end of the normal life cycle of the unit it should be taken to either a legitimate electronics disposal site or to the Söring Company.

Symbols Used

Patient electrode (when RF applied patient

Felectrodeelectrode insulated against earth)

!Attention!, see also covering documents

Off (separation from main power supply)

On (connection to main power supply)

type CF

CE label acc. To 93/42/EWG

0123

Defibrillator save

Monopolar Cutting & Coagulation

Bipolar Cutting1 and Coagulation

Potential equation pin

Attention high voltage

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Users manual RF-units

2. Important notes regarding the operation of RF Surgery units

During operation of RF surgery equipment disturbances of other electronic devices may occur due to generated interfering signals.

2.1. Operating of RF Surgery Equipment

The user is only allowed to operate such RF Surgery Equipment after the manufacturer or the distributor has:

1. Checked the equipment for faultless function at the location of operation and

2. Introduced the person responsible to the operation of equipment according to the instruction manual.

2.2. User instructions

RF Surgery equipment is only to be operated by persons, who have been introduced to the correct use of the equipment according to the instruction manual. Only people with sufficient knowledge of how to handle the equipment and practical experience are allowed to instruct others.

If such instruments are combined with additional equipment, the instruction of the operating personnel must be extended to the combination and its special functions.

2.3. Prescribed safety checks

The user of the RF Surgery unit must carry out the prescribed safety checks within the period stipulated and to the extent required. The extent and the periods for safety checks for RF equipment must be performed according to manufacturer's recommendations regarding extent and periods of inspections during servicing.

Safety checks of the technical protocols must be assigned only to those who have the appropriate education, the knowledge, and the experience gained during their practical work enabling them to carry out those checks accordingly. The safety check should be performed in a distraction free environment. If failures are found during safety checks, which may endanger patients, staff or third parties, the technician must immediately inform the authority responsible for the use of the instrumentation.

2.4. Medical Product Log Book

The supervising operator of RF Surgery units must keep a medical product log book. Other documentation is equivalent to the medical product log book, as long as it fulfills the requirements of the medical product log book to the same extent and is available for the user at any time.

The following entries are to be made in the medical product log book

1. Date and time of the function test before operating the equipment for the first time. 2. Date and time of instruction, as well as the names of the instructed persons.

3. Date and time of performing required safety checks and maintenance as well as the name of the person or the company performing these checks.

4. Date, time, kind, and consequences of failures and of re-occurring similar operation mistakes.

A copy of the CE certificate must be kept with the medical product log book.

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2.5.How to keep the instruction manual and the medical product log book

Instruction manuals and equipment books for RF surgery equipment must be kept, so that they are always accessible to persons commissioned to use the equipment.

The responsible authority may ask to look at these books at any time.

2.6. Accident and damage report

Function failures or breakdowns of medical equipment causing bodily injury must be reported immediately to the authority responsible.

The hospital must report the incident to the FDA and include all of the pertinent information as required by that agency. Suggested information to be gathered by the hospital includes the following:

1.What caused this event?

2.Was the equipment in proper operating condition

3.If repaired, does danger no longer exist.

4.Has new knowledge been gained which will make other or additional safety provisions necessary?

2.7Modifications and repairs

Modifications and repairs must not reduce the safety of the equipment and accessories for the patient, user, or the environment. Therefore, modifications and repairs to this equipment must only be carried out by the manufacturer or by persons explicitly authorized by Söring. If nonauthorized persons perform unqualified modifications and repairs to the equipment or accessories, the manufacturer will not accept liability. Furthermore in this case the warranty expires.

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3. Physiological and physical fundamentals of RF Surgery

Thermocautery as an aid to mechanical operation techniques began many years ago with the application of heated metal tools to wounds to control bleeding. The technique was found to be very effective. Later the use of electrical power to effect electro-cauterization and cutting of tissue was the next logical step. RF Surgery is the use of high frequency alternating electrical current (frequency higher then 300 kHz) with the purpose of alteration or destruction of cells and for cutting tissue. It is used for tissue removal and cauterization in connection with mechanical operation techniques. The tissue cauterization and cutting effects are accomplished by a combination of heating through the electrical resistance offered by the biological tissue and through the heating of the electrode.

3.1. Heating effect of RF currents in biological tissue

The heat production is mainly a result of the fact that biological tissue acts as an electrical resistor for frequencies normally used during RF surgery and that as an electrical resistor biological tissue heats up when electric currents flow through.

The amount of heat developed is therefore dependent on the current and the resistance of the conductor (the biological tissue) put up by the patient.

From the electrical point of view the patient is the conductor. The material of the conductor and its geometrical shape influences the resistance of this conductor. In this connection a comparison of specific resistance of metallic conductors and biological tissue is of interest. Table 3.1 clearly shows that the specific resistance of metals is much smaller than that of biological tissue. As a result, in a closed current loop of metallic conductors and biological tissue of equal cross sectional area the biological tissue heats up significantly more. As can be seen in the table below, different biological tissue types offer a wide range of electrical resistance and thus are affected differently by the applied RF signal. The MBC internal circuitry automatically senses the resistivity and adjusts the RF signal accordingly for the best results.

Biological Tissue	[Ω.cm]		Metal [Ω.cm]
(in the range 0.3 to	1 MHz)
blood	160	silver	0,0000016
muscle, kidney, heart	200	copper	0,0000017
liver, spleen	300	gold	0,0000022
lung	1000	aluminum	0,0000029
fat	3300

Table 3.1: Comparison of specific resistance of metals and biological tissue

The desired thermal effect should be accomplished within a small area in front of the active electrode. Conditions for RF heating are areas with small cross-sectional area and low electrical conductivity.

The actual temperature at the contact area between the active electrode and tissue results from the energy balance. The energy supplied is influenced by:

-Current per area (dependent on specific resistance of the tissue and the shape of the electrode).

-Effective time (the time that the RF current acts on the tissue area as determined by the electrode type and velocity of the electrode over the tissue).

-Current shape (full power, alternation of power, or changing power levels) The conducted heat is influenced by:

-The condition of the tissue, particularly at any given moment of the application cycle because the local thermal conductivity changes as tissues are destroyed.

-Temperature, because additional energy is needed for vaporization of tissue fluid.

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HF-Generator

RF-generator

Aktive-Elektrode active electrode

biologisches Gewebe biological tissue

Neutral-Elektrode

Patient electrode

Fig 3.1. Shows the principle of RF Surgery

3.1.1 Reaction of biological tissue to local overheating

If RF voltage (continuous sine signal) reaches a certain upper limit, an arc will occur at the contact zone of the active electrode to the tissue. This leads to a quick heating of the intercellular fluid. This vaporization of the intercellular fluid results in a bursting of the cells and the tissue looses its cohesion i.e., the electrode cuts.

Lower RF voltages (below 150veff) lead to a slower heating of the tissue, resulting in coagulation with no tissue separation.

Short RF impulses with high voltage lead to a build-up of sparks together with a strong surface coagulation.

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active electrode horny layer papilliary body

subcutaneous fatty tissue

musculature with connective tissue

vessel bone

Fig 3.2

Schematic representation of a melt-cut: Depending on the value of resistance of the different effected tissue the coagulation seam (the heat damage) is more or less widespread; broader at the horny layer than in the papillary body or the subcutis, even wider in the fatty tissue. In the musculature the heating effect melts deeper into the gaps of the connective tissue. Within a cut vessel the blood retracts and the intima is damaged from the different wall layers over a large area. In bones, the heating effect spreads along both sides of the periosteum and spreads only slowly deeper below the tip of the electrode.

If, however, the heat developed is extended to a larger area due to a larger contact surface between active electrode and tissue, boiling of the tissue fluids occurs together with widespread albumin coagulation. Depending on the used current intensity either depth coagulation (see Fig. 3.3) or a surface coagulation (see Fig. 3.4) with eschar generation is achieved. Due to bad thermal conductivity of eschar, heat transfer, especially into the depth, is prevented by eschar formation.

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active electrode

coagulated tissue

Fig. 3.3

Schematic representation of electro-coagulation on a homogenous tissue: The boiling extends to a depth somewhat larger than the diameter of the electrode. It is strongest underneath the electrode. At the surface it also extends to the surroundings of the electrode (rim effect).

active electrode		generated eschar

coagulated tissue

Fig. 3.4

Schematic representation of electro-coagulation with generated eschar: In this case the current value used for electro-coagulation is too high. Close to the electrode a coagulation of tissue is initiated so rapidly that eschar is created, the isolating effect of which prevents a deeper electro-coagulation. Due to eschar the electrode sticks to the tissue.

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Users manual RF-units

3.2 Methods of RF Surgery and electrical Signal Shapes

Cutting and coagulation modes of RF surgery depend in part on the shape of the sine wave of the electrical current. The frequency is remains around the 350 kHz range but the current amplitude (power) is changed to meet the surgical demands. A cutting current is a continuous sine wave. The amplitude is varied to accommodate the tissues being cut as each tissue type has a different electrical resistance. A coagulating current has a diminishing sine wave form repeated over intervals of time (parts of a second) and at varying sequence frequencies to achieve selected levels of coagulation. In the initial phase of a coagulation event the amplitude of the current is high and then falls to zero or almost so. If such a current could be heard it might resemble the sound of a ringing bell. See Figure ZZ.

3.2.1 Cutting

The cutting effect is based on the principle of cellular rupture. This is accomplished by a rapid and locally limited temperature rise causing an explosion-like vaporization of intra and extra cellular fluids, which ruptures cells and fractures cell connections. Under ideal conditions no coagulation occurs at the cut and the surfaces of the cut do not show the typical light color of a coagulation seam.

Principle of cell destruction

The shape of the electrode influences the cutting action and the kind of cut in electrotomy. Basically, cutting electrodes should have a tissue contact area as small as possible in order to obtain a high current density within a narrow space.

Loop or Ribbon Electrode

Knife or Lancet Electrode

Needle or Wire Electrode

Fig 3.5 Shapes of electrodes

Needle or wire electrodes are particularly useful for fine cuts where no or only minor coagulation is wanted. They present a very small tissue contact area allowing a high current density needed for fine cuts. With higher power the electrode will overheat and tissue will stick to it.

Knife or lancet electrodes resemble conventional scalpels with respect to their geometrical shape. The cutting action, however, is based on the above-mentioned principles and not on mechanical action. The leading edge of a knife has a small contact area where high current density can be produced for a fine cut, whereas, the broad sides of these electrodes achieve coagulation along the cut surfaces. Due to the relatively larger surface, compared with the needle electrode, more RF power is required. However the heating of these electrodes is lower due to their higher thermal capacity.

Loop and ribbon electrodes are mainly used for the cutting tissue by in slicing. A major application of this so called “hollow-cut“ is the TUR (Transurethral Resection) in urology. Further parameters which influence the quality of the cut are the cutting velocity, the condition of the tissue and the shape of the current.

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