pajunk MultiStim SWITCH User manual

MultiStim SWITCH and
MultiStim SENSOR –
Setting the trend in nerve stimulation
Plexus and Epidural Anaesthesia

The essential advantage regarding safety
MultiStim SENSOR and MultiStim SWITCH
With MultiStim SENSOR and MultiStim SWITCH,
PAJUNK®has founded a new generation of nerve
stimulators in regional anaesthesia.
Both devices offer a variety of functions for more
safety and efficiency, and are convincing due to
the following advantages:
The MultiStim SENSOR supports patient friendly,
percutaneous localization and identification of
nerves with the aid of a stimulation handle: the
PEG-electrode (Percutaneous Electronic Guidance)
- a fundamental distinctive feature in relation to
conventional stimulation devices.
Device type: BF
Battery: 9 V
Current intensity: max. 6 mApp / 60 mApp
Stimulation voltage: max. 65 Vpp
Stimulation frequency: 1 Hz, 2 Hz
Aside of a number of identical functions, the two devices are, however, different in the following functions:

- Large, clearly arranged display
- Analogous setting of the intensity of the
stimulation current by means of a notched
turning-knob
The essential advantage regarding safety
MultiStim SENSOR and MultiStim SWITCH
The MultiStim SWITCH has revolutionized nerve
stimulation through two outstanding innovations:
The new function indicating the patient
resistance permits the instant detection of
intraneural, intravascular and intrathecal cannula
placement, which can be corrected immediately.
- Integrated safety functions
- High-precision, microprocessor-controlled
adjustment of constant current
Device type: BF
Battery: 9 V
Current intensity: max. 6 mApp / 20 mApp
Stimulation voltage: max. 95 Vpp
Stimulation frequency: 1 Hz, 2 Hz
A switch-over function enables the anaesthe-
tist to either select the catheter or the cannula
for the stimulation by a simple keystroke. The
maximum current intensity will thereby corre-
spond with the distinct, varying requirements of
peripheral and epidural nerve stimulation.
Aside of a number of identical functions, the two devices are, however, different in the following functions:

While the exact insertion point is determined by means of anatomical landmarks when conventional
stimulation equipment is being used, the MultiStim SENSOR optionally also permits the location of the
puncture site with the aid of the PEG-electrode (Percutaneous Electrode Guidance).
Percutaneous nerve localization with handle
When using the PEG-electrode, the nerve is stimulated through the
skin without requiring a puncture, which will evoke a reflexive
response when the nerve is encountered.
The cannula is introduced at the insertion point identified by means
of this method, and the stimulation current is then switched over to
the cannula by keystroke. The placement of the cannula is perfor-
med in the usual manner.
Easy to view – simple in application
The MultiStim SENSOR
MultiStim SENSOR
Active output
Battery
condition
ON/OFF/Pause
SETUP-button
PEG-button
Nominal/actual current intensity
Pulse width
Pulse frequency
Pulse width
Pulse indicator

SETUP
The device has been provided with a SETUP-function. This function
permits the user himself to determine his individual initial parameters
for the percutaneous and invasive applications.
Adjustable stimulation pulse width
The stimulation pulse width can be adjusted fast and simple with a button of
its own in a number of steps – with intervals ranging from 0.05ms, 0.1ms,
0.2 ms, 0.3 ms, 0.5 ms to 1.0ms, e.g. for the selective stimulation of sensory
and motor nerve fibres in mixed nerves.
Easy to view – simple in application
The MultiStim SENSOR
PEG- and Cannula button*
Pressing the PEG- or Cannula button will cause the stimulation to be
switched to the handle or to the cannula, as may be required.
The respectively active electrode will thereby be indicated by means of a
corresponding status indicator in the display. The intensity and the
frequency of the stimulation current, as well as the pulse width can be
adjusted separately for both outputs. This button will remain without
function if no PEG-handle has been connected.
* only if the optional PEG-cable and electrode are used
Nominal/actual stimulation current intensity
The intensity of the stimulation current actually flowing through the patient
is measured constantly, and is indicated numerically as well as by bar graph
indicator on the display. The nominal and actual currents are also constantly
compared and indicated visually or acoustically, if the intensity of the
actually flowing current differs from the adjusted current intensity.
ON/OFF
PAUSE
The stimulation can be interrupted at any time with the PAUSE - button.
The settings of all stimulation parameters can be changed without emitting
impulses, while the device remains attached to the patient.
Pulse width
Pulse frequency
Pulse width

PAJUNK®MultiStim SWITCH can be used for the
location of peripheral nerves and also for epidural
stimulation. Its application is recommended for all
Switch-over key „CATH“ /
„Cannula“
SETUP
ON/OFF/PAUSE Pulse width
Turning-knob
Pulse width
Battery condition
Patient resistance
Current intensity
Actually flowing
current
NOMINAL/ACTUAL
current
Active output, for
example „Cannula“
MultiStim SWITCH
Brings the future of stimulation right to the point
purposes requiring the identification of nerves, bundle
of nerv fibers and nerve roots. With this device,
Pulse indicator
Pulse frequency

Pulse width
Turning-knob
Connector for the
stimulating catheter
Connector for
the cannula
Clamp for the adhesive electrode
The MultiStim SWITCH is
simultaneously connected
to the cannula and the
catheter by means of a
Y-patient cable.
MultiStim SWITCH
Brings the future of stimulation right to the point
PAJUNK®has set new standards in electrical nerve
stimulation, because for the first time ever, it
provides the option for alternative stimulation by
means of cannula or by stimulating catheter.
The MultiStim SWITCH is comparable with the
MultiStim SENSOR with respect to safety and
basic construction, and it has been furthermore
provided with additional functional utilities.
Pulse frequency

conductive tip
Muscle (Low impedance)
Muscle (Low impedance)
conductive tip
current current
Nerve (High impedance)
The MultiStim SWITCH has revolutionized nerve
stimulation. Because MultiStim SWITCH is the
first device, which permits the immediate
identification and correction of a misplaced
cannula, before mechanical or chemical injuries
The revolution in the nerve stimulation
More safety through the indication of pat ient resistance
are caused. Because it has been confirmed on the
basis of medical studies conducted under the
direction of Dr Tsui, that patient resistance will
increase distinctly in cases of intraneural, intravas-
cular and intrathecal punctures.
Nerve (High impedance)

5
0
10
15
20
25
30
35
touch nerve
penetrated inside nerve sheath
withdraw back out the
nerve sheath
The revolution in the nerve stimulation
More safety through the indication of pat ient resistance
Based on this knowledge, PAJUNK®has enhanced
the functional utilities of the MultiStim SWITCH
by adding a continuous indication of the patient
resistance by means of two analogous bar graphs.
The measurement of the resistance connected
therewith is only possible, if the highly precise
PAJUNK®stimulation cannula are used.
An individual threshold value can be predefined in advance for double safety by means of the
SETUP-button, which will cause an acoustic signal to be emitted if the threshold value is exceeded.
The MultiStim SWITCH therefore provides an essential advantage regarding safety for the patient.
L brachial R brachial L sciatic R sciatic
kΩ

Stimulation by cannula or catheter
The MultiStim SWITCH provides two alternative options for stimulation: by way of a
cannula or through a stimulating catheter. The corresponding switch-over is actuated
simply by pressing the CATH/Cannula – function key.
If stimulation by cannula is activated, then a cannula symbol will appear on the
display. The maximum stimulation current intensity will be 6 mA.
If stimulation by catheter is activated, then the word „CATH“ will appear on the
display. In the catheter-mode, the range of stimulation current intensity will be
increased to 20 mA, and will therefore correspond with the specific requirements of
epidural stimulation.
The intensity and the frequency of the stimulation current, as well as the pulse width
can be adjusted and configured separately at any time for both outputs (cannula and
catheter).
Maximum voltage and current intensity
The device emits a stimulation voltage of at most 95 Vpp in order to still obtain a good
stimulation effect on patients with high resistance conditions. The intensity of the
stimulation current for the catheter amounts to 20 mA for safety reasons, and is therefore
also suitable for epidural stimulation.
MultiStim SWITCH
Cannula symbol Catheter symbol
Useful options
The MultiStim SWITCH can do more
CATH
45 28
127
DE8012/M

mA
0,00
1,00
2,00
3,00
4,00
5,00
6,00
7,00
0102030405060
mA
MultiStim SWITCH
SETUP-button
Individual programming options differing from the manufacturer’s default
settings can be defined by actuation of the SETUP-button.
- Level 1: Volume of the warning- and monitoring sounds
- Level 2: Stimulation frequency, pulse width and current intensity in
the “Cannula-mode”
- Level 3: Stimulation frequency, pulse width and current intensity in
the “Catheter-mode”
- Level 4: Threshold value, at which the acoustic signal for the patient
resistance will change
- Level 5: Activation of the Choquet/Feugeas table; “Cannula-mode”
Individual definition of a constant pulse width
In the manual mode, stored as manufacturer’s default
setting, the pulse width can be defined by the user. It will
remain constant during the complete application. The
change of the current values is effected manually in fixed,
predefined steps, whereas these steps will be correspon-
dingly large at great distances to the nerve, and will
become smaller as the cannula approaches the nerve.
(see accompanying table)
Automatic adjustment of the current intensity
and impulse bandwidth according to the Choquet/
Feugeas table
In the automatic mode, the pulse width depends on the
intensity of the current, and has, on the basis of the
Choquet/Feugeas table, been stored permanently in the
nerve stimulator. The intention of this method is to
achieve a fast, efficient approach to the nerve, on the
basis of a constant charge. The device will correspondi-
ngly function with a great pulse width at the beginning,
which will be reduced according to the intensity of the
current in the course of approaching the target nerve.
This option ensures, that the anaesthetist can approach
the nerve in constant steps under continued muscular
response, and can therefore concentrate his full attention
completely on the puncture.
Constant
pulse width
Impulse bandwidth accor-
ding to Choquet/Feugeas
Clicks
Clicks
Stimulation pulse width
Stimulation pulse width

MultiStim SENSOR and MultiStim SWITCH
All the information at a glance
Nerve stimulator: MultiStim SWITCH
MultiStim SWITCH Item no.
incl. equipment case and SWITCH-cables for the
connection of cannula and StimuLong catheter
1151-94-40
SWITCH-cabel for the connection of stimulation
cannula and stimulating catheter
1151-94-07
MultiStim SENSOR
MultiStim SWITCH
MultiStim SENSOR Item no.
incl. equipment case and patient cables for the connection of stimulation cannula 1151-94-30
incl. equipment case, PEG-cable for the connection of stimulation cannula and monopolar handle 1151-94-32
Accessories
1) Patient cable for the connection of stimulation cannula 1151-94-13
2) PEG-cable for the connection of stimulation cannula and monopolar handle 1151-94-14
3) PEG-electrode - percutaneous, monopolar stimulation handle, autoclavable 1151-94-17
Extension cord for the connection of stimulation cannula, autoclavable*)01151-861F
Disposable extension cord for the connection of stimulation cannula, sterile*)01151-861Q
Nerve stimulator: MultiStim SENSOR
1)
Accessories:
2) 3)
XS200146A 07/10
*) Usable for SWITCH and SENSOR
PAJUNK GmbH
Medizintechnologie
Karl-Hall-Strasse 1
D-78187 Geisingen/Germany
Telefon [phone]
Telefax +49 (0) 77 04/92 91-6 00
www.pajunk.com

Peripheral – Epidural – Spinal
MultiStim SWITCH
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Table of contents
25 1. General information
25 2. Product specification/compatibility
25 2.1 Indication
25 2.2 Contraindications
25 2.3 Warnings and precautionary measures
28 2.4 Constant voltage or constant current
28 2.5 Accessories
29 3 Technical description
29 3.1 Technical data
30 3.2 Display
30 3.3 The control keys
30 3.4 The elements of the display
31 3.5 Menu structure setup
31 4. Operation
31 4.1 Pre-operational check
32 4.2 Operation of the nerve stimulator
33 4.3 PAUSE function
33 4.4 1 Hz/2 Hz mode
33 4.5 Mode cannula/KAN
33 4.6 Mode catheter CATH
33 4.7 Amplitude selection (setting of the nominal stimulation current)
34 4.8 Display modes for stimulation current
34 4.9 Display of the ACTUAL resistance, patient resistance
34 4.10 Indication of the battery condition
34 4.11 Adjustment of the stimulation impulse bandwidth
35 5 SETUP-functions
35 5.1.1 SETUP LEVEL 1: Volume control
35 5.1.2 SETUP LEVEL 2: Setting of the initial parameters for “Cannula mode”
36 5.1.3 SETUP LEVEL 3: Setting of the initial parameters for “Catheter mode”
36 5.1.4 SETUP LEVEL 4: Resistance indication with warning sound notification
37 5.1.5 SETUP LEVEL 5: Activation of the Choquet table KAN mode
37 5.1.5.1 MultiStim SWITCH Feugeaus/Choquet
38 6 Error messages
38 7 The battery
38 7.1 Battery replacement
39 8 Cleaning and disinfection of the device
39 9 Maintenance and technical safety checks
39 9.1 Technical safety checks
39 9.2 Device roster book in accordance with MPG
39 10 Accessories and spare parts list for MultiStim
39 11 Signal gradients, impulse patterns and power diagrams
40 11.1 Build-up and fall times
40 12 Notes, warnings
41 13 Electromagnetic compatibility (EMC)
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User Instruction – MultiStim SWITCH
1. General information
Please note: Due to US Medical Device Legislation and specific requirements for devices marketed in the
USA the wording of the user instructions for the US may slightly differ from the standard English version.
Please read the following information and instructions carefully.
The product may only be used by experienced medical staff in accordance with these instructions.
PAJUNK® GmbH Medizintechnologie does not give any recommendation for a method of treatment.
The treating medical specialist staff is responsible for the course and manner of application and the
selection of the patient.
Nonobservance or contravention of these instructions will cause the guarantee to expire and will lead
to endangering the safety of the patient.
If used in combination with further products, please always observe and comply with the directions for
use and the compatibility statements of these products.
Please check the product and the packaging for completeness, intactness and the status of sterility
before application. Do not use product if you have reason to doubt the completeness, the intactness
and the non hazardous status of sterility.
MultiStim SWITCH is intended to be used exclusively with PAJUNK® GmbH Medizintechnologie prod-
ucts (e.g. StimuLong catheters, UniPlex cannulae). The accessories may be connected with the device
exclusively by way of the enclosed equipment cable. Safe and successful functioning can only be
ensured with these products.
2. Product specification/compatibility
MultiStim SWITCH is delivered with the following basic equipment:
• MultiStim SWITCH nerve stimulator
• 9 volt block battery
• Patient main cable SWITCH
• Short-circuit plug
• Operating instructions
• Suitcase for storing SWITCH and accessories
Please observe by all means: The patient main cable of the MultiStim SWITCH is compatible with that
of the MultiStim SENSOR due to its technical design. Please make absolutely sure that the correct cable
is respectively used, since the device will otherwise not work as intended!
2.1 Indication
The MultiStim SWITCH serves for reliable neuro-localization, as for example in local- and regional
anesthesia (diagnostic, intra-operative and therapeutical block). It may be used for locating peripheral
nerves and also for epidural stimulation (Tsui-test). The PAJUNK® MultiStim SWITCH can be used in all
cases where the identification of nerves, of nerve fascicles or of nerve roots is required.
2.2 Contraindications
The use of a nerve stimulator on patients with known cardiac- or circulatory insufficiencies should be
considered carefully. Further contraindications may be caused by anatomical anomalies.
2.3 Warnings and precautionary measures
The connecting port of the stimulation cannula or the catheter adapter may only be connected to the
corresponding mating connector of the patient main cable. If an intermediate cable is used inbetween,
please also absolutely ensure correct connection here!
The device connector of the connector cable may only be connected to the nerve stimulator, and the
clip connection may only be connected to the adhesive electrode on the skin of the patient.
These plugs/connections may under no circumstances be brought into contact with live / current bear-
ing components (e.g. electrical outlets) or with metallic objects.
The MultiStim SWITCH may not be used in explosive surroundings to avoid gas explosions of anesthe-
sia gasses or the ignition of combustible liquids.
All connected facilities in the environment of the patient must comply with the applicable regula-
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tions to avoid injuring the patient. All facilities and accessories must comply with the regulations of
EN 60 601-1, EN 60 601-1-1, as well as with those of the applicable sub-norms. It is to be taken into
account, that in the most unfavorable case, all leakage currents or the auxiliary patient currents may
perhaps add up cumulatively and the patient may be endangered by these inadmissibly high values,
even if all the rules for the individual facilities have been complied with. It is therefore to be checked in
advance, whether the interconnection of the facilities will perhaps cause the permissive limiting values
to be exceeded. Improper interconnection of equipment and facilities (system formation) can injure the
patient vitally.
The patient himself may not come into contact with metallic objects which are earthed or which have
an electrically conductive connection with other facilities, or which permit capacitive coupling. That is
why we recommend the use of a sufficiently insulating/non-conductive, antistatic pad on the operating
table.
The MultiStim SWITCH may under no circumstances be operated with instruments and accessories
other than those which have been authorized, supplied or recommended by the manufacturer. Only
PAJUNK® accessories have been technically tested with regard to EMC (electromagnetic compatibil-
ity). Accessories of other vendors may lead to seriously harming the equipment- and system proper-
ties and may cause lasting impairment to the patient, the user or the equipment.
The simultaneous application of surgical RF-devices will evoke the acute risk of burns caused by touch-
ing the connections of the MultiStim SWITCH, the connector cable, the cannula tip or the adhesive
electrode. It is therefore necessary to disengage all connections to the MultiStim SWITCH and to
remove the stimulation cannula from the tissue before surgical RF-devices are used. The stimulation
cannula with its connector cable acts as an antenna for RF-energy, which may cause the induction
of a very high current density at the tip of the cannula. Nerve fibers in the vicinity may be irrevers-
ibly destroyed. The connected stimulator may simultaneously cause the rectification of the RF-energy,
which will lead to extremely high direct currents and voltage potentials at the electrodes. The direct
current stimulus emitted thereby can be very painful and may trigger intense, irreversible electrophysi-
ological reactions.
To avoid that poor contact of the adhesive electrode will lead to a malpositioning of the stimulation
cannula, please ensure that the adhesive electrode, which functions as a neutral electrode here, is in
sufficiently sound contact with a low tissue impedance. Fatty tissue, hair, uncleanness, repeatedly used
adhesive electrodes and electrodes of inferior quality can influence this tissue impedance adversely and
thereby evoke the risk of nerve damage. We therefore recommend, that the contact surface is selected
carefully: select only muscular areas with sufficient blood perfusion, and clean, shave and degrease the
skin. The position of the adhesive electrode should also not be too far away from the location of the
puncture. However, please avoid the thoracal application of the skin-electrode.
The MultiStim SWITCH should not be used on patients with implanted electrical devices (e.g. cardiac
pacemaker) without previously seeking corresponding medical advice from a specialist. Possibly occur-
ring disturbances of the implanted electrical devices through the stimulating current may constitute a
hazard for the patient. The attachment of electrodes in the vicinity of the thorax (rib cage, heart) may
increase the risk of ventricular fibrillation (cardiac fibrillation).
The stimulator may no longer be used if it displays a direct current- or perhaps a direct voltage-compo-
nent at the output, please send it in for repair.
The patient current should not fall below the following values: 0.15 mA invasive (catheter and cannula)
Operate the MultiStim SWITCH only with the genuine, CE-labeled PAJUNK®-accessories. All accessories
must be subjected to a visual inspection at regular intervals. The insulation of the patient lines may not
show any damage.
Use only high-quality, commercially available, CE-labeled single-use ECG-adhesive electrodes with pre-
gelled silver/silver chloride contacts. For optimal nerve stimulation, please use only electrodes which are
intact and have not dried out.
The adhesive electrodes may not be attached in the area of injuries.
When discarding the MultiStim SWITCH and the listed accessories, the users must comply with the
respective current regulations for the disposal of waste.
Special precautions apply for electric medical equipment with regard to EMC (electromagnetic com-
patibility). Portable and mobile RF-communication facilities may influence the MultiStim SWITCH. This
may lead to a malfunction of the device or of the system.
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Dynamic electrical- and dynamic magnetic interference fields may interact with the device and the system.
These interactions may have an influence on the measurement of the actual stimulus current, and in the
extreme case, they may lead to an error in indication and perhaps to a safety-shutdown of the device.
The MultiStim SWITCH may not be used near equipment emitting strong magnetic fields, e.g. radio-
telephones, surgical RF-devices, short wave- or microwave-therapy devices. Any potential introduction
of high-frequency currents into the stimulation cannula may lead to a damaging of the nerves.
The device may not be connected with other equipment. If the MultiStim SWITCH is operated nearby
to another device, then the devices or the system must be monitored and the correct functioning as
intended must be verified in this arrangement as it is being used.
Under unfavorable conditions, the MultiStim SWITCH may disturb other equipment in its function. We
therefore recommend to check all other equipment and facilities for compatibility with the MultiStim
SWITCH, and if necessary, to remove these from the patient.
The operation of other equipment or systems with the accessories may lead to increased emissions or
to reduced interference immunity of these systems. Please observe the enclosed EMC (electromagnetic
compatibility) information regarding installation, start-up and operation of the equipment or system
(see chapter Electromagnetic Compatibility (EMC)).
To avoid damaging the connector cable and the device, please do not hold or carry the device by its con-
nector cables or by its accessories. Do not wind the cable around the device or around other facilities.
The winding of the connector cable during normal operation of the stimulator will produce inductive
components and may, if very short stimulation pulses are being used, lead to a reduction of stimula-
tion performance or to faulty measurement of the actual stimulation current. Misinterpretations of the
reported values can be the consequence.
In case of battery leakage, the device should not be operated anymore for security reasons the device
must be returned to the manufacturer for proper cleaning.
Avoid unclean connections. Water and dirt will deteriorate the contact properties of the plug-in connec-
tions and lead to unintentional short-circuits or leakage-currents. These may lead to partial- or even total
diversion of the stimulation currents, which will cause the stimulation effect to decline, or even to fail
completely. In this case, the device cannot display the actually flowing patient current correctly any more.
To avoid damaging the MultiStim SWITCH and its accessories, do not use aggressive cleaning agents,
further details may be found under item “Cleaning and Disinfection of the Device”. Check all accesso-
ries in regular intervals. The insulation of the lines and hardware connections may show no damages.
The User Instructions are to be followed for the operation of the MultiStim SWITCH and the corre-
sponding accessories. When sterile accessories are being used, please always provide for sterile environ-
mental conditions.
Avoid unintentional bone contact with the stimulation cannula, since the cannula may thereby be
substantially damaged which may consequently cause a traumatization of the tissue.
Keep the accessories and MultiStim SWITCH away from live / current bearing objects. The electrostatic
and electromagnetic fields radiated therefrom may have an influence on the stimulation result, and
these themselves may even lead to unwanted stimulation effects in the tissue.
The device, the connector cables and the plugs must be kept completely clean and dry before and
during the application. Moisture and uncleanness will affect the function of the nerve stimulator and/or
the stimulation result.
Please note the position of metal implants in the tissue (e.g. plates or electrode cables). They may
perhaps conduct the stimulation signals to other locations and can cause detrimental effects there.
Implanted electronic equipment may be impaired by the stimulation current, which in turn will lead to
a malfunctioning of these implants or may even destroy them.
To avoid malfunctions of the MultiStim SWITCH, please check all functions before the intervention and
make sure that the accessories are suitable for the application. The accessories used must correspond to
safety class type BF.
To protect the patient from electrophysiological shock by electrostatic discharge (ESD), it is necessary to
wear corresponding clothing and to move about in an appropriately protected environment. An elec-
trostatic discharge (ESD) can cause extremely high current densities to appear at the tip of the cannula,
which can damage the surrounding tissue.
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Conformity with the following standards:
EN 60 601-1; 14971:2000; EN 60601-1-1; EN 60601-2-10; EN 60601-1-4
EN 60601-1-2; 13485:2003/ AC2007; 9001:2000; UL 60601; MPG; HWG, Directive 93-42-EC
2.4 Constant voltage or constant current
According to Ohm‘s law U⫽R⫻I, it is possible to use both, the voltage and the current intensity as the
quantity to be measured to determine the intensity (amplitude) of the electrical stimulus. The devices
are respectively referred to as voltage-constant or current-constant.
The electrical resistance (impedance) in the electrical circuit of a stimulation, which represents the
sum of skin-, tissue-, cannula-, electrode cable-resistance etc., will vary within wide ranges. It may vary
between < 1 k⍀and infinite. The factors skin humidity, conductivity of the skin and of the tissue and
the potential resistance of the adhesive electrode can hardly be influenced.
If the voltage (V) is selected as the measure for the intensity of the stimulus impulse, then currents may
appear during an application, which – in accordance with Ohm‘s law and depending on the resistance
– will differ by a manifold.
It is therefore better to use a nerve stimulator which permits the exact adjustment of the current inten-
sity (mA) between the two electrodes, the adhesive electrode (anode) and stimulation cannula (cath-
ode).
The stimulator with constant current setting must, however, be provided with a very high output
impedance – ideally infinite – so that the resistances which may perhaps occur in the external electri-
cal circuit will be negligible, and so that the actually flowing current will be indicated exactly on the
display.
Current-constant devices which permit the selection of the current intensity (mA) for the stimulus
impulse have gained acceptance within the last few years.
For the MultiStim SWITCH, the external load resistance can amount to as much as 12 k⍀. If this load
resistance is exceeded, then the actually flowing patient current (the actual stimulation current) can be
lower than the adjusted nominal stimulation current. In this case, the nominal stimulation current and
the actual stimulation current are indicated separately and visual and acoustic warning indications are
emitted. And the relevant impedance is continuously calculated and indicated on the LCD-display in
addition.
The MultiStim SWITCH is a precision instrument for the localization of nerve tracts in the human
organism. It was developed to stimulate nerve fibers in the living organism using cannulae and special
catheters for invasive stimulation which normally show a very high contact impedance, to be able to
determine the spatial position of these nerve fibers in relation to the tip of the electrode. The stimula-
tion cannulae are designed so that a local anesthetic can be injected in the proximity of the nerve fiber,
which will cause a reversible interruption of the conductive system.
2.5 Accessories
The MultiStim SWITCH can (unlike the model SENSOR) be exclusively connected with a patient cable
for cannula and catheter:
Yellow connection: CATHETER
White connection: CANNULA
Clamp for adhesive electrode
In addition patient main cable for cannula stimulation only is available:
White connection: CANNULA
Clamp for adhesive electrode
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There is an extension cable available for each, the connection to the cannula and to the catheter
(variant autoclavable and variant single use).
3 Technical description
The MultiStim SWITCH generates reproducible square pulses with adjustable frequency and continuo-
usly adjustable stimulation current. The adjustment range of the impulse current: 0.0 – 6.0 mA if stimu-
lation cannulae are being used, and 0,0 – 20 mA if stimulation catheters are being used.
The corresponding symbol will be shown synchronously with a short beeping sound in the
rhythm of the stimulus for visual and acoustic control.
If only the outer circle is visible, then the electrical stimulation circuit is not closed, i.e. there is no
stimulation current running through the patient.
If the circle is completely full, then the stimulation electrical circuit is closed, i.e. stimulation current
is running through the patient. The control sound will become more intensive in this case.
Due to a high stimulus voltage of max. 95 Vss , this renders an exceptionally large adjustment range for
extremely small stimulating electrodes.
Please make sure, that only CE-labeled adhesive electrodes are used for stimulation, which have been
provided with contact gel in order to keep the transition resistance as low as possible.
3.1 Technical data
Type: MultiStim SWITCH
Type of device BF
Battery: 9 V
Stimulating current: max. 20 mAss/
Resistance range 0 ⍀– 60 k⍀
Stimulation voltage: max. 95 Vss
Stimulation frequency: 1 Hz/2 Hz
Stimulation impulse bandwidth: 0,05 ms / 0,10 ms / 0,20 ms/
0,30 ms/0,50 ms/1,00 ms
Operating conditions: Temperature: 10°C – 30°C
Atmospheric humidity: 20% – 65%
Air pressure: n.a.
Transportation- and storage conditions: Temperature: 10°C – 30°C
Atmospheric humidity: 20% – 65%
Air pressure: n.a.
CE0123
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3.2 Display
Display, all indications activated (simulated condition)
MultiStim SWITCH has additionally been provided with a permanent analogous indication of the
patient resistance by means of two bar graphs below the digital.
3.3 The control keys
Button Function
Mode: CATH (catheter) or KAN (cannula, represented by symbol)
Access to the basic setting
„On“ / „Off“ / Pause
Selection of the impulse bandwidth
Mode: Impulse-frequency
3.4 The elements of the display
Symbol Meaning
Indicates must-current is displayed in mA
Indication of the electrical patient-circuit: Electric circuit not closed.
Indication of the electrical patient-circuit: Electrical circuit closed.
The value actually measured corresponds („⫽“) or („⬆“) does not correspond to the
nominal/set point value (inactive when no pulses are being emitted) (nominal current
= actual current)
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