B. Braun Stimuplex HNS 12 User manual

Stimuplex®HNS 12
Nerve Stimulator
for Peripheral Regional Anesthesia
User Manual
GB

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In the US:
Stockert GmbH B. Braun Melsungen AG B. Braun Medical Inc.
Bötzinger Strasse 72 Hospital Care Division 824 Twelfth Avenue
79111 Freiburg 34209 Melsungen Bethlehem, PA 18018-3524, USA
Germany Germany Phone: [phone]
Phone: [phone] Phone: [phone] Fax: [phone]
Fax: [phone] Fax: [phone] Email: [e-mail]
Email: [email protected] Email: [email protected] http://www.bbraunusa.com
http://www.stockert.de http://www.bbraun.com
The Stimuplex®HNS 12 may only be used in applications for which this
product is intended.
Federal (US) law restricts this device to sale by or on the order of a physician.
Meliseptol®, Stimuplex®and Contiplex®are registered trademarks of B. Braun
Melsungen AG

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Contents
1. Principles of Peripheral Electrical Nerve Stimulation 7
1.1. Area of Application 7
1.2. Intended Use 9
1.3. Indications 9
1.4. Contraindications 9
1.5. Warnings 10
1.6. Constant voltage or constant current 17
2. Description of the Device 18
2.1. Checks before Start-up 20
2.2. Technical Description 23
2.2.1. Plug Connections 24
2.2.2. Current regulator (dial) and keys 24
2.2.3. Sound 26
2.2.4. LED 26
2.2.5. Display modes 27
2.2.6. Menu structure 29
3. Operation of the Stimuplex®HNS 12 32
3.1. Stand-by 32
3.2. Selecting the current adjustment range 33
3.3. Selecting the stimulation current 34
3.4. Selecting the stimulus duration 34
3.5. Selecting the stimulation frequency 37
3.6. Current threshold display 37
3.7. Checking the battery voltage 38
3.8. Additional information – Menu info 38
4. Setting parameters and options for future switch-on procedures 39
4.1. Setting switch-on values for stimulation parameters 39

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4.1.1. Current adjustment range 39
4.1.2. Stimulus duration 40
4.1.3. Frequency 40
4.1.4. Current threshold display 40
4.2. Setup 41
4.2.1. Tone 41
4.2.2. Dial turns 41
4.2.3. Contrast on the LCD display 42
4.2.4. Automatic switch off 42
4.2.5. Date and time 42
4.2.6. Language 43
4.2.7. Options 43
5. Initial setup, maintenance and notes 46
5.1. Testing the Stimuplex®HNS 12 46
5.2. Special technical features 47
5.3. Technical data 48
5.4. Battery 49
5.5. Cleaning and disinfecting the Stimuplex®HNS 12 50
5.6. Maintenance and safety checks 50
5.7. Equipment logbook (Specific requirement for use on German market) 51
5.8. Notices 51
5.9. Error messages 52
5.10. Instruments and accessories 56
6. References 60
7. Appendix 61
8. Symbols on Stimuplex®HNS 12 67
9. Electromagnetic compatibility (EMC) 70

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10. Specific requirements for the US market 75
10.1. Addition to Section “5.6. Maintenance and safety checks” of the Manual 75

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Preface
With your purchase of the Stimuplex®HNS 12 nerve stimulator, you have acquired a device
that is easy to operate and provides you with a straightforward array of all the functions you
need to perform peripheral nerve blocks.
The following chapters describe the operation of Stimuplex®HNS 12.
The use of the stimulation needles required for performing stimulation is described in the
instructions for use accompanying the needles, which are not part of this user manual.
Chapter 1 describes the basic functions of unipolar nerve stimulation including a discussion
of the principle of constant current stimulation.
For your study of its operational fundamentals, we recommend that you have a
Stimuplex®HNS 12 with all of its accessories at hand and functional so that you can learn
about the functions in practical exercises.
It is helpful to simulate the patient with a wet paper tissue or a small sponge soaked in
saltwater. The saline solution is required to produce electrical conductivity.
The device may only be operated in compliance with the user manual.
The device may only be used in professional environments (e.g. hospital).
If you have further questions, the people at B. Braun Melsungen AG and STOCKERT GmbH
are happy to be at your service.
Yours,
B. Braun Melsungen AG
STOCKERT GmbH

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1. Principles of Peripheral Electrical Nerve Stimulation
1.1. Area of Application
Peripheral nerve stimulation facilitates the performance of peripheral nerve and plexus
blocks. The user no longer needs to rely on feedback from the patient about paresthetic
sensations. The danger of mechanical nerve lesions is mostly eliminated.
When the stimulation needle is placed sufficiently close to the target nerve, predefined elec-
trical pulses generate muscle contractions at motor efferent fibers and electrically elicited
paresthesias at sensory afferent fibers. During this procedure, direct contact of the injection
needle with the nerve is intentionally avoided.
The Stimuplex®HNS 12 nerve stimulator shall be used only by medical personnel trained
and experienced in the techniques of peripheral nerve stimulation and only in the clinical
environment (not in home care environment).
Since peripheral electrical nerve stimulation (PNS) is no substitute for the
anatomical knowledge required to perform regional anesthesia, accurate
knowledge of the topography and nerve distribution area is a prerequisite.
Advantages of nerve stimulation:
•Objective muscle response is obtained without the user having to rely on information
or cooperation from the patient
•No direct needle-nerve contact, no painful paresthesias, no mechanical nerve lesions,
and no intraneural injections.

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Permissible and possible options:
•Sedation and analgesia prior to blockade depending upon the patient’s needs
•General anesthesia prior to blockade
•Blockades distal to the previous site of a regional anesthesia procedure in anesthe-
tized or partially anesthetized regions
•Extension of the indication spectrum
•Enhancement of safety standards
The resting potential at the nerve membrane is around 80 mV. The cell’s interior is negatively
charged compared to the surrounding medium. Sufficiently large ion movement reduces the
membrane potential to 55 mV, making the membrane freely permeable and generating an
action potential.
The various types of nerve fiber differ with regard to their sensitivity to electrical stimula-
tion. The A-alpha motor fibers have the shortest chronaxia (50-100 µs). The afferent fibers
that transmit pain sensation (Aδand C-fibers) require a longer pulse (150 and/or 400 µs) at
a minimum current. Mixed peripheral nerves can be localized using short pulses (0.10 ms)
without triggering pain sensations. For pure sensory nerves, a longer pulse is recommended
(0.30 ms, 0.50 ms or 1.00 ms).
Whenunipolarneedles(insulatedandwithconductivetip)areused,thecurrentnecessaryto
trigger muscular contractions (= pulse amplitude) correlates with the distance from the tip
of the needle to the nerve. The lower the current, the more accurately the target nerve can
be localized. This allows quicker onset and ensures a more reliable success of the blockade.
Nevertheless, it is important to observe and stay within the predefined
threshold currents so as to avoid a too close proximity to the nerve and
prevent nerve damage.

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The shorter the electrical pulse (= pulse width), the faster is the rise in current to the nerve.
This allows better discrimination by the physician as to whether the needle tip is sufficiently
close to the nerve. The stimulation needle should always be connected to the negative pole.
If the needle is connected to the positive pole, higher currents are required.
The conductive tip of the stimulation needle affects the geometry of the electrical field. The
smaller the emission site of the electrons at the tip of the needle, the higher is the current
density at this point and the lower the threshold level once the nerve has been localized
exactly.
Special attention must be paid as the current density at needle tip can exceed 2 mA/cm2
depending on stimulation settings.
The Stimuplex®HNS 12 is meant for long-term usage.
1.2. Intended Use
The nerve stimulator is intended for localisation of nerves in peripheral regional anesthesia.
Under no circumstances may it be used on a patient undergoing surgery.
1.3. Indications
•Surgical interventions on the upper and lower extremity
•Patients with high aspiration risk
•Hemodynamically unstable patients
•Postoperative analgesia to allow early mobilization and physical therapy
•Replantation surgery
•Diagnostic and therapeutic blockades
1.4. Contraindications
•Refusal of regional anesthesia by the patient
•Infection at the puncture site
•Preoperatively known neurological dysfunctions
•Anatomical abnormalities
•Severe coagulation disorders
•Insufficient liver function

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1.5. Warnings
Warnings and Precautionary Measures
General Precautionary Measures
1. The connecting socket of the stimulation needle may only be connected to the counter
plug of the connecting cable. The connecting cable plug may only be connected to the
nerve stimulator and the clip may only be connected to the skin electrode on the skin
of the patient. Under no circumstances should you allow these plugs/connections to
come in contact with voltage channeling components (e.g. electrical outlets) or metallic
objects.
2. To prevent anesthesia gases from exploding or flammable liquids from igniting, Stimu-
plex®HNS 12 may not be used in hazardous areas. To avoid injury to the patient, all
ported equipment in the vicinity of the patient must comply with the applicable rules
and regulations. All equipment and accessories must show compliance with EN 60601-1,
EN 60601-1-1 as well as the applicable collateral standards. The user should be aware
that, even when all rules are complied with for each piece of equipment, under worst
circumstances, all leakage currents or auxiliary patient-coupled currents can add up and
produce unacceptably high levels that can endanger the patient. The user must there-
fore check in advance whether the interconnected equipment might exceed allowable
limits under certain circumstances. Devices and equipment (system building) assembled
improperly can cause life-threatening injury to the patient.
3. The patients themselves should not come into contact with metallic objects that are
grounded or produce an electrical conductive connection with other equipment and/
or enable capacitive coupling. On these grounds, we recommend that an adequately
insulated, antistatic pad be placed on the operating table.
4. Unauthorized persons opening or attempting to repair Stimuplex®HNS 12 can create a
dangerous situation and will cause all warranty claims to be null and void.
No modification of the Stimuplex®HNS 12 is permitted.

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Warnings and Precautionary Measures for Stimuplex® HNS 12
Under no circumstance should the device be operated with accessories other
than those released and supplied by the manufacturer or listed in Section
5.10, “Instruments and accessories”. These accessories are EMC tested and
approved. Any other accessories can lead to serious impairment of the device
and system properties and cause permanent injury to the patient, user or
device.
5. Whenever high frequency surgical equipment is used simultaneously, there is an acute
danger of severe burns occurring at the Stimuplex®HNS 12 connection ports, the con-
necting cable, the tip of the needle and at the skin electrode. It is therefore imperative
to disconnect all connections to Stimuplex®HNS 12 before using high frequency surgical
equipment and to also remove the stimulation needle from the tissue. The stimulation
needle with its connecting cable acts like an antenna for high-frequency energy; this can
generate very high current densities at the needle tip and cause irreversible destruction
to the nerve fibers in this proximity. At the same time, the ported stimulator can rectify
the high frequency energy, which leads to extremely high direct currents and voltage
potentials at the electrodes. The direct current stimulation generated as a result can be
very painful and strong, and trigger irreversible electrophysiological reactions.
6. To prevent poor contact of the skin electrode (red clip) from leading to a malposition-
ing of the stimulation needle, the user must make sure that the skin electrode, which
functions like a neutral electrode here, shows sufficiently safe contact with low tissue
impedance. Fatty tissue, hair, dirt, repeatedly used skin electrodes and electrodes of
poorer quality can negatively impact tissue impedance, thereby incurring the risk of
neural damage. It is therefore recommended to select the contact surface carefully in
well-vasculated muscular areas only. Clean, shave and degrease the skin. At the same
time, do not position the skin electrode too far away from the puncture site. However,
thoracic application of the skin electrode is to be avoided.
7. The skin electrodes must not be applied to areas of injury.

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8. Only use high-grade, commercially available, CE-marked ECG single-use skin electrodes
with silver/silver chloride sensors precoated with gel. For non EU countries, CE marking is
not required on ECG skin electrodes. To achieve optimum nerve stimulation always make
sure the electrodes are undamaged and not dried out.
9. The nerve stimulator should not be used on patients with implanted electrical devices
(e.g. cardiac pacemakers) without prior consultation with an appropriate medical spe-
cialist. The stimulation current may cause interference with the implanted devices and
thereby put the patient at risk.
10. The perithoracic application of electrodes (around the ribcage, heart) can increase the
risk of cardiac fibrillation.
11. Stimulation should not be applied across or through the head, directly on the eyes,
covering the mouth, on the front of the neck, (especially the carotid sinus), or from
electrodes placed on the chest and the upper back or crossing over the heart.
12. The stimulation current should not drop below a specific value. By activating the option
“Current threshold” (see Section 3.6.), the Stimuplex®HNS 12 alerts you with an optical
and acoustic warning whenever the target stimulation current is set below this value.
13. If the stimulator shows a direct current or an offset direct current at the outlet, the
stimulatorshouldnotbeusedandmustbereturnedtothemanufacturerforrepair.These
failures can be detected by performing a simple functional test with the testing resistor
(see Section 5.1. Testing the Stimuplex®HNS 12).
14. The special precautionary measures specified by the EMC standard apply to electrical
medical devices. Portable and mobile RF communication devices can affect Stimuplex®
HNS 12 which can lead to functional failure of the device and/or system.
15. Dynamic electrical and dynamic magnetic interference fields can cause interactions
between device and system to occur which can impact the actual stimulation current
measurement and, in extreme cases, lead to error messages and possibly to the activa-
tion of a safety shut-off on the device. Do not use Stimuplex®HNS 12 in the proxim-
ity of equipment that produces strong electromagnetic fields such as cordless phones,
high frequency surgical equipment, shortwave or microwave medical equipment. The
stimulation needle may pick-up high frequency currents, which could cause damage to
nerves. (See Table 4 Recommended separation distances between portable and mobile RF
telecommunication devices and Stimuplex®HNS 12.)

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16. Do not connect Stimuplex®HNS 12 to other devices (except for instruments and acces-
sories, see section 5.10). If Stimuplex®HNS 12 is operated near another device, the user
mustmonitortheequipmentorsystemandcheckthattheconfigurationusedinthisway
is operated properly and as intended.
17. Other devices can interfere with Stimuplex®HNS 12 or the system, even if they show
compliance with the applicable CISPR emission requirements. Interference impulses can
be picked up by the stimulation current detector and thereby trigger an error display and,
possibly, a safety shutoff.
18. Operation of other devices or systems with Stimuplex®HNS 12 accessories can increase
emissions or reduce immunity to interference on devices or systems. Observe the sup-
plied EMC instructions concerning installation, initial setup and operation of the device
or system (see Section 9. Electromagnetic compatibility (EMC)).
19. Do not use the device after ingress of liquids. Ingress of liquids or humidity can cause an
electronic failure.
20. To avoid damage to the connecting cable and the device, do not hold or carry the device
by its connecting cables and/or its accessories. Do not wrap the cable around the device
or around other equipment.
21. Wrapping the connecting cable during normal operation of the stimulator generates
inductive components and, at very short stimulation pulses, can lead to a reduction in
stimulation efficacy and/or false measurements of the actual stimulation current. False
interpretations of the indicated values can be the result.
22. For safety reasons, never operate Stimuplex®HNS 12 if the battery is leaking, but return
it to the manufacturer for proper cleaning. The same applies if any liquid soaks through!
23. Donotcontinuetooperatethedeviceifrepeatederrormessagesappear.Thedevicemust
be returned to the manufacturer for proper repair.
24. Known undesirable side effects: Hematoma at puncture site

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25. Avoid contamination at the connections. Water and dirt impair the contact properties of
the plug connections and lead to undesired short circuits or leakage currents. This can
leadinpartorevenfullytochannelingofthestimulationcurrents,whichimpairsoreven
cancels out the stimulation effect completely. In this event, the device can no longer
properly indicate the actual current flowing to the patient.
26. To prevent damage to the device and its accessories, never use aggressive cleaning
agents. For further details, see Section 5.5. “Cleaning and disinfecting the Stimuplex®
HNS 12”. All accessories have to be visually inspected at regular intervals. The insulation
for cable and plug connections must not exhibit any damage.
27. The user must follow the instructions for use when operating Stimuplex®HNS 12 and
its corresponding accessories. Avoid any inadvertent contact of the stimulation needle
with bone, since this could irreversibly damage the needle and consequently traumatize
the tissue.
28. Keep accessories and device away from voltage-conducting objects. The electrostatic
and electromagnetic fields they radiate can impact the stimulation outcome and, under
certain circumstances, may lead to adverse stimulation effects in the tissue.
29. Before and during use, the device, the connecting cable and their plugs must be kept
completely clean and dry. Moisture and contamination will impair the function of the
nerve stimulator and/or the stimulation outcome.
30. Beawareofthepositionofmetallicimplantsinthetissue(e.g.platesorelectrodecables),
which may potentially channel stimulation signals to other sites where it can cause
damaging effects. Implanted electronic equipment can be impaired by the stimulation
current, which, in turn, will lead to malfunctions of the implants or even destroy them.
31. To avoid malfunctions of Stimuplex®HNS 12, check all functions prior to the intervention
and make sure that the accessories are in functional order. The accessories must meet
safety class type BF. Inspect all parts for any visible damage or manipulations. Never use
any damaged or manipulated parts!
32. To protect the patient from electrophysiological shocks through electrostatic discharges
(ESD), it is necessary for them to wear the appropriate clothing and to move around in
an appropriately secured environment. An electrostatic discharge (ESD) at the tip of
the needle can cause extremely high current densities to occur which can damage the
surrounding tissue.

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Conformity with the following standards:
DIN EN 50581 Technical documentation for the assessment of electrical and electronic products with respect to the
restriction of hazardous substances
DIN EN 1041 Information supplied by the manufacturer with medical devices
93/42/EEC and MPG Council Directive 93/42/EEC of 14 June 1993 concerning medical devices - Annex I
(Essential Requirements); Annex II (without section (4))
Directive 2006/66/
EC and ElectroG
(German Battery
Law)
Directive 2006/66/EC of the European Parliament and of the Council of 6 September 2006 on batteries
and accumulators and waste batteries and accumulators
Directive 2011/65/
EU Directive 2011/65/EU of the European Parliament and of the Council of 8 June 2011 on the restriction
of the use of certain hazardous substances in electrical and electronic equipment (RoHS II)
Directive 2012/19/
EU Directive 2012/19/EU of the European Parliament and of the Council of 4 July 2012 on waste electrical and electronic equipment (WEEE)
FDA 21 CFR 21
Part 801 FDA - Code of Federal Regulations Title 21 Part 801 - Subpart A - Labeling
FDA 21 CFR 21
Part 820 FDA - Code of Federal Regulations Title 21 Part 820 - QS regulation - Subpart K - Labeling and
Packaging Control
FDA 21 CFR 21
Part 830 FDA - Code of Federal Regulations Title 21 Part 830 - Unique device identification
IEC 60601-1 Medical electrical equipment –Part 1: General requirements for basic safety and essential performance
IEC 60601-1-2 Medical electrical equipment - Part 1-2: General requirements for safety – Collateral standard:
Electromagnetic compatibility - Requirements and tests (applicable to Ed. 3 and 4)
IEC 60601-1-4 Medical electrical equipment - Part 1-4: General requirements for safety - Collateral standard:
Programmable Electrical Medical Systems

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IEC 60601-1-6 Medical electrical equipment – Part 1-6: General requirements for safety – Collateral standard:
Usability
IEC 60601-1-9 Medical electrical equipment – Part 1-9: General requirement for basic safety and essential
performance - Collateral standard: Requirements for the reduction of environmental impacts.
IEC 60601-2-10 Medical electrical equipment – Part 2-10: Particular requirements for the safety of nerve and muscle
stimulators
IEC 60812 Analysis Techniques for System Reliability – Procedure for Failure Mode and Effects Analysis (FMEA)
IEC 62304 Medical device software - Software life-cycle processes
IEC 62353 Medical electrical equipment - Recurrent test and test after repair of medical electrical equipment
IEC 62366 Medical devices - Application of usability engineering to medical devices
ISO 13485 Medical devices – Quality Management Systems – Requirements for regulatory purposes
ISO 14971 Medical devices – Application of risk management to medical devices
ISO 15223-1 Medical devices - Symbols to be used with medical device label, labelling and information to be
supplied - Part 1: General requirements
Regulation (EC)
1907/2006 Regulation (EC) No 1907/2006 of the European Parliament and of the Council of 18 December 2006 concerning the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)
UL 60601-1 Medical electrical equipment - Part 1: General requirements for safety

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1.6. Constant voltage or constant current
According to Ohm’s Law I ~ U it is possible to use both voltage as well as current to measure
the intensity (amplitude) of the electrical stimulation. One speaks of constant voltage or
constant current devices.
The electrical resistance (impedance) in the circuit of a stimulation, which comprises the
sum of skin, tissue, needle, electrode cable resistance, etc., fluctuates within a large range.
It can move between < 1 kΩand infinity. Factors such as skin moisture, conductivity of the
skin and tissue and the potential resistance of the skin electrode can hardly be influenced.
If voltage (V) is selected as a measure of the intensity of the stimulation pulse, currents can
flow during treatment that differ greatly depending on the impedance and in accordance
with Ohm’s Law.
Therefore, it is better to use a nerve stimulator that allows the user to select the desired
current (mA) exactly between the two electrodes - skin electrode (anode) and stimulation
needle (cathode).
Nevertheless, a stimulator with constant current settings must be equipped with a very high
outputimpedance-ideallyinfinity-toreducetheresistancespossibleintheexternalcircuit
to negligible levels and to display the actually flowing current accurately. In recent years,
constant current devices, which allow selection of the desired current (mA) for the stimula-
tion pulse, have become established.
On the Stimuplex®HNS 12, the external load resistance can be up to 12 kΩ. If this load re-
sistance is exceeded, the nominal current flowing to the patient (actual stimulation current)
may be less than the set target stimulation current. In this case, the target stimulation
current and the actual stimulation current are displayed separately, and optical and acoustic
warning messages are set off. Moreover, the applied impedance is calculated constantly and
indicated in the LCD display.

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2. Description of the Device
Stimuplex®HNS 12 is a precision instrument for localizing neuronal pathways in the human
body. It was specifically designed to stimulate nerve fibers in living organisms with special
nerve stimulation needles that conventionally show a very high contact impedance with the
aim of determining their spatial position relative to the tip of the needle. The stimulation
needles are constructed in such a way that a local anesthetic can be injected near the nerve
fiber, which reversibly interrupts stimulus conductance.
The Stimuplex®HNS 12 nerve stimulator should only be used by a physician with an ap-
propriate knowledge in peripheral nerve blocks. The physician is responsible for the correct
usage of the nerve stimulator.
The functions of Stimuplex®HNS 12, Stimuplex®and Contiplex®stimulation needles as well
as the connecting cable by B. Braun are designed to work in perfect harmony. Only in this
way can an optimum of precision and reliability be achieved.
For more in-depth knowledge about the use of this device, its risks and side effects we rec-
ommend studying in detail the relevant literature cited in the „References“ Section.
Stimuplex®HNS 12 is supplied with the following basic equipment:
– Stimuplex®HNS 12 nerve stimulator
– 9-volt block battery
– Cable for connecting B. Braun stimulation needles (cable length 1.25 m)
– 10 kΩtest resistance
– User manual (this document)
– CD-ROM with user manuals in different languages (PDF files)
– Brief instructions for use
– Technical Service Manual
– Storage case for keeping Stimuplex®HNS 12 and accessories
Thespecialknobandthe Stimuplex®Pencan be purchased separately as accessories andkept
safely in the storage case in the intended compartments.

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Overview of the Stimuplex HNS 12 Nerve Stimulator

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Manufacturer’s factory settings configured on delivery (preset in the menu).
Max. desired current - 5.00 mA
Stimulus duration/Frequency - SENSe (see Section 2.2.)
Impedance - kΩ(is calculated automatically)
Range (not displayed) - 1 turn (can only be changed in the menu)
2.1. Checks before Start-up
The Stimuplex®HNS 12 is a class lla medical device according to Council Directive 93/42/
EEC. The device should not be used until it has been subjected to an on-site function test
and the persons responsible for operating the device are instructed how to use the device
with the aid of the user manual.
Before putting the Stimuplex®HNS 12 into operation, carry out the following tests.
1. Carry out a visual inspection of the electrode cable. Damaged cables must not be used.
Connect the electrode cable for connection with the stimulation needle to the front
of the nerve stimulator (to the middle 4-polar plug). The plug connector configuration
prevents wrong polarity connection.
2. Check if the battery is installed.
3. Press the ”Stand-by” key to switch on the Stimuplex®HNS 12. While you are holding
down the ”Stand-by” key to switch on Stimuplex®HNS 12, important equipment param-
eters are indicated in the unit’s display. After releasing the key, the device automatically
runs a self-test. If the self-test detects a defective function, an error code will appear in
the LCD display that switches off automatically after 8 seconds.
4. A battery symbol appears in the right lower corner of the LCD display that allows a check
of the battery voltage. The symbol flashes when the battery voltage drops below 7 V. The
device automatically shuts off when the battery voltage reaches < 6 V.
If no display appears when the Stimuplex®HNS 12 is switched on, change the battery
immediately (refer to Section 5.4. „Battery“).
Whenever the battery symbol is flashing, a new 9 V alkaline block battery
must be installed immediately to avoid having to abort a stimulator treatment.