HNS 12 User Manual sw ver 1.003.x Rev D

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Manufacturer:

Distributor:

In the US and Canada distributed by:

STOCKERT GMBH Bötzinger Straße 72 79111 Freiburg Germany

B. Braun Melsungen AG Hospital Care Division 34209 Melsungen Germany

B. Braun Medical Inc. 824 Twelfth Avenue Bethlehem, PA 18018-3524

Telefon: +49-(0)761-20716-0 Telefon: +49-(0)5661-71-0 Phone: 1-800-854-6851 Telefax: +49-(0)761-20716-20 Telefax: +49-(0)5661-71-4845 Fax: 1-610-758-9020 Email: [email protected] Email: Email: [email protected] http://www.stockert.de [email protected] http://www.bbraunusa.com/stimuplex http://www.bbraun.com

Caution: 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.

Stimuplex® HNS 12 User manual Order number: 6043570 – Rev. D – valid for software version 1.003.x Meliseptol®, Stimuplex® and Contiplex® are registered trademarks of B. Braun Melsungen AG

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Contents

Contents

Page

1. 1.1 1.2 1.3 1.4 1.5

Preface ...5 Principles of peripheral electrical nerve stimulation (PNS)...6 Area of application ...6 Indications ...7 Contraindications ...7 Warnings ...7 Constant voltage or constant current...11

2. 2.1 2.2 2.2.1 2.2.2 2.2.3 2.2.4 2.2.5 2.2.6 2.2.7

Description of the device ...13 Checks before start-up...15 Technical description ...17 Plug Connections ...17 Current regulator (dial and keys) ...18 Single-handed remote control (Stimuplex® Remote Control)...19 Sound...20 LED...20 Display modes...21 Menu structure ...22

3. 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8

Operation of the Stimuplex® HNS 12 ...24 Switch on / Switch off (ON/OFF)...24 Selecting the current adjustment range ...25 Selecting the stimulation current ...25 Selecting the stimulus duration ...26 Selecting the stimulation frequency ...27 Current threshold display ...28 Checking the battery voltage ...28 Additional information – Menu info...28

4. 4.1 4.1.1 4.1.2 4.1.3 4.1.4 4.2 4.2.1 4.2.2 4.2.3

Setting parameters and options for future switch-on procedures...29 Setting switch-on values for stimulation parameters ...29 Current adjustment range ...29 Stimulus duration ...30 Frequency ...30 Current threshold display ...30 Setup ...31 Tone ...31 Dial turns ...31 Contrast on the LCD display ...32

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Contents

Page

14.2.4 Automatic switch off ...32 14.2.5 Date and time ...32 14.2.6 Language ...33 14.2.7 Options ...33 14.2.7.1 Factory standard...33 14.2.7.2 Displaying the electrical charge of the stimulation pulse (electrical charge nC) ...34 14.2.7.3 Current adjustment ...34 14.2.7.4 Additional stimulus duration...34 14.2.7.5 SENSe option...34 15. 15.1 15.2 15.3 15.4 15.5 15.6 15.7 15.8 15.9 15.10

Initial setup, maintenance and notes...35 Testing the Stimuplex® HNS 12 ...35 Special technical features ...35 Technical data ...36 Battery...36 Cleaning and disinfecting the Stimuplex® HNS 12...37 Maintenance and safety checks ...37 Equipment logbook...37 Notices, warranty...38 Error messages ...39 Instruments and accessories...41 Stimuplex® HNS 12 and Accessories, Spare parts, Stimuplex® and Contiplex® needles...41

16.

References ...44

17.

Appendix ...45

18.

Symbols on Stimuplex® HNS 12 ...52

19.

Electromagnetic compatibility (EMC)...53

10. 10.1 10.2 10.3 10.4

Specific requirements for the US market ...58 Addition to Page 37 of the Manual – “5.6 Maintenance and safety checks” ...58 Change from Page 38 of the Manual – “5.8 Notices, warranty” ...59 Change from Page 38 of the Manual - “5.8 Notices, warranty”...59 Change from pages 40 – 42 of the User manual -...61 "Stimuplex® HNS12 and Accessories, Spare parts, Stimuplex® and Contiplex® needles"

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Preface

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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. 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 electrical 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 nerve stimulator is intended only for the pre-operative localization of nerves; under no circumstances may it be used on a patient undergoing surgery. 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. 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 anesthetized 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 stimulation. The Aalpha motor fibers have the shortest chronaxia (50–100 μs). The afferent fibers that transmit pain sensation (Aδ and 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). When unipolar needles (insulated and with conductive tip) are used, the current necessary to trigger

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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. 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.

1.2 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

1.3 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

1.4 Warnings Warnings and precautionary measures General precautionary measures: 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

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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. To prevent anesthesia gases from exploding or flammable liquids from igniting, Stimuplex® 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 therefore 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. 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.

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. 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 connecting 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. To prevent poor contact of the skin electrode (red clip) from leading to a malpositioning 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 sur-

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face 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. The skin electrodes must not be applied to areas of injury. 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. The nerve stimulator should not be used on patients with implanted electrical devices (e.g. cardiac pacemakers) without prior consultation with an appropriate medical specialist. The stimulation current may cause interference with the implanted devices and thereby put the patient at risk. The perithoracic application of electrodes (around the ribcage, heart) can increase the risk of cardiac fibrillation. 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 stimulation current is out of tolerance. If the stimulator shows a direct current or an offset direct current at the outlet, the stimulator should not be used and must be returned to the manufacturer for repair. The special precautionary measures specified by the EMC standard apply to electrical medical devices. Portable and mobile HF communication devices can affect Stimuplex® HNS12 which can lead to functional failure of the device and/or system. 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 activation of a safety shut-off on the device. Do not use Stimuplex® HNS 12 in the proximity of equipment that produces strong electromagnetic fields such as cordless phones, HF high frequency surgical equipment, short-wave or microwave medical equipment. The stimulation needle may pick-up high frequency currents, which could cause damage to nerves. Do not connect Stimuplex® HNS 12 to other devices. If Stimuplex® HNS 12 is operated near another device, the user must monitor the equipment or system and check that the configuration used in this way is operated properly and as intended. Other devices can interfere with Stimuplex® HNS 12 or the system, even if they show compliance with the applicable CISPR emission requirements. Interference impulses greater than 3 V/m within the fre-

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quency range up to 100 MHz can be picked up by the stimulation current detector and thereby trigger an error display and, possibly, a safety shutoff. 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 supplied EMC instructions concerning installation, initial setup and operation of the device or system (see Section 9. Electromagnetic compatibility (EMC)). 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. 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. 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! Do not continue to operate the device if repeated error messages appear. The device must be returned to the manufacturer for proper repair. 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 lead in part or even fully to channeling of the stimulation currents, which impairs or even cancels out the stimulation effect completely. In this event, the device can no longer properly indicate the actual current flowing to the patient. 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. The user must follow the instructions for use when operating Stimuplex® HNS 12 and its corresponding accessories. When using sterile accessories, always comply with standard sterile precautionary measures. Avoid any inadvertent contact of the stimulation needle with bone, since this could irreversibly damage the needle and consequently traumatize the tissue.

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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. 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. Be aware of the position of metallic implants in the tissue (e.g. plates or electrode cables), 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. 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! 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. Conformity with the following standards: EN 60601-1; EN 60601-1-2; EN 60601-1-4; EN 60601-1-6; EN 60601-1-8; EN 60601-2-10; UL 60601; 60812 (FMEA); ISO 9001:2000; ISO 13485:2003; ISO 14971:2000; MPG/Council Directive 93-42-EEC.

1.5 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 kΩ and infinity. Factors such as skin moisture, conductivity of the skin and tissue and the potential resistance of the skin electrode can hardly be influenced.

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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 output impedance – ideally infinity – to reduce the resistances possible in the external circuit 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 stimulation pulse, have become established. On the Stimuplex® HNS 12, the external load resistance can be up to 12 kΩ. If this load resistance 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

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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 appropriate 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 a optimum of precision and reliability be achieved. For more in-depth knowledge about the use of this device, its risks and side effects we recommend 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 kΩ test resistance – User manual (this document) – CD-ROM with user manuals in different languages (PDF files) – Brief instructions for use – Storage case for keeping Stimuplex® HNS 12 and accessories The Stimuplex® Remote Control, the control knob for sterile handling, the Stimuplex® Pen and the Stimuplex® Switch can be purchased separately as accessories and kept safely in the storage case in the intended compartments.

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Overview of the Stimuplex® HNS 12 Nerve Stimulator

LCD display

LEDs

Stimuplex HNS 12 R

Dial for regulating the target stimulation current

MENU

Single-handed remote control (optional) for sterile operation

mA

Current adjustment range

ms

Stimulus duration

Hz

Stimulation frequency - On/off - Home

MENU

Stimuplex DIG RC

Connecting cable

Stimulation needle

Stimuplex HNS 12 R

mA ms Hz

MENU

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Manufacturer’s factory settings configured on delivery (preset in the menu). Max. desired current Stimulus duration/Frequency Impedance Range (not displayed)

- 5.00 mA - SENSe (see page 17) - kΩ (is calculated automatically) - 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. 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. Check if the battery is installed. Press the ”ON/OFF” key to switch on the Stimuplex® HNS 12. While you are holding down the ”ON/OFF” key to switch on Stimuplex® HNS 12, important equipment parameters 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. 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 the “Battery” section). Whenever the battery symbol is flashing, a new 9 V alkaline block battery should be installed immediately to avoid having to abort a stimulator treatment. Connect the red clip for the skin electrode and the insulated 2-mm male plug for the stimulation needle with the 10 kΩ test resistance (included in the equipment supplied).

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The LCD display shows the current operating conditions: Electrical charge (when option is activated) Maximum current adjustment range Stimulus duration Stimulation frequency Impedance When Remote Control is activated Symbol for battery voltage Desired target stimulation current After switching on Stimuplex® HNS 12, the target stimulation current is zero; in other words, no stimulation pulse is generated and the LED is not flashing. If the target stimulation current is > 0.00 mA and the actual stimulation current flowing does not deviate by more than 0.04 mA from the target stimulation current, the green LED lights up (or yellow, if the optionally adjustable current threshold has been undershot) and a stimulation frequency sound becomes audible. The actual current is indicated automatically and only indicated as a warning when it deviates from the target current. In this state, the LED will light up red and a higher-pitch warning signal will be sounded. Use the dial to set the maximum current of 5.00 mA. No error message should appear at a load resistance of 10 kΩ (see accessories). The LED flashes green at the selected stimulation frequency. The sound is dependent on the preselected stimulation current, when ”sound variable” has been configured in the sound-menu. Now release the connection between clip and male plug. The warning message ”actual current is less than target current” appears, both stimulation currents are displayed (see Section 2.2.6.2 Stimulation mode with warning), the LED flashes red because no current is flowing, and the click or beep sound starts ticking louder at a higher pitch. To switch off the nerve stimulator, hold down the ”ON/OFF” key until the display disappears (switchoff time = 1 second). If the key is released during this switch-off phase, the device switches back to „ON“ status. Refer specifically to the Section ”Warning and Safety information” before using the Stimuplex ® HNS 12 on a patient. If the device does not behave as previously described, it must not be put into operation. Please contact the manufacturer or distributor listed. Maintenance on medical equipment may only be performed by the manufacturer or persons explicitly authorized by the manufacturer. Stimuplex® HNS 12 is designed for regional anesthesia to optimally localize peripheral nerves.

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2.2 Technical description Stimuplex® HNS 12 generates square pulses with selectable stimulus duration and continuously adjustable stimulation current. The range of adjustment of the pulse current from 0.00 to 5.00 mA peak-to-peak can be reduced to 0.00 to 1.00 mA with the ”mA” button. This 1 mA range allows extremely precise adjustments of the stimulation current. The stimulation frequency and stimulus duration can be varied for different applications. The Stimuplex® HNS 12 nerve stimulator features the option of selecting a frequency of either 1 Hz, 2 Hz or 3 Hz for SENSe and a stimulus duration of 0.05 ms – 0.10 ms – 0.30 ms – 0.50 ms – 1.00 ms. The Stimuplex® HNS 12 measures the tissue impedance and displays it in kΩ. This measurement allows for a quick check and visualization of the current state of the circuits. Sequential electrical nerve stimulation (SENSe) technique utilizes an alternating sequenced stream or series of three electrical pulses of varying pulse duration at any given amperage. The two accurate 0.1 ms pulses are sequenced with a pulse of longer duration (e.g. 0.3 ms). A longer duration pulse elicits motor responses at greater distance at lower frequency, increasing sensitivity. The shorter pulses maintain the accuracy underlying successful nerve location, whereas the longer duration pulse enables stimulation at a greater distance. Therefore, SENSe maintains specificity and accuracy, while increasing sensitivity. Clinically, this translates into more motor response information at distance from the nerve. Moving the needle toward the nerve increases the strength or frequency of the motor response. In the clinical setting, SENSe gives more continuous feedback and markedly diminishes the disappearance of motor responses once they are encountered. Therefore SENSe automatically increases visual clues and feedback during nerve location by needle movement alone with less necessity to adjust the amperage control of the nerve stimulator. SENSe mode can be activated in the “Options” menu. SENSe is valid for software version 1.003.x or newer only.

2.2.1 Plug Connections Two polarized plug connections are located on the front of the nerve stimulator: - 3-polar plug for connecting single-handed remote control (Stimuplex® Remote Control can be operated under sterile conditions) - 4-polar plug for connecting the electrode cable to the stimulation needle and skin electrode or the Stimuplex® Switch.

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2.2.2 Current regulator (dial and keys) Current regulator (dial): The current regulator (dial) is used to adjust the target stimulation current. The dial can be turned infinitely, but is graduated. The maximum currents (5 or 1 mA) can be achieved either with 2 turns, or 1 Dial (factory setting). The settings 1 or 2 dial turns are configured in the ”Setup” menu, ”Dial turns”. For maximum accuracy, select the two turn configuration and use the intermediate steps between the stops.

Stimuplex HNS 12 R

mA ms Hz

MENU

1 Dial turn 5.00 mA range - Resolution = 0.02 mA from 0.00 mA to 0.49 mA - Resolution = 0.10 mA from 0.50 mA to 1.90 mA - Resolution = 0.25 mA from 2.00 mA to 5.00 mA 1.00 mA range - Resolution = 0.02 mA from 0.00 mA to 5.00 mA 2 Dial turns 5.00 mA range - Resolution = 0.01 mA from 0.00 mA to 0.55 mA - Resolution = 0.10 mA from 0.60 mA to 5.00 mA 1.00 mA range - Resolution = 0.01 mA from 0.00 mA to 1.00 mA

Keys: • ”mA” key: Sets the desired stimulation current range. • ”ms” key: Sets the desired stimulus duration. • ”Hz” key: Sets the desired stimulation frequency. • ”ON/OFF” key: On and off switch for the Stimuplex® HNS 12. Briefly press the ”ON/OFF” key: To jump from the menu mode to the normal stimulation mode or to immediately delete a potentially existing marking in the stimulation mode (e.g. 5.00 mA). • MENU arrow keys: For navigation and settings in the menu.

The Stimuplex® HNS 12 is very user friendly in its handling. It features a menu structure with ”Main Menu” and ”Setup” with which the user can configure user settings, such as switch-on settings, volume and tone pitch, dial resolution, display contrast, automatic switch-off time, date, time and language as well as further options. Navigation through these menus is done with the arrow keys.

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Right arrow: Is used to activate the Main Menu or submenus and select or confirm an option. Up and down arrows (Up and down keys): Are used to select a menu item or option and/or changes values. Fast selection or change by holding down the up/down key. Left arrow: Is used to jump back one menu level

2.2.3 Single-handed remote control (Stimuplex® Remote Control) As an alternative to the dial, the target stimulation current can also be set using the single-handed remote control, available as an optional accessory. With this feature, Stimuplex® HNS 12 can be easily operated under standard sterile conditions without an additional person.

Stimuplex DIG RC

The device recognizes the single-handed remote control automatically as soon as it is used. A symbol for the single-handed remote control appears in the LCD display above the battery symbol (active when dots appear, inactive when no dots and the downward arrow are displayed). For safety reasons, the single-handed remote control is not activated by the device until the target stimulation current has been set to zero with both the dial as well as with the single-handed remote control. Afterwards it is possible to set the target stimulation current with the remote control. If required, please press the unlabelled key on the single-handed remote control (= lowers the value) until the symbol without dots disappears. The single-handed remote control is released when the target stimulation current is set to 0.00 mA and the remote control symbol is invisible. When single-handed remote control is activated (symbol with 2 dots), the dial has no function. For safety reasons, neither the current range nor the stimulus duration can be increased when the single-handed remote control is activated, without having previously set the target current to zero. The automatic current adjustment (option) is also turned off. When the single-handed remote control is in use, the smallest adjustable stimulation current is approx. 0.09 mA due to technical reasons. Attention! The target stimulation current can be modified during menu navigation, if the remote control is activated. For safety reasons, if the single-handed remote control is disconnected from the Stimuplex® HNS 12, the device automatically resets the stimulation current back to zero and the dial is reactivated for setting the stimulation current.

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2.2.4 Sound Each stimulation pulse (preset stimulation current is flowing) generates a clear click or beep sound. The volume increases from a low pitch during maximum stimulus current to a high-pitch tone to audibly signal that the current threshold is being approached. However, changes in sound pitch can also be turned off in the ”Setup” menu, ”Tone”, ”Variable tone” so that the same sound is always heard regardless of the respective stimulation current. The type of sound can be selected in the ”Setup” menu, ”Tone”, ”Mode”. The user can choose between a click and a beep sound. When warnings (actual stimulation current < target stimulation current, target stimulation current < current threshold, automatic switch off, EEPROM) and errors are signaled, the click or beep changes to a louder and higher alarm pitch. Whenever any key is operated, a short, clear beep is audible. The volume can be adjusted in the ”Setup” menu, ”Tone”, ”Volume” at settings ranging from 0 (a very quiet ticking sound in the stimulus frequency; warning signals remain) to 8 (max. volume).

2.2.5 LED • Green LED: Actual stimulation current = target stimulation current • Yellow LED: Actual stimulation current = target stimulation current, below the threshold current (if current threshold activated is, see Section 3.6) • Red LED: deviation actual stimulation current < target stimulation current (starting from a deviation of – 0.04 mA), errors.