STIMPOD NMS410-450X Quantitative NMT Monitor Precision Nerve Locator Ver12 User Manual

Manufacturer Xavant Technology PTY (LTD) Unit 102, The Tannery Industrial Park, 309 Derdepoort Rd Silverton, Pretoria, South Africa, 0184 Tel: +27 (0) 12 743 5959 Fax: +27 (0) 86 547 0026 E-mail: [email protected] Web: www.xavant.com

Legal Representative in the EU

Contraindications: • • •

Warnings: • • • •

Emergo Europe Prinsessegracht 20, 2514 AP The Hague The Netherlands

•

EU Importer

•

MedEnvoy Prinses Magrietplantsoen 33 – Suite 123 2595 The Hague, The Netherlands

•

Caution

•

Federal (US) law restricts this device to sale by or on the order of a physician.

Indications for use: This product is a nerve stimulation device designed to be used by an anaesthetist during • General Anaesthesia, for the purpose of establishing the efficacy of a Neuromuscular Blocking Agent using non-invasive surface electrodes (NMS450X). • Regional Anaesthesia for the purpose of • Nerve mapping using the non-invasive Nerve Mapping Probe (supplied). • Nerve locating using invasive electrodes/needles (not supplied).

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Infection of the puncture site. Known neurological disorders. Severe coagulation disorders.

• • • • • •

Read the entire User Manual before attempting to use the device. Use of cables or accessories other than those supplied with the STIMPOD may result in serious injury. Maintenance on this device may only be performed by the manufacturer or persons explicitly authorized by the manufacturer. Do not use the STIMPOD in close proximity to equipment that produces strong electromagnetic fields, such as high frequency surgical equipment. The cable leads could act as antennae and dangerous currents could be induced as a result. Do not apply the STIMPOD to patients with implanted electrical devices, such as cardiac pacemakers, without first consulting with an appropriate medical specialist. The device should not be used adjacent to or stacked with other equipment and that if adjacent or stacked use is necessary, the device should be observed to verify normal operation in the configuration in which it will be used. The patient should avoid contact with metallic objects that are grounded, produce an electrical conductive connection with other equipment and/or enable capacitive coupling. The cables should be positioned in such a way that they do not contact either the patient or other cables. Simultaneous connection of a patient to high frequency surgical ME equipment and the STIMPOD may result in burns and possible damage to the stimulator. Operation in close proximity (e.g. 1m) to a shortwave or microwave therapy ME equipment may produce instability in the stimulator output. Application of electrodes near the thorax may increase the risk of cardiac fibrillation. No modification of this equipment is allowed. Do not modify this equipment without authorization of the manufacturer. If this equipment is modified, appropriate inspection and testing must be conducted to ensure continued safe use of the equipment.

Cautions: • • • • • •

• • • • • •

•

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Prior to changing the batteries be sure to switch off the device and remove all the cables. Remove elements which may adversely affect the connection between the electrodes and the skin, e.g., dirt, hair, oil. Prior to placing any applied part (such as Accelerometer, ECG and EMG Electrodes), inspect the skin area for any pre-existing conditions and avoid if possible. Ensure that electrodes are not damaged or dried out. Large current densities associated with failing electrodes may cause superficial burns. For acceleromyography, the Stimpod is designed to be compatible with standard ECG electrodes, however, for high currents the use of a dedicated NMT electrode such as the Xavant XT45008 is recommended. Electrodes that have current densities exceeding 2mA/cm2 may require special attention of the operator. This product must be stored at 0 – 50°C. This product must be transported in the carry case provided. This product and all the accessories have been certified latex free. Inspect all parts for any damage or manipulation. Never use any damaged or manipulated part! If an electrically conductive surface of the Stimpod device or its cables are exposed, such electrically conductive surface may shock a person handling it. Do not use such a device or accessory, please contact the manufacturer for repair. The refractory period delay is set at a default value to prevent the user from repeating stimulation while the nerve synapse is recovering from effects of the previous stimulation. A refractory period of less than 12 seconds in TOF mode is not advisable as measurements might not represent the effect of blocking agents on the neuromuscular junction. Do not place the STIMPOD stimulation electrodes in close proximity to other sensing electrodes i.e. EEG or ECG electrodes.

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operating room is described in the guidance and manufacturers declaration. The device can be used on any part of the body except for limitation described in warnings and cautions or identified in section 3 for the NMT mode.

Warranty: • •

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The Stimpod (device only) carries a 24 month warranty against manufacturing defects, provided that the device was used in accordance with the operating instructions. The cables included in the Stimpod kit carry a 6 month warranty against manufacturing defects, provided that the cables were used in accordance with the operating instructions. The Stimpod enclosure should not be opened under any circumstances. Opening the unit will void the warranty.

STIMPOD (NMS 410/450X) conforms to the following standards: • • •

IEC 60601-1, IEC 60601-2-10, IEC 60601-2-40 IEC 60601-1-2: CISPR 11 Group1 class A; IEC 61000-4-2; IEC 61000-4-3 ISO 13485, Directive 93-42-EEC

Application Specification: • • •

The patient population includes patients of all ages, weight and nationality. Patient health and state is described in contraindications, warnings and cautions. The user must be a medical professional with knowledge of anatomy. The use environment requirements of the device such as the medical practice and

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Contents 1.

Getting to know the STIMPOD (NMS 410/450X)

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1.1) 1.2) 1.3) 1.4) 1.5) 1.6) 1.7) 1.8)

Device Description Device Layout Screen Layout Accessories Warning Screens Open Circuit Detection Auto Shutdown Symbols

5 6 7 8 10 12 12 12

2.

Nerve Locating/Mapping Mode (NMS 410/450X)

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2.1a) 2.1b) 2.2) 2.3) 2.4)

Adjusting the Current in LOC mode Adjusting the Current in MAP mode Adjusting the Pulse Width Proximity Indicator Adjusting the Twitch Frequency

14 15 16 16 16

3.

Neuromuscular Transmission (NMT) Monitoring Mode (NMS 450X)

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3.1) 3.2) 3.3) 3.4) 3.5)

Introduction to NMT Monitoring Cables and Sensors for NMT Monitoring Stimulation Sites for NMT Monitoring AMG Patient Setup EMG Patient Setup

17 17 18 19 20

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3.6) 3.7) 3.8) 3.9) 3.10) 3.11) 3.12) 3.13) 3.14) 3.15)

Adjusting the Current Adjusting Stimulation Mode Adjusting the Twitch/ Tetanus Frequency Train of Four Mode (TOF) Double Burst Mode (DB) Post Tetanic Count Mode (PTC) Supra Maximal Current Mode (SMC) Auto Mode Twitch Mode Tetanus Mode

22 22 22 23 23 24 24 25 26 26

4.

Setting up Device Defaults

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4.1) 4.2) 4.3) 4.4)

Setup Menu User Settings NMT Settings Locate Settings

28 28 29 30

5.

Technical Notes

32

5.1) 5.2) 5.3) 5.4)

Performance Testing Specifications Cleaning and Disinfecting STIMPOD Guidance and Manufacturers Declaration

32 36 36 37

Products & Accessories

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Getting to Know the STIMPOD (NMS410/450X)

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1.1) Device Description The STIMPOD NMS450X is a quantitative Neuromuscular Transmission (NMT) monitor utilizing either tri-axial accelerometry or electromyography to provide real-time quantitative feedback. The Stimpod NMS 410 as well as Stimpod NMS 450X is also a precision nerve locating tool used for localizing specific neural pathways. Localization of nerves by electrical stimulation involves connecting the nerve stimulator to a conducting needle through which local anaesthetics can be injected. The distance of the needle (cathode) from the nerve can be estimated by establishing the minimum threshold current required, to facilitate a neuromuscular response. CAUTION: This device should only be used by a qualified physician with appropriate knowledge in anaesthesia. The sale or purchase of the device is restricted to licensed medical practitioners, as governed by the law of the country/state in which he/she practices, or where the device is to be used.

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1.2) Device Layout

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3

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Enter / Frequency Button Press to toggle between Frequencies. Press to Enter in setup menu. Menu / Pulse Width Button NMS 410/450X (LOC/MAP Mode) Press to toggle between Pulse Widths. Press and hold to access Setup Menu. NMS 450X (NMT Mode) Press to toggle between Stimulation Modes. Stimulating LED indicator Flashing Green: Stimulus delivered. Flashing Red: Open Circuit.

Display

The Wheel Adjust current in the main operating mode. Navigate the Setup Menus.

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On / Off Button Press to switch unit on / off.

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30mA Auto

NM T

30.21mA 00:15 T O F

Minimal

2 u

3 4

Pause Button 5 NMS 410/450X (LOC/MAP Mode) Press to Stop / Start Stimulation. 6 NMS 450X (NMT Mode) Press and release to elicit a single stimulation. Press and hold to activate a repeated stimulation. 7

6

Multi Functional Clip

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Cable Connector Insert the combined Nerve Mapping / Locating Cable or the NMT cable to activate the relevant 1 mode.

men

1

NMS 450X

Battery Compartment Cover

1.3) Screen Layout Linear mode Non-Linear mode

6 Current Mode Nerve locating mode Nerve mapping mode NMT mode (NMS450X)

1

Data Cable 2

7 Speaker Volume 8 Battery Status

Current Setting 3 Adjust using wheel

9 Average current of actual stimulus 10 Warning: Notifies the user of a discrepancy

between current setting and average current of actual stimulus. 11 Diagnostic or Warning screens 12 Stimulating Frequency Setting Adjust using Enter / Hz width button

Facial Mode 4 Pulse Width Setting 5 Adjust using Menu / Pulse width button

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Diagnostic Screen NMS 410/450X (LOC / MAP Mode) • Indication of current setting

NMT Mode (NMS450X) Stimulation mode TOF, DB, PTC, TET, TWI, SMC and Auto

Diagnostic Screen NMS 450X (NMT Mode) • Real-time quantitative feedback

• Proximity indicator arrow

• Countdown timer for repeat mode

• Calculated Charge Setting • Average charge of actual stimulus • 0 mA

NMS 450X

• Calculated percentage TOF/DB ratio OR TOF/PTC Counts

• Graph indicating shape of actual current stimulus

A

E

G

G

• Cable Type Identifier: M or M

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1.4) Accessories WARNING: Use of cables or other accessories other than those supplied with the STIMPOD may result in serious injury. NOTE: ECG Electrodes and Nerve Locating needles are not included in this package. CAUTION: A sterile wipe should be applied to the Nerve Mapping Probe prior to use.

Nerve Mapping/ Nerve Locating Cable (XT-41014): • This cable is used to activate the Nerve Mapping/Locating mode on the STIMPOD. • The red (anode) connector is designed to clip on to a standard ECG electrode. • The ergonomically designed cutaneous Nerve Mapping Probe presents the user with a simple and reliable Nerve Mapping solution. • The 2mm needle connector will accommodate various makes of needles.

AMG Accessories (STIMPOD NMS450X) NMT Monitoring Cable AMG (XT-45025) and 3.5m (XT-45025A): • This cable is used to activate the NMT mode on the STIMPOD. • The red (anode) and black (cathode) connectors are designed to clip onto the Xavant NMT electrode (XT-45008) or onto a standard ECG electrode. • The accelerometer is designed to attach to the contracted appendage (in the case of the ulnar nerve, this will be the thumb).

NMT Electrode (XT-45008): • The colour coded connections indicate the polarity for the NMT cable connections • The larger surface area of the red (anode) electrode reduces the current density of the anode and prevents hyperpolarization • The proprietary gel and gel interface was specifically designed for transmission of large currents.

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EMG Accessories (STIMPOD NMS450X) NMT Monitoring Cable EMG 1.8m (XT-45003) and 3.5m (XT-45003A): • The EMG cable is used to enable EMG based NMT Monitoring on the Stimpod. • The EMG cable connects directly to the EMG Electrode.

EMG Electrode Large (XT-45009L) and Small (XT-45009S): • The disposable EMG Electrode is applied directly to the patient for EMG based NMT Monitoring using the EMG cable.

Smart Data Cables (STIMPOD NMS450X) Smart Data Cable Philips RS232 (XT-45100C-PHI): • Interface AMG/EMG data directly to a compatible Philips monitor.

Smart Data Cable NMShow (XT-45100A-NMS): • Interface AMG/EMG data directly to a PC using the NMShow software.

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1.5) Warning Screens

Insert Cable

Insert Cable: This is the first prompt which the user will encounter as the unit is switched on, and signals that the unit is waiting for the cable to be inserted.

Cable Not Recognised

Cable not recognised: This warning informs the user that the inserted cable is not compatible with the NMS 410/450X.

Pause

Pause: This warning informs the user that the PAUSE button was pressed. The STIMPOD will pause all its activities and wait for the PAUSE button to be pressed again.

Replace Batteries

Replace Batteries: This warning informs the user that the batteries are depleted beyond an acceptable level. Continuing to operate the device thus will make it unreliable. To prevent this the STIMPOD flashes this warning for 4 seconds before switching off.

Open Circuit Detected

Open Circuit Detected: This warning informs the user that the contact points of the connected accessory are not forming a closed circuit. This warning will be accompanied by a red flashing LED, every time the unit attempts to stimulate.

Refractory Delay Active

Refractory Delay Active: Once a TOF, DB, or PTC stimulation is performed, the refractory period timer is initiated. During the countdown time it will not be possible to perform another stimulation. If another stimulation is attempted, this warning screen will appear.

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Press Enter To Confirm

Current Adjustment in NMT Mode: When attempting to adjust the current while in NMT mode the device will show this message, requesting the user to confirm the adjustment of the current.

Stimulation In Progress

Stimulation in Progress: Warning shown when the play button is pressed during stimulation.

EMI Warning

EMI Warning: Warning shown when a high level of electromagnetic interference is detected.

Component Error: The STIMPOD has detected a component failure. Please send the device back to the manufacturer for repair!

Incorrect Electrode Placement

Incorrect/Check electrode placement: Warning shown when SMC is unable to find a supramaximal current value.

No NMT Data received

No NMT Data received: Warning shown when either the AMG or EMG sensor did not respond.

Stimulation aborted

Stimulation aborted: This warning is shown when: • SMC: Measured current is more than 10% less or more than the set current. • NMT: The stimulation was interrupted.

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1.6) Open Circuit Detection

1.8) Symbols

The Stimpod performs impedance measurements at regular intervals to detect whether the connection between the STIMPOD and the patient comprises a closed circuit. Closed Circuit Detected: • Stimulation will take place. • Stimulating sound will be heard (Single or multiple beeps depending on proximity indicator setting. Sound pitch will follow the current intensity). • The LED stimulus indicator will pulse green with every successful stimulus attempt. • The diagnostic screen will provide active feedback on every pulse delivered.

Manufacturer

Manufacturing Date (Year)

Caution

Separate collection for electrical and electronic equipment (Applicable to EU community only)

Serial Number

Representative in the EU

Catalogue Number

Prescription use only

Open Circuit Detected

Open Circuit Detected: • No stimulation will take place. • No stimulating sound will be heard. • The LED stimulus indicator will pulse red with every unsuccessful stimulus attempt. • A warning screen will appear in the diagnostics screen indicating that an open circuit was detected.

1.7) Auto Shutdown STIMPOD will shut down after 10 minutes of no user or patient interaction.

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90% 90% 10% 10% Type BF Applied Part

Non-sterile

Humidity limitation

Consult instructions for use

Medical Device

EU Importer

50°C 50°C 0°C0°C Temperature limit

Nerve Locating/Mapping Mode (NMS 410/450X) Locating mode (LOC) Localisation of nerves by electrical stimulation involves connecting the nerve stimulator to a conducting, locating needle (not supplied) through which local anaesthetics can be administered. This procedures involves subcutaneous stimulation of the motor component of the relevant peripheral nerve, to ‘locate’ the nerve. • •

Select this mode by inserting the Nerve Locating / Mapping cable. The STIMPOD will automatically default to the Nerve Locating current range (0.00 5.00 mA) and display the ‘ LOC ’ indicator.

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This mode offers the user the means to do nerve mapping and locating without having to switch or unplug cables. When inserting the Nerve Mapping / Locating Cable, the STIMPOD will default to the Nerve Mapping current range (0-5mA). Current will be directed to the Nerve Mapping probe and the STIMPOD will attempt to stimulate. The moment that the needle penetrates the skin the cable will sense it and inform the STIMPOD. The stimpod will switch to Nerve locating mode. If contact between the needle and patient is broken, and the nerve mapping probe touches the patient, STIMPOD will switch back to the nerve mapping mode and start monitoring the needle - patient connection again. Whenever the nerve mapping probe and the nerve locating needle simultaneously make contact with the patient the needle will have first priority.

Mapping Mode (MAP) •

This mode is selected when the Nerve Mapping / Locating cable is inserted.

Percutaneous nerve mapping enables the anaesthesiologist to map out a particular superficial nerve prior to nerve location with the needle. This is accomplished by stimulating the motor component of the relevant peripheral nerve percutaneously with the nerve mapping probe. This technique ensures a higher success rate for directing the needle to the correct nerve.

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When using the Nerve Locating / Mapping Cable 3 Warning: Notifies the user of a discrepancy between current setting and average current of actual stimulus. 4 If sound is enabled: STIMPOD will beep every time that a stimulus was delivered. The pitch of the sound will follow the current intensity level. 5 Average current of actual stimulus

Current Setting 1 Adjust using wheel

6 Proximity Indicator 7 Stimulating Frequency Setting Adjust using Enter / Hz width button

Pulse Width Setting 2 Adjust using Menu / Pulse width button

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2.1a) Adjusting the Current in LOC mode 1

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0.6 - 2.0mA Default 0.2mA 2.0 - 5.0mA Default 0.5mA

Current Mode Options: Linear Mode, Non-Linear Mode Default: Linear

Increments can be adjusted in the Setup Menus

Linear Mode:

Circle the Wheel to adjust current.

The Linear Mode is called linear because one ‘click’ on the Wheel will correspond with one Non-Linear Mode: increment as set in the specific current range. The Linear Mode allows the user to selectNMS 450X individual incrementing options for the three different current ranges. The Non-Linear Mode facilitates the non-linear nature of the current intensity versus the distance from the nerve. This mode allows the user to define 20 adjustment positions in Default Current range: terms of Current (mA) and Pulse Width (ms). If correctly implemented each adjustment 0.00 - 5.00mA adjustable in the following default increments: position should afford the user with a relatively linear progression in terms of the distance 0.0 - 0.6mA Default 0.1mA from needle tip to the nerve. 14

Default Current and Pulse Width Range: As shown in table 1 in section 4.4 circle the Wheel to select the predetermined current and pulse width positions sequentially.

NOTE: Because the 20 definable positions include both current and pulse width settings, pulse width cannot be adjusted independently in this mode. This is indicated on the screen by the fact that pulse width is not highlighted.

When using the Nerve Mapping Probe (NMS 410/450X): 3 Warning: Notifies the user of a discrepancy between current setting and average current of actual stimulus. 4 If sound is enabled: STIMPOD will beep every time that a stimulus was delivered. The pitch of the sound will follow the current intensity level. 5 Average current of actual stimulus

Current Setting 1 Adjust using wheel

6 Proximity Indicator 7 Stimulating Frequency Setting Adjust using Enter / Hz width button

Pulse Width Setting 2 Adjust using Menu / Pulse width button

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2.1b) Adjusting the Current in MAP mode 1

NOTE: The STIMPOD will automatically default to the Nerve Mapping current range (0-20mA) and display the ‘ MAP ’ indicator.

Current Range: 0 - 20mA adjustable in 1mA increments. Circle the Wheel to adjust current.

NMS 450X

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2.2) Adjusting the Pulse Width 2

2.4) Adjusting the Twitch Frequency 7

Options: 0.05ms, 0.1ms, 0.3ms, 0.5ms, 1ms Default: 0.05ms Press Menu/Pulse Width button to toggle between different Pulse Widths.

Options: 1Hz, 2Hz, 5Hz Default: 2Hz Press Enter/Hz button to toggle between different stimulating frequencies.

2.3) Proximity Indicator 6 This is only relevant for Locating Mode The proximity indicator notifies the user that the target charge range has been reached. This function allows the user to set up an upper and lower limit of charge. When contraction is elicited at the set charge, this indicator should indicate to the user that the needle has reached the desired proximity to the nerve. This proximity is indicated both visually and audibly. Visual Indication: • Visually indicated in the diagnostics screen by two arrowheads. • Arrowhead indicating the lower threshold points upwards. • Arrowhead indicating the upper threshold points downwards. • The dotted line representing the selected current will be positioned between the two arrowheads if the target charge range is entered. Audible Indication: • A successful stimulus above the proximity range will make a single beep. • A successful stimulus within the proximity range will make a double beep. • A successful stimulus below the proximity range will make a triple beep.

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Neuromuscular Transmission Monitoring (NMT) Mode (NMS 450X)

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3.1) Introduction to NMT Monitoring

3.2) Cables and Sensors for NMT Monitoring

Monitoring Neuromuscular Blocking Agent involves stimulating a neural pathway which facilitates the contraction of an appendage. Based on the relative strength of the contraction which is the result of a stimulus of specific intensity or waveform, it is possible to draw conclusions about the efficacy of an injected Neuromuscular Blocking Agent.

The Stimpod NMS450X makes provision for two different sensor technologies for NMT Monitoring namely Acceloromyography (AMG) and Electromyography (EMG).

NMT Monitoring Cable (AMG) The Stimulation Modes used in NMT are as follows: Train-of-Four, Double Burst, Post Tetanic Count, Supra Maximal Current and Auto modes. •

These modes can be selected when a NMT Monitoring cable is inserted into the Stimpod.

In this case the NMT Monitoring Cable is fitted with a tri-axial accelerometer that is attached to the contracting appendage of the patient to measure the strength of the contraction resulting from the applied electrical stimulus. NMT Monitoring Cable (EMG) In this case the NMT Monitoring Cable is fitted with an EMG electrode that is attached to the contracting appendage of the patient to measure the action potential of the muscle due to the applied electrical stimulus.

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3.3) Stimulation Sites for NMT Monitoring Electrode placement relies on the cathode (black electrode clip) to be as close to the targeted nerve as possible in order to effectively depolarize the nerve. The anode (red electrode clip) should be away from the targeted nerve. Anatomical stimulation sites are chosen based on • • •

Their accessibility during surgery The ability to observe the neuromuscular response The nerve should be a suitable distance from the responding muscle to prevent direct muscle stimulation

Stimulation Sites Suitable for AMG AMG: Anatomically Ideal Stimulation Sites Targeted Nerve Affected Muscle Ulnar nerve adductor pollicis muscle flexor halluces brevis muscle Posterior tibial nerve Facial nerve (Zygomatic orbicularis oculi muscle Branch) Facial nerve (Temporal Branch) corrugator supercili muscle

Contracting Appendage Thumb Big toe Eye lid Eye brow

Stimulation Sites Suitable for EMG EMG: Anatomically Ideal Stimulation Sites Targeted Nerve Affected Muscle Ulnar nerve adductor pollicis muscle

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Contracting Appendage Thumb

3.4) AMG Patient Setup 1

Check Batteries & Switch Device On

2

Connect NMT Monitoring Cable (AMG)

3

Prepare Skin for Monitoring

Power on device

Patient Setup

4

Attach Electrodes

A M G

5

Secure Clips to the electrode

6

Attach Accelerometer to appropriate patient appendage

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3.5) EMG Patient Setup 1

Check Batteries & Switch Device On

2

Connect NMT Monitoring Cable (EMG)

3

Prepare Skin for Monitoring

Power on device

Patient Setup

4

Attach EMG Electrode

E M G

5

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Connect EMG Electrode to NMT Monitoring Cable (EMG)