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NIM

Nerve Monitoring Systems

Indications, Safety, and Warnings

NIM 3.0 Nerve Monitors

Indications for Use

The NIM® 3.0 is intended for locating and identifying cranial and peripheral motor and mixed motor-sensory nerves during surgery, including spinal cord and spinal nerve roots. The APS® electrode is an accessory intended for providing automatic periodic stimulation to nerves when used with the Medtronic Nerve Monitoring Systems.

Indications for NIM 3.0 EMG Monitoring Procedures include:

Intracranial, Extracranial, Intratemporal, Extratemporal, Neck Dissections, Thoracic Surgeries, and Upper and Lower Extremities

Contraindications

The NIM 3.0 is contraindicated for use with paralyzing anesthetic agents that will significantly reduce, if not completely eliminate, EMG responses to direct or passive nerve stimulation.

Warnings and Precautions

It is important that the NIM-Neuro 3.0 and NIM-Response 3.0 intended operators be familiar with the User's Guide: its Warnings, Precautions, procedures, and safety issues. Disregarding the information on safety is considered abnormal use.

Warnings

System Warnings

W1 After each procedure, properly clean and disinfect all reusable system components.
W2 To avoid the risk of fire or explosion, do not use the NIM System in the presence of flammable anesthetics and/or oxygen rich environment.
W3 Disconnect power to the NIM-Neuro®/Response® 3.0 Console before cleaning the unit to avoid electrical macro shock.
W4 Achieve electrical grounding reliability with proper connections. Connect the NIM-Neuro/Response 3.0 Console to hospital grade receptacles only
W5 DO NOT use any parts other than Medtronic Xomed, Inc. components as damage or substandard performance could result.
W6 This medical device complies with EN60601-1-2 safety standard for electromagnetic compatibility, requirements and test. However, if this equipment is operated in the presence of high levels of electromagnetic interference (EMI) or highly sensitive equipment, interference may be encountered and the user should take whatever steps are necessary to eliminate or reduce the source of the interference. Diminished performance may lengthen operating time for anesthetized patient
W7 It is important that the NIM-Neuro®/Response® 3.0 operator be familiar with this manual, its precautions, procedures and safety issues
W8 To avoid electrical shock, do not attach unapproved components or accessories to the NIM System.
W9 All service must be performed by Medtronic qualified personnel only.
W10

To avoid patient burns:

  • a. Do not activate the electrosurgical instruments while stimulator is in contact with tissue.
  • b. Do not leave stimulating electrodes or probes in surgical field.
  • c. Do not store stimulating electrodes or probes in electrosurgical instrument holder.
  • d. Do not allow a second surgeon to use electrosurgical instruments while stimulator is in use.
W11 Direct stimulator contact may disrupt the operation of active implanted devices. Consult medical specialist before use.
W12 Electrocardiogram monitoring artifacts may be caused by NIM stimulus current delivery or EMG electrode impedance monitoring.
W13 Use of unapproved stimulators, stimulus probes, stimulus dissection instruments or electrodes may result in compromised NIM operation, such as, but not limited to decreased accuracy
W14 Repair and/or modification to the NIM or any accessory by anyone other than qualified service personnel may significantly compromise the unit’s ability to monitor nerve activity and/or void the equipment warranty
W15 The NIM does not prevent the surgical severing of nerves. If monitoring is compromised, the surgical practitioner must rely on alternate methods, or surgical skills, experience, and anatomical knowledge to prevent damage to nerves.
W16 If paralyzing anesthetic agents have been used, patient must regain muscle activity prior to use of the NIM-Neuro/Response 3.0 EMG Monitor.
W17 To avoid the risk of infection while using the NIM Stylus, the user must maintain good sterility practices.
W18

False negative responses (failure to locate nerve) may result from:

  • a. Shorted EMG electrode or cabling (conductive parts of applied needle electrodes or cables contacting each other).
  • b. Patient Interface fuse blown (32 mA, 250V. Xomed Part No.: 8250615).
  • c. Patient Interface defective.
  • d. Inadequate stimulus current.
  • e. Inadequate current for stimulation of nerve through hardware, such as stimulus dissection instruments, may vary based on the physical size, shape characteristics, and design of the hardware and proximity to the nerve.
  • f. Inadvertent simultaneous current delivery from both Stimulator (Patient Interface) probe outputs. This may result in current shunting, division between the stimulator probes.
  • g. Shorted internal amplifier (characterized by baseline activity of < 3 μV p-p).
W19 Stimulator current may cause involuntary patient movement resulting in patient injury.
W20 Anesthetic agents used may have an effect on the EMG amplitude.
W21 Be careful not to damage vascular structures when preparing the nerve for the installation of the APS Electrode
W22 EMG amplitude may be affected by anesthesia regimen used. Consult anesthesiologist if EMG changes are observed.
W23 Electrode integrity should be checked after electrode insertion and before electrode removal to give additional assurance that electrode continuity was maintained throughout the entire procedure. If electrode impedance is very high, discontinue use and replace.
W24 Remove APS electrode from patient prior to using external defibrillator to prevent thermal injury to patient at APS electrode site.
W25 Avoid trans-thoracic stimulation; when possible, maintain anode and cathode stimulating sites in close proximity.
W26 Operation in close proximity to a shortwave or microwave therapy equipment may produce instability in the electrical stimulator output.
W27 Safe stimulus levels are dependent on various conditions including but not limited to: type of excitable tissue, Charge Per Pulse, and Charge Per Unit Area. Waveform morphology, repetition rate, and stimulator effective surface area must be considered. Special operator attention is required for stimulus levels which exceed default settings or conditions resulting in levels higher than 2 mA RMS/cm2.

Precautions

P1. Medical electrical equipment needs special precautions regarding EMC and needs to be installed and put into service according to the EMC information provided in the User's Guide.

P2. Portable and mobile RF communications equipment can affect medical electrical equipment.

P3. Use of accessories and cables other than those specified and sold by Medtronic may result in increased emissions and decreased immunity of this unit.

P4. The NIM-Neuro/Response 3.0 should not be used adjacent to or stacked with other equipment. If adjacent or stacked use is necessary, the NIM-Neuro/Response 3.0 should be observed to verify normal operation in the configuration in which it will be used.

P5. Loud extraneous monitoring noise is caused by activation of electrosurgical unit. Muting Detector must be properly attached to the active electrosurgical lead.

P6. Inability to deliver stimulus current flow may be caused by inadvertent simultaneous current delivery from both STIM 1 probe outputs. This may result in current shunting, division between the stimulator probes.

P7. Avoid accidental contact between 'PATIENT APPLIED PARTS' and other conductive parts, including those connected to protective earth.

P8. The NEW Muting Probe (Ref - 8220325) is compatible with previous versions of the NIM. However, previous versions of the Muting Probe are NOT compatible with the NIM 3.0 System.

Expand All

NIM 2.0 NERVE MONITORS

NIM 2.0 Nerve Monitors

Indications

This device is intended for use in surgical procedures for patient-connected intraoperative nerve monitoring, ie, assisting the surgeon in locating and mapping motor nerves through the use of electromyographic (EMG) signals and electrical stimulus of nerves. This device is indicated for locating and identifying cranial and peripheral motor nerves during surgery.

Contraindications

The use of paralyzing anesthetic agents will significantly reduce, if not completely eliminate, EMG responses to direct or passive nerve stimulation. Whenever nerve paralysis is suspected, consult an anesthesiologist.

Warnings

W1 The NIM-Neuro™ 2.0 does not prevent the surgical severing of nerves. If monitoring is compromised, the surgical practitioner must rely on alternate methods, or surgical skills, experience, and anatomical knowledge to prevent damage to nerves.
W2 To avoid patient burns:
W2a Do not activate electrosurgical Instrument while the stimulator is in contact with tissue.
W2b Do not leave stimulating electrodes or probes in surgical field.
W2c Do not store stimulating electrodes or probes in electrosurgical Instrument holder.
W2d Do not allow a second surgeon (ie, fat harvesting) to use electrosurgical instrument while stimulator is in use.
W2e Special operator attention may be required for stimulus currents exceeding 2 mA RMS/cm2. The RMS value of current is generally lower than the stimulator current setting in mA. To calculate RMS current, waveform morphology, pulse width, repetition rate, and the stimulator current delivered must be considered.
W3 While Muting is activated, auditory and visual monitoring are disabled.
W4 To avoid false negative responses, verify stimulator current setting is high enough, and verify stimulus delivery by tone, voice, or display. Low stimulator current may cause a false negative response.
W5 High stimulator current may cause involuntary patient movement resulting in patient injury.
W6 High stimulator current activating of the fifth cranial nerve or Mastication muscles may cause tongue lacerations.
W7 False negative responses (failure to locate nerve) may result from:

W7a Shorted EMG electrode or cabling (conductive parts of applied needle electrodes or cables contacting each other).
W7b Patient Interface fuse blown (32 mA, 250V. Xomed Part No.: 8250615).
W7c Patient Interface defective.
W7d Inadequate stimulus current.
W7e Inadequate current for stimulation of nerve through hardware, such as stimulus dissection instruments, may vary based on the physical size, shape characteristics, and design of the hardware and proximity to the nerve.
W7f Neuromuscular fatigue from prolonged or repeated exposure to electrical stimuli.
W7g Inadvertent simultaneous current delivery from both Stimulator (Patient Interface) probe outputs. This may result in current shunting, division between the stimulator probes.
W7h Shorted internal amplifier (characterized by baseline activity of < 3 μV p-p).
W8 Do not power-on the NIM-Neuro 2.0 when the stimulator is in the surgical field.
W9 To avoid eye injury during electrode placement, the electrode needles should be directed away from the globe and adequately secured with tape.
W10 To avoid the risk of fire or explosion, do not use the NIM-Neuro 2.0 in the presence of flammable anesthetics and/or oxygen rich environments.
W11 To avoid electrical shock, do not attach unapproved components or accessories to the NIM.
W12 To avoid the risk of infection while using the NIM-Neuro 2.0 touchscreen stylus, the user must maintain good sterility practices.
W13 Electrocardiogram monitoring artifacts may be caused by NIM-Neuro 2.0 stimulus current delivery or EMG electrode impedance monitoring.
W14 Direct stimulator contact may disrupt the operation of active implanted devices.
W15 While stimulating, it is recommended to use only approved EMG monitor(s) equipped with active audio and/or visual current delivered feedback systems to ensure delivery of current to intended tissues.
W16 Proper handling, insertion, and placement of electrodes and probes is critical for safe and accurate EMG monitoring:
W16a Improperly placed or bent needles increase the risk of needle breaking off in the patient.
W16b Do not attempt to straighten bent needles because this may cause stress and weaken device, causing needle to break off in patient.
W16c Extreme care must be taken when handling instruments with sharp points or edges.
W17 The surgical practitioner must choose the appropriate size electrodes and probes based on the procedure to be performed and the stimulating current necessary for the application.
W18 Avoid trans-thoracic stimulation; when possible, maintain anode and cathode stimulating sites in close proximity.
W19 Reuse of single use electrodes and probes increase the risk of infection and may cause degraded or ineffective monitoring.

Precautions

P1 Special care must be exercised to distinguish between the high-pitched beep of the Event Tones (EMG activity over threshold), and the Stimulus Warble Tone (indicates the set current is being delivered).
P2 When the “Bleedle Alarm” (BLEE-dle-DEET) sounds, the cause must be identified and eliminated immediately.
P3 To avoid loud, extraneous monitoring noise during electrosurgical unit activation, ensure the Muting Probe is properly attached to the active electrosurgical lead.
P4 Inadequate stimulus current flow may be caused by non-flush contact between the stimulating electrode or probe and the nerve, inadequate stimulator probe electrical contact surface area, or high impedance.
P5 Inability to deliver stimulus current flow may be caused by:
P5a Stimulator return electrode not connected, or other incomplete electrical connection between the NIM-Neuro 2.0, monitoring electrode and stimulator probe.
P5b STIM 1 (EMG) Patient Interface fuse blown (32 mA, 250 V, REF 8250615).
P5c Stimulus set to 0.00 mA.
P5d Defective stimulating electrode or probe.
P6 To avoid false positive EMG events (stimulus artifacts):
P6a Ensure the recording electrodes and the stimulator (+) or (-) cabling are routed separately and not tangled.
P6b Ensure EMG ground (green wire) is physically placed between the stimulator return electrode (white wire with red plug) and the EMG channel input electrodes.
P7 Proper placement and setup of the electrosurgical unit away from the NIM-Neuro 2.0 will reduce or minimize unnecessary muting, interference, and offsets.
P8 Use of unapproved stimulators, stimulus probes, stimulus-dissection instruments or electrodes may result in compromised NIM-Neuro 2.0 operation, such as, but not limited to, decreased accuracy.
P9 Electrode integrity should be checked (on the “electrodes” screen) after electrode insertion and before electrode removal to give additional assurance that electrode continuity was maintained throughout the entire procedure. If electrode impedance is very high, discontinue use and replace.
P10 The Patient Interface cable, and Muting Probe cable should be secured to the floor with tape or other nontrip device.
P11 Excessive or insufficient muting may result from improper muting gain. For excessive muting, move the Muting Probe to a Lower jack number. For insufficient muting, move the Muting Probe to Higher jack number. Standard position is number 3.
P12 To avoid excessive muting:
P12a Do not place the NIM-Neuro 2.0 in close proximity to the electrosurgical unit.
P12b Do not place Patient Interface or electrode wires in close proximity to the electrosurgical unit or electrosurgical unit wires.
P12c Avoid high-power electrosurgical unit monopolar settings. Note that muting caused by electrode charging may last several seconds after electrosurgical Instrument use.
P12d Be aware of external sources that may induce muting including cellular phones, diathermy, electrocautery used in adjacent operating rooms, or other sources of electromagnetic interference.
P13 Avoid accidental contact between connected but unapplied electrodes and other conductive parts.
P14 Contaminated single use electrodes and probes must be disposed of in an appropriate sharps biohazard container in accordance with hospital or other user facilities policy.
P15 For extra-ocular monitoring, it is recommended that electrode placement be done under the direction of a neurologist or ophthalmologist.
P16 The Patient Interface safety fuse used in all NIM Patient Interfaces Boxes for the Stimulator Output are specifically tested for ECU protection. Use Xomed 11270048 Fuse, 5 x20mm, 32mA, 250 V. Order 8250615 Fuse Kit for replacements.

Additional Precautions

AP1 To avoid system damage, do not connect any device other than NIM-Neuro 2.0 Muting Probes into any of the four muting probe inputs on the rear panel of the NIM-Neuro 2.0.
AP2 Disconnect the power of the NIM-Neuro 2.0 or a connected printer before cleaning. To prevent cleaning solutions from seeping into the electronic portions of the instrument, spray cleaner lightly on a cotton cloth, then wipe the instrument with the cloth. Be especially careful around the controls, connectors and panel edges. Do not use abrasive cleaners (especially on the touch screen).
AP3 Repair and/or modification to the NIM-Neuro 2.0, or any accessory by anyone other than qualified service personnel may significantly compromise the units ability to monitor nerve activity and/or void the equipment warranty. For best performance, it is recommended that all service be performed by Medtronic Xomed service personnel. The Manufacturing Test is not intended for end users and is to be used only under the direct supervision of Medtronic Xomed Personnel (see section 7.13).
AP4 Medical Electrical Equipment needs special precautions regarding EMC and needs to be installed and put into service according to the EMC information provided in this Guide.
AP5 Portable and mobile RF communications equipment can affect Medical Electrical Equipment.
AP6 Use of accessories and cables other than those specified and sold by Medtronic Xomed may result in increased emissions and decreased immunity of this unit.
AP7 The NIM-Neuro 2.0 should not be used adjacent to or stacked with other equipment. If adjacent or stacked use is necessary, the NIM-Neuro 2.0 should be observed to verify normal operation in the configuration in which it will be used.

NIM TRIVANTAGE EMG ENDOTRACHEAL TUBE

NIM EMG ELECTRODES AND PROBES (GENERAL)

NIM APS ELECTRODE

NIM INCREMENTING PROBE

STIM BUR GUARD

INTEGRATED POWER CONSOLE (IPC SYSTEM)

MIDAS REX LEGEND EHS STYLUS HIGH-SPEED SURGICAL DRILL

VISAO HIGH-SPEED OTOLOGIC DRILL

CURVED BURS

STRAIGHTSHOT M4 MICRODEBRIDER