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

Indications for Spinal procedures which may use NIM 3.0 EMG monitoring include:

Degenerative Treatments, Pedicle Screw Procedures, Fusion Cages, Rhizotomy, Orthopedic Surgery, Open and Percutaneous Lumbar and Cervical Surgical Procedures, and Thoracic Surgical Procedures.




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.


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



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.


If paralyzing anesthetic agents have been used, patient must regain muscle activity prior to use of the NIM-Neuro/Response 3.0 EMG Monitor.

  1. To limit the paralytic effect of anesthetic agents, the anesthesiologist should monitor Train-of-Four (TOF) to prevent diminished EMG activity. Consult anesthesiologist if EMG changes are observed.


Surgical Identification of exposed Neural structures is key to their preservation. Failure to use Nerve Stimulation Probe may contribute to unintended surgical nerve damage or resection.


To avoid the risk of fire or explosion, do not use the Medtronic NIM System in the presence of flammable anesthetics and/or oxygen rich environment.


After each procedure, properly clean and disinfect all reusable system components


To avoid alternate site patient burns or lesions:

  1. Do not activate the electrosurgical instruments (ESU) while stimulator is in contact with tissue.
  2. Do not leave dissection instruments, stimulating electrodes, or probes in surgical field.
  3. Do not store dissection instruments, stimulating electrodes, or probes in electrosurgical instrument holder.
  4. Do not allow a second surgeon (for example, fat harvesting) to use electrosurgical instruments while stimulator is in use.
  5. Do not activate electrosurgical instrument for prolonged periods while ESU is not in contact with tissue.
  6. Do not activate electrosurgical instrument near the recording or stimulating electrodes.
  7. Do not allow patient interface boxes or recording / stimulating electrodes sites to be flooded with saline.
  8. Do not allow excessive stray AC or DC leakage currents from patient connected equipment; Avoid creating an unintended grounding path through applied electrodes.

 Practitioner is responsible for proper use, periodic safety certification of patient connected equipment, and AC power grounding in accordance to the appropriate IEC 60601-1 and/or IEC 60601-1-1 medical safety standard.


Disconnect power to the console before cleaning the unit to avoid electrical macro shock.


Achieve electrical grounding reliability with proper connections. Connect the console to hospital grade receptacles only.


DO NOT use any parts other than Medtronic Xomed, Inc. components as damage or substandard performance could result.


This medical device complies with IEC/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.


It is important that the NIM-Neuro/Response 3.0 operator be familiar with this manual, its precautions, procedures and safety issues.


To avoid electrical shock, do not attach unapproved components or accessories to the Medtronic NIM System.


All service must be performed by Medtronic qualified personnel only.


Do not directly contact active, implanted devices with the stimulator as it may disrupt the implanted device’s operation. Consult medical specialist before use.


Electrocardiogram monitoring artifacts may be caused by Medtronic NIM stimulus current delivery or EMG electrode impedance monitoring.


Use of unapproved stimulators, stimulus probes, stimulus dissection instruments or electrodes may result in compromised Medtronic NIM operation, such as, but not limited to decreased accuracy.


Repair and/or modification to the Medtronic 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.


To avoid the risk of infection, the user must maintain good sterility practices.


W19 False negative responses (failure to locate nerve) may result from:

  1. Shorted EMG electrode or cabling (conductive parts of applied needle electrodes or cables contacting each other).
  2. Patient Interface fuse blown and not detected (32 mA, 250 V. Xomed Part No.: 8253075).
  3. Patient Interface defective.
  4. Inadequate stimulus current.
  5. 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.
  6. Simultaneous stimulation of the nerve and the surrounding tissue, resulting in current shunting (inadequate delivery of stimulus current to target nerve tissue).
  7. Flatline on the EMG channel caused by shorted internal amplifier (characterized by baseline activity of < 3 μV peak-to-peak).
  8. EMG electrodes not positioned properly in the target muscles.


Stimulator current may cause involuntary patient movement resulting in patient injury.


If the incrementing probe handle malfunctions, it could result in increased current delivery to the patient. Immediately disconnect the Control Plug from the Patient Interface box and use the console to adjust stimulus current.


Be careful not to damage vascular or neural structures when preparing the nerve for the installation of the APS Electrode.


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 the system indicates improper electrode impedance, consult the Troubleshooting topic for impedance value troubleshooting.


Remove APS electrode from patient prior to using external defibrillator to prevent thermal injury to patient at APS electrode site.


Operation in close proximity to high frequency (shortwave or microwave) equipment may produce instability in the electrical stimulator output.


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 (Neurophysiologist) attention is required for stimulus levels which exceed default settings or conditions. Levels higher than 2 mA RMS/ cm2 (3 mA) for Slim Prass Probe and Prass Bipolar Probe may result in tissue damage.


Do not perform Magnetic Resonance Imaging (MRI) on a patient with electrodes, probes, and EMG tubes in the field. The effect of MRI is unknown on these devices.


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



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.



Portable and mobile RF including cell phones and communications equipment can affect Medical Electrical Equipment. 


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


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.


Inability to deliver stimulus current flow may be caused by inadvertent simultaneous current delivery from both STIM probe outputs, resulting in current shunting.


Avoid accidental contact between ‘PATIENT APPLIED PARTS’ and other conductive parts including those connected to protective earth.


The metal 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.


The muting detector is susceptible to damage from dropping. Visually inspect inner jaw surfaces for cracking, chipping or damage prior
to use. Insufficient muting may result.