Neurosign V4

Neurosign V4

Neurosign has a reputation for producing simple reliable and cost-effective nerve monitors. Neurosign® V4 Intraoperative Nerve Monitor continues this tradition, but uses modern technology to deliver a 4 or 8-channel intraoperative nerve monitoring solution – helping surgeons to preserve that nerve!

3 key presses and you are running and ready!

Main unit

Screen                                       15” Colour LCD, 1024 x 768 pixels


  Bar graph range                       30µV – 30mV peak to peak

  Bar graph resolution                 16 segments, logarithmic

  Waveform amplitude ranges     ±25µV, ±50µV, ±100μV (default), ±200µV, ±500µV, ±1mV, ±2.0mV, ±5mV, ±10mV, ±20mV, ±30mV

  Accuracy                                  2% of FSD

  Waveform time base ranges     12.5ms, 25ms (default), 50ms,

                                                 100ms, 500ms, 1s, 5s, 10s

  Accuracy                                  2% 12.5ms-1s; 5% 5s; 10% 10s.

  Time base cursor accuracy       2%

Software                                  See “6.4. System Details” on page 47

Rotary actuators                     3:

Left dial                                 – 1. stimulator stimulation setting (STIM1)

 Right dial                              – 2. stimulator stimulation setting (STIM2)

Centre dial                             – EMG response audio volume (Master Volume)

External connections              EMG Amplifier Module (Pre-amplifier)

                                                 Trigger In  

                                                 Trigger Out – Open Drain   

                                                 Mute sensor   


EMG Audio                               8.4W rms (95dBa @ 1m)

Stimulator pod

 Primary Stimulator

  Operational mode                     Constant Current or Constant Voltage

  Current ranges                         10µA – 10mA, in steps dependent on procedure.

  Accuracy                                  ±5%, into 1kΩ load

  Voltage                                    10mV – 10V, in steps dependent on procedure.

  Accuracy                                  ±5%, into 1kΩ load

  Voltage/current confirm           ≥ 85% of set point

  Stimulating pulse                     Square wave negative going

  Width                                      100µs, 200µs (default), 300µs, 400µs, 500µs

  Repetition frequency                3Hz, 30Hz

  Probe connections                    2

Secondary stimulator                 Not currently available – contact us for further information.


Monitoring channels                    4

Signal input range                      ±5µV to ±40mV

Common mode rejection ratio     > 90dB (@ 50/60Hz)

Bandwidth                                  10Hz – 1kHz (-3dB points)

Noise                                         <20µV rms (Input referred) 

Notch filter                                 50Hz, 60Hz, off


General Specification

Power                                        100V-230V ~50/60Hz; 75VA

Dimensions                                790mm wide, 400mm deep, 1600mm high

Weight                                      24Kg

Maximum load permitted            1.5kg

Total maximum weight               25.5kg

Environmental conditions:

Operational ranges:

  Ambient temperature:              5°C to 40°C

  Relative humidity:                    10% to 80% (non-condensing)

  Atmospheric pressure:             70kPa to 106kPa

Transport and storage ranges:

  Ambient temperature:              -19°C to 60°C

  Relative humidity:                    10% to 80% (non-condensing)

  Atmospheric pressure:             50kPa to 106kPa


4 or 8 channel amplifier:

Software upgrade via SD card. Put the new software release on the card. Put it in the SD port of V4 and turn the system on. Automatic update will start and the system will restart after this. This can be done for system, amplifier and stimulator if needed.