 NMS410
 Operation Modes:
Nerve Locating Mode
Current Range: 0.00 – 5.00mA ±0.05mA, adjustable in pre-set increments.
Pulse Width Options: 50μs, 100 μs, 300 μs, 500 μs, 1000 μs
Stimulus: Monophasic square wave
Stimulating Frequency: 1Hz, 2Hz and 5Hz
Nerve Mapping Mode
Current Range: 0 – 20mA ±0.5mA, adjustable in 1mA increments.
Pulse Width Options: 50μs, 100 μs, 300 μs, 500 μs, 1000 μs
Stimulus: Monophasic square wave
Stimulating Frequency: 1Hz, 2Hz and 5Hz
 Waveform:
Constant Current Monophasic Square wave
 Technical Specifications:
Device Classification: Class IIa, Type BF
Power Supply: 4x AAA alkaline batteries
Power Consumption: 17mA
Maximum Stimulation Voltage:
Nerve Locating 100V
Nerve Mapping 400V
Weight: 130g
Dimensions: 145mm x 90mm x 30mm
Load Impedance: 0 – 15 kOhm (Nerve Map)
 Nerve Mapping Probe 410
Ergonomically designed cutaneous Nerve Mapping Probe
 Contents NMS410
STIMPOD Neuromuscular stimulator
Nerve Locating Cable
Nerve Mapping Probe
Instructions for Use
Carry Case (Optional)
Note: Needles, ECG electrodes and batteries are not supplied

 

NMS450
 Operation Modes:
Nerve Locating Mode
Current Range: 0.00 – 5.00mA ±5%, adjustable in pre-set increments.
Pulse Width Options: 50μs, 100 μs, 300 μs, 500 μs, 1000 μs
Stimulus: Monophasic square wave
Stimulating Frequency: 1Hz, 2Hz and 5Hz
Nerve Mapping Mode
Current Range: 0 – 20mA ±5%, adjustable in 1mA increments.
Pulse Width Options: 50μs, 100 μs, 300 μs, 500 μs, 1000 μs
Stimulus: Monophasic square wave
Stimulating Frequency: 1Hz, 2Hz and 5Hz
NMBA Monitoring Mode
Current Range: 0 – 80mA ± 5%, adjustable in 1mA increments.
Pulse Width Options: 200 μs
Stimulating Modes: Train of Four, Twitch, Double, Burst, Post Tetanic Count, Tetanus
Tetanus Frequency: 50Hz, 100Hz
Twitch Frequency: 1Hz, 2Hz, 5Hz, 50Hz and 100Hz
 NMBA detail
‘TWI’ – Twitch
A single monophasic square wave with amplitude and pulse width, as defined by the current amplitude (mA) and Pulse Width (μs) settings. It will repeat at either 1Hz or 2Hz

In NMBA Monitoring mode, the Single twitch can be used to compare the response to the base or control response.
Twitch is also used for nerve mapping and nerve locating. A repeated twitch at a 2Hz frequency is preferred for this application.

 

‘TOF’ – Train of Four
A Train of Four refers to 4 monophasic square wave pulses (as described under twitch). These 4 pulses stimulate at 2Hz. This mode can be used in conjunction with the Accelerometer as a feedback device.

‘DB’ – Double Burst
A Double Burst refers to 2 bursts of three monophasic square wave pulses (as described under twitch). These three pulses stimulate at 50Hz, and the two groups of pulses are 750ms apart. This mode can be used in conjunction with the Accelerometer as a feedback device.

At the other end of the relaxant scale the anaesthetist may need to ensure that the neuromuscular block has worn off. Double Burst is more sensitive than TOF or single twitch.
Fade in the TOF can be difficult to detect in minor block. The middle 2 twitches make it difficult to compare the first and the last.
Double Burst stimulation consists of two sets of twitches that are separated by a brief interval to improve perception of fade. (The first twitches and the brief pause are designed to prevent facilitation occurring between the first and second burst.)
‘TET’ – Tetanus
Tetanus refers to a single Twitch as defined above, repeating at a 50Hz or 100Hz rate.

This is fast rate stimulation (50Hz/100Hz) which causes a continuous tonic contraction of the muscle. Post-tetanic facilitation is a characteristic of the non-depolarizing drugs. (Non-depolarizing drugs are generally used in the latter part of an operation). The facilitation feature is when following a tetanic stimulation; the response to single stimulations is increased. Tetanic stimulation is usually applied in deep relaxation to estimate the time required before recovery begins.
In deep relaxation a single twitch and train-of-four stimulus will not cause a muscle contraction and thus a tetanus stimulus should be used. The tetanus stimulation will improve the muscle’s response by a fixed factor. Therefore during deep relaxation an evaluation of the neuromuscular block can again be made using standard stimulation patterns after a tetanic stimulation has been used.
In clinical practice, stimulation at 50Hz is normally applied for 5 seconds.
To allow the neuromuscular junction to recover, it has been recommended that the TET pattern should not be repeated more often than every 2 minutes.
‘PTC’ – Post Tetanic Count
Post Tetanic Count is used when no response is found with Train of Four and Double Burst. A 50Hz Tetanus is initiated for five seconds, in order to lower the triggering threshold of the nerve. This is followed by a pause of 3 seconds, and then 20 Twitches. The number of Twitches for which a response can be observed, serves as an indication of the depth of the Neuromuscular Block. This mode can be used in conjunction with the Accelerometer as a feedback device.

The Post Tetanic Count was developed to allow the control of deep blockade, where there is no twitch response to Twitch or TOF stimulus (when using non-depolarizing drugs only). After a period of rapid stimulation (tetanus) the nerve cells ‘gear up’ for action. After a brief pause the twitch height will be increased above baseline for that degree of block.

The following is the way that a Post Tetanic Count is used. Relaxant is gradually given until no twitch or TOF responses are visible. In PTC mode a burst of tetanus is delivered, a pause will follow, and then a sequence of 20 twitches will be delivered. The anaesthetist simply counts how many twitches are visible. When only 1 or 2 twitches are visible the block is deep enough for virtually any surgery.
PTC should not be repeated more often than every 2 minutes otherwise spurious recovery will be indicated. NB: PTC also detects FADE, i.e. during the single twitches/pulses following the tetanus burst.
 Waveform:
Constant Current Monophasic Square wave
 Technical Specifications
Device Classification: Class IIa, Type BF
Power Supply: 4x AAA alkaline batteries
Power Consumption: 30mA
Maximum Stimulation Voltage: NMS450 – 400V
Weight: 130g
Dimensions: 145mm x 90mm x 30mm
Load Impedance: 0 – 20 kOhm (Nerve Locate)
0 – 20 kOhm (Nerve Map)
0 – 5 kOhm (NMBA Mode)
 Accelerometer (NMS450)
High Resolution Tri-axial Accelerometer
Real-time diagnostics
 Nerve Mapping Probe
Ergonomically designed cutaneous Nerve Mapping Probe
 Contents NMS450
STIMPOD Neuromuscular stimulator

NMBA Monitoring Cable
Nerve Locating Cable

 

Nerve Mapping Probe
Accelerometer (Optional)
Instructions for Use
Carry Case
Note: Needles, ECG electrodes and batteries are not supplied
For ordering NMS450 kits see –SERVING TOOLS & SPARE PARTS–
 Common features of the NMS4xx series
 Stimulation cables
Locating Cable
Mapping and locating cable
NMBA cable with Accelerometer (Only available on the NMS450 model)
 LCD module Type Dimensions (L x W x H in mm) Monochrome dot matrix 128×64 dots, white backlight 80 x 6.5 x 54
 Environmental conditions
Temperature Environmental condition Degrees Celsius Operating Temperature 10 – 40 Degrees Celsius (°C) Storage and Transport Temperature 0 – 50 Degrees Celsius (°C)
Humidity
Relative humidity range is 5% to 90%.
Any submersion of the Stimpod will cause permanent damage. Long-term high humidity will cause condensation and as a result will cause permanent damage because of corrosion.
RoHS
This device uses RoHS complaint components and lead-free soldering process.