Digitimer
Research and Clinical Instruments Manufacturer & Supplier
Acquisition InterfacesNational Instruments USB-6341-BNCHEKA LIH 8+8 Data Acquisition SystemAmplifiersNeuroLog SystemD360 8-Ch. EP/EEG/EMGD360R 4 Channel Isolated Research Amplifier/FilterD440 2/4 Ch. EMG/EPHEKA EPC10 Patch ClampHEKA EPC10 2/3/4 Ch. Patch ClampHEKA EPC800 Patch ClampAnti-vibration SystemsThorLabs Science DesksNarishige ITS Anti-vibrationNarishige Double MagnetNarishige SBP-2 BaseplateCell InjectorsPLI-100A Pico-injectorPLI-10 Pico-injectorNarishige IM-11-2Narishige IMS-20Narishige IM-21Narishige IM-400Injection Accessories
Incubators & ChambersAutomate Perfusion ChambersMedical Systems MicroincubatorsSSD Brain Slice KeepersSSD Brain Slice ChambersIontophoretic DevicesD380 Dye MarkerMains Noise EliminatorsHumBug Noise EliminatorD400 2/4Ch. Mains Noise EliminatorManipulatorsElectrophysiology System ManipulatorsInjection System ManipulatorsStereotaxic Manipulators“YOU” Compact ManipulatorsChronic ManipulatorsAccessoriesMicroscope Adaptors (Ephys)Microscope Adaptors (Injection)
MEA SystemsMED64 – BasicMED64 – Quad IIMED64 – AllegroMED64 – Plex 4/8MED64 – PrestoMED64 – Mobius SoftwareMED64 ProbesPerfusion EquipmentPerfusion SystemsPerfusion AccessoriesPipette FabricationMicropipette PullersMicroforges & MicrogrindersReplacement PartsCapillary GlassProgrammers & TimersDG2A Train Delay GeneratorNeuroLog System
Signal GeneratorsTG315 Function GeneratorSoftwareQtracW Threshold TrackingAutoMate EasycodeHEKA Chartmaster SoftwareHEKA Patchmaster SoftwareHEKA Fitmaster SoftwareStimulatorsDS2A Constant VoltageDS3 Constant CurrentDS4 Biphasic Constant CurrentDS5 Bipolar Constant CurrentDS7A/DS7AH Constant CurrentDS7R Constant Current ResearchDS8R Biphasic ResearchD121-11 Mounting FrameD185 Transcranial MultiPulseD330 MultiStim SystemNL800A Current Stimulus Isolator
A/D Interface ModulesNL201 – Spike TriggerNL601 – Pulse IntegratorAmplifier ModulesNL100AK – HeadstageNL100RK (NL100AKS & NL100C)NL102G – DC PreamplifierNL104A – AC PreamplifierNL106 – AC/DC AmplifierNL108A – Pressure AmplifierNL109 – Bridge AmplifierNL120S – Audio AmplifierNL820A – 4-Ch. IsolatorNL844 – 4-Ch. AC PreamplifierAnalogue ModulesNL254 – RatemeterNL506 – Analogue SwitchNL703 – EMG Integrator
Digital ModulesNL405 – Width/DelayNL501 – Logic GateNL505 – Flip FlopNL603 – CounterNL730 – Pulse ShiftFilter & Conditioner ModulesNL125/6 – Band-Pass FilterNL134/5/6 – 4-Ch. Low Pass FiltersNL143 – 3-Ch. Difference AmplifierNL144 – 4-Ch. High Pass FilterNL530 – Signal ConditionerNL540 – Inverting Attenuator (Alt. Gain)Generator ModulesNL301 – Pulse GeneratorNL304 – Period GeneratorNL412 – Pulse
NeuroLog AccessoriesAccessory KitsAdaptors & Adaptor CablesSockets (for cable mounting)Sockets (for panel mounting)Plugs (for cable mounting)Extension CablesCablesElectrode HoldersMiscellaneous AccessoriesNeuroLog System CasesNL900D – NeuroLog System CaseNL905 – Compact NeuroLog System Case
Pressure Transducers & AccelerometersPressure TransducersForce TransducersAccelerometersStimulator ModulesNL510 – Pulse BufferNL512 – Biphasic BufferNL800A Constant Current Stimulus Isolator Application NotesSignal AmplificationTriggering & Pulse GenerationSignal Conditioning Filtering & ProcessingElectrical Stimulation
Isolated Amplifiers for EMG/EEG/EP D440 2/4-Ch. EMG AmplifierD360 8-Ch. Patient Amplifier D360R 4-Ch. Research AmplifierAmplifier Accessories D175 Electrode Impedance Meter D179 Performance Checker D360 Audio Interface D360 USB to Serial Adaptor D177 Bio-Feedback Unit
Peripheral Stimulators DS5 Isolated Bipolar Constant Current Stimulator DS7A & DS7AH HV Constant Current Stimulator DS7R HV Constant Current Research Stimulator DS8R Biphasic Constant Current Stimulator
Transcranial Cortical StimulatorsD185 MultiPulse Cortical Electrical StimulatorStimulator AccessoriesD188 Remote Electrode SelectorElectrode Connection HeadboxesTrigger CablesElectrode HandlesMiscellaneous Items
Neurodiagnostic AccessoriesIntraoperative Neuromonitoring (IONM) Electroecephalography (EEG) Electromyography (EMG)Nerve Conduction Study (NCS) Evoked Potential (EP)Axelgaard Stimulation ElectrodesTouch Proof Plugs Adaptors & Electrode Linkers
Cath SecureCATH-SECURE – OriginalCATH-SECURE – ExtendedCATH-SECURE PlusCATH-SECURE – Dual TabCATH-SECURE For KidsNG SECURE
PessariesPessary Ring Sizing KitsCerclage Pessary (Perforated)Cerclage Pessary (Non Perforated)Ring PessaryThick Ring PessaryCube Pessary (Perforated)Cube Pessary (Non-Perforated)Vaginal DilatorUrethra PessaryBowl PessaryUrethra Bowl PessarySieve Bowl PessaryHodge PessaryClub PessaryTandem Pessary (Perforated)Tandem Pessary (Non-Perforated)
Urodynamic ConsumablesUrodynamics CathetersPump Infusion SetsTransducer Pressure DomesFemale Voiding AdaptorDuckbill ValvesSetguards3-Way Taps
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£2,254.00 exc. VAT
Manufacturer's Net List Price
The NL844 is a small, four channel, low noise, high impedance, differential pre-amplifier designed for electromyography (EMG) or evoked potential (EP) use close to the preparation or human subject. The unit is intended for use with the NL820A Isolator, from the NeuroLog™ system. It has controls for LF-cut, Gain and Impedance checking of each amplifier electrode. The front panel inputs use 1.5mm DIN 42802 safety connectors. This unit is particularly suited for use where there are very large stimulus artefacts, for example when used close to a magnetic stimulator coil. In these cases the stimulus artefact would normally swamp the pre-amplifier inputs resulting in a ‘tail’ with a long time constant that obliterates the response. The special circuitry of the NL844 eliminates this as long as good recording practice is followed. The input circuit automatically adjusts to the DC input conditions and a non-linear filter subsequently modifies its time constant if the differential input signal exceeds its normal ±20mV working range. Therefore fast, short artefacts do not block the subsequent stages. This results in an amplifier with a very fast recovery time from stimulus artefact pulses.
Each channel has a connector for the non-inverting (+) input that is often called the ‘Reference’ on EEG machines and inverting (-) input that is often called the ‘Active’ on EEG machines. As the amplifier is differential both must be used on active channels. The ‘COM’ connector must always be connected to the patient to provide a reference potential for the amplifiers. A deblock button provides the user with a method of removing any DC potential from the internal coupling capacitors that may occur whilst arranging the electrodes on the patient. This function can also be performed remotely via the ‘MUTE’ socket on the NL820A.
As well as amplifying 4 channels, the unit can also be operated in a single or two channel mode (channels 1 & 3 or 2 & 4). The NL844 needs to be connected to the NL820A Isolator module. NL844 4 Channel Preamp’s are ideally suited as a multi-channel EMG amplifiers or EEG amplifiers.
Get in touch with our knowledgeable staff to learn more about the NL844 AC Preamplifier in more detail. Call 01707 328347 to contact us or email us at sales@digitimer.com. Our expert team can answer any questions and queries you have regarding the NL844, as well as providing additional information on our complete collection of products.
Product Information
NL844 4Ch AC Pre Amplifier
References Publications which cite use of the Digitimer Neurolog System can be found on Google Scholar.
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