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 IM-21Narishige IM-400Injection Accessories
Incubators & ChambersAutomate Perfusion ChambersMedical Systems MicroincubatorsSSD Brain Slice KeepersSSD Brain Slice ChambersIontophoretic DevicesD380 Dye MarkerMains Noise EliminatorsHumBug Noise EliminatorD400 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 SystemsStandard & Pressurized PerfusionSmartSquirt Micro-PerfusionIn Vivo Perfusion (Fixation)Heated PerfusionPipette 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 PessarySieve Bowl PessaryHodge PessaryClub PessaryTandem Pessary (Perforated)Tandem Pessary (Non-Perforated)
Urodynamic ConsumablesUrodynamics CathetersPump Infusion SetsTransducer Pressure DomesFemale Voiding AdaptorDuckbill ValvesSetguards3-Way Taps
Manufacturer's Net List Price
The DS2A Isolated Constant Voltage Stimulator is a low noise solution for electrical stimulation of in vivo and in vitro preparations, in order to excite neurons, nerves or muscle fibres. Battery powered and isolated from its trigger source and ground, the DS2A is designed to deliver precisely adjustable voltage pulses, without introducing noise into electrophysiological recordings. The DS2A will output monophasic voltage pulses of up to 100V, which are widely adjustable in pulse duration and amplitude.
As with our DS3 Constant Current Stimulator the output comes from self-contained alkaline batteries and the unit includes conveniently located battery test sockets. The DS2A can be triggered or “gated” on by a TTL compatible external device, including our DG2A Train/Delay Generator. The DS2A and DS3 also feature a polarity control switch and a front panel single-shot trigger button.
If desired, the DS2A can be installed into our 19″ rack mounting frame (D121-11) which can hold up to two DS2As or a DG2A and DS2A. To find out more about the DS2A Isolated Voltage Stimulator, or any of our stimulators, you can get in touch with our experienced, knowledgeable team.
DS2A Product Information
Application Note 1
Using two DS2A Isolated Constant Voltage Stimulators in series allows stimulation through the same electrodes with different pulse types.
Application Note 2
Using a DG2A Train/Delay Generator and two DS2A Isolated Constant Voltage Stimulators to produce a repetitive biphasic constant voltage stimulus.
Publications which cite use of the Digitimer DS2A can be found on Google Scholar.
The unit can be triggered fast enough to allow >99% “on” time, but the “off” time must >20 microseconds – so, very fast!
The DS2A does not have medical device directive (MDD) certification and has not been designed for safe human use. We offer a range of MDD compliant stimulators for human/patient connection.
Yes and no. The DS2A features an external “gate” input allowing externally derived trigger pulses to define stimulus duration. However, the output amplitude is always determined by the front panel setting of the stimulator. We recommend our NeuroLog system to those interested in using a computer generated waveform to define stimulus timing/polarity and strength.
Yes, there are two simple methods.
(i) The DS2A has the ability to be gated by an external pulse i.e. when external control of pulse duration is selected the output stimulus timing will be controlled by the trigger-in stimulus pulse. It should be noted that (with a 5V input pulse) there is only a very short delay of <2µs for the turn-on and <6µs for the turn-off. When a typical TTL pulse is used, which will only be about 3V, these are matched at 4µs each.
(ii) Alternatively, if a trigger pulse is not available or exact timing is not crucial (for instance when lesioning or injecting dye, there is a jumper which can be set to allow the unit to deliver a current for the duration the single shot button is held down. The internal “Single” jumper determines the output delivered when the “SINGLE” button is pressed (when “EXTERNAL” Duration is selected).
“MON” (factory setting) produces a very short pulse ~10µs when pressed.
“CONT” produces an active output for the duration of the press. This could be useful in dye marking etc.
The visible difference between the two units (apart from the colour!) is that the output control of the DS2A is defined in Volts while the output of the DS3 is defined in Amps. The actual stimulus passing through your preparation is measured in Amps in both cases and is dependent upon Ohms Law (V = IR). If your preparation has a variable impedance (R) and you are using a constant voltage (V) source such as the DS2A, then the actual current (I) passing through the tissue may vary considerably between each stimulus, which may not be a good idea if you want to apply reproducible stimuli. With the DS3, the constant current circuitry prevents variations in tissue impedance from altering the size of current applied (within the 90V compliance limit of the unit), leading to the stimulator equivalent of WYSIWYG – “What You Set Is What You Get”. Unfortunately there are no well defined rules governing the circumstances under which either stimulator should be used. If you are not sure and feel the need to evaluate either or both please contact us.
No, Digitimer no longer offers this service. Since the introduction of the new DS3 constant current stimulator, this unit is now offered to customers requiring a constant current version of the DS2A.
Yes, this is quite simple to setup and has been summarized in an application note available in the downloads section.
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