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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 – IsolatorNL822 – Two Channel AC PreamplifierNL844 – Four Channel 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 – Four Channel Low Pass FiltersNL143 – Three Channel Difference AmplifierNL144 – Four Channel 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 ItemsNeuroLog System CasesNL900D NeuroLog System CaseNL905 Compact NeuroLog System Case
Pressure Transducers & AccelerometersPressure TransducersForce TransducersAccelerometersStimulator ModulesNL510 – Pulse BufferNL512 – Biphasic BufferNL800A Constant Current Stimulus IsolatorNeuroLog System Application NotesSignal AmplificationTriggering & Pulse GenerationSignal Conditioning Filtering & ProcessingElectrical Stimulation
Amplifier Accessories D175 Electrode Impedance Meter D179 Performance Checker D360 Audio Interface D360 USB to Serial Adaptor D177 Bio-Feedback Unit Isolated Amplifiers for EMG / EEG D440 2 or 4 Channel Isolated Amplifier D360 8-Channel Patient Amplifier D360R 4 Channel Research Amplifier
Neurodiagnostic AccessoriesIntraoperative Monitoring (IOM) and Electroencephalography (EEG) Electromyography (EMG)Nerve Conduction Study (NCS) Evoked Potential (EP)Axelgaard Stimulation ElectrodesTouch Proof Plugs Adaptors & Electrode Linkers
Peripheral Stimulators DS5 Isolated Bipolar Constant Current Stimulator DS7A & DS7AH HV Constant Current Stimulator NEW DS7R HV Constant Current Research Stimulator NEW DS8R Biphasic Constant Current Stimulator
Stimulator AccessoriesD188 Remote Electrode SelectorElectrode Connection HeadboxesTrigger CablesElectrode HandlesMiscellaneous ItemsTranscranial Cortical StimulatorsD185 MultiPulse Cortical Electrical Stimulator
Cath SecureCATH-SECURE – OriginalCATH-SECURE – ExtendedCATH-SECURE PlusCATH-SECURE – Dual TabCATH-SECURE For KidsNG SECURE
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Urodynamic ConsumablesUrodynamics CathetersPump Infusion SetsTransducer Pressure DomesUrodynamic Consumables Accessories
£3,240.00 – £3,462.00
DS7A & DS7AH HV Current Stimulatorw are suitable as general purpose electrical nerve or muscle stimulators for human stimulation and are medically CE marked in the UK/EU and 510(k) FDA cleared within the USA. The DS7A provides up to 100mA constant current high voltage pulses of brief duration for trans-cutaneous stimulation during investigation of the electrical activity of nerve and muscle tissue. The DS7A is also commonly used in psychology, cognitive neuroscience and pain research applications. The output current is continuously variable over the range 0 to 100mA from a maximum compliance voltage of 400V. For more demanding applications, the DS7AH allows currents up to 1A with a reduced maximum pulse duration limit of 200µs. This model is offered to overcome the difficulties of stimulating deep peripheral nerves, or large muscles such as the quadriceps with large area electrodes. For those who require the high currents of the DS7AH along with the flexibility to use pulses of up to 2ms, we now offer the new DS7R and DS8R research stimulators.
To reduce tissue polarization and in response to customer demand, current models of the DS7A and DS7AH include a three position (+ve, alternating and -ve) polarity control, allowing the user to reverse stimulus polarity or automatically alternate polarity between successive stimuli. The instrument is mounted in a non-conductive, free standing case and is mains powered. The stimulator requires a TTL trigger pulse input and triggers on the positive edge (negative edge can be factory set). Alternatively a foot switch may be connected to a socket on the rear panel or the front panel push button pressed. A TTL compatible trigger output is provided at a BNC socket on the rear panel.
For higher voltages we recommend the D185 MultiPulse Transcranial Cortical Stimulator.
While the DS7A and DS7AH do not permit any external control of the stimulus parameters, anyone interested in this sort of capability should refer to our DS8R Biphasic Research Stimulator, which offers the same output capabilities as the DS7AH, but adds truly biphasic output and multiple options for external control of all pulse parameters.
DS7A & DS7AH Application Notes
DS7A & DS7AH HV Current Stimulator
Publications which cite use of the Digitimer DS7A & DS7AH can be found on Google Scholar.
The maximum output of the DS7A is 100mA while that of the DS7AH is 1A (with reduced output widths). We find that for the majority of applications, the DS7A is perfectly suitable, however, the main exception is where the human quadriceps muscle is being directly stimulated. In this particular case, we would recommend the higher output of the DS7AH.
Of course we do. Digitimer manufactured several devices suitable for this. Certain configurations of the NeuroLog system can be used to generate quite complex trigger pulse protocols compatible with the trigger input of the DS7A/AH. However, our battery powered DG2A Train/Delay Generator complements the DS7A/AH by providing a continuous burst of trigger pulses with control over frequency.
The current production versions of the DS7A/AH stimulators now have the facility to alternate the polarity of the pulses in a burst. With this new feature, the DS7A/AH can produce +ve going, -ve going or alternating polarity pulses through the use of a three position toggle switch.
The DS7A and DS7AH are not supplied with output plugs, however we do provide them as optional accessories. The part code for a pair (one red, one black) is D185-OC1.
Digitimer does now offer a range of Neurodiagnostic accessories to be used with our stimulators and amplifiers. We appreciate that we cannot include all types of electrode, so If you experience difficulty obtaining electrodes of the correct specifications, we would be glad to help.
The DS7A/AH triggers on the +ve edge of a standard TTL compatible logic pulse (+3V to +15V) of at least 5µs duration.
The higher output DS7AH has a limiting feature that for safety reasons prevents use of these wider pulse durations. Although your stimulator has DS7A on the front panel, please check the serial number label on the back of the unit, as I think you will find it indicates that it is a DS7AH.
Yes, it is possible to do this and the method has been summarized in an application note.
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DS7A HV Current Stimulator, DS7AH HV Current Stimulator