Operator's Manual
DS7A - Constant Current Stimulator
Equipment Description
This manual is to be used as a reference for operators of the
Digitimer
DS7A Stimulator.
The Digitimer Stimulator model DS7A provides constant current high voltage pulses of brief duration for
percutaneous stimulation during investigation of the electrical activity of nerve and muscle tissue. The
output current is continuously variable over the range 0 to 100 milliamps, from a source voltage
continuously variable from less than 100 volts to 400 volts, to meet the requirements of human pathological
cases. Short pulse durations have been made available to minimise any discomfort to the subject. The
pulse duration range can be varied from 50 microseconds to 2 milliseconds in six steps. The DS7A now
incorporates a stimulus polarity control which allows the operator to select between normal, reverse and
alternating polarity modes. A specially designed isolated output stage maintains a square (current) pulse
shape while minimising stimulus artefacts.
The DS7A is mounted in a non-conductive, flame retardant, free standing case and is mains powered.
For higher voltages the Digitimer Stimulator model D185 is suggested.
The stimulator accepts an external electrical trigger pulse input and triggers on the factory set edge at
approxi2.6 Volts. 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 at the rear
panel - this can be factory set to have a positive or negative active state.
Regulatory Statements
EN 60601-1:2006 + A1:2013 Classifications
This equipment is CLASS I with TYPE BF Applied Parts.
This equipment is NOT sealed against any ingress of water and is therefore IPX0.
This equipment is NOT intended to be used sterile. If it is necessary to remove contamination from the
surface of the equipment, an alcohol moistened cloth may be used. Sterilisation of any electrodes should be
performed according to the recommendations from their manufacturer.
This equipment must NOT be used in the presence of flammable anaesthetic gases.
This equipment is rated for CONTINUOUS operation.
Environmental
This unit does not produce any waste.
As with all electronic devices, at the end of its life it should be disposed of by a registered waste contractor
who is made aware of its nature.
Cleaning, Maintenance & Servicing
If the stimulator requires cleaning, it should be unplugged from the mains power supply and wiped with a
damp cloth.
This equipment does not require any regular maintenance but Digitimer recommends that the DS7A is
returned to the factory for inspection and re-testing every 2 years. Please contact us for a reference number
Digitimer Ltd.
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Copyright © 2014
File Ref: N:\Docs\Company\Manuals\DS7A\Issue-14\DS7A-iss14.odt
Last Revised: February 1, 2017
