Digitimer Ltd - DS8R Operator’s Manual
Version 2.0
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Digitimer Ltd.
Copyright ©2019
Two pulse modes enable stimulation using either monophasic or biphasic pulses. Additionally, when
in biphasic mode the operator is able to adjust the amplitude ratio of the stimulus and recovery
phases, thereby producing an asymmetric biphasic charge balanced stimulus. Stimulation protocols
can involve repetitive monophasic stimulation lasting tens of minutes or hours resulting in
unpleasant side effects for the subject, such as skin irritation or sensitivity. By applying biphasic
stimuli in a charge-balanced manner, the DS8R may prevent polarisation of the stimulus site,
reducing skin irritation and improving the comfort of the subject. The DS8R also features a polarity
reversal control, which allows the operator to set the unit to deliver positive, negative or alternating
polarity pulses.
The DS8R is not a medical device, does not have any medical device certification and is not suitable
for treatment or diagnostic use. However, it has been designed for safe use in human research
applications and meets all of the following standards.
60601-1 General requirements for basic safety and essential performance.
60601-1-2 General requirements for basic safety and essential performance -
Collateral Standard: Electromagnetic disturbances – Requirements and Tests.
60601-1-6 General requirements for basic safety and essential performance -
Collateral standard: Usability.
60601-2-10 Particular requirements for the basic safety and essential performance
of nerve and muscle stimulators.
62304 Medical Device Software - Software Life Cycle Processes.
14971 Application of Risk Management to Medical Devices.
All our devices are manufactured within our quality system, which is externally audited to ISO 13485
for medical devices. Additionally, each device is subjected to both high voltage isolation tests and
electrical safety tests, during production.
Precautions and Warnings
Operator’s Manual
Carefully study this Operator’s Manual before using the DS8R Bipolar Constant Current Stimulator.
Indications for Use
The Digitimer DS8R is an electrical stimulator intended to be used to apply a stimulus to a human
subject via surface electrodes. It can be used to elicit a response from peripheral nerve fibres or
muscle during research studies of human physiology, psychology and neuroscience.
Risks to Subject Safety
Stimulating electrodes should not be placed thoracically or trans-thoracically as this may increase
the risk of cardiac fibrillation. Care should be taken when selecting appropriate stimulating
electrodes. If the current density of the chosen electrode is greater than 2mA rms/cm2 then the
operator should pay extra attention to stimulus parameters to ensure that the patient does not
suffer burns at the stimulation site.
The DS8R is not suitable for use in close proximity to extreme magnetic fields, such as those
generated by MRI scanners and is not classified as defibrillator proof.
