DS7RDigitimer

DS7R Constant Current Research Stimulator

Introduction
The DS7R Constant Current Research Stimulator delivers brief duration (50-2000µs) isolated current pulses fortranscutaneous electrical stimulation and activation of nerves and muscles via surface electrodes. The current output of
the DS7R is adjustable over the range 0mA to 999mA, with a compliance voltage variable from less than 100V to 400V.
The pulse duration range can be varied from 50 microseconds to 2 milliseconds in six steps. The DS7R incorporates astimulus 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.

Flexible Stimulus Parameters for Demanding Applications
The DS7R is virtually identical to our medically certified DS7AH stimulator, but has some important differences, whichmake it more suitable for demanding research applications, such as sensory threshold testing, studies of nociception(pain), behavioural psychology, sports medicine or rehabilitation research. Unlike the DS7AH which is limited to amaximum pulse duration of 200µs, the DS7R is able to deliver stimuli of up to 2ms. This means that the DS7R can deliver
pulses of >50mJ, which means it cannot be medically certified to the same standard as the DS7A and DS7AH. Instead it
is offered for research applicaitons involving human subjects or larger animals.

Safe for Human Research Use
Although the DS7R is not a medical device, it has been designed for safe use in human research applications and meetsthe 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.

DS7R
Research Stimulator

DS7R
Stimulus Output
CURRENT selected by 10 turn dial and x1/x10 switch.
Dial reading 00.0 to 99.9 giving 0 to 100 mA (99.9 mA) for x1 setting and 0 to 1000 mA (999 mA) for x10 setting.
PULSE DURATION 50, 100, 200, 500, 1000, 2000 microseconds (µs)
PULSE POLARITY Three position toggle switch selects Normal/Reverse/Alternating.
COMPLIANCE Continuously variable from 100V to 400V.
ON/OFF On is up. Off disables output and open circuits terminals.
CONNECTIONS 4 mm shrouded sockets (red and black) on 3/4" centres. Red socket goes positive with reference toblack socket.

Trigger
The Maximum trigger rate is 1,000 pps (1 kHz).
INPUT Electrical via Rear Panel BNC socket:
Triggers: Logic signal (+3 to 15V) +ve edge, TTL compatible (-ve edge by factory change). Minimum Pulse Duration is 5
microseconds.
Front panel: Push button.
Rear panel: 3.5mm mono jack socket for contact closure foot switch (contact closure).
OUTPUT Rear panel BNC, positive TTL pulse, 1 ms (950 ±50µs) wide (can be factory set for a negative pulse).

Indicators

Dimensions
Size: 255 x 100 x 225 mm (d x h x w).
270 x 110 x 225 mm (d x h x w) - over controls and feet.
Weight: 2.1 kg (approx.).

Other
Power: 100 - 120V or 200 - 240V @ 47-63 Hz. Rating: <30 VA
Case Material UL94 V-0 Flame Retardant. Case Screw: 2.5mm Hex/Allen key compatible.

The Digitimer DS7R is NOT a medical device and use is limited to human/animal research applications

Digitimer Ltd37 Hydeway, Welwyn Garden City, Hertfordshire, AL7 3BE, UK
Tel: +44 (0)1707 328347 Fax: +44 (0)1707 373153
E-mail: sales@digitimer.com
Website: www.digitimer.com
Last updated: 17/05/18

DS7R
Research Stimulator

Digitimer reserves the right to change product specifications without notice.

TRIGGER LED - Amber, flashes for each trigger received.
POLARITY LED – Green, two LEDs indicate the polarity of the next output pulse.
TOO-FAST LED – Amber, Lit when trigger frequency exceeds 100Hz in Alternating Polarity Mode. Results in stimulus
output being disabled and FAULT condition (see below).
OUT OF COMPLIANCE LED - Amber, lit when selected current not delivered.
FAULT LED - Amber, illuminated on (i) sensed over-current internally (ii) over-current to the subject or (iii) Trigger
frequency “Too-fast” in alternating polarity mode. The unit is latched in this condition until reset by the Output On/Offswitch being placed in the OFF position.
POWER ON LED - Green, illuminated for power on