Stimulus Isolator

Overview:

The FE180 Stimulus Isolator uses the analog output from the PowerLab to produce isolated constant-current pulses. The unit is capable of providing isolation and pulse width from 10 µs to 2.56 ms with a maximum current of 10 mA. Supplied with black and red shrouded plugs and certified power supply.  The unit provides adjustable pulse amplitude, width, and frequency. The Stimulus Isolator is electronically isolated for subject safety, and approved to the stringent IEC 60601-1 BF (body protection) standard. Please visit our website for more details of our safety standards.

A certified Stimulus Isolator is also available in the Dual Bio Amp/Stimulator, allowing the researcher to stimulate and measure biopotenials using the one unit. The FE180 Stimulus Isolator is supplied with a set of shrouded plugs (one RED, one BLACK) for customizing one's own stimulating electrodes. Suitable stimulating electrodes are also available from ADInstruments (purchased separately), which include:

• MLA265 Stimulator Rod with Cable
• MLA260 Stimulator Cable (4 mm shrouded to Alligator clip, 50 cm)
• MLA260/L Stimulator Cable (4 mm shrouded to Alligator clip, 2m)
• MLADDF30 Stimulating Bar Electrode

Features:

• A high-voltage constant-current source that can produce pulses of variable duration and amplitude under software control.
• Current source that can deliver pulses up to 10 mA at 100 V compliance levels; its amplitude is set by a digital attenuator network, which is in turn controlled by the I²C logic.
• High-isolation optical couplers that produce the output to the subject.
• Safety approved power pack External AC wall Transformer (plug pack) coupled through a custom isolation transformer (from which the isolated low voltage and 100 V supplies are derived) provides power to the unit. The power pack complies with medical safety requirements.
• A small internal beeper that can be enabled to give an audible beep with every pulse delivered.

Applications:

The FE180 Stimulus Isolator is suitable for both transcutaneous human nerve stimulation and stimulation of isolated nerves when obtaining evoked response measurements. Applicable to measurements in vivo and in vitro. This unit is ideal for use in student experiments involving nerve and muscle stimulation for evoked response measurement.

Specifications:

Output

• Connection type: 2 × 4 mm (0.16") shrouded banana plugs
• Output configuration: Constant-current stimulator with hardware limited repetition rate, with following discharge clamp
• Output waveform: Rectangular, monophasic pulses with software-set pulse amplitude and duration
• Safety: Approved to IEC601-1 BF (body protection) standard
• Isolation rating: 4000 V AC_rms for 1 minute
• Safety indicators: A single multi-colour indicator displays the isolated
• stimulator status. A green flash indicates delivery of a valid stimulus. A yellow flash indicates an out-of compliance condition
• Safety switch: Isolating on-off switch flicks down to disconnect quickly
• Compliance voltage: 100 V fixed
• Current ranges: 100 μA, 1 mA, or 10 mA full scale
• Current rise time: <1 μsec (1 kΩ load @ 10 mA) 25 μsec (100 kΩ load@ 0.5 mA)
• Current fall time: <1 μsec (1 kΩ load @ 10 mA) 25 μsec (100 kΩ load @ 0.5 mA)
• Operating duty cycle: up to 20%
• Resolution: 1% of full scale (1 μA, 10 μA, or 100 μA)
• AC line leakage current: <200 nA p–p
• Differential output noise: <1 μA p–p
• Power source: Non-isolated circuitry supplied by PowerLab via I²C connection Isolated and high-voltage circuitry derives power from the external 12-volt AC, 300 mA_rms, wall-plug transformer. High voltage isolation is provided by an internal isolation transformer. No batteries required.

Pulse Control (internal pulse duration control)

• Pulse duration range: 0.01 ms to 2.56 ms in 0.01 ms steps
• Duration accuracy: ±0.01% +5/-0 μs
• Repetition rate: up to 2000 Hz
• Repetition accuracy: ±0.1% (determined by PowerLab)
• Current rise delay: 12 to 22 μs (variable)

Control Port

• I²C port: Provides control and power.
• Interface communications rate of ~50 Kbits/s.

Physical Configuration

• Dimensions (h × w × d): 55 mm × 120 mm × 260 mm (2.2" × 4.7" × 10.2")
• Weight: 1.3 kg (2 lb 15 oz)
• Operating temperature range: 5 to 35 °C, 0 to 90% humidity (non-condensing)

ADInstruments reserves the right to alter these specifications at any time.