Pre-Amplifier Headstage, Patient Connection Unit

The differential preamplifier is a small (135mm x 185mm x 45mm) box containing touch-proof connectors for patient electrodes with tri-colour LED indication of electrode impedance. Any combination of channels may be selected to use a Common Reference electrode.

Input impedance of each channel is 100MW

On/off control of individual channels. The electronic inputs of individual channels can be grounded reducing cross-talk noise when recording from fewer channels. This also disconnects the patient from the electronics.

Control enabling the +ve [ref] or -ve [act] input of each channel to be connected to a common Reference input.

The unit is connected to the main unit via a lightweight cable with a plug at the main unit end.

Impedance Checking of individual inputs (not Common). An LED is situated next to each input socket. Pressing the Impedance Check button causes the LED to show one of three colours indicating the impedance of that electrode. The actual value is also passed to the main system for PC display.

The impedance range for each colour is selectable within the software.

The front panel contains three LEDs which are used to indicate the unit’s power supply status and data-bus activity and errors.

Main Amplifier Unit

The main amplifier unit can be bench or rack mounted. It contains the 8 channels of amplification and filtering as well the PC interface circuitry. Each channel output has a BNC socket located on the front panel for connection to acquisition devices. These outputs are duplicated on rear panel mounted 9-pin D type connectors providing a convenient method for connection to multi-channel acquisition hardware. The functional parameters of each channel can be individually set on the PC which is connected to the amplifier via a low-noise serial interface. A second interface connector is fitted to the rear panel so that multiple D360’s can be daisy-chained, allowing commands to further D360s from a single software control interface.

8 Channels of amplification, filter and isolation – all parameters are independent.

Overall system GAIN for each channel x100 – x1,000,000 (10mV/V – 1μV/V). Outputs have a ±10V range.

LOW-CUT FILTER settings are variable between 0.05Hz and 255Hz for -3dB and are second order. (The user may compile their own set of values into the list but the program comes with predefined settings of 0.1, 0.2, 0.3, 0.5, 1, 2, 3, 5,10, 20, 30, 50, 100, 200, 250 – Hz).

NOTCH FILTER – factory set at 50 or 60Hz. User has ‘In’ or ‘Out’ control.

HIGH-CUT FILTER settings are variable between 20Hz and 25,500Hz for -3dB and are second order. (The user may compile their own set of values into the list but the program comes with predefined settings of 20, 30, 50, 100, 200, 300, 500,1k, 2k, 3k, 5k, 10k, 20k – Hz). For those requiring highcut frequencies lower than 20Hz, Digitimer offer a special modification which shifts this range from 2Hz to 2,530Hz, please contact us for details.

The front panel contains three LEDs which are used to indicate the units power supply status, Internal-Error and Data-Bus Busy. It also has an isolated connector for the headstage as well as 8 BNC sockets for monitoring the output of each channel (these signals are mirrored on 9-way ‘D’ connectors on the rear panel).

The rear panel contains a mains IEC inlet socket with voltage selection, fuses and mains on/off switch, as well as 9-way “D” connectors, for connecting all channels to an acquisition system and for serial connection to a PC. The unit also has two ‘mini-DIN’ sockets for daisy-chaining further

D360 systems.

The case is 19″ rack mountable but also has retractable legs making it suitable for bench top use. (483 x 300 x 133 mm (W x D x H) plus handles, connectors and feet)

Mains operating voltage between 90 – 250V (selectable) and 50-60Hz.

CE Certified for Human Use

Certified to the EU Medical Devices Directive, the D360 is an 8-channel isolated amplifier specifically designed for human electro-encephalography (EEG), electro-myography (EMG) or evoked potential (EP) studies. The system comprises a main amplifier unit with a remote active headbox and dedicated Microsoft WindowsTM compatible control software.

Daisy Chain Multiple D360 for Greater Channel Number

Multiple D360 amplifier systems can be connected to a single PC allowing multiples of 8 channels to be controlled by one PC system. Electrode

connection is via touch-proof 1.5mm (DIN 42 802) sockets on the headbox and signal output to your chosen acquisition device is possible either

through the eight BNC connectors on the front panel or a pair of “D” connectors at the rear of the main unit.

Software Control Program Runs in the Background During Acquisition

Because the WindowsTM compatible D360 Control Software can run in parallel with your data acquisition program, adjustments to the amplifier settings or tasks such as impedance checking and deblocking can be made while still monitoring data collection.

External TTL Controlled De-block (Optional Feature)

D360 Amplifiers can include an external de-block BNC input, which allows the operator to “gate” the de-block function of the amplifier with a TTL-

high command. This special modification is particularly useful for D360 operators who need the amplifier to detect responses with short

latency responses following a magnetic stimulus.

Digitimer Amplifier D360

Digitimer D360 Product Reference

Digitimer D360 FAQ