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Digital Stimulator - 8 channel

/images/big691.jpg * Single board computer w/ LCD touch screen
* Scope mode displays waveforms
* 8 banks of 3 timers, synchronous / asynchronous * 8 internal and 8 external trigger inputs
* 32 separate outputs ( 24 BNC's front panel )
Description Digital Performance
The DS8000 represents a quantum leap in the performance of the research stimulator, and is the most advanced stimulator on the market. With a built-in computer, the entire waveform is generated digitally with precision timing. The DS8000 can generate stimulating wave patterns of a complexity unmatched by any other instrument on the market. A built in digital oscilloscope allows the user to preview waveforms on the LCD. An Ethernet connection allows the user to transfer custom waveforms and upgrade the software using TCP/IP protocol via remote access.

Outputs, Inputs, and Waveforms
The DS8000 has 8 analog outputs, 8 TTL outputs and 8 combined analog or TTL outputs. Each combined output can be comprised of a combination of any of 1 to 8 channels. Eight independent internal timers and eight independent external triggers are offered. The built-in waveforms include unipolar, bipolar, and paired pulse, as well as step, sine, ramp and custom. An external trigger, internal analog channel, internal TTL channel, or any of the eight built-in timers can be assigned to control each output channel. A unique feature of the DS8000 is the capability to stimulate with a waveform that is identical or similar to real biopotential wave patterns associated with ECG, EEG or action potentials. A biopotential waveform captured by a data acquisition system may be transferred to an Excel spreadsheet for editing or modification, then loaded into to the DS8000.

Single Board Computer
Although it may be argued that some functions of the DS8000 can be implemented on a standard PC, it is important to recognize that the inherent design of a PC operating system makes the accurate delivery of precision pulse protocols impossible. Despite the fact that PCs are very economical, they are simply not designed to generate highly accurate timing because the microprocessor resources are not prioritized for this function. In addition, analog waveform generation is not readily available without adding expensive output boards and the required programming is non-standard. The DS8000 platform is based on a powerful single board computer that is fully dedicated to the temporal accuracy and precision required in current biological and neurological research. Indeed, the DS8000 Digital Stimulator offers all of these solutions plus Good Laboratory Practices (GLP) compliance for research traceability.

Paired Pulse Protocol
The DS8000’s Paired Pulse function allows the user to generate triggered paired pulses (including refractory period) from a single channel without the use of a train function. WPI’s paired pulse algorithm simplifies the arduous repetitive task normally associated with manual resetting of interpulse intervals in refractory studies. Auto-increment eliminates the need to overlap train functions from multiple channels to generate a complete protocol. Thus, there is a significant reduction in setup time and a minimization of the potential for human error during interactive protocol modification. Fig. 1 shows Channel 1 configured in the TRIGGERED PAIRED PULSE mode. In this example, a dual pulse event occurs synchronously with each trigger pulse from Channel 8, which is set to trigger every 300ms. The initial interpulse interval is set to 20 ms. Subsequent interpulse intervals are automatically incremented by 35 ms for each three consecutive paired pulse events. The resulting paired pulse is displayed in the lower trace on the DS8000 scope. The upper trace shows the master trigger pulse set up on Channel 8.

Soft Keys and GUI Interfacce
The DS8000 employs “soft keys”, which are programmable controls widely used in several menu options to sequentially change the numerical value of any variable waveform parameter. The DS8000’s soft keys are easily recognized as single or double “+” and “-“ signs located adjacent to a parameter value box (Fig.1). Soft keys provide quick and easy access to modify parameter values on the fly during an experiment. The GUI interface (Fig.3) enables the user to assign the incremental value of the soft key to suit the needs of the experiment. Alternatively, a pop-up numeric keypad is accessible for each parameter to program a precise value that is not a multiple of the softkey-preset increment.

Combined Channel Assignments Matrices
The CTTL (COMBINED TTL matrix) and CA (COMBINED ANALOG matrix) screens permit the assignment of any combination of the 8 available TTL or Analog signals to any permutation of the respective (8) CTTL or (8) CA BNC outputs. The setup in Fig. 4 indicates that all TTL channels are assigned to their respective CTTL outputs with the exception of the output of CTTL 1, which is assigned a combination of the TTL signals from channels 4 and 5. Changing assignments is as easy as checking the associated box. The CA tab reveals an identical matrix for programming the COMBINED ANALOG BNC outputs.
Specifications
Timing parameters: Period (total signal width) 0.04 ms to 10,737,418.24 ms
Timing parameters: Pulse width 0.02 ms to 10,737,418.24 ms
Timing parameters: Bipolar gap width 0.00 ms to 10,737,418.24 ms
Timing parameters: Operating Modes Free run, triggered, gated, Train, DC
Timing parameters: Triggers 8 External, manual, TTL 1-8, combined TTL 1-8, timer start or stop
Timing parameters: Train events 1-199
Timing parameters: Train pulse width 0.02 ms to 10,737,418.24 ms (3 hours)
Timing parameters: Train pulse DELAY 0.04 ms to 10,737,418.24 ms
Timing parameters: Train period 0.06 ms to 10,737,418.24 ms
Timing parameters: BNC Output connectors Analog, combined analog, combined digital (TTL )
Timing parameters: Waveforms Unipolar, bipolar, rectangular, sine, ramp, step, paired pulse, custom defined
Timing parameters: Custom waveform 12 steps/ voltage point (1025 if remote controlled)
Timing parameters: VARIABLE step waveform 100 points (1025 if remote controlled)
Timing parameters: Output Noise < 5 mV rms
Timing parameters: Timing Accuracy < 100 ppm
Timing parameters: OUT PUT Voltage Resolution 5 mV
Timing parameters: Max. output voltage +/-10V @ +/- 10 mA @ 0.005 V/step
Timing parameters: Output impedance 50 Ohm Analog, < 1 ohm Combined Analog
Timing parameters: External TRIGGER sync 40 ?s minimum pulse TTL , CMOS
Timing parameters: Digital I/O 5V max 10 mA (input); 25V @ 500 mA (open collector output)
Timing parameters: Mains voltage 85-260 V AC, 45-65 Hz 50W
Timing parameters: Dimensions 13.3 cm x 42.5 cm x 25.4 cm 5.25” x 16.73” (19” rack) x 10”
Timing parameters: SHIPPING Weight 12 lb (5.5 kg)
Timing parameters: Ambient temperature(-10 to +40 °C; -20 to +50 °C (Internal)
Timing parameters: Humidity Max.95% relative humidity, non-condensing
Notes SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE.
Manuals and Resources Instruction Manual DS8000-IM-041006.pdf
References L-H Shi, F.Luo, D.J. Woodward, J.Y. Chang. "Basal ganglia neural responses during behaviorally effective deep brain stimulation of the subthalamic nucleus in rats performing a treadmill locomotion test." Synapse 59. 2006: 445-457.
Ordering Information To place an order for this product, please contact the appropriate WPI office or distributor.

Customers can order direct from our China office:
WPI China
Address: Rm.20A, No.8 Dong Fang Rd, Liang Feng Building, Lu Jia Zui Financial District, Shanghai PRC
Phone:+86 21 68885517
Fax:+86 21 68885537
Code:200120
Accessories DLS100- Digital Linear Stimulus Isolator
Application Notes Application Notes No Application Notes available for this product at this time.
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