Table of Contents
Related Manuals for Plexon Stimulator 2.0
Summary of Contents for Plexon Stimulator 2.0
- Page 1 STIMULATOR 2.0 Plexon Inc 6500 Greenville Ave. Suite 700 Dallas Texas 75206 United States of America Tel: 214-369-4957 Fax: 214-369-1775 E-mail: info@plexon.com www.plexon.com Stimulator 2.0 Stimulator 2.0 April 2011 April 2011...
- Page 2 TURN THE STIMULATOR POWER OFF Plexon Inc Proprietary The information contained herein is the property of Plexon Inc. and it is proprietary and restricted solely to assist Plexon Inc. customers. Neither this document nor the contents may be disclosed, copied, revealed or used in whole or in part for any other purpose without the prior written permission of Plexon Inc.
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Page 3: Table Of Contents
Getting Started..................15 Overview ..............................15 Operational Flowchart ........................... 16 Launching the Stimulator 2.0 software ..................17 Creating a burst of rectangular pulses .................... 18 Verifying the output on an oscilloscope ..................19 Compliance voltage and stimulation failure ................. 22 Automatic electrode discharge ...................... - Page 4 6.15 Options: Digital Output Mode ......................48 Input and Output Connectors ..............50 Power In ............................... 50 Digital In ..............................50 USB 2.0 ................................. 50 Stim Out ............................... 51 Digital Out ..............................51 Current Monitor ............................52 Stimulator 2.0 - 4 -...
- Page 5 Power on/off Transients ........................55 Current Monitor with an Open Circuit .................... 56 Impedance Test with an Open Circuit ..................... 57 Channel fails to start in Impedance Test mode ................57 Specifications ..................58 © Plexon Inc - 5 -...
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Page 6: Introduction
Thank you for purchasing this Plexon product. We hope you are pleased with every aspect of it. Please do not hesitate to contact us if you have any questions. -
Page 7: System Components
Neurotechnology Research Systems System components When you receive your Plexon stimulator, confirm that you have the following pieces: USB memory with software & drivers Plexon 14-20-A-14 AC power cord (7.5 ft)* Volex 17250 10 B1 Power Supply Plexon 09-06-A-14-P1 DC power cable (6 ft) -
Page 8: Installation
Hint: If you do not see the command window at least briefly then it is quite possible that the driver installation did not complete. In this case, double click on CDM20802_Setup.exe a second time. Stimulator 2.0 - 8 -... -
Page 9: Software Installation
If the software is already installed, then the welcome screen gives you the option to repair (re-install) or remove the software as shown on the right above. If the software is not already installed, then the welcome screen shown above on the left appears. Click Next to continue. © Plexon Inc - 9 -... - Page 10 Neurotechnology Research Systems Select the location to install the software: 4.2.4 The default install location for Windows 7 (64 bit) is C:\Program Files (x86)\Plexon Inc\ The default install location for Windows XP is C:\Program Files\Plexon Inc\ Click Next to continue.
- Page 11 Neurotechnology Research Systems Once the progress bar starts moving, the installation completes quickly. 4.2.7 Click Close to complete the software setup. © Plexon Inc - 11 -...
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Page 12: Hardware Installation
You may connect to either OUT 1 or OUT2 on the power supply. Connect the USB cable between the stimulator and the computer. 4.3.4 IMPORTANT: Turn on the stimulator power and launch the stimulator GUI before 4.3.5 connecting the stimulator to any electrodes. Stimulator 2.0 - 12 -... - Page 13 Connect BNC cables between the monitor channel outputs and an oscilloscope. Monitoring 4.3.7 the current and voltage delivered to the electrode is an essential part of stimulation. © Plexon Inc - 13 -...
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Page 14: Turning On The Power For The First Time
“Installing device driver software” to “Your device is ready to use”. In Windows XP, the balloon cycles through several different displays including “Plexon Stimulator”, “USB Composite Device”, and “USB Serial Converter X” where X is successively A, B, C, then D:... -
Page 15: Getting Started
Monitoring the electrodes during stimulation is a critical component of successful stimulation. In addition to performing stimulation, Stimulator 2.0 also has a special impedance testing mode. In impedance testing mode, the stimulation pattern is a predefined 1 kHz ±100 nA sine wave that is automatically loaded into every channel. -
Page 16: Operational Flowchart
First phase amplitude Load File Start and width Interphase Vmon Scaling delay Second phase amplitude Monitor and width Number of Number of pulses pulses Rate Rate Trigger Mode Trigger Mode Load Load Start Start Monitor Monitor Stimulator 2.0 - 16 -... -
Page 17: Launching The Stimulator 2.0 Software
Neurotechnology Research Systems Launching the Stimulator 2.0 software Make sure the stimulator is connected to the computer and turned on. Then launch the Stimulator 2.0 software by double clicking on the desktop icon. You should see the factory default graphical... -
Page 18: Creating A Burst Of Rectangular Pulses
“Load” button at the far the left of the row of controls: Note that the GUI controls for configuring the pulse parameters become grayed out once the channel has been loaded. To change the parameters you must go back to “edit” mode. Stimulator 2.0 - 18 -... -
Page 19: Verifying The Output On An Oscilloscope
−250 mV for 50 µs. Considering the 2.5 mV / µA scaling factor on the current monitor these 250 mV steps represent current steps of 100 µA as expected from our channel configuration settings. The durations also match our settings. © Plexon Inc - 19 -... - Page 20 The change in electrode voltage during the first phase of the pulse is thus given by: The access resistance and capacitance of the model electrodes on the test board are 4.99 k and 4700 pF respectively. Therefore the expected initial voltage jump for a 100 µA current is: Stimulator 2.0 - 20 -...
- Page 21 . Since there is no current during the inter-phase period the voltage also remains CHARGE constant during this period. = 500 mV @ electrode ACCESS = 1.06 V @ electrode CHARGE 50 µs 25 µs 50 µs © Plexon Inc - 21 -...
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Page 22: Compliance Voltage And Stimulation Failure
~600 ~400 1000 µs µs µs Although the amplitude of the first phase still looks okay the duration appears to be too short and the duration of the inter-phase period appears to be too long. Stimulator 2.0 - 22 -... - Page 23 This example clearly illustrates the importance of monitoring the electrode during stimulation. Monitoring the electrode is necessary to verify that the actual output from the stimulator matches the programmed response. © Plexon Inc - 23 -...
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Page 24: Automatic Electrode Discharge
This is easily seen on the voltage monitor as shown in the figure on the right below. Discharged Not discharged V Automatic electrode discharge turned on (default) Automatic electrode discharge turned off Refer to section 6.14, Options: Discharge Mode for additional details. Stimulator 2.0 - 24 -... -
Page 25: Arbitrary Waveforms & Complex Rectangular Pulses
Click the “Load Ch1” button to open a file selection dialog and then select the file “3_pulse_burst_variable.pat”: The text in the button changes from “Load Ch1” to the name of the name of the file selected: A graphical representation of the waveform is displayed: © Plexon Inc - 25 -... - Page 26 Change the “No. of repetitions” to be 2 and the “Rate” to 1000 Hz: Then “Load” and “Start” the channel: The output of the stimulator is: Rate (1000 Hz = 1 ms) One waveform Repeated twice (No. of pulses = 2) Stimulator 2.0 - 26 -...
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Page 27: Impedance Measurement
The controls for all channels become grayed out and a pre-defined arbitrary waveform pattern called “Z-test” that codes for a ±100 nA 1 kHz sinusoidal current is automatically loaded for every channel: Click the start button to begin generating the sinusoidal current on channel 1: © Plexon Inc - 27 -... - Page 28 Now the output of the voltage monitor is a sinusoid with a peak to peak amplitude of ~ 76.8 mV: 76.8 mV Continue to change the resolution of the monitor channel to obtain the largest amplitude sinusoid on the monitor channel that is not clipping. Try 40 /mV 856 mV Stimulator 2.0 - 28 -...
- Page 29 The model electrodes on the test board have a resistance of 4.99 k in series with a 4700 pF capacitor. The expected impedance for this combination at 1 kHz is 34.2 k in agreement with the measurement above. © Plexon Inc - 29 -...
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Page 30: Working With Real Electrodes
Next observe the response of the electrode to the default 100 µA 50 µs stimulation pulse. Current monitor: 250 mV @ V = 100 µA @ electrode 250 mV @ V = 100 µA @ electrode 50 µs 25 µs 50 µs Stimulator 2.0 - 30 -... - Page 31 For example, you can estimate the equivalent capacitance of the electrode from the impedance measurement. The impedance of a capacitor C at a frequency f is given by: © Plexon Inc - 31 -...
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Page 32: Starting Stimulation From A Digital Input
Configure channel 1 using the “3_pulse_burst_variable” arbitrary pattern and set the No. of repetitions to 2 and the Rate to 1000 Hz: Now select the “Rising” Trigger Mode: Download the stimulation parameters to the stimulator by selecting “Load”: Stimulator 2.0 - 32 -... - Page 33 The stimulator is now armed and when the digital input for channel 1 goes high, the stimulation pattern starts and plays to completion: Pattern Pattern Digital input still high at end of 1 pattern © Plexon Inc - 33 -...
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Page 34: Stopping Stimulation
Even though this temporarily results in an unbalanced stimulation, the automatic electrode discharge feature (see section 5.7) prevents long term charge accumulation on the electrode. Refer to section 6.12, ABORT, for some examples. Stimulator 2.0 - 34 -... -
Page 35: Gui Function Reference
Once the stimulation parameters for a channel have been configured, press the load button to download the configuration to the stimulator hardware. Once the stimulation parameters have been downloaded to the stimulator, the channel configuration controls become grayed out. © Plexon Inc - 35 -... -
Page 36: Stimulation Stop/Start
Press the start button to initiate playback of the stimulation pattern for the channel when the trigger mode is set to software. The stimulation parameters for the channel must be loaded before the start button can work. Stimulator 2.0 - 36 -... -
Page 37: Rectangular Pulse Parameters
If the charge delivered in the second phase is not equal and opposite to the charge delivered in the first phase, then a warning will pop up when you attempt to load the stimulation parameters. The net charge imbalance per pulse is also given in the warning. © Plexon Inc - 37 -... -
Page 38: Number Of Repetitions And Pulse Rate
200 µs must be repeated at a rate less than 4878 Hz since 1/(200 µs + 5 µs) ~ 4878 Hz. The rate parameter may be entered in steps of 0.001 ms (1 µs). Stimulator 2.0 - 38 -... -
Page 39: Arbitrary Waveform Patterns
When the stimulation pattern is played back, each current amplitude from the file is played for the fixed amount of time specified by the duration parameter. The fixed sampling rate format is especially useful for coding continuously varying shapes such as the action potential waveform. © Plexon Inc - 39 -... -
Page 40: Variable Sampling Rate
As with rectangular pulses, the arbitrary pattern should be charge balanced, meaning that the same amount of current is deposited and withdrawn from the electrode. The Stim2 software will automatically analyze the loaded file and give a warning if the net charge is not zero. Stimulator 2.0 - 40 -... -
Page 41: Vmon Scaling And Z Conversion
Measure the peak to peak amplitude of the signal on the voltage monitor in millivolts and multiply the reading by the scale factor to obtain the electrode impedance in Ohms: © Plexon Inc - 41 -... -
Page 42: Z Conversion
1 kHz ±100 nA sinusoidal stimulation pattern is automatically selected and loaded for each channel. Start stimulation on a channel and observe the voltage monitor output for that channel to determine the impedance of the electrode. See section 5.9 for an example. Stimulator 2.0 - 42 -... -
Page 43: Trigger Mode
1. Once the stimulation pattern is triggered it will play to completion even if the digital input goes low during the stimulation. If another rising edge occurs during the stimulation pattern it is ignored (e.g. the rising edge marked 2 is ignored). © Plexon Inc - 43 -... -
Page 44: Level Trigger Mode
Press the Individual button to configure the mode of each channel independently of the others. Hint: You probably want to return the Edit/Load control to Individual after pressing Edit All or Load All and there is no reason not to do so. Stimulator 2.0 - 44 -... -
Page 45: Start Mode
Only one channel may be monitored a time. Connect the current and voltage monitor outputs to an oscilloscope using standard BNC cables to see the stimulation pattern that is being applied to the selected electrode. © Plexon Inc - 45 -... -
Page 46: Abort
Pressing abort in the middle of third pulse results in a truncated third pulse and an unbalanced stimulation, but is the fastest way to stop an ongoing stimulation. Abort Pulse in progress does NOT complete Stimulator 2.0 - 46 -... -
Page 47: File Open / File Save
The default values of the rectangular pulse parameters are stored in a read only file called “Factory_Default.stm”. If you open the “Factory_Default.stm” file just after launching the software you will restore the GUI controls to their factory fresh state. © Plexon Inc - 47 -... -
Page 48: Options: Discharge Mode
Digital output mode from the options menu. Digital output mode set to low during inter-pulse interval: Waveform Interpulse Waveform Stimulator 2.0 - 48 -... - Page 49 ANY channel is playing back a stimulation waveform: Digital output 17 with digital output mode set to low during inter-pulse interval: Digital output 17 with digital output mode set to high during inter-pulse interval: © Plexon Inc - 49 -...
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Page 50: Input And Output Connectors
Input and Output Connectors Power In This information is provided for reference only. Use the recommended Plexon power supply and cable to power the stimulator. The power input connector is a standard 9-pin circular mini DIN connector. The stimulator operates from ±5V and ±15V power supplies. -
Page 51: Stim Out
Digital Out Digital outputs 1 – 16 indicate when the corresponding channels are stimulating. Digital output 17 goes high when any channel is stimulating. See section 6.15, Options: Digital Output Mode for additional details. © Plexon Inc - 51 -... -
Page 52: Current Monitor
If the output of the current monitor does not appear to match the stimulation pattern you requested, refer to section 5.5, Verifying the output on an oscilloscope and section 5.6, Compliance voltage and stimulation failure. Stimulator 2.0 - 52 -... -
Page 53: Voltage Monitor
Therefore connecting a BNC cable between the voltage monitor output and an oscilloscope will typically connect the stimulator analog IO ground to the AC wall outlet ground. Stimulation Cable The pinout for the stimulation cable with Plexon PN 14-03-A-03 is provided below for your convenience. © Plexon Inc... -
Page 54: Sample Arbitrary Waveform Pattern Files
These files are based on the same data as their “40k” counterparts described above, but the original 40 kHz spike waveform has been interpolated and up-sampled to 167 kHz. This results in a noticeably smoother waveform on playback. Stimulator 2.0 - 54 -... -
Page 55: Stimulator Limitations
-15V may be applied to all electrodes for ~2 seconds. Allow at least 1 minute between turning the power switch on and off. © Plexon Inc - 55 -... -
Page 56: Current Monitor With An Open Circuit
For example, stimulating with a rectangular pulse pattern when no electrode is connected will result in transients on the current monitor at the beginning and end of each phase of the pulse as shown below. Stimulator 2.0 - 56 -... -
Page 57: Impedance Test With An Open Circuit
© Plexon Inc - 57 -... -
Page 58: Specifications
HCT, Low < 0.33V, High > 3.84V Digital input/output latency < 1 µs Maximum trigger rate 100 kHz Minimum trigger pulse width 1 µs Arbitrary waveforms Maximum sample points 1000 Maximum update rate 1 MHz (1 µs) Stimulator 2.0 - 58 -... - Page 59 Neurotechnology Research Systems © Plexon Inc - 59 -...
- Page 60 Plexon Inc 6500 Greenville Ave. Suite 700 Dallas Texas 75206 United States of America Tel: 214-369-4957 Fax: 214-369-1775 E-mail: info@plexon.com www.plexon.com Stimulator 2.0 April 2011...
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