Data-Trax2™ w w w. w p i i n c . c o m Data recording and analysis software & Lab-Trax™ data acquisition systems INSTRUCTION MANUAL WARNING: Do not connect the Lab-Trax hardware to your computer until AFTER the software installation is complete.
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Introduction 1 Welcome 1 How to Use This User’s Guide 1 System Requirements 1 Installation 1 Registration and Updates 2 Comments and Suggestions 2 Technical Support 2 Chapter 1: Quick Start 5 Managing Signals 5 Chapter 2: Acquisition 10 The Basics 10 Signal Conditioning 12 Chart Mode 14 Scope Mode 16 Saving Your Data 18 Chapter 3: Display 20 Introduction 20 Main Window Display Considerations 23 Display Considerations in Other Windows 34 Chapter 4: Controls 35 Menus
Chapter 5: Analysis 44 Overview 44 Analyses of the First Kind: Wave-to-Wave Transforms 44 Analyses of the Second Kind: Digested Data 59 Analyses of the Third Kind: Redisplayed Data 67 Analyses of the Fourth Kind: Detected Data Conditions 74 Analysis of the Fifth Kind: Things Not Possible with 1st, 2nd, 3rd, or 4th Kinds of Analyses 79 Chapter 6: Input and Output Stimulator 81 Outputs States 96 Digital Input 98 Events 99 Chapter 7: Using Settings The Settings Menu Chapter 8: Export
Introduction Welcome Thank you for choosing WPI DataTrax2 Data Recording and Analysis Software. Developed over a 5-year period, DataTrax2 software is the result of more than 70 man years of collective experience in data recording. We are confident that this software will make your data recording and analysis easier, and welcome suggestions for improving our products. Please contact us with comments, concerns or suggestions at 800-234-1757 or via email at: support@wpiinc.com.
.. 1 Insert the DataTrax2 installation CD. 2 A welcome screen will appear offering to install Software. 3 Follow the instructions presented by the Install Wizard. The Install Wizard will tell you when the installation is complete and will restart your computer. 4 Once you have completed the installation process, remove the installation CD from the drive, connect and turn on your WPI Hardware.
• Note your computer model. • Note your operating system version. • Note the amount of RAM (Random Access Memory) in your computer. • Note your DataTrax2 Software version number. See the sample customer support form in the appendix of this manual. Following these steps will enable WPI support staff to quickly and efficiently address your issues.
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Chapter 1: Quick Start Start here if you are already familiar with data recording concepts. This chapter contains all you need to know to begin recording data quickly and easily. Managing Signals The management of recorded data is divided into three steps: 1 Recording data onto the computer, 2 Navigating the recorded data to find particular areas of interest, and 3 Outputting the data either in printed or analyzed form. Recording Data Recording data is the most basic of the three steps.
.. • Clicking the Double Display Time button (little mountain) doubles the screen time. Therefore, a 10second, full-screen display becomes a 20-second, full-screen display allowing twice as much data to be displayed on one screen. 2 To manage the vertical display of the data on the y-axis of the window, the DataTrax2 software uses an AutoScale feature.
Channel Mode Clicking on Channel Mode in Raw Data displays the input option available for a given channel. On a computed channel, clicking on Channel Mode allows you to set up an existing function or to change and set up a new function on that channel. The Channel Menu From the channel menu, some of the parameters also controlled in the Preferences dialog pages, can be set. These include Units, Scale and Title.
.. a single vertical line in Figure 1-1 on page 5). 4 The text attached to a mark can be seen at the bottom of the screen, just above the timeline. Text marks can be dragged and dropped anywhere in the record. For example, a mark may denote that a drug was administered at a certain time. Using the mouse, you can click on the text associated with a mark and drag it to the channel to which it corresponds. Scroll Bar Lastly, data can be navigated by using the scroll bar at the bottom of the Main window.
On a given selection of data displayed in the Analysis window, the program can calculate and report the selected parameters. These are displayed across the top of each channel in the channel bar. By selecting the Send To Journal items in the Tools menu (or right-click menu), these values for the selected parameters can be sent to a part of the DataTrax2 program called the Journal. From any of the Channel menus (or right-click) you can add data and titles to the Journal.
.. Chapter 2: Acquisition The Basics Time, Temporal Resolution, Sample Speed, and Aliasing Temporal resolution in digitally recorded data is determined by the sampling rate, also known as sampling speed. To select a suitable sampling rate, you will need some background on the theory and use of analog-to-digital converters (ADC). The ADC in the WPI computer interface takes simple voltage measurements at regular intervals.
connected by a line, a sine wave with a frequency of 0.1Hz is displayed on the screen. Again, the wave displayed on the screen is not a true representation of the real wave because the sampling speed is too slow. So, how fast does the sampling speed need to be to record a reasonable representation of a real waveform? A general rule of thumb is to sample at a rate that is a minimum of five times faster than the fastest frequency of interest in the waveform.
.. 2 Open the Channels page in the Preferences dialog window and set the sampling speed to 1,000 samples per second. Record 10 seconds of data. 3 Next, set the sampling speed to 500 samples/second and record an additional 10 seconds of data. 4 Repeat this procedure for sampling speeds of 200, 100, 50, 20 and 10 samples/second. Display a section of each recording block in the Main window, then switch to the Analysis window. Closely examine the recorded data as displayed in the Analysis window.
For example, consider an ECG, whose total peak to peak amplitude is only 2 mV. The number of steps that can be resolved with an 16 bit ADC is 2mV/0.600uV or a little more than three steps, which is not sensitive enough to see any meaningful changes. If an amplifier is placed between the signal and the analog to digital converter (ADC), the “raw” signal can be amplified by a selected gain. For example, if the gain is 100 times (X100), the 2mV ECG signal becomes a 200mV signal.
.. mains. The end result of using the 50Hz Low Pass filters is the creation of a quieter, more readable ECG. In general, the application of a low pass filter “quiets” the baseline and improves the signal to noise ratio of the recording. On the other hand, High Pass filters PASS frequencies HIGHer than the set frequency. These filters can remove low frequency interference, such as baseline drift or a standing offset voltage, so that the user sees a more stable baseline.
The dialog boxes (Figure 2-2 on page 15) show the options for starting the recording process for both groups of hardware. Figure 2-2: The DataTrax2 Start dialog boxes User Timed The easiest away to start the recording is for the User to manually press the Record button in the upper right hand corner of the DataTrax2 Main window. User is the default setting in DataTrax2. Recording begins when the User presses the Record button, and will continue until one of the Stop conditions is met.
.. a small piece of data prior to the trigger. To enable pretriggering, check the box next to the label Pretrigger (in the Start Mode box on the Channel page of the Preferences dialog window). Enter the amount of pretrigger time needed in the edit box to the right of the Pretrigger label. Stopping Once recording begins, the DataTrax2 programs offers two different ways to halt the recording: User or Timed . Figure 2-3: The Stop dialog boxes.
not show the event that was trying to be captured. So the acquisition of data at the right moment requires a proper trigger. In the Scope mode either of the previously discussed “non-manual” modes, External Trigger or Trigger from Channel, can be used to start the sweep. Acquiring Data in the Scope Mode Scope mode can be enabled from the Channel page in the Preferences dialog window, which is accessible under the Edit menu. Data can be acquired on as many channels as are available.
.. Sweep Length When operating in Scope mode, DataTrax2 takes “snapshots” of data. Each “snapshot” is called a sweep and has a pre-determined length. The sweep length (or Stop Time) is set in the Stop Mode section of the Channel page from the Preferences dialog window. By choosing Timed as the Stop Mode, the sweep length (in seconds) can be entered into the edit box in that section of the page.
2 Acquisition 19
.. Chapter 3: Display Introduction From a functional standpoint, the DataTrax2 program is really two programs. It is primarily a data acquisition application, whose main task is to record analog experimental data as data points (with X and Y values) and store these data points on the computer. The second task of the DataTrax2 program is to graphically display the collected data in a way that is understandable to the user.
Each channel has its own set of controls located in a Channel Bar immediately above each channel’s data window (Figure 3-2 on page 21). Y-axis scaling is printed to the left of the data. The Channel Bar contains the Channel Menu, Channel Title, buttons for Y-axis display control (Zoom-In, AutoScale and Zoom-Out), Add Function button and a Value Display area. The Value Display box located to the extreme right on the channel bar will display different values depending on the state of the program.
.. for the position of the cursor is reported in the Clock Area in the upper right hand corner of the Main window. Single Cursor mode is used to determine values and to place marks in the record after recording has stopped. To access 2 Cursor mode, press the 2 Cursor icon (Figure 3-3 on page 21) in the toolbar. In this mode, the Value Display area reports the difference in value between Cursor 1 and Cursor 2. In a similar way, the Clock Area reports the difference in time between the two cursors.
Main Window Display Considerations Recorded data has two important dimensions: length and height. The length is the Time axis and the height is the Amplitude. Each of these has its own set of controls Managing Display Time The events recorded using DataTrax2 software may occur over varying time frames. For example, recording the discharge curve of a 9-Volt battery could take hours, while recording the QRS complex in a human electrocardiogram might take only a fraction of a second.
.. Figure 3-5: ECG viewed with a long screen time (top) and a short screen time (bottom). In the second example (Figure 3-6 on page 24), a one hour battery discharge curve is shown in two views. The 2-second screen time shows almost a straight line, but clicking Double Display Time eight times reveals the entire curve. The Display Time parameter, with its two controls, effectively handles the time display. Figure 3-6: Voltage drop of 9-Volt battery viewed with short (top) and long (bottom) screen times.
Managing Amplitude Display The vertical display of your signal is managed in a number of ways. In each channel toolbar (Figure 3-7 on page 25), there are three icons. They represent the Zoom-In (x2), AutoScale and Zoom-Out (x2) features. Clicking and dragging the waveform can be used to offset the recorded wave up or down. In addition there is a Scale menu available from either the Channel menu or by clicking on the values in the Y-Axis on the left hand side of each channel.
.. Rate function could be used on Channels 9-16 to calculate the heart rate of each animal from its recorded blood pressure on Channels 1-8. As with any multi-channel display, the more channels displayed means there is less space that can be given to each channel. In the case of a 16channel Main window display, it is hard to resolve detail in the trace of recorded data in each channel.
Note: Any changes to the default view, will also be made to the preferences and vice-versa. Channel Sizing Figure 3-8: The height of the data displays for four channels in the Main window as set by the default setting (top), and after the handle for Channel 1 was slid down (bottom). In addition to scaling the height of the signal to fit in a given channel area, the amount of display area allotted to each channel in the Main window can be controlled by clicking and dragging on the top of the channel bar.
.. Figure 3-9: Data file of weights hung from a transducer and the units conversion dialog window that sets volts to grams. Once recording is complete, proceed to the 2 Cursor mode in the Main window. (See the Cursors section of this chapter.) The Units Conversion dialog window cannot be entered without being in 2 Cursor mode. Position Cursor 1 over one of the known values, and Cursor 2 over the other known value. Figure 3-10: The Units Conversion dialog window showing the 2-point calibration boxes.
Cursors 1 and 2. Enter the corresponding values in real units into the two value boxes on the right. In the Name area, enter the name of the unit to be displayed on the Y-axis. If a unit name is not entered, Volts will be used as a default name. Figure 3-11: The Units Conversion dialog window showing slope and offset boxes. It is also possible to set the slope and offset directly, if those values are known (Figure 3-11 on page 29). For example, if a pressure transducer produces 5mV (0.
.. Units can also be set from the Channel page of the Preferences dialog window. Each channel can be set with the conversion factors provided by the transducer manufacturer (see the section on Preferences in this manual). All of the recorded data, acquired by the hardware as raw data, are displayed as voltages. From time-to-time, it may be desirable to turn off the Units Conversion and simply view the raw data. To view raw data, open the Units Conversion dialog window (Figure 3-10 on page 28).
Preset Marks If you know the marks that you will be adding to the record prior to recording, you can store the mark text as preset marks. To create a preset mark, type in the mark text in the Mark window, and choose the Add to Mark Presets option by clicking on the down arrow next to the Mark button. This will save the typed text as a preset mark, which can be called by clicking on the Mark drop-down box and choosing the desired preset mark.
.. Navigating By Marks Marks that are placed on the recording can serve as “sign posts,” indicating where important sections of data are located. Click on the down arrow next to the Mark button and choose the mark you want to “go-to.” DataTrax2 software will find the data point associated with that mark and display that section of data in the Main window. In this manner, the user can move between important areas of an experiment without hunting or scrolling for the areas of interest.
3 Wait one minute, type “Test 2" and strike the Return or Enter key. 4 Click Stop. Scroll through the data using the scroll bar on the bottom of the Main window until you locate “Test 1” in the Text Display area. 5 Click on the down arrow next to the Mark button and choose “Test 2". Notice that the record in the Main window has moved to the “Test 2" mark. 6 Using the mouse, click and hold on the comment “Test 2" at the bottom of the screen.
.. Figure 3-15: Online XY Display Considerations in Other Windows Data is only recorded in the Main window. However, other windows can receive selected data from the Main window for closer examination or display in another format, like an XY plot or FFT. There are several viewing options available in these other windows that are not available in the Main window. The actual discussion of analytical functions found in these windows is deferred to the Analysis chapter later in this manual.
Chapter 4: Controls Menus File The DataTrax2 software supports all of the elements found in a standard File menu: Figure 4-1: The DataTrax2 File menu. New: Opens a new file. Only one acquisition window may be open at a time. This function is also available from the toolbar. Open: Opens a previously recorded file and is also available from the toolbar. Save: Saves data to the file currently open and is also available from the toolbar. Save As: Saves data to a new file with a different name or format.
.. Edit The DataTrax2 software supports elements found in a standard Edit menu: Figure 4-2: The Edit menu. Undo: Un-does the last command (Journal Only). Redo: Re-does the last command (Journal Only). Cut: Cuts the selection (Journal Only). Copy: Copies the window in the foreground or selection in the journal to the clipboard for pasting. Also available from the toolbar. Paste: Pastes the contents of the clipboard to the Journal (Journal Only).
OnlineXY: Displays realtime XY plot to the right of the Main window channels. Main Window: Brings the Main window to the foreground. Also available from the DataTrax2 toolbar. Analysis: Brings the Analysis window to the foreground. Also available from the DataTrax2 toolbar. XY View: Brings the XY View window to the foreground. Also available from the DataTrax2 toolbar. FFT (Spectrum): Brings the FFT window to the foreground. Also available from the DataTrax2 toolbar.
.. DownSample: Used to downsample the data. This reduces the information in the file and should be used with caution. Warning: This cannot be undone! Settings The Settings menu lets you load and edit files containing preset recording and analysis parameters. Selecting a file from the list programs DataTrax2 to record data in a specified manner. Settings files have been preprogrammed for each DataTrax2 experiment and specific settings are associated with each lab exercise. Figure 4-5: The Settings menu.
Check for Updates: Checks the DataTrax2.com website for the latest version of the software. You need to be connected to the internet. Toolbars Main Toolbar Figure 4-7: The toolbar in the DataTrax2 Main window. New File: Opens a new file. Only one acquisition window may be open at a time. Open File: Opens a previously recorded file. Save File: Saves data to the file currently open. Main Window: Brings the Main window to the foreground. Analysis: Brings the Analysis window to the foreground.
.. Clicking on the down arrow next to the view name, brings up the View control menu. You can switch the current view from this menu, create a new view from the default view, duplicate the current view, rename the current view, edit the current view, which brings up a View page of the Preferences dialog, or delete the current view. Sequences: The Output Sequence Toolbar is a drop-down list containing sequences of analog or digital outputs defined in the Sequence page of the Preferences dialog window.
•Apply All: Applies the changes and fires all stimulators. As with Apply, on hardware that supports it, the change will happen at the next “best time.” •Stop All: Stops all stimulators. •Apply Now: Forces the stimulator to apply the changes as soon as possible. •Apply All Now: Forces all the stimulators to apply the changes as soon as possible. Constant Mode Figure 4-9: The Stimulator Pulse toollbar in the DataTrax2 Main window. Amplitude: Amplitude of the stimulus in Volts.
.. Apply: Applies any changes to the stimulus protocol made through the Stimulator Toolbar. Clicking Apply while recording will send a stimulus pulse from the output. Refer to the Pulse mode for additional information. Dialog Windows Preferences There are six pages in the Preferences dialog box. Figure 4-12: The pages of the Preferences dialog window. Channels Page The preferences that can be set for all channels include: Figure 4-13: The Channels page of the Preferences dialog window.
Units: Used to convert two raw data values to two corresponding calculated values, using a linear scale. For more information refer to the Units Conversion section Color: Sets the color of the channel. Stimulator Page Used to setup the Stimulator(s) on the WPI 214/118. There are five modes: Off, Pulses, Trains, Constant and Step. The available parameters in each of these modes can be preset and made part of a settings file.
.. Chapter 5: Analysis Overview Today’s analog to digital converters make acquiring data very easy. The challenge to all users is to extract meaning from the mountains of recorded data in order to generate conclusions, reports, and Nobel Prizes. This process is called analysis. Built into the DataTrax2 data recording software is a powerful array of data analysis tools.
Note: Deleting the raw data channel will cause the function channel to have invalid data. Periodic Periodic functions operate on cyclic data to produce a graphical representation of how the Rate, Frequency, Period, Cycle Maximum, Cycle Minimum, Cycle Mean, or RMS (Root Mean Square) vary with time. The program calculates these parameters with each cycle of the signal and displays the calculation on the screen.
.. Exercise To see Threshold and Tolerance in use, record some pulse data using the Tutorial setting from one of the Settings groups. Apply the Rate function to the pulse channel. The Rate function must be able to ignore the second small wave associated with each larger pulse wave; otherwise, it will report a rate that is twice what it should be.
Negative: Only the negative data points are included in the calculation. Data points with values above zero make the Integral larger, those with values less than zero make the Integral smaller. To successfully complete the calculation of the Integral, the location of the zero-line needs to be known. Setting the baseline of the raw data channel to zero is the more important of the two requirements since this function defines the difference between positive and negative areas of the recording.
.. Figure 5-3: Integral with Zero The Reset control in the Integral Setup dialog window determines when the Integral or running count will reset itself to zero. This option allows the Integral to reset itself after a preset time. This is a useful option if the data being integrated contains artifacts that move the Integral artificially up or down. The Reset function keeps the Integral trace in the field of view.
Also enter this X value in the text box below the graph. Clicking the Calibrate Difference between Cursors button will calculate the required calibration value and place it in the Spirometer Calibration window. To account for offset in the spirometer, choose a time at the beginning of the record when there is no flow through the spirometer and enter this value in the Use First N Seconds as Zero text box.
.. unclosed parentheses or division by zero. Since division by zero is a possible occurrence even in legitimate expressions, but it cannot be calculated by a computer, the program substitutes the last calculated value for the quotient if division by zero is attempted. Activating Channel Math To apply the Channel Math function to a channel, click on the Add Function button in the Channel bar. Select Channel Math from the Function menu. Select the channels corresponding to A, B, C and D.
Notice that the filter is subject to the Nyquist limitation of frequency. The maximum frequency in the Filter Setup dialog is exactly half of the sample frequency. Smoothing All experimental data includes noise to varying degrees. Noise can obscure important features like peaks, valleys, or peak widths. DataTrax2 allows you to smooth noisy signals to reveal significant features of your data. In addition to filters, DataTrax2 also offers the ability to smooth the data.
.. known as a Power Number. In addition to specifying the range of frequencies transformed, the frequency resolution can be selected. The higher the frequency resolution, the more data points required to compute the FFT. Therefore, at slow sampling rates, higher frequency resolutions may require the processing of more data points from longer recording periods. Cardiac The Cardiac functions are specifically used for the analysis of electrocardiograms (ECG).
In this function, a preset frequency band is available for each component of the EEG: Alpha, Beta, Theta, Delta, Betalow, Beta Mid and Beta High. For each selected band, DataTrax2 can also calculate the average power in the band and display the value against time. These are beneficial functions to use when teaching students, because they can clearly see the effect that behavior has on components of the EEG.
.. Digital Input The Digital Input function treats the data on the selected channel as a binary number. The functions in the Digital Input submenu are: Raw: The digital value as a 32 bit word is displayed Frequency: The program takes the period in seconds and divides this value into 1. The result is a frequency, which is expressed in Hz or cycles per second. Period: The program takes the period for each cycle. Time On: The time that the selected channels are high.
CrossTime Channel Calculation Initial Delay: The amount of time from the start of recording until the function is initiated. Selection Duration: Period of the protocol. To setup CrosstimeChannelCalculation, you need to setup the Initial Delay before the function is initiated and set the Selection Duration to the period of the protocol. Selection can be set to start when the data on a selected channel goes above an operator selected value.
.. MultiPoint Calibration 5 Analysis MultiPoint Calibration can be used to perform a linear and non-linear calibration of sensors, transducers, amplifiers and other equipment. It can also be used to check if an existing sensor is linear.
Template Match Template Matching is a technique in digital signal processing for finding small parts of a signal which match a template. The idea of template matching is to create a model of a signal of interest (the template, or kernel) and then to search over the recorded data for objects that match the template. To create a template, select a region of interest using the two cursors. Click Create Template from data between cursors to create a baseline for the template.
.. Auto Correlation Correlation is the mutual relationship between two or more random variables (Ali). AutoCorrelation is the correlation of a signal with itself (Parr 1999). AutoCorrelation is a mathematical tool used frequently in signal processing for analyzing functions or series of values, such as time domain signals. Informally, it is a measure of how well a signal matches a time-shifted version of itself, as a function of the amount of time shift.
Analyses of the Second Kind: Digested Data The functions in this kind of analysis take a group of data points selected by the user and "digests" them into a single value. These values can be saved to the Journal within DataTrax2 or exported to other programs. This kind of analysis can proceed in the Analysis window. There are currently 24 functions available in the DataTrax2 program to do this kind of analysis. Some of the functions are: Mean, Max, or Max-Min.
.. Figure 5-7: The DataTrax2 Analysis window. Analysis Window Components Functions List Tiled or Stacked Display 5 Analysis The functions selected in the Add Functions list determine the calculations performed on the data points between the two cursors in the Analysis window. The results of the selected calculations are displayed in the Channel bar area at the top of the each Channel . By default, the channels selected for display are presented in Tiled mode.
Channel Menu in the Analysis Window Clicking on the Channel Menu button or right-clicking in the display area of the Analysis window brings up the Channel menu. Add Ch. Data to Journal: Adds data from the selected channel to the Journal. Add All Data to Journal: Adds data from all channels to the Journal. Add Title to Journal: Adds the function titles to the Journal. Calculations: Brings up the calculations submenu, for performing dedicated calculations in Spirometry, ECG, Blood Pressure and Peak Analysis.
.. V2-V1: Value2-Value 1, i.e. the difference in value between the cursors T2-T1: Time2-Time1, i.e. the difference in time between the cursors Max: Maximum value between the cursors Min: Minimum value between the cursors Mean: Mean or Average value between the cursors. Max-Min: Difference between the maximum and minimum values between the cursors.
Spirometry TV: Tidal Volume IRV: Inspiratory Reserve Volume ERV: Expiratory Reserve Volume FEV1: Forced Expiratory Volume in one second. How much air can be exhaled in the first second of expiration FEV3: Forced Expiratory Volume in three seconds. How much air can be exhaled in the first three seconds of expiration VC: Vital Capacity PEF: Peak Expiratory Flow PIF: Peak Inspiratory Flow TFR:Tidal Flow Rate.
.. ECG Time at R: Time at the peak of the R-wave. PR Interval: The time from the beginning of the P wave to the peak of the R wave. P Duration: Time from the beginning to the end of the P-wave. QRS Duration: Time from the beginning of the Q wave to the end of the S wave. QT Interval: Time from the beginning of the Q wave to the end of the T wave. ST Segment: Time from the end of the S wave to the beginning of the T wave. T Duration: Time from the beginning to the end of the T wave.
Blood Pressure LVEDP pressure: Left Ventricular End Diastolic Pressure Time at LVEDP: Time at LVEDP Max Pressure: Maximum of the pressure, also the systolic value Time at Max: Time at maximum pressure Min.
.. Cycle Duration: Time between LVEDPs Relaxation Index: (Minimum Slope) / (Pressure at Minimum Slope) Tau (Mirsky): Time for pressure to drop to half its value from the value at minimum slope Peak Analysis Max: Maximum amplitude Min: Minimum amplitude Max-Min: Maximum amplitude - Minimum amplitude Mid Amp.
Trailing Slope: Average slope of the signal as it travels from the upper threshold to the lower threshold Max Slope: Maximum slope Min Slope: Minimum slope T @Max Slope: Time at maximum slope T @Min Slope: Time at minimum slope Copy, Export, To copy the view of data displayed in the Analysis window, use the Copy command in the Edit menu. The image can be pasted into any program (including the Journal) that supports the and Print clipboard.
.. XY View Window Components Selecting Channels To plot an XY graph, select the X-axis channel from the drop-down box in the top most plot. Then select the Y-axis channel from the drop-down box in the second plot. If required you can also select a marker channel, to highlight certain points of interest. Once the channels are selected, the XY plot will be displayed. All the data visible in the X and Y axis plots will be included in the XY plot.
Table Functions These functions are available in the XY window. General Y1: Value of Y-Axis Channel at Cursor 1. Y2: Value of Y-Axis Channel at Cursor 2. X1: Value of X-Axis Channel at Cursor 1. X2: Value of X-Axis Channel at Cursor 2. Y2-Y1: The difference in value of Y-Axis channel between the cursors. X2-X1: The difference in value of X-Axis channel between the cursors. MaxY: Maximum value of Y-Axis channel between the cursors. MinY: Minimum value of Y-Axis channel between the cursors.
.. Channel Menu in the XY Window Clicking on the Channel Menu button or right-clicking in the display area brings up the Channel menu. Add Ch. Data to Journal: Adds data from the selected channel to the Journal. Add Title to Journal: Adds the function titles to the Journal. Invert: Inverts the channel data. Copy Graph: Copies the channel graph to the clipboard. This can be then pasted into the Journal or any other program.
the maximum frequency that could be recorded reliably would be 500Hz. If a recording was made at 100 samples per second, the maximum frequency that could be recorded reliably would be 50Hz. When a FFT is performed on data recorded with DataTrax2, the program sets the X-axis to a scale from 0Hz (DC) to a frequency that is a half of the sampling rate.
.. Figure 5-8:FFT Window Display Channel Located in the upper left of the channel display area, this drop-down box allows the user to select the channel to be used in the FFT plot. FFT Functions List The calculations to be performed on the region of the FFT plot between the 2 Cursors are selected from the Add Functions button on the top left of the FFT display area. The results of the selected calculations are displayed in the Calculated Value Display area at the top of the FFT window.
Table Functions These functions are available in the FFT window.
.. Analyses of the Fourth Kind: Detected Data Conditions DataTrax2 software can be used to identify Regions Of Interest (ROI) in recorded data. The identified data points can be sent to either the Journal or the Marks window, where they can be used to either build a report or be exported. While identifying data does not constitute an analysis per se, the detection of specific data always precedes analysis.
• Copying values and their headings to the Journal via the Add Title to Jrnl and Add Data to Jrnl functions in the Right-Click menu of the Analysis window. Auto Find Dialog Window The Auto Find dialog window (Figure 5-10 on page 75) is like the Find window. It is also accessible from the Tools menu and works only from the Analysis or ScopeView window. However, the Auto Find function can be programmed to find multiple data points with the same parameters within a data selection.
.. After the number of repetitions specified or the specified end of the Auto Find routine is reached, the Auto Find routine can be saved by clicking Save on the dialog window. The named Auto Find routines are saved as .iwxfind files and can be called by clicking on the Load button in the dialog window. Specific Events The detection of Specific events within a recording requires the use of an algorithm to find the point or region of interest (ROI).
Figure 5-11: ECG AutoMark Dialog Figure 5-12: ECG AutoMark Example 5 Analysis 77
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Peak Analysis Analysis of the Fifth Kind: Things Not Possible with 1st, 2nd, 3rd, or 4th Kinds of Analyses Not Yet Implemented in DataTrax2: It is impossible to include all of the possible analyses and plotting capabilities required for biological research in a single program. We provide, what we believe to be, useful tools for completing the most common kinds of analyses. For circumstances where the built-in analysis tools fall short of the user’s requirements, DataTrax2 has a Script function.
.. For example, we have created a script in Python, which operates on the R-R intervals of the ECG, which are detected by an Auto Mark function in the Tools menu. Then the R-R script computes and displays a tachogram, plots Delta R-R histograms and determines values for statistics, such as mean, mode, and standard deviation. Writing Scripts DataTrax2 has a special folder called Scripts located in the DataTrax2 folder.
Chapter 6: Input and Output Stimulator The Stimulator page in the Preferences dialog box controls the Digital-to-Analog Converter or DAC of the WPI hardware. It can be reached by selecting Preferences from the Edit menu. The stimulator feature sends the DAC output to the outside world. Using controls described below, output protocols can be built from “square wave” components that are listed on the Simulator page of the Preferences dialog window.
.. Pulse Protocols Figure 6-1: The parameter boxes on the Stimulator page of the Preferences dialog window. In order to understand how protocols are created, it is necessary to define the terms used on the Stimulator page of the Preferences dialog window: Delay: This is the time between the beginning of the recording, at the clicking of the Record button, and the first pulse. Delay is adjustable as follows: WPI 118 (6500 ms), WPI Latrax 24 series:(600 ms, 6s or 60 s).
Holding Potential: This is a voltage between ±10V that can be programmed to shift the resting voltage of an excitable tissue (like a nerve). It is also known as a holding voltage because it can be used to hyperpolarize the membrane potential of an excitable tissue and prevent it from depolarizing or “firing.” Building Output Protocols in Pulse Mode To record stimulus pulses like the examples that follow, the stimulator output of an WPI unit can be connected to one of its own BNC inputs.
.. Holding Potential 0V These settings will create a protocol that delivers continuous square waves with 1V amplitude and 100Hz frequency. 4 Press the Record button. The DAC will wait 100 milliseconds (the Delay value entered) and begin to deliver 5ms pulses at the rate of 100 pulses per second. Each pulse will be 1V high. These pulse parameters can be adjusted in any way with one exception, the pulse width cannot be longer than the inverse of the frequency (or the period).
Figure 6-4: The parameter boxes on the Stimulator page for Train mode. The terms used on the Stimulator page of the Preferences dialog window for configuring trains of pulses, include: Delay: This is the time between the beginning of the recording, at the clicking of the Record button and the first pulse. Delay is adjustable as follows: WPI 214 (650ms), WPI 118 (6500 ms), WPI 3xx:(600 ms, 6s or 60 s) Amplitude: This is the height or voltage of the pulse or wave being generated.
.. Holding Potential: This is a voltage between ±10V that can be programmed to shift the resting voltage of an excitable tissue (like a nerve). It is also known as a holding voltage because it can be used to hyper polarize the membrane potential of an excitable tissue and prevent it from depolarizing or “firing.” Building Output Protocols in Train Mode Connect the stimulus outputs to one of its own BNC inputs as described in the Building Output Protocols in Pulse Mode section of this chapter.
Figure 6-5: Burst of pulses separated by Inter Train Durations. Constant Voltage Protocol Selecting the Constant (voltage) option on the Stimulator page of the Preferences dialog window disables the entry boxes for all stimulus parameters except Amplitude and Delay. When the Record button is clicked, the voltage set on the Stimulator page is delivered to the low voltage output of the WPI unit. The voltage output terminates when the recording is stopped.
.. If the user knows the voltage increment needed at each step, the equation can be transposed to solve for the Number of Steps required in the protocol and this value can be entered on the Stimulator page: (Start Amplitude - End Amplitude) = Number of Steps.
6 To create a step protocol where the voltage returns to a baseline value between steps, alter the Time Off to a number greater than zero. The resulting wave would be similar to that seen in Figure 6-8 on page 89. Figure 6-8: An example of a step protocol punctuated by returns to baseline between steps. 7 A Constant voltage protocol can be combined with the Step protocol to have the voltage return to a different baseline after the completion of the step sequence.
.. Delay Amplitude: The amplitude during the delay period.
Holding potential: The amplitude during the interprotocol duration. Should be set to Start Amplitude if not being used The Stimulator Panel Selecting the Stimulator Panel item in the View menu (Figure 6-11 on page 91) will place a Stimulator Control Panel (Figure 6-12 on page 91) on the Main window. The Stimulator Panel can be used to create a new protocol or change the parameters for an existing protocol Each stimulator mode has a unique toolbar as shown below. Figure 6-11: The View menu.
.. Step Mode Figure 6-14: The Stimulator Step Control Panel. A1: Starting Amplitude A2: Stopping Amplitude. #steps: Number of Steps W(ms): Width of the step in milliseconds (ms) F(Hz): Frequency of stimulation in Hertz (Hz) #R: Repeat Count IP Dur: Inter protocol duration HP: Holding Potential Apply: Applies any changes to the stimulus protocol made through the Stimulator Toolbar.
Rise time: The time taken to go from the Start Amplitude to the Stop Amplitude # Triangles: Number of Triangles IR: Time between Triangles HP: Holding potential Apply: Applies any changes to the stimulus protocol made through the Stimulator Toolbar. Clicking Apply while recording will send a stimulus pulse from the output Note: The Stimulator preferences dialog will draw whatever protocol you specify.
.. Figure 6-18: Channels page of the Preferences dialog window set for testing an Output Sequence. Stimulator Page Figure 6-19: Stimulator page of the Preferences dialog window set for testing an Output Sequence.
On the Stimulator page, select Pulses as the stimulating mode and set the parameters. • Toolbar Steps Freq (Hz) = 1; Amp (V) = 0.05; Time (ms) = 0.1. • Initial Parameters Delay 5 ms Amplitude 0.25 V Number of Pulses 1 Pulse Width 0.1 s Time Off 0.1 s Holding Voltage 0V Sequence Page Figure 6-20: Output sequences page of the Preferences dialog window. 1 On the Sequences page, add a CAPRecruit sequence to the list of current sequences.
.. 5 Return to the Main window; select the CAPRecruit sequence from Sequences control on the toolbar. 6 Click the Record button. The program records, displays and saves the ten progressively larger stimulus pulses on ten successive Scope sweeps. 7 Click on the Analysis icon in the toolbar to view the sweeps recorded for each stimulus amplitude. Outputs States States Output states are used in the construction of sequences.
Figure 6-21: Output States Sequences Digital states can be grouped together in Sequences. A Sequence allows timed execution of digital states. Creating Sequences To create a Sequence, type the name of the sequence in the Edit box next to the Current Sequence Label and click New. Editing a Sequence Select the sequence to be edited in the Current Sequence drop-down box.
.. Firing a Sequence The Sequence Control on the Main toolbar is a menu containing sequences of analog or digital outputs defined in the Sequence page of the Preferences dialog window. Clicking the Sequence button will fire the output sequence selected from the list. Selecting a new sequence in the list also automatically fires that sequence. Digital Input The Digital Input function treats the data on the selected channel as a binary number.
Events As DataTrax2 acquires data, it is aware of the value of each data point as it happens. It should then be possible to "train" the software to watch for values above or below a specified level and have DataTrax2 advise the user when such conditions are met. This feature in DataTrax2 is called an Event. Events are set up in the events page of the Preferences menu. Figure 6-22: Controls for the Event programming There are two types of events: Channel events and Timed Events.
.. Timed Events Event Priority Timed events are triggered after a certain amount of time has passed. Timed events can be repeated, set N = 0 for continuos. Events have priority. Sequences launched by events inherit the priority from that Event. A higher priority event can stop a lower priority sequence, but a lower priority event cannot stop a higher priority sequence. User Events (i.e. sequences triggered by user) are also treated as events having a priority of 50.
Chapter 7: Using Settings The Settings Menu DataTrax2 offers users several choices for recording and displaying data. When certain choices are used repeatedly, a template known as a settings file, can be created to reduce the time required to program the recording software and the A/D converter. To understand how to use settings files, two terms need to be defined: settings group and settings file. A settings group is actually a simple text document that can contain links to individual settings files.
.. Creating a New Settings File The first step in creating a settings group is to create a settings file. Configure the DataTrax2 program to do the experiment you want to do. For example, go to the Channels page in the Preferences dialog window and select the number of channels needed, their titles and any Functions that are needed to display or interpret the data. You can also assign an aim and a difficulty level to each settings file by using the Document Properties command under the File Menu.
Categories Settings files can be organized into categories within a group. To create a new category in the settings group, click on the Add Category button and name the category. You can add settings files from the list of available settings to any category or root category. Settings added to the root category are listed in the Settings menu below the other categories.
.. Chapter 8: Export Printing Once you have recorded and analyzed your data, you’ll probably want to create a report or other presentation. This can be done in a variety of ways, the easiest of which is to simply print the recorded data. The DataTrax2 software uses a WYSIWYG (What You See Is What You Get) printing scheme. That is, the Print command will print the forward window exactly as it appears.
Figure 8-1: Text and image as displayed in the Journal window. Exporting Data Data can be exported from DataTrax2 as either numbers or pictures from any window. To export data, select Export from the File menu and choose the file’s format, location and name in the dialog window. Exporting Pictures The current display can be exported as a picture in bitmap (.bmp) format or in a portable network graphics (.png) format. Portable Network Graphics is a high resolution format for images.
.. If data is exported from the Analysis or ScopeView windows, then only the data displayed in the window is exported. Data from the Analysis or ScopeView windows can be saved in Text (.txt), Matlab (.mat), Axon Text Format (.atf), or DADiSP (.dat) format.
A Add Data to Journal 37 aliasing 10 Amplitude 23 Analysis 7 Area 73 Power 51 Analysis window 8, 37, 39, 104 ASCII 8 Auto Find 37 Auto Mark 37 Autocorrelation 58 AutoScale 6, 25 Axon 8 Events 99 Export 67 exporting data 8 printing 8, 104 saving and saving as 104 External Trigger 17 B bitmap 8 Blood Pressure 65 G Gain Telegraph 44, 53 Grid 37 C Calculated channels 9, 44 Cardiac 9, 52 Cardiac Angle 52 Channel Math 9 Channels 36 Chart 17 Copy 8 CrossTime Channel Calculation 55 cursors 21 behavior of 22 mod
Multiple Sweeps 17 Multipoint 56 N National Instruments hardware 27 Navigating Data 7 O oscilloscope 16 P Paste 8 Peak Analysis 66 Period 7, 45 png 8 Power 7, 9 Preferences dialog 9, 81, 82, 83, 85, 86, 87, 88, 93 Preferred Scale 25 PreTrigger 15 Pretriggering 15 Print 8 pulse protocols amplitude 82, 85 delay 82, 85 pulse 82, 85 pulse frequency 82, 85 train 85 train duration 85 R Rate 9, 10, 11, 45 Recording 5 recording data 1, 5, 30 Registering your software 2 Reset Channel Size 37 Reset Marks 32 Resolutio
