Ballistic Measurement System – User Guide

The Ballistic Measurement System is designed as a state-of-the-art testing and training system for rehabilitation and the development of athletic performance. The system consists of both hardware and software:

Hardware

Position Transducer

A position transducer from Celesco (http://www.celesco.com) is used to accurately measure the position of the bar or subject.  A 0-5 volt signal out of the transducer corresponds to 0 to 3 metres of cable extension.  The suggested model is Cable Extension Transducer PT5A-0150-V62-UP-1K-M6.  

Computer Interface

The BMS uses the XPV Interface developed by Fitness Technology (www.fittech.com.au) which was custom developed by Fitness Technologies as a USB (Universal Serial Bus) device for high speed data collection.  Both displacement and force data are collected and transferred to the host computer over the USB port. There are three versions of the XPV interface:

1) XPV6 – which appears as a serial (RS232) device. This is the older model and requires more detailed setup to find the communications (COM) port that has been assigned to the XPV6. Detailed explanation of how to find the COM port is available by clicking here.

Software

The Ballistic Resistance System software has been developed to run on PC compatible computers under Windows XP or Vista.  Please note that the software is not guaranteed to work properly under Windows 95, 98, ME, NT 4.0 or 2000.  This software is used for all measurement, training, brake control, and configuration functions. 

Installation

The software can be downloaded from the Innervations Web site (http://www.innervations.com) or provided on disk.  The latest version will always be available for you to upgrade at any time. If you do not have the required hardware (XPV interface) then the program will run in a demonstration mode, loading sample data previously collected.

Two programs are required to install the full working version of the system:

1.        USB Device Driver

2.        Ballistic Measurement System Software

Click Here for Instructions for Installation of the FTDI Device Driver

 

Instructions for Installation of Ballistic Resistance System Software

CD-ROM Version

The entire Innervations Website is contained on the accompanying CD-ROM.  This includes the latest versions of all our software.  To install the Ballistic Measurement System:

1)         Insert the CD-ROM into your drive.

2)         The AutoRun feature should load your web browser and open the CD-ROM menu.  If this does not occur automatically then:

a.        run your web browser (e.g. Internet Explorer or Netscape)

b.       Select File and then Open and then Click on Browse

c.        Locate the file default.htm on the CD-ROM, click Open and then OK

3)         A menu will be displayed.  Click on Install Ballistic Measurement System

4)         Select Run this program from its current location and Click OK

5)         If the your browser displays a security warning and asks if you want to install and Run “BMSInstall.exe”, Click Yes.

6)         Click OK to extract the Ballistic Measurement System

7)         Click Setup to start the installation.

8)         Follow the installation directions provided on the screen

 

Downloading the Ballistic Measurement System Software

1.        Navigate your web browser to our download page (http://www.innervations.com/ballistic/download.htm)

2.    Follow the instructions to download the Ballistic Measurement System software.

Using the Ballistic Measurement System Software

The program has two modes.

Collect and Analyse

Collects data at the sampling frequency you specify for the number of samples set in the configuration.  The data is then displayed and you can perform various calculations or select peaks, zoom the data etc..  Displacement data will be collected and if the option is selected, force will also be recorded.  This mode is for performance testing that requires data on displacement, velocity, acceleration, force and power output during a given movement. 

Training

Displacement is monitored (optionally force signal if available) and various summary data determined such as minimum and maximum displacement, contact time, velocity, work done and power. Further information is provided in the section on Training.

Main Menu

The software uses a number of windows selectable from the top menu.  The following is an explanation of each of these windows and their functions:

 BMSHel16 Ballistic Measurement System   User Guide 

  

 

File

 

BMSHel17 Ballistic Measurement System   User Guide 

 

File – Description of options

Open – opens an existing data file previously saved on disk.  Sampling frequency, number of samples and whether force has been recorded are also read in with the file.  Data will be displayed and can be filtered or processed to calculate summary data.

 

Close – closes the currently displayed data set.

 

Save – saves the currently displayed data to disk under its existing file name.

 

Save As – saves the currently displayed data to disk under a file name that you specify.

 

Export Data – exports the current data as a text file of the format:

time         displacement         velocity                  acceleration           force       power

 

Exit – exits the program.

Configuration

Selecting this option allows you to determine how the BMS functions e.g. set sample frequency, calibrate the displacement etc. as well a access the InstaCal software and test the card and cable installation.

 BMSHel18 Ballistic Measurement System   User Guide

 

Configuration – Description of options

 

 

 

 

Configuration – Ballistic Measurement System

 

The following figure is a screen capture of the Configuration window for the Ballistic Measurement System.  Select the different option sets by clicking on the tabs.

BMSHel19 Ballistic Measurement System   User Guide 

 This table describes each of the options and settings for configuring the Ballistic Resistance System.

 

Option Range of Settings Description
Number of Samples 100 to 30,000Default 2,000 Number of samples to be collected when the Collect Data button is pressed in the Collect and Analyse window or the Start button is clicked in the training window.
Sampling Frequency 100 to 10,000Default 500 Enter the sampling frequency (Hz) at which you want to record the data for either testing or training. Each channel will be collected at this frequency.
Sampling Duration 0.1 to 300Default 4 Enter the time period (seconds) over which you wish to collect data for testing or training. The number of samples will adjust to provide this time duration at the current sampling frequency.
Feedback Threshold -32,000 to 32,000Default 3.0 Threshold setting for audio feedback of performance during training. Whatever graph (displacement, velocity, power) is displayed then if the result for the current rep exceeds the feedback threshold then a success sound will be emitted.
Repetition Threshold 0 to 32,000Default 0.05 metres Minimum distance bar has to move to be counted as a repetition in the training mode.  This reduces false repetitions being counted.
Force threshold to detect flight 0 – 200Default 10 Newton Used when analysing vertical jumps in which there will be a flight phase. 
Mass 0.5 – 2,000Default 80 kg Enter the mass of the bar being used. If measuring jumping performance then include the subject’s mass as well.
Cutoff Frequency for filtering of displacement data (Hz) 0-200Default 0 Frequency cutoff for the filter used to smooth the displacement data. Setting of 0 disables the filter altogether.
Cutoff Frequency for filtering for velocity data (Hz) 0-200Default 20 Frequency cutoff for the filter used to smooth the displacement data prior to calculation of velocity data. Setting of 0 disables the filter altogether.
Cutoff Frequency for filtering for acceleration data (Hz) 0-200Default 16 Frequency cutoff for the filter used to smooth the displacement data prior to calculation of acceleration data. Setting of 0 disables the filter altogether.
Record Force Yes/NoDefault No Setting to Yes records force and position data simultaneously, and includes both in analysis and calculation.
1 channel – 4 channels Select 1 or 4Default 1 channel Select 1 or 4 channels depending if your force measurement system outputs 1 or 4 z-force channels.
XPV6XPV6+XPV7 Select the appropriate USB interface Three different interface units are available for the BMS. Each will have a label indicating the model. Select the correct model and then clickConnect. The status bar at the bottom of the window should indicate that the interface has been found.
MultiMedia PC Yes/NoDefault No If your computer has a sound card and speakers allowing it to play WAVE files then this sound can be used for the training feedback. Otherwise select No and a normal beep will be used.
Enable Eccentric Strength Test Yes/NoDefault No The EST has been developed to assess eccentric strength.  Selecting this option enables display of 6% and 10% limits to determine of the test has been performed correctly.
Cal. Slope Force -32,000 to 32,000Default 1.0 Enter the calibration slope for the force input. A calibration routine has been included and can be selected by pressing the Calibrate Force button.
Cal. Int. Force -32,000 to 32,000Default 0.0 Enter the calibration intercept for the force input. This value is adjusted each time the button Zero Position is pressed.
Cal. Slope Disp -32,000 to 32,000Default 1.0 Enter the calibration slope for the displacement input. A calibration routine has been included and can be selected by pressing the Calibrate Position button.
Cal. Slope Int. -32,000 to 32,000Default 0.0 Enter the calibration intercept for the displacement input. This value is adjusted each time the button Zero Position is pressed.
Output to Excel check or uncheck to select output to Microsoft ExcelDefault checked Selecting this option will output the summary variables from the process window to an Excel spreadsheet.
Cal. Log File any valid file nameDefault BMSCalibration.log Enter a file name in which to save the results of the position transducer and force calibration. This file name is not usually changed unless a range of transducers is to be used and separate calibration log files for each.
Data Directory any valid directorydefault c:\Program Files\Ballistic Measurement System\Data\ Enter the name of the directory in which to store and retrieve measurement and training data files. Pressing the Data Directory button will allow you to select the directory.
% Braking Level  0 to 100%Default 0% Type in the braking level, then pressApply button.

 

Calibrate Displacement

From the main menu select:

  • Tools
  • Options

The following window will appear.  Click on the Calibration tab.

BMSConfig1 Ballistic Measurement System   User Guide

From the configuration window you can click on the button Calibrate Position and the following window will be displayed.

Procedure:

1)       Position the bar (end of cable) at an arbitrary starting position.  If you are attaching the system to a Smith machine this would be the bar at the bottom of the range of movement.  Click the button labelled Read Bottom Position.  The software will read the current AD value and display it in the text box.

2)       Position the bar (end of cable) at an arbitrary end position.  If you are attaching the system to a Smith machine this would be the bar at the top of the range of movement.  Click the button labelled Read Top Position.  The software will read the current AD value and display it in the text box.

3)       Enter the distance in metres between the top and bottom positions. Measure this as accurately as possible using a tape measure.

4)       The new calibration factor will be displayed.

5)       To view a log of past calibration factors click on View Calibration Log.

6)       Click on Done when you are satisfied with the calibration.

BMSHel20 Ballistic Measurement System   User Guide


How often should I calibrate the Displacement?

The displacement transducer is very stable in its output relative to the cable extension. As such you should not have to calibrate very frequently. The best option is to calibrate the system a number of times over several days and get an idea of the amount of drift in the calibration factor. It should not be that large.  For scientific testing we recommend calibrating the displacement prior to every test session.  For routine athlete testing or the training mode, once every week or two should be sufficient.

Calibrate Force

From the main menu select:

  • Tools
  • Options

The following window will appear.  Click on the Calibration tab.

BMSConfig1 Ballistic Measurement System   User Guide

Click on the button labelled Calibrate Force.  The following window will appear.

BMSHel21 Ballistic Measurement System   User Guide

1)       For convenience it is recommended to accurately weighing two people, convert their masses to weight force in Newton by multiplying by 9.81.  Place a known weight force in Newtons on the forceplate (one of the weighed people).  Click the button labelled Read Force A The software will read the current AD value and display it in the text box.  Enter the weight force inNewtons of the person on the forceplate.

2)       Instruct the second person to stand on the forceplate with the first.  Click the button labelled Read Force B The software will read the current AD value and display it in the text box labelled Enter Force A.

3)       Enter the weight force in Newtons of the two people combined in the text box labelled Enter Force B.

4)       The new calibration factor will be displayed.

5)       To view a log of past calibration factors click on View Calibration Log.

6)       Click on Done when you are satisfied with the calibration. Note that either load A or B can be repeated if you wish and in either order.

How often should I calibrate the Force?

Force platforms are generally very stable. As such you should not have to calibrate very frequently. The best option is to calibrate the system a number of times over several days and get an idea of the amount of drift in the calibration factor. It should not be that large.  For scientific testing we recommend calibrating the force prior to every test session.  For routine athlete testing or the training mode, once every week or two should be sufficient.

 

Collect and Analyse

Selecting this menu option opens the following window:

 BMSHel23 Ballistic Measurement System   User Guide

Procedure to Collect Data

1)       Instruct the subject to get in position ready for the start.

2)       Click on Zero Position – this is an arbitrary position above which displacement will be positive and below which it will be negative.  It is necessary to set this only if values such as maximum and minimum height are important to your analysis e.g. jump height.  For vertical jump, the zero is best set for the subject standing erect on the tips of the toes.  This will give the best indication of height jumped above this take-off point.

3)       Instruct the subject to perform the test movement and Click Collect Data.  The data collection period will depend on the frequency and number of samples selected in the configuration.

4)       On completion of data collection, the displacement data will be smoothed and displayed.

5)       Click on Velocity, Acceleration, Force, or Power to select other data sets to display.

Calculation of Data Sets

Immediately after data collection is completed for a given trial, the following calculations occur:

  1. Calculation of displacement, velocity and acceleration data – displacement data is filtered (smoothed) at the selected cutoff frequencies using a fourth order Butterworth digital filter. Individual cutoff frequencies can be selected to filter the displacement data prior to calculation of velocity and acceleration data. That is, on the configuration screen under the “Filter Settings” tab independent filter cutoffs can be set for displacement, velocity and acceleration. These should be set to produce a smooth though representative signal for each of the data sets, displacement, velocity and acceleration. These settings are independent in that the raw (unfiltered) displacement data is first copied then filtered at the displacement filter cutoff to produce the filtered displacement data. The same process is repeated, filtering the raw displacement data at the velocity filter cutoff, then differentiated using the finite difference technique to produce the velocity data. For acceleration, the raw displacement data is filtered at the acceleration filter cutoff, and then differentiated twice using the finite difference technique to produce acceleration data.
  2. Calculation of force and power data – This process varies depending if force data is measured directly or must be calculated from the acceleration data and mass used. If the force is not measured directly from a force plate other suitable transducer, force time data is calculated by multiplying the acceleration data calculated in step 1 by the mass that has been manually entered into the program. Power is then calculated by multiplying this force data by the velocity data calculated in step 1. If the force is measured directly then power is calculated by multiplying the measured force data by the velocity calculated in step 1.

Procedure to Set Start and End Points

Two cursors are provided on the graph that you can select and place where in the time period of data collection.  Point 2 must always be set after point 1.  Select which point to set by clicking on the option box and then double-click on the graph to insert the cursor.  Cursors can be moved by clicking on the left and right arrow buttons.  Clicking zoom displays only the data between the cursors.

 

When the cursors are set on the graph, summary data of Maximum, Minimum, and Average are displayed next to the graph.

 

The cursors are also used to set the data range that is to be analysed when the Process Button is clicked.

Process

BMSHel24 Ballistic Measurement System   User Guide
Clicking this button generates summary data for the region marked by the two cursors on the graph. Following is a description of these variables.

 

Results of Data Analysis

The results window displays a number of important biomechanical variables which are useful for assessing performance.  All of the variables are calculated for the time period enclosed by the two cursors on the graph.  The following table summarises these variables:

 

Variable Definition
Peak Force highest force value recorded ( Newtons ).
Mean Force average of the forces recorded ( Newtons )
Peak Power highest instantaneous power output recorded ( Watts ).
Mean Power average power output recorded ( Watts ).
Peak Velocity highest velocity value recorded (m.s-1)
Minimum Velocity lowest velocity value recorded (m.s-1). Usually and indication of velocity during the eccentric phase.
Maximum Displacement maximum displacement recorded (metres)
Minimum Displacement minimum displacement recorded (metres)
Maximum RFD highest increase in force recorded over a 30ms time period (N.s-1)
Time to Peak Force time to attain the peak in force (seconds)

 

Save

Clicking the Save button will write the summary results to a Microsoft Excel spreadsheet if this option is selected and your computer system has the software installed.

 

1.        File name

2.        Maximum displacement

3.        Minimum displacement

4.        Peak velocity

5.        Minimum velocity

6.        Peak Force

7.        Mean Force

8.        Peak Power

9.        Mean Power

10.     Maximum Rate of Force Development (30ms epoch)

11.     Time to Peak Force

 

Training

The training system monitors the repetitions, distances, velocities, power, contact/concentric time, and work done during training.  In addition, a threshold level of performance can be set through the configuration window, and audio feedback provided as to success or failure.

 BMSHel25 Ballistic Measurement System   User GuideRecording a Training Set

1)       Click New Set to clear any existing data recorded.

2)       If the movement has a flight phase e.g. vertical jump, jump squats, bench throws i.e any movement in which the person leaves the ground or the bar is projected into the air; then click on the Flight Phase option so that it is checked.  If the movement does not have a flight phase e.g. bench press, traditional squat, push-press, power clean, or any of the Olympic-style lifts then click on the Flight Phase option so that it is NOT checked.

3)       Instruct the subject to assume the starting position and when ready press the Zero Position button.

4)       It is crucial to set an accurate zero position when Flight Phase is checked because this position is used to determine the start and end of each repetition as well as height thrown or jumped and contact time.  For throws this is usually the arms extended position and for squat jumps the standing erect on the tips of the toes position. 

5)       If the movement does not have a flight phase, then set the zero at the bottom of the movement.  For example, when testing and training Olympic lifting movements then set the zero when the bar is resting on the ground.  For a squat or bench press, set the zero at the bottom of the movement.  The zero point is not as crucial for movements that do not involve a flight phase.

6)       Click Start to start recording the data and the subject should begin the set of exercises.

7)       Data collection will stop after the number of samples selected in Configuration have been recorded.  To record for more or less time, adjust the sample duration setting in the Configuration Window.

 

Print

Clicking this button prints the training set data on the default Windows printer.

 

Save

Clicking this button saves the training set data to the selected filename.  This is a text file which then be opened using Word, Excel, Notepad etc..

 
Data to Plot

Click on the option button for the data that you want displayed during or at the completion of a set of exercises.  The graph data will change to reflect your selection.

 

Maximum Height - The peak height attained during the repetition measured in metres.

 

Minimum Height - The minimum height attained during the repetition measured in metres.

 

Contact Time - When Flight Phase is checked the contact time is the time from landing (pass zero on way down) through the bottom of the dip to take-off (pass zero on way up). Measured in milliseconds.  If Flight Phase is not checked then the time is Concentric Time. That is, the time of the concentric phase, measured from the bottom of the movement to the top. Measured in milliseconds.

 

Peak Velocity - The maximum velocity achieved during a given repetition. Measured in metres per second.

 

Power - The average power output during a given repetition. Calculated as the work done (mass x 9.81 x displacement) divided by the time of the concentric movement.  The displacement is calculated as the distance between the bottom and top of the upwards movement.  Concentric movement time is calculated as the time from the bottom of the movement (change from eccentric to concentric) to the zero point if flight phase is selected or the top of the movement if flight phase is unchecked. 

Tools

 BMSHel26 Ballistic Measurement System   User Guide

  

View Analog Inputs

Selecting this option displays a window with all 8 input channels displayed. The value is the actual AD reading and will be an integer between 0 and 4095 (for 12 bit AD cards).

 BMSHel27 Ballistic Measurement System   User Guide

 

 

The purpose of this tools is to view the input channels to assist in fault finding and to check connections.

 

 

Scale and Offset

BMSHel28 Ballistic Measurement System   User Guide   

This tool allows you to adjust the displacement and/or force data by scaling it or applying an offset value.  Scaling simply multiplies the data set by the value entered.  Offset adds the value entered to the data set. To subtract a value from all data in the set enter a negative number.

 

The purpose of this tool is to correct for errors during data collection.  For example, if the system was not calibrated correctly a new scaling factor can be applied to rescale the data.  Or, if the system was not zeroed correctly the data set can be shifted up or down to account for this.

 

 

Test Serial Interface

BMSHel29 Ballistic Measurement System   User Guide 

This tool allows you to send and receive commands and data from the serial position transducer.  This is best for testing the communication with the transducer and also for troubleshooting the serial interface.  Type the command into the text box.  Click the Send Command button, then click Read Response to view the data coming back from the serial transducer.

 

Contacting Fitness Technology

 We welcome your inquiries and feedback. Please do not hesitate to contact us.

 Mailing:

Street: 21 Bishop Street

Suburb: Skye

State: South Australia

Post Code: 5072

Country: Australia

 Telephone:

Australia: 08 8331 9229

Mobile: 0418 815 400

International: +61 8 8331 9229

Facsimile:

Australia: 08 8331 9229

International: +61 8 8331 9229

Web Site:

                http://www.fittech.com.au

Email:

               info@fittech.com.au