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caltester:caltester_mode_overview [2024/08/01 15:34] – [CalTester Background] wikisysopcaltester:caltester_mode_overview [2025/03/31 17:22] (current) – wikisysop
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 The functionality is **now available in Visual3D when a CalTester license key is provided**. There is also a stand-alone version of Visual3D that ONLY supports the CalTester, and these options now replace the older software. Users of the old software should have access to the new software automatically when they log into our web downloads page. The functionality is **now available in Visual3D when a CalTester license key is provided**. There is also a stand-alone version of Visual3D that ONLY supports the CalTester, and these options now replace the older software. Users of the old software should have access to the new software automatically when they log into our web downloads page.
  
-**UPDATE:** The standalone CalTester-Plus software application has been discontinued and replaced with a newer CalTester stand-alone application. The new application is simply the CalTester tab in Visual3D all by itself.+**UPDATE:** The standalone CalTester-Plus software application has been discontinued and replaced with a newer CalTester module, which is simply the CalTester tab in Visual3D.
  
 As a reminder, always go to the CalTester tab first, before opening any CalTester related data files. As a reminder, always go to the CalTester tab first, before opening any CalTester related data files.
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 Accurate and reliable kinematics and kinetics data are essential to the appropriate application of movement analysis data for clinical and research purposes. Proper laboratory calibration includes the accurate determination of the positions of the force platform(s) and cameras in the laboratory coordinate system, as well as correct setting of [[Visual3D:Documentation:Pipeline:Force_Commands:Modify_Force_Platform_Parameters|force platform parameters]]. Any errors in the parameter settings or calibration measurements will lead to incorrect values of kinetic calculations that rely on the force data. Accurate and reliable kinematics and kinetics data are essential to the appropriate application of movement analysis data for clinical and research purposes. Proper laboratory calibration includes the accurate determination of the positions of the force platform(s) and cameras in the laboratory coordinate system, as well as correct setting of [[Visual3D:Documentation:Pipeline:Force_Commands:Modify_Force_Platform_Parameters|force platform parameters]]. Any errors in the parameter settings or calibration measurements will lead to incorrect values of kinetic calculations that rely on the force data.
  
-{{:CalTesterFigureSmall.jpg}} {{:CalTesterResults.gif}}+{{:CalTesterFigureSmall.jpg?250px}} {{:CalTesterResults.gif?250px}}
  
 CalTester is an essential tool for laboratories that: CalTester is an essential tool for laboratories that:
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 ==== The design of the MTD2 device allows a force to be applied to the surface of the force platform without any applied moment.==== ==== The design of the MTD2 device allows a force to be applied to the surface of the force platform without any applied moment.====
                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          
-The [[CalTester:Documentation:MTD3|MTD-2 rod]] is a rigid, machined rod with a conical (pointed) tip at each end is used together with a handle and a test plate, each with machined conical depressions. Five tracking targets are attached to the testing rod using rigid posts. Data are sampled simultaneously from the force platform (FP) and the cameras, as forces are applied through the rod to the force platform. The Mechanical Testing Device (MTD-2) is manufactured and supported by [[http://www.motion-labs.com/|Motion Lab Systems, Inc.]] The MTD-2 is a precision-machined calibration-testing tool that can be assembled in less than a minute to create a calibration-testing object suitable for a number of 3D biomechanics laboratory tests. (NOTE: There is an MTD-3 rod that supports adding a load cell on it, and the rods are the same size and work equally well. The MTD-3 may replace the MTD-2.)\\ \\ The following graphics are from the [[https://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\ \\ {{:Fig1CalTesterArticle.png}}\\ \\ {{:Fig2CalTesterArticle.png}}  +The [[CalTester:Documentation:MTD3|MTD-2 rod]] is a rigid, machined rod with a conical (pointed) tip at each end is used together with a handle and a test plate, each with machined conical depressions. Five tracking targets are attached to the testing rod using rigid posts. Data are sampled simultaneously from the force platform (FP) and the cameras, as forces are applied through the rod to the force platform. The Mechanical Testing Device (MTD-2) is manufactured and supported by [[https://mocapmarkers.myshopify.com/|Sisco Mocap]] The MTD-2 is a precision-machined calibration-testing tool that can be assembled in less than a minute to create a calibration-testing object suitable for a number of 3D biomechanics laboratory tests. (NOTE: There is an MTD-3 rod that supports adding a load cell on it, and the rods are the same size and work equally well. The MTD-3 may replace the MTD-2.)\\ \\ The following graphics are from the [[https://www.has-motion.com/download/CalTester/CalTesterArticle2003.pdf|CalTester Paper]] Holden JP, Selbie WS, Stanhope SJ, "A proposed test to support the clinical movement analysis laboratory".\\ \\ {{:Fig1CalTesterArticle.png}}\\ \\ {{:Fig2CalTesterArticle.png}}  
  
 Within the CalTester mode there are two classes of functionality: Within the CalTester mode there are two classes of functionality:
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 ====Section I : Calculating the rod orientation variable under the assumed condition of static equilibrium====  ====Section I : Calculating the rod orientation variable under the assumed condition of static equilibrium==== 
  
-Free-body diagram of testing device: Fp, ground reaction force; Fg, gravitational force (weight); Fa, applied force; r, position vector between tips (p to a) of testing device rod:\\ {{:Calc1CalTesterPlusArticle.png}}\\ Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ {{:CalTesterPlus_DeltaTheta.jpg}}\\ \\ The rod orientation variable ( {{:DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ \\ **Section II : Equation for evaluating the static equilibrium assumption**\\ \\ Under 2D dynamic conditions, the following holds:\\ {{:CalTesterPlus_Eq4_v2.jpg}}\\ \\ Rewriting the left-hand side of Eq. (4)\\ {{:CalTesterPlus_Eq5_v2.jpg}}\\ \\ Rearranging Eq. (5), the magnitude of the angular displacement ( {{:Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ \\ {{:CalTesterPlus_Eq6_v2.jpg}}\\ \\ where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{:ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame.\\ \\ CalTesterPlus does not calculate {{:Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed.  |+Free-body diagram of testing device: Fp, ground reaction force; Fg, gravitational force (weight); Fa, applied force; r, position vector between tips (p to a) of testing device rod:\\ {{:Calc1CalTesterPlusArticle.png}}\\ Thus, r and A are parallel and the test device rod orientation (r) is defined entirely by the vector quantity A that is derived from FP measurements (Fp) and the physical characteristics of the testing device (Fg/2, i.e.the weight of the rod and its center of mass location; in this case, half the rod length).\\ {{:CalTesterPlus_DeltaTheta.jpg}}\\ \\ The rod orientation variable ( {{:DeltaTheta.jpg}}) is determined from the dot product of the unit vector along A and the unit vector aligned with the long axis of the rod (r) as determined using the motion capture components.\\ \\ **Section II : Equation for evaluating the static equilibrium assumption**\\ \\ Under 2D dynamic conditions, the following holds:\\ {{:CalTesterPlus_Eq4_v2.jpg}}\\ \\ Rewriting the left-hand side of Eq. (4)\\ {{:20140107212337caltesterplus_eq5_v2.jpg}}\\ \\ Rearranging Eq. (5), the magnitude of the angular displacement ( {{:Beta.jpg}} ) between vectors r and A due exclusively to the inertial terms can be isolated:\\ \\ {{:CalTesterPlus_Eq6_v2.jpg}}\\ \\ where r is the length of the testing device rod, Icg the moment of inertia of the test device rod about the center of mass location, m the mass of the testing device rod and {{:ThetaDoubleDot.jpg}} is the angular acceleration of the testing device rod relative to an inertial reference frame.\\ \\ CalTesterPlus does not calculate {{:Beta.jpg}} since it operates under the assumption that there is no angular acceleration. For this reason it is important to move the CalTester rod slowly at a constant speed.  |
  
      **Estimate the position and orientation of a force platform, instrumented treadmill, or instrumented stair that minimizes these errors..**                                                                                                                                                                                                                                                                                                 **Estimate the position and orientation of a force platform, instrumented treadmill, or instrumented stair that minimizes these errors..**                                                                                                                                                                                                                                                                                           
caltester/caltester_mode_overview.1722526472.txt.gz · Last modified: 2024/08/01 15:34 by wikisysop