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visual3d:tutorials:events:gait_events [2024/07/03 17:45] – created sgrangervisual3d:tutorials:events:gait_events [2024/11/29 18:50] (current) – sgranger
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-====== Gait_Events ====== +====== Gait Events ======
- +
-(( Under Development.....)) +
 Gait Events, such as //Heel Strike// and //Toe Off//, are commonly used to identify gait cycles, and normalize signals accordingly. Generally, using force platforms is the most accurate method to automatically identify gait events. However, when force platforms are not available, or due to certain gait pathologies, it is also possible to identify gait events manually. This tutorial describes the different ways to create gait events. Gait Events, such as //Heel Strike// and //Toe Off//, are commonly used to identify gait cycles, and normalize signals accordingly. Generally, using force platforms is the most accurate method to automatically identify gait events. However, when force platforms are not available, or due to certain gait pathologies, it is also possible to identify gait events manually. This tutorial describes the different ways to create gait events.
  
 ===== Gait Event Acronyms ===== ===== Gait Event Acronyms =====
- 
 Definitions of the gait event acronyms used in Visual3D Definitions of the gait event acronyms used in Visual3D
  
 The automatic gait events command and many of the events created in the tutorials, and used in the example files have 3 (or 4) character labels that have been used consistently albeit cryptically. These acronyms are historical and derive from the early versions of software that read C3D files because the original C3D format allowed a maximum of characters for an Event Label. The automatic gait events command and many of the events created in the tutorials, and used in the example files have 3 (or 4) character labels that have been used consistently albeit cryptically. These acronyms are historical and derive from the early versions of software that read C3D files because the original C3D format allowed a maximum of characters for an Event Label.
  
-These Event labels are divided into two categories. The kinematically based categories include: +These Event labels are divided into two categories. The kinematically based categories include: \\ 
 +**RHS** = Right Heel Strike \\ 
 +**RTO** = Right Toe Off \\ 
 +**LHS** = Left Heel Strike \\ 
 +**LTO** = Left Toe Off \\
 \\ \\
- +The kinetically based categories refer to those events that describe contact with a force platforms.\\ 
- +**RON**= Right On \\ 
-**RHS**= Right Heel Strike +**ROFF**= Right Off \\ 
-**RTO**= Right Toe Off +**LON**= Left On \\ 
-**LHS**= Left Heel Strike +**LOFF**= Left Off \\
-**LTO**= Left Toe Off+
 \\ \\
-The kinetically based categories refer to those events that describe contact with a force platforms. 
  
-\\ +All RON events are also RHS events, but RON events are only created when contact is made with a force platform. This provides a means to declare a range of data for reporting only when in contact with the force platform because Joint Moments and Joint Powers for example do not have meaningful data when the foot is in contact with ground but no ground reaction forces are measured.
- +
- +
-**RON**= Right On +
-**ROFF**= Right Off +
-**LON**= Left On +
-**LOFF**= Left Off +
-\\ +
-All RON events are also RHS events, but RON events are only created when contact is made with a force platform. This provides a means to declare a range of data for reporting only when in contact with the force platform because Joint Moments and Joint Powers for example to not have meaningful data when the foot is in contact with ground but no ground reaction forces are measured.+
  
 ===== Using the Ground Reaction Force ===== ===== Using the Ground Reaction Force =====
- 
 If Force Platform data exists, and if Visual3D model segments have been created, Visual3D can detect contact with the force platform and compute the appropriate event labels. If Force Platform data exists, and if Visual3D model segments have been created, Visual3D can detect contact with the force platform and compute the appropriate event labels.
  
   - Open the Command Pipeline   - Open the Command Pipeline
   - Expand the **Event Creation** folder   - Expand the **Event Creation** folder
-  - Double click with the **Left Mouse Button** on the **[[Visual3D:Documentation:Pipeline:Event_Commands:Automatic_Gait_Events|Automatic_Gait_Events]]** command\\ +  - Double click with the **Left Mouse Button** on the **[[Visual3D:Documentation:Pipeline:Event_Commands:Automatic_Gait_Events|Automatic_Gait_Events]]** command \\ {{:tutorial6_7.jpg?850}} \\ 
-{{tutorial6_7.jpg}}\\ +  - Execute the Pipeline 
- +  - Several Events have been created and highlighted on the graphs. \\ {{:tutorial6_9.jpg?850}} \\
-  - Double click with the **Left Mouse Button** on the **Automatic_Gait_Events** command in the processing list box.\\ +
-{{tutorial6_8.jpg}}\\ +
- +
-  - Select the direction of gravity. For this file select **Z** +
-  - Execute the Pipeline\\ +
-{{tutorial6_9.jpg}}\\ +
- +
-  - Several Events have been created and highlighted on the graphs.+
  
 ===== Creating Events Manually ===== ===== Creating Events Manually =====
- +  - Select the graph of the Z-component of the Ground Reaction Force signal by Left clicking on the graph. You will see the graph is now framed. \\ {{:tutorial6_2.jpg?850}} \\
-  - Select the graph of the Z-component of the Ground Reaction Force signal by Left clicking on the graph. You will see the graph is now framed.\\ +
-{{tutorial6_2.jpg}}\\ +
   - To create the event, double click on the Fz force signal at the frame that the signal rises above zero.   - To create the event, double click on the Fz force signal at the frame that the signal rises above zero.
-  - Enter the name **RON** into the popup dialog box. **RON** is a typical name used in Visual3D to indicate that the Right has contacted a force platform. **In principle** the event can be assigned any name, but when Visual3D computes Heel Strike and Toe Off automatically, the events are labeled ON and OFF.\\ +  - Enter the name **RON** into the popup dialog box. **RON** is a typical name used in Visual3D to indicate that the Right has contacted a force platform. **In principle** the event can be assigned any name, but when Visual3D computes Heel Strike and Toe Off automatically, the events are labeled ON and OFF. \\ {{:tutorial6_3.jpg?850}} \\
-{{tutorial6_3.jpg}}\\ +
   - An event labeled **RON** has been added to the Event_Label data tree.   - An event labeled **RON** has been added to the Event_Label data tree.
-  - To highlight this event (actually all occurrences of this event), select the RON signal with a Right Mouse Button click and select **Highlight Event on Graphs.** The Frames corresponding to RON will be highlighted in yellow on all signals in each graph.\\ +  - To highlight this event (actually all occurrences of this event), select the RON signal with a Right Mouse Button click and select **Highlight Event on Graphs.** The Frames corresponding to RON will be highlighted in yellow on all signals in each graph. \\ {{:tutorial6_4.jpg?850}} \\
-{{tutorial6_4.jpg}}\\ +
  
 ==== Create Events Dialog ==== ==== Create Events Dialog ====
  
-{{CreateEventIcon.jpg}}+{{:CreateEventIcon.jpg}}
  
-{{CreateEventDialog.jpg}}+{{:CreateEventDialog.jpg}}
  
 ==== Using TPR to identify other instances ==== ==== Using TPR to identify other instances ====
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 |**/Tolerance=**             |The "goodness of fit" for the match.                                                                          | |**/Tolerance=**             |The "goodness of fit" for the match.                                                                          |
  
-{{Eventtprdlg.gif}}+{{:Eventtprdlg.gif}}
  
 Dialog that pops up when pipeline selection is edited by double clicking with the left mouse button. Dialog that pops up when pipeline selection is edited by double clicking with the left mouse button.
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 First, transform the right and left heel and toe markers into the pelvis segment coordinate system. (this removes the need to specify the direction that the subject is walking). This can be accomplished using the model based item [[Visual3D:Documentation:Pipeline:Model_Based_Data_Commands:TARGET_PATH|TARGET_PATH]]. The images below show the settings used. First, transform the right and left heel and toe markers into the pelvis segment coordinate system. (this removes the need to specify the direction that the subject is walking). This can be accomplished using the model based item [[Visual3D:Documentation:Pipeline:Model_Based_Data_Commands:TARGET_PATH|TARGET_PATH]]. The images below show the settings used.
  
-{{RightHeelWrtPelvis.jpg}}+{{:RightHeelWrtPelvis.jpg}}
  
-{{LeftHeelWrtPelvis.jpg}}+{{:LeftHeelWrtPelvis.jpg}}
  
-{{RightToeWrtPelvis.jpg}}+{{:RightToeWrtPelvis.jpg}}
  
-{{LeftToeWrtPelvis.jpg}}+{{:LeftToeWrtPelvis.jpg}}
  
 === Method 1. Coordinate Based Algorithm === === Method 1. Coordinate Based Algorithm ===
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 </code> </code>
  
-{{RHS.jpg}}+{{:RHS.jpg}}
  
 the yellow tick represents RON from the force platform signal. the yellow tick represents RON from the force platform signal.
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 </code> </code>
  
-{{LHS.jpg}}+{{:LHS.jpg}}
  
 the yellow tick represents ROFF from the force platform signal. the yellow tick represents ROFF from the force platform signal.
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 </code> </code>
  
-{{RTO.jpg}}+{{:RTO.jpg}}
  
 the yellow tick represents ROFF from the force platform signal. the yellow tick represents ROFF from the force platform signal.
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 </code> </code>
  
-{{LTO.jpg}}+{{:LTO.jpg}}
  
 the yellow tick represents LOFF from the force platform signal. the yellow tick represents LOFF from the force platform signal.
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 === Method 2. Velocity Based Algorithm === === Method 2. Velocity Based Algorithm ===
  
-The velocity based algorithm is essentially t=he same. The zero crossing of the first derivative to the model based items computed above (LHEEL_WRT_PELVIS, RHEEL_WRT_PELVIS, RTOE_WRT_PELVIS, and LTOE_WRT_PELVIS) are computed.+The velocity based algorithm is essentially the same. The zero crossing of the first derivative to the model based items computed above (LHEEL_WRT_PELVIS, RHEEL_WRT_PELVIS, RTOE_WRT_PELVIS, and LTOE_WRT_PELVIS) are computed.
  
 <code> <code>
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 </code> </code>
  
-{{RHS2.jpg}}+{{:RHS2.jpg}}
  
 == Right Toe Off == == Right Toe Off ==
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 </code> </code>
  
-{{RTO2.jpg}}+{{:RTO2.jpg}}
  
 == Left Heel Strike == == Left Heel Strike ==
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 </code> </code>
  
-{{LHS2.jpg}}+{{:LHS2.jpg}}
  
 == Left Toe Off == == Left Toe Off ==
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 </code> </code>
  
-{{LTO2.jpg}}+{{:LTO2.jpg}}
  
 As can be observed the results for Control data are very good. As can be observed the results for Control data are very good.
visual3d/tutorials/events/gait_events.1720028717.txt.gz · Last modified: 2024/07/03 17:45 by sgranger