visual3d:documentation:pipeline:metric_commands:metric_compute_temporal_distance
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| + | ====== Metric Compute Temporal Distance ====== | ||
| + | |||
| + | ====Overview==== | ||
| + | |||
| + | This pipeline computes the [[Visual3D: | ||
| + | |||
| + | If, for example, you have two groups of files (e.g. 2 TAGS) and you want to compute temporal distance metrics independently for each group. | ||
| + | * First, make one TAG active and set the output folder (GLOBAL_RESULT_METRIC_FOLDER) with a name reflecting the TAG. | ||
| + | * Second, make the other TAG active and set a unique output folder. | ||
| + | |||
| + | ===== Pipeline Command ===== | ||
| + | |||
| + | Command including default values. This command can be found in the **Pipeline Workshop** within the **Metric** folder. | ||
| + | |||
| + | < | ||
| + | Metric_Compute_Temporal_Distance | ||
| + | ! / | ||
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| + | ; | ||
| + | </ | ||
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| + | Note that the treadmill direction is new, and is specified as a unit vector. | ||
| + | |||
| + | ==== Legacy Treadmill Parameters ==== | ||
| + | |||
| + | If the subject is walking in the y-direction of the laboratory the unit vector would be: | ||
| + | |||
| + | Give the following legacy parameters | ||
| + | |||
| + | < | ||
| + | / | ||
| + | / | ||
| + | / | ||
| + | </ | ||
| + | |||
| + | The new parameter is: | ||
| + | |||
| + | / | ||
| + | |||
| + | ====Command Parameters==== | ||
| + | |||
| + | The following table shows the command parameters seen above and their descriptions: | ||
| + | |||
| + | |**GLOBAL_RESULT_METRIC_FOLDER**|**Name of metric result folder**| | ||
| + | |**CALCULATE_PER_FILE**|**Calculate average values across entire trial**| | ||
| + | |**CALCULATE_PER_ALL_CMO_GLOBALS**|**Calculate global average**| | ||
| + | |**CREATE_ALL_INSTANCES**|**value for each sequence (multiple values per trial)**| | ||
| + | |**CREATE_EMPTY_VALUES**|****| | ||
| + | |**RIGHT/ | ||
| + | |**HEIGHT**|**Signal type and name defining height**| | ||
| + | |**---_EVENT**|**Event signal names for foot on/off**| | ||
| + | |**STRICT_EVENT_SEQUENCE_VALIDATION**|**---**| | ||
| + | |**R/ | ||
| + | |**INCLUDE/ | ||
| + | |**EVENT_INSTANCE**|**Which instance of an event to use**| | ||
| + | |**COMPUTE_--------**|**Which values to be computed or excluded**| | ||
| + | |**TREADMILL_SPEED**|**Speed of treadmill used for recording (if applicable)**| | ||
| + | |**TREADMILL_DIRECTION**|**Direction of treadmill used for recording (if applicable)**| | ||
| + | |||
| + | ===== Temporal Distance Dialog ===== | ||
| + | |||
| + | The below dialog has been used within Visual3D as of v5. | ||
| + | |||
| + | ^ Dialog ^ Description ^ | ||
| + | |{{: | ||
| + | |{{: | ||
| + | |{{: | ||
| + | |{{: | ||
| + | |{{: | ||
| + | |||
| + | ====Examples==== | ||
| + | ===Simple example: Flight Time === | ||
| + | |||
| + | To use the **Compute Temporal Distance** command on gait cycle trials we must first identify key gait events. This can be done using the **Automatic Gait Events** command as shown below. | ||
| + | |||
| + | < | ||
| + | Automatic_Gait_Events | ||
| + | ! / | ||
| + | ! / | ||
| + | ! / | ||
| + | ; | ||
| + | </ | ||
| + | |||
| + | Now that key events in the gait cycle have been identified we can use the **Compute Temporal Distance** command to compute the mean left and right flight time for each trial. | ||
| + | |||
| + | Flight time is the average time from LTO to RHS (ensuring no LHS or RTO events occur between LTO and RHS) and RTO to LHS (ensuring no RHS or LTO events occur between RTO and LHS). | ||
| + | * Left flight time is calculated from LTO to RHS. | ||
| + | * Right flight time is calculated from RTO to LHS. | ||
| + | |||
| + | < | ||
| + | Metric_Compute_Temporal_Distance | ||
| + | ! / | ||
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| + | ; | ||
| + | </ | ||
| + | |||
| + | Once the pipeline has been executed you should see a new **TEMPORAL_DISTANCE** folder in the METRIC section of the Signals and Events tab. Within this folder you can find the mean flight time for the left and right sides. | ||
| + | |||
| + | {{: | ||
| + | |||
| + | ===Complex example: Comparing Left and Right Stride Length for treadmill trial=== | ||
| + | |||
| + | Here we will look at a gait cycle trial using data for users running on a treadmill and compare their mean stride length for the left and right sides. | ||
| + | |||
| + | Similarly to above, we will start by using **Automatic Gait Events** to define the gait cycle. | ||
| + | |||
| + | Next, we will use **Metric_Compute_Temporal_Distance** to compute the length of each stride for both sides, and adjust the command parameters to account for the speed of the single belt treadmill used to record the data. In this case the treadmill was moving at 1.25 m/s and the subject walking in the y-direction (0,1,0). | ||
| + | |||
| + | < | ||
| + | Metric_Compute_Temporal_Distance | ||
| + | ! / | ||
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| + | ; | ||
| + | </ | ||
| + | |||
| + | The computed stride data can now be found in the **Metric** folder under **Temporal_Distance**. | ||
| + | |||
| + | To compare the left and right stride lengths we will create a horizontal chart in the **Reports** tab. | ||
| + | |||
| + | Start by adding a new page to your report, and adding **Temporal and Distance Metrics** as an item. | ||
| + | |||
| + | {{: | ||
| + | |||
| + | Fill out the dialog box as so: | ||
| + | |||
| + | {{: | ||
| + | |||
| + | Click done. You should now see a bar chart comparing the left and right step length for your trial. | ||
| + | |||
| + | {{: | ||
| + | ===== Multisubject Support ===== | ||
| + | |||
| + | Versions of Visual3D more recent than v2022.08.1 support [[visual3d: | ||
| + | |||
| + | Older versions of Visual3D will not support the subject prefix extensions of this command and will treat each CMO/Z file as a single subject. In this way, the temporal and distance metrics are computed in the CMO/Z GLOBAL for the subject processed within that CMO. In the same manner, when computing the temporal and distance metrics across a library of subjects, each CMO/Z is treated as a single subject and then the subject averages are computed across CMO/Z files and placed into the workspace GLOBAL for the overall mean values across subjects. | ||
| + | |||
| + | ===== Temporal Distance Control Data ===== | ||
| + | |||
| + | The following are useful resources for temporal data metrics for Control Data Sets. | ||
| + | |||
| + | |**Lythgo N, Wilson C, Galea M(2009)** " | ||
| + | |//Gait and Posture 30, 2009, 502-506// | ||
| + | |This study investigated the basic spatio-temporal gaitmeasures of 898 primary school-aged children (5–13 years) and 82 young adults (18–27 years). Participants completed 6–8 walks at preferred speed alonga GAITRite walkway whilst barefoot and whilst wearing athletic shoes or runners. Outcome measures (non-normalized and normalized) were gait speed, cadence, step and stride length, support base, single and double support, stance duration, foot angle and associated symmetry measures. Non-normalized measures of speed, step and stride length, support base and foot angle increased with age whereas cadence reduced. Normalized measures remained unchanged with age in children whereas the young adults (both conditions) exhibited a 2.3% reduction in single support, a 5.1% increase in double support and a 2.6% increase in stance duration (p < 0.0001). For the entire sample, shoes increased walking speed by 8 cm/s, step length by 5.5 cm, stride length by 11.1 cm and base of support by 0.5 cm. In contrast, foot angle and cadence reduced by 0.18 and 3.9 steps/min respectively. Shoes increased both double support (1.6%) and stance time (0.8%), whereas single support reduced by 0.8%. Symmetry remained unaffected by age. On average, measures of step and stride symmetry (combining both conditions) fell around 0.7 cm, whereas measures of symmetry for step and stance time, single and double support fell around 0.6%. Footwear significantly affected gait (p < 0.0001). Gait may not be mature by age 13. Gait is symmetrical in healthy children and young adults but may change with pathology.| | ||
| + | |[[https:// | ||
| + | |**Lythgo N, Wilson C, Galea M(2011)** " | ||
| + | |//Gait and Posture 33, 2011, 29-35// | ||
| + | |This study recorded basic gait data from 656 healthy primary school-aged children (5–13 years) and 81 young adults (18–27 years) whilst walking over-ground across a level walkway at varying speed. It investigated the effect of gait speed and re-examined the issue of gait maturation. Participants completed 6–8 walks at self-selected slow, free and fast speed along a GAITRite walkway whilst wearing athletic shoes. Outcome measures (non-normalized and normalized) were gait speed, cadence, step and stride length, step and stride time, support base, single and double support (%), stance duration (%), foot angle and associated symmetry measures. Compared to free speed, participants walked 24% slower for the slow speed and 30% faster for the fast speed (p < 0.0001). Both normalized and non-normalized measures of cadence, step and stride length increased with speed (p < 0.001) whereas step and stride time reduced (p < 0.001). As a percentage of the gait cycle, single support and stance duration increased with speed (p < 0.001) whereas double support reduced (p < 0.001). Foot angle was significantly less (less toe-out) for the fast speed than the free and slow speeds (p < 0.001) whereas support base was unaffected by speed. Symmetry measures were unaffected by age or speed. Step and stride symmetry differentials (combining conditions) fell around 0.8 cm, whereas symmetry differentials for step and stance time, single and double support fell around 0.7%. This information can be used by clinicians and researchers to assess the gait of children.| | ||
| + | |[[https:// | ||
visual3d/documentation/pipeline/metric_commands/metric_compute_temporal_distance.1721230948.txt.gz · Last modified: 2024/07/17 15:42 by sgranger