Event Maximum

Event Maximum

Overview

The Event_Maximum command is used to detect the maximum value of a specified signal within a defined event sequence or range and create an event at that location. This command can evaluate different components of a signal (X, Y, Z, Residual) and can apply offsets to shift the detected event if needed.

Useful for identifying peak forces, peak joint angles, or maximum accelerations during specific phases of a motion, such as between initial contact and toe-off during gait.
If the global maxima are needed, see the Event_Global_Maximum command
To review the difference between local and global maximum values please see here

Pipeline Command

The command below is as seen in the Visual3D application:

Event_Maximum
/RESULT_EVENT_NAME=
! /SIGNAL_TYPES=
! /SIGNAL_FOLDER=ORIGINAL
! /SIGNAL_NAMES=
! /SIGNAL_COMPONENTS=
! /FRAME_OFFSET=0
! /TIME_OFFSET=
! /EVENT_SEQUENCE=
! /EXCLUDE_EVENTS=
! /EVENT_SEQUENCE_INSTANCE=0
! /EVENT_SUBSEQUENCE=
! /SUBSEQUENCE_EXCLUDE_EVENTS=
! /EVENT_SUBSEQUENCE_INSTANCE=0
! /EVENT_INSTANCE=0
! /FRAME_WINDOW=8
! /THRESHOLD=
;

Command Parameters

The following table shows the command parameters and descriptions:

Parameter	Description
/RESULT_EVENT_NAME=	The name assigned to the detected peak event.
!/SIGNAL_TYPES=	Indicates type of signal analyzed.
!/SIGNAL_FOLDER=ORIGINAL	Specifies the folder containing the target signal (typically ORIGINAL)
!/SIGNAL_NAMES=	The name of the signal to analyze.
!/SIGNAL_COMPONENTS	Which components to evaluate (X, Y, Z, Residual)
!/FRAME_OFFSET=	Optional offset in frames to shift the detected event.
!/TIME_OFFSET=	Optional offset in seconds to shift the detected event.
!/EVENT_SEQUENCE=	Defines the sequence of events used.
!/EXCLUDE_EVENTS=	Events to exclude within the sequence.
!/EVENT_SEQUENCE_INSTANCE=0	Specifies which instance of the sequence to evaluate (0 to consider ALL)
!/EVENT_SUBSEQUENCE=	Defines a smaller sequence within the main even sequence.
!/SUBSEQUENCE_EXCLUDE_EVENTS	Events to exclude from the subsequence.
!/EVENT_SUBSEQUENCE_INSTANCE=0	Specifies which instance of the subsequence to evaluate.
!/EVENT_INSTANCE=	Specifies which instance of the event to label (0 for all, positive for first occurrences, negative for last occurrences).
!/FRAME_WINDOW=	Number of frames around the maximum that must satisfy the threshold.
!/THRESHOLD=	Defines the minimum value the signal must reach to qualify as a peak.

Dialog

The command can be edited in a text editor or in the dialog. To edit in the dialog, click on the Edit button in the pipeline workshop or double-click on the pipeline command. The dialog is shown below:

Examples

The following examples will go through the use of the Event_Maximum command in the Visual3D application.

Example 1: Simple Use Case

The first example will cover the command using the dialog as well as the command text. To create the RKFlex_MaxLocal event using the Event_Maximum dialog box:

1. Add the Event_Maximum command to the pipeline. Then, enter information into dialog box:

Event_Name: RKFlex_MaxLocal
Select Frame Offset: 0
Signal Components: X
Event Sequence:RHS → RHS (use arrows to move from defined events list into sequence.)
Event Sequence Instance:0

2. Close the dialog, on the Signals and Events tab, select the desired signal from the data tree, in this case Right_Knee_Angle. Navigate into the LINK_MODEL_BASED items folder, and select the checkbox beside the signal.

3. Open the pipeline workshop again, and then click on Import Selected Signals.

RKFlex_Max will be created at the minimum value during the gait cycle within the specified frame window.

Notes

Version 5

In version 5 the command has been extended to include the Event_Sequence and Exclude_Events parameters.

Event_Maximum
/RESULT_EVENT_NAME=EVENT_MAX
/SIGNAL_TYPES=TARGET
/SIGNAL_FOLDER=ORIGINAL
/SIGNAL_NAMES=LFT2
/SIGNAL_COMPONENTS=Z
/FRAME_OFFSET=0
!/TIME_OFFSET=
!/EVENT_SEQUENCE=
!/EXCLUDE_EVENTS=
!/EVENT_SEQUENCE_INSTANCE=0
!/EVENT_SUBSEQUENCE=
!/SUBSEQUENCE_EXCLUDE_EVENTS=
!/EVENT_INSTANCE=0
!/FRAME_WINDOW-8
/THRESHOLD=0.14
;

Other options within the command such as Exclude Event, and Select Subsequence are explained in detail on the Event_Global_Maximum page.
If /Threshold is empty, all local maximum are identified.
If /Threshold has a value or expression, only local maximum that are greater than the threshold are identified.

Version 4

Event_Maximum
/Signal_Types=The type of signal to be evaluated
/Signal_Names=The names of the signals to be evaluated
/Signal_Folder=The name of the signal folder
/Event_Name=The name to be given to the threshold event
/Select_X=(True or False)Use this component of the signal
/Select_Y=(True or False)Use this component of the signal
/Select_Z=(True or False)Use this component of the signal
/Frame_Window=The range of frames of data that must be below the maximum
/Start_At_Event=The search begins from the start event
/End_At_Event=The search ends at the end event
/Event_Instance=
;

Dialog that pops up when pipeline selection is edited by double clicking with the left mouse button.

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