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--- visual3d:documentation:emg:filtering:emg_envelope [2024/06/14 17:11] – created sgranger
+++ visual3d:documentation:emg:filtering:emg_envelope [2024/07/17 15:45] (current) – created sgranger
@@ Line 1: / Line 1: @@
-|**Language:**|** English**  • [[index.php?title=EMG_Envelope/fr&action=edit&redlink=1|français]] • [[index.php?title=EMG_Envelope/it&action=edit&redlink=1|italiano]] • [[EMG_Envelope/pt|português]] • [[index.php?title=EMG_Envelope/es&action=edit&redlink=1|español]] ****|
+====== EMG Envelope ======
-|===== Contents =====\\ \\ \\ \\ * [[#Using_the_Moving_RMS_Command|1 Using the Moving_RMS Command]]\\   * [[#Moving_RMS_using_Frame_Window|1.1 Moving RMS using Frame Window]]\\   * [[#Moving_RMS_using_Time_Window|1.2 Moving RMS using Time Window]]\\ * [[#Using_the_Moving_RMS_Command_to_Process_EMG_Data|2 Using the Moving_RMS Command to Process EMG Data]]|
+**If you are using a version of Visual3D older than 4.94, you will need to use the following commands to specify the frame window in seconds (as opposed to frames).**
-This page shows an example of processing EMG data using the Root Mean Square (RMS) Amplitude Method.
-===== Using the Moving_RMS Command =====
-==== Moving RMS using Frame Window ====
-For example the command below applies the moving RMS with a 51 frame window:
-<code>
-Moving_RMS
-/Signal_Types=ANALOG
-/Signal_Names=EMG1+EMG2+EMG3
-/Signal_Folder=PROCESSED
-/Num_Window_Frames= 51
-;
-</code>
-==== Moving RMS using Time Window ====
-When reporting RMS, it's typically stated as an RMS window over a specified time interval of T.
-An example of running an RMS over a 100 ms (0.1 seconds) window is achieved as:
-<code>
-! Moving RMS with 100ms window
-Moving_RMS
-/SIGNAL_TYPES=ANALOG
-/SIGNAL_NAMES=EMG1+EMG2+EMG3
-/SIGNAL_FOLDER=PROCESSED
-! /RESULT_SUFFIX=
-/RESULT_FOLDER=RMS
-/NUM_WINDOW_FRAMES= ( 0.1*PARAMETER::ANALOG::RATE ) + 1
-;
-</code>
-===== Using the Moving_RMS Command to Process EMG Data =====
-An example of "putting it all together". First the signal is Highpass filtered to remove the DC offset, then lowpass filtered and finally rectified:
 <code>
-! Apply a high pass filter with 50 Hz cutoff
+! -------------------------------------------
+! apply a bandpass filter to the EMG signals
+! -------------------------------------------
 Highpass_Filter
 /Signal_Types=ANALOG
@@ Line 57: / Line 20: @@
 ;
-! Apply a low pass filter with 500 Hz cutoff
 Lowpass_Filter
 /Signal_Types=ANALOG
@@ Line 70: / Line 32: @@
 /Num_Bidirectional_Passes=1
 ;
-! Moving RMS with 100ms window
+! -------------------------------------------
-Moving_RMS
+! copy the analog rate from the c3d parameter
-/SIGNAL_TYPES=ANALOG
+! to a metric value
-/SIGNAL_NAMES=EMG1+EMG2+EMG3
+! -------------------------------------------
+Metric_From_Parameter
+/METRIC_NAME=ANALOG_RATE
+/PARAMETER_GROUP=ANALOG
+/PARAMETER_NAME=RATE
+;
+! -------------------------------------------
+! compute the number of frames equivalent to
+! a 100 ms window
+! -------------------------------------------
+Evaluate_Expression
+/EXPRESSION=1+0.1*METRIC::PROCESSED::ANALOG_RATE
+/RESULT_NAME=RMS_FRAMES
+/RESULT_TYPE=METRIC
+! /RESULT_FOLDER=PROCESSED
+;
+! -------------------------------------------
+! create a pipeline parameter of the RMS window
+! -------------------------------------------
+Set_Pipeline_Parameter_To_Data_Value
+/PARAMETER_NAME=RMS_FRAMES
+/SIGNAL_TYPES=METRIC
+/SIGNAL_NAMES=RMS_FRAMES
 /SIGNAL_FOLDER=PROCESSED
-! /RESULT_SUFFIX=
+;
-/RESULT_FOLDER=RMS
-/NUM_WINDOW_FRAMES= ( 0.1*PARAMETER::ANALOG::RATE ) + 1
-;
-</code>
-[[Visual3D:Documentation:EMG:Filtering:EMG_Envelope_Version_2|If you are using a version of Visual3D older than 4.94, you can use the example here.]]
+! --------------------------------------------
+! compute a moving rms with a window of 100 ms
+! --------------------------------------------
+Moving_RMS
+/SIGNAL_TYPES=ANALOG
+/SIGNAL_NAMES=EMG1+EMG2+EMG3
+/SIGNAL_FOLDER=PROCESSED
+! /RESULT_SUFFIX=
+/RESULT_FOLDER=RMS
+/NUM_WINDOW_FRAMES=::RMS_FRAMES
+;
+</code>
-Retrieved from ""