====== Removing DC Bias ======

===== Background =====

Normalize to greatest ½ second activity during 5 second trial. A window of twenty-five .02 second intervals of integrated EMG is moved one interval at a time across the 5 seconds of data to find the greatest EMG. The average integrated EMG during the ½ second is used to compute the normalization factor.

This is just an example, so the user should modify the meta-command to suit their own needs.

The task is as follows:

  * Compute a normalization factor
  * Normalize to greatest ½ second during 5 second trial.\\
This is accomplished by using an average filter (see the bottom of the page)
  * A window of twenty-five .02 second intervals of integrated EMG is moved one interval at a time across the 5 seconds of data to find the greatest EMG.
  * The average integrated EMG during the ½ second is used to compute the normalization factor.

\\


===== Examples =====

The following are examples of how to do the above task. The maximum value is calculated is a little different in the following examples. You should choose the method which makes the most sense to you.

==== Example 1: Single MVC Trial ====

  - Process EMG
    - High pass filter (remove DC offset)
    - Calculate RMS of predetermined time intervals (example: 0.02 seconds)
  - Normalize
    - Calculate the average of the processed signal over 30 second intervals
    - Get the maximum of the 30 second interval
    - Normalize by dividing the average by the maximum

=== Download ===

[[https://www.has-motion.com/download/examples/EMG/MVC_Trial_Max_Mean_Example_2.zip|You can download the sample files here.]]

The download contains:

  * MVC_Example.cmz with -
    * 3 MVC trial
    * 2 Dynamic Trials
  * EMG_Norm_MVC_Max_Mean_Example_1.v3s (Example Pipeline Script)
  * EMG_Norm_MVC_Max_Mean_Example_1.v3m (Example Meta-Command)
  * Call_EMG_Norm_MVC_Max_Mean_Example_1_Meta.v3s (Example Pipeline Script calling Meta-Command)

==== Example 2: Multiple MVC Trials ====

  - Process EMG
    - High pass filter (remove DC offset)
    - Calculate RMS of predetermined time intervals (example: 0.02 seconds)
  - Normalize
    - Calculate the average of the processed signal over some time interval (in this example: 0.5 seconds)
    - Get the maximum of the processed signal
    - Calculate the maximum of the average signal
    - Normalize by dividing the processed signal by the maximum average over the interval

=== Download ===

[[https://www.has-motion.com/download/examples/EMG/MVC_Trial_Max_Mean_Example_1.zip|You can download the sample files here.]]

The download contains:

  * MVC_Example.cmz with -
    * 3 MVC trial
    * 2 Dynamic Trials
  * EMG_Norm_MVC_Max_Mean_Example_1.v3s (Example Pipeline Script)
  * EMG_Norm_MVC_Max_Mean_Example_1.v3m (Example Meta-Command)
  * Call_EMG_Norm_MVC_Max_Mean_Example_1_Meta.v3s (Example Pipeline Script calling Meta-Command)