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HDsEMG units data processing

Hi there,

I am doing some data processing with the heat map data from the HDsEMG units. I have two questions:

  1. What is the sampling rate of the HDsEMG units heat map?
  2. Is there any initial data processing done for the heat map before the user receives the raw data? For example, are there any initial filters (ex. Bandpass) applied to the data?

Thank you!

Fabio ha reagito a questo messaggio.

Hi and thank you to have opened this ticket. We have to distinguish the heat maps between realtime acquisition and offline visualization. For real time you have just an ARV data processing of the signal before creating the heat map frame, this ARV is related to a sixteenth of a second (1/16), this mean that the software wait 125 raw samples, it estimates the ARV and it plot the heat map of that instant. For the offline it quite different, if you open the Activation Map processing you will be able to choose between "Raw" and ARV, in the first case all the samples will be used, and for each sample a frame will be created. With the ARV the signals is windowed in epochs, and this epoch value can be changed in the main page of offline visualization, and for each epoch the software estimates the ARV and create a frame. The default value of epoch is 0.5 (2 Hz) of sampling rate, and you can change it with any value. About the preprocessing, no software filters are used in the activation map, the only filters used are hardware filters but these are mandatory to select the bandpass of EMG signal between 10-500 Hz.