Goal: Learn how the muscle signal is collected and processed

• Chapter 12 on Surface Electromyography in: John T. Cacioppo, Louis G. Tassinary, Gary G. Berntson - Handbook of Psychophysiology (Cambridge University Press, 2007). The most important parts:
  • Physical context (pp. 271-273)
  • Signal detection (pp. 273-277)
    • No, we will not place electrodes on the face, so there is no need to remember this part.
  • Inferential context (pp. 282-284)
  • Applications (pp. 288-290)

1. Q&A Session:
   1. What do we measure with electromyography?
   2. What are the two main types of EMG sensors?
   3. How many electrodes do we use in an EMG measurement?
2. Measurement time:
   1. The electrode placement for the EMG signal is straightforward: the two sensor electrodes are placed on the muscle (e.g., biceps; see page 7 in EMG User Manual), and the reference electrode is placed in the area of low muscle activity (e.g., on the elbow, on the knee, etc.)
      1. Important: The sensor has only two electrodes, therefore, in addition to the sensor, the reference electrode (single electrode with no stickers) must be also connected (to the socket marked with an arrow in the biosignalsplux hub)
   2. Follow the Devices 101 lab to connect the biosignalsplux with the PC
   3. Use the EMG Datasheet and EMG User Manual to properly record the EMG signal
   4. Tasks:
      1. The EMG signal can be analyzed binarily (activity vs. inactivity), but you can also differentiate between many intermediate states that depend on the strength of muscle tightening. See if you are able to generate different EMG amplitudes by manipulating your muscle!
      2. As a learning practice, we attach EMG electrodes to the biceps because muscle activity is very strong there, but EMG can be used to measure the activity of any muscle - check out the other one!
      3. Why does the reference electrode need to be in a location where there is no muscle activity? What happens when we place it on the same muscle? What happens when we place it on a different muscle? (in the latter case, it is worth checking how the signal changes when we move the “measured” muscle, how when we move the “reference” muscle, and how when we move both at the same time)
   5. At the end of class:
      1. clean the equipment with disinfectant wipes
      2. throw away the disposable electrodes (or keep them as souvenirs )
      3. pack all items in bags
      4. make sure all items are in the case:
         • biosignalsplux hub
         • bluetooth dongle
         • 4 sensors (each has a sticker with the name on it)
         • reference electrode (single, no stickers)
         • power supply
      5. give the case to the teacher
3. Practice session:
   1. Today's lab is placed in one Jupyter Notebook: Electromyography (EMG)

• Chapter 12 on Surface Electromyography in: John T. Cacioppo, Louis G. Tassinary, Gary G. Berntson - Handbook of Psychophysiology (Cambridge University Press, 2016) – great handbook if you want to know more about all the physiology behind analysed signals (3rd edition available online via EBSCO)
• Simao et al. - A Review on Electromyography Decoding and Pattern Recognition for Human-Machine Interaction (IEEE Access, 2019)
• Spiewak et al. - A Comprehensive Study on EMG Feature Extraction and Classifiers (OAJBEB, 2018)
• Solnik et al. - Teager–Kaiser energy operator signal conditioning improves EMG onset detection (European Journal of Applied Physiology, 2010)

• NeuroKit2 (toolbox for BVP, ECG, EDA, EEG, EMG, EOG, Respiration; it has a physiological signal generator)
• BioSPPy (toolbox for BVP, ECG, EDA, EEG, EMG, Respiration)