ge-chunyu/egg

Analyze EGG signals

This repo contains some scripts which analyze EGG signals and calculate the common EGG measurements in batch.

The scripts do the following things:

• high-pass the EGG signal using the threshold of 20 Hz
• detect single cycles in the EGG signal
• compute the dEGG signal and detect the dEGG peak during each cycle of the EGG signal
• get the positions of different events (e.g., opening, contact) using critical threshold
• calculate EGG measurements:
  • nCqc: normalized value of CQ using the critical threshold method
  • nSqc: normalized value of SQ using the critical threshold method
  • nSqh: normalized value of SQ using the max contact and decontact in the EGG signal
  • nCqh: normalized value of CQ using the hybrid method (the peak of the dEGG signal and 0.25 threshold)
  • nPic: normalized value of PIC (peak increase in contact or DECPA), i.e., the amplitude of the dEGG peak
• also calculate Fo based on the EGG/dEGG signal
  • nFoc: Fo calculated by dividing the sampling frequency by the EGG cycle
  • nFov: Fo calculated by dividing the sampling frequency by the dEGG cycle

Some parameters of the scripts can be modified:

• freqCeiling: the maximum Fo
• maxThresh: the threshold of contact (default 0.9)
• noThresh: the threshold of no contact (default 0.1)
• openThresh: the threshold of opening (default 0.25)
• nPoint: the number of measurement points during each segment

Usage

Open analyzeEGG.m and change the path of EGG signals and the path of the corresponding TextGrid files. A file named cq.txt will be generated in the EGG folder.