Summary of "ECG Filtration and Normalization in MATLAB | MATLAB Digital Signal Processing"

The video provides a tutorial on ECG signal filtration and normalization using MATLAB, focusing on Digital Signal Processing techniques applied to physiological data.

Key Technological Concepts and Procedures:

Loading ECG Data:
- The ECG data is sourced from the PhysioNet open-source dataset.
- Data is loaded from a local file (100.dat) using MATLAB’s fopen, fread (with 16-bit integer format), and fclose functions.
- Sampling frequency (Fs) is 360 Hz.
- A time vector is created based on the sampling rate and signal length for plotting.
Raw ECG Signal Visualization:
- The raw ECG waveform is plotted for a 5-second segment to avoid clutter and improve interpretability.
Bandpass Filtering:
- A Butterworth bandpass filter is applied to remove noise outside the typical ECG frequency range.
- Passband frequencies are set between 5 Hz (low cutoff) and 15 Hz (high cutoff).
- MATLAB’s built-in butter function is used to compute filter coefficients.
- The filter is applied using filtfilt for zero-phase filtering to avoid phase distortion.
R-Peak Detection:
- The filtered ECG signal is processed using MATLAB’s findpeaks function.
- A minimum peak height threshold (e.g., 200) is set to detect R-peaks.
- The number of detected beats is calculated and printed (e.g., ~17,000 beats).
Normalization of ECG Signal:
- The amplitude of the filtered ECG is normalized to a range of -1 to 1.
- Normalization formula: Normalized = 2 × (signal - min(signal)) / (max(signal) - min(signal)) - 1
- This standardizes the signal amplitude for easier analysis and comparison.
Plotting Normalized Signal:
- The normalized ECG signal is plotted for visualization.
- The tutorial suggests using global variables to avoid repeating code for plotting multiple segments.
Additional Notes:
- The presenter briefly mentions simulating ECG signals using sine wave functions but does not delve into details.
- Code snippets are made available on the presenter’s website with a link provided in the video description.
- Viewers are encouraged to ask questions in the comments.