Hi,
To denoise Electrocardiogram (ECG) signals using Hilbert-Huang transform (HHT) in MATLAB:
Load your ECG data:
ecg_data = load('your_ecg_data.mat');
Apply Empirical Mode Decomposition (EMD) using a custom function:
imfs = emd(ecg_data);
Denoise the intrinsic mode functions (IMFs) using a threshold:
for i = 1:length(imfs)
    if energy(imfs(i)) < threshold
        imfs(i) = 0;
    end
end
Reconstruct the denoised ECG signal:
denoised_ecg = sum(imfs);
Apply Hilbert Transform:
analytic_signal = hilbert(denoised_ecg);
This outline is simplified, and you may need to adapt it according to your specific needs and data. 
- MATLAB does not provide a built-in emd function, so you'll need to source this elsewhere.
- The threshold used in step 3 may need to be adjusted according to the specific needs and data2.
- The hilbert function in MATLAB returns the analytic signal, not the Hilbert spectrum.
- Note that the energy function is not a built-in MATLAB function, so you'll need to define it yourself or use a different method to calculate the energy of the IMFs.


