Importance of correlation coefficient in ECG is to find the involved changes in the past & the present values ie if the normal BP of a person was a year back, a month back & today also is 70/110 instead of 80/120 then its not an issue of concern.(thats why Previous history is sometimes required)
Mean square error means the deviations from the standard value( with a large no. of observations) result in knowing the performance of heart.
Both these parameters are used to measure the effectiveness of ECG denoising algorithms. CCR measures how much the denoised signal (processed signal) is closely related to the input ECG signal. MSE measures the difference (error) between processed and input ECG signal. Input ECG signal refers a simulated ECG signal which is free from noise. Then noise is added to this simulated ECG to make the noisy ECG. denoising algorithms applied to this noisy ECG to denoise the ECG. Then processed ECG is compared with the original simulated ECG. These parameters measure the the algorithms ability to remove noise without affecting the real more crucial ECG segments.