Table 4.

Correlation and root mean squared error (RMSE) statistics of the digitised results from 87 3 by 1 ECG images and the ground truth digital ECGs before image thresholding (validation 2).

Lead name	Correlation				Root mean squared error
	Average	SD	p-value	95% confidence interval	Average	SD	p-value	95% confidence interval
I	0.863	0.201	$<0.001$	0.820–0.906	0.076	0.070	$<0.001$	0.061–0.091
II	0.907	0.206	$<0.001$	0.863–0.950	0.067	0.066	$<0.001$	0.053–0.081
V1	0.898	0.235	$<0.001$	0.848–0.948	0.068	0.095	$<0.001$	0.048–0.088