Upload the ECG as numpy array with shape=[2500,12,1] ([time, leads, 1]).
The voltage unit should be in 1 mv/unit and the sampling rate should be 250/second (total 10 second).
The leads should be ordered as follow I, II, III, aVR, aVL, aVF, V1, V2, V3, V4, V5, V6.