The sXYYYZ.nks.zip files, where X is the number of ECG leads, YYY is the patient number, and Z is the record number of this patient, are compressed ASCII files and contain: - Time series of ST segment normalized Karhunen-Loeve (KL) coefficients. Normalization was performed by dividing coefficients by their standard deviations. The KL basis functions were applied to each normal and non-noisy heart beat (in each ECG lead) of the records of the LTST DB which passed the database's preprocessing phase during its development. The KL basis functions are of length of 32 samples (128 ms) and were applied to ST segment in each ECG lead from the point FP + 40ms to the point FP + 168 ms where FP is the Aristotle's fiducial point. For each KL coefficient standard deviation was calculated over all leads of records and all records of the LTST DB (gross), and each coefficient for each heart beat in each lead of records was than divided by its standard deviation. Standard deviations (multiplied by 100) for the first nine KL coefficients are following: Coefficient 1: 11266.0190 Coefficient 2: 4228.7352 Coefficient 3: 2308.8288 Coefficient 4: 1091.9271 Coefficient 5: 714.7203 Coefficient 6: 573.7821 Coefficient 7: 579.2027 Coefficient 8: 518.2478 Coefficient 9: 536.0308 To unzip each sXYYYZ.nks.zip file type: unzip sXYYYZ.nks.zip Columns in the sXYYYZ.nks file (for two channel records, X = 2, RECORDS FROM s20011 TO s20651), represent: Column 1: Time index, Aristotle's fiducial point of the heart beat Column 2: ST segment normalized kl coeff. 1 for the lead 0 (multiplied by 100) Column 3: ST segment normalized kl coeff. 2 for the lead 0 (multiplied by 100) Column 4: ST segment normalized kl coeff. 3 for the lead 0 (multiplied by 100) Column 5: ST segment normalized kl coeff. 4 for the lead 0 (multiplied by 100) Column 6: ST segment normalized kl coeff. 5 for the lead 0 (multiplied by 100) Column 7: ST segment normalized kl coeff. 6 for the lead 0 (multiplied by 100) Column 8: ST segment normalized kl coeff. 7 for the lead 0 (multiplied by 100) Column 9: ST segment normalized kl coeff. 8 for the lead 0 (multiplied by 100) Column 10: ST segment normalized kl coeff. 9 for the lead 0 (multiplied by 100) Column 11: Residual error when using first 1 kl coeff. for reconstruction of the ST segment in the lead 0 Column 12: Residual error when using first 2 kl coeff. for reconstruction of the ST segment in the lead 0 Column 13: Residual error when using first 3 kl coeff. for reconstruction of the ST segment in the lead 0 Column 14: Residual error when using first 4 kl coeff. for reconstruction of the ST segment in the lead 0 Column 15: Residual error when using first 5 kl coeff. for reconstruction of the ST segment in the lead 0 Column 16: Residual error when using first 6 kl coeff. for reconstruction of the ST segment in the lead 0 Column 17: Residual error when using first 7 kl coeff. for reconstruction of the ST segment in the lead 0 Column 18: Residual error when using first 8 kl coeff. for reconstruction of the ST segment in the lead 0 Column 19: Residual error when using first 9 kl coeff. for reconstruction of the ST segment in the lead 0 Column 20: ST segment normalized kl coeff. 1 for the lead 1 (multiplied by 100) Column 21: ST segment normalized kl coeff. 2 for the lead 1 (multiplied by 100) Column 22: ST segment normalized kl coeff. 3 for the lead 1 (multiplied by 100) Column 23 ST segment normalized kl coeff. 4 for the lead 1 (multiplied by 100) Column 24: ST segment normalized kl coeff. 5 for the lead 1 (multiplied by 100) Column 25: ST segment normalized kl coeff. 6 for the lead 1 (multiplied by 100) Column 26: ST segment normalized kl coeff. 7 for the lead 1 (multiplied by 100) Column 27: ST segment normalized kl coeff. 8 for the lead 1 (multiplied by 100) Column 28: ST segment normalized kl coeff. 9 for the lead 1 (multiplied by 100) Column 29: Residual error when using first 1 kl coeff. for reconstruction of the ST segment in the lead 1 Column 30: Residual error when using first 2 kl coeff. for reconstruction of the ST segment in the lead 1 Column 31: Residual error when using first 3 kl coeff. for reconstruction of the ST segment in the lead 1 Column 32: Residual error when using first 4 kl coeff. for reconstruction of the ST segment in the lead 1 Column 33: Residual error when using first 5 kl coeff. for reconstruction of the ST segment in the lead 1 Column 34: Residual error when using first 6 kl coeff. for reconstruction of the ST segment in the lead 1 Column 35: Residual error when using first 7 kl coeff. for reconstruction of the ST segment in the lead 1 Column 36: Residual error when using first 8 kl coeff. for reconstruction of the ST segment in the lead 1 Column 37: Residual error when using first 9 kl coeff. for reconstruction of the ST segment in the lead 1 Columns in the sXYYYZ.nks file (for three channel records, X = 3, RECORDS FROM s30661 TO s30801), represent: Column 1: Time index in [ms], Aristotle's fiducial point of the heart beat Column 2: ST segment normalized kl coeff. 1 for the lead 0 (multiplied by 100) Column 3: ST segment normalized kl coeff. 2 for the lead 0 (multiplied by 100) Column 4: ST segment normalized kl coeff. 3 for the lead 0 (multiplied by 100) Column 5: ST segment normalized kl coeff. 4 for the lead 0 (multiplied by 100) Column 6: ST segment normalized kl coeff. 5 for the lead 0 (multiplied by 100) Column 7: ST segment normalized kl coeff. 6 for the lead 0 (multiplied by 100) Column 8: ST segment normalized kl coeff. 7 for the lead 0 (multiplied by 100) Column 9: ST segment normalized kl coeff. 8 for the lead 0 (multiplied by 100) Column 10: ST segment normalized kl coeff. 9 for the lead 0 (multiplied by 100) Column 11: Residual error when using first 1 kl coeff. for reconstruction of the ST segment in the lead 0 Column 12: Residual error when using first 2 kl coeff. for reconstruction of the ST segment in the lead 0 Column 13: Residual error when using first 3 kl coeff. for reconstruction of the ST segment in the lead 0 Column 14: Residual error when using first 4 kl coeff. for reconstruction of the ST segment in the lead 0 Column 15: Residual error when using first 5 kl coeff. for reconstruction of the ST segment in the lead 0 Column 16: Residual error when using first 6 kl coeff. for reconstruction of the ST segment in the lead 0 Column 17: Residual error when using first 7 kl coeff. for reconstruction of the ST segment in the lead 0 Column 18: Residual error when using first 8 kl coeff. for reconstruction of the ST segment in the lead 0 Column 19: Residual error when using first 9 kl coeff. for reconstruction of the ST segment in the lead 0 Column 20: ST segment normalized kl coeff. 1 for the lead 1 (multiplied by 100) Column 21: ST segment normalized kl coeff. 2 for the lead 1 (multiplied by 100) Column 22: ST segment normalized kl coeff. 3 for the lead 1 (multiplied by 100) Column 23 ST segment normalized kl coeff. 4 for the lead 1 (multiplied by 100) Column 24: ST segment normalized kl coeff. 5 for the lead 1 (multiplied by 100) Column 25: ST segment normalized kl coeff. 6 for the lead 1 (multiplied by 100) Column 26: ST segment normalized kl coeff. 7 for the lead 1 (multiplied by 100) Column 27: ST segment normalized kl coeff. 8 for the lead 1 (multiplied by 100) Column 28: ST segment normalized kl coeff. 9 for the lead 1 (multiplied by 100) Column 29: Residual error when using first 1 kl coeff. for reconstruction of the ST segment in the lead 1 Column 30: Residual error when using first 2 kl coeff. for reconstruction of the ST segment in the lead 1 Column 31: Residual error when using first 3 kl coeff. for reconstruction of the ST segment in the lead 1 Column 32: Residual error when using first 4 kl coeff. for reconstruction of the ST segment in the lead 1 Column 33: Residual error when using first 5 kl coeff. for reconstruction of the ST segment in the lead 1 Column 34: Residual error when using first 6 kl coeff. for reconstruction of the ST segment in the lead 1 Column 35: Residual error when using first 7 kl coeff. for reconstruction of the ST segment in the lead 1 Column 36: Residual error when using first 8 kl coeff. for reconstruction of the ST segment in the lead 1 Column 37: Residual error when using first 9 kl coeff. for reconstruction of the ST segment in the lead 1 Column 38: ST segment normalized kl coeff. 1 for the lead 2 (multiplied by 100) Column 39: ST segment normalized kl coeff. 2 for the lead 2 (multiplied by 100) Column 40: ST segment normalized kl coeff. 3 for the lead 2 (multiplied by 100) Column 41 ST segment normalized kl coeff. 4 for the lead 2 (multiplied by 100) Column 42: ST segment normalized kl coeff. 5 for the lead 2 (multiplied by 100) Column 43: ST segment normalized kl coeff. 6 for the lead 2 (multiplied by 100) Column 44: ST segment normalized kl coeff. 7 for the lead 2 (multiplied by 100) Column 45: ST segment normalized kl coeff. 8 for the lead 2 (multiplied by 100) Column 46: ST segment normalized kl coeff. 9 for the lead 2 (multiplied by 100) Column 47: Residual error when using first 1 kl coeff. for reconstruction of the ST segment in the lead 2 Column 48: Residual error when using first 2 kl coeff. for reconstruction of the ST segment in the lead 2 Column 49: Residual error when using first 3 kl coeff. for reconstruction of the ST segment in the lead 2 Column 50: Residual error when using first 4 kl coeff. for reconstruction of the ST segment in the lead 2 Column 51: Residual error when using first 5 kl coeff. for reconstruction of the ST segment in the lead 2 Column 52: Residual error when using first 6 kl coeff. for reconstruction of the ST segment in the lead 2 Column 53: Residual error when using first 7 kl coeff. for reconstruction of the ST segment in the lead 2 Column 54: Residual error when using first 8 kl coeff. for reconstruction of the ST segment in the lead 2 Column 55: Residual error when using first 9 kl coeff. for reconstruction of the ST segment in the lead 2