METHOD OF CARDIAC CYCLE START ASSIGNMENT Russian patent published in 2009 - IPC A61B5/402 

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely to cardiodiagnostics. A continuous electrocardiosignal is filtered and represented as discrete readouts. Among discrete readout, step of calculation of derivative k=0.01·f_d is specified, where f_d is sampling frequency. For each step, the derivative is calculated in modulus in all the deflections. Search interval of extrema is specified for the derived values of derivative signals. Each interval m is estimated for the greatest value of derivative signal. Then arithmetic average of the calculated values is determined. By comparing of the arithmetic average to the greatest values of derivative signals, artefacts are isolated and deleted, and threshold level P of the derivative signal is evaluated, while the derivative signals smaller than 0.3P are zeroed. The moment of derivative signal start t_i1 is estimated. The moment of derivative signal termination of a t_i2 is estimated. Then peak deflection R_i of electrocardiogram signal is calculated: . Thereby R-R intervals are assigned. R-R interval is divided into N parts, and value of the N-th part of the interval R_i,-R_i+1 is subtracted from the discrete readout R_i+1 and the derived discrete readout of electrocardiosignal is considered as the i-th cardiosignal start.

EFFECT: method allows improving accuracy of each cardiac cycle owing to more reliable assignment of electrocardiogram R-deflection.

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