High resolution R-R interval measurement

R-R interval measurement from digitized ECG signal has an inherent error due to the finite sampling frequency. This error causes distortion of heart rate variability (HRV) power spectrum. Results of implementation of an algorithm designed to increase the resolution of R-R interval measurement are reported. The algorithm first estimates the R-R intervals with a finite resolution accuracy. Then the interval truncation error caused by the finite sampling frequency is estimated. The performance of the algorithm was evaluated on an artificial signal, generated by the IPFM model. The results of the simulation indicate that the algorithm increases the resolution of R-R interval measurement even in the presence of noise. Measurement of R-R interval with high resolution may improve the reliability of HRV power spectrum estimation especially when dealing with low sampling frequency of the ECG signal (e.g. Holter tapes)