title: Point process time-frequency analysis of respiratory sinus arrhythmia under altered respiration dynamics.
abstract: Respiratory sinus arrhythmia (RSA) is largely mediated by the autonomic nervous system through its modulating influence on the heartbeat. We propose an algorithm for quantifying instantaneous RSA as applied to heart beat interval and respiratory recordings under dynamic respiration conditions. The blood volume pressure derived heart beat series (pulse intervals, PI) are modeled as an inverse gaussian point process, with the instantaneous mean PI modeled as a bivariate regression incorporating both past PI and respiration values observed at the beats. A point process maximum likelihood algorithm is used to estimate the model parameters, and instantaneous RSA is estimated by a frequency domain transfer function approach. The model is statistically validated using Kolmogorov-Smirnov (KS) goodness-of-fit analysis, as well as independence tests. The algorithm is applied to subjects engaged in meditative practice, with distinctive dynamics in the respiration patterns elicited as a result. Experimental results confirm the ability of the algorithm to track important changes in cardiorespiratory interactions elicited during meditation, otherwise not evidenced in control resting states.
authors.affiliation: Applied Signal Processing Group, School of Engineering, The Australian National University, Canberra, Australia. sandun.kodituwakku@anu.edu.au
authors.forename: Sandun
authors.initials: S
authors.lastname: Kodituwakku
authors.forename: Sara W
authors.initials: SW
authors.lastname: Lazar
authors.forename: Premananda
authors.initials: P
authors.lastname: Indic
authors.forename: Emery N
authors.initials: EN
authors.lastname: Brown
authors.forename: Riccardo
authors.initials: R
authors.lastname: Barbieri
mesh_terms: D001146:Arrhythmia, Sinus / Q000503:physiopathology; D001794:Blood Pressure; D003198:Computer Simulation; D006339:Heart Rate; D006801:Humans; D008954:Models, Biological; D015233:Models, Statistical; D015656:Respiratory Mechanics