Publications by authors named "I A Kougioumtzoglou"
Background: Preeclampsia is associated with autonomic dysregulation during pregnancy; however, less is known about autonomic function in the first week postpartum after preeclampsia.
Methods: We retrospectively analyzed data from a prospective cohort of women with and without preeclampsia. Continuous blood pressure and heart rate were measured with finger plethysmography within 7 days postpartum.
Article Synopsis
- The study investigates how changes in dynamic cerebral autoregulation (DCA) affect mothers after experiencing severe preeclampsia postpartum, compared to healthy postpartum and non-pregnant women.
- Researchers used techniques like transcranial Doppler and blood pressure monitoring to measure DCA parameters within a week of delivery in these groups.
- Results indicated that postpartum participants showed faster autoregulatory responses but with impaired dampening effects, suggesting a hyperdynamic state in DCA regardless of preeclampsia status.
A data-driven technique for parsimonious modeling and analysis of dynamic cerebral autoregulation (DCA) is developed based on the concept of diffusion maps. Specifically, first, a state-space description of DCA dynamics is considered based on arterial blood pressure, cerebral blood flow velocity, and their time derivatives. Next, an eigenvalue analysis of the Markov matrix of a random walk on a graph over the dataset domain yields a low-dimensional representation of the intrinsic dynamics.
View Article and Find Full Text PDFA Wiener path integral variational formulation with free boundaries is developed for determining the stochastic response of high-dimensional nonlinear dynamical systems in a computationally efficient manner. Specifically, a Wiener path integral representation of a marginal or lower-dimensional joint response probability density function is derived. Due to this marginalization, the associated computational cost of the technique becomes independent of the degrees of freedom (d.
View Article and Find Full Text PDFObjective: To develop a joint time-frequency analysis technique based on generalized harmonic wavelets (GHWs) for dynamic cerebral autoregulation (DCA) performance quantification.
Approach: We considered two groups of human subjects to develop and validate the method: 55 healthy volunteers and 35 stroke-free subjects with unilateral internal carotid artery stenosis (CAS). We determined the mean and coherence-weighted average of the phase shift (PS) of appropriately defined GHW-based transfer functions, based on data points over the joint time-frequency domain.