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Physiological Gaussian Process Priors for the Hemodynamics in fMRI Analysis [PDF]

, 2017
Background: Inference from fMRI data faces the challenge that the hemodynamic system that relates neural activity to the observed BOLD fMRI signal is unknown. New Method: We propose a new Bayesian model for task fMRI data with the following features: (i) joint estimation of brain activity and the underlying hemodynamics, (ii) the hemodynamics is ...
Eklund, Anders, Villani, Mattias, Wilzén, Josef   +2 more
arxiv   +3 more sources

Hemodynamically informed parcellation of cerebral FMRI data [PDF]

Acoustics, Speech and Signal Processing (ICASSP), 2014 IEEE International Conference on, May 2014, Florence, Italy. pp.2079 - 2083, 2015
Standard detection of evoked brain activity in functional MRI (fMRI) relies on a fixed and known shape of the impulse response of the neurovascular coupling, namely the hemodynamic response function (HRF). To cope with this issue, the joint detection-estimation (JDE) framework has been proposed.
Ciuciu, Philippe, Forbes, Florence, Frau-Pascual, Aina, Vincent, Thomas   +3 more
arxiv   +7 more sources

Sensitivity of coronary hemodynamics to vascular structure variations in health and disease [PDF]

Scientific Reports
Local hemodynamics play an essential role in the initiation and progression of coronary artery disease. While vascular geometry alters local hemodynamics, the relationship between vascular structure and hemodynamics is poorly understood.
Arnav Garcha, Noelia Grande Gutiérrez
doaj   +2 more sources

Acute and Long-Term Effects of Aortic Compliance Decrease on Central Hemodynamics: A Modeling Analysis

Frontiers in Physiology, 2021
Aortic compliance is an important determinant of cardiac afterload and a contributor to cardiovascular morbidity. In the present study, we sought to provide in silico insights into the acute as well as long-term effects of aortic compliance decrease on ...
Stamatia Pagoulatou, Dionysios Adamopoulos, Georgios Rovas, Vasiliki Bikia, Nikolaos Stergiopulos   +4 more
doaj   +1 more source

AI-Based Estimation of End-Systolic Elastance From Arm-Pressure and Systolic Time Intervals

Frontiers in Artificial Intelligence, 2021
Left ventricular end-systolic elastance (Ees) is a major determinant of cardiac systolic function and ventricular-arterial interaction. Previous methods for the Ees estimation require the use of the echocardiographic ejection fraction (EF).
Vasiliki Bikia, Dionysios Adamopoulos, Stamatia Pagoulatou, Georgios Rovas, Nikolaos Stergiopulos   +4 more
doaj   +1 more source

On the similarity between aortic and carotid pressure diastolic decay: a mathematical modelling study

Scientific Reports, 2023
Aortic diastolic pressure decay (DPD) has been shown to have considerable pathophysiological relevance in the assessment of vascular health, as it is significantly affected by arterial stiffening.
Vasiliki Bikia, Georgios Rovas, Sokratis Anagnostopoulos, Nikolaos Stergiopulos   +3 more
doaj   +1 more source

Validation of a Non-invasive Inverse Problem-Solving Method for Stroke Volume

Frontiers in Physiology, 2022
Stroke volume (SV) is a major biomarker of cardiac function, reflecting ventricular-vascular coupling. Despite this, hemodynamic monitoring and management seldomly includes assessments of SV and remains predominantly guided by brachial cuff blood ...
Vasiliki Bikia, Carmel M. McEniery, Emma Marie Roussel, Georgios Rovas, Stamatia Pagoulatou, Ian B. Wilkinson, Nikolaos Stergiopulos   +6 more
doaj   +1 more source

Quantification of the Phenomena Affecting Reflective Arterial Photoplethysmography

Bioengineering, 2023
Photoplethysmography (PPG) is a widely emerging method to assess vascular health in humans. The origins of the signal of reflective PPG on peripheral arteries have not been thoroughly investigated.
Georgios Rovas, Vasiliki Bikia, Nikolaos Stergiopulos   +2 more
doaj   +1 more source

Dual-slope imaging of cerebral hemodynamics with frequency-domain near-infrared spectroscopy [PDF]

Neurophoton. 10(1), 013508 (2023), 2022
Significance: This work targets the contamination of optical signals by superficial hemodynamics, which is one of the chief hurdles in non-invasive optical measurements of the human brain. Aim: To identify optimal source-detector distances for Dual-Slope (DS) measurements in Frequency-Domain (FD) Near-InfraRed Spectroscopy (NIRS) and demonstrate ...
arxiv   +1 more source

Mixed Valvular Disease Following Transcatheter Aortic Valve Replacement: Quantification and Systematic Differentiation Using Clinical Measurements and Image-Based Patient‐Specific In Silico Modeling [PDF]

, 2020
Background: Mixed valvular disease (MVD), mitral regurgitation (MR) from pre‐existing disease in conjunction with paravalvular leak (PVL) following transcatheter aortic valve replacement (TAVR), is one of the most important stimuli for left ventricle (LV)
Amrute, Junedh M., Ben-Assa, Eyal, Blanke, Philipp, Brown, Jonathan, de la Torre Hernandez, Jose M., Edelman, Elazer R., Garcia Camarero, Tamara, Keshavarz-Motamed, Zahra, Khodaei, Seyedvahid, Lee, Suk Joon, Leipsic, Jonathon, Rikhtegar Nezami, Farhad, Ruano Calvo, Javier, Sellers, Stephanie   +13 more
core   +1 more source