Pole-zero extraction by nonlinear regression of discrete-time arterial blood-flow waveforms

1984 ◽  
Vol 22 (3) ◽  
pp. 281-284 ◽  
Author(s):  
L. A. Meara
2013 ◽  
Vol 37 (4) ◽  
pp. 321-326 ◽  
Author(s):  
Marina Djelić ◽  
Sanja Mazić ◽  
Dejan Žikić

In the frame of a laboratory training course for medicine students, a new approach for laboratory exercises has been applied to teach the phenomena of circulation. The exercise program included measurements of radial artery blood flow waveform for different age groups using a noninvasive optical sensor. Arterial wave reflection was identified by measurements of blood flow waveforms before and after arterial branching. Students were able to distinguish between different waveforms of blood flow within different age groups. Furthermore, students were given the opportunity to explore the effect of aging on the elasticity of blood vessels. This exercise is an introduction to the fundamental physical laws of hemodynamics that can facilitate the learning and understanding of cardiovascular physiology to students of medicine.


2013 ◽  
Vol 23 (2) ◽  
Author(s):  
Xenia Descovich ◽  
Giuseppe Pontrelli ◽  
Sauro Succi ◽  
Simone Melchionna ◽  
Manfred Bammer

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 353
Author(s):  
Jayasree Nair ◽  
Lauren Davidson ◽  
Sylvia Gugino ◽  
Carmon Koenigsknecht ◽  
Justin Helman ◽  
...  

The optimal timing of cord clamping in asphyxia is not known. Our aims were to determine the effect of ventilation (sustained inflation–SI vs. positive pressure ventilation–V) with early (ECC) or delayed cord clamping (DCC) in asphyxiated near-term lambs. We hypothesized that SI with DCC improves gas exchange and hemodynamics in near-term lambs with asphyxial bradycardia. A total of 28 lambs were asphyxiated to a mean blood pressure of 22 mmHg. Lambs were randomized based on the timing of cord clamping (ECC—immediate, DCC—60 s) and mode of initial ventilation into five groups: ECC + V, ECC + SI, DCC, DCC + V and DCC + SI. The magnitude of placental transfusion was assessed using biotinylated RBC. Though an asphyxial bradycardia model, 2–3 lambs in each group were arrested. There was no difference in primary outcomes, the time to reach baseline carotid blood flow (CBF), HR ≥ 100 bpm or MBP ≥ 40 mmHg. SI reduced pulmonary (PBF) and umbilical venous (UV) blood flow without affecting CBF or umbilical arterial blood flow. A significant reduction in PBF with SI persisted for a few minutes after birth. In our model of perinatal asphyxia, an initial SI breath increased airway pressure, and reduced PBF and UV return with an intact cord. Further clinical studies evaluating the timing of cord clamping and ventilation strategy in asphyxiated infants are warranted.


2015 ◽  
Vol 26 (8) ◽  
pp. 2779-2789 ◽  
Author(s):  
Claus Christian Pieper ◽  
Winfried A. Willinek ◽  
Daniel Thomas ◽  
Hojjat Ahmadzadehfar ◽  
Markus Essler ◽  
...  

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