Echocardiogram is vital for the diagnosis of cardiac disease. The heart has complex hemodynamics requiring an advanced ultrasound imaging mode. Cardiac ultrasound vector flow imaging is capable of measuring the actual magnitude and direction of the blood flow velocity, obtaining the quantitative parameters of hemodynamics, and then providing more information for clinical research and diagnosis. This study mainly reviewed several different vector flow imaging techniques for cardiac flow and presented the implementation difficulties, and proposed a diverging wave based high frame rate cardiac ultrasound vector flow imaging. The study discussed the limitation of current ultrasound technology used in the cardiac flow measurement, analyzed and demonstrated the specific reasons for these implementation difficulties and the potential future development.
Blood Flow Velocity ; Heart/physiology* ; Hemodynamics ; Ultrasonography

To study the blood flow parameters for 2 anatomical segments of posterior cerebral artery (PCA) in normal singleton fetal.
 Methods: The blood flow velocity parameters peak systolic velocity (PSV), end diastolic velocity (EDV), time-average maximum velocity (TAMAXV), velocity time integral (VTI) and resistance parameters systolic peak velocity and end diastolic velocity ratio (S/D), pulsatility index (PI), resistance index (RI) for 2 anatomical segments in PCA were recorded. The first segment of the PCA (PCAS1) was recorded between the origin of PCA and the proximal part of the posterior communicating artery. The second segment of the PCA (PCAS2) was recorded at the distal part of the posterior communicating artery. The blood parameters in both PCAS1 and PCAS2 were analyzed by using Pearson correlation and multiple curves fitting with gestational age (GA). Paired student's t test was performed to compare the difference in blood parameter between PCAS1 and PCAS2.
 Results: The blood flow velocity parameters in both PCAS1 and PCAS2 were increased with the GA (P<0.0001), with the best fitted curves of Quadratic curve (P<0.0001). There were no correlations between resistance parameters in PCA and GA (P>0.05). Resistance parameters in PCAS1 were higher than those in PCAS2 (P<0.05).
 Conclusion: The blood flow velocity parameters in both PCAS1 and PCAS2 are increased with GA. The resistance parameters in both PCAS1 and PCAS2 do not change with GA. Study on the velocities and resistance in these 3 arterial branches provides a more comprehensive evaluation on the process of brain circulation.
Blood Flow Velocity ; physiology ; Diastole ; physiology ; Female ; Gestational Age ; Hemodynamics ; physiology ; Humans ; Posterior Cerebral Artery ; physiology ; Pregnancy ; Systole ; physiology

By using Doppler sensor and pressure sensor, the cerebrovascular stroke detector can be used to measure the blood flow velocity and blood pressure of the carotid artery. In this study, a variety of signal conversion and isolation processing techniques are proposed for processing and feature extraction of the output signals from the sensors. Finally, effective signal output waveforms that can be used to evaluate the cerebrovascular hemodynamics index (CVHI) are obtained, and the sound signal outputs that can reflect the change characteristics of blood flow velocity and blood pressure signals are generated, which realizes the application functional requirements of the detector.
Blood Flow Velocity/physiology* ; Cerebrovascular Circulation/physiology* ; Hemodynamics/physiology* ; Humans ; Stroke ; Technology

As the operative mortality has diminished and the number of survivors has increased after Fontan procedure, morbidities related to the unnatural physiology of cavopulmonary flow have developed. One of the complications by the hemodynamic derangement after Fontan procedure is a protein-losing enteropathy. This is a rare but life-threatening complication after the Fontan operation. Treatment strategies are highly variable. But, reports on successful management are limited. We experienced three cases of protein-losing enteropathy after the Fontan operation. We report that the conversion to the total extracardiac or intracardiac cavopulmonary connection with fenestration is a satisfactory treatment modality for protein- losing enteropathy after the Fontan operation.
Fontan Procedure* ; Hemodynamics ; Humans ; Mortality ; Physiology ; Protein-Losing Enteropathies* ; Survivors

Hemodynamic monitoring is important for critically ill patients in emergency medicine. While the conventional static hemodynamic monitoring may not accurately reflect the hemodynamic status, functional hemodynamic monitoring can dynamicly and individually monitor the hemodynamic status, and thus becomes a valuable supplementation for conventional static hemodynamic monitoring. This article reviews the limitations of conventional hemodynamic monitoring and introduces the methodology of functional hemodynamic monitoring.
Emergency Medicine ; methods ; Hemodynamics ; physiology ; Humans ; Monitoring, Physiologic ; methods

Hepatic perfusion parameters play an important role in detecting and diagnosing diffusion diseases of liver. Based on a hemodynamic model. In this study, we described a fast and accurate method to calculate the perfusion parameters. First, we used a dual-input one-compartment kinetics model to illustrate the distribution of the contrast agent concentration among the body. Then, we used the Gaussian function to fit the scatter concentration data of portal vein and aorta, to obtain a liver agent concentration on function of time. Finally, we solved the model parameters by using Levenberg-Marquardt algorithm, and calculated the perfusion parameters. The results showed that the method proposed in this study could calculate the parameters precisely, and had a prosperous future application possibility.
Algorithms ; Contrast Media ; Hemodynamics ; Humans ; Liver ; physiology ; Models, Biological ; Perfusion

A model of fluid dynamics related to the myocardial bridginged and mural coronary artery was designed and manufactured according to the physical principle and characteristic of the mural coronary artery. The model can imitate systematically well the effect of myocardial bridging on hemodynamic change of the mural coronary artery under different controlled experimental parameter. The methodology is proved to be feasible and has good prosperity of experimental study.
Coronary Vessels ; physiology ; Hemodynamics ; Humans ; Models, Cardiovascular ; Myocardial Bridging

Calculation of cardiac hemodynamic parameters is based on accurate detection of feature points in impedance cardiogram. According to these parameters, doctors can determine heart conditions, so it is very important to accurately detect the feature point of impedance differential signals. This article presents a process in which we used wavelet threshold method to de-noise signals, and then detected the feature points after six layers wavelet decomposition by using bior3. 7. The experimental data were collected from healthy persons in our laboratory and twenty two clinical patients in Chongqing Daping Hospital by using KF_ICG instrument. The results indicated that this method could precisely detect feature points whether it was from healthy people or clinical patients. This helps to achieve the application of noninvasive detection cardiac hemodynamic parameters in clinical treatments by using impedance method.
Cardiography, Impedance ; Electric Impedance ; Heart ; physiology ; Hemodynamics ; Humans ; Wavelet Analysis

OBJECTIVETo study the effect of Simulated Microgravity and its Associated Mechanism on Pulmonary Circulation in Rats).

METHODSRat tail-suspension model was used to simulate the physiological effects of microgravity and changes in pulmonary blood vessel morphology, pulmonary arterial and venous blood pressure, pulmonary vascular resistance, pulmonary vasomotoricity, as well as the regulation of pulmonary circulation by cytokines produced and released by the lung of rats were measured.

RESULTSThe walls of pulmonary blood vessels of rats were thickened, and the pulmonary artery was reconstructed with increased pulmonary vascular resistance. The pulmonary blood vessels of rats became more prone to dilation as contractions increased. Rat epithelial Adrenomedulin gene transcription and protein expression were upregulated. The level of basic fibroblast growth Factor of rat was also elevated.

CONCLUSIONFindings from the present study on rats revealed that the microgravity can affect pulmonary blood vessel structure, pulmonary arterial pressure, and pulmonary blood vessel self-regulation and cytokine production.

Animals ; Hemodynamics ; Male ; Pulmonary Artery ; physiology ; Pulmonary Circulation ; physiology ; Rats ; Rats, Wistar ; Weightlessness

Microcirculatory dysfunction is an important pathophysiological change of shock. In the last decade, many researches on the mechanism of microcirculatory dysfunction have been involved in areas such as the glycocalyx damage of vascular endothelial cells, macrocirculation- microcirculation discoupling, vascular hyporeactivity, and microcirculation monitoring. Accordingly, this paper discussed how these research findings can be applied to burn patients, with the aim of alerting the clinicians to improving microcirculation, and maintaining hemodynamic coordination during the treatment of burn shock and burn septic shock. In addition, with the development of accurate and reliable microcirculation monitoring techniques, it is necessary to carry out multi-center clinical trials to reveal the clinical significance of target-oriented shock resuscitation protocol combining macrocirculatory and microcirculatory parameters.
Burns/therapy* ; Endothelial Cells ; Hemodynamics/physiology* ; Humans ; Microcirculation/physiology* ; Resuscitation ; Shock ; Shock, Septic/therapy*