Search results for "Pulsatile flow"
showing 10 items of 40 documents
Blood pressure and pulse wave velocity values in the institutionalized elderly aged 80 and over: baseline of the PARTAGE study.
2009
The aim of the longitudinal study PARTAGE (predictive values of blood pressure and arterial stiffness in institutionalized very aged population) was to determine the predictive value of blood pressure (BP) and arterial stiffness for overall mortality, major cardiovascular events and cognitive decline in a large population of institutionalized patients aged 80 and over. In the study herein, we present the baseline data values of this study.A total of 1130 patients were recruited (878 women), living in French and Italian nursing homes. Clinical and 3-day self-measurements of BP were conducted. Aortic and upper limb pulse wave velocity were obtained using a PulsePen tonometer.Of this populatio…
The carotid pulse check revisited: What if there is no pulse?
2000
This study was undertaken to evaluate the diagnostic accuracy and time required by first responders to assess the carotid pulse in potentially pulseless patients. We conducted a prospective, randomized study of first responders (n = 206; four different training levels) and were blinded as to the patients' conditions in the cardiac operating rooms of a university hospital. Sixteen patients underwent coronary artery bypass surgery on nonpulsatile cardiopulmonary bypasses. Carotid pulse check was performed either during pulsatile (spontaneous) or during nonpulsatile (extracorporeal) circulation. Patients' hemodynamic status at the time of assessment, diagnostic accuracy of the first responders…
Arterial stiffness, endothelial and cognitive function in subjects with type 2 diabetes in accordance with absence or presence of diabetic foot syndr…
2017
BACKGROUND: Endothelial dysfunction is an early marker of cardiovascular disease so endothelial and arterial stiffness indexes are good indicators of vascular health. We aimed to assess whether the presence of diabetic foot is associated with arterial stiffness and endothelial function impairment. METHODS: We studied 50 subjects with type 2 diabetes mellitus and diabetic foot syndrome (DFS) compared to 50 diabetic subjects without diabetic foot, and 53 patients without diabetes mellitus, by means of the mini mental state examination (MMSE) administered to evaluate cognitive performance. Carotid-femoral pulse wave velocity (PWV) and augmentation index (Aix) were also evaluated by Applanation…
Simultaneous recording of skin blood pulsations at different vascular depths by multiwavelength photoplethysmography.
2007
A new technique for parallel recording of reflection photoplethysmography (PPG) signals in a broad spectral band (violet to near-infrared) has been developed, and its potential for assessment of blood microcirculation at various depths from the skin surface is discussed. PPG signals have been simultaneously detected at cw laser wavelength sets comprising 405, 532, 645, 807, and 1064 nm. Various signal baseline responses to breath holding and different shapes of the PPG pulses originated from the same heartbeat but recorded at different wavelengths have been observed, indicating a depth variety of the skin blood pulsation dynamics.
Investigation of the hemodynamic flow conditions and blood-induced stresses inside an abdominal aortic aneurysm by means of a SPH numerical model.
2019
The estimation of blood flow-induced loads occurring on the artery wall is affected by uncertainties hidden in the complex interaction of the pulsatile flow, the mechanical parameters of the artery, and the external support conditions. To circumvent these difficulties, a specific tool is developed by combining the aorta displacements measured by an electrocardiogram-gated-computed tomography angiography, with the blood velocity field computed by a smoothed particle hydrodynamics (SPH) numerical model. In the present work, the SPH model has been specifically adapted to the solution of the 3D Navier-Stokes equations inside a domain with boundaries of prescribed motion. Images of the abdominal…
Is it possible to predict late antepartum stillbirth by means of cerebroplacental ratio and maternal characteristics?
2019
Objective: To examine the potential value of fetal ultrasound and maternal characteristics in the prediction of antepartum stillbirth after 32 weeks’ gestation. Methods: This was a retrospective multicenter study in Spain. In 29 pregnancies, umbilical artery pulsatility index (UA PI), middle cerebral artery pulsatility index (MCA PI), cerebroplacental ratio (CPR), estimated fetal weight (EFW), and maternal characteristics were recorded within 15 days prior to a stillbirth. The values of UA PI, MCA PI, and CPR were converted into multiples of the normal median (MoM) for gestational age and the EFW was expressed as percentile according to a Spanish reference range for gestational age. Data fr…
Novel Simulation Model with Pulsatile Flow System for Microvascular Training, Research, and Improving Patient Surgical Outcomes
2020
Background Simulation allows surgical trainees to acquire surgical skills in a safe environment. With the aim of reducing the use of animal experimentation, different alternative nonliving models have been pursued. However, one of the main disadvantages of these nonliving models has been the absence of arterial flow, pulsation, and the ability to integrate both during a procedure on a blood vessel. In the present report, we have introduced a microvascular surgery simulation training model that uses a fiscally responsible and replicable pulsatile flow system. Methods We connected 30 human placentas to a pulsatile flow system and used them to simulate aneurysm clipping and vascular anastomosi…
Relations of Metabolically Healthy and Unhealthy Obesity to Digital Vascular Function in Three Community‐Based Cohorts: A Meta‐Analysis
2017
Background Microvascular dysfunction is a marker of early vascular disease that predicts cardiovascular events. Whether metabolically healthy obese individuals have impaired microvascular function remains unclear. The aim of this study was to evaluate the relation of obesity phenotypes stratified by metabolic status to microvascular function. Methods and Results We meta‐analyzed aggregate data from 3 large cohorts (Brazilian Longitudinal Study of Adult Health, the Framingham Heart Study, and the Gutenberg Heart Study; n=16 830 participants, age range 19–90, 51.3% men). Regression slopes between cardiovascular risk factors and microvascular function, measured by peripheral arterial tonometr…
Application of colour magnification technique for revealing skin microcirculation changes under regional anaesthetic input
2013
In this work the colour magnification technique was applied for monitoring of palm skin microcirculation changes under peripheral (Plexus Brachialis with axiliary access) Regional Anaesthesia (RA). During the RA procedure 20 minute video of patient’s forearm was taken at steady light conditions. Video content was processed offline by custom developed Matlab software with build-in colour magnification algorithm that performs temporal filtering of video sequence near-heartbeat frequency, spatial decomposition of video and amplification of pulsatile signal in every pixel of skin image. Using this method, we are able to visualize the subcutaneous microcirculation changes in high spatial resolut…
Measuring Heart Rate with a Heat Flux Sensor
2021
Different wearable biosignal measurement applications require minimally obtrusive and highly sensitive sensors and methods of transducing the heart pulse into an electric signal. At the same time, the sensors should have minimal power consumption and preferably provide information about more than just the heart rate. In this study, a method employing a heat flux sensor for recording the pulsatile cardiac component of an arterial pulse waveform is presented. The output signals of a conventional photoplethysmography (PPG) sensor and a heat flux sensor were recorded and compared with one another. The results show that a heat flux sensor can be used for measurement of heart pulse, in addition t…