The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Uterine artery Doppler waveforms are often studied to determine whether a patient is at risk of developing pathologies such as pre‐eclampsia. Many uterine waveform indices have been developed, which attempt to relate characteristics of the waveform with the physiological adaptation of the maternal cardiovascular system, and are often suggested to be an indicator of increased placenta resistance and...
Recent advances in the development of noninvasive cardiac imaging technologies have made it possible to measure longitudinal and circumferential strains at a high spatial resolution also at intramural level. Local mechanical activation times derived from these strains can be used as noninvasive estimates of electrical activation, in order to determine, eg, the origin of premature ectopic beats during...
We construct an idealized computational model of the left human heart for the study of the blood flow dynamics in the left atrium and ventricle. We solve the Navier‐Stokes equations in the ALE formulation and we prescribe the left heart wall displacement based on physiological data; moreover, we consider the presence of both the mitral and aortic valves through the resistive method. We simulate the...
Model‐based prediction of fractional flow reserve (FFR) in the context of stable coronary artery disease (CAD) diagnosis requires a number of modelling assumptions. One of these assumptions is the definition of a baseline coronary flow, ie, total coronary flow at rest prior to the administration of drugs needed to perform invasive measurements. Here we explore the impact of several methods available...
Mathematical modelling and numerical simulation in cardiac electrophysiology have already been studied extensively. However, there is a clear lack of techniques and methodologies for studying the propagation of action potential in a heart with structural defects. In this article, we present a modified version of the bidomain model, derived using homogenisation techniques with the assumption of existence...
Aortic cross‐clamping is a common strategy during vascular surgery, however, its instantaneous impact on hemodynamics is unknown. We, therefore, developed two numerical models to estimate the immediate impact of aortic clamping on the vascular properties. To assess the validity of the models, we recorded continuous invasive pressure signals during abdominal aneurysm repair surgery, immediately before...
State‐of‐the‐art distributed‐memory computer clusters contain multicore CPUs with 16 and more cores. The second generation of the Intel Xeon Phi many‐core processor has more than 60 cores with 16 GB of high‐performance on‐chip memory. We contrast the performance of the second‐generation Intel Xeon Phi, code‐named Knights Landing (KNL), with 68 computational cores to the latest multicore CPU Intel...
The angle of arterial tapering increases with ageing, and the geometrical changes of the aorta may cause an increase in central arterial pressure and stiffness. The impact of tapering has been primarily studied using frequency‐domain transmission line theories. In this work, we revisit the problem of tapering and investigate its effect on blood pressure and pulse wave velocity (PWV) using a time‐domain...
This study develops a computational model of the braided stent for interpreting the mechanism of stent flattening during deployment into curved arteries. Stent wires are expressed using Kirchhoff's rod theory and their mechanical behavior is treated using a corotational beam formulation. The equation of motion of the braided stent is solved in a step‐by‐step manner using the resultant elastic force...
Performance of the locking compression plate (LCP) is a multifactorial function. The control parameters of plating, such as geometries, material properties, and physical constraints of the LCP components, affect basic functions associated with the bone fixation, including the extent of stress shielding and subsequent bone remodeling, strength and stability of the bone‐LCP construct, and performance...
We use computational fluid dynamics (CFD) to simulate blood flow in intracranial aneurysms (IAs). Despite ongoing improvements in the accuracy and efficiency of body‐fitted CFD solvers, generation of a high quality mesh appears as the bottleneck of the flow simulation and strongly affects the accuracy of the numerical solution. To overcome this drawback, we use an immersed boundary method. The proposed...
We report a novel mathematical model of an artificial auditory system consisting of a micro‐machined cochlea and the auditory nerve response it evokes. The modeled micro‐machined cochlea is one previously realized experimentally by mimicking functions of the cochlea [Shintaku et al, Sens. Actuat. 158 (2010) 183–192; Inaoka et al, Proc. Natl. Acad. Sci. USA 108 (2011) 18390–18395]. First, from the...
The contraction of the human heart is a complex process as a consequence of the interaction of internal and external forces. In current clinical routine, the resulting deformation can be imaged during an entire heart beat. However, the active tension development cannot be measured in vivo but may provide valuable diagnostic information. In this work, we present a novel numerical method for solving...
Recent experimental observations have shown evidence of an unexpected sudden drop‐off in the dense core vesicles (DCVs) content at the ends of certain types of axon endings. This article seeks to determine whether these observations may be explained without modifying the parameters characterizing the ability of distal en passant boutons to capture and accumulate DCVs. We developed a mathematical model...
The cover image is based on the Special Issue Article Uncertainty quantification in subject‐specific estimation of local vessel mechanical properties by Bruno V. Rego et al., https://doi.org/10.1002/cnm.3535.
Quantitative estimation of local mechanical properties remains critically important in the ongoing effort to elucidate how blood vessels establish, maintain, or lose mechanical homeostasis. Recent advances based on panoramic digital image correlation (pDIC) have made high‐fidelity 3D reconstructions of small‐animal (e.g., murine) vessels possible when imaged in a variety of quasi‐statically loaded...
Patients with pulsatile tinnitus (PT) have unstable treatment effects after resurfacing surgery. Flow‐diverting stents (FDS) are proposed as a potential method for the treatment of PT, but the therapeutic effect is not clear. This study aimed to investigate the efficacy of FDS in the treatment of patients with PT induced by sigmoid sinus diverticulum (SSD) and sigmoid sinus wall dehiscence (SSWD)...
Endovascular aortic repair (EVAR) has become the preferred intervention option for aortic aneurysms and dissections. This is because EVAR is much less invasive than the alternative open surgery repair. While in‐hospital mortality rates are smaller for EVAR than open repair (1%–2% vs. 3%–5%), the early benefits of EVAR are lost after 3 years due to larger rates of complications in the EVAR group. Clinicians...