Abstract:
:The most widely implanted prosthetic valve is the mechanical bileaflet. Recent clinical experiences suggest that some designs are more prone to thromboembolic episodes than others. This study evaluated the hinge flow and near-field forward flow of the new St. Jude Medical Regent bileaflet mechanical heart valve. Laser Doppler velocimetry measurements were conducted within the hinge and near-field forward flow regions of the Regent valve. These pulsatile flow velocity measurements were animated in time to visualize the flow fields throughout the cardiac cycle. During forward flow, a recirculation region developed in the inflow pocket of the Regent hinge but was subsequently abolished by strong backflow during valve closure. Leakage velocities in the hinge region reached 0.72 m/s and Reynolds shear stresses reached 2,600 dyn/cm2. Velocities in the near-field region were highest in the lateral orifice jet, reaching 2.1 m/s. Small regions of separated flow were observed adjacent to the hinge region. Leaflet motion through the Regent hinge creates a washout pattern which restricts the persistence of stagnation zones in its hinge. Based upon the results of these studies, the hematological performance of the Regent series should be at least equivalent to the performance of the Standard series.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Ellis JT,Travis BR,Yoganathan APdoi
10.1114/1.297subject
Has Abstractpub_date
2000-05-01 00:00:00pages
524-32issue
5eissn
0090-6964issn
1573-9686journal_volume
28pub_type
杂志文章abstract::Traditionally, measurement of pulmonary O2 uptake uses mass balance of N2 to correct for differences between inspired and expired volume (V) due to temperature (T) and relative humidity (RH). Often during anesthesia, N2 balance cannot be invoked due to high inspired O2 fraction (FIO2) or nonsteady state conditions. Th...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1114/1.1312184
更新日期:2000-09-01 00:00:00
abstract::The bending stiffness of a phospholipid bilayer (Kc) was measured by forming thin bilayer cylinders (tethers) from giant phospholipid vesicles. Based on the balance of forces, the tether force was expected to be proportional to the square root of the membrane tension, with a constant of proportionality containing Kc. ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/BF02684228
更新日期:1996-09-01 00:00:00
abstract::Human stem cells hold significant potential for the treatment of various diseases. However, their use as a therapy is hampered because of limited understanding of the mechanisms by which they respond to environmental stimuli. Efforts to understand extracellular biophysical cues have demonstrated the critical roles of ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-2008-8
更新日期:2018-06-01 00:00:00
abstract::Cell migration paths of mammary epithelial cells (expressing different versions of the promigratory tyrosine kinase receptor Her2/Neu) were analyzed within a bimodal framework that is a generalization of the run-and-tumble description applicable to bacterial migration. The mammalian cell trajectories were segregated i...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-008-9592-y
更新日期:2009-01-01 00:00:00
abstract::The emerging field of micro-technology has opened up new possibilities for exploring cellular chemotaxis in real space and time, and at single cell resolution. Chemotactic cells sense and move in response to chemical gradients and play important roles in a number of physiological and pathological processes, including ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章,评审
doi:10.1007/s10439-011-0489-9
更新日期:2012-06-01 00:00:00
abstract::A major benefit of computational modeling in biomechanics research is its ability to estimate internal muscular demands given limited input information. However, several assumptions regarding model parameters and constraints may influence model outputs. This research evaluated the influence of model parameter variabil...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-014-1035-3
更新日期:2014-09-01 00:00:00
abstract::While virtual reality (VR) has potential in enhancing cardiovascular diagnosis and treatment, prerequisite labor-intensive image segmentation remains an obstacle for seamlessly simulating 4-dimensional (4-D, 3-D + time) imaging data in an immersive, physiological VR environment. We applied deformable image registratio...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-02113-z
更新日期:2018-12-01 00:00:00
abstract::Optoelectronic plethysmography (OEP) is a noninvasive method for assessing lung volume variations and the contributions of different anatomical compartments of the chest wall (CW) through measurements of the motion of markers attached to the CW surface. The present study proposes a new method for analyzing the local C...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-017-1840-6
更新日期:2017-08-01 00:00:00
abstract::This project was undertaken to establish if the integral circulation had any effects upon the mechanical behavior of bone. The influence of blood flow in the rabbit tibia on the strain induced at the bone surface when under load was assessed. Recordings were taken from three adult and three immature New Zealand White ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/BF02390377
更新日期:1994-03-01 00:00:00
abstract::In an effort to share best practices in undergraduate engineering design education, we describe the origin, evolution and the current status of the undergraduate biomedical engineering design team program at Johns Hopkins University. Specifically, we describe the program and judge the quality of the pedagogy by relati...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-013-0781-y
更新日期:2013-09-01 00:00:00
abstract::During defecation, solid, semisolid or liquid stools are eliminated via the anus in a complex physiological process. Up to 25% of the population are affected by anorectal disorders that are poorly recognized and treated. We developed a new bionics device, a simulated stool named Fecobionics, to replace several current...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-02149-1
更新日期:2019-02-01 00:00:00
abstract::Soft collagenous tissue features many hierarchies of structure, starting from tropocollagen molecules that form fibrils, and proceeding to a bundle of fibrils that form fibers. Here we report the development of an atomistically informed continuum model of collagenous tissue. Results from full atomistic and molecular m...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-009-9679-0
更新日期:2009-06-01 00:00:00
abstract::There is a high incidence of low back pain (LBP) associated with occupations requiring sustained and/or repetitive lumbar flexion (SLF and RLF, respectively), which cause creep of the viscoelastic tissues. The purpose of this study was to determine the effect of creep on lumbar biomechanics and facet joint capsule (FJ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-005-1742-x
更新日期:2005-03-01 00:00:00
abstract::This article presents a multi-scale computational model describing the transport of water vapor and heat within the human conducting airways and its interaction with cellular fluid transport kinetics. This tight coupling between the cell and the evaporative flux allows the periciliary liquid (PCL) depth to be investig...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-0111-6
更新日期:2010-12-01 00:00:00
abstract::Adherence of a biological graft to the wound surface is the most important factor influencing the ultimate success of graft viability. A machine has been developed to test the adherence of biological graft materials to a substrate such as a wound surface. The peeling mode, which yields reproducible quantitative measur...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/BF02368164
更新日期:1993-01-01 00:00:00
abstract::Pressure ulcer risk assessment might be optimized by incorporating the soft tissue reaction to mechanical loading in the currently used risk assessment scales. Cytokines, like IL-1alpha, IL-1RA, IL-8, and TNF-alpha, might be used to determine this tissue reaction, since they are released after 24 h of mechanical loadi...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-009-9652-y
更新日期:2009-05-01 00:00:00
abstract::This work presents a novel methodology for building a three-dimensional patient-specific eyeball model suitable for performing a fully automatic finite element (FE) analysis of the corneal biomechanics. The reconstruction algorithm fits and smooths the patient's corneal surfaces obtained in clinic with corneal topogra...
journal_title:Annals of biomedical engineering
pub_type: 临床试验,杂志文章
doi:10.1007/s10439-015-1426-0
更新日期:2016-05-01 00:00:00
abstract::Registration of bone structures is a common problem in medical research as well as in clinical applications. Intrasubject rigid 3D monomodality registration of segmented bone structures of CT images and multimodality registration of muMR and segmented muCT bone images were performed with the multiresolution intensity-...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-9981-x
更新日期:2010-07-01 00:00:00
abstract::Effects of hyperthermia on transport of low-density lipoprotein (LDL) through a stenosed arterial wall are analyzed comprehensively in the present work. The realistic and pertinent aspects of an arterial wall is represented by a multi-layer model, with a proper representation of the thickened intima region due to the ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-014-1196-0
更新日期:2015-07-01 00:00:00
abstract::Newborns with single ventricle physiology are usually palliated with a multi-staged procedure. When cardiovascular complications e.g., collateral vessel formation occur during the inter-stage periods, further treatments are required. An 8-month-old patient, who underwent second stage (i.e., bi-directional Glenn, BDG) ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-014-1113-6
更新日期:2015-06-01 00:00:00
abstract::The pia-arachnoid complex (PAC) covering the brain plays an important role in the mechanical response of the brain during impact or inertial loading. Recent studies have revealed the complicated material behavior of the PAC. In this study, the nonlinear viscoelastic, transversely isotropic material properties of the P...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-013-0948-6
更新日期:2014-04-01 00:00:00
abstract::Potential human and environmental hazards resulting from the exposure of living organisms to silver nanoparticles (Ag NPs) have been the subject of intensive discussion in the last decade. Despite the growing use of Ag NPs in biomedical applications, a quantification of the toxic effects as a function of the total sil...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-020-02449-5
更新日期:2020-04-01 00:00:00
abstract::3D bioprinting technology is a promising approach for corneal stromal tissue regeneration. In this study, gelatin methacrylate (GelMA) mixed with corneal stromal cells was used as a bioink. The visible light-based stereolithography (SLA) 3D bioprinting method was utilized to print the anatomically similar dome-shaped ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-020-02537-6
更新日期:2020-07-01 00:00:00
abstract::High mechanical stress in atherosclerotic plaques at vulnerable sites, called critical stress, contributes to plaque rupture. The site of minimum fibrous cap (FC) thickness (FC(MIN)) and plaque shoulder are well-documented vulnerable sites. The inherent weakness of the FC material at the thinnest point increases the s...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-0078-3
更新日期:2010-10-01 00:00:00
abstract::The bioinspired, microscale tissue engineering approach has emerged in recent years as a promising alternative to preformed scaffolds. Using this approach, complex tissues and organs can be efficiently engineered from microscale modules to replicate the intricate architecture and physiology of vascularized organs and ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-02192-y
更新日期:2019-05-01 00:00:00
abstract::Current efforts to evaluate the performance of laparoscopic arterial fusion devices are limited to costly, time consuming, empirical studies. Thus, a finite element (FE) model, with the ability to predict device performance would improve device design and reduce development time and costs. This study introduces a mode...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-016-1588-4
更新日期:2016-11-01 00:00:00
abstract::A vaccine that induces broadly neutralizing antibodies (bnAbs) against the human immunodeficiency virus (HIV) would be instrumental in controlling the disease. The membrane proximal external region (MPER) peptide is an appealing antigen candidate since it is conserved and is the target of several human bnAbs, such as ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-019-02398-8
更新日期:2020-07-01 00:00:00
abstract::Wiener static nonlinear system identification was used to study the linear dynamics and static nonlinearities in the response of skin and underlying tissue under indentation in vivo. A device capable of measuring the dynamic mechanical properties of bulk skin tissue was developed and it incorporates a custom-built Lor...
journal_title:Annals of biomedical engineering
pub_type: 临床试验,杂志文章
doi:10.1007/s10439-012-0580-x
更新日期:2012-10-01 00:00:00
abstract::Diabetic retinopathy is the leading cause of blindness in working age individuals in the United States. Breakdown of the blood-retinal barrier is one of the earliest events in the progression of diabetic retinopathy. Ideally, therapeutic measures would be directed at this early stage, but there are few sensitive, quan...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1114/1.1385809
更新日期:2001-08-01 00:00:00
abstract::Based on mathematical expressions governing the electric field, the extracellular potentials generated by a single active fiber in a restricted circular cylindrical volume conductor are evaluated. This paper examines the effect of the extent of the volume conductor, with radius b, on the extracellular potentials at di...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/BF02368439
更新日期:1990-01-01 00:00:00