Abstract:
:A computational fluid dynamics model for the analysis of the bileaflet mechanical heart valve closure process is presented. The objective of the study is to demonstrate the ability of the numerical model to simulate the leaflet motion during the closing phase in order to investigate the closure fluid dynamics and to evaluate the effect of alterations in the leaflet tip geometry. The model has been applied to six different combinations of the leaflet tip geometry and the gap width between the leaflet tip and the housing. The results show that the negative pressure quickly develops on the atrial side of the leaflet tip. The pressure becomes more negative as the leaflet closure progresses and the lowest pressure is reached before the leaflet comes to a stop in the closed position. The flow dynamics at the instant of valve closure is strongly dependent on the leaflet velocity during the closing phase. Decrease of the tip velocity by a factor of three in the last four degrees of leaflet motion leads to a 50% reduction in the negative pressure magnitude.
journal_name
J Biomechjournal_title
Journal of biomechanicsauthors
Lai YG,Chandran KB,Lemmon Jdoi
10.1016/s0021-9290(02)00056-8keywords:
subject
Has Abstractpub_date
2002-07-01 00:00:00pages
881-92issue
7eissn
0021-9290issn
1873-2380pii
S0021929002000568journal_volume
35pub_type
杂志文章abstract::The swimming process by which mammal spermatozoa progress towards an egg within the reproductive organs is important in achieving successful internal fertilization. The viscosity of oviductal mucus is more than two orders of magnitude greater than that of water, and oviductal mucus also has non-Newtonian properties. I...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2015.08.005
更新日期:2015-09-18 00:00:00
abstract::In label-free biodetections based on microcantilever technology, double-stranded DNA (dsDNA) structures form through the linkage between probe single-stranded DNA (ssDNA) molecules immobilized on solid substrates and target ssDNA molecules in solutions. Mechanical/electrical properties of these biolayers are important...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2009.03.050
更新日期:2009-07-22 00:00:00
abstract::The study was designed to examine the effects of partial fatigue on specific mechanical parameters which characterise human tendons in vitro. Specimens prepared from 12 intact Extensor digitorum longus tendons of the foot were subjected to partial fatigue, equivalent to 25% of the median fatigue life, by a cyclic squa...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/s0021-9290(01)00177-4
更新日期:2002-03-01 00:00:00
abstract::Previous epidemiological studies indicate that the use of thumb-push mechanical pipettes is associated with musculoskeletal disorders (MSDs) in the hand. The goal of the current study was to analyze the loading in the muscle-tendon units in the thumb during pipetting. The hand is modeled as a multi-body linkage system...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2013.11.015
更新日期:2014-01-22 00:00:00
abstract::Identification of the localized mechanical response of the plantar soft tissue pads underneath the metatarsal heads (i.e., sub-MTH pad) to external loading is key to understand and predict how it functions in a gait cycle. The mechanical response depends on various parameters, such as the external load (direction and ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2011.03.031
更新日期:2011-06-03 00:00:00
abstract::As a hybrid between a hypodermic needle and transdermal patch, we have used microfabrication technology to make arrays of micron-scale needles that transport drugs and other compounds across the skin without causing pain. However, not all microneedle geometries are able to insert into skin at reasonable forces and wit...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2003.12.010
更新日期:2004-08-01 00:00:00
abstract::Wall shear stress distribution in the carotid siphon, which is a multiple curved segment of the internal carotid artery, is investigated numerically under physiological flow conditions. The computer simulation of flow through the model segment is based on the time-dependent, three-dimensional Navier-Stokes equations, ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/0021-9290(88)90203-5
更新日期:1988-01-01 00:00:00
abstract::Although biomechanical studies of the normal rat vein wall have been reported (Weizsacker, 1988; Plante, 2002), there are no published studies that have investigated the mechanical effects of thrombus formation on murine venous tissue. In response to the lack of knowledge concerning the mechanical consequences of thro...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2010.07.012
更新日期:2010-11-16 00:00:00
abstract::Essential tremor (ET) is a common tremor disorder affecting postural/action tremor of the upper extremities and midline. Recent research revealed a cerebellar-like deficit during tandem gait in persons with ET, though spatiotemporal variability during normal gait in ET has been relatively ignored. The first purpose of...
journal_title:Journal of biomechanics
pub_type: 临床试验,杂志文章
doi:10.1016/j.jbiomech.2013.07.039
更新日期:2013-10-18 00:00:00
abstract::The damping mechanisms that are operational in the heel pad during the impact phase of locomotion have the important function to protect the musculo-skeletal system from injuries. How this is achieved is still not fully understood, as is for instance illustrated by the 'heel pad paradox', the observation that in vivo ...
journal_title:Journal of biomechanics
pub_type: 临床试验,杂志文章
doi:10.1016/j.jbiomech.2004.10.006
更新日期:2005-12-01 00:00:00
abstract::Mucosal folding in such biological vessels as esophagus and airway is essential to their physiological functions and can be affected by some diseases, e.g., inflammation, edema, lymphoma, and asthma. A biomechanical model within the framework of finite deformation theory is proposed to address the mucosal folding indu...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2010.09.007
更新日期:2011-01-04 00:00:00
abstract::Quantification of baseball hitting mechanics under game conditions help players to become successful batters and prevent injuries. Inertial measurement units (IMUs) can measure motion without any spatial restriction and are thus becoming a popular tool to investigate sports biomechanics. Biomechanical analysis of hitt...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2019.02.001
更新日期:2019-04-18 00:00:00
abstract::Factors were examined which altered the propagation of aortic dissections in canine aortas. Thoracic aortas were removed from sacrificed dogs from the distal end of the arch to the diaphragm. An intimal tear was created at the proximal end of the aorta. The dissection was propagated using a pulsatile pressure system w...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/0021-9290(87)90268-5
更新日期:1987-01-01 00:00:00
abstract::The analysis of in-field biomechanics data typically requires the identification of foot contact. Existing techniques to identify foot contact using accelerometers offer a viable option for identifying foot contact in the field. However, these techniques often require the placement of additional accelerometers or the ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2020.109768
更新日期:2020-05-22 00:00:00
abstract::Sudden heart attacks remain one of the primary causes of premature death in the developed world. Asymptomatic vulnerable plaques that rupture are believed to prompt such fatal heart attacks and strokes. The role of microcalcifications in the vulnerable plaque rupture mechanics is still debated. Recent studies suggest ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2007.11.029
更新日期:2008-01-01 00:00:00
abstract::Simulating and analysing eye movement is useful for assessing visual system contribution to discomfort with respect to body movements, especially in virtual environments where simulation sickness might occur. It can also be used in the design of eye prosthesis or humanoid robot eye. In this paper, we present two biome...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2018.02.006
更新日期:2018-04-11 00:00:00
abstract::This study was mainly performed to investigate the effects of high maxillary expansion forces on the skull with fresh and thiel-fixed human skulls. The maxillary suture was not weakened except in one experiment. This study compares the strain measured on the zygomatic process of the skull with the results of a finite ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2010.02.002
更新日期:2010-05-07 00:00:00
abstract::There is a growing body of evidence that the step-to-step variations present in human walking are related to the biomechanics of the locomotive system. However, we still have limited understanding of what biomechanical variables influence the observed nonlinear gait variations. It is necessary to develop reliable mode...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2008.01.007
更新日期:2008-01-01 00:00:00
abstract::Quantifying angular joint kinematics of the upper body is a useful method for assessing upper limb function. Joint angles are commonly obtained via motion capture, tracking markers placed on anatomical landmarks. This method is associated with limitations including administrative burden, soft tissue artifacts, and int...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2018.02.028
更新日期:2018-04-27 00:00:00
abstract::Evaluation of anterior laxity of the ankle joint complex is a difficult clinical problem. Currently, the prime determinant for anterolateral ligament function is the subjective manual examination of anterior laxity of the ankle joint complex. An instrumented dynamic test was developed for objective measurement of ante...
journal_title:Journal of biomechanics
pub_type: 临床试验,杂志文章
doi:10.1016/s0021-9290(02)00189-6
更新日期:2002-12-01 00:00:00
abstract::Two questions were addressed in this study: (1) how much strain of the superficial aponeurosis of the human medial gastrocnemius muscle (MG) was obtained during voluntary isometric contractions in vivo, (2) whether there existed inhomogeneity of the strain along the superficial aponeurosis. Seven male subjects, whose ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/s0021-9290(01)00196-8
更新日期:2002-02-01 00:00:00
abstract::Hamstring muscle strain injury is one of the most common injuries in sports involving sprinting and kicking. Studies examining hamstring kinematics and activations are rich for sprinting but lacking for kicking. The purpose of this study was to examine kinematics and activations of hamstring muscles in instep and cut-...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2019.109482
更新日期:2020-01-23 00:00:00
abstract::The tibia from six-week old chickens that develop idiopathic scoliosis were studied with stress relaxation experiments and torsional strength testing. Most parameters observed did not show any significant differences between tibias obtained from chickens with scoliosis and tibias from the control birds; however, the r...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/0021-9290(83)90046-5
更新日期:1983-01-01 00:00:00
abstract::We investigated the microstructural basis of a reduced stress concentration around the primary nutrient foramen of the equine third metacarpus. We quantified the spatial variations of compositional parameters (mineral content, volume fraction, histological architecture, and osteonal trajectories) from microradiographs...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/s0021-9290(03)00130-1
更新日期:2003-10-01 00:00:00
abstract::The goal of this study is to elucidate whether mechanobiological factors, including mechanical loading patterns, presence of bone graft, and proximity to the periosteum, correlate to de novo tissue generation and healing in critical sized long bone defects, which are enveloped by periosteum in situ and are bridged at ...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2010.06.026
更新日期:2010-10-19 00:00:00
abstract::The drop vertical jump (DVJ) task is commonly used to assess biomechanical performance measures that are associated with ACL injury risk in athletes. Previous investigations have solely assessed the first landing phase. We examined the first and second landings of a DVJ for differences in the magnitude of vertical gro...
journal_title:Journal of biomechanics
pub_type: 临床试验,杂志文章
doi:10.1016/j.jbiomech.2013.02.024
更新日期:2013-04-26 00:00:00
abstract::The unsteady flow through a model of the human nasal cavity is analyzed at a Strouhal number of Sr=0.791 for the complete respiration cycle. A comparison of the essential flow structures in the model geometry and a real nasal cavity shows the relevance of the model data. The analysis of the steady and unsteady solutio...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2009.12.008
更新日期:2010-04-19 00:00:00
abstract::The optimal sterilization method for load bearing allografts remains a clinical concern. Recently, supercritical carbon dioxide (SCCO2) treatments have been shown to be capable of terminally sterilizing a range of bacteria and viruses, while preserving the static mechanical properties of cortical bone. This study eval...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2013.04.006
更新日期:2013-06-21 00:00:00
abstract::Despite the paramount function of the thumb in daily life, thumb biomechanical models have been little developed and studied. Moreover, only two studies provided quantitative anthropometric data of tendon moment arms. To investigate thumb tendon tensions, biomechanicians and clinicians have to know the performances an...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2009.03.052
更新日期:2009-08-07 00:00:00
abstract::Movement variability has become an important field of research and has been studied to gain a better understanding of the neuro-muscular control of human movements. In addition to studies investigating "amplitude variability" there are a growing number of studies assessing the "temporal variability" in movements by ap...
journal_title:Journal of biomechanics
pub_type: 杂志文章
doi:10.1016/j.jbiomech.2012.02.008
更新日期:2012-04-30 00:00:00