Abstract：
:We present a comparison of the flow characteristics in an idealized smooth trachea model and a second model which has a roughness simulating cartilaginous rings. We use refractive index-matched particle image velocimetry (PIV) to measure the velocity field in a two-generation model of the trachea and main bronchi. The flow rate has a trachea-based Reynolds number Re=2800, which is comparable to a resting state. Our results show considerable differences between both cases, the most important of which is the size and magnitude of recirculation zones at the inlet of both bronchi. The smooth case shows a larger separation bubble at the bronchi entrance, which may retain aerosols and have different effects on particles of different sizes. Furthermore, the smooth case displays a higher vorticity along the bottom walls of the bronchi, while a higher vorticity is seen along the trachea walls in the ׳ringed׳ model. These findings suggest that modeling the trachea and main bronchi as smooth tubes may not be justified, since the flow conditions in lower generations will be affected by these differences.
journal_name
J Biomechjournal_title
Journal of biomechanicsauthors
Bocanegra Evans H,Castillo Ldoi
10.1016/j.jbiomech.2016.03.043subject
Has Abstractpub_date
2016-06-14 00:00:00pages
1601-1606issue
9eissn
0021-9290issn
1873-2380pii
S0021-9290(16)30385-2journal_volume
49pub_type
杂志文章abstract：:Due to increased atherosclerosis-caused mortality, identification of its genesis and development is of great importance. Although, key factors of the origin of the disease is still unknown, it is widely believed that cholesterol particle penetration and accumulation in arterial wall is mainly responsible for further w...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2017.11.029
更新日期：2018-01-23 00:00:00
abstract：:Although micromechanical finite-element models are being increasingly used to help interpret the results of bio-mechanical tests, there has not yet been a systematic study of the numerical errors and uncertainties that occur with these methods. In this work, finite-element models of human L1 vertebra have been used to...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/s0021-9290(98)00108-0
更新日期：1998-10-01 00:00:00
abstract：:The purpose of this study was to provide a quantitative description of residual femur motion within the socket during gait and to explore the relationship between residual femur motion and patient-reported comfort and function. It was hypothesized that increased residual bone movement would correlate to worse patient-...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2020.110050
更新日期：2020-11-09 00:00:00
abstract：:Multiple osteochondral grafts can be used to resurface large joint defects in both humans and horses. In humans, immediate postoperative weight bearing can be prevented, however in the equine, it is unavoidable. Early weight bearing can create detrimental graft micromotion. The aim of this study was to investigate the...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2005.10.007
更新日期：2006-01-01 00:00:00
abstract：:A reflection ultrasonic technique, which offers several advantages over transmission ultrasonic techniques, has been described for elastic property measurement of bone. Ultrasonic velocities from specimens of cancellous bone were compared using a reflection ultrasound technique and the more traditional transmission ul...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(94)90061-2
更新日期：1994-09-01 00:00:00
abstract：:Measures of local dynamic stability, such as the local divergence exponent (lambda*(s)) quantify how quickly small perturbations deviate from an attractor that defines the motion. When the governing equations of motion are unknown, an attractor can be reconstructed by defining an appropriate state space. However, stat...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2009.03.015
更新日期：2009-06-19 00:00:00
abstract：:We evaluated whether lumped-parameter non-linear viscoelastic models of human fingertip tissue can describe fingertip force-displacement characteristics during a range of rapid, dynamic tapping tasks. Eight human subjects tapped with their index finger on the surface of a rigid load cell while an optical system tracke...
journal_title：Journal of biomechanics
pub_type： 临床试验,杂志文章
doi：10.1016/s0021-9290(02)00438-4
更新日期：2003-04-01 00:00:00
abstract：:It is well known that cyclic mechanical loading can produce an anabolic response in bone. In vivo studies have shown that the insertion of short-term recovery periods (10-15 s) into mechanical loading profiles led to an increased osteogenic response compared to continuous cyclic loading of bone. Although this is sugge...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2004.08.009
更新日期：2005-09-01 00:00:00
abstract：:Cross-linked polyethylene foam (Plastazote) has been used in the management of painful foot disorders occurring in a number of disease processes. A series of mechanical tests have been performed under varying clinically encountered conditions to show a relationship between the deformation of the material and the load ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(84)90101-5
更新日期：1984-01-01 00:00:00
abstract：:A new approach for the assessment of gait patterns is presented. The use of neural network techniques for decision making in gait analysis is for some purposes more effective than biomechanical methods or conventional statistics. To demonstrate this, a neural network was trained to distinguish 'healthy' from 'patholog...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(93)90028-d
更新日期：1993-06-01 00:00:00
abstract：:Osteocytes actively regulate bone modeling and remodeling, direct skeletal mineralization, and regulate calcium/phosphate homeostasis and extracellular matrix metabolism; yet the specific role of osteocytes in maintaining bone structural integrity and strength is unknown. Studies have shown that the density of osteocy...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2008.01.017
更新日期：2008-01-01 00:00:00
abstract：:The peroneus longus (PL) is a rearfoot evertor, important in frontal plane foot motion. Studying PL function has been limited by previous electromyography (EMG) studies reporting poor between-day reliability. Due to its close proximity to adjacent muscles, EMG measures of PL may be susceptible to crosstalk, thus corre...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2019.01.037
更新日期：2019-03-27 00:00:00
abstract：:Humans control their movements using adaptive proprioceptive feedback from muscle afferents. The interaction between proprioceptive reflexes and biomechanical properties of the limb is essential in understanding the etiology of movement disorders. A non-linear neuromuscular model of the wrist incorporating muscle dyna...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2011.09.024
更新日期：2012-01-03 00:00:00
abstract：:Meaningful testing of stab resistant body armour requires the use of realistic body tissue simulants. A device for the determination of the force-displacement behaviour of materials in high impact loading situations has been developed for the testing of such simulants. Force measurement is achieved with the use of ele...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/s0021-9290(99)00191-8
更新日期：2000-03-01 00:00:00
abstract：:In this paper the mechanical response of soft collagenous tissues with regular fiber arrangement (RSCTs) is described by means of a nanoscale model and a two-step micro-macro homogenization technique. The non-linear collagen constitutive behavior is modeled at the nanoscale by a novel approach accounting for entropic ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2009.07.040
更新日期：2010-01-19 00:00:00
abstract：:Bone remodelling is a dynamic process that requires the coordinated interaction of osteocytes, osteoblasts, and osteoclasts, collaborating in basic multicellular units (BMUs). Communication between these cells can be by extracellular soluble molecules as well as directly propagating intercellular signalling molecules....
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2007.02.015
更新日期：2007-01-01 00:00:00
abstract：:The arteriovenous junction is characterised by high flow rates, large pressure difference and typically a palpable thrill or audible bruit, associated with turbulent flow. However, the arteriovenous junction is frequently studied with the assumption of streamline flow. This assumption is based on the Reynolds number c...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.07.038
更新日期：2015-10-15 00:00:00
abstract：:The purpose of this investigation was to develop a method to quantify a range of motion of the ankle joint complex (AJC) in vivo. A six-degree-of-freedom apparatus was constructed to measure the unconstrained active range of motion of the AJC. Extensive tests evaluating the accuracy of the fixture and data collection ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(93)90614-k
更新日期：1993-01-01 00:00:00
abstract：:Continuum finite element (FE) models of bones have become a standard pre-clinical tool to estimate bone strength. These models are usually based on clinical CT scans and material properties assigned are chosen as isotropic based only on the density distribution. It has been shown, however, that trabecular bone elastic...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2013.07.042
更新日期：2013-09-27 00:00:00
abstract：:Animal models of ventricular tachypacing (VTP) have been successfully used to reproduce the relevant features observed in patients with atrial fibrillation, such as increased atrial pressure and volume, ion-channel alterations and fibrosis. After performing VTP on a healthy Yorkshire pig, we measured an increase in vo...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2011.09.003
更新日期：2011-11-10 00:00:00
abstract：:This paper addresses the question of whether maximal vertical jump height depends on initial jumping posture. A direct dynamics computer simulation approach was used to avoid subject preference and practice effects. The human body was modeled as four rigid segments connected by ideal hinge joints, with movement constr...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(96)00030-9
更新日期：1996-09-01 00:00:00
abstract：:Understanding the mechanisms of instability can aid in reducing fall risk. As a sensitive measure of fall risk, the distance between the center of pressure (COP) and center of mass (COM) is currently assessed through discrete points assumed to represent physiological important fall mechanisms. However, it is unclear i...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2020.109899
更新日期：2020-07-17 00:00:00
abstract：:The carpometacarpal (CMC) joints of the hand facilitate motion of the metacarpals and are critical for functional tasks, especially tasks involving precision grasping. Despite their importance, only limited data describing metacarpal kinematics exist. In this short communication, we quantified in vivo metacarpal kinem...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2013.05.019
更新日期：2013-08-09 00:00:00
abstract：:Propulsive forces generated by swimmers hand/forearm, have been studied through experimental tests. However, there are serious doubts as to whether forces quantified in this way are accurate enough to be meaningful. In order to solve some experimental problems, some numerical techniques have been proposed using Comput...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2005.03.012
更新日期：2006-01-01 00:00:00
abstract：:The advent of microelectromechanical systems (MEMS) sensors has enabled real-time wall shear stress (WSS) measurements with high spatial and temporal resolution in a 3-D bifurcation model. To optimize intravascular shear stress assessment, we evaluated the feasibility of catheter/coaxial wire-based MEMS sensors in the...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2009.04.021
更新日期：2009-07-22 00:00:00
abstract：:The objective of this study was to determine the intervertebral kinematics of the young, healthy cervical spine during dynamic, three-dimensional, functional loading. Intervertebral motion was characterized by the range of motion (ROM) and the helical axis of motion (HAM). Biplane radiographs of the cervical spine wer...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.02.049
更新日期：2015-05-01 00:00:00
abstract：:Sitting is often assumed to involve high loads on the spine as well as on implants for stabilising the spine. Loads on internal spinal fixation devices were therefore measured in ten patients sitting on several types of seats, including a stool, a stool with a padded wedge, a chair, a physiotherapy ball, a knee-stool,...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/s0021-9290(01)00073-2
更新日期：2001-08-01 00:00:00
abstract：:Fatigue-related glenohumeral and scapulothoracic kinematic relationships, in addition to morphological characteristics of the scapula and humerus, affect the dimensions of the subacromial space. Each exhibits considerable interpersonal variability, which if only considering the mean, can lead to misleading population ...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2015.12.049
更新日期：2016-02-29 00:00:00
abstract：:Shape plays an important role in determining the biomechanical response of a structure. Specimen-specific finite element (FE) models have been developed to capture the details of the shape of biological structures and predict their biomechanics. Shape, however, can vary considerably across individuals or change due to...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/j.jbiomech.2009.08.036
更新日期：2010-01-19 00:00:00
abstract：:The in situ longitudinal strain of canine and porcine aortas was investigated. Marks of black water-resistant ink were placed on the aortas and the axial lengths between the marks were measured in situ and in vitro. When the aortas were cut, the retraction was measured and described by the stretch ratio, which is defi...
journal_title：Journal of biomechanics
pub_type： 杂志文章
doi：10.1016/0021-9290(94)00091-h
更新日期：1995-05-01 00:00:00
