Abstract:
:Whereas left ventricular assist device (LVAD) is the gold-standard therapy for patients with heart failure, gastrointestinal bleeding is one of the most common complications. LVAD implantation may remarkably impact aortic hemodynamics so that experimental and computational flow analyses can be used to study the disease mechanisms. Here we present an experimentally-calibrated computational model of the celiac trunk hemodynamic of a LVAD-supported patient who experienced bleeding after device implantation. Specifically, both particle image velocimetry (PIV) and echocardiography were used to measure and compare flow distributions in each branch of a phantom model of the patient abdominal aorta. Then, the distribution of wall shear stress (WSS) was estimated by computational flow analysis. At a cardiac output of 5 L/min, the highest flow division was found in the mesenteric artery (13.6% for PIV and 14.6% for echocardiography), while the left renal artery exhibited the lowest amount in the celiac trunk model (2.6% for PIV and 2.4% for echocardiography). Bland-Altman analysis demonstrated a high agreement between echocardiographic and PIV-related flow measurements, while computational flow analysis revealed that WSS was high in the LVAD graft anastomosis site and just after the ostia of both the celiac trunk and mesenteric artery. This altered shear stress distribution in the celiac trunk may lead to a flow-mediated mechanism of adverse remodeling of the von Willebrand factor and ultimately to gastrointestinal bleeding as seen clinically in this patient.
journal_name
Med Eng Physjournal_title
Medical engineering & physicsauthors
Scardulla F,Bellavia D,D'Acquisto L,Raffa GM,Pasta Sdoi
10.1016/j.medengphy.2017.06.029subject
Has Abstractpub_date
2017-09-01 00:00:00pages
47-54eissn
1350-4533issn
1873-4030pii
S1350-4533(17)30168-6journal_volume
47pub_type
杂志文章abstract::The internal carotid artery (ICA) has been proposed as an alternative site to the middle cerebral artery (MCA) to measure dynamic cerebral autoregulation (dCA) using transcranial Doppler ultrasound (TCD). Our aim was to test the inter-operator reproducibility of dCA assessment in the ICA and the effect of interaction ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.03.007
更新日期:2016-07-01 00:00:00
abstract::Foot pressure ulcers are a common complication of diabetes because of patient's lack of sensitivity due to neuropathy. Deep pressure ulcers appear internally when pressures applied on the foot create high internal strains nearby bony structures. Monitoring tissue strains in persons with diabetes is therefore important...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.04.017
更新日期:2016-09-01 00:00:00
abstract::Understanding the load mechanics of orthopaedic implants is important to be able to predict their behaviour in-vivo. Much research, both mechanical and clinical, has been carried out on hip and knee implants, but less has been written about the mechanics of wrist implants. In this paper, the load mechanics of the Univ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.02.008
更新日期:2016-06-01 00:00:00
abstract::Previous studies investigating thrombus formation have not focused on the physical interaction between red blood cells (RBCs) and thrombus, although they have been speculated that some pathological conditions such as microangiopathic hemolytic anemia (MAHA) stem from interactions between RBCs and thrombi. In this stud...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2012.01.003
更新日期:2012-12-01 00:00:00
abstract::Somatosensory evoked potential (SEP) testing has been widely applied to diagnosis of various neurological disorders. However, SEP recorded using surface electrodes is buried in noises, which makes the signal-to-noise ratio (SNR) very poor. Conventional averaging method usually requires up to thousands of raw SEP input...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2004.09.007
更新日期:2005-04-01 00:00:00
abstract::Compared to conventional deep brain stimulation (DBS) for patients with Parkinson's Disease (PD), the newer approach of adaptive DBS (aDBS), regulating stimulation on the basis of the patient's clinical state, promises to achieve better clinical outcomes, avoid adverse-effects and save time for tuning parameters. A re...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.02.007
更新日期:2016-05-01 00:00:00
abstract::In most computational fluid dynamic (CFD) analysis of the human lung, it has been assumed that the trachea and branches of the lung have smooth walls. In order to determine if this is a valid assumption, the effects of cartilage rings on airflow and particle deposition in the lungs was determined through conducting si...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2007.06.010
更新日期:2008-06-01 00:00:00
abstract::The results from studies of wave propagation in large arteries carried out over the last 25 years have shown that there is a good agreement among values of the imaginary part of the complex propagation coefficient, as expressed by pressure or flow-rate wave propagation velocity. However, there is considerable disparit...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(96)00073-2
更新日期:1997-04-01 00:00:00
abstract::Cerebral autoregulation (CA) is the mechanism that aims to maintain adequate cerebral perfusion during changes in blood pressure (BP). Transfer function analysis (TFA), the most reported method in literature to quantify CA, shows large between-study variability in outcomes. The aim of this study is to investigate the ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.02.001
更新日期:2016-05-01 00:00:00
abstract::Successful treatment of tumors with motion-adaptive radiotherapy requires accurate prediction of respiratory motion, ideally with a prediction horizon larger than the latency in radiotherapy system. Accurate prediction of respiratory motion is however a non-trivial task due to the presence of irregularities and intra-...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.04.021
更新日期:2016-08-01 00:00:00
abstract::Biomagnetic investigations in basic physiological research using animals require measurement devices different from commercial biomagnetometers used in human investigations. Two major problems have to be tackled in the design of such biomagnetometers. First, the spatial sampling needs to be much higher. Second, the di...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(99)00088-0
更新日期:1999-10-01 00:00:00
abstract::Understanding hip osteoarthritis requires new investigational tools for quantitative studies of biophysical and biomechanical properties as well as for determination of structure. Three new protocols to study pathological changes in cartilage and to measure cartilage thickness in intact human hips are described using ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2019.08.003
更新日期:2019-11-01 00:00:00
abstract::The investigation presented in this paper has attempted to study, from a fluid dynamics point of view, the consequences of the presence of a stent on the flow of blood. The method adopted is mainly by numerical simulation using a finite element technique, but visualization experiments and an analytical study have also...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00072-2
更新日期:2000-10-01 00:00:00
abstract::The deformation of soft tissue compromises the accuracy of image-guided surgery based on preoperative images, and restricts its applicability to surgery on or near bony structures. One way to overcome these limitations is to combine biomechanical models with sparse intraoperative data, in order to realistically warp t...
journal_title:Medical engineering & physics
pub_type: 杂志文章,评审
doi:10.1016/j.medengphy.2005.10.005
更新日期:2005-12-01 00:00:00
abstract::This paper describes a novel three-wire thermal flow sensor for medical applications. The present innovation for low-frequency measurements involves the use of a pulsed-wire anemometer with a comparatively large wire diameter (12.5 microm and larger) together with a novel signal processing approach. A small wire is he...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2004.06.002
更新日期:2004-10-01 00:00:00
abstract::Inserting the distal locking screws is a challenging step of the intramedullary nailing procedures due to the nail deformation that makes the proximally mounted targeting systems ineffective. A pre-planning methodology is proposed, based on an analytical model of the nail-bone construct, to predict the nail deformatio...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2019.09.012
更新日期:2019-12-01 00:00:00
abstract:AIMS:This study investigated the feasibility of automated differentiation between essential tissue types encountered during laparoscopic colorectal surgery using spectral analysis. METHODS:Wide band (440-1830 nm) spectra were collected using an optical fiber probe and spectrometer from freshly explanted, ex vivo, huma...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2013.01.004
更新日期:2013-07-01 00:00:00
abstract::The role and effect of preserved antegrade pulmonary blood flow (APBF) at the time of bidirectional cavopulmonary anastomosis (BCPA) in the management of single-ventricle physiology is controversial. We investigated the influence of APBF on the fluid dynamics of BCPA connection using computational fluid dynamics (CFD)...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2008.07.004
更新日期:2009-03-01 00:00:00
abstract::A system for acoustic analysis of pathological voices is proposed. The vocalized part of the voice signal is separated and all glottal cycles are traced by means of a cross-correlation detector. Based on the so determined beginning and duration of all glottal cycles, shimmer, jitter, several harmonics-to-noise ratios ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(02)00031-0
更新日期:2002-07-01 00:00:00
abstract::Understanding morphological features that characterize normal hip joint is critical and necessary for a more comprehensive definition of pathological presentations, such as femoroacetabular impingement and hip dysplasia. Based on anatomical observations that articular surfaces of synovial joints are better represented...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2018.07.001
更新日期:2018-09-01 00:00:00
abstract::The electrocardiogram (ECG) is a well-established technique for determining the electrical activity of the heart and studying its diseases. One of the most common pieces of information that can be read from the ECG is the heart rate (HR) through the detection of its most prominent feature: the QRS complex. This paper ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2015.03.019
更新日期:2015-06-01 00:00:00
abstract::Lateral epicondylitis (LE) is hypothesized to occur as a result of repetitive, strenuous and abnormal postural activities of the elbow and wrist. There is still a lack of understanding of how wrist and forearm positions contribute to this condition during common manual tasks. In this study the wrist kinematics and the...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2011.02.002
更新日期:2011-07-01 00:00:00
abstract::Artificial blood pumps play an increasingly important role in the treatment of end-stage cardiac failure. The fluid dynamics of blood flow through such devices crucially affects their clinical effectiveness. Specifically, if the flow of blood stagnates or slowly re-circulates thrombus formation can occur and the avoid...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/s1350-4533(00)00023-0
更新日期:2000-04-01 00:00:00
abstract::This study relates to eye fixation systems with combined optical and audio systems. Many devices for eye diagnostics and some devices for eye therapeutics require the patient to fixate on a small target for a certain period of time, during which the eyes do not move and data from substructures of one or both eyes are ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.05.004
更新日期:2016-08-01 00:00:00
abstract::There are several issues attributed with abdominal aortic aneurysm endovascular repair. The positioning of bifurcated stent-grafts (SG) may affect SG hemodynamics. The hemodynamics and geometrical parameters of crossing or non-crossing graft limbs have not being totally accessed. Eight patient-specific SG devices and ...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.09.011
更新日期:2016-12-01 00:00:00
abstract::The spectral analysis of crackles sounds has been carried out based on the assumption that they are stationary signals, and the majority of the work on the crackles was accomplished before the publication of the Computerized Respiratory Sound Analysis (CORSA) guidelines. This works characterizes crackles acquired from...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2012.06.009
更新日期:2013-04-01 00:00:00
abstract::This study employed a noncontact resonance frequency (RF) detection technique that was developed by our group to evaluate the interfacial bone in in vitro implant-bone models. Based on our method, the implant-bone structure was excited by the acoustic energy of a loudspeaker, and its vibration response was acquired wi...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2013.05.006
更新日期:2013-12-01 00:00:00
abstract::This investigation explored pattern recognition of EMG signals produced by shoulder area muscles to identify the performance of a select number of lower arm motions. The signals were modelled as fourth-order autoregressive processes with the parameters of the models used to classify the different motions. The recorded...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/1350-4533(94)90024-8
更新日期:1994-03-01 00:00:00
abstract::Two quantitative techniques have been evaluated to examine whether respiratory sinus arrhythmia can be detected in atrial fibrillation. Cyclical changes in heart rate during deep breathing indicating respiratory sinus arrhythmia were seen in 11/15 control patients, but only 1/44 patients with atrial fibrillation. Powe...
journal_title:Medical engineering & physics
pub_type: 临床试验,杂志文章
doi:10.1016/1350-4533(94)90061-2
更新日期:1994-07-01 00:00:00
abstract::Core decompression is the most common procedure for treatment of the early stages of osteonecrosis of the femoral head. The purpose of this study was to compare the biomechanical performance of four different bone graft substitutes combined with core decompression. Subject-specific finite element models generated from...
journal_title:Medical engineering & physics
pub_type: 杂志文章
doi:10.1016/j.medengphy.2016.05.008
更新日期:2016-09-01 00:00:00