Abstract：
:A numerical single path model of respiratory gas exchange with distributed alveolar gas sources was used to estimate the anatomical changes in small peripheral airways such as occur in chronic obstructive pulmonary diseases (COPD). A previous sensitivity analysis of the single path model showed that decreasing total acinar airway cross-sectional area by an area reduction factor, R, results in computed gas expirograms with Phase III steepening similar to that observed in COPD patients. From experimental steady state CO2 washout data recorded from six healthy subjects and six COPD patients, optimized area reduction factors for the single path model were found that characterize peripheral airway anatomy for each subject. Area reduction factors were then combined with measured functional residual capacity data to calculate the normalized peripheral airspace diameters in a given subject, relative to the airspace diameters in the generations of an idealized standard lung. Mean area reduction factors for the patient subgroup were 63% of those for the healthy subgroup, which is related to the gas transport limitation observed in disease. Mean airspace sizes for the patient subgroup were 235% of the healthy subgroup, which characterizes the increase in size and reduction in number of peripheral airspaces due to tissue erosion in emphysema. From these results, the air-phase diffusive conductance in COPD patients was calculated to be 32% of the mean value in the healthy subjects. These findings correlated well with standard pulmonary function test data for the patients and yield the recovery of acinar airway information from gas washout by combining the single path model with experimental measurements.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Schwardt JD,Neufeld GR,Baumgardner JE,Scherer PWdoi
10.1007/BF02368236subject
Has Abstractpub_date
1994-05-01 00:00:00pages
293-306issue
3eissn
0090-6964issn
1573-9686journal_volume
22pub_type
杂志文章abstract：:The toxic or therapeutic effect of an inhaled aerosol is highly dependent upon the site and extent of deposition in the lung. A novel MRI-based method was used to quantify the spatial distribution of particles in the rat lung. Rats were exposed to 0.95 μm-diameter iron oxide particles in a controlled manner (N = 6) or...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-013-0745-2
更新日期：2013-05-01 00:00:00
abstract：:Experimental studies have shown that cardiac fibroblasts are electrically inexcitable, but can contribute to electrophysiology of myocardium in various manners. The aim of this computational study was to give insights in the electrophysiological role of fibroblasts and their interaction with myocytes. We developed a m...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-007-9405-8
更新日期：2008-01-01 00:00:00
abstract：:The multiphoton fluorescence recovery after photobleaching (MP-FRAP) technique has been developed to measure the three-dimensional (3D) solute diffusion within biological systems. However, current 3D MP-FRAP models are based on isotropic diffusion and spatial domain analysis. The 3D anisotropic diffusion and frequency...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-013-0939-7
更新日期：2014-03-01 00:00:00
abstract：:High energy laser has emerged to be an important surgical tool in medical technology. However, the application of laser energy to drill or cut a bone is still in an experimental state. In order to estimate the adequacy of laser heating of bone surface and at the same time minimize the damage to the bone tissue, we dev...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02363565
更新日期：1987-01-01 00:00:00
abstract：:Fingertips wrinkle due to long exposure to water. The biological reason for this morphological change is unclear and still not fully understood. There are two main hypotheses for the underlying mechanism of fingertip wrinkling: the 'shrink' model (in which the wrinkling is driven by the contraction of the lower layers...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-016-1764-6
更新日期：2017-04-01 00:00:00
abstract：:Wall stress analysis of abdominal aortic aneurysm (AAA) is a promising method of identifying AAAs at high risk of rupture. However, neglecting residual strains (RS) in the load-free configuration of patient-specific finite element analysis models is a sever limitation that strongly affects the computed wall stresses. ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-013-0749-y
更新日期：2013-07-01 00:00:00
abstract：:Femoral neck fractures are a relevant clinical and social problem. The aim of this study was to improve the prediction of patients at-risk of femoral neck fracture with respect to the current densitometric-based methods. In particular, finite element models were used to assess the prediction accuracy obtained by combi...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1495866
更新日期：2002-06-01 00:00:00
abstract：:Abdominal aortic aneurysms occur in as much as 2-3% of the population, and their rupture produces a mortality rate of 78-94% (1), causing 15,000 deaths per year in the U.S. alone. As an investigation into the mechanical factors that lead to aneurysm rupture, flow field measurements are presented for steady flow throug...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02368298
更新日期：1995-01-01 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：:The complexity of the coronary circulation especially in the deep layers largely evades experimental investigations. Hence, virtual/computational models depicting structure-function relation of the entire coronary vasculature including the deep layer are imperative. In order to interpret such anatomically based models...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-007-9278-x
更新日期：2007-05-01 00:00:00
abstract：:The unique resource constraints, urgency, and virulence of the coronavirus disease 2019 pandemic has sparked immense innovation in the development of barrier devices to protect healthcare providers from infectious airborne particles generated by patients during airway management interventions. Of the existing devices,...
journal_title：Annals of biomedical engineering
pub_type： 社论
doi：10.1007/s10439-020-02599-6
更新日期：2020-10-01 00:00:00
abstract：:This paper outlines a comprehensive parametric approach for quantifying mechanical properties of spatially heterogeneous thin biological specimens such as human breast tissue using contact-mode Atomic Force Microscopy. Using inverse finite element (FE) analysis of spherical nanoindentation, the force response from hyp...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-014-1057-x
更新日期：2014-09-01 00:00:00
abstract：:Functional outcomes, such as joint flexion and gait, are important indicators of efficacy in musculoskeletal research. Current technologies that objectively assess these parameters, including visual tracking systems and force plates, are challenging to deploy in long-term translational and clinical studies. To that en...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-018-2105-8
更新日期：2018-12-01 00:00:00
abstract：:The Veterans Health Administration determined that over 250,000 U.S. service members were diagnosed with a traumatic brain injury (TBI) between 2008 and 2018, of which a great proportion were due to blast exposure. Although the penetrating (secondary) and inertia-driven (tertiary) phases of blast-induced TBI (bTBI) ha...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-019-02437-4
更新日期：2020-04-01 00:00:00
abstract：:We compare the influence of time-frequency methods on analysis of time-varying renal autoregulation properties. Particularly, we examine if detection probabilities are similar for amplitude and frequency modulation for a modulated simulation signal among five time-frequency approaches, and if time-varying changes in s...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-012-0625-1
更新日期：2013-01-01 00:00:00
abstract：:This paper presents the permeability analysis of neuroactive drugs and correlation with in vivo brain/plasma ratios in a dynamic microfluidic blood-brain barrier (BBB) model. Permeability of seven neuroactive drugs (Ethosuximide, Gabapentin, Sertraline, Sunitinib, Traxoprodil, Varenicline, PF-304014) and trans-endothe...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-014-1086-5
更新日期：2014-12-01 00:00:00
abstract：:The epidermal growth factor (EGF) is a growth factor with effects on many cell types and tissue. Morphometric and passive biomechanical properties were studied in isolated segments of the esophagus in 22 EGF-treated rats and 12 control rats. The rats were divided into groups with EGF treatment for 2, 4, 7, and 14 days...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1575758
更新日期：2003-06-01 00:00:00
abstract：:This paper presents two related methods for registering an image of an anatomical object with data from sensors arranged on the object. One method is described with reference to a test case involving a rectangular electrode plaque disposed on a heart surface, which is imaged with MRI. Data from the electrodes is fused...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-007-9350-6
更新日期：2007-10-01 00:00:00
abstract：:Kiani et al. (Kiani, M. F., A. R. Pries, L. L. Hsu, I. H. Sarelius, and G. R. Cokelet, Am. J. Physics. 266: H1822-H1828, 1994) suggested that blood velocity, hematocrit, and nodal pressures can oscillate spontaneously in large microvascular networks in the absence of biological control. This paper presents a model of ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1306346
更新日期：2000-06-01 00:00:00
abstract：:We present a method of measuring force response of a single living cell, attached to a substrate, in situ, by a functionalized microelectromechanical systems sensor that applies local deformation on the cell. The sensor is a single crystal silicon microcantilever beam with prescribed shape and geometry, and is coated ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1591189
更新日期：2003-09-01 00:00:00
abstract：:Computational modeling and simulation has become more common in design and development of bioprosthetic heart valves. To have a reliable computational model, considering accurate mechanical properties of biological soft tissue is one of the most important steps. The goal of this study was to present a non-invasive mat...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-018-02129-5
更新日期：2019-01-01 00:00:00
abstract：:We propose a new method for guiding catheter ablation procedures to abolish sites of origin of arrhythmias. This method models both cardiac electrical activity and current pulses delivered from the tip of the ablation catheter with a single equivalent moving dipole (SEMD). The SEMD parameters are obtained from analysi...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1567281
更新日期：2003-05-01 00:00:00
abstract：:Pelvic floor muscle (PFM) strength measurement provides useful information for the study of pelvic floor dysfunctions. Vaginal digital palpation, intravaginal pressure measurements, and the use of a dynamometric speculum represent currently available clinical methods for evaluating PFM strength. However, none of these...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-009-9728-8
更新日期：2009-08-01 00:00:00
abstract：:Due to its unique non-invasive microstructure probing capabilities, diffusion tensor imaging (DTI) constitutes a valuable tool in the study of fiber orientation in skeletal muscles. By implementing a DTI sequence with judiciously chosen directional encoding to quantify in vivo the microarchitectural properties in the ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-009-9783-1
更新日期：2009-12-01 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：:The impedance of a monopolar electrode immersed in an environmental volume conductor consists of two parts; the impedance of the active electrode-electrolyte interface, and the resistance of the environmental conductor. Two studies were carried out to quantitate these components. First, impedance-frequency data were c...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02368609
更新日期：1992-01-01 00:00:00
abstract：:Three-dimensional (3D) measurement of the spine can provide important information for functional, developmental, diagnostic, and treatment-effect evaluations. However, existing measurement techniques are either 2-dimensional, highly invasive, or involve a high radiation dose, prohibiting their widespread and repeated ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-016-1599-1
更新日期：2016-10-01 00:00:00
abstract：:To study the effects of smooth muscle contraction and relaxation on the strain and stress distribution in the vascular wall, a mathematical model was proposed. The artery was assumed to be a thick-walled orthotropic tube made of nonlinear, incompressible elastic material. Considering that the contraction of smooth mus...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.191
更新日期：1999-07-01 00:00:00
abstract：:We propose a multifrequency energy transmission scheme for annular phased arrays in deep-body hyperthermia. The problem of frequency dependent resonance effects reported in hyperthermia phantom calibration studies, leading to skewed energy deposition patterns and unwanted energy maxima (hot spots), is addressed by com...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1430749
更新日期：2002-01-01 00:00:00
abstract：:Mechanical ventilation is a life-support therapy for intensive care patients suffering from respiratory failure. To reduce the current rate of ventilator-induced lung injury requires ventilator settings that are patient-, time-, and disease-specific. A common lung protective strategy is to optimise the level of positi...
journal_title：Annals of biomedical engineering
pub_type： 临床试验,杂志文章
doi：10.1007/s10439-019-02253-w
更新日期：2019-07-01 00:00:00
