Abstract：
:In 12 dogs anesthetised with alpha-chloralose and urethane, and beta-adrenergic blocked with propranolol, the cervical vagi were stimulated for 60 seconds with supramaximal constant current pulses at frequencies between 2.0 and 10 Hz. The time course of the recovery of the cardiac period response, after cessation of vagal stimulation, was analyzed using nonlinear curve fitting techniques. It was found that the recovery phase could be reliably fitted with a function consisting of the sum of up to three exponential terms. The first term has a moderate rate constant of 0.2260 +/- 0.0112 S-1 (SE) and is independent of vagal stimulus frequency and the preceding bradycardia. We propose that this term is associated with a recovery from the bradycardia with a rate constant indicative of the reduction of acetylcholine at the pacemaker caused by hydrolysis and washout. The second term has a small rate constant of 0.0499 +/- 0.0014 s-1 (SE) and a negative gain. This term describes the time course of the post vagal tachycardia observed at cessation of stimulation. It is also independent of stimulus frequency and the preceding bradycardia. The third term has a large and variable rate constant (range: 0.247-8.01 s-1) and becomes increasingly dominant when the preceding bradycardia is large. We propose that this third component arises from a rapid return of the pacemaker focus to the dominant location prior to vagal stimulation. The mathematical characterisation of this component is important to permit the accurate derivation of the time courses of the remaining two components. Curvilinear relationships exist between the gain parameters for each of the exponential terms and the preceding bradycardia.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Celler BG,Lovell NHdoi
10.1007/BF02584303subject
Has Abstractpub_date
1991-01-01 00:00:00pages
273-89issue
3eissn
0090-6964issn
1573-9686journal_volume
19pub_type
杂志文章abstract：:In this study, we introduce the fast wavelet transform as a method for characterizing maturational changes in electrocortical activity, respiratory activity, and blood pressure in fetal lambs in early (110-122 days), mid (123-135 days), and late (136-144 days) third trimester (term 145 days). Each recording was 2 hr i...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02584457
更新日期：1995-09-01 00:00:00
abstract：:Microfluidic devices fabricated using poly(dimethylsiloxane) (PDMS) polymer are routinely used for in vitro cell culture for a wide range of cellular assays. These assays typically involve the incubation of cultured cells with a drug molecule or a fluorescent marker while monitoring a cellular response. The accuracy o...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-012-0562-z
更新日期：2012-09-01 00:00:00
abstract：:There has been considerable debate on the relative importance of biochemical stimuli and mechanical deformation in neutrophil adhesion in lung capillaries, a process observed following bacterial infection in the body. In contrast to venules, where the vessel diameter is larger than the leukocyte diameter (6-9 microm) ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-008-9437-8
更新日期：2008-04-01 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
abstract：:The pulmonary microvasculature offers a heterogeneous barrier to the motion of large solutes as they pass between blood and lymph. While this barrier has been approximated by a few discrete pathways or by statistical ensembles of many pathways, these descriptions only partly capture the structural and functional prope...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02368425
更新日期：1990-01-01 00:00:00
abstract：:Deformational loading represents a primary component of the chondrocyte physical environment in vivo. This review summarizes our experience with physiologic deformational loading of chondrocyte-seeded agarose hydrogels to promote development of cartilage constructs having mechanical properties matching that of the par...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章,评审
doi：10.1023/b:abme.0000007789.99565.42
更新日期：2004-01-01 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：:The finite element method is employed to simulate two-dimensional (axisymmetric) drug diffusion from a finite drug reservoir into the skin. The numerical formulation is based on a general mathematical model for multicomponent nonlinear diffusion that takes into account the coupling effects between the different compon...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-005-5788-6
更新日期：2005-10-01 00:00:00
abstract：:Cochlear implantation consists in electrically stimulating the auditory nerve by inserting an electrode array inside the cochlea, a bony structure of the inner ear. In the absence of any visual feedback, the insertion results in many cases of damages of the internal structures. This paper presents a feasibility study ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-020-02671-1
更新日期：2020-10-30 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：:Double-exposure holographic interferometry is a contactless whole-field method. Dimensional changes are visualized as a series of interference fringes overlaid on the holographic image of the femur, where each fringe represents 0.316 micron (half the wavelength of the laser light) of motion. Interferograms for intact ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02364168
更新日期：1987-01-01 00:00:00
abstract：:Articular cartilage is an avascular connective tissue responsible for bearing loads. Cell signaling plays a central role in cartilage homeostasis and tissue engineering by directing chondrocytes to synthesize/degrade the extracellular matrix or promote inflammatory responses. The aim of this paper was to investigate a...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-017-1964-8
更新日期：2018-02-01 00:00:00
abstract：:The objective of this paper is to review the theoretical basis and clinical application of electrical impedance plethysmography in the noninvasive evaluation of peripheral arterial and venous disease. Theoretical, experimental and clinical studies have not demonstrated a direct relationship between electrical impedanc...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02410294
更新日期：1984-01-01 00:00:00
abstract：:A search for robust noninvasive methods permitting to discern the respiration subtle peculiarities in mammals is a topical issue. A novel approach called "sorption-enhanced infrared thermography" (SEIRT), helping to solve this problem, is described. Its benefits spring from the integration of the infrared thermography...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-018-2018-6
更新日期：2018-07-01 00:00:00
abstract：:The objectives were as follows: (1) estimating mean value of the overall hemoglobin glycation rate constant (k); (2) analyzing inter-individual variability of k; (3) verifying ability of the hemoglobin A1c (HbA1c) formation model to predict changes of HbA1c during red blood cells cultivation in vitro and to reproduce ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-011-0366-6
更新日期：2011-11-01 00:00:00
abstract：:Tissue engineering strategies have utilized a wide spectrum of synthetic and naturally-derived scaffold materials. Synthetic scaffolds are better defined and offer the ability to precisely and reproducibly control their properties, while naturally-derived scaffolds typically have inherent biological and structural pro...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章,评审
doi：10.1007/s10439-014-1192-4
更新日期：2015-03-01 00:00:00
abstract：:A major drawback in the operation of mechanical heart valve prostheses is thrombus formation in the near valve region. Detailed flow analysis in this region during the valve closure phase is of interest in understanding the relationship between shear stress and platelet activation. A fixed-grid Cartesian mesh flow sol...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-006-9194-5
更新日期：2006-10-01 00:00:00
abstract：:A mathematical model has been developed to investigate previously obtained experimental findings relating to the activation of factor X by surface-bound tissue factor--factor VIIa (TF:VIIa) in a tubular flow reactor. In those experiments, factor X was perfused through a microcapillary tube over a range of flow (shear)...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02660888
更新日期：1996-05-01 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：:The compression of blood vessels by surrounding tissue is an important problem in hemodynamics, most prominently in studies relating to the heart. In this study we consider a long tube of elliptic cross section as an idealization of the geometry of a compressed blood vessel. An exact solution of the governing equation...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.106
更新日期：1998-09-01 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：:Phospholipids have been identified by thin-layer chromatography in appreciable quantities in pericardial fluid taken from 12 dogs and found to include sphingomyelin and phosphatidylcholines, -ethanolamines, -inositols and -serines--the cholines predominating. The extracts, the synthetic surfactants and a mixture of sy...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/BF02584258
更新日期：1985-01-01 00:00:00
abstract：:Continuous flow left ventricular devices (CF-LVADs) support the failing heart at a constant speed and alters the loads on the aortic valve. This may cause insufficiency in the aortic valve under long-term CF-LVAD support. The aim of this study is to assess the aortic valve function under varying speed CF-LVAD support....
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-014-1204-4
更新日期：2015-08-01 00:00:00
abstract：:In this paper, we present the application of a semi-global inverse method for determining material parameters of biological tissues. The approach is based on the successive response surface method, and is illustrated by fitting constitutive parameters to two nonlinear anisotropic constitutive equations, one for aortic...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-005-8338-3
更新日期：2005-12-01 00:00:00
abstract：:To study the effects of compressive straining on muscle cell deformation and damage an in vitro model system was developed. Myoblasts were seeded in agarose constructs and cultured in growth medium for 4 days. Subsequently, the cells were allowed to fuse into multinucleated myotubes for 8 days in differentiation mediu...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1114/1.1349698
更新日期：2001-02-01 00:00:00
abstract：:Understanding the characteristic morphology of our brain remains a challenging, yet important task in human evolution, developmental biology, and neurosciences. Mathematical modeling shapes our understanding of cortical folding and provides functional relations between cortical wavelength, thickness, and stiffness. Ye...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-015-1312-9
更新日期：2015-07-01 00:00:00
abstract：:Basic fibroblast growth factor (FGF-2) is a potent angiogenic growth factor involved in the development of diseases such as cancer, atherosclerosis, and heart and limb ischemia, as well as normal wound healing and tissue development. Despite being one of the most heavily studied angiogenic growth factors, the binding ...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1023/b:abme.0000030231.88326.78
更新日期：2004-05-01 00:00:00
abstract：:A method of investigating head acceleration and intracranial dynamics from stick impacts in girls' and women's lacrosse was developed using headform impact experiments and a finite element head model. Assessing the likelihood of head injury due to stick-head impacts is of interest in girls' and women's lacrosse due to...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-014-1091-8
更新日期：2014-12-01 00:00:00
abstract：:A mathematical model is presented that estimates joint kinematics and kinetics using measured external resultant loads and readily available parameters. The musculo-skeletal system was represented by a planar three degrees of freedom open kinematic chain. Information extraction was limited to the flexion-extension fun...
journal_title：Annals of biomedical engineering
pub_type： 临床试验,杂志文章
doi：10.1023/b:abme.0000030241.26857.75
更新日期：2004-05-01 00:00:00
abstract：:The purpose of the study was to examine the effects of arterial coculture conditions on the transport properties of several in vitro endothelial cell (EC)-smooth muscle cell (SMC)-porous filter constructs in which SMC were grown to confluence first and then EC were inoculated. This order of culturing simulates the env...
journal_title：Annals of biomedical engineering
pub_type： 杂志文章
doi：10.1007/s10439-015-1421-5
更新日期：2016-05-01 00:00:00
