Abstract:
:Left ventricular (LV) diastolic filling is limited by the constraining effects exerted by the pericardium (PE) and the lung/chest wall. The aim of the present study was to assess the validity of various estimates of external cardiac constraint, compared to pericardial surface pressure (Ppe) measured lateral to the LV myocardium. In nine anesthetized dogs we measured Ppe, pleural surface pressure (Ppt) (lateral to the pericardium) and esophageal pressure (Pes) under conditions of volume loading and positive end-expiratory pressure (PEEP). We measured Ppe and Ppl with flat, liquid-containing silastic rubber balloons and Pes with an air-containing cylindrical balloon. After instrumentation, the chest was resealed and continuous suction (-5 mm Hg, 1 mm Hg = 0.133 kPa) was maintained. Volume loading with incremental intravenous infusions of saline was used to increase LV end-diastolic pressure to 20-25 mm Hg. PEEP of 0, 10 and 20 mm Hg were applied at baseline and after each increment of volume loading. At low volume, increases in PEEP caused simultaneous increases in LV end-diastolic pressure (P less than 0.01) and in Ppe (P less than 0.0001) but a reduction in transmural LV pressure (P less than 0.0005). Ppl and Pes both increased with PEEP (P less than 0.001 and P less than 0.01, respectively). However, Ppe always exceeded Ppl, while Pes remained at only approximately 1/3 Ppl throughout. Volume loading caused a significant increase in Ppe (P less than 0.0001) and a smaller, but significant increase in Ppl (P less than 0.05). Pes remained unchanged during volume loading. Thus external cardiac constraint increased markedly during volume loading and PEEP as evidenced by a marked elevation of Ppe. Both Ppl and Pes markedly underestimated this increase. Therefore, calculation of transmural LV pressure by subtracting pleural or esophageal pressure from intracavitary pressure can lead to overestimation of LV preload. The decrease in cardiac output during PEEP occurs secondary to decreased preload, i.e. decreased transmural pressure and end-diastolic dimension. Analysis of performance using cardiac function curves does not suggest a change in contractility with PEEP.
journal_name
Ann Biomed Engjournal_title
Annals of biomedical engineeringauthors
Kingma I,Smiseth OA,Frais MA,Smith ER,Tyberg JVdoi
10.1007/BF02584288subject
Has Abstractpub_date
1987-01-01 00:00:00pages
331-46issue
3-4eissn
0090-6964issn
1573-9686journal_volume
15pub_type
杂志文章abstract::During the fetal-to-neonatal transition, transvalvular pressures (TVPs) on the aortic and pulmonary valves change dramatically-but differently for each valve. We have examined changes in the molecular stability and crosslinking of collagen during this transition. Aortic and pulmonary valves were harvested from fetal a...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-0061-z
更新日期:2010-09-01 00:00:00
abstract::Maintenance of movement accuracy relies on motor learning, by which prior errors guide future behavior. One aspect of this learning process involves the accurate generation of predictions of movement outcome. These predictions can, for example, drive anticipatory movements during a predictive-saccade task. Predictive ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-012-0669-2
更新日期:2013-08-01 00:00:00
abstract::Integration of repair tissue is a key indicator of the long-term success of cell-based therapies for cartilage repair. The objective of this study was to compare the in vitro chondrogenic differentiation and integration of agarose hydrogels seeded with either chondrocytes or bone marrow-derived mesenchymal stem cells ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-009-9791-1
更新日期:2009-12-01 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::Extraction of the cardiac surfaces of interest from multi-detector computed tomographic (MDCT) data is a pre-requisite step for cardiac analysis, as well as for image guidance procedures. Most of the existing methods need manual corrections, which is time-consuming. We present a fully automatic segmentation technique ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章,随机对照试验
doi:10.1007/s10439-015-1422-4
更新日期:2016-05-01 00:00:00
abstract::Mechanical interactions during angiogenesis, i.e., traction applied by neovessels to the extracellular matrix and the corresponding deformation, are important regulators of growth and neovascularization. We have previously designed, implemented, and validated a coupled model of angiogenesis in which a discrete microve...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-015-1334-3
更新日期:2015-07-01 00:00:00
abstract::Irreversible electroporation (IRE), is a new non-thermal tissue ablation technology in which brief high electric field pulses are delivered across the target tissue to induce cell death by irreversible permeabilization of the cell membrane. A deficiency of conventional IRE is that the ablation zone is relatively small...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-019-02258-5
更新日期:2019-07-01 00:00:00
abstract::For an optimal guidance of the rehabilitation therapy of stroke patients in an in-home setting, objective, and patient-specific performance assessment of arm movements is needed. In this study, metrics of hand movement relative to the pelvis and the sternum were estimated in 13 stroke subjects using a full body ambula...
journal_title:Annals of biomedical engineering
pub_type: 临床试验,杂志文章
doi:10.1007/s10439-014-1198-y
更新日期:2015-02-01 00:00:00
abstract::Step-off edges and tissue interfaces are prevalent in cartilage injury such as after intra-articular fracture and reduction, and in focal defects and surgical repair procedures such as osteochondral graft implantation. It would be useful to assess the function of injured or donor tissues near such step-off edges and t...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1023/b:abme.0000017553.01798.12
更新日期:2004-03-01 00:00:00
abstract::Cell migration paths of mammary epithelial cells (expressing different versions of the promigratory tyrosine kinase receptor Her2/Neu) were analyzed within a bimodal framework that is a generalization of the run-and-tumble description applicable to bacterial migration. The mammalian cell trajectories were segregated i...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-008-9592-y
更新日期:2009-01-01 00:00:00
abstract::Collagen is known to be a viscoelastic material and therefore is an important source of time dependent behavior in soft tissue. Though there are material models for soft tissue that rely on properties and structure of constituent collagen fibers, such models generally utilize only the elastic properties of collagen, a...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-006-9124-6
更新日期:2006-07-01 00:00:00
abstract::The aim of this study was to establish in vitro bench-tests of left atrial appendage occlusion (LAAo) devices regarding tug force, radial force and sealing capacity. Two LAAo devices, namely the WATCHMAN™ and the Occlutech®, of three different sizes underwent testing in novel dedicated in vitro setups. Radial force wa...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-2057-z
更新日期:2018-09-01 00:00:00
abstract::Abnormal scapular movement is widely believed to be an important factor in clinical pathology of the shoulder joint complex. Validated non-invasive techniques for measuring scapular movement have been developed, but the effect of marker placement on accuracy is unknown. The objective of this study was to determine the...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-0185-1
更新日期:2011-02-01 00:00:00
abstract::Crowding can substantially affect the transition of a protein between its native (N) and unfolded (U) states via volume exclusion effects. Also, it influences considerably the aggregation (A) of unfolded proteins. To examine the details, we developed an approach for computing the kinetic rates of the process N <--> U ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-005-5780-8
更新日期:2005-08-01 00:00:00
abstract::This article presents a computer-aided detection system for capsule endoscopy (CE) images using contourlet-based color textural features to recognize tumors in the digestive tract. As tumor exhibits rich information in color texture, a novel color texture feature based on contourlet transform is proposed to describe c...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-011-0380-8
更新日期:2011-12-01 00:00:00
abstract::We propose a novel method to reconstruct the hypothetical geometry of the healthy vasculature prior to intracranial aneurysm (IA) formation: a Frenet frame is calculated along the skeletonization of the arterial geometry; upstream and downstream boundaries of the aneurysmal segment are expressed in terms of the local ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-013-0794-6
更新日期:2013-07-01 00:00:00
abstract::Platelet thrombosis under arterial conditions remains a large clinical problem. Previous in vitro experiments have concentrated on early adherence without thrombotic occlusion. We have developed a controllable hemodynamic system that creates intravascular thrombosis to occlusion. Lightly heparinized (3.5 USP units/mL)...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-011-0296-3
更新日期:2011-07-01 00:00:00
abstract::In order to obtain the first quantitative measurements of the in vivo stresses in early-stage amphibian embryos, we developed a novel instrument that uses a pair of parallel wires that are glued to the surface of an embryo normal to the direction in which the stress is to be determined. When a slit is made parallel to...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-006-9250-1
更新日期:2007-04-01 00:00:00
abstract::A mathematical model of heat, water and soluble gas exchange in the airways and alveoli was used to predict the location of soluble gas exchange in the lung. A previously published model of heat, water and soluble gas exchange in the airways was improved by incorporating anatomical data on the airway wall to better de...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1114/1.1630600
更新日期:2003-12-01 00:00:00
abstract::Fractal time series analysis methods are commonly used for analyzing center of pressure (COP) signals with the goal of revealing the underlying neuromuscular processes for upright stance control. The use of fractal methods is often coupled with the assumption that the COP is an instance of fractional Gaussian noise (f...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-012-0646-9
更新日期:2013-08-01 00:00:00
abstract::The pericellular matrix (PCM) is a region of tissue that surrounds chondrocytes in articular cartilage and together with the enclosed cells is termed the chondron. Previous studies suggest that the mechanical properties of the PCM, relative to those of the chondrocyte and the extracellular matrix (ECM), may significan...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-005-4479-7
更新日期:2005-10-01 00:00:00
abstract::The kidney is one of the most radiosensitive organs; it is the primary dose-limiting organ in radiotherapies for upper abdominal cancers. The role of mitochondrial redox state in the development and treatment of renal radiation injury, however, remains ill-defined. This study utilizes 3D optical cryo-imaging to quanti...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-019-02255-8
更新日期:2019-07-01 00:00:00
abstract:BACKGROUND:We present a fundamental theoretical framework for analysis of energy dissipation in any component of the circulatory system and formulate the full energy budget for both venous and arterial circulations. New indices allowing disease-specific subject-to-subject comparisons and disease-to-disease hemodynamic ...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-009-9650-0
更新日期:2009-04-01 00:00:00
abstract::In this paper, a novel cell stretcher design that mimics the real-time stretch of the heart wall is introduced. By culturing cells under stretched conditions that mimics the mechanical aspects of the native cardiac environment, better understanding on the role of biomechanical signaling on cell development can be achi...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-014-0976-x
更新日期:2014-05-01 00:00:00
abstract::This study was aimed at developing a physical model, supported by experimental observations, to describe the formation and growth of microbubbles seen in patients with mitral mechanical heart valves (MHV). This phenomenon, often referred to as high intensity transient signals (HITS), appears as bright, intense, high-v...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1114/1.231
更新日期:1999-11-01 00:00:00
abstract::The induction of angiogenesis is a promising therapeutic strategy for the amelioration of peripheral arterial disease (PAD). This occlusive disease results in muscle ischemia, and neovascularization is a route to increasing the perfusion in the tissue. The vascular endothelial growth factor (VEGF) family of potent pro...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-007-9303-0
更新日期:2007-06-01 00:00:00
abstract::This experimental work focused on the sensor selection for the development of a needle-like instrument to treat small isolated cartilage defects with hydrogels. The aim was to identify the most accurate and sensitive imaging method to determine the location and size of defects compared to a gold standard (µCT). Only i...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-018-2073-z
更新日期:2018-11-01 00:00:00
abstract::Registration of bone structures is a common problem in medical research as well as in clinical applications. Intrasubject rigid 3D monomodality registration of segmented bone structures of CT images and multimodality registration of muMR and segmented muCT bone images were performed with the multiresolution intensity-...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-010-9981-x
更新日期:2010-07-01 00:00:00
abstract::Most non-invasive blood pressure measurements are based on either the auscultatory or the oscillometric technique. In this study, we performed an extensive analysis of the signals, i.e., responses of a microphone implanted in the cuff and pressure changes in the cuff, which can be recorded during such measurements. We...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-009-9853-4
更新日期:2010-03-01 00:00:00
abstract::Despite the use of helmets in American football, brain injuries are still prevalent. To reduce the burden of these injuries, novel impact mitigation systems are needed. The Vicis Zero1 (VZ1) American football helmet is unique in its use of multi-directional buckling structures sandwiched between a deformable outer she...
journal_title:Annals of biomedical engineering
pub_type: 杂志文章
doi:10.1007/s10439-020-02472-6
更新日期:2020-05-01 00:00:00