Abstract：
:The boundary-element method (BEM) is widely used for electrocardiogram (ECG) simulation. Its major disadvantage is its perceived inability to deal with the anisotropic electric conductivity of the myocardial interstitium, which led researchers to represent only intracellular anisotropy or neglect anisotropy altogether. We computed ECGs with a BEM model based on dipole sources that accounted for a "compound" anisotropy ratio. The ECGs were compared with those computed by a finite-difference model, in which intracellular and interstitial anisotropy could be represented without compromise. For a given set of conductivities, we always found a compound anisotropy value that led to acceptable differences between BEM and finite-difference results. In contrast, a fully isotropic model produced unacceptably large differences. A model that accounted only for intracellular anisotropy showed intermediate performance. We conclude that using a compound anisotropy ratio allows BEM-based ECG models to more accurately represent both anisotropies.
journal_name
Med Biol Eng Computjournal_title
Medical & biological engineering & computingauthors
Potse M,Dubé B,Vinet Adoi
10.1007/s11517-009-0472-xsubject
Has Abstractpub_date
2009-07-01 00:00:00pages
719-29issue
7eissn
0140-0118issn
1741-0444journal_volume
47pub_type
杂志文章abstract：:The Pennes bioheat equation and finite element method (FEM) are used to solve for the temperature distributions in the spinal cord and cerebrospinal fluid (CSF) during 30 min of cooling for spinal cord injury (SCI) patients. The average CSF and spinal cord temperatures are reduced by 3.48 and 2.72 degrees C, respectiv...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-009-0543-z
更新日期：2010-02-01 00:00:00
abstract：:An efficient and novel modeling approach is proposed in this paper for identifying proteins or genes involved in melanoma skin cancer. Two types of classifiers are modeled, based on the chemical structure and hydropathy property of amino acids. These classifiers are further implemented using NI LabVIEW-based hardware ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-020-02241-6
更新日期：2020-10-01 00:00:00
abstract：:The study focuses on the problems of dimensionality reduction by means of principal component analysis (PCA) in the context of single-trial EEG data classification (i.e. discriminating between imagined left- and right-hand movement). The principal components with the highest variance, however, do not necessarily carry...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02522476
更新日期：1998-05-01 00:00:00
abstract：:A method for making a current-ratio map to determine the ischaemic area of angina pectoris (AP) patients has been developed. This method uses a current-arrow map calculated using a ORS wave from 64-channel magnetocardiogram (MCG) signals. The current-ratio map can be calculated from the ratio of an exercise-induced cu...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02345263
更新日期：2001-01-01 00:00:00
abstract：:The development of an active implantable device for measuring electrocardiogram (ECG) is presented. The study is a part of a project which aims at developing implantable ECG instrumentation with wireless data and power transfer ( http://www.ele.tut.fi/tule ). The developed implant presented here has all the measuremen...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章,评审
doi：10.1007/s11517-007-0264-0
更新日期：2007-12-01 00:00:00
abstract：:The regulation of the coronary circulation is a complex paradigm in which many inputs that influence vasomotor tone have to be integrated to provide the coronary vasomotor adjustments to cardiac metabolism and to perfusion pressure. We hypothesized that the integration of many disparate signals that influence membrane...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-008-0329-8
更新日期：2008-05-01 00:00:00
abstract：:Instantaneous backflow through central clearance of bileaflet heart valves at the instant of closure is investigated. An Edwards-Duromedics valve in the mitral position is employed to measure the transient pressures near the entrance and exit region in an in vitro flow chamber. A region surrounding the clearance is mo...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02510497
更新日期：1995-05-01 00:00:00
abstract：:We have successfully developed a multiscale acoustic-resolution photoacoustic tomography system in a single imaging platform. By switching between ultrasound transducers (center frequencies 5 and 40 MHz) and optical condensers, we have photoacoustically imaged microvasculatures of small animals in vivo at different sc...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-014-1182-6
更新日期：2016-03-01 00:00:00
abstract：:A new method of quantifying dermal perfusion on a regional basis using a dynamic thermographic technique is investigated. The technique is based on the relationship between dermal perfusion and the rate of skin surface reheating following the application of a transient cold challenge predicted by a theoretical model. ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02441468
更新日期：1989-09-01 00:00:00
abstract：:The successful decoding of kinematic variables from spike trains of motor cortical neurons is essential for cortical neural prosthesis. Spike trains from each single unit must be extracted from extracellular neural signals and, thus, spike detection and sorting procedure is indispensable but the detection and sorting ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-005-0009-x
更新日期：2006-03-01 00:00:00
abstract：:The aim of the study was to assess the wavelength dependence of the UV absorbance during monitoring of different compounds in the dialysate. UV absorbance was determined by using a double-beam spectrophotometer on dialysate samples taken at pre-determined times during dialysis, over a wavelength range of 180-380 nm. C...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02348430
更新日期：2003-05-01 00:00:00
abstract：:Vertebral fractures are common in children with osteogenesis imperfecta (OI). Current imaging methods for fracture detection (X-ray and DXA) use ionising radiation. This pilot study explored whether the alteration in blood flow in vertebral fractures results in skin temperature changes that may be detected using high ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-018-1806-3
更新日期：2018-09-01 00:00:00
abstract：:Impedance cardiography is a low-cost noninvasive technique, based on monitoring of the thoracic impedance, for estimation of stroke volume (SV). Impedance cardiogram (ICG) is the negative of the first derivative of the impedance signal. A technique for beat-to-beat SV estimation using impedance cardiography and artifi...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-017-1752-5
更新日期：2018-06-01 00:00:00
abstract：:Understanding the hemodynamics surrounding the venous valve environment is of a great importance for prosthetic valves design. The present study aims to evaluate the effect of leaflets' stiffening process on the venous valve hemodynamics, valve's failure on the next proximal valve hemodynamics and valve's failure in a...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-016-1575-9
更新日期：2017-06-01 00:00:00
abstract：:Obstructive sleep apnea syndrome (OSAS) is a major public health problem. The golden reference for diagnosing OSAS is the sleep-laboratory based polysomnography (PSG). However, screening of population for OSAS may be practical and cost efficient only through ambulatory home recordings. In this work we aimed to design,...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-008-0418-8
更新日期：2009-01-01 00:00:00
abstract：:Dislocation is a serious potential complication of total hip replacement. Previous studies have proposed a newly developed total hip structure that meets the required oscillation angle of 120°, for which the chamfer on the acetabular liner rim was designed to enable the neck to impinge on the chamfer over a large area...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-017-1673-3
更新日期：2018-01-01 00:00:00
abstract：:Both invasive left-ventricular pressure measurements and non-invasive colour M-mode echographic measurements have shown the existence of intraventricular pressure gradients (IVPGs) during early filling. The mechanisms responsible for these IVPG cannot be completely explained by the experiments. Therefore a one-dimensi...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02513338
更新日期：1999-07-01 00:00:00
abstract：:The relation is investigated between stimulus frequency, stimulus pulse amplitude and the neural damage induced by continuous stimulation of the cat's sciatic nerve. The chronically implanted electrodes were pulsed continuously and the effects of the electrical stimulation were quantified as the amount of early axonal...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02510526
更新日期：1995-05-01 00:00:00
abstract：:The tortuosity of retinal blood vessels is an important diagnostic indicator for a number of retinal pathologies. We applied robust quantitative tortuosity metrics, which are well suited to automated detection and measurement, to retinal fluorescein images of normal and diseased vessels exhibiting background diabetic ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-009-0559-4
更新日期：2010-01-01 00:00:00
abstract：:When the microvascular blood perfusion in human skin is measured by photoplethysmography (PPG), infra-red light (800-960 nm) is normally used as the light source. The PPG signal, which consists of a pulsatile (AC) and a slowly fluctuating (DC) component, was studied at different optical wavelengths utilising optical f...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02446295
更新日期：1991-01-01 00:00:00
abstract：:To describe upper airway obstruction in patients with sleep apnea syndrome, the steady state solutions of a simple model of local pharyngeal obstruction were studied. Importantly, the present model embodies a series of two individualised elements, each having its own compliance, which enables the consideration, from a...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02510972
更新日期：1997-11-01 00:00:00
abstract：:The aim of the study was to develop a method for investigating how interictal epileptic discharges in temporal epilepsy patients are activated spatially. The activity was measured using magneto-encephalography (MEG). The MEG data were used to produce a current-arrow map that reflected the topographic distribution of t...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02344215
更新日期：2002-05-01 00:00:00
abstract：:Musculoskeletal models have been developed to estimate internal loading on the human skeleton, which cannot directly be measured in vivo, from external measurements like kinematics and external forces. Such models of the shoulder and upper extremity have been used for a variety of purposes, ranging from understanding ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章,评审
doi：10.1007/s11517-013-1099-5
更新日期：2013-09-01 00:00:00
abstract：:Uniaxial stress-strain data were obtained from in vitro experiments on 20 porcine livers for compressions, elongations and cycles of compression and then elongation. There were about 70 cylindrical samples, with diameter 7mm and varying height (4-11 mm). The combined compression and elongation test provide a unified f...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02345212
更新日期：2004-11-01 00:00:00
abstract：:The heart rate variability (HRV) is an indicator of the subject homeostasis alterations. For a healthy individual, the HRV shows a nonlinear behavior, thus requiring a nonlinear approach to provide additional information about HRV dynamics. In this work, the nonlinear techniques, central tendency measure (CTM) and sec...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-015-1390-8
更新日期：2015-11-01 00:00:00
abstract：:Many successful models to describe the biomechanical characteristics of planar biological soft tissues are based on strain energy function. However, the parameters in these models are determined by biaxial extension test, which might be difficult to exercise for certain types of soft tissue. This study presents a new ...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-013-1098-6
更新日期：2013-10-01 00:00:00
abstract：:A method for accurately finding cardiac bidomain conductivity parameters is a crucial part of efforts to study and understand the electrical functioning of the heart. The bidomain model considers current flowing along (longitudinal) and across (transverse) sheets of cardiac fibres, as well as between these sheets (nor...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-013-1101-2
更新日期：2013-12-01 00:00:00
abstract：:The software system GASepo has been developed as a tool to visualise and analyse doping (searching for performance-enhancing drugs in sports) with recombinant erythropoietin (rEpo). Digital images derived from the separation of Epo isoforms in gels by iso-electric focusing followed by double blotting and chemiluminesc...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02345819
更新日期：2005-05-01 00:00:00
abstract：:The use of piezo-resistive uni-axial accelerometer signals in gait analysis is complicated by the fact that the measured signal is composed of different types of acceleration. The aim of the study is to obtain insight into the signal from a tangential accelerometer attached to the thigh during walking. Six subjects wa...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/BF02344868
更新日期：2000-11-01 00:00:00
abstract：:Mammography is a widely used screening tool and is the gold standard for the early detection of breast cancer. The classification of breast masses into the benign and malignant categories is an important problem in the area of computer-aided diagnosis of breast cancer. A small dataset of 57 breast mass images, each wi...
journal_title：Medical & biological engineering & computing
pub_type： 杂志文章
doi：10.1007/s11517-006-0077-6
更新日期：2006-08-01 00:00:00
