Abstract:
:Heart rate variability (HRV) is a well-accepted indicator for neural regulatory mechanisms in cardiovascular circulation. Its spectrum analysis provides the powerful means of observing the modulation between sympathetic and parasympathetic nervous system. The timescale of HRV is limited by discrete beat-to-beat time intervals; therefore, the exploration region of frequency band of HRV spectrum is relatively narrow. It had been proved that pulse rate variability (PRV) is a surrogate measurement of HRV in most of the circumstances. Moreover, arterial pulse wave contains small oscillations resulting from complex regulation of cardiac pumping function and vascular tone at higher frequency range. This study proposed a novel instantaneous PRV (iPRV) measurement based on Hilbert-Huang transform. Fifteen healthy subjects participated in this study and received continuous blood pressure wave recording in supine and passive head-up tilt. The result showed that the very-high-frequency band (0.4-0.9 Hz) varied during head-up tilt and had strong correlation (r = 0.77) with high-frequency band and medium correlation (r = 0.643) with baroreflex sensitivity. The very-high-frequency band of iPRV helps for the exploration of non-stationary autoregulation and provides the non-stationary spectral evaluation of HRV without distortion or information loss.
journal_name
Med Biol Eng Computjournal_title
Medical & biological engineering & computingauthors
Chang CC,Hsiao TC,Hsu HYdoi
10.1007/s11517-013-1135-5subject
Has Abstractpub_date
2014-04-01 00:00:00pages
343-51issue
4eissn
0140-0118issn
1741-0444journal_volume
52pub_type
杂志文章abstract::Induction coils were fabricated based on flexible printed circuit board for inductive transcutaneous power transmission. The coil had closed magnetic circuit (CMC) structure consisting of inner and outer magnetic core. The power transmission efficiency of the fabricated device was measured in the air and in vivo condi...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-012-0939-z
更新日期:2012-09-01 00:00:00
abstract::The present study describes a new methodological approach which allows the separate analysis and quantitative determination of the viscous and elastic components of human hair using a computerised experimental system. In a first series of experiments subsequent to the estimation of the cross-sectional surface area of ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02446198
更新日期:1992-01-01 00:00:00
abstract::The reconstruction of bioluminescence tomography (BLT) is severely ill-posed due to the insufficient measurements and diffuses nature of the light propagation. Predefined permissible source region (PSR) combined with regularization terms is one common strategy to reduce such ill-posedness. However, the region of PSR i...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-018-1842-z
更新日期:2018-11-01 00:00:00
abstract::Dynamic methods in the spectral domain are necessary to analyse biological signals because of the frequently nonstationary character of the signals. The paper presents an adaptive procedure of fitting time-dependent ARMA models to nonstationary signals, which is suitable for on-line calculations. The properties of the...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02510536
更新日期:1995-05-01 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::In the PREVENIR-5 study, artificial neural networks (NN) were applied to a large sample of patients with recent first acute coronary syndrome (ACS) to identify determinants of persistence of evidence-based cardiovascular medications (EBCM: antithrombotic + beta-blocker + statin + angiotensin converting enzyme inhibito...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-011-0785-4
更新日期:2011-08-01 00:00:00
abstract::Currently, simulations of the induced currents in the brain produced by transcranial magnetic stimulation (TMS) are used to elucidate the regions reached by stimuli. However, models commonly found in the literature are too general and neglect imperfections in the windings. Aiming to predict the stimulation sites in pa...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-020-02156-2
更新日期:2020-07-01 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::Precise segmentation of stroke lesions from brain magnetic resonance (MR) images poses a challenging task in automated diagnosis. In this paper, we proposed a new method called watershed-based lesion segmentation algorithm (WLSA), which is a novel intensity-based segmentation technique used to delineate infarct lesion...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-017-1726-7
更新日期:2018-05-01 00:00:00
abstract::Blood oxygenation level is an important measure that can be used alongside functional magnetic resonance imaging data in order to obtain closer correlates of neuronal activation. A robust estimate of this measure has thus far not been demonstrated. This is mainly due to the lack of knowledge of the underlying paramete...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-012-0886-8
更新日期:2012-05-01 00:00:00
abstract::In vivo follow-up of muscle shape variation represents a challenge when evaluating muscle development due to disease or treatment. Recent developments in muscles reconstruction techniques indicate MRI as a clinical tool for the follow-up of the thigh muscles. The comparison of 3D muscles shape from two different seque...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-015-1302-y
更新日期:2015-10-01 00:00:00
abstract::While matrix remodeling plays a key role in vascular physiology and pathology, the underlying mechanisms have remained incompletely understood. We studied the remodeling of collagen matrices by individual vascular smooth muscle cells (SMCs), clusters and monolayers. In addition, we focused on the contribution of trans...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-012-0916-6
更新日期:2012-07-01 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::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::The management of postprandial glucose excursions in type 1 diabetes has a major impact on overall glycaemic control. In this work, we propose and evaluate various mechanistic models to characterize the disposal of meal-attributable glucose. Sixteen young volunteers with type 1 diabetes were subject to a variable-targ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-016-1509-6
更新日期:2017-02-01 00:00:00
abstract::Whether Fourier transform infra-red spectroscopy with an attenuated total reflection prism could be applied for noninvasive glucose measurement through oral mucosa was evaluated. As a result, the same absorbance peak at 1033 cm-1 as in glucose aqueous solution was found in the absorbance spectra through mucous membran...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02446645
更新日期:1993-07-01 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::In a previous paper we demonstrated that the linear portion of the pressure-velocity loop (PU-loop) corresponding to early systole could be used to calculate the local wave speed. In this paper we extend this work to show that determination of the time at which the PU-loop first deviates from linearity provides a conv...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-007-0241-7
更新日期:2007-12-01 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::In this paper, the limitations of the conventional formula for the computation of peripheral blood flow from impedance plethysmograms are highlighted, and a correction to the formula is suggested. A conductivity cell experiment is described to show the dependence of the value of the blood flow index (BFI), obtained fr...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02524237
更新日期:1994-11-01 00:00:00
abstract::Electrical and mechanical stimulation of the oesophagus has been recently proposed to examine the physiological effects of autonomic stimulation in humans. Cortical evoked potentials (EPs) to oesophageal stimulation provide an assessment of afferent fibres and central processing. However, habituation takes place durin...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/BF02534088
更新日期:1997-07-01 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::In this study, the shape and the configuration of smooth muscle cells (SMCs) within the arterial wall are altered to investigate their influence on molecular transport across the media layer of the thoracic aorta wall. In a 2D geometry of the media layer containing SMCs, the finite-element method has been employed to ...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-007-0219-5
更新日期:2007-11-01 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::Aortic stiffness measurement is well recognized as an independent predictor of cardiovascular mortality and morbidity. Recently, a simple method has been proposed for the evaluation of the local aortic stiffness (AoStiff) using a non-invasive bioelectrical impedance (BI) technique. This approach relies on a novel inte...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-011-0741-3
更新日期:2011-04-01 00:00:00
abstract::This study examined the electroencephalogram functional connectivity (coherence) and effective connectivity (flow of information) of selected brain regions during three different attentive states: awake, meditation and drowsiness. For the estimation of functional connectivity (coherence), Welch and minimum variance di...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-015-1272-0
更新日期:2015-07-01 00:00:00
abstract::Biological variation in branching patterns is likely to affect perfusion of tissue. To assess the fundamental consequences of branching characteristics, 50 stochastic asymmetrical coronary trees and one non-stochastic symmetrical branching tree were generated. In the stochastic trees, area growth, A, at branching poin...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-006-0139-9
更新日期:2007-01-01 00:00:00
abstract::In this study, we propose an integrated tooth segmentation and gingival tissue deformation simulation framework used to design and evaluate the orthodontic treatment plan especially with invisible aligners. Firstly, the bio-characteristics information of the digital impression is analyzed quantitatively and demonstrat...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-020-02230-9
更新日期:2020-10-01 00:00:00
abstract::The flow mechanisms that play a role on aerosol deposition were identified and presented in a companion paper (Timothy et al. in Med Biol Eng Comput. doi: 10.1007/s11517-015-1407-3 , 2015). In the current paper, the effects of invasive conventional mechanical ventilation waveforms and endotracheal tube (ETT) on the ae...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-015-1408-2
更新日期:2016-07-01 00:00:00
abstract::The surface electroenterogram (EEnG) is a non-invasive method of studying myoelectrical bowel activity. However, surface EEnG recordings are contaminated by cardiac activity, respiratory and motion artifacts, and other sources of interference. The aim of this work is to remove the respiration artifact and the very low...
journal_title:Medical & biological engineering & computing
pub_type: 杂志文章
doi:10.1007/s11517-007-0189-7
更新日期:2007-06-01 00:00:00