Dynamic time warping and machine learning for signal quality assessment of pulsatile signals.


:In this work, we describe a beat-by-beat method for assessing the clinical utility of pulsatile waveforms, primarily recorded from cardiovascular blood volume or pressure changes, concentrating on the photoplethysmogram (PPG). Physiological blood flow is nonstationary, with pulses changing in height, width and morphology due to changes in heart rate, cardiac output, sensor type and hardware or software pre-processing requirements. Moreover, considerable inter-individual and sensor-location variability exists. Simple template matching methods are therefore inappropriate, and a patient-specific adaptive initialization is therefore required. We introduce dynamic time warping to stretch each beat to match a running template and combine it with several other features related to signal quality, including correlation and the percentage of the beat that appeared to be clipped. The features were then presented to a multi-layer perceptron neural network to learn the relationships between the parameters in the presence of good- and bad-quality pulses. An expert-labeled database of 1055 segments of PPG, each 6 s long, recorded from 104 separate critical care admissions during both normal and verified arrhythmic events, was used to train and test our algorithms. An accuracy of 97.5% on the training set and 95.2% on test set was found. The algorithm could be deployed as a stand-alone signal quality assessment algorithm for vetting the clinical utility of PPG traces or any similar quasi-periodic signal.


Physiol Meas


Li Q,Clifford GD




Has Abstract


2012-09-01 00:00:00












  • Pulmonary perfusion measured by means of electrical impedance tomography.

    abstract::Electrical impedance tomography (EIT) is a recent imaging technique based on electrical impedance, offering the possibility of measuring pulmonary perfusion. In the present study the influence of several pulmonary haemodynamical parameters on the EIT signal were investigated. First, the influence on the systolic wave ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Vonk Noordegraaf A,Kunst PW,Janse A,Marcus JT,Postmus PE,Faes TJ,de Vries PM

    更新日期:1998-05-01 00:00:00

  • Wavelet bidomain sample entropy analysis to predict spontaneous termination of atrial fibrillation.

    abstract::The ability to predict if an atrial fibrillation (AF) episode terminates spontaneously or not through non-invasive techniques is a challenging problem of great clinical interest. This fact could avoid useless therapeutic interventions and minimize the risks for the patient. The present work introduces a robust AF pred...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Alcaraz R,Rieta JJ

    更新日期:2008-01-01 00:00:00

  • 3D reconstruction in electrical impedance imaging using a direct sensitivity matrix approach.

    abstract::This paper represents a reconstruction algorithm using a direct sensitivity matrix (DSM) approach for fast 3D image reconstruction in electrical impedance imaging. The boundary element method (BEM) is used in the construction of this matrix. The first images of a conductivity perturbation inside a sphere are reconstru...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Morucci JP,Granié M,Lei M,Chabert M,Marsili PM

    更新日期:1995-08-01 00:00:00

  • Repeatability of body sway measurements; day-to-day variation measured by sway magnetometry.

    abstract::The postural stability of 30 normal subjects in the age range 15 to 64 years was measured on five separate occasions, using the sway magnetometry technique, to determine the day-to-day repeatability of this measurement technique. On each occasion the pathlength and area enclosed by movement of the hips in a horizontal...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Elliott C,Murray A

    更新日期:1998-05-01 00:00:00

  • Phase shift between respiratory oscillations in cerebral blood flow velocity and arterial blood pressure.

    abstract::We aim to investigate whether phase shift between respiratory oscillations in cerebral blood flow velocity (CBFV) and arterial blood pressure (ABP) is associated with changes in cerebral autoregulation (CA) or reflects the mechano-elastic properties of the cerebrovascular bed. The relationships between respiratory pha...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Uryga A,Placek MM,Wachel P,Szczepański T,Czosnyka M,Kasprowicz M

    更新日期:2017-02-01 00:00:00

  • Characterization of cardiorespiratory phase synchronization and directionality in late premature and full term infants.

    abstract:OBJECTIVE:Though the mutual influence of cardiovascular and respiratory rhythms in healthy newborns has been documented, its full characterization is still pending. In general, the activity of many physiological subsystems has a well-expressed rhythmic character, and often an interdependency between physiological rhyth...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Lucchini M,Pini N,Fifer WP,Burtchen N,Signorini MG

    更新日期:2018-06-19 00:00:00

  • Early prediction of unexplained syncope by support vector machines.

    abstract::The goal of the present study was to develop and evaluate a new method for the prediction of unexplained syncope occurrences. Diagnosis of syncope is currently based on the reproduction of symptoms in combination with hypotension and bradycardia induced by a 45 min 60-70 degrees head-upright tilt test (HUTT). The main...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Schang D,Feuilloy M,Plantier G,Fortrat JO,Nicolas P

    更新日期:2007-02-01 00:00:00

  • Hemodynamic evaluation in pregnancy: limitations of impedance cardiography.

    abstract::Impedance cardiography (ICG) has been proposed to estimate the stroke volume (SV) and cardiac output (CO) in various medical indications. The aim of this study was to explore the reliability of ICG during pregnancy with respect to SV and CO measurements. Blood pressure, heart rate and thoracic impedance were monitored...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Moertl MG,Schlembach D,Papousek I,Hinghofer-Szalkay H,Weiss EM,Lang U,Lackner HK

    更新日期:2012-06-01 00:00:00

  • Chasing the evidence: the influence of data segmentation on estimates of dynamic cerebral autoregulation.

    abstract:OBJECTIVE:Transfer function analysis (TFA) of dynamic cerebral autoregulation (dCA) requires smoothing of spectral estimates using segmentation of the data (SD). Systematic studies are required to elucidate the potential influence of SD on dCA parameters. APPROACH:Healthy subjects (HS, n = 237) and acute ischaemic str...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Panerai RB,Intharakham K,Haunton V,Minhas JS,Llwyd O,Lam M,Salinet ASM,Nogueira RC,Katsogridakis E,Maggio P,Robinson TG

    更新日期:2020-04-17 00:00:00

  • Direct EIT Jacobian calculations for conductivity change and electrode movement.

    abstract::Electrical impedance tomography (EIT) is very sensitive to deformations of the medium boundary shape. For lung imaging, breathing and changes in posture move the electrodes and change the chest shape, resulting in image artefacts. Several approaches have been proposed to improve the reconstructed images; most methods ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Gómez-Laberge C,Adler A

    更新日期:2008-06-01 00:00:00

  • Feasible assessment of recovery and cardiovascular health: accuracy of nocturnal HR and HRV assessed via ring PPG in comparison to medical grade ECG.

    abstract:OBJECTIVE:To validate the accuracy of the Oura ring in the quantification of resting heart rate (HR) and heart rate variability (HRV). BACKGROUND:Wearable devices have become comfortable, lightweight, and technologically advanced for assessing health behavior. As an example, the novel Oura ring integrates daily physic...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Kinnunen H,Rantanen A,Kenttä T,Koskimäki H

    更新日期:2020-05-07 00:00:00

  • Solving the forward problem in electrical impedance tomography for the human head using IDEAS (integrated design engineering analysis software), a finite element modelling tool.

    abstract::If electrical impedance tomography is to be used as a clinical tool, the image reconstruction algorithms must yield accurate images of impedance changes. One of the keys to producing an accurate reconstructed image is the inclusion of prior information regarding the physical geometry of the object. To achieve this, ma...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Bayford RH,Gibson A,Tizzard A,Tidswell T,Holder DS

    更新日期:2001-02-01 00:00:00

  • A new method for measurement of gas exchange during anaesthesia using an extractable marker gas.

    abstract::A new method for the measurement of pulmonary gas exchange during inhalational anaesthesia is described which measures fresh gas and exhaust gas flows using carbon dioxide as an extractable marker gas. The theoretical precision of the method was compared by Monte Carlo modelling with other approaches which use marker ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Peyton PJ,Robinson GJ,Terry D,Junor PA

    更新日期:2004-02-01 00:00:00

  • Detection of animal tissue thickness using simple vertical electric sounding (VES).

    abstract::Tetrapolar linear arrays are commonly used in geophysics to explore the vertical distribution of resistivity values in a geological section of a specific point on the earth. This technique, known as vertical electric sounding (VES), uses different electrode configurations. For our experiments, we utilized its more pop...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Gonzalez CA,offniga O,Padilla LE

    更新日期:1997-02-01 00:00:00

  • Development of a novel method for assessing balance: the quantitative posturography system.

    abstract::Balance is the ability to maintain equilibrium while sitting or standing. There are a number of different methods which are used to assess balance: technical methods such as sway magnetometry, ataxia meter and force platforms, and clinical methods such as the functional reach test, Berg balance test and fall risk inde...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Browne J,O'Hare N

    更新日期:2000-11-01 00:00:00

  • An instrumented timed up and go: the added value of an accelerometer for identifying fall risk in idiopathic fallers.

    abstract::The Timed Up and Go (TUG) test is a widely used measure of mobility and fall risk among older adults that is typically scored using a stopwatch. We tested the hypothesis that a body-fixed accelerometer can enhance the ability of the TUG to identify community-living older adults with a relatively high fall risk of unkn...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Weiss A,Herman T,Plotnik M,Brozgol M,Giladi N,Hausdorff JM

    更新日期:2011-12-01 00:00:00

  • Coupling between arterial pressure, cerebral blood velocity, and cerebral tissue oxygenation with spontaneous and forced oscillations.

    abstract::We tested the hypothesis that transmission of arterial pressure to brain tissue oxygenation is low under conditions of arterial pressure instability. Two experimental models of hemodynamic instability were used in healthy human volunteers; (1) oscillatory lower body negative pressure (OLBNP) (N = 8; 5 male, 3 female),...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Rickards CA,Sprick JD,Colby HB,Kay VL,Tzeng YC

    更新日期:2015-04-01 00:00:00

  • Influence of tidal volume and positive end-expiratory pressure on ventilation distribution and oxygenation during one-lung ventilation.

    abstract:OBJECTIVE:The aim of the study was to explore the feasibility of titrating tidal volume (V T) and positive end-expiratory pressure (PEEP) during one-lung ventilation (OLV) based on ventilation distribution and oxygenation. APPROACH:Twenty-four consecutive patients requiring intubation with a double-lumen tube and subs...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Zhao Z,Wang W,Zhang Z,Xu M,Frerichs I,Wu J,Moeller K

    更新日期:2018-03-29 00:00:00

  • Non-invasive measurements of respiratory system mechanical properties by the forced oscillation technique in spontaneously breathing, mixed-breed, normal term lambs from birth to five months of age.

    abstract:OBJECTIVE:To provide a non-invasive approach to monitoring lung function in spontaneously breathing lambs, from birth to five months of life, by the forced oscillation technique (FOT). This report describes the experimental set-up, data processing, and identification of normal predicted values of resistance (Rrs) and r...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Veneroni C,Dahl MJ,Lavizzari A,Dawson E,Rebentisch A,Studstill S,Bowen S,Albertine KH,Dellaca RL

    更新日期:2019-11-04 00:00:00

  • PET(CO2) measurement and feature extraction of capnogram signals for extubation outcomes from mechanical ventilation.

    abstract::Capnography is a continuous and noninvasive method for carbon dioxide (CO2) measurement, and it has become the standard of care for basic respiratory monitoring for intubated patients in the intensive care unit. In addition, it has been used to adjust ventilatory parameters during mechanical ventilation (MV). However,...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Rasera CC,Gewehr PM,Domingues AM

    更新日期:2015-02-01 00:00:00

  • Multi-frequency imaging and modelling of respiratory related electrical impedance changes.

    abstract::Two studies concerning multi-frequency impedance measurements are presented. The first uses tetrapolar measurements made on the thorax and the second electrical impedance tomography images, also made from the thorax. The way in which the impedance and the changes in impedance with ventilation depend upon frequency are...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Brown BH,Barber DC,Wang W,Lu L,Leathard AD,Smallwood RH,Hampshire AR,Mackay R,Hatzigalanis K

    更新日期:1994-05-01 00:00:00

  • Empirical mode decomposition analysis of HRV data from patients undergoing local anaesthesia (brachial plexus block).

    abstract::Spectral analysis of heart rate variability (HRV) is used for the assessment of cardiovascular autonomic control. In this study, a data-driven adaptive technique called empirical mode decomposition (EMD) and the associated Hilbert spectrum has been used to evaluate the effect of local anaesthesia on HRV parameters in ...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Shafqat K,Pal SK,Kumari S,Kyriacou PA

    更新日期:2011-04-01 00:00:00

  • EITS changes following oleic acid induced lung water.

    abstract::We present the results of using electrical impedance tomographic spectroscopy (EITS) to follow the changes in lung water induced by oleic acid. Measurements were made on three goats before and after the injection of oleic acid. In addition to the EITs measurements, lung water was also measured using a double-indicator...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Brown BH,Flewelling R,Griffiths H,Harris ND,Leathard AD,Lu L,Morice AH,Neufeld GR,Nopp P,Wang W

    更新日期:1996-11-01 00:00:00

  • Reference values for whole body and cerebral multi-frequency bio-impedance data in neonates less than 12 h postpartum.

    abstract::Multiple frequency bio-electrical impedance analysis (MFBIA) may be useful for monitoring fluid balance in newborn infants or to provide early prediction of the outcome following perinatal asphyxia. A reference range of data is needed for identification of babies with abnormal impedance values. This was a cross-sectio...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Healy GN,Lingwood BE

    更新日期:2006-11-01 00:00:00

  • Topographic distribution of idiopathic pulmonary fibrosis: a hybrid physics- and agent-based model.

    abstract:OBJECTIVE:Idiopathic pulmonary fibrosis (IPF) is a progressive and fatal disease characterized by excessive deposition of collagen and associated stiffening of lung tissue. While it is known that inflammation and dysfunction of fibroblasts are involved in disease development, it remains poorly understood how cells and ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Wellman TJ,Mondoñedo JR,Davis GS,Bates JHT,Suki B

    更新日期:2018-06-28 00:00:00

  • The T-SCAN technology: electrical impedance as a diagnostic tool for breast cancer detection.

    abstract::In this paper we present the T-SCAN technology and its use as a diagnostic tool for breast cancer detection. We show, using theoretical models with simplified geometries, that displaying planar two-dimensional maps of the currents detected at the breast's surface relate to the electric field distribution within the br...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Assenheimer M,Laver-Moskovitz O,Malonek D,Manor D,Nahaliel U,Nitzan R,Saad A

    更新日期:2001-02-01 00:00:00

  • Classification of cognitive reserve in healthy older adults based on brain activity using support vector machine.

    abstract:OBJECTIVE:Cognitive reserve (CR) refers to the capacity of the brain to actively cope with damage via the implementation of remedial cognitive processes. Traditional CR measurements focus on static proxies, which may not be able to appropriately estimate dynamic changes in CR. This study therefore investigated the cogn...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Yang CY,Lin CP

    更新日期:2020-07-07 00:00:00

  • Monitoring of body fluid redistribution using segmental bioimpedance during rotation on a short-radius centrifuge.

    abstract:OBJECTIVE:The creation of artificial gravity on board a space station is one of the promising methods for preventing health problems during space missions; a short-radius centrifuge (SRC) is the model of such a method on Earth. Our goal was to evaluate the sensitivity of bioimpedance polysegmental measurements for moni...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Takhtobina YV,Shchelykalina SP,Smirnov YI,Smirnov AV,Koloteva MI,Vassilieva GY,Nikolaev DV

    更新日期:2020-05-07 00:00:00

  • Empirical estimators of gamma fits to tracer-dilution curves and their technical basis and practical scope.

    abstract::A gamma fit facilitates smoothing and extrapolation of distorted tracer-dilution curves in blood flow studies. Theoretically based empirical estimators were developed as simple alternatives to direct regression approaches from simulated gamma distributions with a wide range of shape asymmetry. Key curve features of pe...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Lopatatzidis A,Millard RK

    更新日期:2001-11-01 00:00:00

  • Triple-frequency method for measuring blood impedance.

    abstract::A method was developed for simultaneously measuring plasma resistance, cell interior resistance and cell membrane capacitance of blood. A three-element circuit model for simulating the impedance of blood was evaluated by comparing measured and calculated impedance frequency curves and was found feasible. The values of...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Zhao TX,Jacobson B,Ribbe T

    更新日期:1993-05-01 00:00:00