3,084 results match your criteria Physiological measurement[Journal]


Association between physiological stress and skin temperature response after a half marathon.

Physiol Meas 2019 Mar 14. Epub 2019 Mar 14.

Department of Physiology, Universitat de Valencia, Valencia, Comunitat Valenciana, SPAIN.

Objective: The objective of this study was to determine the association between skin temperature response and the physiological stress after a half marathon.

Approach: Seventeen runners were measured 48 h before, 24 h before, 24 h after and 48 h after completing a half marathon. The measurements on each day of testing included blood markers (creatine kinase [CK] and glutamate oxaloacetate transaminase [GOT]), perception of pain and fatigue (using a visual analogue scale), skin temperature (using infrared thermography), and jump performance (using countermovement jump test). Read More

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http://dx.doi.org/10.1088/1361-6579/ab0fdcDOI Listing
March 2019
1 Read

Compressive sensing in electrical impedance tomography for breathing monitoring.

Physiol Meas 2019 Mar 7. Epub 2019 Mar 7.

Department of Electronic and Electrical Engineering, University College London, Torrington Place, LONDON, WC1E 7JE, London, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

Objective: Continuous functional thorax monitoring using EIT has been extensively researched. A limiting factor in high temporal resolution, three dimensional, and fast EIT is the handling of the volume of raw impedance data produced for transmission and storage. Owing to the periodicity of breathing that may be reflected in EIT boundary measurements, data dimensionality may be reduced efficiently at the time of sampling using compressed sensing techniques. Read More

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http://iopscience.iop.org/article/10.1088/1361-6579/ab0daa
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http://dx.doi.org/10.1088/1361-6579/ab0daaDOI Listing
March 2019
1 Read

Remote timed up and go evaluation from activities of daily living reveals changing mobility after surgery.

Physiol Meas 2019 Mar 6. Epub 2019 Mar 6.

Philips Research, Eindhoven, North Brabant, NETHERLANDS.

Background: Mobility impairment is common in older adults and influences negatively the quality of life. Mobility may changes rapidly following hospital discharge. The Timed Up and Go test (TUG) is often used to assess functional mobility; however, because TUG may require supervision from a trained clinician, assessments may be infrequent. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0d3eDOI Listing
March 2019
1 Read

High-pressure blood flow restriction with very low load resistance training results in peripheral vascular adaptations similar to heavy resistance training.

Physiol Meas 2019 Mar 6. Epub 2019 Mar 6.

University of Mississippi, University, UNITED STATES.

Objective: To investigate vascular adaptations to eight weeks of resistance exercise, with and without different pressures of blood flow restriction (BFR), in the upper and lower body.

Approach: Forty individuals (men=20, women=20) completed eight weeks of resistance exercise at very low loads (15% of one-repetition maximum (1RM)), with two levels of BFR (40% arterial occlusion pressure (AOP), 80% AOP), without BFR, and 70% of 1RM. Vascular conductance and venous compliance were measured via plethysmography before and following training in the forearms and in the calves. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0d2aDOI Listing

Investigating the safety of fast neural electrical impedance tomography in the rat brain.

Physiol Meas 2019 Mar 6. Epub 2019 Mar 6.

Department of Medical Physics and Bioengineering, University College London, London, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

Objective: Electrical Impedance Tomography (EIT) can be used to image impedance changes which arise due to fast electrical activity during neuronal depolarisation and so holds therapeutic potential for improving the localisation of epileptic seizure foci in patients with treatment-resistant epilepsy to aid surgical resection of epileptogenic tissue. Prolonged cortical stimulation may, however, induce neural injury through excitotoxicity and electrochemical reactions at the tissue-electrode interface. The purpose of this work was to assess whether current levels used in fast neural EIT studies induce histologically detectable tissue damage when applied continuously to the rat cerebral cortex. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0d53DOI Listing

Noise-robust bioimpedance approach for cardiac output measurement.

Physiol Meas 2019 Mar 6. Epub 2019 Mar 6.

Dartmouth College, Hanover, New Hampshire, UNITED STATES.

Objective: Congestive heart failure is a problem effecting millions of Americans. A continuous, non-invasive, telemonitoring device that can accurately monitor cardiac metrics could greatly help this population, reducing unnecessary hospitalizations and cost.

Approach: Machine Learning (ML) algorithms trained on electrical-impedance tomography (EIT) data are presented for portable cardiac monitoring. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0d45DOI Listing
March 2019
1 Read

Information-domain method for the quantification of the complexity of the sympathetic baroreflex regulation in healthy subjects and amyotrophic lateral sclerosis patients.

Physiol Meas 2019 Mar 6. Epub 2019 Mar 6.

Department of Biomedical Sciences for Health, University of Milan, Milan, ITALY.

Background: The sympathetic baroreflex (sBR) adjusts muscle sympathetic nerve activity (MSNA) in response to arterial pressure changes but the relevance of assessing sBR control complexity is unclear.

Objective: We propose a method for the evaluation of sBR control complexity.

Approach: The approach comprises the quantification of complexity of the sBR latency regulation and the assessment of complexity of the relationship linking MSNA burst to R-wave peak regardless of the variability of the sBR latency. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0d4bDOI Listing
March 2019
2 Reads

Current conveyor based wide-band current driver for electrical impedance tomography.

Physiol Meas 2019 Mar 4. Epub 2019 Mar 4.

Dartmouth College, Hanover, New Hampshire, UNITED STATES.

In this paper a wide-band integrated current driver for electrical impedance tomography (EIT) is presented. The application is primarily for prostate and breast cancer detection which require the tissue to be interrogated at frequencies up to 10 MHz while achieving low harmonic distortion and high accuracy. The current driver is based on current conveyor architecture and can deliver 1. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0c3cDOI Listing

Extracting impedance changes from a frequency multiplexed signal during neural activity in sciatic nerve of rat: preliminary study in-vitro.

Physiol Meas 2019 Mar 4. Epub 2019 Mar 4.

Mechanical Engineering, The University of Auckland, Auckland, Auckland, NEW ZEALAND.

Objective: Establish suitable frequency spacing and demodulation steps to use when extracting impedance changes from frequency division multiplexed (FDM) carrier signals in peripheral nerve. Approach: Experiments were performed in-vitro on cadavers immediately following euthanasia. Neural activity was evoked via stimulation of nerves in the hind paw, while carrier signals were injected, and recordings obtained, with a dual ring nerve cuff implanted on the sciatic nerve. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0c24DOI Listing

Simultaneous EIT and EEG using frequency division multiplexing.

Physiol Meas 2019 Mar 1. Epub 2019 Mar 1.

Department of Medical Physics and Bioengineering, University College London, London, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

Objective: Methods have previously been reported for simultaneous EIT and EEG recording, but these have relied on post-hoc signal processing to remove switching artefacts from the EEG signal and require dedicated hardware filters and the use of separate EEG and EIT electrodes. This work aims to demonstrate that an uncorrupted EEG signal can be collected simultaneously with EIT data by using frequency division multiplexing (FDM), and to show that the EIT data provides useful information when compared to EEG source localisation. Approach: A custom FDM EIT current source was created and evaluated in resistor phantom and neonatal head tank experiments, where a static and dynamic perturbation was imaged. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0bbcDOI Listing
March 2019
1 Read

Reconstruction algorithm for frequency-differential EIT using absolute values.

Physiol Meas 2019 Feb 28. Epub 2019 Feb 28.

Chair for Medical Information Technology, Rheinisch - Westfalische Technische Hochschule Aachen, Aachen, GERMANY.

Objective: Tissues in the body differ by their frequency-dependent conductivity. Frequency-differential Electrical Impedance Tomography (fdEIT) is a promising technique to reconstruct the distribution of tissue inside the body by injecting current at two frequencies and measuring the resulting surface-potential.

Approach: The Gauss-Newton method is one way to map the surface measurements to a conductivity image. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0b55DOI Listing
February 2019
1 Read

Estimation of respiratory variables from thoracoabdominal breathing distance: a review of different techniques and calibration methods.

Physiol Meas 2019 Feb 28. Epub 2019 Feb 28.

Département Sciences du sport et éducation physique, Ecole normale supérieure de Rennes, Campus de Ker Lann, Avenue Robert Schuman , 35170 Bruz, FRANCE.

The precise measurement of respiratory variables, such that tidal volume, minute ventilation, respiratory rate is necessary to monitor respiratory status to overcome several diseases, improve patient health conditions and reduce health care costs. This measurement has conventionally been performed by breathing into a mouthpiece connected to a flow rate measuring device. However, a mouthpiece is uncomfortable for the subject and it is difficult to use for long term monitoring. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0b63DOI Listing
February 2019
1 Read

Fetal magnetocardiogram waveform characteristics.

Physiol Meas 2019 Feb 25. Epub 2019 Feb 25.

Department of Medical Physics, University of Wisconsin Madison, Madison, Wisconsin, UNITED STATES.

Background: Fetal magnetocardiography (fMCG) is the most direct and precise method of assessing fetal rhythm and conduction. Although the utility of fMCG for evaluation of fetuses with serious arrhythmia is generally acknowledged, many aspects fetal rhythm and conduction are relatively unstudied. Objective: To record fMCG in a large group of normal fetuses in order to provide a more comprehensive evaluation of fMCG waveform characteristics, including waveform intervals, amplitudes, and morphology. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0a2cDOI Listing
February 2019
1 Read

Effect of dispersion in nerve on compound action potential and impedance change: a modelling study.

Physiol Meas 2019 Feb 20. Epub 2019 Feb 20.

Department of Medical Physics and Bioengineering, University College London, London, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND.

Objective: Electrical impedance tomography (EIT) is capable of imaging fast compound electrical activity (Compound Action Potentials, or CAPs) inside peripheral nerves. The ability of EIT to detect impedance changes (dZ) which arise from the opening of ion channels during the CAP is limited by the dispersion with distance from the site of onset, as fibres have differing conduction velocities. The effect is largest for autonomic nerves mainly formed of slower conducting unmyelinated fibres where signals cannot be recorded more than a few cm away from the stimulation. Read More

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http://dx.doi.org/10.1088/1361-6579/ab08ceDOI Listing
February 2019

Bi-frequency symmetry difference electrical impedance tomography - a novel technique for perturbation detection in static scenes.

Physiol Meas 2019 Feb 20. Epub 2019 Feb 20.

Electrical and Electronic Engineering, National University of Ireland - Galway, Galway, Galway, IRELAND.

Objective: A novel method for the imaging of static scenes using Electrical Impedance Tomography (EIT) is reported with implementation and validation using numerical and phantom models. The technique is applicable to regions featuring symmetry in the normal case, asymmetry in the presence of a perturbation, and where there is a known, frequency-dependent change in the electrical conductivity of the materials in the region.

Methods: The stroke diagnostic problem is used as a motivating sample application. Read More

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http://dx.doi.org/10.1088/1361-6579/ab08baDOI Listing
February 2019

Corrigendum: Predicting spirometry readings using cough sound features and regression (2018 Physiol. Meas. 39 095001).

Physiol Meas 2019 Feb 13. Epub 2019 Feb 13.

Princess Margaret Hospital, Perth, AUSTRALIA.

The purpose of this submission is to provide missing information to complete the conflict of interest statement associated with the article. The statements provided here augment the already provided information rather than replace it. Read More

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http://dx.doi.org/10.1088/1361-6579/ab06ceDOI Listing
February 2019
1 Read

Multi-day, multi-sensor ambulatory monitoring of gastric electrical activity.

Physiol Meas 2019 Mar 1;40(2):025011. Epub 2019 Mar 1.

Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand. Department of Surgery, University of Auckland, Auckland, New Zealand.

Objective: Bioelectrial signals known as slow waves play a key role in coordinating gastric motility. Slow wave dysrhythmias have been associated with a number of functional motility disorders. However, there have been limited human recordings obtained in the consious state or over an extended period of time. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0668DOI Listing
March 2019
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The validity of the EMG and MMG techniques to examine muscle hypertrophy.

Physiol Meas 2019 Mar 13;40(2):025009. Epub 2019 Mar 13.

Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, 110 Ruth Leverton Hall, Lincoln, NE 68583-0806, United States of America. Author to whom any correspondence should be addressed.

Objective: The purpose of this investigation was to examine the ability of the electromyographic (EMG) and mechanomyographic (MMG) amplitude versus torque relationships to track group and individual changes in muscle hypertrophy as a result of resistance training.

Approach: Twelve women performed four weeks of forearm flexion blood flow restriction (BFR) resistance training at a frequency of three times per week. The training was performed at an isokinetic velocity of 120° · s with a training load that corresponded to 30% of concentric peak torque. Read More

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http://dx.doi.org/10.1088/1361-6579/ab057eDOI Listing
March 2019
1 Read

Handrail support produces a higher rate pressure product in apparently healthy non-treadmill users during maximal exercise testing.

Physiol Meas 2019 Feb 26;40(2):02NT01. Epub 2019 Feb 26.

Cardiac Investigations Unit, Logan Hospital, Meadowbrook, Australia. Menzies Health Institute, Queensland, Australia. School of Human Movement and Nutrition Sciences, University of Queensland, Brisbane, Australia. School of Allied Health Sciences, Griffith University, Gold Coast, Australia. Cardiac Investigations Unit, Logan Hospital, PO Box 6031, Yatala, Queensland 4207, Australia. Author to whom any correspondence should be addressed.

Objective: Exercise treadmill testing (ETT) is a well-established procedure for the diagnosis, prognosis and functional assessment of patients with suspected cardiovascular disease. The use of handrail support during ETT is often discouraged as this has been demonstrated to overestimate functional capacity. It is unknown if this increase in functional capacity translates to an increase in cardiac workload. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0565DOI Listing
February 2019

Non-invasive machine learning estimation of effort differentiates sleep-disordered breathing pathology.

Physiol Meas 2019 Feb 26;40(2):025008. Epub 2019 Feb 26.

Stanford Center for Sleep Sciences and Medicine, Stanford University, 3165 Porter Drive, MC 5480, Palo Alto, CA 94304-5480, United States of America. Danish Center for Sleep Medicine, Department of Clinical Neurophysiology, Rigshospitalet, University of Copenhagen, Glostrup, Denmark. Biomedical Engineering, Department of Electrical Engineering, Technical University of Denmark, Kongens Lyngby, Denmark.

Objective: Obstructive sleep-disordered breathing (SDB) events, unlike central events, are associated with increased respiratory effort. Esophageal pressure (P ) monitoring is the gold standard for measuring respiratory effort, but it is typically poorly tolerated because of its invasive nature. The objective was to investigate whether machine learning can be applied to routinely collected non-invasive, polysomnography (PSG) measures to accurately model peak negative P . Read More

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http://dx.doi.org/10.1088/1361-6579/ab0559DOI Listing
February 2019
1 Read

Autonomic impairment in Alzheimer's disease is revealed by complexity analysis of functional thermal imaging signals during cognitive tasks.

Physiol Meas 2019 Feb 8. Epub 2019 Feb 8.

Neuroscience, Imaging and Clinical Science, Universita degli Studi Gabriele d\'Annunzio Chieti e Pescara, Chieti, Chieti, ITALY.

Alzheimer's disease (AD) is characterized by progressive memory failures and visuo-spatial impairment. Moreover, AD can be accompanied by autonomic system alterations, which, among others, affect thermoregulatory activity. We here investigated differences in autonomic activity between AD patients and healthy controls (HC) employing a complexity analysis of functional infrared imaging (fIRI) data acquired at rest and during the execution of clinical cognitive and mnemonic tests. Read More

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http://dx.doi.org/10.1088/1361-6579/ab057dDOI Listing
February 2019

Posture effects on the calibratability of remote pulse oximetry in visible light.

Physiol Meas 2019 Feb 7. Epub 2019 Feb 7.

Research, Philips, High Tech Campus 36, 5656AE Eindhoven, Eindhoven, 5656AE, NETHERLANDS.

Objective: Remote pulse oximetry in visible light (VIS) is a relevant application of photoplethysmography (PPG). However, wavelengths penetrate at different depths and VIS-based pulse oximetry may not guarantee robustness to physiological variations of the skin properties. This paper shows how a simple manoeuver like a posture change can hamper the accuracy of a method relying on red and the less penetrating green wavelengths. Read More

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http://dx.doi.org/10.1088/1361-6579/ab051aDOI Listing
February 2019

An open access database for the evaluation of respiratory sound classification algorithms.

Physiol Meas 2019 Feb 1. Epub 2019 Feb 1.

Center for Informatics and Systems, University of Coimbra, Pólo II, 3030-290, Coimbra, COIMBRA, PORTUGAL.

Background And Objectives: During the last decades, there has been a significant interest in the automatic analysis of respiratory sounds. However, currently there are no publicly available large databases with which new algorithms can be evaluated and compared. Further developments in the field are dependent on the creation of such databases. Read More

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http://dx.doi.org/10.1088/1361-6579/ab03eaDOI Listing
February 2019

An open source autocorrelation-based method for fetal heart rate estimation from one-dimensional Doppler ultrasound.

Physiol Meas 2019 Feb 26;40(2):025005. Epub 2019 Feb 26.

Department of Biomedical Informatics, Emory University, Atlanta, GA, United States of America.

Objective: Open research on fetal heart rate (FHR) estimation is relatively rare, and evidence for the utility of metrics derived from Doppler ultrasound devices has historically remained hidden in the proprietary documentation of commercial entities, thereby inhibiting its assessment and improvement. Nevertheless, recent studies have attempted to improve FHR estimation; however, these methods were developed and tested using datasets composed of few subjects and are therefore unlikely to be generalizable on a population level. The work presented here introduces a reproducible and generalizable autocorrelation (AC)-based method for FHR estimation from one-dimensional Doppler ultrasound (1D-DUS) signals. Read More

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http://dx.doi.org/10.1088/1361-6579/ab033dDOI Listing
February 2019

Estimating blood pressure trends and the nocturnal dip from photoplethysmography.

Physiol Meas 2019 Feb 26;40(2):025006. Epub 2019 Feb 26.

Personal Health, Philips Research, Royal Philips, Eindhoven, The Netherlands. Signal Processing Systems, Electrical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.

Objective: Evaluate a method for the estimation of the nocturnal systolic blood pressure (SBP) dip from 24 h blood pressure trends using a wrist-worn photoplethysmography (PPG) sensor and a deep neural network in free-living individuals, comparing the deep neural network to traditional machine learning and non-machine learning baselines.

Approach: A wrist-worn PPG sensor was worn by 106 healthy individuals for 226 d during which 5111 reference values for blood pressure (BP) were obtained with a 24 h ambulatory BP monitor and matched with the PPG sensor data. Features based on heart rate variability and pulse morphology were extracted from the PPG waveforms. Read More

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http://dx.doi.org/10.1088/1361-6579/ab030eDOI Listing
February 2019

Application of infrared thermography in diagnosing peripherally inserted central venous catheter infections in children with cancer.

Physiol Meas 2019 Jan 30. Epub 2019 Jan 30.

Pediatrics Department, Hospital Clínico Universitario de Valencia, Valencia, Comunidad Valenciana, SPAIN.

Children affected by oncological diseases are often fitted with central venous catheters. Catheter infection is a frequent complication, sometimes accompanied by thrombosis. We designed a case/control-type pilot study of children with oncological diseases fitted with a central venous catheter. Read More

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http://dx.doi.org/10.1088/1361-6579/ab031aDOI Listing
January 2019
1 Read

Predicting forced vital capacity (FVC) using support vector regression (SVR).

Physiol Meas 2019 Mar 1;40(2):025010. Epub 2019 Mar 1.

Institute of Electronics, Chinese Academy of Sciences, Beijing, People's Republic of China. University of Chinese Academy of Sciences, Beijing, People's Republic of China.

Objective: Spirometry, as the gold standard approach in the diagnosis of chronic obstructive pulmonary disease (COPD), has strict end of test (EOT) criteria (e.g. complete exhalation), which cannot be met by patients with compromised health states. Read More

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http://dx.doi.org/10.1088/1361-6579/ab031cDOI Listing
March 2019
1 Read

Eye-tracker algorithms to detect saccades during static and dynamic tasks: a structured review.

Physiol Meas 2019 Feb 26;40(2):02TR01. Epub 2019 Feb 26.

Department of Neurology, Oregon Health and Science University, Portland, OR, United States of America.

Objective: Eye-tracking devices have become widely used as clinical assessment tools in a variety of applied-scientific fields to measure saccadic eye movements. With the emergence of multiple static and dynamic devices, the concurrent need for algorithm development and validation is paramount.

Approach: This review assesses the prevalence of current saccade detection algorithms, their associated validation methodologies and the suitability of their application. Read More

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http://dx.doi.org/10.1088/1361-6579/ab02abDOI Listing
February 2019

Detection of atrial fibrillation using a wrist-worn device.

Physiol Meas 2019 Feb 22;40(2):025003. Epub 2019 Feb 22.

Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania.

Objective: This study proposes an algorithm for the detection of atrial fibrillation (AF), designed to operate on extended photoplethysmographic (PPG) signals recorded using a wrist-worn device of own design.

Approach: Robustness against false alarms is achieved by means of signal quality assessment and different techniques for suppression of ectopic beats, bigeminy, and respiratory sinus arrhythmia. The decision logic is based on our previously proposed RR interval-based AF detector, but modified to account for differences between interbeat intervals in the ECG and the PPG. Read More

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http://dx.doi.org/10.1088/1361-6579/ab029cDOI Listing
February 2019

Video and audio processing in paediatrics: a review.

Physiol Meas 2019 Feb 26;40(2):02TR02. Epub 2019 Feb 26.

Univ Rennes, CHU Rennes, INSERM, LTSI - UMR 1099, F-35000 Rennes, France. Voxygen, F-22560 Pleumeur-Bodou, France.

Objective: Video and sound acquisition and processing technologies have seen great improvements in recent decades, with many applications in the biomedical area. The aim of this paper is to review the overall state of the art of advances within these topics in paediatrics and to evaluate their potential application for monitoring in the neonatal intensive care unit (NICU).

Approach: For this purpose, more than 150 papers dealing with video and audio processing were reviewed. Read More

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http://dx.doi.org/10.1088/1361-6579/ab0096DOI Listing
February 2019
7 Reads

Optimal fiducial points for pulse rate variability analysis from forehead and finger photoplethysmographic signals.

Physiol Meas 2019 Feb 26;40(2):025007. Epub 2019 Feb 26.

Biomedical Signal Interpretation and Computational Simulation (BSICoS) Group, Aragon Institute of Engineering Research (I3A), IIS Aragon,University of Zaragoza, Zaragoza, Spain. Centro de Investigacion Biomedica en Red-Bioingenieria, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain.

Objective: The aim of this work is to evaluate and compare five fiducial points for the temporal location of each pulse wave from forehead and finger photoplethysmographic (PPG) pulse wave signals to perform pulse rate variability (PRV) analysis as a surrogate for heart rate variability (HRV) analysis.

Approach: Forehead and finger PPG signals were recorded during a tilt-table test simultaneously with the electrocardiogram (ECG). Artefacts were detected and removed and five fiducial points were computed: apex, middle-amplitude and foot points of the PPG signal, apex point of the first derivative signal and the intersection point of the tangent to the PPG waveform at the apex of the derivative PPG signal and the tangent to the foot of the PPG pulse, defined as the intersecting tangents method. Read More

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http://iopscience.iop.org/article/10.1088/1361-6579/ab009b
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http://dx.doi.org/10.1088/1361-6579/ab009bDOI Listing
February 2019
11 Reads

The influence of posture on parasternal intercostal muscle activity in healthy young adults.

Physiol Meas 2019 Feb 1;40(1):01NT03. Epub 2019 Feb 1.

Centre for Human & Applied Physiological Sciences, School of Basic & Medical Biosciences, King's College London, London, United Kingdom. Equal contribution to the study.

Objective: Parasternal intercostal muscle electromyography (EMGpara) has been used as an index of respiratory load in health and disease. While reference values are available, such data have been obtained with subjects in the seated position only. The objective of the current study was to determine the influence of posture on measurements of EMGpara. Read More

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http://dx.doi.org/10.1088/1361-6579/aafefdDOI Listing
February 2019
6 Reads

Relevance of evaluating the rate of torque development in ballistic contractions of submaximal amplitude.

Physiol Meas 2019 Feb 15;40(2):025002. Epub 2019 Feb 15.

Department of Medical Sciences, NeuroMuscularFunction Research Group, School of Exercise & Sport Sciences, University of Turin, Turin, Italy.

Objective: The neuromuscular quickness capacity can be assessed by calculating the rate of torque development (RTD) during ballistic contractions of maximal (RTD) or submaximal (RTD) amplitudes. In a series of ballistic contractions of submaximal amplitudes, the RTD scaling factor (RTD-SF) represents the slope of the linear regression between achieved peak torques and the corresponding RTD. First we investigated whether the RTD-SF contributes to the prediction, together with maximal voluntary torques (MVT), of the RTD. Read More

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http://dx.doi.org/10.1088/1361-6579/aaff24DOI Listing
February 2019
1 Read

Objective evaluation of bradykinesia in Parkinson's disease using an inexpensive marker-less motion tracking system.

Physiol Meas 2019 Feb 1;40(1):014004. Epub 2019 Feb 1.

Bionics Institute, East Melbourne, Victoria, Australia.

Objective: Quantification of bradykinesia (slowness of movement) is crucial for the treatment and monitoring of Parkinson's disease. Subjective observational techniques are the de-facto 'gold standard', but such clinical rating scales suffer from poor sensitivity and inter-rater variability. Although various technologies have been developed for assessing bradykinesia in recent years, most still require considerable expertise and effort to operate. Read More

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http://dx.doi.org/10.1088/1361-6579/aafef2DOI Listing
February 2019
1 Read

Detection of atrial fibrillation and other abnormal rhythms from ECG using a multi-layer classifier architecture.

Physiol Meas 2019 Jan 16. Epub 2019 Jan 16.

Tata Consultancy Services Ltd, Delhi, INDIA.

Atrial Fibrillation (AF) and other types of abnormal heart rhythms are related to multiple fatal cardiovascular diseases that impact the quality of human life. Hence, the development of an automated robust method that can reliably detect AF in addition to other non-sinus and sinus rhythms can aid in better dispersion of medical care. The present study focuses on developing an algorithm for classification of short, single lead Electrocardiogram (ECG) recordings into <i>normal</i>, <i>AF</i>, <i>other</i> abnormal rhythms and <i>noisy </i>classes. Read More

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http://iopscience.iop.org/article/10.1088/1361-6579/aaff04
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http://dx.doi.org/10.1088/1361-6579/aaff04DOI Listing
January 2019
6 Reads

Concussion history associated with increased postural control deficits after subsequent injury.

Physiol Meas 2019 Feb 20;40(2):024001. Epub 2019 Feb 20.

School of Community Health Sciences, University of Nevada, Reno, NV, United States of America. Author to whom any correspondence should be addressed.

Objective: Postural control deficits have been extensively reported following sport-related concussions. Concussed athletes demonstrate these deficits as early as 24 h post-concussion and may persist for up to six months. Many of these prior studies have included mixed samples with prior injury history that may affect the postural control data. Read More

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http://dx.doi.org/10.1088/1361-6579/aafcd8DOI Listing
February 2019
16 Reads

Comparison of invasive and non-invasive aortic wave intensity and wave power analyses in sheep.

Physiol Meas 2019 Jan 29;40(1):015005. Epub 2019 Jan 29.

Murdoch Children's Research Institute, University of Melbourne, Melbourne, Australia. Department of Cardiology, Royal Children's Hospital, University of Melbourne, Melbourne, Australia. Departments of Paediatrics, University of Melbourne, Melbourne, Australia.

Objective: Wave intensity (WI) and wave power (WP) analyses are powerful approaches for assessing ventricular-vascular interactions and arterial dynamics using invasive and non-invasive methods. However, in vivo comparison of these methods for large arteries is lacking. This study assessed agreement, correlation and relative changes in wave size in invasive and non-invasive aortic WI/WP analyses, and associated sources of error. Read More

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http://dx.doi.org/10.1088/1361-6579/aafcc4DOI Listing
January 2019
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Measurement error of 3D kinematic and kinetic measures during overground endurance running in recreational runners between two test sessions separated by 48 h.

Physiol Meas 2019 Feb 22;40(2):024002. Epub 2019 Feb 22.

Correspondence address: Department of Sport, Exercise and Rehabilitation, Health and Life Sciences, Northumbria University, Northumberland Building, Newcastle upon Tyne, NE1 8ST, England, United Kingdom.

Objective: The purpose of this study was to quantify the measurement error of 3D kinematic and kinetic measures during overground endurance running between two sessions separated by 48 h.

Approach: Thirteen recreational runners were assessed on two occasions while running overground, over embedded force plates and through an array of 3D cameras.

Main Results: In the sagittal, frontal and transverse planes, over the entire stance phase, the typical error of kinematic variables ranged from 1. Read More

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http://dx.doi.org/10.1088/1361-6579/aafa87DOI Listing
February 2019
5 Reads

Different strategies to initiate and maintain hyperventilation: their effect on continuous estimates of dynamic cerebral autoregulation.

Physiol Meas 2019 Jan 23;40(1):015003. Epub 2019 Jan 23.

Department of Cardiovascular Sciences, Cerebral Haemodynamics in Ageing and Stroke Medicine (CHIASM) Cardiovascular Sciences Research Group, University of Leicester, Leicester, United Kingdom. Department of Cardiovascular Sciences, University of Leicester, Leicester LE2 7LX, United Kingdom. Author to whom any correspondence should be addressed.

Objective: Capnography is a key monitoring intervention in several neurologically vulnerable clinical states. Cerebral autoregulation (CA) describes the ability of the cerebrovascular system to maintain a near constant cerebral blood flow throughout fluctuations in systemic arterial blood pressure, with the partial pressure of arterial carbon dioxide known to directly influence CA. Previous work has demonstrated dysautoregulation lasting around 30 s prior to the anticipated augmentation of hyperventilation-associated hypocapnia. Read More

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http://dx.doi.org/10.1088/1361-6579/aafab6DOI Listing
January 2019
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Continuous monitoring of cerebrovascular reactivity through pulse transit time and intracranial pressure.

Physiol Meas 2019 Jan 23;40(1):01LT01. Epub 2019 Jan 23.

Department of Physiological Nursing, University of California, San Francisco, 2 Koret Way, San Francisco, CA, 94143, United States of America. Author to whom any correspondence should be addressed.

Objective: Cerebrovascular reactivity (CR) is a mechanism that maintains stable blood flow supply to the brain. Pressure reactivity index (PRx), the correlation coefficient between slow waves of invasive arterial blood pressure (ABP) and intracranial pressure (ICP) has been validated for CR assessment. However, in clinical ward, not every subarachnoid hemorrhage (SAH) patient has invasive ABP monitoring. Read More

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http://dx.doi.org/10.1088/1361-6579/aafab1DOI Listing
January 2019
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Intestinal resection of a porcine model under thermographic monitoring.

Physiol Meas 2019 Jan 29;40(1):014003. Epub 2019 Jan 29.

Faculty of Medicine, Department of Biophysics, Masaryk University, Brno, Czech Republic.

Objective: Surgical resection of a part of the intestine is a standard procedure in gastrointestinal surgery and in order to perform this type of surgery successfully, tissue blood flow must be evaluated clearly. There exists a theoretical indication that it would be possible to use infrared thermography (IRT) for this purpose. Therefore, the main objective of the study is the qualitative evaluation of the infrared thermography method as an ancillary method for determining the resection lines and forming an optimal intestinal anastomosis on the porcine model. Read More

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http://dx.doi.org/10.1088/1361-6579/aafa8eDOI Listing
January 2019
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Monitoring respiration using the pressure sensors in a dialysis machine.

Physiol Meas 2019 Feb 8;40(2):025001. Epub 2019 Feb 8.

Department of Biomedical Engineering, Lund University, Lund, Sweden.

Objective: Although respiratory problems are common among patients with end-stage renal disease, respiration is not continuously monitored during dialysis. The purpose of the present study is to investigate the feasibility of monitoring respiration using the pressure sensors of the dialysis machine.

Approach: Respiration induces variations in the blood pressure that propagates to the extracorporeal circuit of the dialysis machine. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf978DOI Listing
February 2019
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An active learning framework for enhancing identification of non-artifactual intracranial pressure waveforms.

Physiol Meas 2019 Jan 18;40(1):015002. Epub 2019 Jan 18.

Department of Neurology, Columbia University Irving Medical Center, New York, NY, United States of America.

Objective: Intracranial pressure (ICP) is an important and established clinical measurement that is used in the management of severe acute brain injury. ICP waveforms are usually triphasic and are susceptible to artifact because of transient catheter malfunction or routine patient care. Existing methods for artifact detection include threshold-based, stability-based, or template matching, and result in higher false positives (when there is variability in the ICP waveforms) or higher false negatives (when the ICP waveforms lack complete triphasic components but are valid). Read More

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http://dx.doi.org/10.1088/1361-6579/aaf979DOI Listing
January 2019
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Fluid distribution and cell integrity indicators evaluated by bioelectrical impedance in university athletes: comparison between team sports and individual sports.

Physiol Meas 2019 Jan 23;40(1):015004. Epub 2019 Jan 23.

Federal University of Santa Catarina, Research Center in Kinanthropometry and Human Performance, Florianópolis, Brazil. Federal University of Santa Catarina, Research Center in Kinanthropometry and Human Performance, Sports Centre, University Campus, Trindade, 88040-900 Florianópolis, Santa Catarina, Brazil. Author to whom any correspondence should be addressed.

Objective: To compare indicators of fluid distribution and cellular integrity in university athletes through a cross-sectional study of 167 university athletes (18-35 years) who competed in team sports and individual sports.

Approach: Bioimpedance was used to estimate total body water (TBW), intracellular water (ICW), extracellular water (ECW), ECW/ICW ratio, impedance (Z), reactance (Xc), resistance (R), phase angle, body cell mass (BCM) and ECW/BCM ratio at a frequency of 50 kHz. X-ray absorptiometry was used to determine lean soft tissue mass and body fat. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf8cdDOI Listing
January 2019
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Photoplethysmography in dogs and cats: a selection of alternative measurement sites for a pet monitor.

Physiol Meas 2019 Jan 23;40(1):01NT02. Epub 2019 Jan 23.

Biophotonics Laboratory, Institute of Atomic Physics and Spectroscopy, University of Latvia, 19 Raina Blvd., LV-1586, Riga, Latvia.

Objective: Photoplethysmography (PPG) is an increasingly popular health and well-being tool for monitoring heart rate and oxygen saturation. Due to the pigmentation and hairiness of dogs and cats, a pulse oximeter is routinely placed solely on the tongue. As this approach is feasible only for pet monitor use during surgical procedures, we investigate PPG signal quality on several other measurement sites that would be better tolerated by conscious animals. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf433DOI Listing
January 2019
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AF detection from ECG recordings using feature selection, sparse coding, and ensemble learning.

Physiol Meas 2018 Dec 24;39(12):124007. Epub 2018 Dec 24.

Department of Electrical Engineering, University of Management and Technology, Lahore, Pakistan.

Objective: The objective of this paper is to provide an algorithm for accurate, automated detection of atrial fibrillation (AF) from ECG signals. Four types of ECG signals are considered: normal signals, signals representing symptoms of AF, other signals, and noisy signals. This paper represents follow-up work to the authors' entry in the 2017 PhysioNet Challenge as reported in the 2017 Computing in Cardiology Conference. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf35bDOI Listing
December 2018
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Coupling of local muscle deoxygenation and autonomic control depends on exercise intensity-insights from transfer entropy analysis.

Physiol Meas 2018 Dec 7;39(12):125005. Epub 2018 Dec 7.

Faculty of Physics, Warsaw University of Technology, Koszykowa 75, 00-662, Poland. Authors contributed equally to this manuscript.

Objective: We analyzed the driving component between the periods of adjacent heartbeats (R-R intervals) and vastus lateralis-deoxygenation (%HHb) during incremental cycling. Considering a tight matching of local metabolism with systemic and local perfusion, a coupling between indices of cardiovascular control (R-R variability) and %HHb is suggested. Further, an intensity-dependent coupling between R-R variability and %HHb was hypothesized, because a multitude of feedback and feedforward mechanisms to autonomic cardiovascular control as well as local vasodilating mechanisms are associated with muscle metabolism and thus exercise intensity. Read More

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http://dx.doi.org/10.1088/1361-6579/aaec9aDOI Listing
December 2018
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Feature relevance in physiological networks for classification of obstructive sleep apnea.

Physiol Meas 2018 Dec 21;39(12):124003. Epub 2018 Dec 21.

Center of Biomedical Image and Information Processing, HTW Berlin-University of Applied Sciences Berlin, Berlin, Germany. Sleep Medicine Center, Charité-Universitätsmedizin Berlin, Berlin, Germany.

Objective: Physiological networks (PN) model couplings between organs in a high-dimensional parameter space. Machine learning methods, in particular artifical neural networks (ANNs), are powerful on high-dimensional classification tasks. However, lack of interpretability of the resulting models has been a drawback in research. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf0c9DOI Listing
December 2018
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Automatic sleep stages classification using respiratory, heart rate and movement signals.

Physiol Meas 2018 Dec 24;39(12):124008. Epub 2018 Dec 24.

HTWG Konstanz, Konstanz, Germany. University of Seville, Seville, Spain.

Objective: This paper presents an algorithm for non-invasive sleep stage identification using respiratory, heart rate and movement signals. The algorithm is part of a system suitable for long-term monitoring in a home environment, which should support experts analysing sleep.

Approach: As there is a strong correlation between bio-vital signals and sleep stages, multinomial logistic regression was chosen for categorical distribution of sleep stages. Read More

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http://dx.doi.org/10.1088/1361-6579/aaf5d4DOI Listing
December 2018
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Network proteomics of human dermal wound healing.

Physiol Meas 2018 Dec 7;39(12):124002. Epub 2018 Dec 7.

Department of Computer Science, School of Engineering, Virginia Commonwealth University, Richmond, VA, United States of America.

Objective: The healing of wounds is critical in protecting the human body against environmental factors. The mechanisms involving protein expression during this complex physiological process have not been fully elucidated.

Approach: Here, we use reverse-phase protein microarrays (RPPA) involving 94 phosphoproteins to study tissue samples from tubes implanted in healing dermal wounds in seven human subjects tracked over two weeks. Read More

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http://stacks.iop.org/0967-3334/39/i=12/a=124002?key=crossre
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http://dx.doi.org/10.1088/1361-6579/aaee19DOI Listing
December 2018
13 Reads