Population-based reference values for 4D flow MRI derived aortic blood flow parameters
This study assesses age-related differences of thoracic aorta blood flow profiles and provides age- and sex-specific reference values using 4D flow cardiovascular magnetic resonance (CMR) data. Approach. 126 volunteers (age 20 –80 years, female 51%) underwent 4D flow CMR and 12 perpendicular analysis planes in the thoracic aorta were specified. For these planes the following parameters were evaluated: body surface area-adjusted aortic area (A′), normalized flow displacement (NFD), the degree of wall parallelism (WPD), the minimal relative cross-sectional area through which 80% of the volume flow passes (A80) and the an...
Source: Physiological Measurement - March 7, 2023 Category: Physiology Authors: Marie Schafstedde, Lina Jarmatz, Jan Br üning, Markus Hüllebrand, Sarah Nordmeyer, Andreas Harloff and Anja Hennemuth Source Type: research
Automated detection of schizophrenia using deep learning: a review for the last decade
Schizophrenia (SZ) is a devastating mental disorder that disrupts higher brain functions like thought, perception, etc., with a profound impact on the individual's life. Deep learning (DL) can detect SZ automatically by learning signal data characteristics hierarchically without the need for feature engineering associated with traditional machine learning. We performed a systematic review of DL models for SZ detection. Various deep models like long short-term memory, convolution neural networks, AlexNet, etc., and composite methods have been published based on electroencephalographic signals, and structural and/or function...
Source: Physiological Measurement - March 6, 2023 Category: Physiology Authors: Manish Sharma, Ruchit Kumar Patel, Akshat Garg, Ru SanTan and U Rajendra Acharya Source Type: research
Carotid Doppler ultrasound for non-invasive haemodynamic monitoring: a narrative review
Objective. Accurate haemodynamic monitoring is the cornerstone in the management of critically ill patients. It guides the optimization of tissue and organ perfusion in order to prevent multiple organ failure. In the past decades, carotid Doppler ultrasound (CDU) has been explored as a non-invasive alternative for long-established invasive haemodynamic monitoring techniques. Considering the large heterogeneity in reported studies, we conducted a review of the literature to clarify the current status of CDU as a haemodynamic monitoring tool. Approach. In this article, firstly an overview is given of the equipment and workfl...
Source: Physiological Measurement - March 1, 2023 Category: Physiology Authors: Irene Suriani, Joris van Houte, Esm ée C de Boer, Luuk van Knippenberg, Sabina Manzari, Massimo Mischi and R Arthur Bouwman Source Type: research
Screening left ventricular systolic dysfunction in children using intrinsic frequencies of carotid pressure waveforms measured by a novel smartphone-based device
Objective. Children with heart failure have higher rates of emergency department utilization, health care expenditure, and hospitalization. Therefore, a need exists for a simple, non-invasive, and inexpensive method of screening for left ventricular (LV) dysfunction. We recently demonstrated the practicality and reliability of a wireless smartphone-based handheld device in capturing carotid pressure waveforms and deriving cardiovascular intrinsic frequencies (IFs) in children with normal LV function. Our goal in this study was to demonstrate that an IF-based machine learning method (IF-ML) applied to noninvasive carotid pr...
Source: Physiological Measurement - March 1, 2023 Category: Physiology Authors: Andrew L Cheng, Jing Liu, Stephen Bravo, Jennifer C Miller and Niema M Pahlevan Source Type: research
Extraction of cardiac-related signals from a suprasternal pressure sensor during sleep
Objective. The accurate detection of respiratory effort during polysomnography is a critical element in the diagnosis of sleep-disordered breathing conditions such as sleep apnea. Unfortunately, the sensors currently used to estimate respiratory effort are either indirect and ignore upper airway dynamics or are too obtrusive for patients. One promising alternative is the suprasternal notch pressure (SSP) sensor: a small element placed on the skin in the notch above the sternum within an airtight capsule that detects pressure swings in the trachea. Besides providing information on respiratory effort, the sensor is sensitive...
Source: Physiological Measurement - March 1, 2023 Category: Physiology Authors: Luca Cerina, Gabriele B Papini, Pedro Fonseca, Sebastiaan Overeem, Johannes P van Dijk and Rik Vullings Source Type: research
Characterization of rheumatic heart disease from electrocardiogram recordings
This study addressed the possible use of ECG recordings for the characterization of problems of the heart in RHD patients. Approach. To this end, an extensive ECG dataset was collected from patients suffering from RHD (PwRHD), and healthy control subjects (HC). Bandpass filtering was used at the preprocessing stage. Each data was then standardized by removing its mean and dividing by its standard deviation. Delineation of the onsets and offsets of waves was performed using KIT-IBT open ECG MATLAB toolbox. PR interval, QRS duration, RR intervals, QT intervals, and QTc intervals were computed for each heartbeat. The median v...
Source: Physiological Measurement - March 1, 2023 Category: Physiology Authors: Melkamu Hunegnaw Asmare, Amsalu Tomas Chuma, Carolina Varon, Frehiwot Woldehanna, Luc Janssens and Bart Vanrumste Source Type: research
Cardio-respiratory interactions in response to lower-body negative pressure
The relationship between heart rate and blood pressure, as well as cardiorespiratory coupling, play a critical role in maintaining blood pressure and organ perfusion during conditions of blood loss. Traditional vital signs such as blood pressure, breathing rate, and oxygen saturation are poor markers of blood loss, making it difficult for medics to assess the severity of central hypovolemia. Monitoring hemorrhage is further complicated by the fact that some patients have a low tolerance to hemorrhage and would reach the point of cardiovascular collapse in less time than high tolerant individuals. Therefore, this study aime...
Source: Physiological Measurement - February 28, 2023 Category: Physiology Authors: Rabie Fadil, Ajay K Verma, Farshid Sadeghian, Andrew P Blaber and Kouhyar Tavakolian Source Type: research
Regional variations distinguish auditory from visual evoked potentials in healthy 4 week old piglets
Objective. Evoked potentials (EP), measured using electroencephalographic (EEG) recordings provide an opportunity to monitor cognitive dysfunctions after neurological diseases or traumatic brain injury (TBI). The 4 week old piglet is an established model of paediatric TBI; therefore, healthy piglets were studied to establish feasibility of obtaining responses to auditory and visual stimuli. A secondary aim was to input the EEG data into a piglet computational model to localize the brain sources related to processing. We tested the hypotheses: (1) visual, auditory-standard, and auditory-target stimuli elicit responses, (2) ...
Source: Physiological Measurement - February 28, 2023 Category: Physiology Authors: R Anna Oeur, Maduran Palaniswamy, Matthew Ha, Mariano Fernandez-Corazza and Susan S Margulies Source Type: research
Postural and longitudinal variability in seismocardiographic signals
This study aims to quantify postural and longitudinal SCG variability in healthy resting subjects during normal breathing. Approach. SCG and ECG signals were longitudinally acquired in 19 healthy subjects at different postures (supine, 45 ° head up, and sitting) during five recording sessions over five months. SCG cycles were segmented using the ECG R wave. Unsupervised machine learning was used to reduce SCG variability due to respiration by grouping the SCG signals into two clusters with minimized intra-cluster waveform heterogene ity. Several SCG features were assessed at different postures and longitudinally. Main res...
Source: Physiological Measurement - February 27, 2023 Category: Physiology Authors: Md Khurshidul Azad, Peshala T Gamage, Rajkumar Dhar, Richard H Sandler and Hansen A Mansy Source Type: research
Improved Parkinsonian tremor quantification based on automatic label modification and SVM with RBF kernel
In this study, an automatic modification method for the labels judged by clinicians is pre sented to improve Parkinsonian tremor quantitation. Approach. For the severe overlapping of dynamic feature range between different severities, an outlier modification algorithm (PCA-IQR) based on the combination of principal component analysis and interquartile range statistic rule is proposed to l earn the blurred borders between different severity scores, thereby optimizing the labels. Afterward, according to the modified feature vectors, a support vector machine (SVM) with a radial basis function (RBF) kernel is proposed to class...
Source: Physiological Measurement - February 20, 2023 Category: Physiology Authors: Yumin Li, Zengwei Wang and Houde Dai Source Type: research
Interactive slide selection algorithm and machine learning in psychophysiological memory testing
Objective. To present a new type of concealed information test (CIT) that implements the interactive slide selection (ISS) algorithm and compare its effectiveness with a standard CIT (sCIT). Approach. The ISS algorithm presents slides interactively, based on the analysis of electrodermal activity, while sCIT presents slides in a predefined, sequential order. The algorithm automatically selects irrelevant, relevant, and control slides and presents them at the moment which is physiologically most suitable for electrodermal response detection. To compare the ISS-based CIT (issCIT) and sCIT, two objects, a bag, and a wallet, w...
Source: Physiological Measurement - February 20, 2023 Category: Physiology Authors: Vladimir Randjelovic Source Type: research
3D ECG display with deep learning approach for identification of cardiac abnormalities from a variable number of leads
The objective of this study is to explore new imaging techniques with the use of the deep learning method for the identification of cardiac abnormalities present in electrocardiogram (ECG) signals with 2, 3, 4, 6 and 12-lead in the framework of the PhysioNet/Computing in Cardiology Challenge 2021. The training set is a public database of 88,253 twelve-lead ECG recordings lasting from 6 s to 60 s. Each ECG recording has one or more diagnostic labels. The six-lead, four-lead, three-lead, and two-lead are reduced-lead versions of the original twelve-lead data. Approach. The deep learning method considers images that are built...
Source: Physiological Measurement - February 16, 2023 Category: Physiology Authors: Giovanni Bortolan Source Type: research
Building an automated, machine learning-enabled platform for predicting post-operative complications
Objective. In 2019, the University of Florida College of Medicine launched the MySurgeryRisk algorithm to predict eight major post-operative complications using automatically extracted data from the electronic health record. Approach. This project was developed in parallel with our Intelligent Critical Care Center and represents a culmination of efforts to build an efficient and accurate model for data processing and predictive analytics. Main Results and Significance. This paper discusses how our model was constructed and improved upon. We highlight the consolidation of the database, processing of fixed and time-series ph...
Source: Physiological Measurement - February 9, 2023 Category: Physiology Authors: Jeremy A Balch, Matthew M Rupert, Benjamin Shickel, Tezcan Ozrazgat-Baslanti, Patrick J Tighe, Philip A Efron, Gilbert R Upchurch, Parisa Rashidi, Azra Bihorac and Tyler J Loftus Source Type: research
Radial artery pulse wave velocity: a new characterization technique and the instabilities associated with the respiratory phase and breath-holding
Objective. Pulse wave velocity (PWV) is a key diagnostic parameter of the cardiovascular system ’s state. However, approaches aimed at PWV characterization often suffer from inevitable drawbacks. Statistical results demonstrating how closely PWV in the radial artery (RA) and the respiration phase correlate, as well as RA PWV evolution during breath-holding (BH), have not yet been presented i n the literature. The aims of this study are (a) to propose a simple robust technique for measuring RA PWV, (b) to reveal the phase relation between the RA PWV and spontaneous breathing, and (c) to disclose the influence of BH on the...
Source: Physiological Measurement - February 6, 2023 Category: Physiology Authors: Boris G Vainer Source Type: research
A novel deep domain adaptation method for automated detection of sleep apnea/hypopnea events
Objective. Sleep apnea –hypopnea syndrome (SAHS) is a common sleep-related respiratory disorder that is generally assessed for severity using polysomnography (PSG); however, the diversity of sampling devices and patients makes this not only costly but may also degrade the performance of the algorithms. Approach. This pa per proposes a novel deep domain adaptation module which uses a long short-term memory–convolutional neural network embedded with the channel attention mechanism to achieve autonomous extraction of high-quality features. Meanwhile, a domain adaptation module was built to achieve domain-invariant f eatur...
Source: Physiological Measurement - February 6, 2023 Category: Physiology Authors: Zonglin Du, Jiao Wang, Yingxin Ren and Yingtong Ren Source Type: research
