Wearable pulmonary monitoring system with integrated functional lung imaging and chest sound recording: a clinical investigation in healthy subjects
Objective. Current wearable respiratory monitoring devices provide a basic assessment of the breathing pattern of the examined subjects. More complex monitoring is needed for healthcare applications in patients with lung diseases. A multi-sensor vest allowing continuous lung imaging by electrical impedance tomography (EIT) and auscultation at six chest locations was developed for such advanced application. The aims of our study were to determine the vest's capacity to record the intended bio-signals, its safety and the comfort of wearing in a first clinical investigation in healthy adult subjects. Approach. Twenty subjects...
Source: Physiological Measurement - April 17, 2023 Category: Physiology Authors: I Frerichs, R Paradiso, V Kilintzis, B M Rocha, F Braun, M Rapin, L Caldani, N Beredimas, R Trechlis, S Suursalu, C Strodthoff, D Pessoa, O Ch ételat, R P Paiva, P de Carvalho, N Maglaveras, N Weiler and J Wacker Source Type: research
Integrating multimodal information in machine learning for classifying acute myocardial infarction
Objective. Prompt identification and recognization of myocardial ischemia/infarction (MI) is the most important goal in the management of acute coronary syndrome. The 12-lead electrocardiogram (ECG) is widely used as the initial screening tool for patients with chest pain but its diagnostic accuracy remains limited. There is early evidence that machine learning (ML) algorithms applied to ECG waveforms can improve performance. Most studies are designed to classify MI from healthy controls and thus are limited due to the lack of consideration of ECG abnormalities from other cardiac conditions, leading to false positives. Mor...
Source: Physiological Measurement - April 17, 2023 Category: Physiology Authors: Ran Xiao, Cheng Ding, Xiao Hu, Gari D Clifford, David W Wright, Amit J Shah, Salah Al-Zaiti and Jessica K Z ègre-Hemsey Source Type: research
Reduced-order modeling and analysis of dynamic cerebral autoregulation via diffusion maps
Objective. A data-driven technique for parsimonious modeling and analysis of dynamic cerebral autoregulation (DCA) is developed based on the concept of diffusion maps. Specifically, first, a state-space description of DCA dynamics is considered based on arterial blood pressure, cerebral blood flow velocity, and their time derivatives. Next, an eigenvalue analysis of the Markov matrix of a random walk on a graph over the dataset domain yields a low-dimensional representation of the intrinsic dynamics. Further dimension reduction is made possible by accounting only for the two most significant eigenvalues. The value of their...
Source: Physiological Measurement - April 11, 2023 Category: Physiology Authors: K R M dos Santos, M I Katsidoniotaki, E C Miller, N H Petersen, R S Marshall and I A Kougioumtzoglou Source Type: research
Photoplethysmography wave morphology in patients with atrial fibrillation
This study aimed to compare morphological features of the PPG curve in patients with AF to those presenting a normal sinus rhythm (NSR) and evaluate their usefulness in AF detection. Approach. 10 min PPG signals were obtained from patients with persistent/paroxysmal AF and NSR. Nine morphological parameters (1/ ΔT), Pulse Width [PW], augmentation index [AI], b/a, e/a, [b-e]/a, crest time [CT], inflection point area [IPA], Area and five HRV parameters (heart rate [HR], Shannon entropy [ShE], root mean square of the successive differences [RMSSD], number of pairs of consecutive systolic peaks [R–R] that d iffer by more th...
Source: Physiological Measurement - April 11, 2023 Category: Physiology Authors: Miko łaj Basza, Damian Waląg, Weronika Kowalczyk, Aleksandra Bożym, Michalina Ciurla, Małgorzata Krzyżanowska, Cezary Maciejewski, Wojciech Bojanowicz, Mateusz Soliński and Łukasz Kołtowski Source Type: research
Impacts of respiratory fluctuations on cerebral circulation: a machine-learning-integrated 0 –1D multiscale hemodynamic model
This study aims to accurately identify the effects of respiration on the hemodynamics of the human cardiovascular system, especially the cerebral circulation. Approach: we have developed a machine learning (ML)-integrated zero –one-dimensional (0–1D) multiscale hemodynamic model combining a lumped-parameter 0D model for the peripheral vascular bed and a one-dimensional (1D) hemodynamic model for the vascular network. In vivo measurement data of 21 patients were retrieved and partitioned into 8000 data samples in which respiratory fluctuation (RF) of intrathoracic pressure (ITP) was fitted by the Fourier series. ML-base...
Source: Physiological Measurement - April 2, 2023 Category: Physiology Authors: Ruichen Li, Koichi Sughimoto, Xiancheng Zhang, Sirui Wang and Hao Liu Source Type: research
The effect of body position change on noninvasively acquired intracranial pulse waves
Objective. Craniospinal compliance (CC) is an important metric for the characterization of space-occupying neurological pathologies. CC is obtained using invasive procedures that carry risks for the patients. Therefore, noninvasive methods for acquiring surrogates of CC have been proposed, most recently based on changes in the head's dielectric properties during the cardiac cycle. Here, we have tested whether changes in body position, which are known to influence CC, are reflected in a capacitively acquired signal (hereinafter referred to as W) originating from dynamic changes of the head's dielectric properties. Approach....
Source: Physiological Measurement - April 2, 2023 Category: Physiology Authors: Andrea Boraschi, Andreas Spiegelberg, Fariba Karimi, Kevin Graf, Arya Fallahi, Esra Neufeld, Niels Kuster and Vartan Kurtcuoglu Source Type: research
Retraction: Measuring blood pressure from Korotkoff sounds as the brachial cuff inflates on average provides higher values than when the cuff deflates
(Source: Physiological Measurement)
Source: Physiological Measurement - March 24, 2023 Category: Physiology Source Type: research
Real-time imaging of traumatic brain injury using magnetic induction tomography
Objective. Early diagnosis of traumatic brain injury (TBI) is crucial for its prognosis; however, traditional computed tomography diagnostic methods rely on large medical devices with an associated lag time to receive results. Therefore, an imaging modality is needed that provides real-time monitoring, can easily be carried out to assess the extent of TBI damage, and thus guides treatment. Approach. In the present study, an improved magnetic induction tomography (MIT) data acquisition system was used to monitor TBI in an animal model and distinguish the injury level. A pneumatically controlled cortical impactor was used to...
Source: Physiological Measurement - March 21, 2023 Category: Physiology Authors: Yang Jiao, Tao Zhang, Chao Fan, Haiyan Cao, Min Chao, Liying Han, Weirui Zhang, Lei Mao, Ruigang Liu, Canhua Xu and Liang Wang Source Type: research
Monopolar and bipolar electrooculography signal characteristics due to target displacements —have we seen the whole picture?
The development of electrooculography (EOG)-based human-computer interface systems is generally based on the processing of the commonly referred to horizontal and vertical bipolar EOG channels, which are computed from a horizontally-aligned and another vertically-aligned pair of electrodes, respectively. Horizontal (vertical) target displacements are assumed to result in changes in the horizontal (vertical) EOG channel only, and any cross-talk between the bipolar channels is often neglected or incorrectly attributed solely to electrode misalignment with respect to the ocular rotation axes. Objective. The aim of this work i...
Source: Physiological Measurement - March 20, 2023 Category: Physiology Authors: Nathaniel Barbara, Tracey A Camilleri and Kenneth P Camilleri Source Type: research
Continuous blood pressure monitoring by photoplethysmography - signal preprocessing requirements based on blood flow modelling
Objective. The aim of the study is to investigate the effect of the signal sampling frequency and low-pass filtering on the accuracy of the localisation of the fiducial points of the photoplethysmographic signal (PPG), and thus on the estimation of the blood pressure (i.e. the accuracy of the estimation). Approach. Statistical analysis was performed on 3,799 data samples taken from a publicly available database. Four PPG fiducial points of each sample signal were examined in the study. Main results. Simulation suggests that for noise-free data, cubic spline interpolation causes the sampling frequency (in the considered ran...
Source: Physiological Measurement - March 17, 2023 Category: Physiology Authors: Artur Poli ński Source Type: research
CCPNet136: automated detection of schizophrenia using carbon chain pattern and iterative TQWT technique with EEG signals
Objective. Schizophrenia (SZ) is a severe, chronic psychiatric-cognitive disorder. The primary objective of this work is to present a handcrafted model using state-of-the-art technique to detect SZ accurately with EEG signals. Approach. In our proposed work, the features are generated using a histogram-based generator and an iterative decomposition model. The graph-based molecular structure of the carbon chain is employed to generate low-level features. Hence, the developed feature generation model is called the carbon chain pattern (CCP). An iterative tunable q-factor wavelet transform (ITQWT) technique is implemented in ...
Source: Physiological Measurement - March 14, 2023 Category: Physiology Authors: Mehmet Baygin, Prabal Datta Barua, Subrata Chakraborty, Ilknur Tuncer, Sengul Dogan, Elizabeth Palmer, Turker Tuncer, Aditya P Kamath, Edward J Ciaccio and U Rajendra Acharya Source Type: research
Quantitative signal quality assessment for large-scale continuous scalp electroencephalography from a big data perspective
In this study, combined from a big data perspective, we therefore describe a quantitative signal quality assessment pipeline, a stable and general threshold-based QA pipeline that automatically integrates artifact detection and new QA measures to assess continuous resting-state raw EEG data. One simulation dataset and two resting-state EEG datasets from 42 healthy subjects and 983 clinical patients were utilized to calibrate the QA pipeline. Main Results. The results demonstrate that (1) the QA indices selected are sensitive: they almost strictly and linearly decrease as the noise level increases; (2) stable, replicable QA...
Source: Physiological Measurement - March 14, 2023 Category: Physiology Authors: Lingling Zhao, Yufan Zhang, Xue Yu, Hanxi Wu, Lei Wang, Fali Li, Mingjun Duan, Yongxiu Lai, Tiejun Liu, Li Dong and Dezhong Yao Source Type: research
A novel algorithm to assess the quality of 12-lead ECG recordings: validation in a real telecardiology application
Objective. Automatic detection of Electrocardiograms (ECG) quality is fundamental to minimize costs and risks related to delayed diagnosis due to low ECG quality. Most algorithms to assess ECG quality include non-intuitive parameters. Also, they were developed using data non-representative of a real-world scenario, in terms of pathological ECGs and overrepresentation of low-quality ECG. Therefore, we introduce an algorithm to assess 12-lead ECG quality, Noise Automatic Classification Algorithm (NACA) developed in Telehealth Network of Minas Gerais (TNMG). Approach. NACA estimates a signal-to-noise ratio (SNR) for each ECG ...
Source: Physiological Measurement - March 10, 2023 Category: Physiology Authors: Jermana L de Moraes, Gabriela M M Paix ão, Paulo R Gomes, Eduardo M A M Mendes, Antônio Luiz P Ribeiro and Alessandro Beda Source Type: research
Heart rate characteristic based modelling of atrial fibrillatory rate using implanted cardiac monitor data
The objective of the present study is to investigate the feasibility of using heart rate characteristics to estimate atrial fibrillatory rate (AFR) in a cohort of atrial fibrillation (AF) patients continuously monitored with an implantable cardiac monitor. We will use a mixed model approach to investigate population effect and patient specific effects of heart rate characteristics on AFR, and will correct for the effect of previous ablations, episode duration, and onset date and time. Approach. The f-wave signals, from which AFR is estimated, were extracted using a QRST cancellation process of the AF episodes in a cohort o...
Source: Physiological Measurement - March 10, 2023 Category: Physiology Authors: Javier Saiz-Vivo, Mostafa Abdollahpur, Luca T Mainardi, Valentina D A Corino, Mirko De Melis, Robert Hatala and Frida Sandberg Source Type: research
Characterization of autonomic states by complex sympathetic and parasympathetic dynamics*
Assessment of heartbeat dynamics provides a promising framework for non-invasive monitoring of cardiovascular and autonomic states. Nevertheless, the non-specificity of such measurements among clinical populations and healthy conditions associated with different autonomic states severely limits their applicability and exploitation in naturalistic conditions. This limitation arises especially when pathological or postural change-related sympathetic hyperactivity is compared to autonomic changes across age and experimental conditions. In this frame, we investigate the intrinsic irregularity and complexity of cardiac sympathe...
Source: Physiological Measurement - March 8, 2023 Category: Physiology Authors: Mimma Nardelli, Luca Citi, Riccardo Barbieri and Gaetano Valenza Source Type: research
