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Sensors (Basel, Switzerland) Mar 2016Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to...
Photoplethysmographic (PPG) waveforms are used to acquire pulse rate (PR) measurements from pulsatile arterial blood volume. PPG waveforms are highly susceptible to motion artifacts (MA), limiting the implementation of PR measurements in mobile physiological monitoring devices. Previous studies have shown that multichannel photoplethysmograms can successfully acquire diverse signal information during simple, repetitive motion, leading to differences in motion tolerance across channels. In this paper, we investigate the performance of a custom-built multichannel forehead-mounted photoplethysmographic sensor under a variety of intense motion artifacts. We introduce an advanced multichannel template-matching algorithm that chooses the channel with the least motion artifact to calculate PR for each time instant. We show that for a wide variety of random motion, channels respond differently to motion artifacts, and the multichannel estimate outperforms single-channel estimates in terms of motion tolerance, signal quality, and PR errors. We have acquired 31 data sets consisting of PPG waveforms corrupted by random motion and show that the accuracy of PR measurements achieved was increased by up to 2.7 bpm when the multichannel-switching algorithm was compared to individual channels. The percentage of PR measurements with error ≤ 5 bpm during motion increased by 18.9% when the multichannel switching algorithm was compared to the mean PR from all channels. Moreover, our algorithm enables automatic selection of the best signal fidelity channel at each time point among the multichannel PPG data.
Topics: Algorithms; Heart Rate; Humans; Monitoring, Physiologic; Motion; Oximetry; Photoplethysmography; Signal Processing, Computer-Assisted
PubMed: 26959034
DOI: 10.3390/s16030342 -
Computers in Biology and Medicine Mar 2023Pulse rate (PR) is one of the most important markers for assessing a person's health. With the increasing demand for long-term health monitoring, much attention is being...
Pulse rate (PR) is one of the most important markers for assessing a person's health. With the increasing demand for long-term health monitoring, much attention is being paid to contactless PR estimation using imaging photoplethysmography (iPPG). This non-invasive technique is based on the analysis of subtle changes in skin color. Despite efforts to improve iPPG, the existing algorithms are vulnerable to less-constrained scenarios (i.e., head movements, facial expressions, and environmental conditions). In this article, we propose a novel end-to-end spatio-temporal network, namely X-iPPGNet, for instantaneous PR estimation directly from facial video recordings. Unlike most existing systems, our model learns the iPPG concept from scratch without incorporating any prior knowledge or going through the extraction of blood volume pulse signals. Inspired by the Xception network architecture, color channel decoupling is used to learn additional photoplethysmographic information and to effectively reduce the computational cost and memory requirements. Moreover, X-iPPGNet predicts the pulse rate from a short time window (2 s), which has advantages with high and sharply fluctuating pulse rates. The experimental results revealed high performance under all conditions including head motions, facial expressions, and skin tone. Our approach significantly outperforms all current state-of-the-art methods on three benchmark datasets: MMSE-HR (MAE = 4.10 ; RMSE = 5.32 ; r = 0.85), UBFC-rPPG (MAE = 4.99 ; RMSE = 6.26 ; r = 0.67), MAHNOB-HCI (MAE = 3.17 ; RMSE = 3.93 ; r = 0.88).
Topics: Humans; Heart Rate; Deep Learning; Algorithms; Skin; Video Recording; Photoplethysmography
PubMed: 36709517
DOI: 10.1016/j.compbiomed.2023.106592 -
American Journal of Respiratory and... Feb 1999Although epidemiological studies have linked particulate air pollution with cardiopulmonary mortality, underlying biological mechanisms remain largely unknown.... (Comparative Study)
Comparative Study
Although epidemiological studies have linked particulate air pollution with cardiopulmonary mortality, underlying biological mechanisms remain largely unknown. Unexplored pathophysiological pathways include transient declines in blood oxygenation and/or changes in cardiac rhythm following particulate exposure. In this study, blood oxygen saturation using pulse oximetry (SpO2) and pulse rate were measured daily on a panel of 90 elderly subjects during the winter of 1995-1996 in Utah Valley. Associations of SpO2 and pulse rate with respirable particulate pollution (particles with an aerodynamic diameter = a nominal 10 microm [PM10]) were evaluated. SpO2 was not consistently associated with PM10. Pulse rate and the odds of the pulse rate being elevated by 5 or 10 beats per minute (beats/min) were associated with PM10 on the previous 1 to 5 d. A 100 microg/m3 increase in previous-day PM10 was associated with an average increase of 0.8 beats/min and 29 and 95% increased odds of the pulse rate being elevated by 5 or 10 beats/min, respectively. Although there was little evidence of pollution-related hypoxia, alterations in pulse rate could reflect cardiac rhythm changes and may be part of the pathophysiology linking particles to cardiopulmonary mortality. The observed lag structure is consistent with particulate-induced pulmonary inflammation and cytokine release, but the biological relevance requires further study.
Topics: Aged; Air Pollutants; Female; Follow-Up Studies; Heart Diseases; Heart Rate; Humans; Inhalation Exposure; Lung Diseases; Male; Odds Ratio; Oximetry; Oxygen; Retrospective Studies; Survival Rate; Utah
PubMed: 9927345
DOI: 10.1164/ajrccm.159.2.9702103 -
American Journal of Physiology. Heart... Jul 2014Heart rate variability (HRV) is a function of cardiac autonomic tone that is widely used in both clinical and animal studies. In preclinical studies, HRV measures are...
Heart rate variability (HRV) is a function of cardiac autonomic tone that is widely used in both clinical and animal studies. In preclinical studies, HRV measures are frequently derived using the arterial pulse waveform from an implanted pressure telemetry device, termed pulse rate variability (PRV), instead of the electrocardiogram signal in accordance with clinical guidelines. The acceptability of PRV as a surrogate for HRV in instrumented animals is unknown. Using rabbits implanted with intracardiac leads and chronically implanted pressure transducers, we investigated the correlation and agreement of time-domain, frequency-domain, and nonlinear indexes of HRV and PRV at baseline. We also investigated the effects of ventricular pacing and autonomic blockade on both measures. At baseline, HRV and PRV time- and frequency-domain parameters showed robust correlations and moderate to high agreement, whereas nonlinear parameters showed slightly weaker correlations and varied agreement. Ventricular pacing almost completely eliminated HRV, and spectral analysis of the PRV signal revealed a HRV-independent rhythm. After cardiac autonomic blockade with atropine or metoprolol, the changes in time- and non-normalized frequency-domain measures of PRV continued to show strong correlations and moderate to high agreement with corresponding changes in HRV measures. Blockade-induced changes in nonlinear PRV indexes correlated poorly with HRV changes and showed weak agreement. These results suggest that time- and frequency-domain measures of PRV are acceptable surrogates for HRV even in the context of changing cardiac autonomic tone, but caution should be used when nonlinear measures are a primary end point or when HRV is very low as HRV-independent rhythms may predominate.
Topics: Animals; Arrhythmias, Cardiac; Electrocardiography; Heart Rate; Male; Pulse Wave Analysis; Rabbits; Reproducibility of Results; Sensitivity and Specificity
PubMed: 24791786
DOI: 10.1152/ajpheart.00898.2013 -
Studies in Health Technology and... Nov 2023Extracorporeal pacemaker is cardiac rhythm management device with non-implantable pulse generator and is widely used medical institutions. Parameters such as pulse...
Extracorporeal pacemaker is cardiac rhythm management device with non-implantable pulse generator and is widely used medical institutions. Parameters such as pulse duration, pulse amplitude, pulse rate, sensibility, and PVARP can directly decide the metrological performance of the instrument. However, at present, there is no relevant calibration specification for extracorporeal pacemaker in China to calibrate the important parameters. This article presents a novel calibration method for extracorporeal pacemaker by determining corresponding environmental conditions, calibration standards, and calculation equations. The calibration results of the important parameters can meet the requirements of GB 16174.2-2015 Implants for surgery - Active implantable medical devices - Part 2 Cardiac pacemakers, which shows that the calibration method is scientific and practical for metrological performance evaluation of extracorporeal pacemaker.
Topics: Calibration; Pacemaker, Artificial; Prostheses and Implants; Heart Rate; China
PubMed: 38007769
DOI: 10.3233/SHTI230869 -
Cadernos de Saude Publica Oct 2010The aim of this study was to describe resting pulse rate and associated factors among adolescents. This was a cross-sectional analysis nested in a prospective cohort...
The aim of this study was to describe resting pulse rate and associated factors among adolescents. This was a cross-sectional analysis nested in a prospective cohort study, including 4,452 adolescents born in Pelotas, Rio Grande do Sul State, Brazil in 1993, representing 87.5% of the original cohort. Pulse rate was measured with an electronic device at the beginning and end of the interview, and the mean value was used in the analyses. Mean pulse rate was 78.4 bpm (SD = 11.0) in the total sample, 76.5 bpm (SD = 10.7) in boys, and 80.2 bpm (SD = 10.9; p < 0.001) in girls. Black adolescents showed lower mean pulse rates. There was a direct association between pulse rate and blood pressure. Physical activity was inversely associated with pulse rate in the crude analysis only. Elevated pulse rate is strongly associated with high blood pressure, and both variables are predictors of risk of chronic disease in adulthood.
Topics: Blood Pressure; Brazil; Child; Cohort Studies; Cross-Sectional Studies; Female; Heart Rate; Humans; Male; Motor Activity; Rest
PubMed: 20963294
DOI: 10.1590/s0102-311x2010001000013 -
Nihon Ronen Igakkai Zasshi. Japanese... 2023Although the number of deaths in bathtubs in homes and residential facilities for the elderly has been decreasing slightly since 2017, it is still 4,900 (2019), which is...
INTRODUCTION
Although the number of deaths in bathtubs in homes and residential facilities for the elderly has been decreasing slightly since 2017, it is still 4,900 (2019), which is almost twice the number of traffic accident deaths.
PURPOSE
The purpose of this study was to investigate blood pressure and pulse fluctuations in community-dwelling elderly people during bathing, and to examine the alert range to determine when heat shock occurs.
METHODS
Ten elderly men (72.6±3.4/67-78) living in the community were subjected to a 6-minute full-body bath in a bath with a temperature of 41°C, and their blood pressure (SBP, DBP) and pulse (PR) were measured.
RESULTS
The SBP of the group whose PR increased by 15/min or more from before bathing to 30 seconds after bathing increased by about 30 mmHg. In the group where PR increased by 15/min or more, the pulse pressure (PP) increased by about 30 mmHg, and in the double product (DP), the abnormal increase of 5,000 DP or more was observed from before bathing to 30 seconds after bathing.
DISCUSSION
In the group where PR increased by 15/min or more from before bathing to 30 seconds after bathing, there is a possibility of cerebral hemorrhage immediately after bathing, dizziness, and falls. Analysis of pulse pressure (PP) and double product (DP) also suggests that the burden on the heart is applied 30 seconds after bathing, and sufficient attention is required.
Topics: Male; Humans; Aged; Blood Pressure; Heart Rate; Baths
PubMed: 38171761
DOI: 10.3143/geriatrics.60.434 -
Physiological Measurement Feb 2013This work presents the evaluation of pulse rate variability (PRV) obtained from pulse onsets of photoplethysmographic (PPG) signals. Three published algorithms were used... (Comparative Study)
Comparative Study
This work presents the evaluation of pulse rate variability (PRV) obtained from pulse onsets of photoplethysmographic (PPG) signals. Three published algorithms were used to determine the pulse onsets: diastolic point, maximum second derivative and tangent intersection. Temporal series of pulse onsets were obtained for each method, and several variability indices were derived from these series. Simultaneous ECG and PPG records were acquired from 37 healthy volunteers to evaluate the interchangeability between PRV indices and heart rate variability (HRV) indices by the Bland-Altman method. Furthermore, the concordance correlation coefficient was used to correlate the indices. In all the cases, PRV indices obtained through the tangent intersection method showed better accuracy and precision (Bland-Altman analysis, bias ± 1.96 standard deviation: low frequency, LF(ms)(2) = -28.06 ± 72.68; high frequency, HF(ms)(2) = -68.23 ± 192.85; high frequency in normalized units, HF(nu) =-2.02 ± 7.08; LF/HF = 0.17 ± 0.71) and higher correlation (concordance correlation coefficients: low frequency, LF(ms)(2) = 0.99; high frequency, HF(ms)(2) = 0.98; high frequency in normalized units, HF(nu) = 0.97; LF/HF = 0.90) with HRV indices than other methods, and could be used as a good surrogate of HRV.
Topics: Algorithms; Diagnosis, Computer-Assisted; Heart Rate; Humans; Photoplethysmography; Pulse; Reproducibility of Results; Sensitivity and Specificity
PubMed: 23348575
DOI: 10.1088/0967-3334/34/2/179 -
Psychophysiology Jan 2020Previous studies have identified reduced heart rate variability (HRV) in post-traumatic stress disorder (PTSD), which may temporally precede the onset of the disorder. A...
Previous studies have identified reduced heart rate variability (HRV) in post-traumatic stress disorder (PTSD), which may temporally precede the onset of the disorder. A separate line of functional neuroimaging research in PTSD has consistently demonstrated hypoactivation of the ventromedial prefrontal cortex (vmPFC), a key aspect of a descending neuromodulatory system that exerts inhibitory control over heart rate. No research to date, however, has simultaneously investigated whether altered vmPFC activation is associated with reduced HRV and elevated PTSD symptoms in the same individuals. Here, we collected fMRI data during alternating conditions of threat of shock and safety from shock in 51 male combat-exposed veterans with either high or low levels of PTSD symptoms. Pulse rate variability (PRV)-a HRV surrogate calculated from pulse oximetry-was assessed during a subsequent resting scan. Correlational analyses tested for hypothesized relationships between reduced vmPFC activation, lower PRV, and elevated PTSD symptomatology. We found that PTSD re-experiencing symptoms were inversely associated with high-frequency (HF)-PRV, thought to primarily reflect parasympathetic control of heart rate, in veterans with elevated PTSD symptoms. Reduced vmPFC activation for the contrast of safety-threat was associated both with lower HF-PRV and elevated PTSD re-experiencing symptoms. These results tie together previous observations of reduced HRV/PRV and impaired vmPFC function in PTSD and call for further research on reciprocal brain-body relationships in understanding PTSD pathophysiology.
Topics: Adult; Brain Mapping; Combat Disorders; Heart Rate; Humans; Magnetic Resonance Imaging; Male; Prefrontal Cortex; Stress Disorders, Post-Traumatic; Veterans; Young Adult
PubMed: 30793774
DOI: 10.1111/psyp.13352 -
Annual International Conference of the... Aug 2016Heart Rate Variability (HRV) analysis can be of precious help in most of clinical situations because it is able to quantify the Autonomic Nervous System (ANS) activity....
Heart Rate Variability (HRV) analysis can be of precious help in most of clinical situations because it is able to quantify the Autonomic Nervous System (ANS) activity. The HRV high frequency (HF) content, related to the parasympathetic tone, reflects the ANS response to an external stimulus responsible of pain, stress or various emotions. We have previously developed the Analgesia Nociception Index (ANI), based on HRV high frequency content estimation, which quantifies continuously the vagal tone in order to guide analgesic drug administration during general anesthesia. This technology has been largely validated during the peri-operative period. Currently, ANI is obtained from a specific algorithm analyzing a time series representing successive heart periods measured on the electrocardiographic (ECG) signal. In the perspective of widening the application fields of this technology, in particular for homecare monitoring, it has become necessary to simplify signal acquisition by using e.g. a pulse plethysmographic (PPG) sensor. Even if Pulse Rate Variability (PRV) analysis issued from PPG sensors has been shown to be unreliable and a bad predictor of HRV analysis results, we have compared PRV and HRV both estimated by ANI as well as HF and HF/(HF+LF) spectral analysis on both signals.
Topics: Algorithms; Analgesia; Autonomic Nervous System; Electrocardiography; Heart Rate; Humans; Plethysmography
PubMed: 28268478
DOI: 10.1109/EMBC.2016.7590855