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Sensors (Basel, Switzerland) Dec 2021Camera-based remote photoplethysmography (rPPG) is a low-cost and casual non-contact heart rate measurement method suitable for telemedicine. Several factors affect the...
Camera-based remote photoplethysmography (rPPG) is a low-cost and casual non-contact heart rate measurement method suitable for telemedicine. Several factors affect the accuracy of measuring the heart rate and heart rate variability (HRV) using rPPG despite HRV being an important indicator for healthcare monitoring. This study aimed to investigate the appropriate setup for precise HRV measurements using rPPG while considering the effects of possible factors including illumination, direction of the light, frame rate of the camera, and body motion. In the lighting conditions experiment, the smallest mean absolute R-R interval (RRI) error was obtained when light greater than 500 lux was cast from the front (among the following conditions-illuminance: 100, 300, 500, and 700 lux; directions: front, top, and front and top). In addition, the RRI and HRV were measured with sufficient accuracy at frame rates above 30 fps. The accuracy of the HRV measurement was greatly reduced when the body motion was not constrained; thus, it is necessary to limit the body motion, especially the head motion, in an actual telemedicine situation. The results of this study can act as guidelines for setting up the shooting environment and camera settings for rPPG use in telemedicine.
Topics: Algorithms; Heart Rate; Motion; Photoplethysmography; Telemedicine
PubMed: 34960451
DOI: 10.3390/s21248357 -
ELife Jul 2020Cardiovascular regulation is integral to life. Animal studies have identified both neural and endocrine pathways, by which the central nervous system adjusts cardiac...
Cardiovascular regulation is integral to life. Animal studies have identified both neural and endocrine pathways, by which the central nervous system adjusts cardiac output and peripheral vascular resistance to changing physiological demands. The outflow of these pathways is coordinated by various central nervous regions based on afferent information from baroreceptors, chemoreceptors, nociceptors, and circulating hormones, and is modulated by physiologic and behavioural state. In humans, however, knowledge on central cardiovascular regulation below the cortical level is scarce. Here, we show using functional MRI (fMRI) that at least three hypothalamic subsystems are involved in cardiovascular regulation in humans. The rhythmic behaviour of these systems corresponds to high and low frequency oscillations typically seen in blood pressure and heart rate variability.
Topics: Adult; Aged; Aged, 80 and over; Blood Pressure; Cardiovascular Physiological Phenomena; Central Nervous System; Female; Heart Rate; Humans; Male; Middle Aged; Monitoring, Physiologic
PubMed: 32720895
DOI: 10.7554/eLife.55316 -
European Journal of Preventive... Aug 2016Pulse palpation has been recommended as the first step of screening to detect atrial fibrillation. We aimed to determine and compare the accuracy of different methods... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Pulse palpation has been recommended as the first step of screening to detect atrial fibrillation. We aimed to determine and compare the accuracy of different methods for detecting pulse irregularities caused by atrial fibrillation.
METHODS
We systematically searched MEDLINE, EMBASE, CINAHL and LILACS until 16 March 2015. Two reviewers identified eligible studies, extracted data and appraised quality using the QUADAS-2 instrument. Meta-analysis, using the bivariate hierarchical random effects method, determined average operating points for sensitivities, specificities, positive and negative likelihood ratios (PLR, NLR); we constructed summary receiver operating characteristic plots.
RESULTS
Twenty-one studies investigated 39 interventions (n = 15,129 pulse assessments) for detecting atrial fibrillation. Compared to 12-lead electrocardiography (ECG) diagnosed atrial fibrillation, blood pressure monitors (BPMs; seven interventions) and non-12-lead ECGs (20 interventions) had the greatest accuracy for detecting pulse irregularities attributable to atrial fibrillation (BPM: sensitivity 0.98 (95% confidence interval (CI) 0.92-1.00), specificity 0.92 (95% CI 0.88-0.95), PLR 12.1 (95% CI 8.2-17.8) and NLR 0.02 (95% CI 0.00-0.09); non-12-lead ECG: sensitivity 0.91 (95% CI 0.86-0.94), specificity 0.95 (95% CI 0.92-0.97), PLR 20.1 (95% CI 12-33.7), NLR 0.09 (95% CI 0.06-0.14)). There were similar findings for smartphone applications (six interventions) although these studies were small in size. The sensitivity and specificity of pulse palpation (six interventions) were 0.92 (95% CI 0.85-0.96) and 0.82 (95% CI 0.76-0.88), respectively (PLR 5.2 (95% CI 3.8-7.2), NLR 0.1 (95% CI 0.05-0.18)).
CONCLUSIONS
BPMs and non-12-lead ECG were most accurate for detecting pulse irregularities caused by atrial fibrillation; other technologies may therefore be pragmatic alternatives to pulse palpation for the first step of atrial fibrillation screening.
Topics: Atrial Fibrillation; Electrocardiography; Heart Rate; Humans; Palpation; ROC Curve
PubMed: 26464292
DOI: 10.1177/2047487315611347 -
Revista Da Escola de Enfermagem Da U S P Sep 2019To evaluate cardiorespiratory alterations due to a single session of hyperbaric oxygen therapy. (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To evaluate cardiorespiratory alterations due to a single session of hyperbaric oxygen therapy.
METHOD
Randomized study with patients: a control group and hyperbaric oxygen therapy. Evaluations occurred in the beginning, during, and after exposure to pure oxygen above atmosphere for 2 hours. Systemic blood pressure, peripheral oxygen saturation, pulse rate, lung volume and lung capacity, and maximal inspiratory and expiratory pressures were evaluated. Peripheral oxygen saturation, pulse rate, and systemic blood pressure were evaluated during the pressurizing in the first hour. Data were evaluated by means of ANOVA, Mann-Whitney, and independent t-test (p<0.05).
RESULTS
A total of 14 adult patients were evaluated. In the group under therapy (seven subjects), aged: 49.57±14.59 years, there was a decrease in the pulse rate of 16 beats per minute after 35 minutes of therapy (intragroup analysis), and the peripheral oxygen saturation was higher within the same period compared to the control group.
CONCLUSION
The hyperbaric oxygen therapy promotes cardiorespiratory alterations with the increase of the peripheral oxygen saturation and decrease of the pulse rate, without altering blood pressure levels and the strength, volumes, and respiratory capacities.
Topics: Adult; Aged; Blood Pressure; Female; Heart Rate; Humans; Hyperbaric Oxygenation; Male; Middle Aged; Oxygen
PubMed: 31508730
DOI: 10.1590/S1980-220X2017051503469 -
Sensors (Basel, Switzerland) Aug 2019Heart rate measurement has become one of the most widely used methods of monitoring the intensity of physical activity. The purpose of this study was to assess whether...
Heart rate measurement has become one of the most widely used methods of monitoring the intensity of physical activity. The purpose of this study was to assess whether in-ear photoplethysmographic (PPG) pulse rate (PR) measurement devices represent a valid alternative to heart rate derived from electrocardiography (ECG), which is considered a gold standard. Twenty subjects (6 women, 14 men) completed one trial of graded cycling under laboratory conditions. In the trial, PR was recorded by two commercially available in-ear devices, the Dash Pro and the Cosinuss°One. They were compared to HR measured by a Bodyguard2 ECG. Validity of the in-ear PR measurement devices was tested by ANOVA, mean absolute percentage errors (MAPE), intra-class correlation coefficient (ICC), and Bland-Altman plots. Both devices achieved a MAPE ≤5%. Despite excellent to good levels of agreement, Bland-Altman plots showed that both in-ear devices tend to slightly underestimate the ECG's HR values. It may be concluded that in-ear PPG PR measurement is a promising technique that shows accurate but imprecise results under controlled conditions. However, PPG PR measurement in the ear is sensitive to motion artefacts. Thus, accuracy and precision of the measured PR depend highly on measurement site, stress situation, and exercise.
Topics: Adult; Ear; Electrocardiography; Exercise; Female; Heart Rate; Humans; Male; Middle Aged; Photoplethysmography
PubMed: 31438600
DOI: 10.3390/s19173641 -
The Journal of International Medical... Apr 2018Objectives To evaluate home blood pressure (HBP) measurements during pregnancy and postpartum and investigate differences between singleton and twin pregnancies. Methods...
Objectives To evaluate home blood pressure (HBP) measurements during pregnancy and postpartum and investigate differences between singleton and twin pregnancies. Methods This prospective study involved normotensive, pregnant women who were planning to give birth at Saitama Medical Centre, Saitama, Japan between September 2013 and March 2017. HBP and pulse rate were measured twice daily and clinical blood pressure values were determined from patient records. Results HBP values were available from 101 participants; 69 women with singleton and 32 women with twin pregnancies. Systolic BP was statistically significantly higher in twin pregnancies from 23 weeks of gestation until 8 weeks after delivery compared with singleton pregnancies. Pulse rate was also statistically significantly higher between 11 and 30 weeks gestation in women with twin pregnancies compared with those with singleton pregnancies. Conclusions BP monitoring is important in the management of twin pregnancies, especially during the later gestational weeks and postpartum period and HBP would facilitate this monitoring.
Topics: Adult; Blood Pressure; Demography; Female; Heart Rate; Humans; Pregnancy; Pregnancy, Twin
PubMed: 29350079
DOI: 10.1177/0300060517727683 -
Journal of Clinical Monitoring and... Aug 2021Calculation of peripheral capillary oxygen saturation [Formula: see text] levels in humans is often made with a pulse oximeter, using photoplethysmography (PPG)...
Calculation of peripheral capillary oxygen saturation [Formula: see text] levels in humans is often made with a pulse oximeter, using photoplethysmography (PPG) waveforms. However, measurements of PPG waveforms are susceptible to motion noise due to subject and sensor movements. In this study, we compare two [Formula: see text]-level calculation techniques, and measure the effect of pre-filtering by a heart-rate tuned comb peak filter on their performance. These techniques are: (1) "Red over Infrared," calculating the ratios of AC and DC components of the red and infrared PPG signals,[Formula: see text], followed by the use of a calibration curve to determine the [Formula: see text] level Webster (in: Design of pulse oximeters, CRC Press, Boca Raton, 1997); and (2) a motion-resistant algorithm which uses the Discrete Saturation Transform (DST) (Goldman in J Clin Monit Comput 16:475-83, 2000). The DST algorithm isolates individual "saturation components" in the optical pathway, which allows separation of components corresponding to the [Formula: see text] level from components corresponding to noise and interference, including motion artifacts. The comparison we provide here (employing the two techniques with and without pre-filtering) addresses two aspects: (1) accuracy of the [Formula: see text] calculations; and (2) computational complexity. We used both synthetic data and experimental data collected from human subjects. The human subjects were tested at rest and while exercising; while exercising, their measurements were subject to the impacts of motion. Our main conclusion is that if an uninterrupted high-quality heart rate measurement is available, then the "Red over Infrared" approach preceded by a heart-rate tuned comb filter provides the preferred trade-off between [Formula: see text]-level accuracy and computational complexity. A modest improvement in [Formula: see text] estimate accuracy at very low SNR environments may be achieved by switching to the pre-filtered DST-based algorithm (up to 6% improvement in [Formula: see text] level accuracy at -10 dB over unfiltered DST algorithm and the filtered "Red over Infrared" approach). However, this improvement comes at a significant computational cost.
Topics: Algorithms; Artifacts; Heart Rate; Humans; Oximetry; Photoplethysmography; Signal Processing, Computer-Assisted
PubMed: 32556842
DOI: 10.1007/s10877-020-00539-2 -
Pediatric Research Jul 2021Continuous heart rate (HR) and oxygenation (SpO) metrics can be useful for predicting adverse events in very low birth weight (VLBW) infants. To optimize the utility of...
BACKGROUND
Continuous heart rate (HR) and oxygenation (SpO) metrics can be useful for predicting adverse events in very low birth weight (VLBW) infants. To optimize the utility of these tools, inter-site variability must be taken into account.
METHODS
For VLBW infants at three neonatal intensive care units (NICUs), we analyzed the mean, standard deviation, skewness, kurtosis, and cross-correlation of electrocardiogram HR, pulse oximeter pulse rate, and SpO. The number and durations of bradycardia and desaturation events were also measured. Twenty-two metrics were calculated hourly, and mean daily values were compared between sites.
RESULTS
We analyzed data from 1168 VLBW infants from birth through day 42 (35,238 infant-days). HR and SpO metrics were similar at the three NICUs, with mean HR rising by ~10 beats/min over the first 2 weeks and mean SpO remaining stable ~94% over time. The number of bradycardia events was higher at one site, and the duration of desaturations was longer at another site.
CONCLUSIONS
Mean HR and SpO were generally similar among VLBW infants at three NICUs from birth through 6 weeks of age, but bradycardia and desaturation events differed in the first 2 weeks after birth. This highlights the importance of developing predictive analytics tools at multiple sites.
IMPACT
HR and SpO analytics can be useful for predicting adverse events in VLBW infants in the NICU, but inter-site differences must be taken into account in developing predictive algorithms. Although mean HR and SpO patterns were similar in VLBW infants at three NICUs, inter-site differences in the number of bradycardia events and duration of desaturation events were found. Inter-site differences in bradycardia and desaturation events among VLBW infants should be considered in the development of predictive algorithms.
Topics: Algorithms; Female; Heart Rate; Humans; Infant, Newborn; Infant, Very Low Birth Weight; Intensive Care Units, Neonatal; Male; Oximetry; Vital Signs
PubMed: 33767372
DOI: 10.1038/s41390-021-01428-3 -
Respiratory Medicine 2023Pulse rate variability (PRV) predicts stroke in patients with sleep disordered breathing (SDB). However, the relationship between PRV and cardiovascular disease (CVD)...
OBJECTIVES
Pulse rate variability (PRV) predicts stroke in patients with sleep disordered breathing (SDB). However, the relationship between PRV and cardiovascular disease (CVD) was unknown in SDB.
METHODS
This was a cross-sectional study. Community residents in Guangdong were investigated. Sleep study were conducted with a type Ⅳ sleep monitoring. PRV parameters was assessed from the pulse waveforms derived from the sleep monitoring.
RESULTS
3747 participants were enrolled. The mean age was 53.9 ± 12.7 years. 1149 (30.7%) were diagnosed as SDB. PRV parameters, except for the averages of pulse-to-pulse intervals (ANN), were higher in participants with SDB than those without. After adjusting for traditional CVD risk factors, deceleration capacity of rate (DC), ANN, and the percentage of pulse-to-pulse interval differences that were more than 50 ms (PNN50) were correlated with CVD risk in participants with SDB (OR were 0.826, 1.002, and 1.285; P were 0.003, 0.009, and 0.010), but not in participants without SDB. There was no interaction effect between DC, ANN, PNN50 and oxygen desaturation index. In hierarchical analysis, DC and ANN were predictors for CVD in SDB patients with age <60 years, male, overweight, diabetes, and normal lipid metabolism. PNN50 was predictor for CVD in the elderly SDB patients without overweight, diabetes or dyslipidemia.
CONCLUSIONS
PRV parameters may be specific predictors for CVD in SDB. PNN50 was a potent biomarker for CVD risk in the elderly with SDB, event without traditional CVD risk factors.
Topics: Humans; Male; Aged; Adult; Middle Aged; Cardiovascular Diseases; Polysomnography; Overweight; Heart Rate; Cross-Sectional Studies; Sleep Apnea Syndromes; Sleep; Diabetes Mellitus
PubMed: 37734671
DOI: 10.1016/j.rmed.2023.107408 -
PloS One 2023Heart failure is a chronic progressive disease in which the heart muscle is unable to pump enough blood to meet the body's need. It is a severe health problem around the...
INTRODUCTION
Heart failure is a chronic progressive disease in which the heart muscle is unable to pump enough blood to meet the body's need. It is a severe health problem around the world with high re-hospitalization and death rates. The main aim of this study was to identify the factors associated with longitudinal change of pulse rate and survival time to death of congestive heart failure patients treated at Arba Minch General Hospital.
METHODS
A retrospective study design was undertaken on congestive heart failure patients admitted to the Arba Minch General Hospital from January 2017 to December 2020. Data was collected from a total of 199 patients. After evaluating the longitudinal data with a linear mixed model and the survival time to death data with cox proportional model, Bayesian joint model of both sub models was fitted in R software using JMbayes2 package.
RESULTS
Findings from Bayesian joint model revealed that the estimated value for the association parameter was positive and statistically significant. This indicates that there is significant evidence of an association between the mean longitudinal change of pulse rate and the risk of death. Weight of patients at baseline, gender, chronic kidney disease, left ventricular ejection fraction, New York Heart Association classification, diabetes, tuberculosis, pneumonia and family history were statistically significant factors associated with mean evolution of pulse rate of congestive heart failure patients. Left ventricular ejection fraction, etiology of congestive heart failure, type of congestive heart failure, chronic kidney disease, smoking, family history, alcohol and diabetes were found to be statistically significant factors associated with survival time to death.
CONCLUSION
To reduce the risk level, health professionals should give attention to congestive heart failure patients with high pulse rate, co-morbidities of chronic kidney disease, tuberculosis, diabetic, smoking status, family history, and pneumonia in the study area.
Topics: Humans; Heart Rate; Bayes Theorem; Ethiopia; Hospitals, General; Retrospective Studies; Stroke Volume; Ventricular Function, Left; Heart Failure
PubMed: 36881600
DOI: 10.1371/journal.pone.0282637