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Sensors (Basel, Switzerland) Jul 2023Not long ago, hearables paved the way for biosensing, fitness, and healthcare monitoring. Smart earbuds today are not only producing sound but also monitoring vital... (Review)
Review
Not long ago, hearables paved the way for biosensing, fitness, and healthcare monitoring. Smart earbuds today are not only producing sound but also monitoring vital signs. Reliable determination of cardiovascular and pulmonary system information can explore the use of hearables for physiological monitoring. Recent research shows that photoplethysmography (PPG) signals not only contain details on oxygen saturation level (SPO2) but also carry more physiological information including pulse rate, respiration rate, blood pressure, and arterial-related information. The analysis of the PPG signal from the ear has proven to be reliable and accurate in the research setting. (1) Background: The present integrative review explores the existing literature on an in-ear PPG signal and its application. This review aims to identify the current technology and usage of in-ear PPG and existing evidence on in-ear PPG in physiological monitoring. This review also analyzes in-ear (PPG) measurement configuration and principle, waveform characteristics, processing technology, and feature extraction characteristics. (2) Methods: We performed a comprehensive search to discover relevant in-ear PPG articles published until December 2022. The following electronic databases: Institute of Electrical and Electronics Engineers (IEEE), ScienceDirect, Scopus, Web of Science, and PubMed were utilized to conduct the studies addressing the evidence of in-ear PPG in physiological monitoring. (3) Results: Fourteen studies were identified but nine studies were finalized. Eight studies were on different principles and configurations of hearable PPG, and eight studies were on processing technology and feature extraction and its evidence in in-ear physiological monitoring. We also highlighted the limitations and challenges of using in-ear PPG in physiological monitoring. (4) Conclusions: The available evidence has revealed the future of in-ear PPG in physiological monitoring. We have also analyzed the potential limitation and challenges that in-ear PPG will face in processing the signal.
Topics: Photoplethysmography; Monitoring, Physiologic; Blood Pressure; Arteries; Respiratory Rate; Heart Rate; Signal Processing, Computer-Assisted
PubMed: 37514778
DOI: 10.3390/s23146484 -
Medical & Biological Engineering &... Oct 2023Remote photoplethysmography (rPPG) enables contact-free monitoring of the pulse rate by using a color camera. The fundamental limitation is that motion artifacts and...
Remote photoplethysmography (rPPG) enables contact-free monitoring of the pulse rate by using a color camera. The fundamental limitation is that motion artifacts and changes in ambient light conditions greatly affect the accuracy of pulse-rate monitoring. We propose use of a high-speed camera and a motion suppression algorithm with high computational efficiency. This system incorporates a number of major improvements including reproduction of pulse wave details, high-precision pulse-rate monitoring of moving subjects, and excellent scene scalability. A series of quantization methods were used to evaluate the effect of different frame rates and different algorithms in pulse-rate monitoring of moving subjects. The experimental results show that use of 180-fps video and a Plane-Orthogonal-to-Skin (POS) algorithm can produce high-precision pulse-rate monitoring results with mean absolute error can be less than 5 bpm and the relative accuracy reaching 94.5%. Thus, it has significant potential to improve personal health care and intelligent health monitoring.
Topics: Humans; Heart Rate; Pulse; Skin; Photoplethysmography; Motion; Algorithms; Signal Processing, Computer-Assisted
PubMed: 37474842
DOI: 10.1007/s11517-023-02884-1 -
Clinical Autonomic Research : Official... Dec 2023Increasing evidence demonstrates that gender-related factors, and not only biological sex, are relevant in the physiological and pathophysiological mechanisms of the... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
Increasing evidence demonstrates that gender-related factors, and not only biological sex, are relevant in the physiological and pathophysiological mechanisms of the cardiovascular system, including the cardiac autonomic regulation. Sex and gender may also affect daytime and night-time cardiac autonomic control. This meta-analysis aimed to provide a comparison between healthy women and men on heart rate variability using 24-h ECG recordings pointing out sex- and gender-related factors.
METHODS
A systematic search was conducted to include studies focusing on both sex and gender differences related to heart rate variability indices in the time and frequency domains. Descriptive data were extracted by two independent reviewers. For each index, standardized mean differences with 95% confidence intervals were computed and a pooled estimate using a fixed- or random-effects model was applied.
RESULTS
Twenty-seven studies were included in the meta-analysis. The results showed that only seven studies reported some information about gender-related factors. Concerning sex-related differences, women had a shorter mean RR interval and lower variability of the time domain indices than men. Sex-related differences concerning frequency domain indices were more evident during night-time compared to daytime.
CONCLUSION
The characterization of gender-related factors in the study of heart rate variability using 24-h ECG recordings is still sporadic and underexplored. The meta-analysis results could not conclusively support a significant increase of high frequency power in women, although women showed a reduced total power and low frequency to high frequency ratio. There is a strong need for considering heart rate variability in relation to gender-related variables.
Topics: Male; Humans; Female; Heart Rate; Heart; Autonomic Nervous System; Sex Factors; Electrocardiography
PubMed: 37541968
DOI: 10.1007/s10286-023-00969-3 -
Methods (San Diego, Calif.) Oct 2023Heart rate variability (HRV) is an important indicator of autonomic nervous system activity and can be used for the identification of affective states. The development...
Heart rate variability (HRV) is an important indicator of autonomic nervous system activity and can be used for the identification of affective states. The development of remote Photoplethysmography (rPPG) technology has made it possible to measure pulse rate variability (PRV) using a camera without any sensor-skin contact, which is highly correlated to HRV, thus, enabling contactless assessment of emotional states. In this study, we employed ten machine learning techniques to identify emotions using camera-based PRV features. Our experimental results show that the best classification model achieved a coordination correlation coefficient of 0.34 for value recognition and 0.36 for arousal recognition. The rPPG-based measurement has demonstrated promising results in detecting HAHV (high-arousal high-valence) emotions with high accuracy. Furthermore, for emotions with less noticeable variations, such as sadness, the rPPG-based measure outperformed the baseline deep network for facial expression analysis.
Topics: Heart Rate; Emotions; Machine Learning; Skin
PubMed: 37678514
DOI: 10.1016/j.ymeth.2023.08.014 -
Frontiers in Public Health 2023Chronic stress has become an epidemic with negative health risks including cardiovascular disease, hypertension, and diabetes. Traditional methods of stress measurement...
Chronic stress has become an epidemic with negative health risks including cardiovascular disease, hypertension, and diabetes. Traditional methods of stress measurement and monitoring typically relies on self-reporting. However, wearable smart technologies offer a novel strategy to continuously and non-invasively collect objective health data in the real-world. A novel electrocardiogram (ECG) feature has recently been introduced to the Apple Watch device. Interestingly, ECG data can be used to derive Heart Rate Variability (HRV) features commonly used in the identification of stress, suggesting that the Apple Watch ECG app could potentially be utilized as a simple, cost-effective, and minimally invasive tool to monitor individual stress levels. Here we collected ECG data using the Apple Watch from 36 health participants during their daily routines. Heart rate variability (HRV) features from the ECG were extracted and analyzed against self-reported stress questionnaires based on the DASS-21 questionnaire and a single-item LIKERT-type scale. Repeated measures ANOVA tests did not find any statistical significance. Spearman correlation found very weak correlations ( < 0.05) between several HRV features and each questionnaire. The results indicate that the Apple Watch ECG cannot be used for quantifying stress with traditional statistical methods, although future directions of research (e.g., use of additional parameters and Machine Learning) could potentially improve stress quantification with the device.
Topics: Humans; Heart Rate; Electrocardiography; Wearable Electronic Devices; Cardiovascular Diseases; Hypertension
PubMed: 37475772
DOI: 10.3389/fpubh.2023.1178491 -
Annual International Conference of the... Jul 2023Vital sign monitoring is an invaluable tool for healthcare professionals, both in the hospital and at home. Traditional measurement devices provide accurate readings but...
Vital sign monitoring is an invaluable tool for healthcare professionals, both in the hospital and at home. Traditional measurement devices provide accurate readings but require physical contact with the patient which often is unsuitable, furthermore contact-based devices have been reported to fail by loosing contact due to movement as severe events occur, therefore, a contactless method is necessary.We hypothesize that, in ideal scenarios, it is possible to estimate both SpO and pulse rate using only facial video recorded with a smartphone's front-facing camera. To test this hypothesis, a dataset of 10 healthy subjects performing various breathing patterns while being recorded with a smartphone camera was collected during ideal lighting conditions.Using advanced image and signal processing methods to acquire remote photoplethysmography (rPPG) estimates from a patient's forehead, our proposed method can achieve SpO estimation results with A = 1.34% (accuracy RMS) and MAE ± STD = 1.26 ± 0.68% (mean average error) across a SpO range of 92% to 99% (percentage point SpO) and pulse rate estimation results with A = 3.91 bpm (beats per minute) and MAE ± STD = 3.24±2.11 bpm across a pulse rate range of 60 bpm to 90 bpm. We conclude from these results, that remote vital sign estimation using facial videos recorded entirely with a smartphone camera is possible.
Topics: Humans; Heart Rate; Smartphone; Oxygen Saturation; Face; Signal Processing, Computer-Assisted
PubMed: 38083785
DOI: 10.1109/EMBC40787.2023.10340995 -
Acta Cardiologica Aug 2023The role of the autonomic nervous system in the onset of supraventricular and ventricular arrhythmias is well established. It can be analysed by the spontaneous... (Review)
Review
The role of the autonomic nervous system in the onset of supraventricular and ventricular arrhythmias is well established. It can be analysed by the spontaneous behaviour of the heart rate with ambulatory ECG recordings, through heart rate variability measurements. Input of heart rate variability parameters into artificial intelligence models to make predictions regarding the detection or forecast of rhythm disorders is becoming routine and neuromodulation techniques are now increasingly used for their treatment. All this warrants a reappraisal of the use of heart rate variability for autonomic nervous system assessment.Measurements performed over long periods such as 24H-variance, total power, deceleration capacity, and turbulence are suitable for estimating the individual basal autonomic status. Spectral measurements performed over short periods provide information on the dynamics of systems that disrupt this basal balance and may be part of the triggers of arrhythmias, as well as premature atrial or ventricular beats. All heart rate variability measurements essentially reflect the modulations of the parasympathetic nervous system which are superimposed on the impulses of the adrenergic system. Although heart rate variability parameters have been shown to be useful for risk stratification in patients with myocardial infarction and patients with heart failure, they are not part of the criteria for prophylactic implantation of an intracardiac defibrillator, because of their high variability and the improved treatment of myocardial infarction. Graphical methods such as Poincaré plots allow quick screening of atrial fibrillation and are set to play an important role in the e-cardiology networks. Although mathematical and computational techniques allow manipulation of the ECG signal to extract information and permit their use in predictive models for individual cardiac risk stratification, their explicability remains difficult and making inferences about the activity of the ANS from these models must remain cautious.
Topics: Humans; Heart Rate; Artificial Intelligence; Autonomic Nervous System; Heart; Myocardial Infarction; Atrial Fibrillation; Heart Atria
PubMed: 36803313
DOI: 10.1080/00015385.2023.2177371 -
Journal of Sports Sciences Sep 2023Differences in workload exist between netball playing positions and competition levels, but no research has compared workloads experienced by the same elite players...
Differences in workload exist between netball playing positions and competition levels, but no research has compared workloads experienced by the same elite players during national and international competitions. This study collected internal (heart rate) and external (PlayerLoad·min) workload data per match quarter from 44 players during a national competition and 12 players during an international competition. Nine players played in both competitions. Linear mixed models compared percentage of match quarter in each heart rate zone and PlayerLoad·min between competitions for each playing position. Workloads against low- and high-ranked international opponents were also compared. Internal workloads were greater in national compared to international competition for GD and WD positions. PlayerLoad·min was significantly higher by 8-13% in the national competition for positions WD and C, and by 5-8% in the international competition for GD and GA. Positional differences may indicate a role of the team's tactical style of play. Workloads were generally greater against higher- rather than lower-ranked international opponents. These results indicate that tactical factors in combination with playing position and opposition characteristics should be considered when preparing physically for matches.
Topics: Humans; Basketball; Workload; Athletic Performance; Heart Rate; Linear Models
PubMed: 38078436
DOI: 10.1080/02640414.2023.2283661 -
Seminars in Cell & Developmental Biology Mar 2024The parasympathetic nervous system via the vagus nerve exerts profound influence over the heart. Together with the sympathetic nervous system, the parasympathetic... (Review)
Review
The parasympathetic nervous system via the vagus nerve exerts profound influence over the heart. Together with the sympathetic nervous system, the parasympathetic nervous system is responsible for fine-tuned regulation of all aspects of cardiovascular function, including heart rate, rhythm, contractility, and blood pressure. In this review, we highlight vagal efferent and afferent innervation of the heart, with a focus on insights from comparative biology and advances in understanding the molecular and genetic diversity of vagal neurons, as well as interoception, parasympathetic dysfunction in heart disease, and the therapeutic potential of targeting the parasympathetic nervous system in cardiovascular disease.
Topics: Humans; Vagus Nerve; Heart; Heart Rate; Heart Diseases; Clinical Medicine
PubMed: 36641366
DOI: 10.1016/j.semcdb.2023.01.001 -
Scientific Reports Sep 2023To determine the effects of intense training on aortic pulse wave variables and hemodynamic parameters at baseline and at recovery from maximal exercise testing (MaxET)...
To determine the effects of intense training on aortic pulse wave variables and hemodynamic parameters at baseline and at recovery from maximal exercise testing (MaxET) in triathletes compared with sedentary individuals. In this prospective and experimental study, 21 triathletes and 21 sedentary individuals were recruited and evaluated prior and two minutes after the MaxET using the Mobil-O-Graph®, which estimates the aortic pulse wave from the brachial artery pressure. The augmentation index (AIx@75) was lower in triathletes after the MaxET compared to control group (16.34 ± 5.95 vs. 23.5 ± 8.53%, p = 0.001), while the pulse wave velocity (PWV) was similar between groups. The heart rate was significantly lower at baseline and after MaxET in triathletes group (55.70 ± 8.95 bpm 91.49 ± 11.39 bpm) compared with control group (62.11 ± 6.70 bpm; 102.08 ± 10.85 bpm). The stroke volume was significantly higher at baseline (96.08 ± 13.96 ml; 86.17 ± 11.24 ml) and after MaxET in triathletes group (69.15 ± 6.51 ml, 58.38 ± 6.99 ml) compared with control group. Triathetes show lower value of AIx@75 after MaxET in comparison with the control group. AIx@75, in addition to being an indirect measure of arterial stiffness, is also a measure of left ventricular afterload. Thus, the lower AIx@75 in triathletes may be due to their lower left ventricular afterload, lower myocardial oxygen demand, and greater coronary perfusion than sedentary individuals. The hemodynamic changes observed in triathletes at rest and during an acute exercise bout are distinctive characteristics of aerobic physical training.
Topics: Humans; Heart Rate; Prospective Studies; Pulse Wave Analysis; Vascular Stiffness; Exercise
PubMed: 37741959
DOI: 10.1038/s41598-023-43303-7