How Nonlinear-Type Time-Frequency Analysis Can Help in Sensing Instantaneous Heart Rate and Instantaneous Respiratory Rate from Photoplethysmography in a Reliable Way

Cicone, Antonio; Wu, Hau‐Tieng

doi:10.3389/fphys.2017.00701

Cited by 36 publications

(29 citation statements)

References 60 publications

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“…2). [32][33][34] Traditionally, prominent features were derived from the tachogram (RR intervals) since it is a reliable measure of heart beats. 35 Realizing that PPG waveforms may carry physiological information beyond heart rate, new features beyond RR intervals were derived.…”

Section: Ppg-based Af Detectionmentioning

confidence: 99%

Photoplethysmography based atrial fibrillation detection: a review

et al. 2020

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Atrial fibrillation (AF) is a cardiac rhythm disorder associated with increased morbidity and mortality. It is the leading risk factor for cardioembolic stroke and its early detection is crucial in both primary and secondary stroke prevention. Continuous monitoring of cardiac rhythm is today possible thanks to consumer-grade wearable devices, enabling transformative diagnostic and patient management tools. Such monitoring is possible using low-cost easy-to-implement optical sensors that today equip the majority of wearables. These sensors record blood volume variations-a technology known as photoplethysmography (PPG)-from which the heart rate and other physiological parameters can be extracted to inform about user activity, fitness, sleep, and health. Recently, new wearable devices were introduced as being capable of AF detection, evidenced by large prospective trials in some cases. Such devices would allow for early screening of AF and initiation of therapy to prevent stroke. This review is a summary of a body of work on AF detection using PPG. A thorough account of the signal processing, machine learning, and deep learning approaches used in these studies is presented, followed by a discussion of their limitations and challenges towards clinical applications.npj Digital Medicine (2020) 3:3 ; https://doi.org/10.1038/s41746-019-0207-9 PHOTOPLETHYSMOGRAPHY PPG signal PPG waveform is generated during a cardiac cycle and typically measured at a peripheral site. Therefore, it is essentially a pulse pressure waveform that originates from the heart contraction and propagates through the vascular tree. As blood flow is controlled

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Section: Ppg-based Af Detectionmentioning

confidence: 99%

Photoplethysmography based atrial fibrillation detection: a review

et al. 2020

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“…Conventional respiration measurement approaches, including chest-belts or oronasal probes, are inconvenient to use. However, the latest progress in physiological measurement technology led to the development of novel, less obtrusive approaches based on standard one-lead ECG tracing [23], pulse oximetry [24], or thermal imaging [25] that allow for the real-time monitoring of respiration. These approaches may be potentially incorporated into handheld devices designed to deliver taVNS (e.g., NEMOS ® , cerbomed, Erlangen, Germany [26]).…”

Section: Cardiovascular Effects Of Respiratory-gated Tavnsmentioning

confidence: 99%

Inspiratory- and expiratory-gated transcutaneous vagus nerve stimulation have different effects on heart rate in healthy subjects: preliminary results

2019

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Purpose Transcutaneous auricular vagus nerve stimulation (taVNS) hasbeen considered for the treatment of sympathetically mediated disorders. However, the optimal mode of stimulation is unknown. This study aimed to compare the cardiovascular effects of respiratory-gated taVNS in healthy subjects. Methods The examination included expiratory-gated, inspiratory-gated, and non-respiratory-gated taVNS trials. Subjects were examined twice (the order of expiratory-and inspiratory-gated taVNS was changed). taVNS trials started with controlled breathing without stimulation (pre-stimulatory recording) followed by controlled breathing with taVNS (stimulatory recording). Synchronizing taVNS with the respiratory phase was computer-controlled. Heart rate (HR) was calculated from ECG. Systolic blood pressure (SBP) and systemic vascular resistance (SVR) were recorded continuously and noninvasively. Baroreflex sensitivity based on rising (BRS-UP) or falling SBP sequences (BRS-DOWN) or all sequences (BRS-ALL) and heart rate variability (HRV) were analyzed. Results Seventy-two taVNS trials were obtained from 12 subjects (age 23 ± 3 years). Pre-stimulatory HR correlated with change in HR (r = − 0.25) and SVR (r = 0.24, both p < 0.05). There were no differences between three stimulatory conditions in (1) the changes of hemodynamic parameters, (2) BRS-UP and BRS-ALL, or (3) HRV indices (all p > 0.20). However, in the group of high pre-stimulatory HR trials, HR change differed between inspiratory-gated (0.11 ± 0.53%) and both expiratorygated (− 1.30 ± 0.58%, p = 0.06) and non-respiratory-gated taVNS (− 1.69 ± 0.65, p = 0.02). BRS-DOWN was higher in inspiratory-vs. non-respiratory-gated taVNS (15.4 ± 1.3 vs. 14.1 ± 0.9 ms/mmHg, p = 0.03). Conclusions Expiratory-gated and non-respiratory-gated taVNS exert clear cardioinhibitory effects in healthy subjects with high pre-stimulatory HR, whereas inspiratory-gated taVNS does not affect HR. Cardiac and vascular effects of taVNS depend on pre-stimulatory HR.

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“…Cicone and Wu [18] also focus on obtaining a more reliable method for extracting respiratory rate. In this case the authors apply theoretically solid techniques of nonlineartype time-frequency analyses, like the de-shape short time Fourier transform and the synchrosqueezing transform, which allows the estimation of respiratory rate with higher reliability.…”

Section: Previous Workmentioning

confidence: 99%