scholarly journals Characterizing the Human Heart Rate Circadian Pacemaker through Widely Available Wearable Devices

2020 ◽  
Author(s):  
Clark Bowman ◽  
Yitong Huang ◽  
Olivia J Walch ◽  
Yu Fang ◽  
Elena Frank ◽  
...  
Keyword(s):  
Heart Rate ◽  
Circadian Rhythm ◽  
Real World ◽  
Phase Response Curve ◽  
Practical Method ◽  
Sleep Time ◽  
Real World Data ◽  
Wake Time ◽  
Medical Interns

SummaryThe effects of real-world stimuli and how they vary across individuals remains largely unknown for lack of a continuous real-world circadian marker. Here, we show how an underlying circadian rhythm in heart rate (CRHR) can be extracted from several widely used wearables. Analysis of over 130,000 days of data from medical interns on rotating shifts shows how CRHR dynamics are distinct from those of sleep-wake timing and vary greatly among individuals. Analysis of circadian timekeeping in travelers in 5 continents shows how the circadian timekeeping more carefully controls wake time rather than sleep time. We determine a personalized phase response curve (PRC) of CRHR to activity for each individual, representing the first passive and personalized determination of how human circadian timekeeping continuously changes due to real-world stimuli. These results collectively establish CRHR as a practical method to study circadian rhythms in the real world.eTOC BlurbWe show how the circadian rhythm in heart rate can be extracted from real world data collected by wearables. Studying data from a large cohort of medical interns working on shifts, we find very interesting dynamics of this circadian rhythm that are independent of the acute effects of activity or sleep-wake timing. These techniques can also determine personalized parameters of circadian timekeeping.

scholarly journals How stress affects sleep and mental health: nocturnal heart rate increases during prolonged stress and interacts with childhood trauma exposure to predict anxiety

SLEEP ◽  
2019 ◽  
Vol 43 (6) ◽  
Author(s):  
Yasmine Azza ◽  
Marcus Grueschow ◽  
Walter Karlen ◽  
Erich Seifritz ◽  
Birgit Kleim
Keyword(s):  
Heart Rate ◽  
Childhood Trauma ◽  
Real World ◽  
Multilevel Models ◽  
Trauma Exposure ◽  
Sleep Time ◽  
Stress Exposure ◽  
Intervention Measures ◽  
Development Of Anxiety ◽  
Prolonged Stress

Abstract Study Objectives Stress can adversely impact sleep health by eliciting arousal increase and a cascade of endocrine reactions that may impair sleep. To date, little is known regarding continuous effects of real-world stress on physiological sleep characteristics and potential effects on stress-related psychopathology. We examined effects of stress on heart rate (HR) during sleep and total sleep time (TST) during prolonged real-world stress exposure in medical interns. Moreover, we investigated the influence of previous stress and childhood trauma exposure on HR during sleep, TST, and its interaction in predicting anxiety. Methods We examined a sample of 50 medical students prior to and during their first internship, a well described real-world stressor. HR and TST were continuously collected over 12 weeks non-invasively by a wrist-worn activity monitor. Prior to starting the internship, at baseline, participants reported on their sleep, anxiety, and childhood trauma exposure. They also tracked stress exposure during internship and reported on their anxiety symptoms 3 months after this professional stress. Results Mean HR during sleep increased over time, while TST remained unchanged. This effect was more pronounced in interns exposed to childhood trauma exposure. In multilevel models, childhood trauma exposure also moderated the relation between individual HR increase and development of anxiety. Conclusions Prolonged stress may lead to increased HR during sleep, whereas individuals with childhood trauma exposure are more vulnerable. Childhood trauma exposure also moderated the relation between individual HR increase and development of anxiety. These findings may inform prevention and intervention measures.

scholarly journals The everyday acoustic environment and its association with human heart rate: evidence from real-world data logging with hearing aids and wearables

2020 ◽  
Author(s):  
Jeppe H. Christensen ◽  
Gabrielle H. Saunders ◽  
Michael Porsbo ◽  
Niels H. Pontoppidan
Keyword(s):  
Heart Rate ◽  
Hearing Aids ◽  
Real World ◽  
Data Logging ◽  
Environmental Sound ◽  
Real World Data ◽  
Heart Rates ◽  
World Data ◽  
Ambient Sound ◽  
Mean Heart Rate

AbstractWe investigate the longitudinal association between multidimensional characteristics of everyday ambient sound and continuous mean heart rate. We used in-market data from hearing aid users who logged ambient acoustics via smartphone-connected hearing aids and continuous heart rate from their own wearables.We find that ambient acoustic characteristics explain approximately 4% of the fluctuation in mean heart rate throughout the day. Specifically, increases in ambient sound pressure intensity are significantly related to increases in mean heart rates, corroborating prior laboratory and short-term real-world data. In addition, however, and not previously recognized, increases in the ambient sound quality - that is, the difference between sound signal and noise - are associated with decreases in mean heart rates.Our findings document a mixed influence of everyday sounds on cardiovascular stress, and that the relationship is more complex than is seen from examination of sound intensity alone. Thus, our findings highlight the relevance of ambient environmental sound in models of human ecophysiology.

scholarly journals The everyday acoustic environment and its association with human heart rate: evidence from real-world data logging with hearing aids and wearables

2021 ◽  
Vol 8 (2) ◽  
pp. 201345
Author(s):  
Jeppe H. Christensen ◽  
Gabrielle H. Saunders ◽  
Michael Porsbo ◽  
Niels H. Pontoppidan
Keyword(s):  
Heart Rate ◽  
Hearing Aids ◽  
Real World ◽  
Data Logging ◽  
Short Term ◽  
Real World Data ◽  
Acoustic Characteristics ◽  
World Data ◽  
Ambient Sound ◽  
Mean Heart Rate

We investigate the short-term association between multidimensional acoustic characteristics of everyday ambient sound and continuous mean heart rate. We used in-market data from hearing aid users who logged ambient acoustics via smartphone-connected hearing aids and continuous mean heart rate in 5 min intervals from their own wearables. We find that acoustic characteristics explain approximately 4% of the fluctuation in mean heart rate throughout the day. Specifically, increases in ambient sound pressure intensity are significantly related to increases in mean heart rate, corroborating prior laboratory and short-term real-world data. In addition, increases in ambient sound quality—that is, more favourable signal to noise ratios—are associated with decreases in mean heart rate. Our findings document a previously unrecognized mixed influence of everyday sounds on cardiovascular stress, and that the relationship is more complex than is seen from an examination of sound intensity alone. Thus, our findings highlight the relevance of ambient environmental sound in models of human ecophysiology.

scholarly journals The problem of causality in corporate governance research: The case of governance indexes and firm valuation

2017 ◽  
Vol 13 (2) ◽  
pp. 55-60 ◽  
Author(s):  
Jimmy A. Saravia Matus ◽  
Silvia L. Saravia-Matus
Keyword(s):  
Corporate Governance ◽  
Causal Relationship ◽  
Real World ◽  
Traditional Approach ◽  
Contemporary Literature ◽  
Current Approach ◽  
Firm Valuation ◽  
Real World Data ◽  
Logical Fallacy

In recent years the problem of the determination of causality has become an increasingly important question in the field of corporate governance. This paper reviews contemporary literature on the topic of causality, specifically it examines the literature that investigates the causal relationship between corporate governance indexes and firm valuation and finds that the current approach is to attempt to determine causality empirically and that the problem remains unresolved. After explaining the reasons why it is not possible to attempt to determine causality using real world data without falling prey to a logical fallacy, this paper discusses a traditional approach used in science to deal with the problem. In particular, the paper argues that the appropriate approach for the problem is to build theories, with causality featuring as a part of those theories, and then to test those theories both for logical and empirical consistency.

scholarly journals Personalized sleep-wake patterns aligned with circadian rhythm relieve daytime sleepiness

2021 ◽  
Author(s):  
Jaehyoung Hong ◽  
Su Jung Choi ◽  
Se Ho Park ◽  
Hyukpyo Hong ◽  
Victoria Booth ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Real World ◽  
Daytime Sleepiness ◽  
Total Sleep Time ◽  
Sleep Time ◽  
Wearable Devices ◽  
Shift Workers ◽  
Wake Patterns ◽  
Sleep Parameters ◽  
User Friendly

Shift workers and many other groups experience irregular sleep-wake patterns. This can induce excessive daytime sleepiness that decreases productivity and elevates the risk of accidents. However, the degree of daytime sleepiness is not correlated with standard sleep parameters like total sleep time, suggesting other factors are involved. Here, we analyze real-world sleep-wake patterns of shift workers measured by wearables with a newly developed user-friendly computational package that simulates homeostatic sleep pressure - the physiological need for sleep - and the circadian rhythm. This reveals that shift workers who align sleep-wake patterns with their circadian rhythm have lower daytime sleepiness, even if they sleep less. The alignment, quantified by a new parameter, circadian sleep sufficiency, can be increased by dynamically adjusting daily sleep durations according to varying bedtimes. Our computational package provides flexible and personalized real-time sleep-wake patterns for individuals to reduce their daytime sleepiness and could be used with wearable devices to develop smart alarms.

scholarly journals Validation of the Mobile App–Recorded Circadian Rhythm by a Digital Footprint (Preprint)

2019 ◽  
Author(s):  
Yu-Hsuan Lin ◽  
Bo-Yu Wong ◽  
Yuan-Chien Pan ◽  
Yu-Chuan Chiu ◽  
Yang-Han Lee
Keyword(s):  
Circadian Rhythm ◽  
Sleep Onset ◽  
Sleep Time ◽  
Mobile App ◽  
Wake Time ◽  
Social Jetlag ◽  
Significant Difference ◽  
Recorded Data ◽  
Smartphone Use

BACKGROUND Modern smartphone use is pervasive and could be an accessible method of evaluating the circadian rhythm and social jet lag via a mobile app. OBJECTIVE This study aimed to validate the app-recorded sleep time with daily self-reports by examining the consistency of total sleep time (TST), as well as the timing of sleep onset and wake time, and to validate the app-recorded circadian rhythm with the corresponding 30-day self-reported midpoint of sleep and the consistency of social jetlag. METHODS The mobile app, Rhythm, recorded parameters and these parameters were hypothesized to be used to infer a relative long-term pattern of the circadian rhythm. In total, 28 volunteers downloaded the app, and 30 days of automatically recorded data along with self-reported sleep measures were collected. RESULTS No significant difference was noted between app-recorded and self-reported midpoint of sleep time and between app-recorded and self-reported social jetlag. The overall correlation coefficient of app-recorded and self-reported midpoint of sleep time was .87. CONCLUSIONS The circadian rhythm for 1 month, daily TST, and timing of sleep onset could be automatically calculated by the app and algorithm.

635 Evening Sunglasses Plus Stable Wake Times: Can This Intervention Help Adolescents with Delayed Sleep-wake Phase Disorder?

SLEEP ◽  
2021 ◽  
Vol 44 (Supplement_2) ◽  
pp. A249-A249
Author(s):  
Stephanie Crowley ◽  
Logan Killen ◽  
R Robert Auger
Keyword(s):  
Phase Response Curve ◽  
Light Exposure ◽  
Sleep Onset ◽  
Sleep Time ◽  
Night Sleep ◽  
Wake Time ◽  
Sleep Diaries ◽  
Research Award ◽  
Wrist Actigraphy ◽  
Delayed Sleep

Abstract Introduction Evening light can increase alertness and shift the circadian clock later (delay) and, in turn, delay sleep onset timing. We are examining whether reducing evening light exposure (by wearing sunglasses) paired with stable wake times can shift circadian and sleep onset times earlier in adolescents with Delayed Sleep-Wake Phase Disorder (DSWPD). Methods Fifteen adolescents (14.7–18.1 years; 4 male) diagnosed with DSWPD are included in this interim analysis. Participants sleep without restriction at home for a baseline week, and then complete a 2-week intervention. One group (Amber; n=7) wears glasses with amber lenses (Cocoons®, Live Eyewear) beginning 7 hours before their baseline mid-sleep time until self-selected bedtime or for 7 hours (corresponds to the phase delay region of the adolescent phase response curve to light). The amber lens transmits 14% of light to the eye and absorbs most short wavelength light. The frame blocks light from all angles. Amber participants are also instructed to wake at their average baseline school-morning wake-up time (±30 mins). Another group (Clear; n=8) wears identical glasses with clear lenses at the same time and wake time is unrestricted. Glasses wear time is monitored with an iButton placed at the temple tip. Dim Light Melatonin Onset (DLMO) is measured after the baseline week and after the 2-week intervention; 2 participants (one from each group) do not have melatonin data due to technical error. Sleep is measured with wrist actigraphy and sleep diaries throughout the study. DLMO and sleep onset changes (baseline-intervention) are compared between groups with t-tests. Results Amber DLMOs shifted 1.0±2.0h earlier (min-max: 0.4-h delay-5.0-h advance) and Clear DLMOs shifted 0.4±1.1h later (min-max: 2.0-h delay-0.6-h advance) [t(11)=1.60,p=0.14]. Average school-night sleep onset shifted earlier in both groups (Amber:0.4±1.3h; Clear:0.6±1.0h; t(13)=0.2,p=0.8]. Average non-school-night sleep onset shifted 1.1±1.0h earlier in Amber (min-max:0.6-h delay-2.2-h advance) and remained stable (0.03±1.0h) in Clear (min-max: 1.8-h delay-1.7-h advance) [t(13)=1.92,p=.08]. Conclusion Trends from this ongoing study suggest that amber-lensed glasses to block evening light plus stable wake-up times may shift circadian rhythms earlier. This strategy appears to help adolescents with DSWPD fall asleep earlier predominantly on non-school nights. Support (if any) AASMF Strategic Research Award (184-SR-17) to RRA

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