Anda Baharav

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R wave duration as a measure of body position changes during sleep

by Zvi Shinar and Anda Baharav

Computers in Cardiology 1999. Vol.26 (Cat. No.99CH37004), 1999

Any change in body position alters the relative angle between the ECG electrodes and the electric... more Any change in body position alters the relative angle between the ECG electrodes and the electric axis of the heart. Thus it influences the time interval during which the projection of the electric dipole, on any ECG lead is positive. We used the R wave duration (RWD) as representing this positive projection and as indicator of body position changes. Two experimental setups were used: (1) Simultaneous ECG recordings from leads I, II, and III during a sequence of well-defined body positions, (controlled conditions). (2) Lead II and video recordings from healthy subjects, who underwent whole night sleep studies. Using data of any of the leads, we could identify over 90% of the changes in body position, in both experimental setups. RWD calculated from lead II was the most reproducible upon reassuming the same body position. Measuring RWD from ECG may help to reduce the number of sensors required in full sleep studies, and to obtain better interpretation of non-attended ones

0507 Mobile Cognitive Behavioral Therapy is Efficient in Improving Sleep in Students

Sleep, 2020

Introduction Academic achievements and social life on campus represent the main focus for student... more Introduction Academic achievements and social life on campus represent the main focus for students, while sleep is neglected. The emergence of social media, gaming reduces sleep opportunity, quality and ability. Students are sleep challenged and prone to develop chronic sleep difficulties in later life. Cognitive behavioral interventions are recognized as effective for insomnia and circadian misalignment. We aimed at detecting sleep difficulties, related habits, and at testing the efficacy of a mobile app in improving sleep in students with insomnia symptoms. Methods Observational study of US students who approached wellness staff and were offered the Refresh by Sleeprate mobile app that provides a sleep assessment followed by weekly cycles of personalized digital cognitive and behavioral reframing. The app collects perceived, and optional objective sleep data acquired using wearable devices. 892 students aged 18-30 years registered an account between Jan 1 and Oct 30, 2019. The stu...

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240 Habitual Sleep Changes Following COVID-19 Outbreak

Sleep, 2021

Introduction The ongoing COVID-19 pandemic emerges as one of the most impressive and strenuous ev... more Introduction The ongoing COVID-19 pandemic emerges as one of the most impressive and strenuous events of the century, with unthinkably huge global effects. We aimed at analyzing if and how does the pandemic affect sleep and related behaviors. Methods We reviewed 48,047 nights recorded in the US with the Sleeprate application by 3,381 users during a period of 2 years, December 2018-November 2020. Nightly data included perceived and measured sleep parameters. In addition, users reported their perceived daytime stress and sleepiness. We analyzed the monthly variability of the studied parameters and compared their values during the COVID-19 period of March-November 2020 (CP) with those in the previous corresponding period in 2019, the pre-COVID-19 period (PCP). Results Starting March 2020, wake-up time (WUT) was significantly delayed relative to PCP. WUT in April 2020 was the latest (8:06AM±2:12hours, mean±SD, p<.000), being an hour later than in April 2019. This delay started to dim...

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314 Alcohol and the Sleep of Elite Athletes

Sleep, 2021

Extensive evidence indicates that alcohol adversely affects athletic performance, increases the c... more Extensive evidence indicates that alcohol adversely affects athletic performance, increases the chance of injury, impairs aerobic metabolism, and has detrimental psychological influence. Alcohol consumption was also shown to be significant in young adults, with many elite athletes reporting alcohol intake. Sleep is essential to musculoskeletal recovery, acquisition of new skills, and emotional regulation in athletes. As insufficient sleep has detrimental effects on athletic performances and increases the risk of injury, we aimed to analyze the relation between alcohol consumption and sleep parameters among elite athletes. We studied 9,164 nights recorded with the Boost application by 66 adult elite athletes from various sports during October 2019-December 2020. In addition to perceived and measured sleep parameters, nightly data included the previous day reported alcohol consumption and the number of training sessions. For each athlete, the average nightly mean heart rate (HR) in ni...

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Sleep Duration Impact on Elite Young Athletes

Medicine & Science in Sports & Exercise, 2015

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Autonomic changes during wake–sleep transition: A heart rate variability based approach

Autonomic Neuroscience, 2006

Autonomic function during sleep and wakefulness has been extensively investigated, however inform... more Autonomic function during sleep and wakefulness has been extensively investigated, however information concerning autonomic changes during the wake to sleep transition is scarce. The objective of the present study was to non-invasively characterize autonomic function and additional physiologic changes during sleep onset in normal and abnormal sleep. The estimation of autonomic function was based on timefrequency analysis of the RR interval series, using the power components in the very-low-frequency range (0.005-0.04 Hz), low-frequency (0.04-0.15 Hz), and high-frequency range (0.15-0.5 Hz). The ratio of low to high frequency power represented the sympathovagal balance. Thirty-four subjects who underwent whole night polysomnography were divided into 3 groups according to their complaints and study results: normal subjects, apneic patients (OSAS), and subjects with various sleep disorders (VSD). The results indicated a significant increase in RR interval during sleep onset, although its variability decreased; respiratory rate did not change, yet respiration became more stable; EMG amplitude and its variability decreased with sleep onset. Very-low-frequency power started to decrease significantly 2 min before sleep onset in all groups; low-frequency power decreased and high-frequency power did not change significantly in all groups, accordingly their ratio decreased and reflected a shift towards parasympathetic predominance. Although autonomic function displayed similar behavior in all subjects, OSAS and VSD patients presented a higher sympathovagal balance reflecting enhanced sympathetic predominance in those groups compared to normal subjects, both before and after sleep onset. All parameters reached a nadir at a defined time point during the process of falling asleep. We conclude that the wake-sleep transition period represents a transitional process between two physiologically different states; this transition starts with a decrease in the very slow oscillations in heart rate that anticipates a step-change resetting of autonomic function, followed by a decrease in sympathovagal balance towards the end of the process.

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Sleep in the cloud: On how to use available heart rate monitors to track sleep and improve quality of life

As the modern society accumulates sleep debt that jeopardizes health, performance and wellbeing, ... more As the modern society accumulates sleep debt that jeopardizes health, performance and wellbeing, people become increasingly interested in self-assessment. We aim to enable sleep self-evaluation using available Heart Rate (HR) monitors, mobile and cloud technology. Sleep was evaluated using a proprietary ECG-based validated sleep diagnostic software adapted to HR data obtained from HR monitor belts (HRMs) which are widely used to monitor HR during physical activity. Data were transmitted and stored on an iPhone, using a dedicated application. Two wireless communication channels are used for HRMs: (P1) Wearlink and (P2) ANT+. The stored information was uploaded to the cloud and automatically analyzed. The functionality of an automated sleep monitoring and analysis, using HRMs, with either P1 or P2 transmission, iPhone, and cloud based SleepRate software analysis has been checked. HR belts with ANT+ were the most suitable for recording HR during sleep. Millions of people own HRMs to as...

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Impaired autonomic balance during sleep in obstructive sleep apnea: origin or result

Computers in Cardiology 2001. Vol.28 (Cat. No.01CH37287), 2001

The ECG may be used as a means to uncover information on the function of organs and systems apart... more The ECG may be used as a means to uncover information on the function of organs and systems apart from the heart itself. We studied the autonomic function in adult patients with obstructive sleep apnea syndrome (OSAS) and expected their autonomic balance to be shifted towards sympathetic predominance. The study included 12 OSAS patients and 12 subjects with no respiratory disturbance during sleep, as diagnosed by attended whole-night polysomnography (PSG) and scored according to standard criteria. The time-frequency decomposition of beat-to-beat heart rate variability (HRV), detected from the ECG, served to evaluate autonomic function. The results showed an overall increased sympathetic activity during sleep and sympathetic predominance during slow-wave sleep (SWS) in patients, as compared to control subjects. The degree of sympathetic predominance correlated well with the severity of sleep apnea.

Sleep Insights from the Finger Tip: How Photoplethysmography Can Help Quantify Sleep

2017 Computing in Cardiology Conference (CinC), Sep 14, 2017

Sleep is essential for a healthy and productive life, yet its importance is largely overlooked, a... more Sleep is essential for a healthy and productive life, yet its importance is largely overlooked, allowing populations to sleep less and to develop sleep disturbances. This trend results into an epidemic of poor quality and insufficient sleep that is turn jeopardizes health, performance, mood, memory, social relationships and productivity. A first step to overcome this epidemic relies on uncovering it at the individual and societal levels. The availability of different wearable devices that can track physiological signals represents a great opportunity to define and quantify the problem. Many such devices incorporate a photoplethysmography (PPG) sensor. This triggers interest in studies aiming to get insight into human sleep structure based on information obtained from PPG sensors. This study aimed to validate a new automated sleep analysis which is simply based on the inter-beat-interval series obtained from PPG, and that uses features of heart rate variability. The candidate algorithm was tested against gold standard scoring of whole night state-of-theart sleep studies. The PPG-based sleep scoring performs very well in differentiating sleep stages, however, the sleep/wake separation is not sufficient and requires improvement. This last task is facilitated by the fact that the majority of devices with PPG capabilities, are equipped with accelerometers providing additional information for better separation. Combining accelerometers and PPG signals from wearable devices in a sleep analyser is likely to provide a reliable and accurate automated detection of sleep and wakefulness, including sleep macro-and microarchitecture.

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Mobile Based Study Links Insomnia and Sympathovagal Balance

2016 Computing in Cardiology Conference (CinC), 2016

Insomnia is a high prevalence sleep disorder. Current theories point towards the role of cognitiv... more Insomnia is a high prevalence sleep disorder. Current theories point towards the role of cognitive and physiological hyperarousal in the pathophysiology of Insomnia. Our aim was to investigate the potential application of autonomic nervous system viewed through the prism of heart rate variability for understanding and assessing insomnia. Inter beat intervals were recorded using a mobile app, SleepRate, and an off-the-shelf sport belt. 98 users who participated in a sleep assessment and therapy program were labeled by the app as insomniacs (IN). They were compared to 250 users who just monitored their sleep. Heart-rate variability analysis was performed for each night. Mean heart-rate in IN was significantly higher than in reference group (RG). Sympathovagal balance values for each of the different sleep stages and for the period prior to sleep onset were significantly higher in IN compared to the RG. Mobile technology enabled very large scale, measurement of physiological signals. The findings indicate an increased sympathetic predominance in IN. This is consistent with recent theories linking physiological hyperarousal and insomnia. The autonomic approach to sleep evaluation may be a useful alternative to the gold standard whole-night PSG for poor sleepers.

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Stress indices in methadone maintenance treatment - Cross sectional and follow up study

Psychiatry Research

1010 Sleep Related Recovery in Athletes: The Role of Heart Rate Variability Parameters

Sleep

Impact of Digital Monitoring, Assessment and Cognitive Behavioral Therapy on Subjective Sleep Quality, Workplace Productivity and Health Related Quality of Life: Observational Study (Preprint)

BACKGROUND Sleep difficulties negatively impact health, performance and quality of life, as about... more BACKGROUND Sleep difficulties negatively impact health, performance and quality of life, as about a third of the general population suffers from at least one insomnia symptom. Recent studies link insomnia with reduced work productivity, resulting in extensive losses for employees, employers and insurers. Cognitive behavioral therapy for insomnia (CBTi) is recommended as first-line treatment for insomnia and the ubiquity of smart mobile devices allows for promising approaches to overcome some of the limitations surrounding it. OBJECTIVE Our aim was to propose a comprehensive sleep solution for smart mobile devices, and to characterize the effects of this solution, while using adequate sample sizes. METHODS Employees of a Fortune-50 company were randomly selected, all with a Pittsburgh Sleep Quality Index (PSQI) larger than 8. Subjects were randomly assigned to either an intervention group (IG, n=247) or a control group (CG, n=249), and were asked to fill several questionnaires, in ad...

[Sleep of Elite Young Athlete at the Academy for Sport Excellence at the Wingate Institute]

Harefuah, Jun 1, 2016

Sleep duration and quality have a critical role in cognitive and athletic performances. A relatio... more Sleep duration and quality have a critical role in cognitive and athletic performances. A relationship was demonstrated between sleep deprivation, reduced performance and elevated injury risk. The recommended sleep duration for teenagers is at least 9 hours a day but most sleep less. To estimate sleep duration among elite adolescent athletes at the Academy for Sport Excellence at the Wingate Institute, by quantifying the changes after joining the academy and the relation to school performances and the usage of medical services. Data from medical records, including sleep screening questionnaires and a number of the athletes' medical appointments were analyzed. Athletes reported that sleep duration was less than recommended before joining the academy. After joining the academy the average sleep duration decreased (7.37 vs 7.7 hours, P = 0.05) and daytime sleepiness was elevated (13/24 v 11/24 Epworth-Sleepiness-Scale (ESS), P = 0.002). Correlations between changes in sleep duratio...

Mobile Health Sleep Technologies

Telehealth and Mobile Health, 2015

Sleep in the cloud: On how to use available heart rate monitors to track sleep and improve quality of life

by Shuli Eyal and Anda Baharav

Home monitoring for infants at high risk for the sudden infant death syndrome

Israel journal of medical sciences, 1997

The rate of sudden infant death syndrome (SIDS) In Israel is relatively low (0.5-0.9:1,000). Home... more The rate of sudden infant death syndrome (SIDS) In Israel is relatively low (0.5-0.9:1,000). Home cardiorespiratory monitoring (HM) is an accepted practice in infants at high risk for SIDS. We report our experience with 261 infants who were referred to our SIDS prevention program. They included: 52 preterm infants with apneas and bradycardias, 83 SIDS siblings (3 twins), 22 infants of drug-addicted mothers, and 104 infants after an idiopathic apparent life-threatening event (ALTE). HM was performed in 40 of 52 preterms, 38 of 83 SIDS siblings, all 22 infants of addicted mothers and 67 of 104 post-ALTE. All received 24 h/day medical and technical backup as well as emotional support, and were closely followed until 15 months of age. None of the 261 infants died. Five infants experienced six ALTEs that required resuscitative measures; another 28 infants had monitor alarms judged as real by the caregivers. The average duration of HM was 3.2 months (range 1-7). In 8 of 167 cases the pare...

Electrocardiogram derived respiration during sleep

by Zvi Shinar and Anda Baharav

Computers in Cardiology, 2005, 2005

The aim of this study was quantify the ECG Derived Respiration (EDR) in order to extend the capab... more

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Validation of ECG-derived sleep architecture and ventilation in sleep apnea and chronic fatigue syndrome

by Zvi Shinar and Anda Baharav

Sleep and Breathing, 2010

Purpose Newly developed algorithms putatively derive measures of sleep, wakefulness, and respirat... more Purpose Newly developed algorithms putatively derive measures of sleep, wakefulness, and respiratory disturbance index (RDI) through detailed analysis of heart rate variability (HRV). Here, we establish levels of agreement for one such algorithm through comparative analysis of HRV-derived values of sleep-wake architecture and RDI with those calculated from manually scored polysomnographic (PSG) recordings. Methods Archived PSG data collected from 234 subjects who participated in a 3-day, 2-night study characterizing polysomnographic traits of chronic fatigue syndrome were scored manually. The electrocardiogram and pulse oximetry channels were scored separately with a novel scoring algorithm to derive values for wakefulness, sleep architecture, and RDI. Results Four hundred fifty-four whole-night PSG recordings were acquired, of which, 410 were technically acceptable. Comparative analyses demonstrated no difference for total minutes of sleep, wake, NREM, REM, nor sleep efficiency generated through manual scoring with those derived through HRV analyses. When NREM sleep was further partitioned into slow-wave sleep (stages 3-4) and light sleep (stages 1-2), values calculated through manual scoring differed significantly from those derived through HRV analyses. Levels of agreement between RDIs derived through the two methods revealed an R=0.89. The Bland-Altman approach for determining levels of agreement between RDIs generated through manual scoring with those derived through HRV analysis revealed a mean difference of −0.7±8.8 (mean±two standard deviations). Conclusion We found no difference between values of wakefulness, sleep, NREM, REM sleep, and RDI calculated from manually scored PSG recordings with those derived through analyses of HRV.

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Cluster headache patients have normal circadian and sleep time autonomic nervous system function

by Zvi Shinar and Anda Baharav

Computers in Cardiology, 2005, 2005

Cluster headache (CH) is a rare form of primary headache of neurovascular origin causing severe p... more

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