scholarly journals Measuring Heart Rate Variability in Free-Living Conditions Using Consumer-Grade Photoplethysmography: Validation Study

10.2196/17355 ◽  
2020 ◽  
Vol 5 (1) ◽  
pp. e17355
Author(s):  
Emily Lam ◽  
Shahrose Aratia ◽  
Julian Wang ◽  
James Tung

Background Heart rate variability (HRV) is used to assess cardiac health and autonomic nervous system capabilities. With the growing popularity of commercially available wearable technologies, the opportunity to unobtrusively measure HRV via photoplethysmography (PPG) is an attractive alternative to electrocardiogram (ECG), which serves as the gold standard. PPG measures blood flow within the vasculature using color intensity. However, PPG does not directly measure HRV; it measures pulse rate variability (PRV). Previous studies comparing consumer-grade PRV with HRV have demonstrated mixed results in short durations of activity under controlled conditions. Further research is required to determine the efficacy of PRV to estimate HRV under free-living conditions. Objective This study aims to compare PRV estimates obtained from a consumer-grade PPG sensor with HRV measurements from a portable ECG during unsupervised free-living conditions, including sleep, and examine factors influencing estimation, including measurement conditions and simple editing methods to limit motion artifacts. Methods A total of 10 healthy adults were recruited. Data from a Microsoft Band 2 and a Shimmer3 ECG unit were recorded simultaneously using a smartphone. Participants wore the devices for >90 min during typical day-to-day activities and while sleeping. After filtering, ECG data were processed using a combination of discrete wavelet transforms and peak-finding methods to identify R-R intervals. P-P intervals were edited for deletion using methods based on outlier detection and by removing sections affected by motion artifacts. Common HRV metrics were compared, including mean N-N, SD of N-N intervals, percentage of subsequent differences >50 ms (pNN50), root mean square of successive differences, low-frequency power (LF), and high-frequency power. Validity was assessed using root mean square error (RMSE) and Pearson correlation coefficient (R2). Results Data sets for 10 days and 9 corresponding nights were acquired. The mean RMSE was 182 ms (SD 48) during the day and 158 ms (SD 67) at night. R2 ranged from 0.00 to 0.66, with 2 of 19 (2 nights) trials considered moderate, 7 of 19 (2 days, 5 nights) fair, and 10 of 19 (8 days, 2 nights) poor. Deleting sections thought to be affected by motion artifacts had a minimal impact on the accuracy of PRV measures. Significant HRV and PRV differences were found for LF during the day and R-R, SDNN, pNN50, and LF at night. For 8 of the 9 matched day and night data sets, R2 values were higher at night (P=.08). P-P intervals were less sensitive to rapid R-R interval changes. Conclusions Owing to overall poor concurrent validity and inconsistency among participant data, PRV was found to be a poor surrogate for HRV under free-living conditions. These findings suggest that free-living HRV measurements would benefit from examining alternate sensing methods, such as multiwavelength PPG and wearable ECG.

2019 ◽  
Author(s):  
Emily Lam ◽  
Shahrose Aratia ◽  
Julian Wang ◽  
James Tung

BACKGROUND Heart rate variability (HRV) is used to assess cardiac health and autonomic nervous system capabilities. With the growing popularity of commercially available wearable technologies, the opportunity to unobtrusively measure HRV via photoplethysmography (PPG) is an attractive alternative to electrocardiogram (ECG), which serves as the gold standard. PPG measures blood flow within the vasculature using color intensity. However, PPG does not directly measure HRV; it measures pulse rate variability (PRV). Previous studies comparing consumer-grade PRV with HRV have demonstrated mixed results in short durations of activity under controlled conditions. Further research is required to determine the efficacy of PRV to estimate HRV under free-living conditions. OBJECTIVE This study aims to compare PRV estimates obtained from a consumer-grade PPG sensor with HRV measurements from a portable ECG during unsupervised free-living conditions, including sleep, and examine factors influencing estimation, including measurement conditions and simple editing methods to limit motion artifacts. METHODS A total of 10 healthy adults were recruited. Data from a Microsoft Band 2 and a Shimmer3 ECG unit were recorded simultaneously using a smartphone. Participants wore the devices for &gt;90 min during typical day-to-day activities and while sleeping. After filtering, ECG data were processed using a combination of discrete wavelet transforms and peak-finding methods to identify R-R intervals. P-P intervals were edited for deletion using methods based on outlier detection and by removing sections affected by motion artifacts. Common HRV metrics were compared, including mean N-N, SD of N-N intervals, percentage of subsequent differences &gt;50 ms (pNN50), root mean square of successive differences, low-frequency power (LF), and high-frequency power. Validity was assessed using root mean square error (RMSE) and Pearson correlation coefficient (<i>R</i><sup>2</sup>). RESULTS Data sets for 10 days and 9 corresponding nights were acquired. The mean RMSE was 182 ms (SD 48) during the day and 158 ms (SD 67) at night. <i>R</i><sup>2</sup> ranged from 0.00 to 0.66, with 2 of 19 (2 nights) trials considered moderate, 7 of 19 (2 days, 5 nights) fair, and 10 of 19 (8 days, 2 nights) poor. Deleting sections thought to be affected by motion artifacts had a minimal impact on the accuracy of PRV measures. Significant HRV and PRV differences were found for LF during the day and R-R, SDNN, pNN50, and LF at night. For 8 of the 9 matched day and night data sets, <i>R</i><sup>2</sup> values were higher at night (<i>P=</i>.08). P-P intervals were less sensitive to rapid R-R interval changes. CONCLUSIONS Owing to overall poor concurrent validity and inconsistency among participant data, PRV was found to be a poor surrogate for HRV under free-living conditions. These findings suggest that free-living HRV measurements would benefit from examining alternate sensing methods, such as multiwavelength PPG and wearable ECG.


2011 ◽  
Vol 10 (1) ◽  
pp. 27 ◽  
Author(s):  
Jesper Kristiansen ◽  
Mette Korshøj ◽  
Jørgen H Skotte ◽  
Tobias Jespersen ◽  
Karen Søgaard ◽  
...  

1997 ◽  
Vol 78 (5) ◽  
pp. 709-722 ◽  
Author(s):  
Beatrice Morio ◽  
Patrick Ritz ◽  
Elisabeth Verdier ◽  
Christophe Montaurier ◽  
Bernard Beaufrere ◽  
...  

The aim of the present study was to validate against the doubly-labelled water (DLW) technique the factorial method and the heart rate (HR) recording method for determining daily energy expenditure (DEE) of elderly people in free-living conditions. The two methods were first calibrated and validated in twelve healthy subjects (six males and six females; 70·1 (sd 2·7) years) from opencircuit whole-body indirect calorimetry measurements during three consecutive days and during 1 d respectively. Mean energy costs of the various usual activities were determined for each subject using the factorial method, and individual relationships were set up between HR and energy expenditure for the HR recording method. In free-living conditions, DEE was determined over the same period of time by the DLW, the factorial and the HR recording methods during 17, 14 and 4 d respectively. Mean free-living DEE values for men estimated using the DLW, the factorial and the HR recording methods were 12·8 (sd 3·1), 12·7 (sd 2·2) and 13·5 (sd 2·7) MJ/d respectively. Mean free-living DEE values for women were 9·6 (sd 0·8), 8·8 (sd 1·2) and 10·2 (sd 1·5) MJ/d respectively. No significant differences were found between the three methods for either sex, using the Bland & Altman (1986) test. Mean differences in DEE of men were -0·9 (sd 11·8) % between the factorial and DLW methods, and +4·7 (sd 16·1) % between the HR recording and DLW methods. Similarly, in women, mean differences were -7·7 (sd 12·7) % between the factorial and DLW methods, and +5·9 (sd 8·8) % between the HR recording and DLW methods. It was concluded that the factorial and the HR recording methods are satisfactory alternatives to the DLW method when considering the mean DEE of a group of subjects. Furthermore, mean energy costs of activities calculated in the present study using the factorial method were shown to be suitable for determining free-living DEE of elderly people when the reference value (i.e. sleeping metabolic rate) is accurately measured.


Animals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1867
Author(s):  
Michele Panzera ◽  
Daniela Alberghina ◽  
Alessandra Statelli

Background: Few studies have been performed to identify objective indicators for the selection of therapeutic donkeys or to assess their welfare during animal-assisted interventions (AAIs) Objective: This study aimed to evaluate the response to the ethological test and the modifications of physiological parameters in donkeys subjected to AAI sessions. Methods: Thirteen donkeys were subjected to a behavioral evaluation during an AAI session. Heart rate, heart rate variability, and root mean square of successive difference values were detected. Results: Statistically significant changes in the tested parameters were observed during AAI sessions. Conclusions: In donkeys, there was a neurovegetative involvement during AAI sessions. Our data give a contribution to the evaluation of donkey welfare during AAIs.


2017 ◽  
Vol 5 (10) ◽  
pp. e157 ◽  
Author(s):  
Alexander Wilhelm Gorny ◽  
Seaw Jia Liew ◽  
Chuen Seng Tan ◽  
Falk Müller-Riemenschneider

Hypertension ◽  
2020 ◽  
Vol 76 (4) ◽  
pp. 1256-1262
Author(s):  
Balewgizie S. Tegegne ◽  
Tengfei Man ◽  
Arie M. van Roon ◽  
Nigus G. Asefa ◽  
Harriëtte Riese ◽  
...  

Dysregulation of the cardiac autonomic nervous system, as indexed by reduced heart rate variability (HRV), has been associated with the development of high blood pressure (BP). However, the underlying pathological mechanisms are not yet fully understood. This study aimed to estimate heritability of HRV and BP and to determine their genetic overlap. We used baseline data of the 3-generation Lifelines population-based cohort study (n=149 067; mean age, 44.5). In-house software was used to calculate root mean square of successive differences and SD of normal-to-normal intervals as indices of HRV based on 10-second resting ECGs. BP was recorded with an automatic BP monitor. We estimated heritabilities and genetic correlations with variance components methods in ASReml software. We additionally estimated genetic correlations with bivariate linkage disequilibrium score regression using publicly available genome-wide association study data. The heritability (SE) estimates were 15.6% (0.90%) for SD of normal-to-normal intervals and 17.9% (0.90%) for root mean square of successive differences. For BP measures, they ranged from 24.4% (0.90%) for pulse pressure to 30.3% (0.90%) for diastolic BP. Significant negative genetic correlations (all P <0.0001) of root mean square of successive differences/SD of normal-to-normal intervals with systolic BP (−0.20/−0.16) and with diastolic BP (−0.15/−0.13) were observed. LD score regression showed largely consistent genetic correlation estimates of root mean square of successive differences/SD of normal-to-normal intervals with systolic BP (range, −0.08 to −0.23) and diastolic BP (range, −0.20 to −0.27). Our study shows a substantial contribution of genetic factors in explaining the variance of HRV and BP measures in the general population. The significant negative genetic correlations between HRV and BP indicate that genetic pathways for HRV and BP partially overlap.


Stroke ◽  
2021 ◽  
Author(s):  
Galit Weinstein ◽  
Kendra Davis-Plourde ◽  
Alexa S. Beiser ◽  
Sudha Seshadri

Background and Purpose: The autonomic nervous system has been implicated in stroke and dementia pathophysiology. High resting heart rate and low heart rate variability indicate the effect of autonomic imbalance on the heart. We examined the associations of resting heart rate and heart rate variability with incident stroke and dementia in a community-based cohort of middle- and old-aged adults. Methods: The study sample included 1581 participants aged >60 years and 3271 participants aged >45 years evaluated for incident dementia and stroke, respectively, who participated in the Framingham Offspring cohort third (1983–1987) examination and had follow-up for neurology events after the seventh (1998–2001) examination. Heart rate variability was assessed through the standard deviation (SD) of normal-to-normal RR intervals and the root mean square of successive differences between normal heartbeats from 2-hour Holter monitor. Participants were followed-up for stroke and dementia incidence from exam 7 to a maximum of 10 years. Cox regression models were used to assess the link of resting heart rate and heart rate variability with stroke and dementia risk while adjusting for potential confounders, and interactions with age and sex were assessed. Results: Of the dementia (mean age, 55±6 years, 46% men) and stroke (mean age, 48±9 years, 46% men) samples, 133 and 127 developed dementia and stroke, respectively, during the follow-up. Overall, autonomic imbalance was not associated with dementia risk. However, age modified the associations such that SD of normal-to-normal intervals and root mean square of successive differences were associated with dementia risk in older people (hazard ratio [HR] [95% CI] per 1SD, 0.61 [0.38–0.99] and HR [95% CI] per 1SD, 0.34 [0.15–0.74], respectively). High resting heart rate was associated with increased stroke risk (HR [95% CI] per 10 bpm, 1.18 [1.01–1.39]), and high SD of normal-to-normal intervals was associated with lower stroke risk in men (HR [95% CI] per 1SD, 0.46 [0.26–0.79]) but not women (HR [95% CI] per 1SD, 1.25 [0.88–1.79]; P for interaction=0.003). Conclusions: Some measures of cardiac autonomic imbalance may precede dementia and stroke occurrence, particularly in older ages and men, respectively.


2016 ◽  
Vol 48 ◽  
pp. 786-787 ◽  
Author(s):  
Jung-Min M. Lee ◽  
Hyunsung An ◽  
Seoung-ki Kang ◽  
Youngdeok Kim ◽  
Danae Dinkel

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