title: Comparison of Heart-Rate-Variability Recording With Smartphone Photoplethysmography, Polar H7 Chest Strap, and Electrocardiography.
abstract: OBJECTIVE
  To establish the validity of smartphone photoplethysmography (PPG) and heart-rate sensor in the measurement of heart-rate variability (HRV).
  
  
  METHODS
  29 healthy subjects were measured at rest during 5 min of guided breathing and normal breathing using smartphone PPG, a heart-rate chest strap, and electrocardiography (ECG). The root mean sum of the squared differences between R-R intervals (rMSSD) was determined from each device.
  
  
  RESULTS
  Compared to ECG, the technical error of estimate (TEE) was acceptable for all conditions (average TEE CV% [90% CI] = 6.35 [5.13; 8.5]). When assessed as a standardized difference, all differences were deemed "trivial" (average standard difference [90% CI] = 0.10 [0.08; 0.13]). Both PPG- and heart-rate-sensor-derived measures had almost perfect correlations with ECG (R = 1.00 [0.99; 1.00]).
  
  
  CONCLUSIONS
  Both PPG and heart-rate sensors provide an acceptable agreement for the measurement of rMSSD when compared with ECG. Smartphone PPG technology may be a preferred method of HRV data collection for athletes due to its practicality and ease of use in the field.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Plews
authors.forename: Ben
authors.initials: B
authors.lastname: Scott
authors.forename: Marco
authors.initials: M
authors.lastname: Altini
authors.forename: Matt
authors.initials: M
authors.lastname: Wood
authors.forename: Andrew E
authors.initials: AE
authors.lastname: Kilding
authors.forename: Paul B
authors.initials: PB
authors.lastname: Laursen
mesh_terms: D000328:Adult; D056352:Athletes; D004562:Electrocardiography; D005260:Female; D064368:Healthy Volunteers; D006339:Heart Rate; D006801:Humans; D008297:Male; D017156:Photoplethysmography; D000068997:Smartphone; D055815:Young Adult
keywords: athletic performance; cardiac parasympathetic; monitoring