Subhagata Chattopadhyay^1,, Rupam Das¹

Background: Heart Rate Variability (HRV) surrogates for Cardiac Autonomic Modulation (CAM), while Pulse Rate variability (PRV) reflects Cardiovascular Autonomic Modulation (CvAM). HRV and PRV therefore, are not exactly interchangeable terms. However, the paper proposes that PRV and HRV can be correlated. Aim: To compare the correlation between two different instruments – (I) gold-standard Polar H10 HRV sensor that works on the principle of CAM and Kubios software for HRV estimation, together called ‘PK’ and (II) Lyfas smartphone application called ‘L’, which estimates PRV that reflects the state of CvAM. Methods: Parameters, such as (i) HR, (ii) RMSSD, (iii) pNN50, (iv) SDNN, and (v) LF/HF are captured from a total of 567 healthy Indian adults (312 males and 255 females) using PK and L simultaneously. End HR data (120 sec) are then compared instrument and gender-wise statistically by computing the i) RMSE, ii) Regressions (L on PK), iii) a Two-sample t-test, and (iv) classification accuracy of L when compared to PK. Finally, the Sensitivity/recall (R), Specificity (S), Precision (P), Accuracy (A), F score (F), and Youden’s index (Y) are computed for L. Results: L shows encouraging averages for males and females respectively ‘R’ (84%, 70%), ‘S’ (95%, 87%), ‘A’ (82%, 79%), ‘P’ (87%, 69%),’F’ (1.4836, 1.3706) and ‘Y’ (79%, 81%) for HR, SDNN, RMSSD, and pNN50 respectively. Conclusions: Although ‘L’ has 1/33th times less resolution compared to PK, its technical efficacy, speed, user-friendliness, low-cost-benefit, high ‘Y’ values, and ubiquitousness pose a great advantage in its deployment in the clinical setup as a biomarker tool over PK.

Heart Rate Variability, Pulse Rate variability, Polar H10 HRV sensor, Kubios software, Lyfas, Youden’s index, Biomarker, Biofeedback