The validity and reliability of an open source biosensing board to quantify heart rate variability

Abstract

Background: Heart rate variability (HRV) is a popular tool to quantify autonomic function. However, this typically requires an expensive 3-12 lead electrocardiogram (ECG) and BioAmp system. This investigation sought to determine the validity and reliability of an OpenBCI cyton biosensing board (open source) for accurately quantifying HRV. New method: A cyton board with a 3-lead ECG was employed to acquire heart rate waveform data, which was processed to obtain HRV within both time-and frequency-domains. The concurrent validity was compared to a simultaneous recording from an industry-standard 3-lead ECG (ADInstruments) (n ¼ 15). The reliability of the cyton board was compared between three days within a 7-day timespan (n ¼ 10). Upright quiet-stance short-term HRV metrics were quantified in time-and frequency-domains. Results: The two devices displayed excellent limits of agreements (all log mean differences AE0.4) and very high between-device variable associations (all r 2 > 0.98). Between the three time points in the same subjects, no differences were noted within time-(all p > 0.71) or frequency-domains (all p > 0.88) across testing points. Finally, all HRV metrics exhibited excellent levels of reliability through high Cronbach's Alpha (all !0.916) and intraclass correlation coefficients (all !0.930); and small standard error of the measurement (all 0.7) and typical error of the measurement (all 0.1) metrics.Comparison with existing methods: The cyton board with 3-lead ECG was compared with an industry-standard ADInstruments ECG during HRV assessments. There were no significant differences between devices with respect to time-and frequency-domains. The cyton board displayed high-levels of between-day reliability and provided values harmonious to previous ECG literature highlighting the applicability for longitudinal studies. Conclusion: With proper background knowledge regarding ECG principles and a small degree of set-up complexity, an open source cyton board can be created and employed to perform multimodal HRV assessments at a fraction of the cost (~4%) of an industry-standard ECG setup.

The influence of external stressors on physiological testing: Implication for return-to-play protocols

“…Although measures of ANS function, such as HRV, exhibit a degree of day-to-day variation, this variability is not statistically significant if multiple recordings are collected under similar conditions ( Burma et al, 2021 ). For example, ANS activity fluctuates throughout the day as rhythmic circadian changes modulate endogenous physiological mechanisms ( Smolensky et al, 2017 ).…”

Validity and reliability of short‐term heart‐rate variability from disposable electrocardiography leads

“…Over the past two decades, several investigations have scrutinized the validity and reliability of commercially available technologies for the assessment of HRV. 20 , 21 , 22 , 23 , 24 However, these devices are mainly designed for fitness/athletic purposes and may have little use in clinical settings. This is the first study to provide evidence on the performance accuracy of the novel; disposable ECG leads to evaluate HRV, which is a highly sensitive physiological measure used in a clinical setting for risk stratification and monitoring purposes.…”

“…Evidence from available literature assessing multiple technologies suggests large discrepancies in the design and analytical methods used to analyze time and frequency domain variables leading to conflicting results and difficulty in making comparisons among studies. For example, some studies 20 , 25 , 26 analyzed HRV data using independent commercially available software to interpret R‐R interval data, rather than the specific analytical tools designed, and recommended by the device hardware provider. Our study is unique as HRV data are collected using disposable and reusable ECG leads but data were analyzed using the same analytical methods.…”

“… 30 Our results show a similar trend for method agreement and reliability with other studies for time‐domain HRV measures derived from short‐term recordings. 20 , 26 It was previously recommended to use higher sampling frequencies, usually from 500 Hz, for HRV evaluations. 15 However, such high frequency is often impractical in clinical settings due to technological limitations of certain medical devices (e.g., Holter monitors), which are compact with small battery capacities, thus limiting sampling frequencies to around 125 Hz.…”

“…Over the past two decades, several investigations have scrutinized the validity and reliability of commercially available technologies for the assessment of HRV 20–24 . However, these devices are mainly designed for fitness/athletic purposes and may have little use in clinical settings.…”