Very Short-Term Photoplethysmography-Based Heart Rate Variability for Continuous Autoregulation Assessment

Abstract

Background: Heart rate variability (HRV) has been widely applied for disease diagnosis. However, the 5 min signal length for HRV analysis is needed. Method: A signal processing procedure for very short-term photoplethysmography (PPG) signal for fever detection and autoregulation assessment was proposed. The Time-Shift Multiscale Entropy Analysis (TSME) was applied to instantaneous pulse rate time series (iPR) and normalized by the cumulative distribution function (CDF) of all scales to calculate novel indices. A total of 33 subjects were recruited for the study. Fifteen participants whose body temperatures were higher than 37.9 °C were served as the fever group. Others were served as the non-fever group. The total 15 s PPG signal with 200 sampling rates was used for iPR calculation. Result: The CDF value of entropy on the scale k = 19 (CDF(E(k = 19))) of iPR had the lowest p-value calculated by the Weltch t-test between two groups (p < 0.001). The Spearman correlation r between CDF(E(k = 19)) and body temperature is −0.757, 0.287, and −0.830 in all subjects, the non-fever group and the Fever group, respectively. The area under the curve, calculated from the receiver operating characteristic of CDF(E(k = 19)) of iPR is 0.915. Conclusion: The entropy of iPR is useful for detecting fever. Moreover, a short-term PPG signal is suitable to develop real-time applications, and multiscale entropy provides different scales of information for daily healthcare.

Two Sides of the Same Virtual Coin: Investigating Psychosocial Effects of Video Game Play, Including Stress Relief Motivations as a Gateway to Problematic Video Game Usage

“…This was chosen based on accessibility and convenience as the author did not have access to Electrocardiogram (ECG) equipment that produces the signal necessary to measure HRV. It is acknowledged that whilst the signal used during IPR measurement "exists between ECG and PPG signals" (Huang & Hsiao, 2022; pg. 2), it is not the most ideal proxy for measuring heart rate.…”

Two Sides of the Same Virtual Coin: Investigating Psychosocial Effects of Video Game Play, including Stress Relief Motivations as a Gateway to Problematic Video Game Usage

“…This was chosen based on accessibility and convenience as the author did not have access to electrocardiogram (ECG) equipment that produces the signal necessary to measure HRV. It is acknowledged that whilst the signal used during IPR measurement "exists between ECG and PPG signals" [81], it is not the most ideal proxy for measuring heart rate. Using a measure such as instantaneous pulse rate variability [82,83] may have been a better alternative considering the resources available.…”