Impact of optical wavelength on the reliability of photoplethysmography-based heart rate measurements outside of controlled laboratory environments

作者：Manuel Meier, Christian Holz · 发表于：Current Issues in Sport Science (CISS) · 年份：2024 · DOI：10.36950/2024.2ciss060 · 被引用次数：3

Introduction The effectiveness of heart rate (HR) measurements via photoplethysmography (PPG) depends on the wavelength of light used. Typical PPG sensors use green, red, or infrared light, each penetrating the skin to different depths (Ray et al., 2021). Here, we present a comparative analysis of the reliability of HR measurements using these wavelengths. Methods Our study collected a dataset of 16 participants, each wearing four PPG sensing devices placed at the forehead, sternum, ankle (supramalleolar), and wrist. Each device continuously recorded reflective PPG signals, whereas the device at the sternum additionally captured the Lead I ECG for reference. During the 13 hours of capture, participants went on an outdoor trip from downtown Zurich to the Jungfraujoch railway station at 3,460 m above sea level in the mountains. PPG measurements were obtained using a state-of-the-art MAX86141 optical analog front-end (AFE) coupled with an illumination module of red, green, and infrared LEDs (SFH7072), along with two photodiodes. The ECG recording was resolved by a biopotential AFE (MAX30003), affixed on the chest with gel electrodes. All devices were synchronized by aligning recorded signals post-hoc (33ms accuracy, Meier & Holz, 2023). The HR was extracted from the ECG via time-domain peak detection and a quotient filter. HR was separately derived from each PPG signal, both by time-domain peak detection and frequency-domain analysis. The HR was computed every 5 seconds for a...