Reflection-Boosted Wearable Ring-Type Pulse Oximeters for SpO2 Measurement with High Sensitivity and Low Power Consumption

In this study, we demonstrated a Monte Carlo simulation to model finger structure and calculate the intensity of photons passing through tissues, in order determine optimal angular separation between photodetector (PD) light-emitting diode (LED), detect SpO2. Furthermore, our was used suggest mirror-coated ring-type pulse oximeter improve sensitivity by up 80% power consumption 65% compared mirror-uncoated structure. A (RPO) is widely photoplethysmography (PPG) signals for SpO2 measurement during sleep health-status monitoring. Device an RPO, which are key performance indicators, vary greatly with geometrical arrangement PD LED within inner surface RPO. We propose reflection-boosted design RPO achieve both high low consumption, configuration performing 3D confirming its agreement experimental measurement. confirm terms signal-to-noise ratio, R perfusion index (PI), RPOs were fabricated without highly reflective coating, then from eight participants. Our allows numerical calculation photon scattering tissues. The enables reliable sensitivity, resulting less longer device usage than conventional any maintain same level SNR PI. Compared non-reflective reference enhanced detected light (67% dc 322% ac at wavelength λ1 = 660 nm, also 81% 375% λ2 940 respectively) PI (23.3% 25.5% λ2). Thus, not only reliability but significantly improved i.e., requiring 36% 30% drive sources λ2, respectively, produce reference. It expected that proposed provides long-term monitoring capability