Fiber-based quantum-dot pulse oximetry for wearable health monitoring with high wavelength selectivity and photoplethysmogram sensitivity

Increasing demand for real-time healthcare monitoring is leading to advances in thin and flexible optoelectronic device-based wearable pulse oximetry. Most previous studies have used OLEDs for this purpose, but did not consider the side effects of broad full-width half-maximum (FWHM) characteristics and single substrates. In this study, we performed SpO(2) measurement using a fiber-based quantum-dot pulse oximetry (FQPO) system capable of mass production with a transferable encapsulation technique, and a narrow FWHM of about 30 nm. Based on analyses we determined that uniform angular narrow FWHM-based light sources are important for accurate SpO(2) measurements through multi-layer structures and human skin tissues. The FQPO was shown to have improved photoplethysmogram (PPG) signal sensitivity with no waveguide-mode noise signal, as is typically generated when using a single substrate (30-50%). We successfully demonstrate improved SpO(2) measurement accuracy as well as all-in-one clothing-type pulse oximetry with FQPO.

Automated summary

The increasing demand for real-time healthcare monitoring is driving the development of thin and flexible optoelectronic wearable pulse oximetry devices. Previous studies using OLEDs did not consider the side effects of broad FWHM characteristics and single substrates. This study introduces a fiber-based quantum-dot pulse oximetry system with a narrow FWHM of about 30nm, which enables accurate SpO2 measurements through multi-layer structures and human skin tissues. The FQPO showed improved photoplethysmogram signal sensitivity without waveguide-mode noise signal, offering potential for all-in-one clothing-type pulse oximetry.