In a March 2024 study by Tomoya Nakazawa of Hamamatsu Photonics (Japan) on near-infrared light (NIR) to estimate blood glucose levels, said
“[The] phase delay-based metabolic index, which has not been reported by other researchers, is a scientifically important discovery,”
“The proposed method can in principle be implemented in existing smart devices with a pulse oximetry function and is inexpensive, battery-saving, and simple compared with other noninvasive blood glucose monitoring techniques. Thus, our approach could be a powerful tool towards portable and accessible BGL monitoring devices in the future.”