Kobashi Ruka, Anabuki Daichi, Yano Hibiki, Mukaihara Yuto, Nishiyama Akira, Wada Kenji, Nishimura Akiko, Ishimaru Ichiro
Graduate School of Science for Creative Emergence, Kagawa University, 2217-20 Hayashi-cho, Takamatsu 761-0396, Kagawa, Japan.
Faculty of Medicine, Kagawa University, 1750-1 Miki-cho, Kita 761-0793, Kagawa, Japan.
Sensors (Basel). 2025 Jul 22;25(15):4537. doi: 10.3390/s25154537.
Mid-infrared passive spectroscopic imaging is a novel non-invasive and remote sensing method based on Planck's law. It enables the acquisition of component-specific information from the human body by measuring naturally emitted thermal radiation in the mid-infrared region. Unlike active methods that require an external light source, our passive approach harnesses the body's own emission, thereby enabling safe, long-term monitoring. In this study, we successfully demonstrated the simultaneous, non-invasive measurements of blood glucose and lactate levels of the human body using this method. The measurements, conducted over approximately 80 min, provided emittance data derived from mid-infrared passive spectroscopy that showed a temporal correlation with values obtained using conventional blood collection sensors. Furthermore, to evaluate localized metabolic changes, we performed k-means clustering analysis of the spectral data obtained from the upper arm. This enabled visualization of time-dependent lactate responses with spatial resolution. These results demonstrate the feasibility of multi-component monitoring without physical contact or biological sampling. The proposed technique holds promise for translation to medical diagnostics, continuous health monitoring, and sports medicine, in addition to facilitating the development of next-generation healthcare technologies.
中红外被动光谱成像技术是一种基于普朗克定律的新型非侵入式遥感方法。它通过测量人体在中红外区域自然发射的热辐射，获取人体特定成分的信息。与需要外部光源的主动方法不同，我们的被动方法利用人体自身的辐射，从而实现安全、长期的监测。在本研究中，我们成功地使用该方法同时对人体血糖和乳酸水平进行了非侵入式测量。测量持续约80分钟，提供了源自中红外被动光谱的发射率数据，这些数据与使用传统采血传感器获得的值呈现出时间相关性。此外，为了评估局部代谢变化，我们对上臂获得的光谱数据进行了k均值聚类分析。这使得能够以空间分辨率可视化随时间变化的乳酸反应。这些结果证明了无需物理接触或生物采样即可进行多成分监测的可行性。除了促进下一代医疗技术的发展外，所提出的技术在医学诊断、连续健康监测和运动医学领域具有应用前景。
