In Bed Contactless Cardiorespiratory Signals Monitoring Using Optical Fiber Interferometry

Monitoring of cardiac and respiratory activity results crucial in clinical settings. However, specific, expensive and usually wired devices are required, which results in cumbersome configurations. Therefore, there is a large research interest in the development of noninvasive monitoring systems. Some authors have proposed the use of fiber-optic speckle interferometry, enabling for contact-less patient monitoring. In this study, we exploited this technology, and explored the performance of different fiber-optic configurations, in combination with robust signal processing algorithms, for heart and respiratory rates estimation. Several configurations were tested, all of them resulting in very low estimation errors. A qualitative analysis revealed that our system can be suited to track fast changes in respiration, as well as the presence of apneas. Such a system might be useful for noninvasive patient monitoring, specially in overnight recordings (e.g., OSAS or AF) or specific scenarios, such as magnetic resonances.