Helical long period fiber grating sensor for non-invasive measurement of vital signs

Long-term monitoring of the heartbeat and respiration of patients is critical for adjusting their care. However, current approaches are limited by skin contact, which may cause discomfort and restrict patients' physical ac-tivities. In this study, we propose a new device for the non-invasive monitoring of vital signs based on a helical long-period grating (HLPG) sensor. The HLPG was fabricated with a single-mode fiber using a CO2 laser. The mode coupling in HLPG was analyzed and high curvature sensitivity (20.16 nm/m- 1) was obtained, indicating its potential for monitoring vital signs. The experimental results of four healthy subjects indicated that the sensing system could simultaneously monitor vital signs. In conclusion, our sensing system is a promising candidate for long-term monitoring in hospital settings and healthcare.

Automated summary

Long-term monitoring of patients' heartbeat and respiration is crucial for adjusting their care, but current methods are limited by skin contact, causing discomfort and restricting physical activities. This study proposes a new non-invasive monitoring device using a helical long-period grating (HLPG) sensor. The HLPG, fabricated with a single-mode fiber using a CO2 laser, demonstrates high curvature sensitivity (20.16 nm/m-1) for vital sign monitoring. Experimental results on four healthy subjects show that the sensing system can simultaneously monitor vital signs. In conclusion, this sensing system holds promise for long-term monitoring in hospital settings and healthcare.