Wearable Alignment-Free Microfiber-Based Sensor Chip for Precise Vital Signs Monitoring and Cardiovascular Assessment

Continuous pulse wave signals monitoring is the essential basis for clinical cardiovascular diagnosis and treatment. Recent researches show the majority of current electronic pulse sensors usually face challenges in electrical safety concern, poor durability and demanding precision in position alignment. Thus, a highly sensitive, inherently electrical safe, robust and alignment-free device is highly desired. Here, we present a wearable alignment-free microfiber-based sensor chip (AFMSC) for precise vital signs monitoring and cardiovascular health assessment. The AFMSC comprises an optical micro/nano fiber sensor (MNF) and a flexible soft liquid sac while the MNF sensor is used to perceive the physiological signals and the liquid sac is used to eliminate the misalignment. The real-time and accurate monitoring of the pulse signals was realized by tracking the optical power variation of transmitted light from MNF. Then, the cardiovascular vital signs extracted from radial artery pulse signals were used to evaluate cardiovascular health condition and the results were in accordance with human physiological characteristics. Moreover, the pulse signals from different arterial area, the respiration signals from chest and the radial pulse signals before and after exercise were detected and analyzed. The non-invasive, continuous and accurate monitoring of cardiovascular health based on the reported wearable and alignment-free device is promising in both fitness monitoring and medical diagnostics for cardiovascular disease prevention and diagnosis.