A non-intrusive mattress based on an optical-fiber Michelson interferometer is designed for daily sleep monitoring. The optical phase signal of the optical-fiber Michelson interferometer caused by the heartbeat and respiration is demodulated by the phase-generated carrier (PGC) method. The physiological signals and vital indicators including heart rate (HR), respiration rate (RR), and signal energy (SE) are extracted from the optical phase by algorithmic processing. A series of experiments are conducted to confirm the feasibility of the mattress for sleep monitoring. The mattress not only can achieve HR and RR counting, but also can record the waveform of the sleep-induced signal accurately. The body states can also be distinguished by the SE. In an all-night sleep monitoring experiment, the HR measured by the mattress is compared with the HR measured by a commercial smart band, showing a maximum error of 6 bpm (beat per minute). The designed mattress based on an optical-fiber Michelson interferometer shows good performance and great potential in non-intrusive sleep monitoring.

Salinity extremes (SEs) play a crucial role in marine ecosystems, ocean circulation, and climate variability. Understanding their distribution and drivers is essential for predicting changes in ocean salinity under climate change, particularly in dynamic regions such as the Hawaiian Islands, where mesoscale eddies significantly modulate water mass properties. This study investigates the three-dimensional characteristics of SEs and their responses to mesoscale eddies using mooring observations and sea surface salinity data. We find that high salinity extremes (HSEs) generally occur more frequently than low salinity extremes (LSEs) in the study region, though LSEs exhibit greater duration and intensity. Mesoscale eddies modulate SEs significantly—anticyclonic eddies (AEs) enhance LSEs, whereas cyclonic eddies (CEs) promote HSEs in the upper layer. This relationship reverses in the deeper layer, with AEs favoring HSEs and CEs enhancing LSEs. These opposing effects are driven by a vertical displacement of the subsurface salinity maximum layer, where CEs lift high-salinity subsurface water to the upper ocean via upwelling, creating HSEs in the upper layer and LSEs in the deeper layer, while AEs subduct high-salinity water downward, reducing upper-layer salinity (LSEs) but increasing deeper-layer salinity (HSEs) via downwelling. Spatially, CEs exhibit a single-core high-salinity anomaly, displaced westward by 0.3 times of the eddy radius from the eddy center, with HSEs peaking in frequency and intensity near the core. In contrast, AEs display a dipole salinity anomaly (low northwest/high southeast), aligning with LSE frequency distribution, while HSEs show an inverse pattern. Mooring data further reveal that AE-LSE co-occurrence is highest within 1.2 times of the eddy radius, whereas CE-HSE probability declines with eddy intensity. Notably, AE-HSE and CE-LSE probabilities, though initially weaker, surpass AE-LSE and CE-HSE at certain depths, underlining the complexity of depth-dependent eddy modulation. These findings may advance understanding of ocean salinity dynamics and provide insights into how mesoscale processes modulate extreme events, with implications for marine biogeochemistry and climate modeling.