Description
Respiration monitoring estimates breathing rate (and sometimes depth) from periodic chest-wall motion that modulates a CSI stream. Phase-based and csi-ratio-based features dominate because the millimetre-scale chest displacement is below the resolution of amplitude-only systems. It is the canonical "fine-grained" test for any new CSI representation — if you cannot recover a 0.1–0.5 Hz periodicity in the chest signal, the representation is too coarse.
When it's used
- Sleep / overnight monitoring
- In-home health-tracking deployments
- Driver monitoring in vehicle-cabin sensing
- Sensitivity benchmark for new CSI feature pipelines
Limitations
- Single-person assumption breaks when multiple people share the link
- Sensitive to body orientation and link geometry
- Requires several seconds of stationary observation