| RMSSD, SDNN, pNN50 | Time-domain HRV | FLIRT + DBDP HRV calculator | Autonomic dysregulation tracking. Drops in HRV correlate with vasomotor severity and sleep disruption. |
| HF / LF power, LF:HF ratio | Frequency-domain HRV | FLIRT | Sympathetic vs parasympathetic balance. Useful in stratifying patients for HRT vs non-hormonal pathways. |
| Non-linear: SD1, SD2, CSI, CVI | Poincaré + chaotic HRV | FLIRT | Sensitive to overall autonomic load. Early indicator for cardiovascular risk shifts post-menopause. |
| Sleep fragmentation, IBI entropy | Statistical HRV | FLIRT | Direct proxy for night sweats and disrupted sleep — the #1 patient-reported symptom in our research. |
| EDA tonic / phasic decomposition | Electrodermal activity | FLIRT (Empatica E4, Phase 2) | Hot-flash detection from skin conductance peaks. |
| Activity counts, sedentary bouts | Accelerometer | FLIRT | Fatigue and activity regression — a quality-of-life signal payers care about. |