There are multiple definitions:

1. warping index(English)

   • ECG, FCI
   • Signal analysis

2. water immersion(English)

   • applied to evaluate cardiovascular and autonomic responses to physiological stressors in humans
   • CVR, DBP, HR, HRV, HUT, LF/HF, SBP, SV, SVR
   • Nervous activity - (para)sympathetic, Stress (test)
   • https://doi.org…siol.00466.2013

3. written information(English)

   • FPPE, PVS, RDoC
   • Communication, Emotional aspects
   • https://doi.org…rat.2023.104384