Table 1. Phase classification of hemodynamic responses.

Phase	Description	Relationships between the 4 indicators
Phase 1	Hyperoxia/Hyperemia	0 < ΔD < ΔO, ΔCOE < 0 < ΔCBV
Phase 2	Hypoxia/Hyperemia	0 < ΔO < ΔD, 0 < ΔCOE < ΔCBV
Phase 3	Hypoxia/Hyperemia	ΔO < 0 < ΔD, 0 < ΔCBV < ΔCOE
Phase 4	Hypoxia/Ischemia	ΔO < 0 < ΔD, ΔCBV < 0 < ΔCOE
Phase 5	Hypoxia/Ischemia	ΔO < ΔD < 0, ΔCBV < 0 < ΔCOE
Phase -1	Hyperoxia/Hyperemia	ΔD < 0 < ΔO, ΔCOE < 0 < ΔCBV
Phase -2	Hyperoxia/Ischemia	ΔD < 0 < ΔO, ΔCOE < ΔCBV < 0
Phase -3	Hyperoxia/Ischemia	ΔD < ΔO < 0, ΔCBV < ΔCOE < 0