Table 1.

Six frequency intervals and the physiological origins.

Frequency Interval (Hz)		Physiological Origins
I	0.6–2	cardiac activity
II	0.145–0.6	respiratory activity
III	0.052–0.145	myogenic activity
IV	0.021–0.052	neurogenic activity
V	0.0095–0.021	NO-related endothelial activity
VI	0.005–0.0095	endothelial activity