Two systems operating at two different frequencies,provide audio blood flow detection at different depth of penetration.
Mizuho 8 MHz Surgical Doppler System - 2 cm depth penetration depending on th density of surrounding tissue and bone along with variety of disposable probes is beneficial for location of carotid artery in transsphenoidal surgery or evaluate anastomosis or bypass surgery and so on.
Mizuho 20 MHz Surgical Doppler System - A high frequence implement a focused signal with a shallow depth(1cm) of penetration along with disposable probes is beneficial for assessment of aneurism clip placement or occlusion and so on.