- American society of anesthesiologist class (ASA) I & II (ASA I: normal healthy patient; ASA II: patient with mild systemic disease; no functional limitation)；Preoperative MRI diagnosis of supratentorial lesions (glioma, meningioma or neurofibroma), and tumor diameter <= 40 mm；The subject gets full score for Glasgow Coma Score；Estimated operation time <= 6 hours and anesthesia time <= 8 hours；The subject has given written informed consent.