Treatment Duration on Normobaric Hyperoxia in Acute Ischemic Stroke

Scores assessed by National Institutes of Health Stroke Scale(NIHSS)

secondary clinical efficacy endpoint; the NIHSS is a stroke severity score composed of 11 items (range from 0 to 41, higher values indicate more severe deficits)

Time frame: 24hours, 72hours, day7 after randomization

The proportion of good prognosis

the mRs is an ordinal disability score of 7 categories (0 = no symptoms to 5 = severe disability, and 6 = death;with higher scores indicating more severe disability);The ratio of 0 to 2;

Time frame: 90 ± 10 days after randomization

neurological function improvement rate

NIHSS score increased by more than 4 points);the NIHSS is a stroke severity score composed of 11 items (range from 0 to 42, higher values indicate more severe deficits);

Time frame: Time Frame: 24 ± 6 hours

modified Rankin Scale score (mRS) score

secondary clinical efficacy endpoint; the mRs is an ordinal disability score of 7 categories (0=no symptoms to 5=severe disability,and 6=death)

Time frame: 30 ± 7 days, 90 ± 10 days after randomization;

Vascular recanalization rate

secondary imaging efficacy endpoint; Extended Treatment In Cerebral Ischemia (eTICI)；The eTICI is an ordinal hierarchical scale ranging from 0 to 3, with higher scores indicating better antegrade reperfusion of the previously occluded target artery ischemic territory; eTICI 2B or 3 are defined as successful recanalization;

Time frame: Time Frame: 4 hours ± 15 minutes

blood biomarkers : occludin(ng/ml), MMP-9(ng/ml), S100B(ng/ml),NSE(ng/ml),GFAP(ng/ml),PGP9.5(ng/ml),etc

Biomarkers for evaluation of BBB damage , brain injury and inflammation,etc:

Time frame: 24 ± 6 hours, 72 ± 24 hours

Incidence of oxygen-related adverse events

Including Headache, dizziness, nausea, vomiting, chest tightness, shortness of breath, cough,etc;

Time frame: 24 ± 6 hours,

Incidence of neurologic deterioration;

NIHSS score increased by more than 4 points);the NIHSS is a stroke severity score composed of 11 items (range from 0 to 42, higher values indicate more severe deficits);clinical safety endpoint;

Time frame: 24 ± 6 hours;

Incidence of Symptomatic Intracerebral Hemorrhage

imaging safety endpoints;Deterioration in NIHSS score of ≥4 points within 24 hours;per ECASS III definition and per Heidelberg bleeding classification

Time frame: 24± 12 hours hours after randomization

Incidence of any intracranial hemorrhage

imaging safety endpoints;per ECASS III definition and per Heidelberg bleeding classification

Time frame: 24± 12 hours hours after randomization

all-cause death rate

clinical safety endpoint; Ratio of total deaths from all causes to all enrollments

Time frame: 90 ± 10 days after randomization

Incidence of adverse events

clinical safety endpoint;

Time frame: 90 ± 10 days after randomization

Incidence of surgery-related complications

clinical safety endpoint;

Time frame: 24± 12 hours hours after randomization

stroke related death rate

clinical safety endpoint; Stroke-related deaths as a proportion of all participants

Time frame: 90 ± 10 days after randomization;

Vital signs:respiration(times/min)

clinical safety endpoint;

Time frame: 0 hours, 2 hours, 4 hours after randomization;

Vital signs:heart rate: (times/min)

clinical safety endpoint;

Time frame: 0 hours, 2 hours, 4 hours after randomization;

Vital signs:blood pressure(mmHg)

clinical safety endpoint;

Time frame: 0 hours, 2 hours, 4 hours after randomization;

Vital signs:oxygen saturation (%)

clinical safety endpoint;

Time frame: 0 hours, 2 hours, 4 hours after randomization;