Disease introduction: Acute kidney injury (AKI) is the main complication and cause of death after cardiopulmonary bypass (CPB). Since its pathogenesis has not been fully elucidated, it poses great difficulties for early prevention and treatment.

　　Experimental animals: SD rats (6-8 weeks)

　　Experimental methods: 1. Skin preparation and disinfection, the right external jugular vein and right internal carotid artery were exposed through a longitudinal incision in the neck, and the right femoral artery was exposed through a right inguinal incision. The pressure sensor measures blood pressure, and the right external jugular vein central venous catheter establishes venous access. 2. Connect the extracorporeal circulation pipeline. After the extracorporeal circulation starts, gradually increase the perfusion flow according to the drainage volume and the liquid level of the blood storage chamber, and suture the surgical incision. 3. Monitoring circulation effect through blood pressure and heart rate.