Braindex Cerebral Tissue Oxygen Saturation (SctO2) Measurement Algorithm Assessment and Improvement

A continuous measurement of VjO2S, the usual reference measurement of the marketed devices, will be performed by implanting an optical fiber (CEVOX, PULSION Medical Systems) through an internal jugular catheter in addition to the classical catheter of the external electro-systolic drive probe. The following parameters will be recorded every 2 seconds: invasive blood pressure (systolic, mean and diastolic), heart rate, SaO2 on the pulse wave. VjO2S will be recorded continuously during the entire implantation procedure. The time of the beginning of the surgical incision, of the beginning of sinus tachycardia (overdriving) induced by external electro-systolic stimulation, of the beginning of inflation of the intravalvular aortic balloon, of the maximum occlusion of the balloon, of the end of complete deflation of the balloon, of the end of stimulation and of the end of skin closure will be recorded.