The main objective of this study is to show the concordance of the SctO2 values of the ARGOS platform with the standard SctO2 values (comparative study with platform INVOS, Medtronic).

SctO2 values from ARGOS and INVOS will be resampled every 30 seconds. The two signals will then be resynchronized and compared on a sample-by-sample basis using a Pearson correlation test. Bias and agreement limits will be assessed using Bland & Altmann graphs. This test will be carried out for the entire duration of the recording.

Inclusion Criteria:

• Patient, male or female, over 18 years of age
• Patient scheduled for cardiac surgery with programmed extracorporeal circulation (ECC)
• Patient with no history of scalp injury or or skin diseases
• Patient with an Euroscore 2 of less than 7%.
• Patient affiliated or entitled to a social assurance

Exclusion Criteria:

• Weight under 40 kg
• Frontal surface too small to allow application of SctO2, BIS electrodes on the same hemifront
• Patient with severe, unbalanced hypertension
• Measurement of systolic blood pressure (SBP) > 180 mm Hg and/or diastolic blood pressure (DBP) > 110 mm Hg
• Patients undergoing emergency surgery
• Patient with chronic renal failure, with glomerular filtration < 30 ml/min/1.73m², or requiring renal transplantation or requiring renal transplantation
• Patient with left ventricular ejection fraction < 40%
• Patient with a history of ischemic stroke
• Patients with preoperative sepsis
• Patient requiring noradrenaline infusion noradrenaline infusion in the 24 hours prior to surgery
• Patient with preoperative uni or bilateral carotid stenosis bilateral carotid stenosis > 50%.
• Protected patient: adult under guardianship, curatorship or legal protection, deprived of liberty by judicial or administrative decision.
• Pregnant, parturient or breast-feeding women.
• Patients hospitalized without consent.