Validation of an existing algorithm designed to estimate blood pressure based on collected optical signals on patients against two reference methods, which are the arterial catheter (arm 1) and the ausculatory sphygmomanometer (arm 2).

The purpose of the study is to compare the blood pressure values measured by a mobile application used with a smartphone and the values measured by reference equipments, which are the arterial line and the ausculatory sphygmomanometer .

In the arm 1 of the study, patients scheduled for general anesthesia at the Centre Hospitalier Universitaire Vaudois (CHUV) and at the Hôpitaux Universitaire de Genève (HUG) will be recruited and their pressure will be measured with both mesurement methods. General anesthesia is known to generate significant variations in blood pressure at the time of induction. During the first minutes of anesthesia, the patient's blood pressure will be measured in parallel with the mobile application and with the reference equipment. After the intervention, the values obtained by the two methods will be compared to confirm the reliability of the data obtained with the mobile application.

In the arm 2, patients scheduled for a medical appointment at the hypertension unit of the Centre Hospitalier Universitaire Vaudois (CHUV) will be recruited. Their pressure will be measured with the mobile application and with the reference equipment at various time points. After the intervention, the values obtained by the two methods will be compared to confirm the reliability of the data obtained with the mobile application.

In the arm 3, patients scheduled for a medical appointment at the maternity unit of the Centre Hospitalier Universitaire Vaudois (CHUV) will be recruited. Their pressure will be measured with the mobile application and with the reference equipment at various time points. After the intervention, the values obtained by the two methods will be compared to confirm the reliability of the data obtained with the mobile application.

Arm 1, Inclusion Criteria:

• Informed Consent as documented by signature
• Men or women older than 18 years old
• Good understanding of written and oral speaking used at the centre where the study will be carried out
• American Society of Anesthesiology clinical classification Risk (ASA) Class 1-3
• Scheduled for a general anesthesia
• Necessitating an arterial catheters for the anesthesia and surgery.

Arm 1, Exclusion Criteria:

• Patients that cannot sign informed consent
• Patients in emergency situation, are not legally competent, cannot understand the situation
• ASA Risk class 4
• Dyshythmia like bigeminy, trigeminy, isolated Ventricular Premature Beats (VPB), atrial fibrillation
• Lesion or deficiency on hand, preventing index obstruction of smartphone's camera
• Known contact dermatitis to nickel/chromium

Arm 2, Inclusion Criteria:

• Informed Consent as documented by signature
• Men or women older than 18 years old
• Good understanding of written and oral speaking used at the centre where the study will be carried out

Arm 2,Exclusion Criteria:

• Patients that cannot sign informed consent
• Patients in emergency situation, are not legally competent, cannot understand the situation
• Known or suspected non-compliance (e.g. drug or alcohol abuse, language problems, psychological disorders, dementia)
• Known pregnancy
• Systolic blood pressure difference between two arms >15mmHg or, diastolic blood pressure difference between two arms >10mmHg
• Unstable cardiac condition (myocardial infarction < 1 week, pulmonary embolism, ventricular arrhythmia, decompensated heart failure)
• Dysrhythmia like bigeminy, trigeminy, isolated Ventricular Premature Beats (VPB), atrial fibrillation
• Lesion or deficiency on hand, preventing index obstruction of smartphone's camera
• Known contact dermatitis to nickel/chromium.

Arm 3, Inclusion Criteria:

• Informed Consent as documented by signature
• Pregnant women older than 18 years old
• Good understanding of written and oral speaking used at the centre where the study will be carried out
• Scheduled for a prepartum anesthesia consultation at the hospital maternity unit

Arm 3,Exclusion Criteria:

• Patients that cannot sign informed consent
• Patients in emergency situation, are not legally competent, cannot understand the situation
• Known or suspected non-compliance (e.g. drug or alcohol abuse, language problems, psychological disorders, dementia)
• Systolic blood pressure difference between two arms >15mmHg or, diastolic blood pressure difference between two arms >10mmHg
• Unstable cardiac condition (myocardial infarction < 1 week, pulmonary embolism, ventricular arrhythmia, decompensated heart failure)
• Dysrhythmia like bigeminy, trigeminy, isolated Ventricular Premature Beats (VPB), atrial fibrillation
• Lesion or deficiency on hand, preventing index obstruction of smartphone's camera
• Known contact dermatitis to nickel/chromium.

Only pregnant women are eligible to take part in the study arm 3. No gender-based eligibility criteria exist for the recruitment of patients in the first and seconf arm of the study.