: Patient readmission to PICU is a major point of concern for physicians because, although being a rare event, it has been strongly associated with more morbidity and death. Patient monitoring once they have left the PICU is drastically modified, and small connected devices could be an option to early identify patients at risk of PICU readmission. Such devices have been manufactured for the recording of vital signs in adults, but they do not exist for children.

Besides, studies have recently shown that devices that use optical sensors may be less accurate in individuals with dark skin pigmentation since dark skin tones impose a limitation on optical biometric sensing. The wearable and medical device industry has not sufficiently addressed this issue yet. This is one of the main challenges that need to be addressed in this area to make sure the connected devices using this technology will work with all different skin colours including very dark skin.

Main objective: Assess the accuracy of VT-Patch® to measure oxygen saturation (SpO2) in children with diverse skin colour.

Secondary objectives: Assess the accuracy of VT-Patch® to measure 3 additional physiologic parameters (heart rate (HR), respiratory rate (RR), and temperature. Exploratory assessment of blood pressure (BP) measurement, ECG signal, and movement capture.

Design: Prospective validation study of VT-Patch® for the recording of 4 physiologic parameters and exploratory assessment of three additional parameters.

Methods: The study will be performed in two successive phases:

Run-in phase: Testing VT-Patch® on four children to assess the feasibility of the protocol.

Main study: validation phase of the devices on 12 children per age group (2 children per skin colour group) to assess its accuracy (VT-Patch® for less than 2 years old). The patients of the run-in phase will be included in the main study if no modification of the protocol is required. 5 physiologic parameters (HR, SpO2, RR, temperature, and ECG) will be prospectively and simultaneously recorded for 8 hours with VT-Patch® and the regular monitoring system implemented in the unit High-resolution database that will be the gold standard for evaluation. Vital signs recorded with the connected device will not be used for the clinical care of patients. The Skin colour of each patient will be assessed by the colorimetric Monk scale and as shown below.

Inclusion Criteria:

• PICU monitoring for the next 24 hours

Exclusion Criteria:

• Recent cardiac or thoracic surgery
• Thoracic skin lesion that contraindicates the VT patch
• No parental consent
• Intermittent presence of one study observer in the patient room considered inappropriate by the physician or the nurse in charge because of the child's medical condition

In order to achieve at least 80% match between physiological data's recorded with VT-Patch®, or VT-Watch® and with the standard of care (tolerated difference: 2% for SpO2), this study will include 10 patients per age group (see below) including 4 patients per age group with invasive arterial pressure monitoring (arterial line).

1. Neonates: 0 - 28 days
2. Infants:29 days - 2 years
3. Children: 2 - 12 years
4. Adolescents:12 - 18 years