This observational study will collect synchronized photoplethysmography (PPG) and electrocardiogram (ECG) recordings from approximately 50 healthy adult volunteers. Participants will wear the Corsano CardioWatch 297-2 and a reference ECG device simultaneously for approximately 24 hours, including standardized activities and free-lining conditions. The objective is to generate a high-quality paired ECG-PPG dataset to support the development and evaluation of artificial intelligence methods fro reconstructing ECG parameters, with a particular focus on QT/QTc, from PPG signals. The study will also evaluate the feasibility and usability of the wearable monitoring system.