Collection of Synchronised ECG and PPG Recordings in Healthy Adult Volunteers to Develop and Evaluate AI Methods for ECG- Parameter Reconstruction From PPG (Focus: QT/QTc).

Inclusion Criteria

Inclusion Criteria: * Able to provide written informed consent. * Willing and able to comply with all study procedures and attend the required study visits. * Age ≥18 years. * Able to read or understand Dutch or English. Exclusion Criteria: * Children/minors or vulnerable individuals. * Skin conditions or allergies preventing safe wear of the CardioWatch or ECG electrodes. * Any condition that, in the investigator's opinion, may interfere with study completion or data quality. * Compromised circulation, injury, or physical malformation at sensor sites. * Known clotting disorders or current prescription anticoagulant therapy. * Other health conditions preventing safe participation. * Wrist circumference \<14 cm or \>23 cm. * Any participant who, in the investigator's opinion, does not meet study requirements