Evaluation of Free-Living Motor Symptoms in Patients With Parkinson Disease Through Smartwatches: Protocol for Defining Digital Biomarkers - Polvorinos-Fernandez, Carlos; Sigcha, Luis; Centeno-Cerrato, Maria; de Arcas, Guillermo; Grande, Miriam; Marin, Mayca; Parees, Isabel; Martinez-Castrillo, Juan Carlos; Pavon, Ignacio (Jmir Research Protocols, 2025)