Portable Ultrasound-Based Device for Detecting Older Adults' Sit-to-Stand Transitions in Unsupervised 30-Second Chair-Stand Tests. - Antonio Cobo; Elena Villalba Mora; Dieter Hayn; Xavier Ferré Grau; Rodrigo Pérez-Rodríguez; Alberto Sánchez-Sánchez; Raquel Bernabé-Espiga; Juan-Luis Sánchez-Sánchez; Andrea López-Diez-Picazo; Cristian Moral; Leocadio Rodríguez-Mañas (Sensors, 2020)