User Perceptions and Experiences of a Handheld 12-Lead Electrocardiographic Device in a Clinical Setting: Usability Evaluation - Kam Cheong Wong; Aravinda Thiagalingam; Saurabh Kumar; Simone Marschner; Ritu Kunwar; Jannine Bailey; Cindy Kok; Tim Usherwood; Clara K Chow (JMIR Cardio, 2021)