Graphical layouts, algorithms, and methods are introduced herein to implement user interfaces for mobile and/or wearable medical devices. In one aspect of the present invention, new graphical layouts are introduced for simplified presentation of time-dependent patient data. In another aspect of the invention, methods and algorithms are introduced to acquire, extract and present relevant features of patient data in real-time in order to simplify the graphical presentation and interpretation. In another aspect of the invention, elements of a multi-modal user interface are introduced in order to simplify and minimize the users interaction with the medical wearable device. In yet another aspect of the invention, further methods are introduced for real-time interaction between a user or several users and a wearable or several wearable medical devices. In one embodiment of the present invention, a smartphone, a smart watch, a head-mounted device or similar devices can be used to acquire and display in real-time patient data, e.g., electrocardiogram and relevant features, e.g., heart rate, etc. In another embodiment of the present invention, smartphones, smart watches, head-mounted devices or similar devices can be used to share in real-time the patient data.