An in vivo device (1) for an at least temporary placement in a human or animal body (17), comprising an actuator (2) adapted to be actively triggered from the exterior in order to induce a local impact on the adjacent body area for in vivo treatment of a patient in need, and/or comprising a sensor adapted to be actively triggered from the exterior for sensing a pathological condition in the body (17). An in vivo system comprises at least two and/or a plurality of the in vivo devices (1), wherein the in vivo devices (1) are adapted to communicate with each other and/or with an external controller (24). The use of the in vivo device/s (1) for treating and/or diagnosing a pathological condition in a human or animal body (17) comprises: administering the device/s (1)； monitoring the movement of the device/s (1) through the body (17)； triggering the device/s (1) from the outside once the device/s (1) reach/es a defined position in the body (17).
