Fig. 2

Evolution of ultrasound scanners. 1st generation: cumbersome, mainly available in dedicated hospital rooms with highly trained operators. 2nd generation: more accessible laptop-based ultrasound solutions, architecture like the first one, where the electronics in a trolley has been replaced with a more portable like laptop platform; expanded adoption to different clinical fields. 3rd generation: integration with mobile, app-based (ultra-)portable ultrasound devices, the probe of the previous generation equipment and part of electronics (up to the beamformer) are generally included in a single object (smart handheld probes); some of the functions previously implemented in the electronics (i.e., the scan converter) are now implemented by a software application that runs in a separated device; more affordable and accessible. 4th generation: concept of wearable device, where all the functions of the smart probe should be implemented in single system; theoretically accessible to everyone