The patent mentions the requirement of a sensor which can range from sensors such as gyroscopes already installed in most smartphones these days. Accelerometers are one of them, and more advanced sensors such as GPS and imaging sensors can be used to help detect when a fall is taking place. It has also been suggested that statistics from falls, such as height, time to impact, and speed of the fall can be stored in the phone, allowing the system to compute the best solution in the event you drop your phone.
As for shifting the center of mass for the phone, the patent did list a couple of different ways it could go about doing that. One of the examples was to use a weighted mass, lift foils that extend from the device, or even some sort of thrust mechanism where a small can of gas can be fired off inside the device, although it sounds that this method might actually end up doing more damage instead! Then again, this is only a patent which means we may never see it come to fruition, but we admit it’s a pretty good idea nonetheless.