According to some embodiments, the force generated by the noninvasively adjustable implantable medical device and / or the non-invasively change in the dimensions of the non-invasively adjustable implantable medical device is detected noninvasively A system and method are provided. Some of the systems include a non-invasively adjustable implant including a driven magnet and an external adjustment device including one or more drive magnets and one or more Hall effect sensors. The Hall effect sensor of the external adjustment device is configured to detect a change in the magnetic field between the driven magnet of the non-invasively adjustable implant and the drive magnet (s) of the external adjustment device. The change in magnetic field can be used to calculate the force generated by the noninvasively adjustable implantable medical device and / or the change in its size.(FIG.
