According to an analysis by the U.S Food and Drug Administration (FDA), the Cerebrospinal Fluid shunt valve, which is magnetic externally programmable, has a setting that can change from a distance less than 2 inches to any magnetic sources that are common these days including cell phones.

The direct effect on the valve setting, due to the influence of the magnetic sources, is seen as a potential threat to the patients who have implanted valve settings. Certain unintended changes are seen in patients with implanted magnet-influenced devices, which can be due to exposure to the strong magnetic fields sources around, such as cochlear implants.