Researchers have designed a sensor necklace that records the date and time a pill is swallowed, which they hope will increase drug compliance and decrease unnecessary health care costs. The device could be used to ensure that the elderly and subjects in clinical drug trials take their medications as directed by a physician. The necklace, called MagneTrace, contains an array of magnetic sensors that could be used to detect when specially-designed medication containing a tiny magnet passes through a person’s esophagus. And for persons who may not want to wear a necklace, MagneTrace sensors can be incorporated into a patch attached to the chest.