He ended up inventing a device that he's calling the "Safe Wander," which is a small, lightweight pressure-sensitive button that attaches to the bottom of a patient's sock. Anytime pressure is applied, an alert is sent to a caretaker's smartphone. By putting these socks on his grandfather before bedtime every night, he was able to successfully detect 437 cases of wandering in a six-month span with no false alarms.
Kenneth Shinozuka: My simple invention, designed to keep my grandfather safe
Teen Invents Sensor to Help Alzheimers Patients - NBC News.com