Flexible Sensor Suite Integrated Into Textile for Calcium Ion and Fall Detection

Studies show that excessive loss of sweat calcium is associated with the deterioration of bone mineral density in young athletes during vigorous intensity exercise. Low levels of bone mineral density cause a higher risk of bone fracture, meaning that a single fall can be devastating. This letter reports a smart compression sock that detects calcium levels in sweat and simultaneously scans for a fall and alerts the user accordingly. The sock is washable, and the device is removable using a Velcro pad attached to the inner side of the sock. An electrochemical sensor detects the calcium levels, while a triaxial accelerometer detects a fall event. When paired with a fall detection algorithm, the accelerometer quickly determines if a fall has occurred based on the differential acceleration. The calcium and fall detection units are interfaced with a microcontroller that sends the information to a user interface platform via the Blynk Internet of Things cloud. If the calcium level is above/below the critical value or a fall is detected, a notification along with the user's GPS location is sent to authorized emergency contacts so that the user can be attended to immediately. In addition, the electronic components were soldered onto a flexible printed circuit board. Such an integrated flexible system will allow the continuous monitoring of athletes to drive just-in-time intervention.