Foot Pressure-Sensor System for Tracking Safety and Health

Abstract

This paper presents an innovative pressure sensor systemembedded in a sock, which has a number of health care applications. One of these is the low-cost, reliable detection of the bed-departure of Alzheimer’s patients, an increasingly common problem that causes significant stress to caregivers. The system comprises a pressure sensor embedded in a sock and a coin battery-powered microcontroller containing a radiofrequency module. Once the user wanders out of bed and steps onto the floor, the sensor on the sock will immediately detect the pressure caused by his or her body weight and will wirelessly trigger an audible sound in a caregiver’s monitoring unit, which can be a Smartphone, tablet, or dedicated monitor. Furthermore, the pressure sensor and the microcontroller can be combined into one re-attachable unit, which can be stuck conveniently to the ball or heel of the user’s foot or any ordinary sock, slipper or shoe. In addition, the system can function as a highly accurate pedometer that is useful for monitoring the user’s health by tracking changes in his or her gait characteristics. In this study, a prototype sensor sock was developed that included an ultra-thin flexible pressure sensor, microcontroller, Bluetooth low energy module, and control software. The efficacy of the sensor sock in detecting and alerting patients’ wandering has been demonstrated.