A Wearable Dynamic Foot Pressure Measurement System
Diabetic Foot Ulcer (DFU) is a complication of diabetes; this causes impaired mobility and even death. Higher
rate of DFU occurrence adds huge burden on the healthcare system and billions are spent healing the wound. There is a need
for reliably measuring dynamic foot pressure so that the users who are at a risk of DFU can be given feedback in real time to
help them avoid DFU. We are developing a dynamic foot pressure measurement system in house to provide full coverage of
risk foot areas and can measure up to 100 channels of dynamic pressure. In this paper we present a miniature 12 channel
dynamic foot pressure measurement system consisting of an analog front end, an MCU based data acquisition module and a
sensorized sock. This system can measure, analyze and store dynamic foot pressure data and feedback to the user in real time
through on board aural and visual indicators. It can also optionally push the collected data to the back end server through a
wireless link. Sensorized sock was fabricated by embedding off the shelf Force Sensitive Resistor (FSR) elements on the
sock and wired up using conductive threads to form an array. Non-Inverting Op-Amp Circuit on board analog front end
converts the resistance variations of the pressure sensor into a voltage which is then converted to digital using an on chip
ADC of the MCU. MCU further analyzes the data and activates alarms when the detected pressure values exceed preset
threshold values. The pressure measurement range of this system is 100– 600Kpa with targeted accuracy of +/-2% and the
scanning rate is 10 fps.
Keywords - Diabetic Foot Ulcer, Dynamic Foot Pressure, Sensorized Sock, Force Sensitive Resistor (FSR), Op-Amp.