Raspberry Pi-based Decubitus Reducing Mattress with Air Pressure Monitoring System and Air Leaks Detector

Decubitus ulcers appear when the skin receives intense pressure for a short time or mild pressure for a longer time. Currently, nurses assist immobilized patients to change their position every 2 hours to avoid decubitus ulcers. Another option is using the pressure-reducing mattress. This mattress has the feature to change the pressure strength, but the air pressure and leakage are unknown. Both of these problems will be overcome by the automatic mattress developed in this study. The developed mattress uses gas pressure sensors, a Raspberry Pi, solenoid valves, and an AC air pump. The mattress pumping process is controlled based on the air pressure from 0.7 to 2.1 PSI in 3.5 minutes for each airbag group. The airbags are controlled to form wavelike contours with the feedback from the gas pressure sensors. A prolonged period to reach maximum pressure indicates the air leaks. The testing result shows that the control system can maintain the pressure of the airbag from 0.7 to 2.1 PSI accurately during the pumping process, with or without load on the mat. The accuracy of the pumping duration for each airbag group is 96.31% from the 3.5 minutes goal and gives no meaningful effect to skin pressure.