Towards the Development of an Alternating Pressure Overlay for the Treatment of Pressure Ulcers Using Miniaturized Air Cells

This paper presents a study on design and development of an alternating pressure overlay consists of inflatable mini air-bladders, which could be used in relieving and reducing tissue pressure for the treatment of pressure ulcers. Pressure ulcers, which are predominant in the bony prominences of the body, is a skin deformity due to the limitation of blood circulation to the muscle tissues as a result of high pressures applied on the skin for longer durations. This research aims to design miniaturized air bladders which could provide alternating pressure sequences for the treatment of the pressure ulcers. The optimally designed geometries of mini air-bladders provide proper envelopment of the patient’s body and create a high resolution of pressure distribution. The optimum geometry and the 3-D deformation profile of the mini air-bladders are analyzed using the finite element method. Furthermore, the real-time interface pressure profile between the body and the overlay is mapped by using the back pressure of mini air-bladders. The actuator system includes an integrated control unit that regulates the internal pressures via electro-pneumatic valves operated based on the backpressure sensor feedback. This actuator system provides the alternating pressure patterns required for inflation and deflation of the mini air-bladders controlling the airflow of the support surface, providing proper pressure distributions to heal the ulcers.