Towards the Development of an Alternating Pressure Overlay for the Treatment of Pressure Ulcers Using Miniaturised 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 duration. This research aims to design miniaturised air bladders which could provide alternating pressure sequences for the treatment of the pressure ulcers. The optimally designed 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 air bladders are analysed using the finite element method. Based on the interface pressure the pressure overlay has been divided into five pressure zones. 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 electropneumatic valves operated based on the back pressure 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.