Automated Seat Cushion for Pressure Ulcer Prevention Using Real-Time Mapping, Offloading, and Redistribution of Interface Pressure
Abstract
The act of sitting in a wheelchair can have significant implications for individuals with limited mobility such as those with spinal cord injuries (SCI). Mechanical loading forces cause compression and shearing in tissues near bony regions such as the tailbone and sit bones; if these loading forces are not relieved, blood flow is dramatically reduced and tissues begin to die as a result of inadequate oxygenation. These lesions -- known as pressure ulcers (PUs) -- can result in full thickness tissue loss, bone infection, or sepsis. Once PUs form, they are notoriously difficult, costly, and time-consuming to treat; a serious PU requires months of treatment and costs can range from $400,000 - $700,000. Even with rigorous care guidelines, 85% of SCI individuals will develop a PU in their lifetime, and ~8% will die from related complications. Adequate pressure relief is a necessity. The proposed work aims to develop a smart seat cushion technology that will enable real-time pressure monitoring and automated pressure modulation capabilities to help combat the formation of PUs in the highly susceptible SCI population. The proposed smart seat cushion consists of a sensorized bubble actuator (air cell) array and control hardware that allows real-time pressure mapping and control of individual air cells for localized pressure modulation. A graphical user interface (GUI) displays the real-time pressure profile and enables the user or caregiver to selectively offload pressure at sensitive areas; the system will then redistribute the pressure to other areas based on the current pressure profile while keeping shear forces below a defined threshold. The computer algorithms developed as a part of the proposed work will identify anatomical features using the pressure profiles to enable pressure offloading and redistribution in an automated manner. Selective pressure offloading with dynamic pressure redistribution will reduce the key elements in pressure ulcer formation, including time and magnitude of external mechanical forces, respectively. During the first 2 years of the project, our multidisciplinary team from the University of Texas at Arlington Research Institute, Human Engineering Research Laboratories at the University of Pittsburgh, and the SCI Center at North Texas VA will be involved in developing and optimizing seat cushion prototypes that include sensorized bubble actuators, control hardware, a graphical user interface, and predictive computer algorithms. During the third year, prototypes will be evaluated using human subjects using able-bodied volunteers, wheelchair users, and wheelchair users with SCI in accordance with Institutional Review Board requirements. Results from these studies will be used to refine the cushion design and prepare the prototype for larger scale clinical testing. We anticipate that the automated seat cushion technology could replace or complement the current practice of periodic repositioning to relieve pressure without requiring caregiver or user intervention. Thus, the burden placed on caregivers, family members, and users could be reduced. The proposed software and hardware combination would eliminate the subjective nature of repositioning and offloading to help reduce injury to other areas due to undesired pressure and shear loading. Because the seat-cushion can be configured based on sensor data, it can adapt to an individual s size, shape, and weight without requiring custom seat cushion production. Most importantly, we envision that the proposed seat cushion platform could improve the quality of life of wheelchair users with SCI and provide quantitative metrics to define new guidelines for patient evaluation and care.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 29, 2016
- Source ID
- W81XWH1510719
Entities
People
- Muthu Wijesundara
Organizations
- United States Army
- University of Texas at Arlington