Development of a Personal Use Seating Pressure Measurement System

Ultimate Applicability of the Research: A pressure ulcer can pose a significant threat to the health of individuals with a spinal cord injury (SCI). Individuals with SCI are vulnerable to pressure ulcers due to a combination of impaired sensory function and limited mobility. Impaired sensory function is the primary causal factor for pressure ulcer risk in individuals with SCI. In a healthy nervous system, receptors in the skin and underlying tissues detect pressure and relay painful stimuli. This critical feedback is necessary to cue action by moving to relieve discomfort and avoid damage to skin and tissue. In SCI, absence of sensation at the buttocks eliminates the natural feedback loop that leads people to move in their seats to relieve pressures at the sitting surfaces. Sitting for extended periods without performing a pressure relief can lead to a pressure ulcer.

Pressure ulcers are costly to treat, can impact quality of life and community participation, and can be life-threatening. Research has been done to identify risk factors and improve pressure ulcer prevention education provided in the clinical setting over the past two decades to help individuals with SCI manage their skin health. Despite these efforts, however, sitting-acquired pressure ulcers occur in up to 38% of individuals with SCI at any given time and contribute approximately $4 billion per year in medical expenses in the United States. While some pressure ulcer risk factors can be diminished by following clinician-recommended strategies, there are other factors that aren't as easily managed: cushion or equipment failure, change in body weight, caregiver or lifestyle change, and unforeseen events or delays causing a change in a person's routine. A problem may go undetected for several hours, and by that time, a pressure ulcer can develop.

There are two primary objectives for our project. First, we will partner with Veterans with SCI to expand development of a personal use seat interface pressure management system. The current system includes pressure-sensing hardware and a prototype mobile application. The collaborative design with Veterans with SCI will create a customizable Comprehensive Mobile Assessment of Pressure (CMAP) system. Our second objective is to test the functionality of the CMAP system with wheelchair users with SCI in their free-living environment. We will measure changes in pressure relieving behaviors (movement) in the participants when they are provided with individualized visual biofeedback on the CMAP application that displays how much pressure they have on their buttocks. This work is important because people with SCI are in need of new, more effective approaches that empower them to care for their skin, at home, during their regular routines.

Types of Patients This Research Will Help, and How It Will Help Them: This project targets pressure ulcer prevention in wheelchair users with SCI. The resulting CMAP system will provide real-time visual feedback, similar to a weather map, depicting areas and amounts of pressure on a user's seated surface. Specific and immediate feedback will prompt positional changes to relieve pressure. The individual will see immediate validation of reduced pressure via the live image on their mobile phone or handheld device.

Potential Clinical Applications, Benefits, and Risks: There are important clinical applications of this system. First, communication between patient and clinician is improved when the patient has increased capability to self-monitor their sitting behaviors and pressure distribution when sitting. Often, this information is lacking during clinical assessments and can contribute to more individualized strategies for equipment or pressure relief techniques. Second, early detection of a pressure related problem can result in early action to successfully prevent a more severe and costly ulcer.

Projected Time to Achieve a Patient-Related Outcome: During the first 2 years of this project, Veterans with SCI will participate with study investigators in the redesign of the mobile application. The second year will involve sending the finalized CMAP system home with Veterans with SCI for 6 weeks to use in their free-living environment. At the end of the 3-year period, our team will have (1) determined the priorities of Veterans with SCI for monitoring their seating pressure, (2) completed the final design of the CMAP system, and (3) tested the usability and feasibility of the CMAP system to be used in the home and community to improve the user's pressure relief movement behaviors. At the end of 3 years, this comprehensive seat pressure management system will be ready for rigorous evaluation in larger, multi-center clinical trials that assess impact on pressure ulcer prevention.