Development of the Wheelchair In-Seat Activity Tracker (WiSAT)
Abstract
Sitting is a common functional posture for all persons. After a spinal cord injury (SCI), sitting becomes more complicated and can have medical and functional consequences. Pressure ulcers remain the most costly and disruptive secondary complication of SCI and adversely impact activities of daily living, employment, and overall quality of life. All people with SCI who use a wheelchair are at high risk of developing pressure ulcers because they sit throughout the day and have poor or absent sensation in their buttocks. Wheelchair users are prescribed cushions in an attempt to prevent the formation of pressure ulcers. They are also taught to perform pressure reliefs and weight shifts throughout the day. Pressure reliefs consist of leans or push-ups and are designed to unweight buttock tissues to prevent pressure ulcers from occurring. While education about skin care is an important part of SCI rehabilitation, research has shown that persons with SCI do not perform pressure reliefs with the frequency that they have been taught. The objective of this project is to design, develop, and evaluate new technology to assist persons with SCI to increase and maintain activity consistent with improved tissue health. The proposed device, termed the Wheelchair in-Seat Activity Tracker (WiSAT), can be considered as similar to other activity trackers that are used by people to monitor healthy behaviors. The WiSAT will empower wheelchair users with knowledge about their behaviors that are associated with pressure ulcer prevention. The rationale for designing a new device is based upon our recent research into in-seat behaviors of wheelchair users. This research was motivated by the hypothesis that wheelchair users should be encouraged to move within their seat and to perform functional activities that alter the loading on their buttocks. In short, we set out to study the hypothesis that ?just because one sits, doesn?t mean one should sit still.? This line of research produced four important findings: (1) changes in posture -- often performed during functional movements -- can have a large impact on buttock blood flow and pressure -- two parameters the are linked to pressure ulcer causation; (2) persons with SCI do not adhere to their pressure relief regimen as taught during rehabilitation; (3) persons with recent SCI perform weight shifts and pressure reliefs much more than persons with long-term SCI; and (4) persons without a history of pressure ulcers perform 2.5 times more weight shifts than persons with a history of pressure ulcers. An activity monitor that measures and reports in-seat activity is one tool that can be used to encourage more in-seat movement. The WiSAT will be based upon our hardware used to measure the in-seat movement of full-time wheelchair users. This research hardware consists of a force-sensing mat and a data logger that fully resides inside the wheelchair cushion cover. The mat is placed underneath the wheelchair cushion so that its presence does not affect cushion performance. If placed on top of the cushion, it would alter the surface upon which the buttocks are positioned and impact cushion performance. Because a consumer product is much different than instrumentation used for research, extensive research and development activities are proposed. This project will use a user-centered iterative approach to develop a commercially ready prototype. Three subsystems, hardware, a mobile phone app, and classification algorithms, will be designed and evaluated before being configured into a functional WiSAT system. The system will then undergo short-term and longer-term usability studies to assess acceptance, usability, and impact in affecting in-seat activity. Given the formative work on the proposed technology and the interest received from commercial entities, we believe commercial availability of the WiSAT represents a short-term impact, while the WiSAT will provide a longer-term im
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 07, 2017
- Source ID
- W81XWH1710221
Entities
People
- Stephen Sprigle
Organizations
- Georgia Tech Research Corporation
- United States Army