Measurement system of body shift during Head of Bed elevation based on robust tracking of mattress edges using LIDAR

This paper proposes a contactless measurement system for body shift on the mattress during Head of Bed (HOB) elevation to investigate detail mechanism about how body shift causes discomforts and pressure ulcer. For contactless measurement, one LIDAR captures the distance from the mattress edges to the shoulder, which means the upper part of body movement distance. The other LIDAR measures the distance to the foot, which represents that the lower part of body sliding. Since contours of mattress and body surface change dynamically during HOB elevation, the robust measurement is difficult. To overcome various changes of contour, a particle filter is used for robust tracking of the mattress edges and the foot plantar. The experiment about tracking performance and distance measurement demonstrated feasibility of our system in practical settings.