Measurement of Dynamic Forces Applied to Skin During Lateral Patient Transfers Using the ALTA System

Alternative patient transfer methods and systems are required to improve transfer safety and experience for patients and staff. Current sling and other transfer methods to lift or move patients apply forces to the patient that cause injury, especially for patients with frail skin or other conditions that put them at risk. New solutions must also reduce the risk for staff injuries associated with the physical labour required to transfer patients using slings or other systems. This paper assesses the forces applied to adult mock patients and adult-size manikins using the Able Innovations ALTA transfer system; a new alternative lateral transfer system. A novel sensor is used that was developed to measure normal and shear forces applied to skin. Increased normal forces can cause injury through contusions. This paper shows that with the ALTA transfer system the patient experienced an increased normal force of ~50% over their normal body weight, reduced from an increase of >300% previously reported for sling transfers. Shear forces can cause injury through skin tears with 14.5N shown to cause tissue damage. Again, this paper shows a maximum shear force of 1.4N during transfer that is substantially lower than the 8N shear force previously reported for sling transfers. The work also shows the challenges associated with the measurement of dynamic forces within a complex interaction between a mechatronics system and human subject.