  Emergency evacuation of patients from a hospital can be challenging in the
event of a fire. Most emergency evacuation studies are based on the assumption
that pedestrians are ambulant and can egress by themselves. However, this is
often not the case during emergency evacuations in healthcare facilities such
as hospitals and nursing homes. To investigate emergency evacuations in such
healthcare facilities, we performed a series of controlled experiments to study
the dynamics of patient beds in horizontal movement. We considered a patient
bed because it is one of the commonly used devices to transport patients within
healthcare facilities. Through a series of controlled experiments, we examined
the change of velocity in corner turning movements and speed reductions in
multiple trips between both ends of a straight corridor. Based on the
experimental results, we then developed a mathematical model of total
evacuation time prediction for a patient bed horizontally moving in a
healthcare facility. Factoring uncertainty in the horizontal movement, we
produced the probability distribution of movement duration and estimated the
probability that an evacuation can be safely performed within certain amount of
time. In addition, we predicted that the evacuation time would be longer than
the prediction results from an existing model which assumes constant movement
speed. Our results from the model demonstrated good agreement with our
experimental results.
