Though many governmental and nongovernmental efforts for disaster prevention have been sought throughout Japan since the Great East Japan Earthquake on March 11, 2011, most of the preparation efforts for disasters have been based more on structural and conventionalized regulations than on scientific and objective grounds.

There has been a lack of scientific knowledge for space utilization for triage posts in disaster drill sessions. This report addresses how participants occupy and make use of the space within a triage post in terms of areas of use and occupied time.

The trajectories of human movement by using Ubiquitous Stereo Vision (USV) cameras during two emergency drill sessions held in 2012 in a large commercial building have been measured. The USV cameras collect each participant's travel distance and the wait time before, during, and after undergoing triage. The correlation between the wait time and the space utilization of patients at a triage post has been analyzed.

In the first session, there were some spaces not entirely used. This was caused largely by a patient who arrived earlier than others and lingered in the middle area, which caused the later arrivals to crowd the entrance area. On the other hand, in the second session, the area was used in a more evenly-distributed manner. This is mainly because the earlier arrivals were guided to the back space of the triage post (ie, the opposite side of the entrance), and the late arrivals were also guided to the front half, which was not occupied by anyone. As a result, the entire space was effectively utilized without crowding the entrance.

This study has shown that this system could measure people's arrival times and the speed of their movements at the triage post, as well as where they are placed until they receive triage. Space utilization can be improved by efficiently planning and controlling the positioning of arriving patients. Based on the results, it has been suggested that for triage operation, it is necessary to efficiently plan and control the placement of patients in order to use strategically limited spatial resources.

OhtaS, YodaI, TakedaM, KuroshimaS, UchidaK, KawaiK, YukiokaT. Evidence-based Effective Triage Operation During Disaster: Application of Human-trajectory Data to Triage Drill Sessions. Prehosp Disaster Med. 2015;30(1):1-8.