Vital signs

摘要

Searching for survivors after a disaster is always a race against time - although often many of the rescues can and are done by bystanders and initial crews attending by the primary surface search and light debris removal. Where victims are still trapped under the collapse, technical search equipment is required. The USAR teams today carry some well researched and well developed equipment to carry out these searches. Experience has shown that very frequently victims trapped in a building collapse can hear their rescuers, but can not be heard themselves outside of the rubble pile. However, if the victims can tap, scratch, or move, the collapsed structure carries these sounds effectively. These sounds are not heard by the human ear, but they can be picked up by electronic listening devices.