I have seen a program in national geography about earthquake rescue in Pakistan. British rescue team has an equipment that could find people in debris by detecting carbon dioxide from people’s breath. (I didn’t how this equipment could separate carbon dioxide we breathe from those in air)
If that equipment could work in Sichuan, it would supply huge help in researching people from debris especially 3 or 4 days after disaster. At that time, we need method or equipment to locate people in deep buried.