The earthquake in Nepal killed over 7,000 people and injured 11,000. The powerful 7.8-magnitude earthquake struck the Asian country’s capital, Kathmandu, and its surrounding areas.

Since then, rescue workers saved the lives of some people who were buried under the collapsed buildings. A radar device FINDER of the National Aeronautics and Space Administration (NASA) located and saved about four survivors after the earthquake hit on April 25 this year. The United state space agency’s device uses microwave radar technology and detects human heartbeats even under the 30 feet of debris.

The search of FINDER machine for earthquake survivors was conducted in Chautara, which is a village located slightly east of Kathmandu. According to reports, the radar technology of NASA is capable of detecting millimeter-wide movements of human heart. The NASA machine helped in successfully rescuing four Nepali persons who were trapped under debris for many days.

The survivors were men, who included two pairs of men trapped in two different buildings. They all were buried in a maximum of 10 feet of bits of stones and bricks. Reginald Brothers, undersecretary for the United States Department of Homeland Security (DHS), said “Technology's genuine test is how well it operates in a real-life setting. Tools such as FINDER can assist when the worst nightmares happen, such as the hunt for signs of Nepal earthquake survival.”

The prototype device developed by the space agency has size equal to a carry-on suitcase. While there are multiple versions of the device, the one that was used in the Nepal earthquake disaster weighed less about 9 kg, as per Buzz Feed. The device was made by NASA's Jet Propulsion Laboratory (JPL) and DHS. The machine’s radar zaps out signals and then reads them when they reflect back from the debris.