US Special Forces laser can ID your heartbeat from over 600 feet away

In the mobile world, there are arguments over the accuracy and security of biometrics such as fingerprints, irises, and faces. In the security and military sectors, however, people are turning to heartbeats. Just like fingerprints, the cardiac signature of a person is believed to be unique and infallible. But unlike fingerprints, heartbeats can be measured secretly from a distance with a laser. And wouldn't you know it, the US military has one exactly like that.

Cardiac signature can be measured remotely in one of two ways. The most common would be to use an infrared sensor to detect changes in the direction of reflected light. While it does work, it only works at certain distances and can be blocked by most clothing and objects.

A newer technique called laser vibrometry uses an infrared laser to detect surface movement caused by the heartbeat. Its advantage is that it can be used from longer distances and passes through shirts and jackets, though not through thicker material.

This technology has caught the eye of Pentagon and had a prototype developed for it. It could offer better and more accurate identification than facial recognition, especially when it's impossible to catch the face at a good angle. It does require a database of cardiac signatures to compare it with, but it's also possible to record suspects' heartbeats first even before they're identified.

The device, currently called Jetson, works at a distance of 200 meters – around 650 feet – but that can be increased by using a better laser. The current system uses an off-the-shelf laser designed to track vibration in large structures such as wind turbines, combined with a special stabilizing gimbal to keep it locked onto the correct spot on the chest. There's still room for improvement: right now a reading takes around 30 seconds to record, which means the subject has to be stationary for that period.

As for range, while the idea of a satellite that could spot a terrorist's heartbeat out of a crowd from space is still effectively fiction, the inventors of the device suggest longer distances than what's offered now are certainly possible. Whether that's preferable to facial recognition or other means of biometric identification will depend on the circumstances.