The Economist January 25, 2020 pp68-69 Science&technology reports “Personal Identification, Finding it in one’s heart” “People can now be identified at a distance by their heartbeat”
Currently armed-forces use facial features or gait to help identify adversaries. As good as these methods are, they are easily circumvented. American defense agencies, working collaboratively, have “now developed a new tool for the job.” Called “Jetson”, the laser device is a “vibrometer” capable of detecting our heartbeat by evaluating exceedingly small movements in our clothing. A movement away from or towards the laser as small as 0.000,000,000,010 meter or 10 picometers can be detected. These data, collected in as little as 30 seconds, create a signature file or heartprint record. Newer devices, not dependent on the infared spectrum but using radiowaves maybe even more effective. There are likely many applications including lie-detection, user authorization and medical diagnostics. Read the article for more detail.