This post is also available in: heעברית (Hebrew)

Room clearing is part of military operations in urban terrain, close-quarters combat, and active-shooter responses. This complex and risky action involves the identification of the number of troops entering the room, predicting the shape of the room, considering the size of each step, and avoiding “flagging,” or pointing one’s weapon in the direction of fellow teammates.

A US patent issued recently offers a tiny motion detector for marking and monitoring cleared rooms. The invention could be an attractive solution for SWAT teams, Delta, or DEVGRU (Seal Team 6).

The technology is a combination LED and sensor that both marks when military or police forces have cleared a room and alerts when a potential hostile person has entered a cleared area. The solution, demonstrating increased functionality and ease-of-use was invented by a team from the US Naval Information Warfare Center-Atlantic. 

With current solutions, the military and law enforcement use colored chemical light sticks (known as chemlights or glow sticks) to indicate that a room has been cleared. However, using infrared motion sensor technology, the Navy’s new devices are small, lightweight and alert users when the clearance status of a room has changed, as reported by

“The present invention serves as a force multiplier, allowing the military or law enforcement team to not leave a member behind in order to ensure that a previously cleared room is reentered,” according to the Navy’s new patent.

The LEDs can also display in various colors, indicating the status of the room and changing if someone enters. The devices, which can be fitted with additional features such as the ability to take still photographs and videos, consume very little power and can be left behind or reused.

With the help of technology transfer, private businesses can leverage the Navy’s research and development work to integrate this and other military inventions into their own products and services.