US 9,134,205 B2, system and method for removing surface particles from an object.
The clever part is not the jet, it is the looking. An image sensor scans the surface, a person, a piece of luggage, whatever, across infrared, visible and ultraviolet light, watching for particles whose spectral signature matches something worth finding: explosive residue, a biological agent, anything with its own optical fingerprint.
Only once something is flagged does a steering mechanism aim a fluid jet, gas or liquid, continuous or pulsed, at that exact spot to knock it loose. Whatever comes off is captured and run through mass spectrometry or similar analysis to confirm what it actually was. Everything else on the surface is left alone. The system spends its force on the one particle it already suspects, not on a general sweep.
The detect-then-remove shape of it: a mixed field of particles where only some types are worth anything, a scoring split between what you dislodged and what you actually recovered, and an analysis line reporting what the last thing captured turned out to be, the same role the patent's mass spectrometer plays.
The real device uses a fluid jet, not a beam of light. Dust Off moved it up the spectrum to lasers because a beam you can see and aim reads better on a screen than a puff of gas, and the site already had an EM spectrum to hang that joke on.
More importantly, the patent's whole point is that a person does not have to aim it: the sensor spots the target and the jet follows automatically. The game hands you that job instead and puts a clock on it, because watching an algorithm work is not a game, doing its job under pressure is.
US 9,134,205 B2 · Hillis, Hyde, Kare, Ishikawa, Wood · Elwha LLC, granted 15 September 2015.