There is a widely held belief that a food item, dropped on the floor but picked up again within 5 seconds, remains sufficiently untainted to be safe to eat. Recent studies have come to the conclusion that "well, it depends." This idea is for both an algorithm and a device that would take into account
those dependencies.
The algorithm itself will remain undetailed here, as it is currently under study and development, and will probably be at about ver 4.7 before you would want to trust it; just suffice it to say that the existence of the algorithm would be a prerequisite to the device.
The device will simply be a modified cell phone; most are currently capable of running a quite a lot of software. This add-on requires only minimal hardware updates. The two hardware requirements are a camera (currently common) and an accelerometer (not quite so common).
A number of factors would go into the calculation of a "go/no go" decision; the Estimator makes it easy to remember them via a series of prompts.
In breif, the variables which will be analyzed by the software are: duration of contact (this is actually only marginally determinitive, thus this whole idea), makeup and structure of food item, surface properties of floor, and floor cleanliness.
So, a demonstration is in order.
"Ooops!... thousand two onethousand three onethou - <grab> got it!" (looks dubiously at item)
"You gonna eat that?"
"Dunno, I'll check." (pulls out cell phone, goes to Safety Estimator menu).
[Time on floor]-> 2.4 seconds
[Hardness of food item, 1-10 or select similar item from menu]->moist cake
[Solidity of floor, 1-10 or drop phone on surface]->(thunk)
[Take image of floor]->(click)
[Wipe floor with hand]->(swish)
[Re-image floor]->(click)
[Calculating...]
[The item is safe, probably. Click for disclaimer]
"Hey, what did you do with my Twinkie?!"