Imagine plopping six cups of coffee grounds on the heads of patients just before they are wheeled into the operating room to have nose or throat surgery?
 
In essence, that is what a team of Vanderbilt University engineers are proposing in an effort to improve the reliability of the sophisticated “GPS” system that surgeons use for these delicate operations. They have designed a “granular jamming cap” filled with coffee grounds that does a better job of tracking patient head movements than current methods. They disclosed the novel design and data on its effectiveness at the International Conference on Information Processing in Computer-Assisted Interventions in Barcelona on June 20.
 
Of course, the coffee grounds are not loose: they form a thin layer inside a stretchy silicone headpiece, which looks something like a black latex swim cap decorated with reflective dots. After the cap is placed on the patient’s head, it is attached to a vacuum pump that sucks the air out of the cap, jamming the tiny grounds together to form a rigid layer that conforms closely to the shape of the patient’s head. (This is the same effect that turns vacuum-packed coffee into solid bricks.)

The ful article originally appeared on Vanderbilt University’s website.