Earlier bagless vacuums, including Dyson's, deposit most of the collected dust into the drum - but the really fine particles remain in the airstream until they are caught in the exhaust filter or filters.
As those filters collect dust the airflow becomes obstructed and the suction decreases, much as happens when an old-school vacuum bag becomes full. Cleaning a filter is a messier and more unpleasant job than just emptying a bagless vacuum's canister.
How did Dyson manage to dump the dust filter? Senior design engineer Martin Peek told iTWire that the project took six years from the original brief.
The solution was to fit a flexible tip to the nozzle. The tip then oscillates in the spinning airflow, and that movement keeps it clear.
But the degree of flexibility had to be exactly right. Too stiff, and blockages still occurred. Too flexible, and the nozzle collapses like a blocked drinking straw.
Getting the tips right took around three years, but it was worth it: the final design - dubbed 'Cinetic' (pronounced 'kinetic') - was tested to the equivalent of 10 years of domestic use and showed no loss of suction.
"It's an amazing achievement - you buy it, you use it; that's it," said Mr Peek.
Please read on for more on the DC54's performance, and news of Dyson's latest cordless vacuum.