Motor control solution aids point-of-care analysis

The Clinitek Status point-of-care analyser automatically analyses urine strips, eliminating the errors that can arise from human visual judgements. It is particularly simple to use because of a touch-screen user interface, and a motorised drawer that accepts the reagent strip or cassette and automatically positions it under the instrument’s optical analysis sensors. This drawer was the focus of Cambridge Consultants’ engineering effort. The motion control solution that Cambridge Consultants devised involved a heavier-duty motor and gearbox than had been used in previous systems. It was also specifically located to ensure that force on the drawer can never damage it. This was combined with electronic circuit advice to assist the Bayer team in the design of an improved control and drive strategy. This involved sensing the insertion of the drawer by feedback from the motor windings, and driving the motor in a more sophisticated way, with a special motion profile that improves both the engagement process and the final positioning of the reagent under the optics.