| abstract |
An instrument (20) for determining the concentration of a medically significant component of a sample, the instrument including a first key (54a) for selecting a function from a group of at least two functions, a second key (54b), a controller for assigning to the second key the function selected from a group of at least two functions by the first key, and a display (42) for displaying for the user an assignment by the controller of the function to the second key. |