a pulse oximetry user interface has a display and a plurality of views each configured to occupy the display . each of the views are adapted to present data responsive to a physiological signal . a plurality of icons are configured to occupy a portion of the views and adapted to designate the content of the views . further , a plurality of keys are proximate to the display and correspond to the icons so as to select the icons . one of the views is a pleth view that presents a pulse waveform . another one of the views is a trend view that presents a trend graph . at least one of the icons can be selected so as to switch the display between the pleth view and the trend view .