Embodiments of the subject matter include a heart lung machine (HLM), including a plurality of actuators and a peripheral processing unit configured to receive a set of parameter data from the plurality of actuators. The HLM also may include a peripheral display device configured to present a subset of the set of parameter data and a control assembly comprising a control display device configured to present a user interface having a representation of a parameter value and an associated indication, where at least a portion of the associated indication overlaps at least a portion of the representation of the parameter value.