Some ranges display as quarter circles, others display as half circles. A
quarter circle displays when the value has a physiologic normal level at one
end of the range. A half circle displays when the value has a physiologic
normal level in the middle of the display range.
In the example below, the SpO2 gauge is shown as a quarter circle, where
values lower than 88% will trigger an alarm, and the PR gauge is shown as a
half circle, where values below 50 bpm and above 140 bpm will trigger an
alarm.