ABP waveform

An arterial line simulator with a notch that isn't drawn in

patientmonitorsimulator builds the arterial pressure trace from a forward pressure wave and a reflected one, so the dicrotic notch is a real product of that reflection, not a shape stamped onto every beat.

patientmonitorsimulator display showing a live arterial blood pressure waveform

A notch that comes from physics, not a template

The trace is the sum of a forward systolic wave moving out from the heart and a reflected diastolic wave coming back from the periphery. The dicrotic notch sits exactly where those two waves interact, plus a distinct narrow negative incisura marking the moment the aortic valve closes. Neither is hand-drawn onto the waveform; both come out of the same wave math that produces the rest of the beat.

Diastole shortens the way it actually does

As heart rate climbs, the diastolic portion of the beat compresses with the square root of the cycle length, the same relationship the QT interval follows, rather than shrinking in a straight line. A linear compression made the dicrotic notch vanish by a heart rate of about 100, which isn't how a real arterial trace behaves even in a fast patient.

The scale adapts to the patient, not a fixed range

Rather than a wide fixed mmHg axis that makes a normal 120/80 look nearly flat, the display auto-ranges to the current systolic and diastolic values with some headroom, so a normal trace fills the box the way it does on a real monitor and an abnormal one is still readable. MAP is calculated from the same numbers and shown on its own line beneath the systolic/diastolic pair.

No pulse, no trace

In pulseless rhythms (VF, asystole, PEA) the arterial line correctly goes blank rather than continuing to draw a plausible-looking pressure, since there's no real pulse pressure behind it to display.