Dynamic Response is a function of Natural Resonant Frequency and Damping Coefficient
The Natural Resonant Frequency: How fast the system vibrates in response to a pressure signal
The Damping coefficient: How quickly those vibrations come to rest in the system
The Square Wave Test
This is the "square wave".
The accurate, responsive, adequately damped arterial line waveform
A good art line trace has a distinct dicrotic notch, and after the fast flush test there are two oscillations only.
The over-damped arterial line waveform
The over-damped trace will lose its dicrotic notch, and there wont be more than one oscillation.
This happens when there is clot in the catheter tip, or an air bubble in the tubing.
The under-damped arterial line waveform
The under-damped trace will overestimate the systolic, and there will be many post-flush oscillations.
The MAP remains the same in spite of damping.