title: Determination of frequency response from step response: application to fluid-filled catheters.
abstract: The performance of a fluid-filled catheter can be described by reporting its undamped natural frequency and damping ratio. These parameters can be measured by subjecting the catheter to sinusoidally varying pressures at a wide variety of frequencies to obtain the frequency response. They can also be computed from the response to a step change in pressure, which is often easier to produce. This paper derives the required equations and includes a graph which permits one to look up the undamped natural frequency after measuring the period and decay rate of the oscillation following a step change in pressure.
mesh_terms: D006328:Cardiac Catheterization / Q000295:instrumentation*; D008433:Mathematics; D009991:Oscillometry / Q000379:methods*; D055585:Physical Phenomena; D010825:Physics; D011312:Pressure