Dynamic response of the ROSE damping device.

Methods used in clinical practice to increase the damping of a transducer hydraulically coupled to an intraarterial blood-pressure monitoring system often decrease the undamped natural frequency of the system. This leads to spuriously high systolic and low diastolic pressure readings. The ROSE damping device is being marketed as a possible solution to the problem. We tested the dynamic response of three different catheter systems, with various pressure-tubing lengths of 1 to 7 feet (30.5 to 213.4 cm), with and without the ROSE damping device. The device was able to substantially increase damping and at the same time maintain the undamped natural frequency. Typically it increased the damping coefficient from a minimum of 0.17 +/- 0.01 to a minimum of 0.33 +/- 0.01, while never significantly decreasing the undamped natural frequency. In testing a sample of 25 devices we did observe, however, a wide variability in damping characteristics among different devices. Damping coefficients ranged between 0.19 and 1.20.