Clinical and laboratory evaluation of four catheter-transducer systems.

This study was conducted to examine four catheter-transducer systems and their variations that were found clinical. The dynamic response characteristics (f[n] and zeta) were determined for each system in both a laboratory and clinical setting. These dynamic responses characteristics provided information about each system in regard to its ability to faithfully reproduce a pressure waveform. From this study it was found that the simpler catheter transducer system has more adequate dynamic response characteristics and thus was more capable of faithfully reproducing the pressure waveforms. The membrane dome was found to be equal in function with the non-membrane dome provided that the manufacturer’s recommended method of attachment, i.e., water instillation on the transducer diaphragm and pressure distension of the dome membrane, was adhered to. It was determined that extension tubing was detrimental to the system’s dynamic response characteristics and, moreover, impedes faithful waveform reproduction. With regard to the pulmonary artery catheter transducer system, it was found that the use of extension rubbing results in an undesirable elongation of the system. In all clinical trials of the pulmonary artery catheter-transducer system, the dynamic response characteristics were over-damped. Finally, it was ascertained that response testing may be easily performed in the clinical setting and provides valuable information with regard to the adequacy of each system. This testing allows for determination of the accuracy of the reproduced waveform to the original patient waveform.