Influence of the marvelous™ three-way stopcock on the natural frequency and damping coefficient in blood pressure transducer kits

Abstract

Two types of Planecta™ ports are commonly used as sampling ports in blood pressure transducer kits: a flat-type port (FTP) and a port with a three-way stopcock (PTS). Recently, a new type of three-way stopcock (Marvelous™) has been released as a Planecta™ counterpart, but its effects on the frequency characteristics and reliability of blood pressure monitoring have not been investigated. We assessed the influence of the Marvelous™ stopcock on the frequency characteristics of the pressure transducer kit. The basic pressure transducer kit, DT4812J, was modified by replacing one or two of the original three-way stopcocks with Marvelous™ stopcocks. The frequency characteristics (i.e., natural frequency and damping coefficient) of each kit were determined using wave parameter analysis software, and subsequently evaluated on a Gardner chart. Replacement of the original blood pressure transducer kit stopcocks with Marvelous™ stopcocks decreased the natural frequency (48.3 Hz) to 46.3 Hz or 44.8 Hz, respectively; the damping coefficient was not significantly changed. Plotting the data on a Gardner chart revealed that the changes fell within the adequate dynamic response region, indicating they were within the allowable range. Insertion of Marvelous™ stopcocks slightly affects the natural frequency of the pressure transducer kit, similar to inserting a PTS. The results indicate that the Marvelous™ stopcock is useful for accurate monitoring of arterial blood pressure, and may be recommended when insertion of two or more closed-loop blood sampling systems is necessary.

Journal of clinical monitoring and computing end of year summary 2018: hemodynamic monitoring and management

“…Through 2018, we also saw a few papers in the area of technical development. Fujiwara and colleagues [36] validated a newly developed three-way stopcock and showed that the natural frequency and damping coefficients were not altered to a clinically relevant extent even when three stopcocks were inserted serially before the pressure transducer. The new stopcock appeared a safe substitute for existing stop-cocks in terms of the frequency response, while also offering improved features to help preventing contamination.…”