The role of a gel filled tip in maintaining the frequency response of telemetry based blood pressure measurements

Abstract

In recent years, measurement of blood pressure via telemetry in a variety of laboratory animals has become an indispensable part of cardiovascular physiology, drug development and safety pharmacology. The solution provided by Data Sciences Inc almost 20 years ago is in the form of a catheter attached to a pressure sensor and wireless link to a remote receiver. This design features a catheter made of compliant tubing and filled at the tip with a gel material. This gel was suggested to contribute to the frequency response of blood pressure telemetry system. However, the actual influence of the specialized tip on the dynamic response of the pressure sensor has not been reported. In the present experiment, we investigated the role of the specialized gel‐filled catheter tip in the frequency response of fluid filled catheters. Experiments were carried out using a custom made sinusoidal pressure generator and the data analyzed using Labview software. The experiments reveal that the bandwidth of the DSI system is ultimately limited to less than 100 Hz by the low power transmission system and not the gel tip catheter. When a high bandwidth transmission system is available, −3 dB bandwidths of 400 Hz are attainable for rat sized catheters. The results of the study suggest that the gel tip reduces the frequency response slightly when compared to a tip‐less catheters but not to the extent that the blood pressure measurements are compromised.