Pressure signal transmission of five commercially available oesophageal balloon catheters

Objective: Five commercially available oesophageal balloon catheters (OBCs) were tested to evaluate the accuracy in transmitting fast-changing pressure signals which can be observed, for example, during phrenic nerve stimulation. Setting: Research laboratory of a university hospital. Method: The OBCs tested varied in length (900-1390 mm) and inner diameter (0.9-1.5 mm) as well as in balloon material [latex or polyvinylchloride (PVC)]. A 180-cm tube served as a control. A sudden pressure drop was generated by the explosion of a pressurized latex balloon. The time between the pressure drop and 75, 50, 25 and 10% of the maximal pressure was measured. Results: The time intervals required to transduce a pressure drop of 90 % varied between the different OBCs from 85 to 476 ms(control 32 ms). Transmission time was lower in OBCs with a larger inner diameter. Shortening the OBCs resulted in a further decrease in transmission time. Conclusion: The type of OBC used has an impact on signal processing. An OBCs with a short transmission time should be chosen, especially if fast pressure changes are to be evaluated such as during phrenic nerve stimulation.