Abstract
We contrived a method for real-time volumetry of balloons for IABP by measur-ing the electrical impedance. In this method, the impedance was measured continuously between two electrodes at both ends of the balloon within a rigid tube, which was filled with saline solution. Balloon volume (VB) was calculated following equation. VB=(RI-RD)V0/RI, (RI, RD: impedance value at inflation and deflation state of balloon, respectively. V0: tube volume between electrodes). We evaluated the performance of 6 balloons (Kontron 40 ml 9 Fr, Datascope 34ml 9.5 Fr, Boston_ Scientific 40 ml 10 Fr, 30 ml 9.5 Fr and Tokai Medical Products 37 ml 10.5 Fr, 22 ml 9.5 Fr) and 4 driver systems (Kontron KAAT, Datascope system 90 T, Boston Scientific Cardiac Assist 3001 and Toyobo VCT 30). Results showed different driving pressure-balloon volume loops and responses. And each driver system had specific working characteristics. We conclude that recognition of characteristics of driver system is important to use IABP safely and appropriately, and care should be taken when a balloon is used in conjunction with different manufacturer's driver system.
