In Line Monitoring of Carbon Dioxide Via a Gas Permeable Window

Abstract

The concept of monitoring oxygen tension in a bypass loop, by using an oxygen sensor placed against a gas permeable “window” incorporated into the loop, has been previously reported by the authors¹. This system is now in routine clinical use (Cardiomet 1000, Orange Medical Instruments, High Wycombe, England). This technique has several clinical advantages. Firstly, the sensor is separated from the circulating fluid by a sterile barrier and need not therefore be sterile. Secondly, the sensor can be removed from its connector at any time to allow the calibration to be rechecked without jeopardising loop sterility. Finally, since the oxygen sensor is provided with its own diffusion membrane, calibration is easily performed using air and a zero solution.