A flowing liquid test system for assessing the linearity and time-response of rapid fibre optic oxygen partial pressure sensors

The development of a methodology for testing the time response, linearity and performance characteristics of ultra fast fibre optic oxygen sensors in the liquid phase is presented. Two standard medical paediatric oxygenators are arranged to provide two independent extracorporeal circuits. Flow from either circuit can be diverted over the sensor under test by means of a system of rapid cross-over solenoid valves exposing the sensor to an abrupt change in oxygen partial pressure, PO2PO2. The system is also capable of testing the oxygen sensor responses to changes in temperature, carbon dioxide partial pressure (PCO2PCO2) and pH in situ. Results are presented for a miniature fibre optic oxygen sensor constructed in-house with a response time ∼ 50 ms and a commercial fibre optic sensor (Ocean Optics Foxy), when tested in flowing saline and stored blood.

► We design a dual extracorporeal blood/liquid flow test rig for testing the response time of rapid intravascular fibre optic blood gas sensors. ► We demonstrate that the electromechanical cross over switch has a response time of 50 ms. ► Our miniature fibre optic PO2PO2 sensor is shown to have a response time of less than 75 ms in flowing liquid.