A reflection-mode fibre-optic sensor for breath carbon dioxide measurement in healthcare
A reflection-mode fibre-optic sensor for breath carbon dioxide measurement in healthcare
复制标题
用于医疗保健中呼吸二氧化碳测量的反射模式光纤传感器
DOI：
10.1016/j.sbsr.2018.100254
复制
发表时间：
2019-02-01
影响因子：
5.3
通讯作者：
Korposh, Serhiy
中科院分区：
文献类型：
--
作者：
Liu, LiangLiang;Hao, FengHuan;Korposh, Serhiy
基于pH指示染料百里酚蓝的比色变化，研制了一种反射式CO2光纤传感器。所述CO2传感膜包含百里酚蓝和以离子对形式掺杂在有机改性的二氧化硅膜中的四甲基氢氧化铵。进行浸涂工艺以在光纤的尖端上涂覆膜厚度约为2.7 +/-0.1 μ m的传感膜。在波长为608 nm处观察到的反射信号表现出可逆的变化，从0到6%的CO2浓度范围内的响应时间为19 s和恢复时间为170 s的6%的CO2。发现在提供最高灵敏度的涂覆溶液的制备中百里酚蓝的最佳浓度为2.9mg/ml。将FOS储存在纯氮气气氛中提供了具有超过15天的保质期的稳定膜，相比之下，在环境空气中储存10天后，膜性能逐渐退化并且灵敏度完全丧失。FOS响应受相对湿度（RH）的影响，湿度过滤器被证明可以将呼吸中的湿度水平从90%降低到40-50%，以减少这种影响。将所开发的FOS用于测量潮气末呼吸CO2，以测试其在医疗保健中的适用性。使用我们的FOS对呼吸样本进行的CO2测量显示出与商业CO2数据记录器（K-33 BLG，CO2 Meter，USA）的良好一致性（误差百分比约为3%）。由于响应时间的限制，目前FOS仅限于测量从缓慢呼吸到呼吸的CO2的变化。
A reflection-mode carbon dioxide (CO2) fibre optic sensor (FOS) is developed based on the colorimetric change of pH indicator dye thymol blue. The CO2 sensing film comprises thymol blue and tetramethylammonium hydroxide in the form of an ion pair doped in an organically modified silica film. A dip coating process was conducted to coat the sensing film on the tip of optical fibre with a film thickness approximately 2.7 +/- 0.1 mu m. The observed reflection signal at a wavelength of 608 nm exhibits a reversible change for the concentration of CO2 range from 0 to 6% with a response time of 19 s and recovery time of 170 s for 6% of CO2. An optimal concentration of thymol blue in the preparation of coating solution that provides a highest sensitivity was found to be 2.9 mg/ml. Storing the FOS in a pure nitrogen atmosphere provided a stable film with a shelf-life of over 15 days as compared to a gradual degradation in film performance and complete loss of sensitivity after 10 days with storage in ambient air. The FOS response is affected by relative humidity (RH) and a humidity filter was demonstrated to reduce humidity levels in breath from 90% to 40-50% to reduce this effect. The developed FOS was used to measure the end-tidal breath CO2 for testing its applicability in healthcare. The CO2 measurement from breath sample using our FOS shows a good agreement (percentage error similar to 3%) with a commercial CO2 datalogger (K-33 BLG, CO2 Meter, USA). Due to the limitation of response time, at present the FOS is limited to measuring variation of the CO2 from slow breath to breath.