分析和阐释了POF光纤的包层模受抑全内反射(CMFTIR)效应及其传感机制。提出利用光纤宏弯导致模场畸变从而激发光纤包层模式的方法获得显著的CMFTIR效应并利用其实现液位传感。实验表明CMFTIR效应相对微弱,极易淹没于强背景噪声中,为此...分析和阐释了POF光纤的包层模受抑全内反射(CMFTIR)效应及其传感机制。提出利用光纤宏弯导致模场畸变从而激发光纤包层模式的方法获得显著的CMFTIR效应并利用其实现液位传感。实验表明CMFTIR效应相对微弱,极易淹没于强背景噪声中,为此通过噪声分析提出利用宏弯耦合获得暗场信号以进一步提升信噪比。设计了双绞宏弯耦合型液位探头及其封装结构。实验结果表明,暗场耦合信号具有明显的信噪比优势,实现传感器液位区分度大于3.7 d B。相较于同类液位探头,该传感器鲁棒性好,制作更加简单且成本更为低廉。展开更多
The sciatic functional index（SFI） is a popular parameter for peripheral nerve evaluation that relies on footprints obtained with ink and paper. Drawbacks include smearing artefacts and a lack of dynamic information ...The sciatic functional index（SFI） is a popular parameter for peripheral nerve evaluation that relies on footprints obtained with ink and paper. Drawbacks include smearing artefacts and a lack of dynamic information during measurement. Modern applications use digitized systems that can deliver results with less analytical effort and fewer mice. However, the systems are expensive（€40,000）. This study aimed to evaluate the applicability and precision of a self-made, low-cost infrared system for evaluating SFI in mice. Mice were subjected to unilateral sciatic nerve crush injury（crush group; n = 7） and sham operation（sham group; n = 4）. They were evaluated on the day before surgery, the 2nd, 4th and 6th days after injury, and then every day up to the 23rd day after injury. We compared two SFI evaluation methods, i.e., conventional inkand-paper SFI（C-SFI） and our infrared system（I-SFI）. Our apparatus visualized footprints with totally internally reflected infrared light（950 nm） and a camera that can only detect this wavelength. Additionally we performed an analysis with the ladder beam walking test（LBWT） as a reference test. I-SFI assessment reduced the standard deviation by about 33 percent, from 11.6 to 7.8, and cut the variance around the baseline to 21 percent. The system thus requires fewer measurement repetitions and fewer animals, and cuts the cost of keeping the animals. The apparatus cost €321 to build. Our results show that the process of obtaining the SFI can be made more precise via digitization with a self-made, low-cost infrared system.展开更多
文摘分析和阐释了POF光纤的包层模受抑全内反射(CMFTIR)效应及其传感机制。提出利用光纤宏弯导致模场畸变从而激发光纤包层模式的方法获得显著的CMFTIR效应并利用其实现液位传感。实验表明CMFTIR效应相对微弱,极易淹没于强背景噪声中,为此通过噪声分析提出利用宏弯耦合获得暗场信号以进一步提升信噪比。设计了双绞宏弯耦合型液位探头及其封装结构。实验结果表明,暗场耦合信号具有明显的信噪比优势,实现传感器液位区分度大于3.7 d B。相较于同类液位探头,该传感器鲁棒性好,制作更加简单且成本更为低廉。
文摘The sciatic functional index（SFI） is a popular parameter for peripheral nerve evaluation that relies on footprints obtained with ink and paper. Drawbacks include smearing artefacts and a lack of dynamic information during measurement. Modern applications use digitized systems that can deliver results with less analytical effort and fewer mice. However, the systems are expensive（€40,000）. This study aimed to evaluate the applicability and precision of a self-made, low-cost infrared system for evaluating SFI in mice. Mice were subjected to unilateral sciatic nerve crush injury（crush group; n = 7） and sham operation（sham group; n = 4）. They were evaluated on the day before surgery, the 2nd, 4th and 6th days after injury, and then every day up to the 23rd day after injury. We compared two SFI evaluation methods, i.e., conventional inkand-paper SFI（C-SFI） and our infrared system（I-SFI）. Our apparatus visualized footprints with totally internally reflected infrared light（950 nm） and a camera that can only detect this wavelength. Additionally we performed an analysis with the ladder beam walking test（LBWT） as a reference test. I-SFI assessment reduced the standard deviation by about 33 percent, from 11.6 to 7.8, and cut the variance around the baseline to 21 percent. The system thus requires fewer measurement repetitions and fewer animals, and cuts the cost of keeping the animals. The apparatus cost €321 to build. Our results show that the process of obtaining the SFI can be made more precise via digitization with a self-made, low-cost infrared system.
