光纤式脉搏与呼吸检测方法及实验研究

发布时间：2018-03-05 05:14

本文选题：光纤布拉格光栅　切入点：桡动脉脉搏波　出处：《天津大学》2016年硕士论文　论文类型：学位论文

【摘要】：光纤本身所具有的宽带、大容量、低损耗、体积小、耐腐蚀、电绝缘、抗电磁干扰等优势,使得光纤传感器在复杂环境条件中,如桥梁结构、航空航天、石油开采、电力传输等得到了广泛的应用。不仅如此,光纤传感器在生物医学检测领域也受到越来越多的重视。与传统的电学传感器相比,光纤传感器不需要前端放大装置,传感探头体积小的优势适合医学微创生理信息检测,此外光纤传感器还具有抗电磁干扰的优势,特别适合在MRI、太空等复杂电磁环境下的生理信息检测。本文的主要研究目的是利用光纤布拉格光栅应变检测原理、光纤微弯效应、模式干涉原理,实现桡动脉脉搏波和呼吸波的获取与分析。本文的主要研究内容如下:首先,针对脉搏波信号微弱的特性,设计基于杠杆原理的力学增敏机构,并建立力学传感模型,分析了影响传感器灵敏度的主要因素。搭建了测试系统,并测试了K值为6.2:1和0.35:1两种条件下的传感器灵敏度,结果表明,K=6.2:1的情况下传感器的具有更高的力学灵敏度为8.236 nm/N。此外,按照中医脉诊的要求测量了不同位置及深度下的脉搏波波形,并与电学脉诊仪相比。实验结果表明,该测量装置适用于中医脉诊。其次,基于单模光纤微弯损耗的基本原理,设计了光纤微弯呼吸传感器。分析了不同弯曲半径和弯曲周期对传感器弯曲损耗灵敏度的影响,并实验验证。测量结果表明,对于1550 nm的光源,单模光纤的弯曲半径在3-6 mm范围内变化,弯曲周期数为4时传感器的弯曲损耗灵敏度最高。最后进行了人体呼吸传感实验,验证了该传感器应用于呼吸检测可行性。最后,提出了一种基于模式干涉原理的光纤呼吸传感器。传感器是采用多模-单模-多模(MSM)级联的方式实现高阶模式的激发,并产生模式干涉。理论分析了传感器的应变检测原理,搭建了试验系统,并测试了该传感器的灵敏度。实验结果表明该传感器具有53.6 pm/μm的位移灵敏度。最后进行人体呼吸信号的检测。
[Abstract]:Optical fiber has the advantages of wide band, large capacity, low loss, small size, corrosion resistance, electrical insulation, electromagnetic interference resistance and so on, making optical fiber sensors in complex environmental conditions, such as bridge structure, aerospace, oil mining, Electric power transmission has been widely used. Not only that, fiber optic sensors have been paid more and more attention in the field of biomedical detection. Compared with traditional electrical sensors, optical fiber sensors do not need front-end amplifiers. The small size of the sensor probe is suitable for medical minimally invasive physiological information detection. In addition, the optical fiber sensor also has the advantage of anti-electromagnetic interference. The main purpose of this paper is to use the principle of fiber Bragg grating strain detection, fiber micro-bending effect, mode interference principle, the main purpose of this paper is to make use of the principle of fiber Bragg grating strain detection, fiber micro-bending effect, mode interference, and so on. The main contents of this paper are as follows: firstly, according to the weak characteristic of pulse wave, a mechanical sensitizing mechanism based on lever principle is designed, and a mechanical sensing model is established. The main factors affecting the sensitivity of the sensor are analyzed. A testing system is set up, and the sensitivity of the sensor under the conditions of K = 6.2: 1 and 0.35: 1 is tested. The results show that the sensor has a higher mechanical sensitivity of 8.236 nm / N under the condition of K = 6.2: 1. The pulse waveforms at different positions and depths were measured according to the requirements of traditional Chinese medicine pulse diagnosis. The experimental results show that the measuring device is suitable for traditional Chinese medicine pulse diagnosis. Secondly, based on the basic principle of single-mode optical fiber micro-bending loss, An optical fiber micro-bend respiratory sensor is designed. The effects of different bending radius and bending period on the sensitivity of the sensor are analyzed and verified by experiments. The measurement results show that, for the 1550nm light source, The bending radius of single-mode optical fiber varies in the range of 3-6 mm, and the bending period number of 4:00 sensor has the highest sensitivity of bending loss. Finally, the human breathing sensing experiment is carried out, and the feasibility of applying the sensor to respiratory detection is verified. A kind of optical fiber respiratory sensor based on mode interference principle is proposed. The sensor adopts multi-mode single-mode multi-mode MSM cascade to realize the excitation of high-order mode and produce mode interference. The principle of strain detection of the sensor is analyzed theoretically. An experimental system was set up and the sensitivity of the sensor was tested. The experimental results show that the sensor has a displacement sensitivity of 53.6 pm/ 渭 m. Finally, the human respiratory signal is detected.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：R241;TP212

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