主流式呼吸二氧化碳浓度监测系统

发布时间：2018-05-04 07:04

本文选题：呼吸监测 + 主流式　；参考：《天津大学》2014年硕士论文

【摘要】：呼吸末二氧化碳(ETCO2)在重症监护、伤员运输以及其他医疗应用中已经成为一项重要工具。2005年美国麻醉师协会(ASA)颁布的新麻监测标准中明确规定了手术中呼吸末二氧化碳监测的要求。目前基于非分光红外原理的呼吸二氧化碳浓度监测系统按照测量位置不同可分为:主流式监测方式和旁流式监测方式。主流式呼吸监测由于直接在呼吸管道上进行测量,因而具有响应速度快、不需预先处理等优点。然而被监测患者呼吸气流中复杂的干扰因素和临床应用的严格要求限制了目前主流式呼吸二氧化碳浓度监测设备在临床监测过程中的应用。本研究针对主流式人体呼吸二氧化碳浓度在临床监测过程中的特殊要求和目前不足,对传统的二氧化碳浓度监测系统进行改进,研制一种基于非分光技术(NDIR)的主流式呼吸二氧化碳浓度监测系统。该主流式呼吸监测系统采用高性能热释电红外器件和低功耗处理器件,通过采用低频调制技术和数字滤波技术准确实现对患者呼吸浓度信息的采集。之后根据人体呼吸气流不同干扰因素的特点,使用一种信号分解补偿方法对患者呼吸气流中水蒸气浓度和呼吸气流流速变化干扰进行干扰补偿,从而实时计算出被监测患者呼吸二氧化碳浓度值。最后,监测系统通过在预热阶段对自身标定系数进行线性补偿,从而实现设备在更换管道适配器后或仪器长期使用过程中的自校准功能。测试实验结果表明,该主流式呼吸系统能够方便快捷的直接在呼吸管道上对人体呼吸二氧化碳浓度进行实时连续监测,并且不需要对呼吸气体进行任何预先处理。多名志愿者监测结果显示该系统能够准确对呼吸末特征点的测量,具有良好的实时性。性能测试实验显示该系统监测误差为0.23 mmHg,长时间连续监测过程中基准值漂移在1.42 mmHg以内,说明该系统在长期临床监测过程中仍然具有较高的测量精度和良好的稳定性。因此该具备一定的临床应用价值。
[Abstract]:End of breath carbon dioxide (ETCO _ 2) in intensive care, Casualty transport and other medical applications have become an important tool. The new anesthesia monitoring standards issued by the American Association of Anesthesiologists (ASAA) in 2005 specify the requirements for monitoring end-respiratory carbon dioxide during surgery. At present, the monitoring system of respiratory carbon dioxide concentration based on non-spectroscopic infrared principle can be divided into mainstream monitoring mode and side-flow monitoring method according to the measuring position. The mainstream respiratory monitoring has the advantages of high response speed and no need of pre-processing because it is measured directly on the respiratory pipeline. However, the complex interference factors in respiratory airflow and the strict requirements of clinical application limit the application of the current mainstream respiratory carbon dioxide concentration monitoring equipment in the clinical monitoring process. In this study, the traditional monitoring system of carbon dioxide concentration was improved to meet the special requirements and shortcomings in the clinical monitoring of the mainstream human respiratory carbon dioxide concentration. A mainstream respiratory carbon dioxide concentration monitoring system based on non-spectroscopic technique (NDIRs) was developed. The mainstream respiratory monitoring system uses high-performance pyroelectric infrared devices and low-power processing devices. The collection of patient respiratory concentration information is accurately realized by using low-frequency modulation technology and digital filtering technology. Then according to the characteristics of different interference factors of human respiratory airflow, a signal decomposition compensation method is used to compensate for the disturbance of the variation of water vapor concentration and flow velocity in the respiratory airflow of patients. Thus the respiratory carbon dioxide concentration of monitored patients was calculated in real time. Finally, the monitoring system compensates its calibration coefficient linearly in the preheating stage, so as to realize the self-calibration function of the equipment after replacing the pipeline adapter or during the long-term use of the instrument. The experimental results show that the mainstream respiratory system can monitor human respiratory carbon dioxide concentration directly and directly on the respiratory pipeline in real time and continuously, and does not need any pre-processing of respiratory gas. The monitoring results of many volunteers show that the system can accurately measure the characteristic points of the end of respiration and has good real-time performance. The performance test results show that the monitoring error of the system is 0.23mmHg, and the standard value drift is less than 1.42 mmHg during the long continuous monitoring process, which indicates that the system still has high measurement accuracy and good stability in the long-term clinical monitoring process. Therefore, it should have certain clinical application value.
【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TP274

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