基于头罩稀释法的间接能量测试方法及其应用研究

发布时间：2018-05-16 17:10

本文选题：间接测热法 + 静息代谢率　；参考：《中国科学技术大学》2017年博士论文

【摘要】：营养不良是指因能量或营养素的不平衡而对人体产生有害影响的一种营养状态,营养不良及其造成的住院病人重要生命器官受损和大众健康领域的慢病高发已成为住院病人面临的巨大风险和重要的公共健康问题。通过测量人体代谢速率和代谢底物,确定营养需求,进而进行合适的营养支持,是防治营养不良的有效手段。在代谢测量方法中,间接测热法具有相对廉价、便捷等优点,已成为临床营养中营养评估和营养支持的重要方法。然而,我国间接能量测试仪(IC)的普及程度仍然很低,尤其对于中小型医院和大众健康领域。其原因主要在于:①测量仪器依赖于进口,价格昂贵,测量成本及器维护成本高;②测量相对耗时,不能满足我国医院病人服务高效率的需求;③测量需要专业操作人员。基于上述情况,本文开展如下研究:1、一种基于头罩式稀释法的间接能量测试方法的建立基于间接能量测试原理,本研究通过呼吸气体分析方法设计、气体采集与分析软硬件平台搭建,建立了具备自主知识产权的基于头罩式稀释法的间接能量测试方法。该方法采用了电子压力自动控制技术,通过反馈机制调节比例阀孔径,控制管路压力恒定,确保浓度测量的准确性;采用了稳定状态识别技术,不仅实时监测和显示被测试者呼吸交换参数VO_2和VCO_2的稳定程度指标(CV%),为操作者获取稳定状态下的代谢参数提供直观的参考,而且自动获取稳定状态区间的数据计算最终测量结果,降低了操作人员依赖性。2、间接能量测试系统的重复性与有效性研究重复性:通过38名受试者开展短期重复测量实验,用组内相关系数(ICC)、变异系数(CV%)、Bland-Altman分析的一致性范围(LoA)作为评价指标。结果显示,两次测量的VO_2和VCO_2的ICC分别为0.945和0.907, CV%分别为5.9%和8.3%,LoA分别为-21.0～29.1和-27.7～30.9,重复性较好且达到国际同类设备的水平。有效性采用两种方法:①体外模拟验证:模拟的呼吸交换参数与测量值的相关系数高(r=0.99,p0.001), LoA 范围窄(VO_2: -1.14～6.48,VCO_2:-0.87～8.11);②体内实验验证:采用本设备和同类设备(VO_2000)对38人进行测量结果比较。结果显示,二者相关系数高(VO_2: r=0.91,p0.001,VCO_2:r=0.89,p0.001),均值差异小(V02: 5.9%, VCO_2: 5.5%),一致性尚可(V02:-26.9～50.3,VCO_2: -24.8～43.2)。上述结果表明,自主研制的间接能量测试仪有效性较好。3、静息代谢率快速获取方法研究针对当前静息代谢率(RMR)测量耗时的现状,本研究重点探索了 RMR快速获取方法。首先,研究了当前RMR测量协议简化的可行性。提出1-min步长滑动时间窗法,通过32个受试者实验,观察分析RMR测量过程中人体状态稳定程度(CV%)和代谢率的动态变化过程。结果发现优化当前测量协议、缩短测量时间具有可行性。其次,研究了基于心率监测的RMR快速获取方法。基于心率与耗氧量、代谢率之间的关系,提出了一种基于心率监测的RMR快速获取方法。通过42名健康人群实验,验证了该快速获取方法的准确性。实验结果也表明,该方法不仅能够大幅减少平均测量时间(14分钟),而且能够根据被测试者个体状态进行判断,个性化测量时间。4、非肥胖健康成年人RMR最佳预测公式研究静息代谢率预测公式具有无成本、使用简单等特点,在缺乏IC的情况下能够发挥重要作用。RMR预测公式的适用与否在不同人群中存在差异。然而,针对我国非肥胖健康成年人群的RMR预测公式准确性研究仍然缺乏。因此,本研究应用所研制的间接能量测试仪,通过对46位该类人群RMR进行测量,评估14中常见预测公式的准确性。研究结果表明,该14个预测公式的准确性均不理想,IC法仍是评估该类人群RMR的首选方法。相对而言,Henry公式最适用,能够准确估算约70%该类人群的RMR,在缺乏IC的情况下,可将Henry公式作为IC的替代方法。未来的研究中,需要建立基于大样本、适用于我国特定人群的RMR预测公式。
[Abstract]:Malnutrition is a nutritional state that is harmful to the human body because of the imbalance of energy or nutrients. Malnutrition and the damage of vital organs in the inpatient and the high incidence of slow disease in the field of public health have become a huge risk and important public health problem for inpatient. Rate and metabolic substrates, to determine the nutritional requirements, and then carry out appropriate nutritional support, is an effective means to prevent malnutrition. In the metabolic measurement, indirect calorimetry has the advantages of relatively cheap and convenient, which has become an important method for nutritional assessment and nutritional support in clinical nutrition. However, our country's indirect energy testing instrument (IC) is popular. And the degree is still very low, especially for the small and medium hospitals and the public health areas. The main reasons are: (1) the measurement instruments are dependent on the import, the price is expensive, the cost of measurement and the maintenance cost are high, and the relative consumption of the measurement can not meet the high efficiency of the hospital patient service in our country; and the measurement needs professional operators. Based on the above situation The following research is carried out in this paper: 1, an indirect energy testing method based on head bell type dilution method is based on the principle of indirect energy test. This study is designed by breathing gas analysis method, and the software and hardware platform of gas acquisition and analysis is built, and the indirect energy test based on head bell type dilution method with independent intellectual property right is established. This method uses the electronic pressure automatic control technology, adjusts the aperture of the proportional valve through the feedback mechanism, controls the constant pressure of the pipeline to ensure the accuracy of the concentration measurement, and adopts the stable state recognition technology, which not only monitors and displays the stability index of the respiratory exchange parameters VO_2 and VCO_2 of the tested person in real time (CV%), and is obtained for the operator. An intuitive reference is provided for the metabolic parameters in the stable state, and the data of the stable state interval is automatically obtained to calculate the final results, and the operator dependence.2 is reduced. The repeatability and validity of the indirect energy test system is repeatable: the intra group correlation coefficient (ICC) is used by 38 subjects. The coefficient of variation (CV%) and the consistency range (LoA) of Bland-Altman analysis were used as evaluation indicators. The results showed that the ICC of VO_2 and VCO_2 for two measurements were 0.945 and 0.907 respectively, CV% was 5.9% and 8.3% respectively, and LoA was -21.0 to 29.1 and -27.7 to 30.9 respectively. The reproducibility was good and reached the level of international similar equipment. The effectiveness was used in two methods: 1 body External simulation verification: the correlation coefficient of the simulated respiratory exchange parameters and the measured values is high (r=0.99, p0.001), the LoA range is narrow (VO_2: -1.14 to 6.48, VCO_2:-0.87 ~ 8.11). 2. In vivo experiments verify that this equipment and similar equipment (VO_2000) are used to compare the measurement results to the 38 people. The results show that the correlation coefficient of the two is higher (VO_2: r=0.91, p0.001, VCO_2:r). =0.89, p0.001), the mean difference was small (V02: 5.9%, VCO_2: 5.5%), and the consistency was still available (V02:-26.9 to 50.3, VCO_2: -24.8 to 43.2). The results showed that the effectiveness of the self developed indirect energy testing instrument was good.3. The study on the rapid acquisition method of resting metabolic rate was focused on the status of the time-consuming metabolic rate (RMR) measurement in the rest of the rest period. RMR fast acquisition method. First, the feasibility of simplifying the current RMR measurement protocol is studied. A sliding time window method of 1-min step length is proposed. Through the experiment of 32 subjects, the dynamic change process of the state stability degree (CV%) and the metabolic rate in the RMR measurement process is observed and analyzed. The result shows that the current measurement protocol is optimized and the measurement time can be shortened. Secondly, the fast acquisition of RMR based on heart rate monitoring is studied. Based on the relationship between heart rate and oxygen consumption and metabolic rate, a fast RMR acquisition method based on heart rate monitoring is proposed. The accuracy of the fast acquisition method is verified by 42 healthy population experiments. The experimental results also show that this method can not only be greatly reduced. Less average time (14 minutes), and can be judged according to the individual state of the tested person, individual measurement time.4, the best prediction formula of RMR for non obese healthy adults, the prediction formula of resting metabolic rate has no cost, and the use of simple and other characteristics can play an important role in the application of the.RMR prediction formula under the absence of IC. There are differences in different populations. However, the accuracy of the RMR prediction formula for the non obese healthy adult population is still lacking. Therefore, the indirect energy testing instrument developed by this study is used to measure the accuracy of the common pretest formulas in 14 of the 46 groups of people. The results show that the 14 pretests have been made. The accuracy of the measurement formula is not ideal, IC method is still the first choice to evaluate the RMR of this group. Relative, the Henry formula is the most suitable and can accurately estimate the RMR of about 70% of the group. In the absence of IC, the Henry formula can be used as a substitute for IC. In the future study, it is necessary to establish a large sample based on the specific population of our country. The RMR prediction formula.

【学位授予单位】：中国科学技术大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：R459.3;TP274

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