Expiratory Flow Limitation and Its Relation to Dyspnea and Lung Hyperinflation in Patients with Chronic Obstructive Pulmonary Disease: Analysis Using the Forced Expiratory Flow-Volume Curve and Critique

Background: Tidal expiratory flow limitation (tEFL) is defined as absence of increase in air flow during forced expiration compared to tidal breathing and is related to dyspnea at rest and minimal exertion in patients with chronic airflow limitation (CAL). Tidal EFL has not been expressed as a continuous variable (0% - 100%) in previous analyses. Objective: To relate the magnitude of tEFL to spirometric values and Modified Medical Research Council (MMRC) score and Asthma Control Test (ACT). Methods: Tidal EFL was computed as percent of the tidal volume (0% - 100%) spanned (intersected) by the forced expiratory-volume curve. Results: Of 353 patients screened, 192 (114 M, 78 F) patients (136 with COPD, 56 with asthma) had CAL. Overall characteristics: (mean ± SD) age 59 ± 11 years, BMI 28 ± 7, FVC (% pred) 85 ± 20, FEV1 (% pred) 66 ± 21, FEV1/FVC 55% ± 10%, RV (% pred) 147 ± 42. Tidal EFL in patients with tEFL was 53% ± 39%. Using univariate analysis, strongest correlations were between tEFL and FVC and between tEFL and RV in patients with BMI < 30 kg/m2. In patients with nonreversible CAL, tEFL was positively associated with increasing MMRC, negatively with spirometric measurements, and positively with RV/TLC. In asthmatics, ACT scores were higher in patients with mean BMI ≥ 28 kg/m2 (p < 0.00014) and RV/TLC values > 40% (p < 0.03). Conclusions: Dyspnea is strongly associated with tEFL and lung function, particularly in patients with nonreversible CAL. Air trapping and BMI contribute to tEFL.

New Interval Oscillation Criteria for Forced Second-order Half-linear Differential Equations

这份报纸讨论强迫的秒顺序的一个班一半线性的微分方程。由使用概括 Riccati 技术和平均技术，一些新间隔摆动标准被获得。

Second harmonic magnetoacoustic responses of magnetic nanoparticles in magnetoacoustic tomography with magnetic induction

Due to the unique magnetic, mechanical and thermal properties, magnetic nanoparticles(MNPs) have comprehensive applications as the contrast and therapeutic agents in biomedical imaging and magnetic hyperthermia. The linear and nonlinear magnetoacoustic responses determined by the magnetic properties of MNPs have attracted more and more attention in biomedical engineering. By considering the relaxation time of MNPs, we derive the formulae of second harmonic magnetoacoustic responses(2H-MARs) for a cylindrical MNP solution model based on the mechanical oscillations of MNPs in magnetoacoustic tomography with magnetic induction(MAT-MI). It is proved that only the second harmonic magnetoacoustic oscillations can be generated by MNPs under an alternating magnetic excitation. The acoustic pressure of the 2H-MAR is proportional to the square of the magnetic field intensity and exhibits a linear increase with the concentration of MNPs. Numerical simulations of the 2H-MAR are confirmed by the experimental measurements for various magnetic field intensities and solution concentrations using a laser vibrometer. The favorable results demonstrate the feasibility of the harmonic measurements without the fundamental interference of the electromagnetic excitation, and suggest a new harmonic imaging strategy of MAT-MI for MNPs with enhanced spatial resolution and improved signal-to-noise ratio in biomedical applications.

CALCULATION OF SECOND PHASE PARTICLE-GRAIN BOUNDARY INTERACTION RANGE

On the basis of the grain boundary equation by HeUman and corresponding analysis of Worner, this article deals with the interaction range between the second-phase particle （SPP） and grain boundary （GB） as viewed from the applicability of grain boundary equation. Also, a new expression describing the interaction range has been derived, which solves the problem in theory that the interaction range between SPP and GB can only be qualitatively analyzed previously. It is shown that given the interaction position between SPP and GB, the interaction range can be quantitatively determined by use of this expression.

Horizontal dynamic response of a large-diameter pipe pile considering the second-order effect of axial force

The second-order effect of axial force on horizontal vibrating characteristics of a large-diameter pipe pile is theoretically investigated.Governing equations of the pile-soil system are established based on elastodynamics.Threedimensional wave equations of soil are decoupled through differential transformation and variable separation.Consequently,expressions of soil displacements and horizontal resistances can be obtained.An analytical solution of the pile is derived based on continuity conditions between the pile and soil,subsequently from which expressions of the complex impedances are deduced.Analyses are carried out to examine the second-order effect of axial force on the horizontal vibrating behavior of the pipe pile.Some conclusions can be summarized as follows： stiffness and damping factors are decreased with the application of axial force on the pile head; distributions of the pile horizontal displacement and rotation angle are regenerated due to the second-order effect of the applied axial force; and redistributions of the bending moment and shearing force occur due to the second-order effect of the applied axial force.

SECOND-ORDER INTERACTION OF IRREGULAR WAVES WITH A TRUNCATED COLUMN

A complete semi-analytical solution is obtained for second-order diffraction of plane bichromatic waves by a fixed truncated circular column.The fluid domain is divided into interior and exterior regions.In the exterior region,the second-order velocity potential is expressed in terms of‘locked-wave’and‘free-wave’ components,both are solved using Fourier and eigenfunction expansions.The re- sulting‘locked wave’potential is expressed by one-dimensional Green's integrals with oscillating integrands.In order to increase computational efficiency,the far-field part of the integrals are carried out analytically.Solutions in both regions are matched on the interface by the potential and its normal derivative continuity conditions.Based on the present approach,the sum-and difference-frequency potentials are efficiently evaluated and are used to generate the quadratic transfer functions which correlates the incident wave spectrum with second-order forcing spectrum on the column.The sum-frequency QTFs for a TLP column are present,which are compared for some frequency pairs with those from a fully numerical procedure.Satisfactory agreement has been obtained.QTF spectra for a case study TLP column,generated using the semi-analytical solution are presented.Also given are the results for nonlinear wave field around the column.

Effects of Second-Order Sum-and Difference-Frequency Wave Forces on the Motion Response of a Tension-Leg Platform Considering the Set-down Motion

This paper presents a study on the motion response of a tension-leg platform(TLP) under first-and second-order wave forces, including the mean-drift force, difference and sum-frequency forces. The second-order wave force is calculated using the full-field quadratic transfer function(QTF). The coupled effect of the horizontal motions, such as surge, sway and yaw motions, and the set-down motion are taken into consideration by the nonlinear restoring matrix. The time-domain analysis with 50-yr random sea state is performed. A comparison of the results of different case studies is made to assess the influence of second-order wave force on the motions of the platform. The analysis shows that the second-order wave force has a major impact on motions of the TLP. The second-order difference-frequency wave force has an obvious influence on the low-frequency motions of surge and sway, and also will induce a large set-down motion which is an important part of heave motion. Besides, the second-order sum-frequency force will induce a set of high-frequency motions of roll and pitch. However, little influence of second-order wave force is found on the yaw motion.

Second-Order Potentials and Forces for Two-Dimensional Diffraction Problem of Finite Water Depth

-In this paper, an analytical solution in the outer region of finite water depth is derived for the second-order diffraction potential, which gives a clear physical meaning of the wave transmission and reflection characteristics in the far field. A numerical method-simple Green's function technique-for calculating the second-order diffraction potential in the inner region is also described. Numerical results are provided for the second-order wave forces on a semi-submerged cylinder. It is found that the contribution of second-order diffraction potential to second-order wave forces is important. The effect of water depth and submerged depth on the wave force is also discussed.

AN ANALYTICAL SOLUTION OF SECOND－ORDER WAVE FORCE ON A VERTICAL CIRCULAR CYLINDER

So far many investigations have been made on nonlinear wave diffraction problemfor a large-diameter vertical circular cylinder. However,there are still some problemsworthy to be further discussed. It includes that the second order radiation condition isnot very clear and the inhomogeneous term of second order free surface boundarycondition makes the calculation of second order wave force either not easier to beperformed accurately due to its slowly decaying with radial distance or toocomplicated for practical application. In this paper, the second order radiationcondition is posed of the circumferential Fourier components of second orderpotential, instead of the second order potential. It is found that the circumferenatialFourier cormponents of second order potential have to satisfy Sommerfeld radiationcondition. By means of the mathematical formulae derived in this paper, theinhomogeneous term of second order free surface boundary condition were simplifiedand then an exact expression of second order wave force was obtained, which issimpler in form and easier to be used in practical calculation. The calculation resultsagree well with some experimental data.

Second Law Analysis of the Optimal Fin by Minimum Entropy Generation

Based on the entropy generation concept of thermodynamics, this paper established a general theoretical model for the analysis of entropy generation to optimize fins, in which the minimum entropy generation was selected as the object to be studied. The irreversibility due to heat transfer and friction was taken into account so that the minimum entropy generation number has been analyzed with respect to second law of thermodynamics in the forced cross-flow. The optimum dimensions of cylinder pins were discussed. It’s found that the minimum entropy generation number depends on parameters related to the fluid and fin physical parameters. Variations of the minimum entropy generation number with different parameters were analyzed.

浮式风力机若干特征动力学问题综述

总结浮式风力机类型及其对应的特征动力学问题,针对浮式风力机气动荷载、水动荷载的计算方法以及结构动力学、控制动力学典型问题进行论述。讨论了气动—水动—结构—伺服耦合分析的难点,重点分析了二阶波浪力、畸形波等非线性波浪荷载、流荷载及涡激运动对浮式风力机特征动力响应的影响。阐述了浮式风力机动力学研究的试验方法、数值仿真方法、样机测试方法,并对模型试验技术的相似理论、气动模型的实现和难点以及数值仿真的频域方法、时域方法和分析工具进行了归纳对比。研究表明:浮式风力机多场、多体耦合动力分析机理及相关技术仍不成熟,气动荷载、高阶非线性波浪荷载耦合模型的建立是动力学问题研究的重点,数值仿真及模型试验是浮式风力机动力响应研究的主要方法,样机测试技术的积累将促进设计标准的完善及浮式风电的产业化发展。

Body mass index correlated with forced expiratory volume in 1 second/forced vital capacity in a population with a relatively low prevalence of obesity

Background Obesity is the most common metabolic disease in the world. However, the relationship between obesity and lung function is not fully understood. Although several longitudinal studies have shown that increases in body weight can lead to reductions in pulmonary function, whether this is the case with the Japanese population and whether high body mass index （BMI） status alone represents an appropriate predictor of obstructive lung dysfunction remains unclear.The purpose of present study was to estimate the effect of BMI on lung function measured by spirometry of Japanese patients in general clinics. We measured BMI and performed spirometry on screening patients who had consulted general clinics.Methods Subjects comprised 1231 patients ≥40 years of age （mean age （65.0±12.0） years, 525 men, 706 women） who had consulted clinics in Nagasaki Prefecture, Japan, for non-respiratory disease. BMI was calculated and lung function was measured by spirometry.Results BMI was found to be positively correlated with forced expiratory volume in 1 second （FEV1）/forced vital capacity （FVC） in men and with maximum mid-expiratory flow （MMF） in all subjects. Following adjustment for relevant factors, a significant positive correlation between BMI and FEV1/FVC was identified for all subjects. Comparison between subjects with normal BMI （18.5-25.0） and higher BMI （25.1-30.0） also demonstrated that FEV1/FVC and percentage of predicted maximum mid-expiratory flow （%MMF） were significantly higher in the latter subjects.Conclusions In a population without marked respiratory disease, higher BMI subjects showed less obstructive pulmonary dysfunction compared to normal BMI subjects. High BMI status alone may be inappropriate as a predictor of obstructive lung dysfunction, particularly in populations with a low prevalence of obesity.

血清人软骨糖蛋白-39对慢性阻塞性肺疾病急性加重的诊断价值

目的探讨血清人软骨糖蛋白-39(YKL-40)对于慢性阻塞性肺疾病(COPD)急性加重(AECOPD)的诊断价值。方法纳入2018年9月至2019年6月在河北北方学院附属第一医院住院AECOPD病人85例及同期70例COPD稳定期病人作为对照组,受试者均检测血清YKL-40、降钙素原(PCT)及C反应蛋白(CRP)水平,收集各受试者在院检测的肺功能、血气分析结果。观察各指标在不同的AECOPD临床分级的变化以及YKL-40与相关临床参数的关系。结果两组YKL-40(58.03±12.78)μg/L比(38.69±8.72)μg/L、PCT(7.54±2.71)μg/L比(3.72±1.79)μg/L、CRP(99.29±34.98)mg/L比(52.91±27.77)mg/L比较均差异有统计学意义。随着病人病情加重,AECOPDⅠ、Ⅱ、Ⅲ级血清YKL-40水平逐渐升高(49.23±11.26)μg/L、(56.70±10.38)μg/L、(67.93±10.32)μg/L,各组间比较均差异有统计学意义(均P<0.05)。YKL-40与PCT、CRP、动脉血二氧化碳分压(PaCO_(2))呈正相关,但与预测的第一秒用力呼气容积(FEV_(1))、第一秒用力呼气容积占预计值的百分比(FEV_(1)%)、第一秒用力呼气量占用力肺活量百分率(FEV_(1)/FVC)和动脉血氧分压(PaO2)呈负相关(P<0.05)。结论AECOPD病人血清YKL-40水平随病情加重而升高,升高程度与病情严重程度相关。

FEV1回归模型在肺通气检查禁忌人群中的应用

目的建立肺通气检查禁忌人群第1秒用力呼吸容积(FEV1)预计式,以推测此人群FEV1预计值。方法本实验分为回顾性研究及前瞻性研究。回顾性收集病例资料1,273例作为建模实验组;前瞻性收集验证组375例。收集基本资料、肺功能测定FEV1值及强迫振荡技术(FOT)测定呼吸阻力R5值。采用Pearson相关分析探究实验组各因素与FEV1相关性。多元线性回归分析,建立预计方程。配对t检验验证组FEV1真实值和预计值差异。结果FEV1与体质量无模型相关关系,与身高呈正相关关系,年龄呈负相关关系,R5呈负相关关系(P<0.05)。建模与验证:纳入身高、年龄和R5,实际值与预计值在验证样本中无统计学差异(P>0.05),且验证样本两值相关性好。结论本研究人群中FEV1真实值与预计值无统计学差异,模型有较好的准确性,可应用于临床诊疗。

膈肌厚度比在肌间沟臂丛神经阻滞致膈肌麻痹中的诊断价值

目的 评价膈肌厚度比(DTI)在肌间沟臂丛神经阻滞导致膈肌麻痹中的诊断价值。方法 选择择期行肱骨中段、桡骨骨折内固定或取内固定术的患者51例,男27例,女24例,年龄18~64岁,BMI 18~30 kg/m^(2),ASAⅠ或Ⅱ级。所有患者采用0.5%罗哌卡因20 ml在超声引导下行肌间沟臂丛神经阻滞。以用力呼吸时膈肌移动度(DE)作为标准将患者分为两组:麻痹组(n=11,DE≥25%)和非麻痹组(n=40,DE<25%)。记录阻滞前、阻滞后15 min阻滞侧DE、吸气末膈肌厚度(DTei)、呼气末膈肌厚度(DTee)、用力肺活量(FVC)、第一秒用力呼气容积(FEV_(1))、SpO_(2),感觉、运动阻滞时间和恢复时间,并记录芬太尼用量,给药24 h内恶心、呕吐、声音嘶哑、头痛、霍纳综合征、低血压、呼吸困难等不良反应发生情况。绘制受试者工作特征(ROC)曲线,分析DTI、FVC下降幅度对诊断臂丛神经阻滞所致急性膈肌麻痹的曲线下面积(AUC)和95%可信区间(CI)、界值、敏感性和特异性。结果 两组阻滞前DE、DTI、FVC、FEV_(1)、SpO_(2)差异无统计学意义。与非麻痹组比较,阻滞后15 min麻痹组DE、DTI明显减小(P<0.05),DE下降幅度、FVC下降幅度明显增大(P<0.05),呼吸困难发生率明显升高(P<0.05)。两组芬太尼用量及其他不良反应差异无统计学意义。阻滞后DTI诊断急性膈肌麻痹的AUC为0.973(95%CI 0.927~1.000),界值1.2,敏感性100%,特异性95%。阻滞后FVC下降幅度诊断急性膈肌麻痹的AUC为0.697(95%CI 0.534~0.860),界值10%,敏感性100%,特异性38%。结论 与用力肺活量比较,膈肌厚度比对诊断臂丛神经阻滞所致急性膈肌麻痹有较好的诊断价值,且不需要进行术前基线值测量。

基于参数自适应的RSSD-CYCBD及在轴承外圈故障特征提取中的应用

针对滚动轴承工作环境复杂、故障特征信号易被高强度噪声掩盖的问题,提出了基于参数自适应的共振稀疏分解(RSSD)和最大二阶循环平稳盲解卷积(CYCBD)的滚动轴承故障诊断方法。首先,利用人工大猩猩部队优化算法(GTO),结合相关系数与相关峭度的融合指标,自适应选择RSSD分解参数,得到了仿真信号的最优低共振分量;然后,利用GTO结合包络熵,自适应选择CYCBD的循环频率和滤波器长度,对最优低共振分量进行了解卷积运算,从包络谱中获得了信号的故障特征频率;最后,利用美国凯斯西储大学试验台和MFS-MG机械故障综合模拟试验台数据,综合验证了该方法的有效性,并将试验结果与RSSD-MCKD方法的结果进行了对比。研究结果表明,该方法能够准确地得到仿真信号的故障频率为20 Hz、美国凯斯西储大学试验台近似故障频率为107.5 Hz、MFS-MG试验台近似故障频率为87.6 Hz。自适应RSSD-CYCBD方法能够有效地识别出故障特征频率及其倍频,实现滚动轴承故障诊断的目的。

呼吸机相关性肺炎患者出院后生存质量及与特征变量的相关性分析

目的研究呼吸机相关性肺炎(ventilator-associated pneumonia,VAP)患者出院后生存质量情况,并对特征变量进行相关性分析。方法选取2019年11月至2022年11月诊治的100例VAP作为研究对象,收集患者临床特征、世界卫生组织生存质量测定量表简表(WHOQOL-BREF)评分;分析患者生存质量现状,比较不同临床、肺功能特征患者生存质量;分析降钙素原(PCT)、白细胞计数(WBC)、C反应蛋白(CRP)与肺功能指标、WHOQOL-BREF评分的相关性;采用多元线性回归分析VAP患者生存质量的影响因素;采用受试者工作特征(ROC)曲线分析PCT、WBC、CRP联合预测患者生存质量的价值。结果100例VAP患者WHOQOL-BREF量表生理、心理、社会关系维度评分及总评分均低于常模评分(P<0.01),且低生存质量患者39例,占比为39.00%;年龄大、心功能不全及PCT、WBC、CRP升高人群低生存质量者占比比较差异有统计学意义(P<0.01);用力肺活量(FVC)异常人群低生存质量患者占比高于正常人群(P<0.01);第1秒用力呼气量(FEV1)/FVC异常人群低生存质量患者占比高于正常人群(P<0.01);VAP患者PCT、WBC、CRP与FVC、FEV1/FVC、WHOQOL-BREF评分呈负相关(P均<0.05);多元线性回归分析显示,年龄大、心功能不全及PCT、WBC、CRP升高是VAP患者生存质量的影响因素(P<0.01);ROC曲线显示,PCT、WBC联合CRP预测VAP患者生存质量的曲线下面积(AUC)为0.911,大于PCT、WBC、CRP单一预测的AUC(P<0.01)。结果VAP患者出院后低生存质量者占比较高,年龄大、心功能不全及PCT、WBC、CRP升高是VAP患者生存质量的影响因素;且PCT、WBC、CRP异常水平与肺功能、生存质量呈负相关,其联合预测患者生存质量具有一定参考价值。

膈肌功能参数与慢性阻塞性肺疾病患者肺功能指标的相关性及其评估病情严重程度的价值

目的探究膈肌功能参数与慢性阻塞性肺疾病(COPD)患者肺功能指标的相关性及其评估病情严重程度的价值。方法选取2021年9月—2023年11月收治的100例COPD为研究对象,纳入COPD组;再依据COPD分级标准分为轻-中度组(COPDⅠ~Ⅱ级)、重度组(COPDⅢ级及以上)。同时招募与COPD组年龄、性别相匹配的健康志愿者40例作为对照组。均进行膈肌超声检查[用力呼吸(TLC)、平静呼吸(FRC)时相膈肌移动度及膈肌厚度]以及肺功能检查[第1秒用力呼气容积占预计值百分比(FEV1%pred)、用力肺活量占预计值百分比(FVC%pred)、FEV1/FVC],比较各组间膈肌功能参数差异,分析膈肌功能参数与肺功能指标的相关性及评估病情严重程度的价值。结果COPD组改良版英国医学研究会呼吸困难量表评分高于对照组,FEV1%pred、FVC%pred、FEV1/FVC均低于对照组(P<0.05)。TLC、TLC-FRC时相的膈肌移动度和膈肌厚度,重度组低于轻-中度组低于对照组(P<0.05);FRC时相膈肌移动度,重度组和轻-中度组均高于对照组(P<0.05),但重度组与轻-中度组比较差异无统计学意义(P>0.05)。膈肌移动度与COPD患者FEV1/FVC、FEV1%pred、FVC%pred呈正相关(P<0.01)。TLC时相膈肌厚度与FEV1/FVC、FEV1%pred呈正相关(P<0.05)。TLC时相膈肌移动度及膈肌厚度评估COPD病情严重程度的曲线下面积分别为0.821及0.673。结论COPD患者超声膈肌功能参数与肺功能指标具有显著相关性,超声检测膈肌功能参数对辅助评估COPD病情严重程度具有重要参考价值。

超声评估慢性阻塞性肺疾病患者膈肌功能与肺功能关联性研究

目的 探讨超声评估慢性阻塞性肺疾病(COPD)患者膈肌功能与肺功能相关性。方法 选取2022年1月—2023年3月收治的100例COPD为研究组,选取同期100名体检健康者为对照组。2组均接受肺功能和超声检查,比较2组肺功能指标以及对照组与不同COPD分级患者膈肌移动度,分析COPD患者膈肌功能与肺功能相关性。结果 研究组改良医学研究委员会呼吸困难指数(mMRC)评分和残气量(RV)/肺总容量(TLC)较对照组高,而第1秒用力呼气容积(FEV1)/用力肺活量(FVC)、FVC占预计值百分比(FVC%pred)和FEV1占预计值百分比(FEV1%pred)则较对照组低(P<0.05)。重度组平静呼吸时膈肌移动度(FRC)较中度组、轻度组、对照组高,而用力呼吸时膈肌移动度(DE)、不同呼吸时相膈肌移动度差值(DE-FRC)则较中度组、轻度组、对照组低(P<0.05);中度组FRC较对照组高,而DE、DE-FRC则较轻度组和对照组低(P<0.05);轻度组DE-FRC较对照组低(P<0.05)。COPD患者膈肌功能与FEV1%pred、FVC%pred、FEV1/FVC和DE-FRC均呈正相关(r=0.595、0.436、0.637、0.576,P<0.05),而与mMRC评分、RV/TLC呈负相关(r=-0.613、-0.348,P<0.05)。结论 COPD患者膈肌功能与肺功能存在明显相关性,可通过超声评估膈肌形态了解其功能,进而为疾病诊断和治疗提供参考。

睡眠时长和睡眠质量对老年慢性阻塞性肺疾病预后的影响

目的:探究睡眠时长和睡眠质量对老年慢性阻塞性肺疾病(COPD)预后的影响。方法:选取2019年5月至2023年5月福建省宁德市霞浦县三沙中心卫生院普通内科收治的老年COPD稳定期患者86例作为研究对象。随访6个月,依据急性加重情况分为急性加重组(急性加重发作次数≥1次)和稳定组。比较急性加重组和稳定组患者的临床资料。Logistic回归分析影响老年COPD急性加重的相关因素。制作受试者工作特征曲线(ROC),以曲线下面积(AUC)分析睡眠时长和睡眠质量对老年COPD急性加重的预测效能。结果:患者入院治疗后随访6个月,发生急性加重患者21例(24.42%)。急性加重组与稳定组性别、年龄、体质量指数(BMI)、吸烟、饮酒、病程、第1秒用力呼气容积(FEV1)、用力肺活量(FVC)比较差异均无统计学意义(均P>0.05);急性加重组FEV1/FVC、睡眠时长均低于稳定组,睡眠质量评分高于稳定组(P<0.05)。多因素分析结果显示,FEV1/FVC、睡眠时长、睡眠质量均为影响老年COPD急性加重的独立因素(OR=3.466、2.147、2.251,P<0.05)。ROC分析显示,睡眠时长、睡眠质量对老年COPD急性加重的特异度为96.60%,高于单独睡眠时长、睡眠质量,且睡眠时长、睡眠质量二者联合预测老年COPD急性加重的AUC为0.911,高于其单独预测的AUC(Z=2.675,P=0.039;Z=2.986,P=0.032)。结论:睡眠时长、睡眠质量与老年COPD急性加重均存在一定的相关性,且睡眠时长联合睡眠质量对老年COPD急性加重进行预测的效能较高,可作为临床评估老年COPD急性加重的重要参考指标。