Pitot-tube flowmeter for quantification of airflow during sleep
Pitot-tube flowmeter for quantification of airflow during sleep
复制标题
DOI：
10.1088/0967-3334/32/2/006
复制
发表时间：
2011-02-01
影响因子：
3.2
通讯作者：
Schneider, H.
中科院分区：
文献类型：
--
作者：
Kirkness, J. P.;Verma, M.;Schneider, H.
由于必须佩戴的设备的尺寸、重量、笨重和不适，金标准呼吸速度描记器通常不用于在夜间多导睡眠图中量化气流。为了克服这些在常规睡眠研究中排除使用呼吸速度描记器的缺陷，我们的小组开发了一种用于睡眠期间的轻质、低死腔的“皮托管流量计”（基于皮托管原理）。我们旨在通过与呼吸速度描记器进行头对头比较，检查流量计的特性并验证其在多导睡眠描记术期间用于量化气流和检测呼吸不足。四个实验范例被用来确定皮托管流量计的技术性能特点和临床实用性的头对头比较与呼吸速度描记器。在每项研究（1-4）中，皮托管流量计在静态流量（流量发生器内联或在面部模型上）或动态流量（受试者通过聚酯面部模型或鼻罩呼吸）条件下与呼吸速度描记器串联。皮托管流量计的技术特性表明，（1）在10至50 L min（1）的气流速率下，气流阻力范围为0.065 +/-0.002至0.279 +/- 0.004 cm H2O L-1 s（-1）。(2)在聚酯面部模型上，由皮托管流量计输出电压测量的气流与校准的呼吸速度描记器信号a之间存在线性关系（β（1）= 1.08 V L-1 s（-1）; β（0）= 2.45 V）。临床相关性能特征（呼吸不足检测）显示：（3）当皮托管流量计通过面罩连接到人脸模型时，检测峰-峰气流幅度降低50%的灵敏度和特异性均为99.2%。当在睡眠中的人类受试者中进行测试时，（4）皮托管流量计信号显示出94.5%的灵敏度和91.5%的特异性，用于检测呼吸速度描记器测量的气流中50%的峰到峰减少。我们的数据验证了皮托管流量计的量化气流和检测呼吸减少在多导睡眠研究。我们推测，量化睡眠期间的气流可以区分与睡眠呼吸障碍相关的表型特征。
The gold-standard pneumotachograph is not routinely used to quantify airflow during overnight polysomnography due to the size, weight, bulkiness and discomfort of the equipment that must be worn. To overcome these deficiencies that have precluded the use of a pneumotachograph in routine sleep studies, our group developed a lightweight, low dead space 'pitot flowmeter' (based on pitot-tube principle) for use during sleep. We aimed to examine the characteristics and validate the flowmeter for quantifying airflow and detecting hypopneas during polysomnography by performing a head-to-head comparison with a pneumotachograph. Four experimental paradigms were utilized to determine the technical performance characteristics and the clinical usefulness of the pitot flowmeter in a head-to-head comparison with a pneumotachograph. In each study (1-4), the pitot flowmeter was connected in series with a pneumotachograph under either static flow (flow generator inline or on a face model) or dynamic flow (subject breathing via a polyester face model or on a nasal mask) conditions. The technical characteristics of the pitot flowmeter showed that, (1) the airflow resistance ranged from 0.065 +/- 0.002 to 0.279 +/- 0.004 cm H2O L-1 s(-1) over the airflow rates of 10 to 50 L min (1). (2) On the polyester face model there was a linear relationship between airflow as measured by the pitot flowmeter output voltage and the calibrated pneumtachograph signal a (beta(1) = 1.08 V L-1 s(-1); beta(0) = 2.45 V). The clinically relevant performance characteristics (hypopnea detection) showed that (3) when the pitot flowmeter was connected via a mask to the human face model, both the sensitivity and specificity for detecting a 50% decrease in peak-to-peak airflow amplitude was 99.2%. When tested in sleeping human subjects, (4) the pitot flowmeter signal displayed 94.5% sensitivity and 91.5% specificity for the detection of 50% peak-to-peak reductions in pneumotachograph-measured airflow. Our data validate the pitot flowmeter for quantification of airflow and detecting breathing reduction during polysomnographic sleep studies. We speculate that quantifying airflow during sleep can differentiate phenotypic traits related to sleep disordered breathing.