Chadha T S, Watson H, Birch S, Jenouri G A, Schneider A W, Cohn M A, Sackner M A
Am Rev Respir Dis. 1982 Jun;125(6):644-9. doi: 10.1164/arrd.1982.125.6.644.
We devised a new calibration procedure [least squares method (LSQ)] for respiratory inductive plethysmography (RIP) and compared it with our previously reported simultaneous equation method (SEQ) of analyzing data in 2 body positions and with the method of Stagg and associates using the analysis of individual breaths in a single body position. The values from RIP were compared with simultaneous spirometry (SP) in 20 normal subjects placed in the standing (STD), supine (SUP), sitting, prone, semi-recumbent, right lateral decubitus, and left lateral decubitus postures. The LSQ gave the most accurate results followed closely by SEQ. In addition, LSQ was compared with the isovolume angle maneuver (ISV) calibration procedure in supine (ISV-SUP) and standing (ISV-STD) postures. Each of the 10 normal subjects breathed at tidal volumes of 250, 750, and 1,250 ml in the SUP and STD postures. Of the values obtained by the LSQ method, 93% were within +/- 10% of SP in SUP and STD positions. Without a change in the posture in which the calibration was made, 83% of values with ISV-SUP and 90% of values with ISV-STD were within +/- 10% of SP. When body position was changed, 65% of the values obtained with ISV-SUP and 38% of the values obtained with ISV-STD were within +/- 10% of SP. With the LSQ, 45% of isovolume angles in SUP and STD position were within 45 +/- 3 degrees; 40% of isovolume angles with ISV-SUP and 60% with ISV-STD were within 45 +/- 3 degrees when body position was changed from position calibrated. In estimating fractional contribution of rib cage and abdominal compartments. LSQ was comparable to ISV in the standing posture but generally gave lesser values for the rib cage contribution in the supine posture than ISV. The optimal calibration procedure for respiratory inductive plethysmography in terms of accuracy and ease of subject performance is the least squares calibration procedure.
我们为呼吸感应体积描记法（RIP）设计了一种新的校准程序[最小二乘法（LSQ）]，并将其与我们之前报道的用于分析两个身体姿势数据的联立方程法（SEQ）以及Stagg及其同事使用的在单个身体姿势下分析单个呼吸的方法进行了比较。将20名正常受试者分别置于站立（STD）、仰卧（SUP）、坐姿、俯卧、半卧位、右侧卧位和左侧卧位时，RIP测得的值与同步肺活量测定法（SP）的结果进行了比较。LSQ得出的结果最准确，SEQ紧随其后。此外，还将LSQ与仰卧位（ISV-SUP）和站立位（ISV-STD）的等容角动作（ISV）校准程序进行了比较。10名正常受试者分别在仰卧位和站立位以250、750和1250 ml的潮气量呼吸。在仰卧位和站立位，LSQ法测得的值中93%在SP值的±10%范围内。在校准姿势不变的情况下，ISV-SUP测得值的83%和ISV-STD测得值的90%在SP值的±10%范围内。当身体姿势改变时，ISV-SUP测得值的65%和ISV-STD测得值的38%在SP值的±10%范围内。采用LSQ时，仰卧位和站立位45%的等容角在45±3度范围内；当身体姿势从校准姿势改变时，ISV-SUP测得的等容角中有40%、ISV-STD测得的等容角中有60%在45±3度范围内。在估计胸廓和腹部腔室的分数贡献时，LSQ在站立姿势下与ISV相当，但在仰卧姿势下胸廓贡献的值通常比ISV小。就准确性和受试者操作的简便性而言，呼吸感应体积描记法最佳的校准程序是最小二乘校准程序。
