Time domain analysis of oxygen uptake during pseudorandom binary sequence exercise tests.
Time domain analysis of oxygen uptake during pseudorandom binary sequence exercise tests.
复制标题
伪随机二元序列运动测试期间摄氧量的时域分析。
DOI：
10.1152/jappl.1991.71.4.1620
复制
发表时间：
1991
影响因子：
3.3
通讯作者：
G. Swanson
中科院分区：
文献类型：
--
作者：
R. Hughson;L. A. Cuervo;A. Patla;D. Winter;H. Xing;B. H. Dietrich;G. Swanson
伪随机二值序列（PRBS）运动测试包括根据计算机生成的模式在两种工作速率（WR）之间重复切换。本文提出了一种在时域上分析氧摄取（VO2）的方法。首先，将输入波噪比的自相关函数（ACF）识别为一个三角形脉冲，可以将其等效为波噪比的一个斜坡上升和一个斜坡下降。然后将输入（WR）和输出（VO2）的互相关函数当作对三角形脉冲的响应来处理。通过拟合双分量指数函数斜坡形式的线性和来分析互相关函数。通过两种不同的PRBS测试获得8名受试者的VO2反应，以及WR的阶跃变化。第一个PRBS测试包括15个单元，每个单元持续30秒。其ACF的基宽为60 s。斜坡增加-斜坡减少模型拟合整个响应范围内的数据。第二次PRBS测试有63个单元，每个单元持续5秒；因此其ACF基宽为10 s。再一次，斜坡模型完全适合。第二次PRBS检验的数据可以用双分量指数方程的脉冲形式拟合，但前30秒的拟合程度往往较差。步进试验和PRBS试验估算的VO2动力学时间常数无显著差异。PRBS测试可以在时域上进行分析，系统动力学指标反映了与WR阶跃变化相似的生理特性。
Pseudorandom binary sequence (PRBS) exercise tests involve repeated switching between two work rates (WR) according to a computer-generated pattern. This paper presents an approach to analysis of O2 uptake (VO2) in the time domain. First, the autocorrelation function (ACF) of the input WR was recognized to be a triangular-shaped pulse that can be taken to be equivalent to a ramp increase followed by a ramp decrease in WR. Then the cross-correlation function of the input (WR) and the output (VO2) was treated as if it were the response to a triangular-shaped pulse. The cross-correlation function was analyzed by fitting a linear summation of the ramp form of a two-component exponential function to this triangular pulse. VO2 responses of eight subjects were obtained from two different PRBS tests, as well as step changes in WR. The first PRBS test consisted of 15 units, each 30 s in duration. Its ACF had a base width of 60 s. The ramp increase-ramp decrease model fit the data throughout the range of response. The second PRBS test had 63 units, each 5 s in duration; thus its ACF base width was 10 s. Again, the ramp model fit adequately. The data from the second PRBS test could be fit by the impulse form of the two-component exponential equation, although the fit in the first 30 s tended to be poorer. The time constants of VO2 dynamics estimated from step and PRBS tests were not significantly different. PRBS tests can be analyzed in the time domain, and the indicators of system dynamics reflect physiological properties similar to those investigated during step changes in WR.