School of Biomedical Engineering, Faculty of Engineering and Information Technology, University of Technology Sydney, Sydney, NSW, 2007, Australia.
Marcs Institute For Brain, Behaviour & Development, Western Sydney University, Sydney, NSW, 2751, Australia.
Med Biol Eng Comput. 2018 Dec;56(12):2337-2351. doi: 10.1007/s11517-018-1860-x. Epub 2018 Jun 28.
This paper applies a nonparametric modelling method with kernel-based regularization to estimate the carbon dioxide production during jogging exercises. The kernel selection and regularization strategies have been discussed; several commonly used kernels are compared regarding the goodness-of-fit, sensitivity, and stability. Based on that, the most appropriate kernel is then selected for the construction of the regularization term. Both the onset and offset of the jogging exercises are investigated. We compare the identified nonparametric models, which include both impulse response models and step response models for the two periods, as well as the relationship between oxygen consumption and carbon dioxide production. The result statistically indicates that the steady-state gain of the carbon dioxide production in the onset of exercise is bigger than that in the offset while the response time of both onset and offset are similar. Compared with oxygen consumption, the response speed of carbon dioxide production is slightly slower in both onset and offset period while its steady-state gains are similar for both periods. The effectiveness of the kernel-based method for the dynamic modelling of cardiorespiratory response to exercise is also well demonstrated. Graphical Abstract Comparison between VO and VCO during onset and offset of exercise.
本文应用基于核的正则化的非参数建模方法来估计慢跑过程中的二氧化碳生成量。讨论了核选择和正则化策略；比较了几种常用的核函数在拟合优度、灵敏度和稳定性方面的差异。在此基础上，选择最合适的核函数来构建正则化项。分别研究了慢跑运动的起始和结束阶段。我们比较了所识别的非参数模型，包括这两个阶段的脉冲响应模型和阶跃响应模型，以及耗氧量和二氧化碳生成量之间的关系。结果从统计学上表明，运动起始时二氧化碳生成量的稳态增益大于结束时的增益，而起始和结束时的响应时间相似。与耗氧量相比，在起始和结束阶段，二氧化碳生成量的响应速度稍慢，而两个阶段的稳态增益相似。核函数方法在运动心肺反应的动态建模中的有效性也得到了很好的证明。
