Saccomani M P, Cobelli C
Department of Electronics and Informatics, University of Padova, Italy.
IEEE Trans Biomed Eng. 1993 Aug;40(8):797-803. doi: 10.1109/10.238464.
To develop a model describing the structure and function of a metabolic system using data from an input-output experiment, it is useful to design a pilot tracer study first which contains a predicted maximal amount of information. Having postulated a physiologically reasonable model structure from the pilot data, two questions arise. First, are the model parameters a priori uniquely identifiable? That is, assuming an error-free model structure and data, can the parameters be uniquely identified from the information content of the pilot experiment? Second, if the model parameters are uniquely identifiable, is the pilot experiment a minimal one? That is, is the pilot experiment necessary and sufficient, in the sense of information content, among feasible experiments to guarantee a priori unique identifiability? The purpose of this paper is to determine a minimal input-output configuration for the a priori unique identifiability of a compartmental model describing the metabolism of leucine, an essential amino acid. The original pilot tracer experiment was a two-stage experiment consisting first of a two input-five output experiment followed by a single input-single output experiment. Here we show to guarantee a priori unique identifiability of the leucine model that the single input-single output experiment is not necessary, and that two of the outputs of the multi-input-multi-output experiment are not required.
为了利用输入-输出实验的数据开发一个描述代谢系统结构和功能的模型，首先设计一个先导示踪研究是很有用的，该研究应包含预测的最大信息量。根据先导数据假设了一个生理上合理的模型结构后，会出现两个问题。第一，模型参数在先验情况下是否唯一可识别？也就是说，假设模型结构和数据无误差，能否从先导实验的信息内容中唯一识别参数？第二，如果模型参数唯一可识别，先导实验是否是最小的？也就是说，从信息内容的角度来看，在可行的实验中，先导实验对于保证先验唯一可识别性是否必要且充分？本文的目的是确定一个最小的输入-输出配置，以实现对描述必需氨基酸亮氨酸代谢的房室模型的先验唯一可识别性。最初的先导示踪实验是一个两阶段实验，首先是一个两输入-五输出实验，然后是一个单输入-单输出实验。在此我们表明，为了保证亮氨酸模型的先验唯一可识别性，单输入-单输出实验不是必需的，并且多输入-多输出实验的两个输出是不需要的。
