3.6. Selection of the spread constants
The effect of the spread RMSEC, RMSEP Da value was investigated and the results are shown in Fig. 5. As can be seen, the RMSEC, RMSEP and Da value become stable when the spread constant of RBFNN models for monitoring glucose and pH were larger than 0.44 and 0.13 respectively. The optimum spread constants of RBFNN models for monitoring glucose and pH with the highest Da values were 0.53000 and 0.13000, respectively.