D-value estimation of dynamic spectrum based on the statistical methods

To realize the noninvasive concentration detection of blood components and improve the drawbacks existing in the time-domain single-trial estimation method of "dynamic spectrum" (DS), the D-value estimation method based on the statistical properties was proposed. We extracted the absolute difference between two corresponding values of each wavelength to make up the DS, selected the valid DSs from the DSs of different times by statistic method, and the valid DSs were superimposed and averaged as the final output of the DS. Data collected from 48 volunteers were processed by the D-value estimation and the single-trial estimation, respectively; and then the comparison was carried out between the two methods. Compared with the single-trial estimation, the valid DSs extracted by the D-value estimation were slightly better in denoising; And the average number of the remained valid DSs is improved from 48 to 130; the average of mean square error among the valid DSs is improved from 0.39 to 0.006; the speed of data processing is increased by nearly 20 times. The new method can significantly improve the quality of the extraction of DS.