[Application of EMD algorithm to the dynamic spectrum non-invasive measurement of hemoglobin].

Empirical mode decomposition (EMD) algorithm combined with the theory of dynamic spectrum extraction at frequency domain was applied to the noninvasive measurement of hemoglobin concentration. Fifty seven cases' photoplethysmography was collected in the range of 636.98-1086.

[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.

[Application of EMD and SPA algorithm in the detection of benzoyl peroxide addition in flour by spectroscopy].

In order to improve the accuracy of spectroscopy analysis and reduce the modeling wavelength numbers, empirical mode decomposition (EMD) and successive projections algorithm (SPA) were applied together in the measurement of benzoyl peroxide (BPO) additive amount in flour by near infrared spectroscopy. Spectra of flour samples into which BPO were added were collected. Firstly, EMD was implemented to eliminate the noise of original spectra, and then SPA was employed to select the characteristic wavelengths.

[Noninvasive measurement of the human RBC concentration based on BP NN model].

In the present article, the BP neural network's arithmetic model is applied to the noninvasive detection of the concentration of the red blood cell of human body. Due to the use of BP neural network in the modeling and analysis of the dynamic spectrum data and the actual measured value of the red blood cell, the authors get a better result which refers to that the output value tracks the expected result very well. The related coefficient R can reach 0.

[The analysis for improving the SNR of blood components noninvasive measurement with DS method].

In order to increase the accuracy of blood components measurement and enhance the stability of prediction model, the quantitative signal-noise-ratio (SNR) analysis of measuring instruments based on dynamic spectrum (DS) and preprocessing method was conducted. The SNR of DS is increased after adding boxcar integrator, decreasing wavelength revolution, balancing the DS's SNR and excluding gross errors in preprocessing according to experiment results. Two volunteers were tested continuously for many times using the DS data acquiring system.

[The effects of signal to noise ratio of instrument and number of wavelengths on the accuracy of spectral analysis].

In order to study the influence of the two factors, the signal to noise ratio (SNR) of instrument and number of wavelengths, on the accuracy of quantitative analysis in spectral modeling analysis, the influences of different SNRs, the number of wavelengths participating in partial least square regression, and multi-wavelength modeling in different SNR bands were taken into account. The relationships between these factors and quantitative analysis accuracy were explored by modeling analysis experiments. The results show that the analysis accuracy is directly related to the SNR of instrument.

[Improving component analysis ability of the complex mixed solutions by multi-dimensional diffuse transmittance spectrometry].

The multi-dimensional diffuse transmittance spectrums were collected by the traditional near-infrared transmittance method combined with a scanning device, and then used for component analysis of the complex mixed solution. A xenon light, an electric control translation stage and a spectrometer were gathered to set up a device; Intralipid-20%, India-ink and C6H12O6 were used to prepare 225 kinds of complex mixed solutions; the diffuse transmittance spectrums were measured at 20 points off the transmission center distributed from 0-5 mm (interval 0.25 mm); the single and multi-point diffuse transmittance spectrums were analyzed by partial least squares regression for modeling and prediction.

[Noninvasive measurement of serum total protein content by near-infrared reflection spectra with tongue inspection].

The technology of tongue near-infrared reflectance spectra was used for human serum total protein (TP) content of noninvasive testing for the first time. Reflectance spectrum on the tongue tips of 58 volunteers was collected, and the biochemical values of serum total protein were recorded at the same time. The samples were separated into two parts: training set and prediction set.

[Effect of different distribution of components concentration on the accuracy of quantitative spectral analysis].

In order to discuss the effect of different distribution of components concentration on the accuracy of quantitative spectral analysis, according to the Lambert-Beer law, ideal absorption spectra of samples with three components were established. Gaussian noise was added to the spectra. Correction and prediction models were built by partial least squares regression to reflect the unequal modeling and prediction results between different distributions of components.

[A modulation method to improve the signal-to-noise ratio of internal virtual hyperspectrum of body surface].

Virtual internal hyperspectrum of body surface which can express and properly mix the information of skin's composition and structure was expected to apply in the human disease quick-diagnosis, but the weak detected signal was easily impacted by ambient light and dark current from the instrument, so square wave modulated by chopper disk was proposed to resolve this issue. First, we built the experiment platform, and selected both laser and bromine tungsten lamp as the light source, then compared the virtual hyperspectrum of non-modulated and modulated light on human arm in the environment with artificial interference, and demodulated the modulated signal by FFT method. The experiment result showed that modulation method could effectively eliminate the impact brought by environmental light and dark current and improve the signal to noise ratio (SNR), suggesting a new approach to detect human's weak optical signals.

[The concentration resolution of complex liquid spectrometry analysis and the effect of concentration distribution].

In order to ensure the feasibility of complex liquid spectroscopy analysis, to analyze the accuracy gain of modeling by multi-wavelength, and to determine the appropriate distribution of concentration to obtain the high quality and universal quantitative analysis model, the precision of the detection of composition concentration by spectral analysis is illustrated through a error analysis which takes into account the following three contributions: spectral instrument noise, multi-wavelength modeling and the distribution of composition concentration. By concentration resolution analysis, the concentration resolution can be achieved when the spectrometer noise is available, but also the theoretical basis is provided to select a suitable spectrometer to meet the resolution requirement of quantitative analysis. Over-sampling technique indicates that the precision improvement by modeling with multi-wavelength can obtain higher concentration detection sensitivity.

[Feasibility of composition analysis of complex mixed solution by hyperspectral technique].

The complex mixed solution is a common material form in all walks of life. It was difficult to achieve the desired results if the complex mixed solution was detected by the traditional spectral analysis method. The hyperspectral technology was taken to detect the complex mixed solution to improve the signal to noise ratio of the spectrum by utilizing the absorbing and scattering characteristics of the analytes at the same time.

[Study on detection of changes in tissue structure and composition by using virtual internal hyper-spectrum of body surface].

Purposed to achieve the detection of changes in tissue structure and composition simultaneously by virtual internal hyper-spectrum of body surface (VIHBS), we designed the VIHBS system containing modulated light, translation stage device for data acquisition and spectrometer. In the present study, pork meat as the experimental subject was equally divided into three pieces. One piece was used for a control study, and the others were separately embedded with red filter and injected into highly scattering intralipid to imitate the changes in tissue structure and composition.

[Component analysis of complex mixed solution based on multidimensional diffuse reflectance spectroscopy].

In the present paper, the authors proposed a method for component analysis of complex mixed solutions based on multidimensional diffuse reflectance spectroscopy by analyzing the information carried by spectrum signals from various optical properties of various components of the analyte. The experiment instrument was designed with supercontinuum laser source, the motorized precision translation stage and the spectrometer. The Intralipid-20% was taken as an analyte, and was diluted over a range of 1%-20% in distilled water.

[Equalization of whole-band signal's SNR in the blood components noninvasive measurement].

To fully extend the category of blood components that can be noninvasively measured by dynamic spectrum (DS) method and to increase its measuring precision, an overall consideration of light source, tissue absorption and sensor's sensitivity was made. Compensating the light source and adding the telecentric lens not only expand the spectral effective detecting range, but also balance the signal-to-noise ratio (SNR) of the photoelectric pulse in the whole band equalization. The integral SNR of DS signal was increased and the measurement bandwidth was expanded.

Relaxation creep rupture of heterogeneous material under constant strain.

We focus on a system consisting of an elastic part and a damageable part in series, to study the relaxation creep rupture of a heterogeneous system subjected to a uniaxial constant strain applied instantaneously. The viscoelastic behavior of the damageable part is modeled by a fiber bundle model consisting of Kelvin-Voigt elements and global load sharing is assumed for the redistribution of load following fiber breaking in the damageable part. Analytical and numerical calculations show that the global relaxation creep rupture appears if the elastic energy stored in the elastic part exceeded the fracture energy of the damageable part.

[Validation of feasibility of virtual hyperspectral technology].

To verify the virtual hyperspectral technology for acquiring the internal composition and structure information, the virtual hyperspectral system, which took apples as the test materials, was built. First, we detected the virtual hyperspectral system of the normal apples and ill apples. Then, the virtual hyperspectral of apple slices and apple slices with a piece of red optical filter embedded was detected.

[Hyperspectral acquisition system for tongue inspection based on X-Y scanning galvanometer].

Hyperspectral was used for tongue inspection in the present work to resolve the problem that information of current research for tongue inspection was inadequate. A hyperspectral acquisition system based on X-Y scanning galvanometer was also proposed due to the high cost of the current hyperspectral apparatus. An experiment was made to test the ability of this system.

[Detection of benzoyl peroxide in wheat flour by NIR diffuse reflectance spectroscopy technique].

Adding benzoyl peroxide (BPO) into wheat flour was prohibited by the relevant government departments since May 1, 2011. And it is of great importance to detect BPO additive amount in wheat flour quickly and accurately. Part of BPO which was added into wheat flour will be deoxidized into benzoic acid, and this make it complex to detect the original BPO additive amount.

[Monte Carlo simulation of the determination of complex mixed solution with hyperspectral technique].

In order to overcome the defects of overlapping spectrum and low signal-to-noise ratio in the analysis of the complex mixed solution with the traditional spectral method, the authors introduce hyperspectral technique to the analysis of complex mixed solution in the present article. The hyperspectral technique can use the information of the analytes carried by multi-mode photons to analyze the solution. Compared with the traditional methods that only use the absorption characteristics for analysis, the hyperspectral technique also use the space information to increase the spectral signal-to-noise ratio and to improve the modeling accuracy and reliability.

[Research on the measurement of urinary albumin by visible-near infrared spectroscopy].

The urinary albumin (UMALB) is the most reliable diagnostic indicator of renal injury in clinical. Attempting to realize the rapid and free reagent measurement of UMALB, the visible-near infrared multiple optical path length spectra of 207 urine samples were collected. By the nonlinear characteristics of multiple optical path length spectra, more information about the component of sample contents can be obtained.

[Single-trial estimation of dynamic spectrum].

To improve the efficiency and accuracy of the dynamic spectrum data processing, the method of single-trial estimation was adopted. First, the rising edge of the whole band PPG was extracted, which was calculated by averaging superimposed collected photoelectric plethysmography (PPG) at all wavelengths as a template per single pulse; Second, this template was used to correct the rising edge of PPG at all wavelengths, and the difference of absorbance was calculate, and then a single-trial DS was obtained; finally, the single-trial DS which contained the gross error under the 3sigma criterion was removed, and then the remaining superimposed single-trial DS was averaged as the final output of the DS. Data measured from 10 volunteers were compared with the results of the extraction in frequency domain: the correlation coefficient distribution of the DS from the same finger of the same individual was improved from 0.

[Noninvasive prediction of red blood cell counts by normalized reflection spectroscopy for tongue inspection].

The technology of visible-infrared (Vis-NIR) spectroscopy for tongue inspection was used for the noninvasive prediction of red blood cell counts (RBC). Reflectance spectra on the tongue tips of 240 volunteers were collected, and the tongue picture was recorded at the same time. Samples were separated into two parts: calibration sample and prediction sample.

[Rapid diagnosis of TCM syndrome based on spectrometry].

Tongue color provides important information in traditional Chinese medicine (TCM) diagnosis, but in the process of TCM inspection, the various surrounding environment and subjective effect of doctors will influence the correctness of diagnosis. The present article put forward a brand new thought to study TCM objectivity, that is to research the essence message of tongue from perspective of spectrum, study the continuous spectrum to replace the observation of tongue color. The experiment used near infrared spectrum to collect reflection spectrum data of tongue among 53 exterior cold and interior heat patients, 37 healthy people and 21 wind chill suffers.

[Application of wavelet transform on improving detecting precision of the non-invasive blood components measurement based on dynamic spectrum method].

Time-varying noises in spectra collection process have influence on the prediction accuracy of quantitative calibration in the non-invasive blood components measurement which is based on dynamic spectrum (DS) method. By wavelet transform, we focused on the absorbance wave of fingertip transmission spectrum in pulse frequency band. Then we increased the signal to noise ratio of DS data, and improved the detecting precision of quantitative calibration.