[Spectral measurement system and laser therapy experiments for port wine stains].

To measure and analyze the spectrum of a small skin region for laser therapy of port wine stain is very useful for clinical doctor to understand the optical characters of patient's pigmented skin, to adjust the output parameters of lasers and then to improve the therapy effects. Based on the analysis of the forming mechanism of port wine stains and clinical operation of the disease, the present paper presents an automatic spectral measurement and analysis system for port wine stain therapy. It can accomplish the spectral detection in the range from 380 to 780 nm, with a spectral resolution of 1 nm. Experiments were performed for patients with various age and pigment diseases; finally, some influencing factors and relevant solutions are enumerated and discussed.

[Design of a portable UV-Vis spectrophotometer].

In the present paper, a method for how to design a portable UV-Vis spectrophotometer is introduced. The Hamamatsu multichannel detector S3904-1024Q and a flat field concave grating are employed to design a miniaturized dispersion system. In order to solve the contradiction between the spectral width and energy-utilizing ratio of the light source, a multi-band optical fiber is employed, one side of which is arranged to be rectangle as the entrance slit. The touch screen is employed as the input and output system of the spectrophotometer, and the miniaturized fiber-optic UV-Vis light source is employed as the light source. The research results and testing results of the prototype show that the new spectrophotometer based on the authors' new method is of miniaturization in volume(190 mm x 170 mm x 100 mm), can realize multi-wavelength-detection on-line, and is easily handled (touch screen control), and its performance accords with the Chinese national standard.

[Preprocessing of near infrared spectroscopic data].

Spectroscopic data of samples recorded by spectroscopic instruments are confused by a series of noises, and interferences, therefore the proper data preprocessing is the basis of the following spectroscopic calibration, model establishment and transference, which is very important for the achievement of accurate analytical results. This paper reports our research work, combined with NIR spectroscopic analyses of the protein contents of wheat, that is the preprocessing of NIR spectral data recorded for 66 different wheat samples by a NIR grating spectrophotometer and a NIR Fourier transform spectrometer, respectively. The preprocessing algorithm is wavelet transform with the Gaussian first and second order derivatives. Compared with the result of preprocessing by normal first order difference algorithm, the wavelet transform algorithm by Gaussian derivatives was proved to be very effective and applicable, the spectra were smoothed perfectly, noises were eliminated obviously, and the spectral sections, which include all useful information for spectral analyses, were displayed clearly. So, it is very beneficial to the following spectral calibration, model establishment and transference.