Eye tracker is a new apparatus of human-computer interaction, which has caught much attention in recent years. Eye tracking technology is to obtain the current subject’s "visual attention (gaze)” direction by using mechanical, electronic, optical, image processing and other means of detection. While the mapping function is one of the key technology of the image processing, and is also the determination of the accuracy of the whole eye tracker system. In this paper, we present a new mapping model based on the relationship among the eyes, the camera and the screen that the eye gazed. Firstly, according to the geometrical relationship among the eyes, the camera and the screen, the framework of mapping function between the pupil center and the screen coordinate is constructed. Secondly, in order to simplify the vectors inversion of the mapping function, the coordinate of the eyes, the camera and screen was modeled by the coaxial model systems. In order to verify the mapping function, corresponding experiment was implemented. It is also compared with the traditional quadratic polynomial function. And the results show that our approach can improve the accuracy of the determination of the gazing point. Comparing with other methods, this mapping function is simple and valid.
A LED array is used as PDT light source in a photo-reaction chamber. The LED array is alterable in wavelength by
replacing different LEDs, stable in output power, adjustable in power value and spot size; the geometry of the LED array
is flat shape. Based on the experiment of ALA-PDT, we measured and analyzed the spectrum characteristics and output
power of some different purple LEDs, selected one as PDT light source whose emission peak is near the absorption peak
of the ALA. The experiment on HL60 tumor cells in vitro demonstrates our photo-reaction chamber has visible
photodynamic effect on ALA-PDT.
Based on the morphological differences between normal, apoptosis and necrosis cell, a new method for detection cell viability is presented in the paper. The Jurkat cells samples were used for studying the relationship between morphological parameters and cell viability in the paper. According to the scatter charts of Jurkat cell roundness, radius ratio and area, the cell areas were mainly distributed from 40 μm2 to 80 μm2. The percentage of main areas in the two cells samples were analyzed statistically with values of 62.37% and 75.45 % respectively. Due to the mostly normal cell used by the experiment in the exponent growth period, a conclusion that the areas of normal cells were mainly distributed from 40 μm2 to 80 μm2 is presented. And the areas of apoptosis and necrosis cells are distributed in other range, i.e. less than 40 μm2 or more than 80 μm2. There are not any chemical medicaments needed to add in the samples by the method based on the videopicture in order to detect the states of cell samples. What it reflected by analyzing morphological parameters of cell are the true states of cell.
The characteristics of ALA emission spectrum and excitation spectrum were studied by comparing the difference of ALA emission spectrum and excitation spectrum in different incubation conditions of Jurkat cell in the paper. The results of test show that the wavelength of the strongest emission spectrum of ALA is 375nm. The wavelength of the strongest excitation spectrum of ALA is 255nm and 290nm. The wavelength of 290nm is better to excite the ALA. Those results will be helpful to diagnose and detect the cancer.
This article describes the work of ALA-PDT to the HL60 cells, which includes parameters of ALA density, Culture time, light dose and optimal wavelength of irradiation, and summarizes the optimize project of experiment using ALA-PD to the HL60 leukaemic cells.