Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It i...Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It is observed that a properly designed multi belt complex phase filter can generate subwavelength novel focal patterns including splitting of focal spots and generation of multiple focal spot segments such as eight, six and four focal spots along the optical axis are obtained. We expect that such an investigation is useful for optical manipulation and material processing, multiple high refractive index particle trapping technologies.展开更多
Nonlinear analysis of heart rate variability （HRV） has become important as heart behaves as a complex system. In this work, the approximate entropy （ApEn） has been used as a nonlinear measure. A new concept of est...Nonlinear analysis of heart rate variability （HRV） has become important as heart behaves as a complex system. In this work, the approximate entropy （ApEn） has been used as a nonlinear measure. A new concept of estimating the ApEn in different segments of long length of the recorded data called modified multiple scale （segment） entropy （MMPE） is introduced. The idea of estimating the approximate entropy in different segments is useful to detect the nonlinear dynamics of the heart present in the entire length of data. The present work has been carried out for three cases namely the normal healthy heart （NHH） data, congestive heart failure （CHF） data and Atrial fibrillation （AF） data and the data are analyzed using MMPE techniques. It is observed that the mean value of ApEn for NHH data is much higher than the mean values for CHF data and AF data. The ApEn profiles of CHF, AF and NHH data for different segments obtained using MPE profiles measures the heart dynamism for the three different cases. Also the power spectral density is obtained using fast fourier transform （FFT） analysis and the ratio of LF/HF （low frequency/high frequency） power are computed on multiple scales/segments namely MPLH （multiple scale low frequency to high frequency） for the NHH data, CHF data and AF data and analyzed using MPLH techniques. The results are presented and discussed in the paper.展开更多
AIM:To compare the effect of orthokeratology(OK)and defocus incorporated multiple segment(DIMS)lenses on axial length(AL)elongation in bilateral myopic anisometropic children.METHODS:This retrospective study enrolled ...AIM:To compare the effect of orthokeratology(OK)and defocus incorporated multiple segment(DIMS)lenses on axial length(AL)elongation in bilateral myopic anisometropic children.METHODS:This retrospective study enrolled bilateral myopic anisometropic children categorized into two groups:OK lenses and DIMS lenses.The eyes with more myopia(MM)were divided into MM eyes and the fellow eyes with less myopia(LM)into LM eyes.According to the myopia degree in MM eyes,the subjects were further assigned to-0.50 to-3.00 D subgroup and-3.25 to-6.00 D subgroup.The t-test was used to analyze the changes in AL elongation between groups and AL differences in both eyes,and the relationship between AL changes and baseline data was evaluated by Pearson linear correlation analysis.RESULTS:Totally 202 children(8-14y)were divided into OK group with mean age 10.97±1.91y(46 males and 50 females)and DIMS group with mean age 11.05±2.06y(58 males and 48 females).After 1y,the changes of AL in OK-MM eyes(0.14±0.18 mm)were significantly slower than that in OK-LM eyes(0.20±0.19 mm)and DIMS-MM eyes(0.19±0.18;P<0.001,P=0.037).The OK-LM eyes and DIMS-LM eyes,DIMS-MM eyes and DIMS-LM eyes showed no statistically significant difference in AL changes(P=0.337,0.381).In the-0.50 to-3.00 D subgroups,DIMSLM eyes had better effect of AL control than OK-LM eyes,the changes of AL in OK-MM eyes and DIMS-MM eyes were no statistically significant.In the-3.25 to-6.00 D subgroups,the results were similar in total group.The change of AL in four subgroups was negatively correlated with age(P<0.05).CONCLUSION:OK lens can reduce binocular anisometropia;DIMS lens has similar effect on the control of binocular myopia in children with myopic anisometropia.The OK lenses are more effective than DIMS lenses with higher degrees of myopia,while DIMS lens retard AL elongation more effectively than OK lens when the spherical equivalent refraction of MM eyes is lower than-3.00 D.展开更多
A fast interactive segmentation algorithm of image-sequences based on relative fuzzy connectedness is presented. In comparison with the original algorithm, the proposed one, with the same accuracy, accelerates the seg...A fast interactive segmentation algorithm of image-sequences based on relative fuzzy connectedness is presented. In comparison with the original algorithm, the proposed one, with the same accuracy, accelerates the segmentation speed by three times for single image. Meanwhile, this fast segmentation algorithm is extended from single object to multiple objects and from single-image to image-sequences. Thus the segmentation of multiple objects from complex hackground and batch segmentation of image-sequences can be achieved. In addition, a post-processing scheme is incorporated in this algorithm, which extracts smooth edge with one-pixel-width for each segmented object. The experimental results illustrate that the proposed algorithm can obtain the object regions of interest from medical image or image-sequences as well as man-made images quickly and reliably with only a little interaction.展开更多
文摘Based on the vector diffraction theory, the effect of complex phase filters on intensity distribution of a radially polarized multi Gaussian beam in the focal region of high NA lens is theoretically investigated. It is observed that a properly designed multi belt complex phase filter can generate subwavelength novel focal patterns including splitting of focal spots and generation of multiple focal spot segments such as eight, six and four focal spots along the optical axis are obtained. We expect that such an investigation is useful for optical manipulation and material processing, multiple high refractive index particle trapping technologies.
文摘Nonlinear analysis of heart rate variability （HRV） has become important as heart behaves as a complex system. In this work, the approximate entropy （ApEn） has been used as a nonlinear measure. A new concept of estimating the ApEn in different segments of long length of the recorded data called modified multiple scale （segment） entropy （MMPE） is introduced. The idea of estimating the approximate entropy in different segments is useful to detect the nonlinear dynamics of the heart present in the entire length of data. The present work has been carried out for three cases namely the normal healthy heart （NHH） data, congestive heart failure （CHF） data and Atrial fibrillation （AF） data and the data are analyzed using MMPE techniques. It is observed that the mean value of ApEn for NHH data is much higher than the mean values for CHF data and AF data. The ApEn profiles of CHF, AF and NHH data for different segments obtained using MPE profiles measures the heart dynamism for the three different cases. Also the power spectral density is obtained using fast fourier transform （FFT） analysis and the ratio of LF/HF （low frequency/high frequency） power are computed on multiple scales/segments namely MPLH （multiple scale low frequency to high frequency） for the NHH data, CHF data and AF data and analyzed using MPLH techniques. The results are presented and discussed in the paper.
基金Supported by the Aier Eye Hospital Fund Project(No.AGF2503D08).
文摘AIM:To compare the effect of orthokeratology(OK)and defocus incorporated multiple segment(DIMS)lenses on axial length(AL)elongation in bilateral myopic anisometropic children.METHODS:This retrospective study enrolled bilateral myopic anisometropic children categorized into two groups:OK lenses and DIMS lenses.The eyes with more myopia(MM)were divided into MM eyes and the fellow eyes with less myopia(LM)into LM eyes.According to the myopia degree in MM eyes,the subjects were further assigned to-0.50 to-3.00 D subgroup and-3.25 to-6.00 D subgroup.The t-test was used to analyze the changes in AL elongation between groups and AL differences in both eyes,and the relationship between AL changes and baseline data was evaluated by Pearson linear correlation analysis.RESULTS:Totally 202 children(8-14y)were divided into OK group with mean age 10.97±1.91y(46 males and 50 females)and DIMS group with mean age 11.05±2.06y(58 males and 48 females).After 1y,the changes of AL in OK-MM eyes(0.14±0.18 mm)were significantly slower than that in OK-LM eyes(0.20±0.19 mm)and DIMS-MM eyes(0.19±0.18;P<0.001,P=0.037).The OK-LM eyes and DIMS-LM eyes,DIMS-MM eyes and DIMS-LM eyes showed no statistically significant difference in AL changes(P=0.337,0.381).In the-0.50 to-3.00 D subgroups,DIMSLM eyes had better effect of AL control than OK-LM eyes,the changes of AL in OK-MM eyes and DIMS-MM eyes were no statistically significant.In the-3.25 to-6.00 D subgroups,the results were similar in total group.The change of AL in four subgroups was negatively correlated with age(P<0.05).CONCLUSION:OK lens can reduce binocular anisometropia;DIMS lens has similar effect on the control of binocular myopia in children with myopic anisometropia.The OK lenses are more effective than DIMS lenses with higher degrees of myopia,while DIMS lens retard AL elongation more effectively than OK lens when the spherical equivalent refraction of MM eyes is lower than-3.00 D.
文摘A fast interactive segmentation algorithm of image-sequences based on relative fuzzy connectedness is presented. In comparison with the original algorithm, the proposed one, with the same accuracy, accelerates the segmentation speed by three times for single image. Meanwhile, this fast segmentation algorithm is extended from single object to multiple objects and from single-image to image-sequences. Thus the segmentation of multiple objects from complex hackground and batch segmentation of image-sequences can be achieved. In addition, a post-processing scheme is incorporated in this algorithm, which extracts smooth edge with one-pixel-width for each segmented object. The experimental results illustrate that the proposed algorithm can obtain the object regions of interest from medical image or image-sequences as well as man-made images quickly and reliably with only a little interaction.
