Purpose: The purpose of this study was to evaluate the change in corneal wavefront aberrations in young adults who have been fit with multifocal soft contact lenses for myopia progression control. Findings have been a...Purpose: The purpose of this study was to evaluate the change in corneal wavefront aberrations in young adults who have been fit with multifocal soft contact lenses for myopia progression control. Findings have been analyzed for statistical significance and clinical relevance and compared to reportedly successful Orthokeratology outcomes. Methods: The dominant eye of 40 participants (27 women, 13 men;mean age 27.3 ± 3.2 years;range 23 to 39 years) was fit with Proclear Multifocal center distance lenses (Coopervision, Pleasanton, USA) having a variety of distance powers and reading additions. Refractive errors were limited to a range of –6.00 D up to +1.00 D of sphere, and no greater than –1.00 D of cylinder. Corneal wavefront measurements were performed over 6 mm diameters with a Zeiss Atlas 9000 corneal topographer (Zeiss Meditec, Dublin, USA) prior to, and following lens fitting. Data were converted into rectangular Fourier optics terms M, J0, J45 and RMS values for each reading addition were statistically analyzed. Following evaluation of statistical significance and clinical relevance, results were compared to published data from successful Orthokeratology treatments. Results: Statistically significant changes in higher order aberrations were detected for lenses of all reading additions. Lens groups with higher Add-powers demonstrated stronger changes with increased significance. Final RMS values relating to 2nd, 3rd and 4th Zernike Orders reached clinical significance with a wavefront error of 0.10 μm, the equivalent of 0.25D. Moreover, as Add-powers increased, 3rd and 4th order aberrations likewise showed an increase. Pre-fitting astigmatism values accounted for the highest recorded aberrations and remained predominantly unchanged. Conclusion: Proclear Multifocal center-distance contact lenses were found to increase higher order wavefront aberrations in a manner dependent on their Add-power. In comparison to successful Orthokeratology outcomes, the amounts of resulting aberrations are notably different.展开更多
柔性多状态开关(soft open point, SOP)与传统联络开关相比功能更多,响应速度更快,是实现电力网络柔性互联的重要装置之一。SOP中开关器件的存在使系统运行状态在连续系统和离散系统间来回切换,提出对SOP采用更为合适的混杂系统模型进...柔性多状态开关(soft open point, SOP)与传统联络开关相比功能更多,响应速度更快,是实现电力网络柔性互联的重要装置之一。SOP中开关器件的存在使系统运行状态在连续系统和离散系统间来回切换,提出对SOP采用更为合适的混杂系统模型进行建模控制。首先对各端口的8种开关模态进行分析,然后将1个工频周期分为12个子区间,通过系统连续状态量和各开关模态的关系推导出各子区间内开关模态的切换规则,依据切换规则设计了离散控制器,根据连续状态量相互之间的转换关系设计了连续控制器,综合得到了各端口在不同运行模式下的混杂控制器,最后在MATLAB/Simulink中搭建仿真模型,通过与传统建模控制方法的仿真对比,验证了所提方案的有效性。展开更多
文摘Purpose: The purpose of this study was to evaluate the change in corneal wavefront aberrations in young adults who have been fit with multifocal soft contact lenses for myopia progression control. Findings have been analyzed for statistical significance and clinical relevance and compared to reportedly successful Orthokeratology outcomes. Methods: The dominant eye of 40 participants (27 women, 13 men;mean age 27.3 ± 3.2 years;range 23 to 39 years) was fit with Proclear Multifocal center distance lenses (Coopervision, Pleasanton, USA) having a variety of distance powers and reading additions. Refractive errors were limited to a range of –6.00 D up to +1.00 D of sphere, and no greater than –1.00 D of cylinder. Corneal wavefront measurements were performed over 6 mm diameters with a Zeiss Atlas 9000 corneal topographer (Zeiss Meditec, Dublin, USA) prior to, and following lens fitting. Data were converted into rectangular Fourier optics terms M, J0, J45 and RMS values for each reading addition were statistically analyzed. Following evaluation of statistical significance and clinical relevance, results were compared to published data from successful Orthokeratology treatments. Results: Statistically significant changes in higher order aberrations were detected for lenses of all reading additions. Lens groups with higher Add-powers demonstrated stronger changes with increased significance. Final RMS values relating to 2nd, 3rd and 4th Zernike Orders reached clinical significance with a wavefront error of 0.10 μm, the equivalent of 0.25D. Moreover, as Add-powers increased, 3rd and 4th order aberrations likewise showed an increase. Pre-fitting astigmatism values accounted for the highest recorded aberrations and remained predominantly unchanged. Conclusion: Proclear Multifocal center-distance contact lenses were found to increase higher order wavefront aberrations in a manner dependent on their Add-power. In comparison to successful Orthokeratology outcomes, the amounts of resulting aberrations are notably different.
文摘柔性多状态开关(soft open point, SOP)与传统联络开关相比功能更多,响应速度更快,是实现电力网络柔性互联的重要装置之一。SOP中开关器件的存在使系统运行状态在连续系统和离散系统间来回切换,提出对SOP采用更为合适的混杂系统模型进行建模控制。首先对各端口的8种开关模态进行分析,然后将1个工频周期分为12个子区间,通过系统连续状态量和各开关模态的关系推导出各子区间内开关模态的切换规则,依据切换规则设计了离散控制器,根据连续状态量相互之间的转换关系设计了连续控制器,综合得到了各端口在不同运行模式下的混杂控制器,最后在MATLAB/Simulink中搭建仿真模型,通过与传统建模控制方法的仿真对比,验证了所提方案的有效性。
