Irradiance uniformity is an important parameter for a Photodynamic Therapy(PDT)device.The calibration and verification of a LED array light source based on computer vision technology were implemented and carried out.F...Irradiance uniformity is an important parameter for a Photodynamic Therapy(PDT)device.The calibration and verification of a LED array light source based on computer vision technology were implemented and carried out.First,the correlation coe±cients between the pulse width modulate value and the irradiance were calibrated.Then,the correction of the actual light center and divergence angle were solved by image processing to reduce errors from each LED lens.Finally,uniformity was optimized according to the irradiance formula of the Lambertian source.The lowest coe±cients of variation of irradiance were 4.87%in a 5 cm×12 cm area and 3.55%in a 3 cm×10 cm area within the depth range of 8–12 cm when the expected irradiance was 100 mW/cm^(2).This finding indicated that the light source can achieve a more uniform illumination and provide a better therapeutic effect for the PDT of port-wine stains.展开更多
A method has been proposed to model the illumination characteristics of a typical wire bonder vision system. The proposed model can be used to calibrate the illumination of the vision system to ensure the same level o...A method has been proposed to model the illumination characteristics of a typical wire bonder vision system. The proposed model can be used to calibrate the illumination of the vision system to ensure the same level of illumination brightness across different machines, given the same lighting level setting. The approach to extract the machine illumination model is semi-empirical and the model provides a closed-form solution.展开更多
基金This research was supported by the National Natural Science Foundation of China(Grant No.81773349).
文摘Irradiance uniformity is an important parameter for a Photodynamic Therapy(PDT)device.The calibration and verification of a LED array light source based on computer vision technology were implemented and carried out.First,the correlation coe±cients between the pulse width modulate value and the irradiance were calibrated.Then,the correction of the actual light center and divergence angle were solved by image processing to reduce errors from each LED lens.Finally,uniformity was optimized according to the irradiance formula of the Lambertian source.The lowest coe±cients of variation of irradiance were 4.87%in a 5 cm×12 cm area and 3.55%in a 3 cm×10 cm area within the depth range of 8–12 cm when the expected irradiance was 100 mW/cm^(2).This finding indicated that the light source can achieve a more uniform illumination and provide a better therapeutic effect for the PDT of port-wine stains.
文摘A method has been proposed to model the illumination characteristics of a typical wire bonder vision system. The proposed model can be used to calibrate the illumination of the vision system to ensure the same level of illumination brightness across different machines, given the same lighting level setting. The approach to extract the machine illumination model is semi-empirical and the model provides a closed-form solution.
