十字线目标作为调焦系统中的常见目标,其调焦精度是影响调焦系统测量结果的关键因素。传统的调焦函数在灵敏度和实时性方面不能完全满足自动调焦要求。基于调制传递函数(modulation transfer function,MTF)的自动调焦算法通过连续测量...十字线目标作为调焦系统中的常见目标,其调焦精度是影响调焦系统测量结果的关键因素。传统的调焦函数在灵敏度和实时性方面不能完全满足自动调焦要求。基于调制传递函数(modulation transfer function,MTF)的自动调焦算法通过连续测量多幅图像在固定频率下的MTF值绘制调焦曲线,得到调焦曲线的唯一极值点即正焦位置;在Matlab运行环境下,与现有算法进行比较,结果表明,基于数字图像MTF的调焦函数可实现单张图片的清晰度值计算仅用0.01 s,该算法实时性更好、灵敏度更高,具有应用价值。展开更多
Saturation of peripheral oxygen （SpO2） is one of the most important parameters of vital signs. Pulse oximeter based on near-infrared spectroscopy is commonly used as a non-invasive method to measure SpO2 yl. Current...Saturation of peripheral oxygen （SpO2） is one of the most important parameters of vital signs. Pulse oximeter based on near-infrared spectroscopy is commonly used as a non-invasive method to measure SpO2 yl. Currently, medical device manufacturers as well as metrology measurement agencies in China usually use pulse oximeter simulator as the commonly accepted functional calibration equipment for pulse oximeters. So far, no experimental protocol or devices can be used to test the accuracy and reliability of a pulse oximeter simulator. Therefore, a set of new metrology apparatus with the name of calibration device for pulse oximeter simulator have been designed in order to make a traceable system for the calibration or verification of pulse oximeter simulators. The principles and some research methods of this calibration device for pulse oximeter simulator will be discussed in this paper. Besides that, many experiments have been applied in order to guarantee the accuracy as well as traceability of this set of device.展开更多
文摘十字线目标作为调焦系统中的常见目标,其调焦精度是影响调焦系统测量结果的关键因素。传统的调焦函数在灵敏度和实时性方面不能完全满足自动调焦要求。基于调制传递函数(modulation transfer function,MTF)的自动调焦算法通过连续测量多幅图像在固定频率下的MTF值绘制调焦曲线,得到调焦曲线的唯一极值点即正焦位置;在Matlab运行环境下,与现有算法进行比较,结果表明,基于数字图像MTF的调焦函数可实现单张图片的清晰度值计算仅用0.01 s,该算法实时性更好、灵敏度更高,具有应用价值。
文摘Saturation of peripheral oxygen （SpO2） is one of the most important parameters of vital signs. Pulse oximeter based on near-infrared spectroscopy is commonly used as a non-invasive method to measure SpO2 yl. Currently, medical device manufacturers as well as metrology measurement agencies in China usually use pulse oximeter simulator as the commonly accepted functional calibration equipment for pulse oximeters. So far, no experimental protocol or devices can be used to test the accuracy and reliability of a pulse oximeter simulator. Therefore, a set of new metrology apparatus with the name of calibration device for pulse oximeter simulator have been designed in order to make a traceable system for the calibration or verification of pulse oximeter simulators. The principles and some research methods of this calibration device for pulse oximeter simulator will be discussed in this paper. Besides that, many experiments have been applied in order to guarantee the accuracy as well as traceability of this set of device.
