Development of Photodensitometry System Using Laser Light Source

在过去的一年中，为了将我们的激光光密度测量系统投入实际应用，我们进行了一些实验，对设备的基本设计作了部分修改：用市售的PIN光电二极管和放大器代替了国产的放大器。由于Visual Basic在用户界面方面具有上级，并且发现它可以在MS-DOS上使用，因此Quick Basic编程更改为Visual Basic编程。关于胶片扫描的条件，接收光的设备中的狭缝的直径暂时设置为300 μ m，并且胶片的最小移动距离固定为100 μ m。还证实，其他参数可以以恒定关系确定。利用该系统，可以测量膜中任意点、两点之间的直线上以及矩形区域内的浓度。由于个人计算机的主存储器容量（640 KB）和小于64 KB的程序安排的限制，一维或二维FFT和各种数据的处理与其他软件如PC-98专用的图形软件（N graph）和图像处理软件（NIH Image）结合使用。预计将进一步积累临床数据，包括应用于显微密度测定。

During the past year, to put our photodensitometry system using a laser light source into practice, some experiments have been performed.The fundamental design of the equipment was partially changed : PIN photodiode and a homemade amplifier were replaced with commecially available ones. As Visual Basic, which is superior in its user interface, was found to be available on MS-DOS, programming by Quick Basic was changed to programming by Visual Basic. With regard to the conditions of the film scan, the diameter of the slit in the apparatus reciving light was temporarily set at 300mum, and the minimum moving distance of film was fixed at 100mum. It was also confirmed that other parameters could be determined in constant relation. With this system, the concentrations at an arbitrary point in the film, on a line between two pionts, and in a rectangular area could be measured. The results of the measurements obtained were saved as text-data.Because of limitations in the main memory volume (640KB) of the personal computer and in programming in arrangements of less than 64KB, FFT of one or two dimensions and processing of various data were used in combination with other software such as graph-softwafe (N graph) specified for the PC-98 and image processing software (NIH Image). Further accumulation of clinical data including application to microdensitometry is expected.