Teaching College Students Principle of Endoscopes Through an Educational Method of Image Processing

We gave a lecture regarding the principles of endoscopes to students studying medical engineering. The following was the lecture. The light from the light source passed through the rotating RGB filter, and changed to a red, a green, and a blue light, respectively, and these three colored lights illuminated an object. Each light reflected from the object passed through a lens and was received by the CCD. The light signals were changed into electric signals by the CCD, and the memory recorded the red, green, and blue electric signals. The video processor processed these color signals. And, the image of the object was displayed on the monitor. Next, we gave a lecture about RGB colors to the students. The RGB color model was an additive color model of red, green, and blue light. The model could reproduce a broad array of colors using various ways. To allow the students to experience these principles, we gave the students an experimental subject. We prepared a CCD camera, RGB filters, a power supply code, and a video cable. The CCD camera was a Super Color Camera NA-C2660. The RGB filters were the additive types of Dichroic Color Filters that were manufactured by Edmund Optics, Co. These filters were three of colors: red, green, and blue. The video capture board was an Analog Video Capture Board GV-VCP3R/PCI that was manufactured by I-O DATA Device, Inc. Students were divided into 36 groups with 5-6 students in each group. The students combined the three images photographed with the RGB filters, and performed the image processing. The students compared the RGB values of the combined images with the RGB values of the normal image. They brought the RGB value of the combined image as close as possible to the RGB value of the normal image using the Paint Shop Pro 8 software. Next, the differences in the RGB values between the normal image and the modified image were calculated; the maximum of those values was extracted. According to the results, the number of the groups whose difference of the RGB value were greater than 5 and less than or equal to 10 showed the maximum. Moreover, the group which showed the 2nd value was the group whose difference of the RGB value were less than or equal to 5. In the end, the students could experience the principles of endoscopes and image processing.