In today's medical field, endoscopy is widely used, in addition to image transmission, therapeutic functionality is also required. Our customer, a medical endoscopy equipment manufacturer, ran into the problem that saline flushing was used through the empty tube that caused the backflow of saline and foreign objects from the optical channel to the handle, blockage at the tip, resulting in the loss of image and an increased risk of infection for patients. Therefore, the customer contacted SC to assist re-design the particular case.