QuickDx is a low-cost, AI-powered computational microscope designed to perform stain-free microscopic image analysis for rapid diagnostics in rural and resource-limited settings. It combines custom optics, programmable multi-angle illumination, and machine learning to make microscopy more accessible where traditional laboratory infrastructure is unavailable.
Production of the microscope
Due to the usage of PETG HF to print our microscope, the tolerances were messed up for the lens tube, in which the small threads shrank making the lens fit very loosely. Additionally, PETG HF was too flexible causing the lens’ threads to slip. The calculation to get the perfect diameter for the timing pulley to create a sustainable pulley and belt system failed, causing to print it multiple times to get it perfectly.
After making the gear translation system in order to simultaneously spin the screws to raise the stage, me and my partners decide it is best to use a custom made timing pulley and timing belt instead to translate the rotations. We designed the timing pulley translation system around a 200 mm diameter belt found in amazon. Each of the timing pulley is 30 mm in diameter. After acquiring the correct dimensions for the translation system, we integrated the system into the lens case which is the greyish part in the picture below. The lens case is design to hold the lens and the raspberry pi camera to successfully analyze the blood sample. Furthermore, we extended the screw to span the entire lens case so when accessing the low cost microscope it will be easier to lower and raise the stage. In order to provide structural stability for the extended screws we integrated 8 mm ID ball bearings within the lens case itself.
Lastly, we made lens spacer to accurately space the distance between the raspberry pi camera and the 40x lens
Gear Transition system
In the previous design, I CADed 2 leaded screws in order to raise the stage with blood sample in very precise increments in order to get raspberry pi camera into focus, so that it can detect the disease as accurately as possible.
In order to raise the stage accurately without having any tilt, which can be caused by different spins of the leaded screw.
To solve this issue, I integrated a gear translation system with a torque gear ratio in order to make the leaded screws spin at the same time and in the same direction. Additionally, the torque gear ratio lets the stage raise slowly.
Updated the Stage Design
The stage holds the blood sample to be analyzed and detected by the QuickDX AI. And generally microscopes have a stage that can be lowered and raised up to the lens for clarity and easy inserting of the sample. So I added the translational capabilities by using a leaded screw system widely seen in 3D printers. And I made the pitch about 2 mm in order to have slow and precise positioning. Additionally, in order to smooth down the motion I used ball bearings.
I am currently printing this structure using Black PETG HF for faster prototyping. I hope the tolerances turn out well because of the shrinkage problem with PETG HF.
I got to this design after many initial iterations, but still i am not done because I need to add a gear train system so that by rotating one knob in the microscope. I will be able to spin both of the leaded screws in the current direction
