Hand-powered blood sample centrifuge

This centrifuge was designed by Dr Giorgio Romagna, with whom I share my Printables account and my passion for 3D printing. 

The idea for the centrifuge came from a toy I used to play with as a child. It was made from just a thread and a 4-hole button. I am sure many of you have played this simple game.

I designed the centrifuge on Fusion360 and it can spin up to 8 samples at the same time.

The samples are taken from a finger prick using a capillary tube, which is then sealed with wax, placed in one of the slots and balanced on the opposite side by another sample or water filled capillary. Once the cap is in place, the nut is tightened to lock the cap in place during centrifugation.

The Cetrifuge can be spun by one or two people, in the video you can see me spinning it alone after attaching it to my balcony trailing. For best results, spin for 2 to 5 minutes. 

The haematocrit value can be read immediately by placing the capillary tube on a microhaematocrit reader chart. The haematocrit is the percentage of the solid part (mostly red blood cells) in the blood and it is a quick and cheap way to diagnose anaemia. The serum sample obtained can also be collected and used for other tests. 

Print settings:

6 perimeters

6 bottom layers

6 top layers

60% infill gyroid

no support needed

For the string I used approx 6m of paracord 550 

Note: Capillary tube used are standard 200microL cutted in half using a small file to score the glass.