Monday, May 14, 2012

Hematocrit Centrifuge


I am sure many of you guys have heard of D-Lab... but just in case I'll explain: D-Lab is a group at MIT that designs solutions to problems in the third world, they try to alleviate poverty and improve people's quality of life thought Design, Dialogue and Dissemination (thus the D in D-Lab).

I took D-Lab Design this semester and out team designed a Hematocrit Centrifuge! A H. Centrifuge is a key tool in diagnosing anemia, you basically spin blood for 5 min and then look at the proportion of red to clear solution (red blood cells to plasma) and from this you can diagnose anemia (a normal human has 40-45% red stuff). Given that most people with anemia live in the developing world, they need rapid ways to diagnose it however industry grade centrifuges cost more than a $1000 and require electricity which is a no-no for a lot of rural clinics out there.

Thus our team designed a centrifuge that could be built for around $40-100 using a power drill transmission. We took apart a drill and used the gear box to provide a good gear reduction for the spinning of blood. Here is a picture of the final design:

Our design has a footprint of about 1' by 1' by < 2', which is a big reduction from our Nigerian Community partner's bike centrifuge. My favorite feature of the centrifuge is that we put in a loose nut in the handle that rattles around when it goes too slow but when the speed is fast enough the centrifugal acceleration overcomes gravity and the nut sticks to the outside. This is how we make sure we are spinning the blood fast enough. Here is some of the math:

wooo! 2.003 in action!

I had my blood drawn at a clinic and then we spun the blood and got pretty good results! We even spun some diluted blood (to simulate anemic conditions):

woooo! I am not anemic!

My group is continuing our communications with Dr. Awojobi (an awesome doctor/designer in Nigeria) to flesh out details on a new design of a centrifuge based on a hand drill. So far he has sent us this picture of his progress so far:

exciting prototype!

Hopefully he can implement this new design successfully in Nigeria and disseminate it around the world! Meanwhile I will try and see if people back home in El Salvador have an interest in the hand crank centrifuge we built! I'll keep you guys posted! Here is a video of us testing out the centrifuge (a big shout out to my awesome teammates (Melvin Salinas, Kwami "The King" Williams, Daisy Chang and Kevin Kung)

(a shout out for my other roomie and lil bro David who I just learned also has a blog!)

UPDATE: 16 May 2012

Dr Awojobi (our partner from Nigeria) just emailed us saying that he has successfully implemented hand drills into his prototype and came up with a model that is about a third of the size of the prototype he has been using for 11 years and costs half as much! Here is a pic:

It is really exciting to see that what we worked on during the semester has had real impact on a someones life!

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