Ali lives and studies at the American School in London, and loves creating new things. He has always been surrounded by science and engineering. From an early age his grandfather kindled his interests in science, he isn’t only a surgeon, but also a science enthusiast who has shown Ali how science can be applied to improve the world we live in. Ali’s father’s family is from Pakistan, but his grandparents have lived in Kenya and Tanzania for most of his life. Visiting family in Pakistan and East Africa has made him more aware of how privileged he is and motivated him to apply science to aid humanity.

Here is Ali’s idea for low cost 3D Printed prosthetics which was submitted to the Google Science Fair.


Written by Ali M. Ahmed

At school, I enjoy math and science, and have traveled multiple times to represent the school in international math competitions. As part of robotics teams I have acquired skills such as CAD designing and 3D Printing. My hopes are to attend a US university furthering my passion for math, science and design. Succeeding in the Google Science Fair would help me make my project a reality.

Below is a picture of me after coming 5th in the individual Junior ISMTF math competition in Zoetermeer, Netherlands.

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Have you considered the consequences of losing a limb? My grandparents are from Pakistan, and have lived in East Africa for the past 13 years. Whenever I visit Karachi, Nairobi or Dar es Salaam, I witness the terrible consequence first hand. At the local mosque or on the streets, the one thing that I realise is that a significant percentage of those in need in these developing countries are amputees without prosthetics.

After researching this issue, I have identified the primary challenges in developing cost effective and customized prosthetics on a meaningful scale in these challenging environments:

  1. Labor intensive, time-consuming and wasteful manufacturing process
  2. Current solutions remain expensive for most
  3. Cost for setting up rehabilitation centers is high because of costly equipment
  4. Shortage of trained professionals outside few key rehabilitation centers
  5. Limited awareness of the availability and benefits of prosthetics

I asked myself whether there is a better way to manufacture prosthetics for these communities. I set out to see if it was possible to design a kit that would enable communities to manufacture prosthetics that are customizable, affordable, and require minimal equipment and expertise. I hypothesised that 3D printing would allow for customization and simplify the manufacturing process. By using recycled plastic material primarily from water bottles, the cost of the feedstock would be zero, eliminate the need for importing plastic filament and would be good for the environment.

Research

Background Research:  

First I wanted to evaluate the different types of commercially available prosthetics for upper limb amputees. Prosthetics that allow people to regain their freedom of mobility come at a high cost. One of the leading prosthetic companies, Bebionic, produces myo-prosthetics that cost upwards of $10,000.

Logically, my research next focused on 3D Printed prosthetics. I soon learnt that people have started to design 3D Printed prosthetics. The two entities that stand out for me are Enable Community and Open Hand. The Enable prosthetic is the most similar in concept and design and they are quite advanced. The Open Hand project has worked on 3D Printed myo-prosthetics, but their design still is assembly intensive relying on tendons, and costs upwards of US $1,000. After learning what the commercial market has to offer, I set off on my next step of research: learning about the state of prosthetics in poorer countries.

Field-Based Research:

I managed to get myself an internship with a prosthetic engineer at the Comprehensive Community Based Rehabilitation in Tanzania (CCBRT). During my internship, I learnt the process currently used in places like CCBRT to manufacture prosthetics. CCBRT uses the common International Committee of Red Cross (ICRC) prosthetic manufacturing guidelines. The process which starts with a negative cast of the patient stump filled in with Plaster of Paris. Trained personnel spend days working the positive cast by sanding, cutting and molding it. After the positive cast is complete, a hard virgin plastic called polypropylene is heated till soft in an oven and vacuum sealed around the cast allowing it to take form. The caste is broken leaving the finished plastic prosthetic.This process uses virgin material and requires multiple machines, personnel and hours. making it bad for the environment and expensive for those who need prosthetics.The price of a prosthetic leg with a locking knee costs around US$500, which is expensive for many living in these poorer countries.

I also interviewed CCBRT patients and their feedback has been important in my design considerations. For example, even though they prefer mobility over the aesthetics, aesthetics are still important. The weight of the prosthetic is an important factor. The CCBRT prosthetics are usually made from machined aluminium. 3D Printed prosthetics are half as heavy because of the density of plastic but also because 3D objects are not solid but are supported by internal structures.

Through all of my research, I have been able to compare many of the main prosthetics. Here is a chart comparing a few:

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Method / Testing and Redesign

Key Milestones:

Step 1: Research – Completed

Step 2: Develop and Design Prosthetic – Completed

Step 3: Test Design on a Patient – Summer 2016

Step 4: Develop kit to convert plastic bottles to 3D Printer filament – Winter 2016

Step 2: In Depth – Developing and Designing Prosthetic

I choose to start designing a transradial myo-prosthetic as it is not only one of the harder prosthetics to design, but it is also one of the most expensive now. If I can design a transradial myo-prosthetic, then I should be able to design other prosthetics quite well.

Design process steps:

1. Sketch Designs

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First, I sketched designs, turning my ideas based on my research, into a format ready to be modelled in a 3D CAD software.

2. CAD Design (Computer-Aided-Design)

i). Designing the Parts

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I used Autodesk Inventor Professional, a 3D CAD program, to convert my sketches into digital 3D models. The program allows you to push and pull 2D sketches to create 3D objects which can then be modelled into a final product.

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This is the first extrusion of my sketch.

 

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This is a finger after several modifications of the first extrusion.

ii). Assembly design

After making all the parts of the prosthetic, I then assemble it digitally on the same program. I can then see if any of the parts interfere with each other

 

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iii). CAM – (Computer-Aided-Machining)

After finishing the design, I export the files into an STL (STereoLithography) file. This is probably the most common 3D design file format utilized by 3D Printing CAM softwares. The problem with converting my design into STL files is that they get scaled down generating errors which have a detrimental effect when it comes to printing them. Here is a picture showing how I repair the STL files in a program called Netfabb.

 

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After repairing the STL file, I use Cura, a 3D Printing CAM software. The program allows me to control the print settings and preview each layer of the 3D object.

 

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iv). Print

After this I print my design

 

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After printing, I test my design and understand how it may need to improve, in order to incorporate those changes in the next design.

 

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Conclusion / Report

After extensive testing and redesign the prosthetic hand I have designed and printed meets the requirements stated by prosthetic engineers and amputees. My latest version is pre-assembled (the only assembly required is adding the motor and electronics into the casing) inexpensive, lightweight with a strong grip. These results support my hypothesis that 3D printing can improve the manufacturing process making it affordable and accessible.

However my work is incomplete. I still need to test my prosthetic on an amputee, and complete the kit to allow communities to print prosthetics from reused plastics at a low cost (please refer to powerpoint in Research section with regards recycling plastics).  My goal is to deliver the kit which includes a 3D Printer, a plastic extruder and plastic grinder, and a library of easy to manipulate prosthetic designs for under US $2,000. Once the kit is in place, the cost of each prosthetic should be less than US $100 because the feedstock for the 3D printer comes from discarded plastic bottles. Delivering the kits broadly in rural communities and less advantaged neighborhoods outside the key population centers will improve access and enhance the quality of life of many people.

3D Printing allows people to print anything. By bringing 3D Printer technology to new communities I hope there is the added benefit of people also applying it to different problems. Hopefully my project will inspire underprivileged communities.

Acknowledgements:

Companies and Groups:

Thank You to Autodesk for providing a free student software enabling me to design my prosthetic in Autodesk Inventor Professional and share them in the A360 viewer.

Thank You to Netfabb for providing a free version of the Netfabb 3D Printer software.

Thank You to Ultimaker and the Ultimaker community for providing a free version of the Cura 3D Printing CAM slicing software.

Thank You once again to Ultimaker for loaning me a printer to help me print my designs

Thank You to CCBRT for Providing me with an internship

People:

Michelle Chatterley from the CREATE Education Project for helping me get connected with other prominent members of the 3D Printing community and for helping loan me the 3D Printer from Ultimaker. My project wouldn’t have gotten this far without her.

Benjamin Mkambati for helping organize my internship at CCBRT

Fortunatus Gitarda for spending so time with me to aid my understand in prosthetics and prosthetic engineering

Chris Goff, for not only being a my robotics mentor ever since I started robotics, but for also giving supportive feedback and advice on my project

Colin McCarty, for not only being my 8th grade science teacher and robotics mentor, but also for providing feedback and support.

Muktar Ali, for not only being my robotics mentor and my 7th grade Design and Health teacher. Without Mr. Ali and his 7th grade Design class, I might have not learnt how to design and use CAD software as well as I do. Also, I and thankful for the feedback and support Mr. Ali provided during this project.

I want to thank all of my family. They have been supportive of my interests in inventing from the start without an exception.

In particular, I want to thank my grandparents. My grandfather motivated me to start this project when I first told him about my ideas, and both my grandfather and grandmother have not only shaped who I am, but also helped me get my internship at CCBRT.

Most importantly of all, I want to thank my parents. They have not only helped me edit this submission, but have also been very supportive of this project. Without them none of this at all would have happened.

Thanks to Ali for sharing this amazing project with us and we wish him the best of luck with it!  

 

 

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