3D Printing Brains

Pictured: Members of the CSL at the summer partyPhoto via CSL website

Center for the Study of Learning and 3D Printing Brains

Spring and Summer 2018

As part of my Cognitive Neuroscience course during the Fall of 2017 I decided to write my term paper on dyslexia in the brain. In preparation for this paper I sent an email to Dr. Guinevere Eden, a researcher at Georgetown and head of the Center for the Study of Learning (CSL). The CSL conducts research investigating the neural basis of learning and its disorders, including dyslexia and dyscalculia. Dr. Eden was a great resource and helped a lot with the theoretical aspects of my paper. After I completed my paper–entitled "Dyslexia and Reading Comprehension: Discovering the Effects of Focused Remediation on Brain Structure and Function"–I was invited to stay at the CSL as an assistant.

During my time as an assistant I was tasked primarily with quality control of the structural MRI data. The data I was looking at had to be manually scrolled through and checked to ensure that the boundaries between white and gray matter were correctly delineated by the program we were using, Freesurfer. Once the semester ended I was once again invited to stay, this time as a research assistant during the summer in order to help with the acquisition of neuroimaging data in their latest study. Naturally, I accepted.

I had the chance to get my own MRI as a part of the study, which was very cool. I had never been in an MRI before, and doing tasks while inside was an interesting challenge. As a part of that I was allowed to have the file that contained the image of my brain, represented as three separate planes through the brain: coronal, sagittal, axial. With the help of some of CSL's graduate students (Cameron McKay, Gabrielle-Ann Torre, and Sikoya Ashburn) I turned my neuroimaging file into a 3D model.

Coronal Slice

Includes my parietal and temporal lobes

Sagittal Slice

Includes corpus callosum and my tongue!

Axial Slice

Includes eyeballs and optic nerve

3D image created from the three slices

3D model of my brain created with Freesurfer

Thanks to Cameron for generating this file!

The next step was to actually 3D print my brain. I used 3mm PLA filament on an Ultimaker 2, and the print time was roughly 6 days. I had a small hiccup when the raft was printing, but after I fixed that jam it was off an running without any issues. Since this was my first print I did not mess around with any support angle or infill settings, which likely could have saved me a lot of filament and cleanup time. Oh well, live and learn.

I was not the only one in the CSL to print my brain: Cameron and Sikoya had done so already. Eventually Dr. Eden and some others in the lab thought it would be a good idea to print the brains of the participants in our study as a thank you for their time and effort. In order to take a bit of a break from the monotony of white matter segmentation in Freesurfer I took an active roll in making sure the project got done in time to deliver the brains to each participant on their last day in the scanner. During that period I printed the brains of each of our 26 participants at roughly a 30% scale. The filament I used for these prints were heat-sensitive color changing (blue → white) and UV-sensitive color changing (white → pink).

5 scaled brains

I organized the brains like this on the build plate to increase efficiency

White to pink color change filament

I printed all of these brains on Makerbot Replicator machines with 1.75mm PLA filament. The blue brains in the image above had stringing between them along with a few other issues that made cleanup more difficult. I spent a few weeks adjusting the print settings in order to have minimal cleanup, since the sulci and gyri of the 30% scale brains make it a hassle. After adjusting the extruder temperature, infill density, and support angle and density I had prints coming out that were much easier to clean up before giving to the participants.

My rough estimate of total print time amounts to 155 hours, as each brain took 5-6 hours to print. I spent about 20 minutes on each brain cleaning up strings of filament from the cortex surface or getting rid of support material from underneath. I practically lived in the MakerHub, Georgetown's on-campus maker space and home to the wonderful 3D printers.

Overall I have a few takeaways from the entire experience. The first is that 3D printing is awesome: having the ability to take a 3D object represented on my screen and hold it in my hand within 5-6 hours is an incredible thing. Its applications are far-reaching, and I can't wait to explore it more. Second, I think that getting the participants involved in the study by giving them a physical reminder of their time with us was hugely beneficial. Previously the participants only received the 2D images of their brain like mine above; seeing their faces light up when I showed them their own brain in a way that they could interact with made my day every time. Finally, this experience taught me how to be creative in a new way, how to problem solve, and how to manage my time in a larger project with important deadlines.

Im grateful for my entire time in the CSL, and I could not have accomplished this task without the help of those in my lab and the entire MakerHub staff, especially Don Undeen. Thank you to all of you, and thanks for reading!