Sometimes a casual conversation can lead you to challenges and, hopefully, solutions that have a major impact on the work you do.
Take the conversation that took place between COMP Professor of Anatomy, Craig Kuehn, PhD, and Gary Wisser, 3D Visualization Specialist that occurred in January 2016. While discussing the general state of 3D scanning and printing at WesternU, Dr. Kuehn approached Gary with a challenge: Could he capture a 3D image of a human heart with an enlarged aorta and turn it into a printed model he could use as a teaching aid in his Gross Anatomy course?
Up to then, 3D modeling almost exclusively involved skeletal structures. Scans of soft tissues were considered infeasible, due mainly to the instability of the tissue during the scanning process. The tabletop scanning process used at that point required that the original object be repeatedly repositioned to capture it from all possible angles. Soft tissues do not generally hold their shape during the process, creating varying deformations that are difficult to resolve in the post-scanning editing process.
Having been preserved in formaldehyde for a number of years, Kuehn’s source model exhibited more rigidity than typical soft tissue specimens, making it potentially scannable. Dr. Kuehn and Gary came up with a simple mount using a wooden base and what amounted to a metal spit, much like an office paper holder. Since the heart already had cuts from previous dissections, the spit could be inserted into the base of the heart without damaging the organ further.
The only problem remaining was how scan the organ from all of the different angles necessary with as little repositioning as possible. The solution presented itself through a fortunate coincidence in timing: ITDL had recently purchased a new portable 3D scanner to enable scanning larger objects than were possible using tabletop techniques. The portability of the new Artec EVA
provided an additional advantage in allowing Gary to perform the scans outside of the office setting and in a laboratory where the fumes from the formaldehyde would not pose a health risk.
The heart securely impaled on the jury-rigged mount, Gary used the Artec EVA to scan all around it and capture the necessary images. With the images now captured, Gary used StudioMax to clean up the images and integrate them into a complete 3D model, which can be seen on our EdMedia website here
A printout was made of the digital model using a Makerbot Replicator Desktop 3D Printer. Since the original colors of heart organ itself were faded from prolonged exposure to the formaldehyde, a full color printout wasn’t necessary, and the digital model was printed using a gray plastic filament.
Being a model hobbyist, the colorless printout didn’t present a problem for Dr. Kuehn, who proceeded to hand-paint the model with more natural colors. The result was a durable replica of the original heart organ, which could be handled and examined by students in the classroom setting. Dr. Keuhn: “I used it in my lecture on the superficial heart, demonstrating it in class and letting students see it after class to go over the structural pathologies.”
Even before it was completed, news of the project traveled throughout the college and it wasn’t long before Gary received similar requests from other COMP faculty. One of those faculty was Chaya Prasad, MD, MBA, who recognized the potential of the technique for teaching pathology. Her initial request for digital models of a cancerous lung and uterine leiomyoma gave Gary an opportunity to refine his techniques even further. Gary Wisser: “We’re looking into adding more prongs to the original single-prong mount to increase stability. We’ve also done some experimenting with Photoshop to see if we can add more color to the 3D model and enhance the less detailed cutaway views with photographic images.” An example of this latter technique can be seen in the left hand image below, where Gary was able to integrate a higher resolution photograph of the kidney’s interior with the original 3D model.
As of November 2016, Gary has completed eight scans of diseased organs and tissues for Dr. Prasad. In addition to the kidney model, other scans will soon be added to WesternU’s EdMedia Repository at http://edmedia.westernu.edu
For more information about the heart scan and other pathology scans, contact:
Craig Kuehn, PhD, Professor of Anatomy, COMP at firstname.lastname@example.org
Chaya Prasad, M.D., MBA, COMP, Associate Professor of Pathology, COMP, at email@example.com
Gary Wisser, 3D Visualization Specialist, at firstname.lastname@example.org