Now, here’s an unusual application for a 3D printer. For decades, researchers have looked for ways to manipulate the brain in order to determine how it changes as it learns or comes under the influence of drugs and other stimuli. Understanding how these influencers affect brain activity may lead to treatment of stroke aftereffects, such as loss of muscle control and aphasia (the loss of ability to talk, listen, read and write).
Dr. Robert Rennaker II, an Associate Professor at the Erik Jonsson School of Engineering and the School of Behavioral and Brain Sciences at the University of Texas, Dallas, has been investigating this area of neuroscience for years. One of the most important tools in support of his research efforts is 3D printing in his laboratory.
Rennaker must produce parts strong enough for lab testing, durable enough to assemble and absorb load impacts, and detailed enough to develop brain-machine interfaces to study how a brain responds to different stimuli. However, sending CAD files to a machine shop to manufacture these parts meant waiting weeks to receive the models, resulting in extended research delays. “One miniscule change would cost us innumerable time and significant expense. It was essentially impossible to conduct this type of research,” Rennaker said.
The inability to build prototypes quickly led Rennaker’s biomedical engineering department to purchase the Dimension 1200ES SST Elite model printer in June 2009. Rennaker found the printer through an online search. After looking into several printer models, he found that the strength of the ABS plastic used by the Dimension printer would satisfy the needs of his research projects. He can build the end-use parts because the 3D printed parts are so strong.
Dr. Robert Rennaker must produce parts strong enough for lab testing, durable enough to assemble and absorb load impacts, and detailed enough to develop brain-machine interfaces to study how a brain responds to different stimuli. He uses a 3D printer to develop his designs. Then, some of those 3D printed parts are injection molded or used for final machined parts.
Rennaker is currently working on a stroke project dealing with loss of motor functions in the motor cortex (the part of the brain that plans, controls and executes voluntary motor functions). Post-stroke, a patient often loses the ability to move a hand. Rennaker uses his research to simulate this disability with his lab subjects. The subjects place a paw in a hole with a wheel at the bottom, when the subjects rotate the wheel they are given a food reward. The device forces the subject to use its paw instead of its whole leg. The group is studying the effect of stimulating the Vagus nerve while performing the task in an attempt to facilitate and expedite recovery of function in the limb affected by the stroke.
The researchers hope that someday this patented Vagus Nerve Stimulation (VNS) technique will help human stroke victims recover faster and more fully. The 3D printers have been essential to the progress of this research project. “The printer has accelerated this important research by a factor of four or five, and it gives me the freedom to think outside the box. I am not constrained to incremental steps,” said Rennaker. “I can design an entirely new device and print it in a single day.”