Summer student's EEG research continues to develop at ARL

October 28, 2015

By Joyce M. Conant, ARL Public Affairs

Story Highlights

  • Student's project focused on the development of a phantom head for testing electroencephalography headsets
  • Goal to design and fabricate a molded human head out of ballistics gel
  • Student's efforts helped tie together an inter-disciplinary team of ARL researchers to work together on a practical problem

Ben Burke's College Qualified Leadership, or CQL, internship at the U.S. Army Research Laboratory's Human Research and Engineering Directorate came to an end this summer when he returned to college at the University of Maryland, College Park, but his project at ARL continues to develop.

Burke's project focused on the development of a phantom head for testing electroencephalography, or EEG headsets. EEG is the process of measuring electrical activity on the scalp to determine brain function.

Burke, who is majoring in biological sciences with a possible minor in neuroscience, was mentored by Drs. W. David Hairston and Alfred Yu - both of whom are in ARL's Translational Neuroscience Branch.

"The goal of this project was to design and fabricate a molded human head out of ballistics gel. The mold is based on an MR (magnetic resonance) image of one of our lab members, with some of the facial features anonymized. This image was used to 3D print an inverse mold, which also contains a specially designed base containing wires to serve as internal electrical sites inside of the head," said Hairston. "Since ballistics gel is grossly similar to organic tissue in its conductance profile, the head can then be used as a test fixture with our EEG equipment either to test the equipment's function, model different sources of environmental noise and how it affects the equipment, or verify different kinds of algorithms that we use for processing or analyzing data."

Hairston said the team had to rely on collecting EEG data from a person. He indicated this is quite inconvenient for people as they have to sit still for long periods and they cannot predict what the signals will actually look like. So as a result, they started a long-term effort on developing a so-called 'phantom' device to replace the human head for testing equipment and algorithms and to serve as an 'ideal' platform.

So with that, Burke, along with his mentors, decided to try something different - develop a phantom device out of gelatin.

"My mentors and I chose to make the phantom head out of gelatin as it simulates the physical properties of the human head and can conduct electricity. We created the head by designing and 3D printing a mold and base combination, using a 3D printer from VTD [Vehicle Technology Directorate] for this step, and by instrumenting wiring through the base and extending into the head in order to send electrical current through it," said Burke.

Burke described the process in more detail and spoke of how he worked with variety of directorates within ARL to accomplish his goals.

"We experimented with various types of gelatin in order to determine the ideal gelatin. We chose to go with organic ballistics gelatin we received from SLAD [Survivability/Lethality Analysis Directorate] for our phantom head. I manipulated different concentrations of the ballistics gelatin, doping (adding) different amounts of salt to these concentrations to increase phantom head conductivity and lower electrical resistance in the gelatin," explained Burke.

Burke continued and explained his involvement with ARL's Weapons and Materials Research Directorate.

"We collaborated with WMRD [Weapons and Materials Research Directorate] during this stage, receiving help with the process of doping conductive filaments into the gelatin. We poured the gelatin into the sealed mold we have set up and, after letting it sit in a fridge overnight, we cracked open the mold in order to obtain our phantom head. The next stage of our project from here will focus on using synthetic ballistics gelatin, largely because it has a longer lifespan than the organic gelatin that we have been using so far," said Burke.

Hairston expanded on the involvement of others within ARL who were instrumental to the project.

"We worked with multiple groups across ARL's directorates," said Hairston. "SLAD researchers (John Polesne, Bill Mermegan and Mike Kilduff) provided ballistic gel for our testing, and served as a deep well of institutional knowledge on mixing and forming ballistic gel. Another group of SLAD researchers (Charles Kennedy, Patrick Gillich, Kevin Jubb) helped us acquire a CT scan of our finished product, which allowed us to accurately characterize the electrode placement within the mold. Dr. Randy Mrozek brainstormed with Ben about potential projects to pursue, and has provided his time and expertise to mentor Ben in fabricating new synthetic, conductive gelatins for the next generation of phantom heads. Mr. Geoff Slipher helped us set up test equipment for determining the electrical properties of these gelatins, in order to compare them to human skin."

Yu further explained Burke's contribution.

"Ben's specific contribution was to determine a more cost-effective and easy method for creating a phantom head that can serve as a workable solution in the meantime - one that even cash-strapped neuroscience labs can easily and reliably follow," said Yu. "We think this has the potential to become a standard device in the EEG labs across the world. In particular, he was working on the design and initial fabrication of a ballistics gelatin-based model with embedded wiring to simulate brain activity."

Burke said he enjoyed the opportunities he received and loved the exposure he got at ARL.

"My favorite part of the summer was getting exposure to various different programs at ARL. While I mainly focused on neuroscience, I also engaged in work that touched on different disciplines that also related to our work. I really am appreciative and thankful of the opportunity to work here this summer. Getting to work in world-class research facilities and with top scientists was a fantastic opportunity that most people my age do not get to experience, and I was very fortunate to have had this experience," said Burke.

Burke added, "I would like to thank my mentors for helping and teaching me this summer, as well as to ARL for providing me with the opportunity to work here."

Yu commended Burke on his accomplishments and said he was instrumental part of the team.

"We had been toying with this idea for a while, but did not have the impetus or manpower to just try it out. Ben did a great job of asking the right questions and working out the details via careful lab work," said Yu. "Without his efforts this summer, this idea would not have gone very far. Ben served as a critical motivator for pushing the project from an idea to a tangible product with real applications. His ability to work independently on a wide variety of tasks also gave us the leverage to go to other folks to ask for help and resources - Ben basically helped tie together an inter-disciplinary team of ARL researchers to work together on a practical problem."

 

Last Update / Reviewed: October 28, 2015