Ask the Experts: Tranquillo on brain switches
Assistant Professor Joe Tranquillo
Posted: April 21, 2011
LEWISBURG, Pa. — Joe Tranquillo, an assistant professor of biomedical and electrical engineering, talks about brain "switches" and how students have used engineering skills to solve medical and mechanical problems. || Faculty snap talk video
Q: Your research focuses on the dynamic network of "switches" in the brain and how they control basic movements and decision-making. What are brain switches and how do they work?
A: Researchers have viewed the brain in a variety of ways throughout history. At one point, the brain was thought of as an elaborate cooling mechanism and nothing else. It wasn't even thought to be part of consciousness or intelligence. When we went through the Industrial Revolution, there was an analogy made that our brains were just complicated machines. During the electronics revolution, it was thought that our brains were like computers. And right now, many think of the brain as a big network. In fact, I helped organize a colloquium series this past year to explore how these views have shaped the way we view our minds and identities.
In thinking of the brain as a network there has been an enormous focus on the neural code, the language neurons use to send messages to one another. An often overlooked problem is that this same code is also selectively turning on and off different areas of the brain. This is the idea behind neural switches. When we study the structure of the brain, each neuron is connected to about a thousand other neurons. But only a small percentage of your brain is on at any one time. So it's not enough to only know the network or what the code looks like. We also have to know how that code selectively turns on different areas of the brain at the same time.
Q: A group of students in your biomedical signals class developed a system to move a motor with brain power. How does this device work?
A: The students were able to get a motor to move based on brain signals. The way that this works is that there are regions in your brain that become more active when you do certain tasks. You can record this activity with electrodes. The information in these signals is similar to what you would be able to learn from a distance, like if you are in a blimp above a crowd in Bucknell's football stadium. You would be able to tell if the right side of the crowd cheered or if the left side cheered, but you wouldn't be able to tell why they were cheering, and you wouldn't be able to hear their individual conversations.
What the students did specifically was put electrodes on their vision centers on the surface of the scalp. So if they had their eyes open or closed, they were able to make the motor move. The students also pulled out another signal from the brain to make the motor move left or move right. One of those students went on this past year to refine the system to allow for imagined movements to control the motor.
Q: Bucknell's biomedical engineering majors must complete a senior design project in which they partner with medical professionals at Geisinger Medical Center to design and develop medical devices to solve real-world problems. What are some of the benefits of this partnership?
A: There are benefits for Bucknell and for Geisinger. Geisinger is at the leading edge of healthcare, and they have physicians who enjoy pushing the boundaries of what is possible. They have ideas, but they are not trained as engineers or designers, which is where our students come in. Our students take these ideas and develop them with the help of Geisinger's world-class experts, faculty mentors and Bucknell's Product Development Lab. All of those people are part of a big team, but the students are driving that team.
From Bucknell's point of view, the partnership with Geisinger allows our students to focus on all aspects of the design process, most importantly identifying real problems. Our students are going to be biomedical engineers when they graduate. Like all biomedical engineers, they will have an enormous diversity of technical skills. But what will set them apart is that they will speak the language of the medical community and be able to look for and solve real clinical problems.
Q: What are some examples of projects that Bucknell students have developed with Geisinger professionals?
A: One example is the zebrafish washing device, which some of my students developed four years ago. Zebrafish have similar brain chemistry to humans and are used to screen for drugs. Technicians create a mutation in the zebrafish and then inject different drugs in them to see how the fish respond. The way it was done in the past is that technicians would test for thousands of compounds one at a time. They would have to go in and suck out the compounds by hand and then go in and put a new compound in. The group of students from Bucknell as their senior design project created a chamber with a lid that allows you to fill it up with a solution, wash it and fill it back up again in a very short time period. What used to be a 30-minute process is now a 15-second process. The device is now patented with the students and myself listed as inventors.
A second example is from last summer, when two of my students collaborated with Dr. Frank Gilliam, director of neurology at Geisinger and a national leader in the field, to develop a novel type of individual electrode casings for the monitoring of brain-waves. Often, neurological patients are monitored for long periods of time while going about their daily business. The current technology is to wrap their entire head in gauze to keep the electrodes stable. Aside from being unattractive, it makes reapplication or adjustments difficult. The students played a key role in identifying the problem and then went on to make and then validate their design. The work was presented by the students at the annual Biomedical Engineering Society meeting last year, and Geisinger will be trying the electrodes on a real patient next week.
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