“What do you want to be when you grow up?”
It’s a question commonly posed to children. Responses vary, and adults often expect them to be narrowed down to one occupation, such as “doctor” or “teacher.” But Angel Peterchev, PhD, professor of psychiatry and behavioral sciences, is living proof that career aspirations can be as expansive as one’s imagination allows. He’s an electrical engineer, neuroscientist, inventor, researcher, and physicist—and a teacher.
LEGO Sets Provide an Early Spark for this Inventor
Peterchev’s tug toward inventions and electrical engineering began at the young age of five, when his grandfather showed him how to turn on a lightbulb by connecting it to a battery. From that point on, Peterchev recalls wiring his own batteries and putting them in different toys, including LEGO. “I loved to tinker, take things apart, and build from the parts,” Peterchev said. “I was six years old when I started saying I wanted to be an inventor.”
“I was six years old when I started saying I wanted to be an inventor.”
— Angel Peterchev, PhD
In second grade, Peterchev built his first remote-controlled LEGO robot with lights and moving arms and wheels. When he presented it at a school technical show, his teachers were so blown away, they suspected his parents had helped him—but he’d done it all on his own.
“Everybody has their calling and passion, and it develops at different stages in life,” he emphasized. Peterchev, though, just happened to discover one of his primary passions, electrical engineering, extremely early in life.
Just a couple years later, in fourth grade, Peterchev discovered his second career aspiration: becoming a physicist. Though he had not yet learned about physics in school, he’d seen a TV show about it that deeply resonated with him. These two interests stuck with him throughout elementary, middle, and high school, and eventually as he transitioned into post-secondary education.
Electronics at Harvard & Berkeley
Born and raised in Bulgaria, Peterchev moved to the United States at 18 to attend Harvard University on a university scholarship, where he earned dual degrees in physics and electrical engineering.
While studying these disciplines, he developed a third passion: the study of the brain.
Similar to how he discovered physics, Peterchev had come across a novel a few years prior that piqued his interest in neuroscience. “I had read a science fiction book about someone who developed a device to transmit thoughts. And I remember thinking, ‘It’s so cool that the brain is an electric organ that can interact with electromagnetic fields,’” Peterchev said. “And of course, thought transmission is science fiction. Nonetheless, it was really a fascinating concept that stayed in the back of my mind.”
When it came time to pick a core curriculum class his freshman fall, Peterchev naturally gravitated toward a class titled “Vision and Brain,” where he was reminded of his fascination with the brain, particularly how it works like a circuit. While he enjoyed the class, he tucked away some of the concepts he’d learned and continued with his electronics research.
After graduating in 1999, he went on to University of California, Berkeley to complete a master’s degree in 2002 and a PhD in 2005, both in electrical engineering.
Transitioning into Psychiatry & Neuroscience
In his doctoral program, students were required to take courses outside their focal area, so Peterchev decided to revisit one of his previous intellectual interests, picking up a minor in cognitive neuroscience. In a neuroscience seminar, students were asked to analyze a specific topic. Peterchev chose transcranial magnetic stimulation (TMS), which tapped into his expertise in electronics and physics.
Peterchev describes TMS as “a way to non-invasively stimulate and activate the brain using pulsed magnetic fields applied through a wand you place on the head.” The magnetic coil is placed over a part of the scalp and carries a brief electrical current, creating a magnetic field and an electrical stimulus in the brain. “It reminded me of that science fiction novel about sending electromagnetic fields to the brain,” Peterchev described.
After the seminar, Peterchev assisted one of his professors on a TMS project, modifying a device to aid in the research. It was a side project while he continued his dissertation work on microprocessor power supplies.
Upon graduation, Peterchev had several offers from Silicon Valley technology companies. He had internship experience in Silicon Valley and plenty of hard skills in power electronics to pursue a job in technology and make a six-figure salary. But despite these lucrative offers, he chose instead to pursue post-doctoral studies in the psychiatry department at Columbia University—a rather unusual path, considering his previous studies.
Non-invasive brain stimulation was Peterchev’s newly-found passion, and he’d realized it was an area of study that would uniquely connect his seemingly divergent academic pursuits. “It really combined my interest in electronics, physics, and the brain,” he said. “And I was fascinated by the potential for therapeutic applications.”
Decades later, Peterchev’s primary faculty appointment continues to be in psychiatry, in Duke’s Department of Psychiatry & Behavioral Sciences. He acknowledges his uniqueness in the department but notes that people studying engineering and medicine are becoming increasingly common nowadays.
Advancing TMS Technology for Better Experiences & Outcomes
The beauty of TMS is its potential to heal neurological and psychiatric disorders non-invasively, without drugs or surgery. During treatment, patients remain awake, seated in a comfortable recliner for three to 20 minutes at a time. Patients undergo several sessions, similar to other forms of therapy, and the frequency and duration of treatment differs per case.
Compared to medications or more invasive electrical stimulation methods, TMS is unique because of its relatively few side effects combined with high localization. TMS has been cleared by the FDA for treatment of depression, anxiety, obsessive compulsive disorder (OCD), smoking addiction, and some migraines. Other applications currently being explored include treatment for pain, strokes, schizophrenia, movement disorders, and post-traumatic stress disorder, or PTSD.
Peterchev leads the Brain Stimulation Engineering Lab (BSEL), where his team is working on three main areas. The first is building better devices. The lab team has made significant advancements, including designing a quieter TMS device.
“The coil sitting on your head is like a loudspeaker. And the clicking of the TMS device can sound almost like gunfire,” Peterchev said. “In persons with PTSD or autism, it may be too much sensory stimulation. Also, the brain is activated by auditory signals, so we’re making it more cleanly focused on the response to the magnetic field.”
Peterchev’s team is also partnering with experts in computer vision and artificial intelligence in Duke’s Pratt School of Engineering to create comfortable, accurate, and cost-efficient camera systems that allow precise targeting of the coil relative to the brain.
“Roughly, we know there are some neurons activated under the coil, but there are so many things we don't know about this response. If we know more details, it will empower us to fine-tune, individualize, and optimize these treatments.”
— Angel Peterchev, PhD
BSEL’s second focus is to better understand the biophysics of stimulation and refine parameters such as the magnetic pulse shape, strength, and frequency, which requires understanding what’s occurring inside the brain. “Roughly, we know there are some neurons activated under the coil, but there are so many things we don't know about this response,” Peterchev said. “If we know more details, it will empower us to fine-tune, individualize, and optimize these treatments.” To study the effect of the stimulation parameters, the lab uses supercomputers to run detailed models of the brain.
Thirdly, the team and their collaborators are running experimental studies with healthy volunteers—including Duke undergraduates—and patients in psychiatric clinical studies to observe whether and how the technology works.
Another Passion: Sharing His Expertise
As a professor in Psychiatry & Behavioral Sciences with additional appointments in the Departments of Biomedical Engineering, Electrical and Computer Engineering, and Neurosurgery, Peterchev is also involved in teaching at Duke. This semester, he’s teaching a class on power electronics. Many of his former students have gone on to work at companies like Apple and Tesla. In 2018, he taught a student who was part of the Duke team that set the Guinness world record for the most efficient electric vehicle.
“This student said to me, ‘Professor, the things you taught me in class, I used in the electronics I made for the vehicle,’” Peterchev recalls. “I really delight in the opportunity to educate engineers to do better and go out there and make their own contribution.”
Aside from instructing engineering students, Peterchev also serves as the director of the Duke TMS course, a three-day intensive course offered four times a year. Clinicians and researchers come to Duke from all over the world to learn about the background and best practices of TMS.
Although it might be puzzling to some, Peterchev has no regrets about his decision to pursue academia instead of Silicon Valley.
“I love having the opportunity to train and mentor students who go onto their careers and do fascinating and important things to help the world.”
— Angel Peterchev, PhD
“There’s the intellectual freedom, but there’s also interactions with brilliant people like my colleagues and students, and physicians and researchers,” Peterchev said. “And I love having the opportunity to train and mentor students who go onto their careers and do fascinating and important things to help the world.”
Solving Weighty Problems Requires Diverse Perspectives
As Peterchev continues to teach future generations of scientists and generate research to develop and enhance therapeutic treatments, he remains hopeful about his contributions to non-invasive brain stimulation moving forward. “That said, I keep an open mind about other research areas,” Peterchev said. “After all, I did a doctorate on microprocessor power supplies and now I’m power-supplying brains.”
Peterchev stresses the importance of a multidisciplinary approach in solving weighty problems. “I hope my background and trajectory illustrates that the problems we face are typically very multidisciplinary. They underscore the importance of having people with different backgrounds, training, and experiences to work together on significant challenges,” Peterchev said. “All these contributions are necessary to build upon this complex structure. Each of us is working one brick at a time.”
“I hope my background and trajectory illustrates that the problems we face are typically very multidisciplinary. They underscore the importance of having people with different backgrounds, training, and experiences to work together on significant challenges.”
— Angel Peterchev, PhD