Duke University, Class of 2025
Simulating and Building Low-Cost Ultrasound Transducers
This summer, my project was to simulate, build, and test three low-cost ultrasound transducers with 1.5 MHz, 3 MHz, and 6 MHz frequencies. The goal was to identify one or more that could be tested in the Sheybani Lab at the University of Virginia (UVA) to open the blood-brain barrier (BBB) in preclinical studies.
I used 3D-printed housings that were modified from Dr. Hong Chen’s study, and the pressures were first simulated in K-wave and then measured by scanning with a hydrophone.
I was able to create all three simulations, working transducers, and pressure maps. Although the simulation pressures didn’t exactly match the pressure readings from the map, the relative shapes and sizes of each plane (XY, XZ, YZ) correlated well, especially for the 1.5-MHz transducer. From the simulations, as frequency increased, the size of the focal zone decreased, ranging from 4 mm at 1.5 MHz to 1 mm at 6 MHz. We determined that the 1.5-MHz transducer’s large focal spot was ideal for testing to see if it could successfully open the BBB, and we achieved positive results.
Why were you initially interested in working with the Foundation?
As someone from Charlottesville, I was very excited to find such an interesting and impactful internship so close to home! Furthermore, the projects required skills that I recognized and wanted to improve on, such as 3D design and MATLAB software. I knew about the use of ultrasound for imaging, and I had seen how helpful it was for guiding a procedure on my wrist, so I was also extremely curious about how ultrasound worked. Shortly after starting as an intern, finding out about the entire branch of therapeutic ultrasound blew my mind.
What was the most important learning point of your internship experience?
If I had to pick, I would say when we went to the Focused Ultrasound Center at UVA because we finally saw how an ultrasound treatment looks in real life. Feeling the magnetic pull of the MRI combined with learning more about the science behind MR imaging techniques and focused ultrasound treatments put what we had read in papers to life. Additionally, throughout the visit we were able to ask questions – about the technology, the treatment process from both the engineers’ and the patient’s perspectives, how this new treatment affects people, and what it was like working at the Focused Ultrasound Center. The more I learned, the more curious I became about the potential of ultrasound and what is still left to discover with the technology.
Most importantly, we also got to hear stories from our mentors about what this treatment meant for the patients, and I was shocked to hear how involved my engineering mentors were in the process as they described patients becoming emotional walking out of the MR room from regaining control of their hands (this was particularly for the real-time treatment of essential tremor). The visit stuck with me as our mentors gave us an honest view into the field and what a career could look like as an engineer in focused ultrasound; the highs of the patient reactions, lows of challenges around insurance reimbursement, fascinating science, and daily tasks all confirmed my thoughts to continue to pursue engineering in the medical field as you can directly see your actions helping others.
Has your internship affected your career plans?
I was on the fence about whether to go fully into mechanical engineering or to stay on the biomedical and mechanical path, and after this internship, I do think that I want to stay involved in biomedical engineering. Medical technology is both incredibly interesting and feels more personal due to the direct positive impact advancements have on people. It was also interesting to find out that each of my mentors arrived at the field from slightly different backgrounds, so I felt less stressed in having to pick the one “correct” major. I saw that multiple majors could lead to the same destination if you were passionate about the field.
Additionally, I was worried that I wouldn’t have any patient interaction or that I would feel disconnected as an engineer, but after talking with and watching the daily activities of my mentors, I found this not to be true. Engineers could be involved in creating a treatment plan for the ultrasound devices in the Focused Ultrasound Center, testing and calibrating those devices, building their own devices for market, or working more in a lab setting at UVA to determine the best parameters of ultrasound for each treatment. Though I’m not sure if I want to pursue focused ultrasound as my career, I do want to keep the door open as the technology is amazing and there are plenty of opportunities to feel connected as an engineer in the field.
Ella joined the Foundation this summer through our partnership with Virginia Bio’s STEM2VA program.