Advancing ultrasound technology

Timothy Bigelow and Grant Riesberg
Timothy Bigelow and Grant Riesberg(right)

Combining his interests in the medical and engineering fields, Grant Riesberg, sophomore in electrical engineering, is gaining valuable industry insights as an undergraduate research assistant. Riesberg is working with Assistant Professor of Electrical and Computer Engineering Timothy Bigelow to advance the technology and application of ultrasound therapy.

Bigelow’s method of treating cancer through ultrasound therapy is based on the desire to kill cancer cells without having to surgically remove them. Using a very high-frequency range of around 1.1 megahertz, small bubbles are created in a piece of tissue, where they violently collapse as high-amplitude acoustical signals or loudness is coupled into the region. The approach, called histotripsy, allows targeted cancerous tissue to be turned into a paste-like substance while surrounding untargeted tissue is left unharmed.

Bigelow says ultrasound histotripsy, which he first heard about at a conference, is not new to the science world. His ambitions are to improve the technology so that it can be used in the medical industry. Knowing that these improvements would require a variety of contributors, Bigelow hired several undergraduates, including Riesberg, to work on various stages of the project.

Riesberg, who was looking for a project to fulfill the requirement for the First Year Honors Mentor Program, was immediately intrigued when he came across Bigelow’s research opportunity.

“The research is a mixture of electrical engineering and mechanical engineering with some legitimate medical implications, so I thought it would be perfect for me and a great way to begin my research at Iowa State,” Riesberg explains.

He has been working in the lab two to four days a week since last fall, making considerable headway into a notion Bigelow conceived: heating the tissue prior to using histotripsy to mechanically destroy the tissue.

ultrasound cavities
Cavities formed by ultrasound experiment

Using animal meat purchased from the local Fareway, Riesberg aims ultrasound waves on to the meat’s tissue. He has found that delivering a low-amplitude sound pulse before the higher pulse results in more precise cavities. “The goal of Grant’s research is to attempt to optimize the procedure to get very clean and precise targeted regions,” says Bigelow. Riesberg’s contributions will help Bigelow share this fresh approach to ultrasound therapy.

Riesberg says his laboratory work has been challenging, yet equally rewarding. “It took me a while to catch onto all the technical skills needed to work with the equipment,” he explains. “But, I really enjoy the independence in completing the research, and more importantly it really boosts my self-confidence of my ability to do new things I’m not used to doing.”

Riesberg-ultrasoundAs an added benefit, the project has given Riesberg some insight into where he would like to take his career. The combination of engineering and medical applications has strengthened his interest in pursuing a pre-med path, with hopes to become a physician. He has also realized what he doesn’t want to do: “Working in research is great for my college years because it gives me insight into working at a real job, develops lab skills, and instills confidence, but I know now that a job in research isn’t for me,” says Riesberg. Riesberg hopes that his involvement in the project could lead to more extensive research with Bigelow, possibly within his future research on brain cancer treatments.

Regardless of whether or not he works with Bigelow, Riesberg says he will definitely be scouting new research opportunities on campus. “The way I look at it is that these opportunities are an all around win,” adds Riesberg. “Working in the labs develops critical skills, work ethic, looks great on resumes, and is a paid job all in one.”