Ultrasound has been a trusted tool in medicine for decades, allowing doctors to peek inside the human body without a single incision.
If Zhen Xu hadn’t annoyed her lab mates, she might never have made a breakthrough in liver cancer treatment.
As a PhD student in biomedical engineering at the University of Michigan in the early 2000s, searching for ways to help doctors remove diseased tissue without invasive surgery. She explored using high-frequency sound waves—ultrasound—to mechanically break up tissue and she tested her ideas on pig hearts.
While ultrasound is normally inaudible, Xu’s experiments used such a powerful amplifier that it disturbed her fellow researchers. “Nothing had worked anyway,” she recalls. To keep the peace, she decided to increase the ultrasound pulse rate, moving the sound out of the range of human hearing.
The new approach was not only quieter for her colleagues but also more effective on living tissue than her previous methods. Within a minute, a hole appeared in the pig heart tissue. “I thought I was dreaming,” Xu says. Today, she is a professor of biomedical engineering at the University of Michigan and a pioneer in ultrasound-based therapies.
While ultrasound is generally inaudible, Xu’s powerful setup created enough noise to bother her lab mates. To address their complaints, she increased the ultrasound pulse rate, moving the sound out of the human hearing range.
Surprisingly, this adjustment made the treatment not only quieter but also significantly more effective on living tissue.
Within just one minute of applying the ultrasound, Xu watched a hole form in the pig heart tissue—a moment that would mark the beginning of a revolutionary approach to non-invasive liver cancer therapy. Today, as a professor of biomedical engineering at the University of Michigan, Xu continues to push the boundaries of medical innovation.
When most people hear the word ultrasound, they immediately think of pregnancy scans that show the first images of a developing baby. However, ultrasound technology goes far beyond that—it’s a powerful medical tool used for both diagnosis and treatment.
Ultrasound works by using a handheld device called a transducer, which sends high-frequency sound waves into the body. These waves travel through tissues and bounce back when they hit different structures inside. The returning echoes are then captured by the device’s sensors and converted into electrical signals, creating detailed images of what’s happening beneath the skin. This non-invasive process allows doctors to view internal organs, muscles, and other tissues in real time.
In recent years, scientists have discovered that ultrasound can do more than just take pictures—it can also treat diseases like cancer. By focusing ultrasound waves on a specific area of a tumor, doctors can generate enough energy to destroy cancerous cells without the need for invasive surgery. This technique, known as focused ultrasound therapy, offers a promising alternative for patients seeking precise, pain-free treatments with minimal recovery time.
