October 3, 2011

Pietro Valdastri

Bioengineer builds robotics to make medical procedures easier

Pietro Valdastri (John Russell/Vanderbilt)

The prospect of a colonoscopy is about as unwelcome as a root canal, so it’s no surprise that it’s difficult to convince people to get regular screenings for colon cancer. But what if you could replace this uncomfortable procedure by swallowing a robotic capsule the size of a multivitamin?

On the first day of classes, Assistant Professor of Mechanical Engineering Pietro Valdastri’s office was full of boxes and his lab was “almost an empty room.” Valdastri, his wife and their 1-and-a-half-year-old daughter arrived in Nashville from Pisa, Italy, just three weeks earlier, and he was still settling in.

Valdastri came to Vanderbilt from the Scuola Superiore Sant’Anna in Pisa, where he earned his Ph.D. in biomedical engineering and went on to become an assistant professor of industrial bioengineering. He earned his undergraduate degree in electrical engineering from the University of Pisa.

“[rquote]My real focus, from the beginning of my studies, was to do something related to medicine but from a technical, engineering point of view,” he said.[/rquote] His lab, the STORM (Science and Technology of Robotics in Medicine), will pursue the development of capsule robots to aid in the detection and treatment of colorectal disease and the development of robotic tools for single-incision laparoscopic surgery.

Endoscopic capsule cameras have been used in the United States for about a decade, but because they are passive devices, they haven’t been able to replace colonoscopies completely. Valdastri hopes to change this with a capsule robot that not only carries a camera, but also can stop, change direction, look around and even take samples.

An early version of this device looked like a cross between a Swiss Army knife and an insect: bristling with instruments and 12 tiny legs to hold the intestine open and crawl through, taking samples and wirelessly transmitting images to doctors. “It was pretty effective, but the problem was that it requires a lot of energy to work and the parts are really fragile.” So Valdastri and his team turned to magnets to provide locomotion.

The next capsule carried a strong magnet that Valdastri could manipulate with another magnet outside the body. A bright light illuminated the capsule within the body, so Valdastri’s team could track it as it moved through the body and see how it responded to the magnetic steering controls. However, the capsule could get stuck in the folds of the intestine – a problem that doctors currently avoid by inflating the intestine with air during a traditional colonoscopy.

He calls his current capsule a “front-wheel-drive colonoscope.” This model can’t be swallowed and still requires a cord – through which doctors can thread their biopsy tools and an air supply – but the cord is much thinner than the traditional semirigid endoscope. And because the camera is pulled rather than pushed from behind, it’s more comfortable – or at least less uncomfortable – for the patient.

“This really has the potential to replace flexible colonoscopy,” Valdastri said. The next step is for him to apply for an NIH grant to translate the technology for clinical trials.

Two wireless projects in the works are swallowable, magnetically controlled capsules that can take biopsies and apply clips to intestinal bleeds, both procedures that currently require an endoscope. Valdastri hopes to scale down the biopsy capsule even further for diagnosing conditions such as celiac disease in children.

Valdastri’s other research interest is laparoscopic surgery. Currently, laparoscopic surgery requires at least three incisions – one for the camera and two for the instruments. Valdastri has developed a capsule camera with a very thin cord that can pass through one of the instrument incisions. Using a magnet outside the body, Valdastri can manipulate the orientation of the camera, providing a panoramic view of the gastric cavity. The next step is to develop a way for robotic instruments and the camera to share one incision.

“[lquote]The idea is to have a complete surgery from a single entry point,” he said.[/lquote]

While many of us dream of going to Tuscany, Valdastri wanted to see the world. He will miss the beaches near Pisa, but he’s ready to embrace Nashville. Sitting on top of one of his boxes of books is an illustrated guide to American college football.

“I was introduced by a colleague of mine because in Italy we don’t have it,” he said. “First I’m studying the rules, but I like it.”

He chose to come to Vanderbilt because of its collaborative environment and access to the medical center.

“My dream is to have some device made by my research used in medical practice,” Valdastri said. “I really want to come to the patient.”

Watch video of Valdastri’s presentation at the TEDMed Conference in October 2011.

See the complete list of new faculty for 2011-12.