Scientists have created a robotic device that safely guides itself through the delicate chambers of a beating pig's heart.
The surgical robot, whose motion was inspired by the way cockroaches skitter along walls, is able to navigate without any help from a doctor or anyone else, according to a study published Wednesday in the journal Science Robotics.
Surgeons routinely push a thin tube called a catheter through a patient’s blood vessels, allowing them to make repairs in the heart without resorting to traditional surgery. Could a robotic version find its own way, even with blood swishing in the way?
The robot would need an “optical whisker,” and researchers created one out of the catheter’s camera tip, said study leader Pierre Dupont, chief of pediatric cardiac bioengineering at Boston Children’s Hospital.
Just as cockroaches navigate along walls and rats reach out with their whiskers, the catheter maps its path through the heart, tapping periodically against the heart's valve and wall ever so lightly — with about the force of a stick of butter sitting in your hand, Dupont said.
The technology combines the camera's images with machine learning to interpret what tissue it's touching, and how hard it’s touching it.
“This robot is trying to walk along the wall of the heart until it gets to the valve,” said Dr. Uma Duvvuri, who heads a robotic innovation lab at the University of Pittsburgh Medical Center and wasn't involved in the new study. “That's a pretty exciting development, but this is still very, very preliminary.”
The robot isn't designed to replace a surgeon, Dupont said. Instead, he said it might free up a surgeon's time to focus on more difficult tasks, functioning like the autopilot system on an airplane. It could also reduce the time patients and medical staff are exposed to X-rays that currently are needed for navigation.
Dupont's team tested the robotic catheter in 83 procedures with live pigs in a lab. The device was able to find its target in 79 of the tests, on average taking about eight seconds longer than a doctor threading a catheter into place. But Dupont said the robotic catheter will learn, just like humans, and get better and faster with more practice.
The robot is still years away from being deployed inside an operating room, he added.
“The easiest part of autonomy in surgery is the technology,” he said. “The hardest parts are the politics, the regulatory” approval and legal efforts.
Russ Taylor, a medical robotics specialist at Johns Hopkins University, called the technology clever and the study “a significant achievement, but I wouldn't flag it as a breakthrough.”
Robots with different levels of autonomy have been used in surgery for radiation therapy and orthopedics, said Taylor, who wasn't involved in the new research. And Duvvuri pointed to studies with a robot that can stitch tissues together without human help.
While the new study focused on a potential heart use, Duvvuri said that adding sensing technology to catheters could have other medical uses, such as helping to diagnose risky growths in the colon.
Taylor agreed. “I see things evolving where the machine keeps undertaking more and more discrete tasks while working in partnership with the humans,” he said.