Bioengineers at Boston Children's Hospital report the first demonstration of a robot able to navigate autonomously inside the body. In an animal model of cardiac valve repair, the team programmed a robotic catheter to find its way along the walls of a beating, blood-filled heart to a leaky valve -- without a surgeon's guidance. They report their work today in Science Robotics.
Touch-guided vision, informed by AI
The team's robotic catheter navigated using an optical touch sensor developed in Dupont's lab, informed by a map of the cardiac anatomy and preoperative scans. The touch sensor uses artificial intelligence (AI) and image processing algorithms to enable the catheter to figure out where it is in the heart and where it needs to go.
Biologically inspired navigation
Through a navigational technique called "wall following," the robotic catheter's optical touch sensor sampled its environment at regular intervals, in much the way insects' antennae or the whiskers of rodents sample their surroundings to build mental maps of unfamiliar, dark environments. The sensor told the catheter whether it was touching blood, the heart wall or a valve (through images from a tip-mounted camera) and how hard it was pressing (to keep it from damaging the beating heart).
A vision of the future?
Dupont says the project was the most challenging of his career. While the cardiac surgical fellow, who performed the operations on swine, was able to relax while the robot found the valve leaks, the project was taxing for Dupont's engineering fellows, who sometimes had to reprogram the robot mid-operation as they perfected the technology.
Materials provided by Boston Children's Hospital. Note: Content may be edited for style and length.