Researchers say the aim of the supervised autonomous robot system is not to replace surgeons, but to improve results by complementing human skills with enhanced vision, dexterity, and machine intelligence.
Image credit: Children's National Health System
The team, from the Sheikh Zayed Institute for Pediatric Surgical Innovation, Children's National Health System, Washington, DC, describes the Smart Tissue Autonomous Robot (STAR) and how it outperformed human surgeons operating on soft tissue in a Science Translational Medicine paper.
They tested STAR against manual surgery, laparoscopy (keyhole surgery), and robot-assisted surgery with the da Vinci Surgical System on dead tissue and also in a procedure called "anastomosis," which involved connecting the tubular loops of the intestines in live pigs.
The researchers note that the "supervised autonomous surgery offered by the STAR system was superior" to the other methods.
STAR is a supervised robot that effectively removes the surgeon's hands from the procedure, and instead, the surgeon supervises the robot's autonomously planned and performed stitching or suturing.
Soft tissue is tissue that connects, supports, or surrounds organs and other body structures like tendons, skin, fat, muscle, nerves, blood vessels, and ligaments.
In the United States alone, over 44.5 million soft tissue surgeries are performed every year; 1 million of these are for anastomosis.
'Not to replace, but to complement human surgeons'
In tests on dead and live tissue, the STAR system outperformed the other methods on a number of critical measures.
These measures included consistency of suture spacing (which helps to promote healing) and the amount of pressure that the joined tissue can withstand before leakage occurs - an area of significant potential complication in anastomosis.
Mistakes requiring needle removal were also minimal for STAR, and the reductions in tube diameter (lumen reductions) in the STAR surgeries were also within the acceptable range, note the researchers.
However, the anastomosis using STAR took longer to complete than a manual procedure - 35 minutes as opposed to 8 minutes. But the researchers note that the robot took about the same time as the average for keyhole surgery, which can range from 30-90 minutes for anastomosis, depending on complexity.
Surgery on soft tissue is a difficult task for robots because it deforms and moves around unpredictably when touched, requiring the surgeon to make constant adjustments. But, by bringing together tools for "suturing as well as fluorescent and 3-D imaging, force sensing, and submillimeter positioning," the researchers have managed to make their robot overcome this difficulty.
For example, the robot's tracking system combines near-infrared fluorescent (NIRF) marking with a 3-D "plenoptic camera" to create 3-D images of the target tissue. This captures a series of small images from different angles, focusing on selected points.
These images are then processed by special software to enable accurate, uninhibited tracking of tissue deformation during the surgery.
Another piece of software, an intelligent algorithm, combines with the tracking system to guide - and autonomously adjust in real time - the surgical plan as the tissue moves around and changes.
A video from Science further explains how the robot works.
Senior author Dr. Peter C. W. Kim, a pediatric surgeon and vice president of the Sheikh Zayed Institute, says the intention is not to replace surgeons, but to improve results by complementing human skills with enhanced vision, dexterity, and machine intelligence.
"Our results demonstrate the potential for autonomous robots to improve the efficacy, consistency, functional outcome and accessibility of surgical techniques."
Dr. Peter C. W. Kim
The team now plans to make the tools even smaller and improve the sensors so the technology can be used more widely. Dr. Kim says they hope that with the right partner, some or all of the technology will be ready for clinical use in the next 2 years.