What if your next operation is planned and performed by a robot? A team from Johns Hopkins University is working to make this idea a reality.
The concept of robot-assisted surgery is not new: several systems have already been developed and are being used to treat patients. One example is the da Vinci surgical system, a laparoscopic device with robotic arms that are controlled remotely by a surgeon. This system is not autonomous – the robot does not perform any surgical tasks alone.
Other robotic systems with higher levels of autonomy, such as the TSolution One, have also been developed®which uses a robot to precisely cut bone according to a predetermined plan.
Existing autonomous robotic systems are widely used to support operations involving hard tissues, such as bone piercing for hip or knee implants. But these systems have not been used for soft tissue surgeries that pose unique challenges, such as taking into account unpredictable tissue movements that occur when the patient is breathing or limiting the size of surgical instruments.
NIBIB-funded researchers are now developing an autonomous robot that can perform bowel surgery with minimal help from a surgeon. Moreover, the robot was superior to expert surgeons compared to preclinical models. A study describing the development of this robot, which shows the first known autonomous laparoscopic soft tissue surgery, was published recently in Scientific work .
“Surgical outcomes are highly dependent on the surgeon’s skills and experience, and even a missed suture during bowel surgery can lead to internal leakage and infection,” said Moria Bitman, Ph.D., program director in Discovery’s science and technology department. National Institute of Biomedical Imaging and Bioengineering. “This preclinical work is an important step towards autonomous robotic soft tissue surgery, which can provide increased efficacy and safety in human patients, regardless of the surgeon.
The robot, called STAR (for Smart Tissue Autonomous Robot), was developed by Dr. Axel Krieger and his colleagues at Johns Hopkins University. So far, the robot has been developed to perform an intestinal anastomosis – where two parts of the small intestine are sutured together to form a single, continuous section – under the supervision and guidance of a surgeon. Krieger explained how the robot performed the procedure: After the surgeon manually exposed the edges of the tissue, STAR took images and developed a suture plan based on the shape and thickness of the tissue. Once the human operator has approved the plan, STAR independently sews the fabric together. If the tissue deforms or moves beyond the set threshold, STAR asks the surgeon if a new surgical plan needs to be created. This process is repeated until the robot completes the entire procedure.
“By incorporating new suturing tools, imaging systems, machine learning algorithms and robotic controls, the STAR system is equipped to meet the challenges of autonomous laparoscopic soft tissue surgery,” Krieger said. “STAR can visualize a surgical scene, generate a surgical plan, and then execute those plans with high accuracy and precision. However, he noted that STAR is not intended to replace surgeons. “Autonomous robots, such as STARs, are designed to be included in the surgical workflow with surgeons, improving the performance of precise, repetitive tasks and ultimately improving patient-to-patient surgical sequence.”
To assess how well STAR performed compared to expert surgeons, the researchers used “phantom” intestinal tissues as a model system. Synthetic small intestine is mounted on a linear stage, which is programmed to move back and forth, which simulates respiratory movements that will occur during surgery. In addition, during these experiments, the phantom tissue was randomly rotated and deformed, forcing the STAR or surgeon to pause, regroup and complete the procedure, he said. STAR performed the procedure on phantom tissues five times, and four surgeons performed the procedure in two different ways – twice using traditional manual laparoscopy and twice using a different robot-assisted system.
Compared to expert surgeons, STAR had fewer errors and was more consistent in the distance and depth of sutures. In addition, when the researchers passed viscous fluid through the resected phantom intestines, they found that the flow was the most laminar (smooth and streamlined) in the tissues reconstructed by STAR, showing a higher quality anastomosis than those performed by experienced surgeons.
Finally, the work of STAR was appreciated in a large animal model. An intestinal anastomosis was performed on five pigs. In four of the animals, the procedure was performed by STAR, and in the fifth animal, the procedure was performed by traditional manual laparoscopy. Like the phantom experiments, STAR made fewer mistakes than the expert surgeon. In addition, when the researchers analyzed how well the resected bowels healed seven days after surgery, there was no visible difference in wound healing between the two different surgical methods.
“Our results show that STAR is more consistent and accurate than expert surgeons in performing suturing tasks,” Krieger said. He noted that their findings demonstrate the potential of autonomous surgical robotics to democratize surgical care – which could lead to more predictable and consistent results for patients.
“While many may be hesitant about whether the machine will perform a specialized task that is traditionally performed by humans, robotic systems have the potential to improve patients’ outcomes in the medical setting,” Krieger said. “Just as the public has embraced the gradual introduction of cruise control, lane assistant and self-parking in cars – which will eventually lead to self-driving cars – I think we will see similar advances in medical robotics. ”