New Knot Technology Developed in China Improves Suturing Accuracy by 121% Even for Inexperienced Surgeons

Zhejiang University Team's Findings Published in Nature
Technology Enables Consistent Tension in Robotic Surgery Suturing
"Even Less-Experienced Surgeons Improve Force Control Accuracy by 121%"

Chinese researchers have developed a new knot that helps automatically adjust the tension required for suturing during robotic surgery. Experts say this technology enables suturing with the precision of skilled surgeons, even without complex sensors.

The photo is not related to the specific content of the article. Pixabay

According to the South China Morning Post (SCMP) on December 8 (local time), a research paper on the “smart knot” technology, which maintains consistent tension without complex sensors, was published by the convergence research team at Zhejiang University in the international journal Nature on November 27.

In surgical procedures, the suturing and knot-tying stage requires precise force control. If sutures are too tight, they can impede blood flow; if too loose, the wound may open. For this reason, advanced medical and robotics fields in China have been researching ways to precisely control and transmit force through robotic arms. In particular, for laparoscopic and robotic surgeries, where surgeons cannot rely on tactile feedback, mechanically replicating the sense of touch of experienced surgeons has long been a challenge.

Cai Shujun, the lead researcher and professor at Zhejiang University, explained in a university press release, “In open surgery, surgeons can directly feel the softness of tissues and adjust suture tension accordingly. However, in laparoscopic or robotic surgeries, surgeons operate the robotic arms via a screen, losing tactile feedback and entering a ‘force blind spot’ situation.”

SleepFuture suturing technology announced by the convergence research team at Zhejiang University, China. Nature

The core idea emerged during discussions among researchers from various fields. Yang Xuxu, a researcher in mechanical engineering and co-corresponding author of the paper, proposed utilizing the mechanical principle that “the tension at both ends of a string is always the same” by suggesting, “What if we create a slip knot next to the main knot in advance?”

The research team explained that “by creating an additional slip knot in front of the surgical knot, when the pulling force on the thread reaches a certain level, the slip knot automatically releases, precisely matching the required tension.” This mechanism prevents the knot from being tightened beyond a predetermined force.

According to the paper, the team succeeded in delivering steady force with up to 95% accuracy of the target tension by adjusting the knot-overlapping method and material properties. This slip knot remained stable for up to 32 days and, regardless of the pulling speed, transmitted only the preset force, functioning like a “mechanical fuse.”

In experiments, the suturing system named “sliputure” maintained a precise tension of about 1.3 newtons, similar to the force used when tying a shoelace. Under the same conditions, conventional robotic suturing tended to exert excessive force of 2 to 3 newtons, according to the researchers.

In experiments comparing recovery rates by suturing the organs of laboratory mice, the areas sutured with sliputure recovered to a healthy level by the fifth day after surgery, which was two days faster than with conventional methods. In laparoscopic suturing experiments on pig organs, the application of sliputure reduced tissue compression and deformation, and the knots remained uniform.

The paper stated, “Applying this mechanism enables even less-experienced surgeons to improve knot force control accuracy by 121%, allowing them to perform suturing comparable to skilled surgeons. This technology can serve as a training tool and also replace conventional sutures in resource-limited medical environments.”

Zhejiang University stated that this research has opened a new path for “mechanical intelligence” that does not rely on electronic sensors. The research team predicts that, since it can operate immediately even during power outages or network failures, the technology has great potential for use not only in deep surgeries but also in extreme environments such as deep sea, space, and underground.

This content was produced with the assistance of AI translation services.