Pictured: The robot performs laparoscopic surgery on the soft tissues of pigs without human help
Wen 丨 Academic Headlines, Author 丨 XT, Editor 丨 Kou Jianchao
In recent years, the demand for surgical robots in the medical market has continued to grow, and many giant enterprises at home and abroad have laid out the surgical robot market, and the monopoly of da Vinci surgical robots has gradually been broken. Driven by capital, surgical robots have made new progress in technology, and thoracic and laparoscopic surgical robots have gradually matured.
The endoscopic surgical robot is known as the "aircraft carrier in the field of medical devices", which is one of the research and development directions of the current surgical robot field with extremely complex systems, extremely difficult technology, and high clinical and commercial value. Especially in intraperitoneal surgery, the operation is extremely difficult due to limited access and visibility of the target tissue, coupled with phantom interference caused by respiratory movements.
Recently, a research team from Johns Hopkins University designed a smart tissue autonomous robot STAR, which successfully completed a soft-tissue laparoscopic operation on a pig without human guidance.
The study, titled "Autonomous robotic laparoscopic surgery for intestinal anastomosis," was published in the scientific journal Science Robotics.
The study achieved the enhanced autonomy required to perform robotic laparoscopic small bowel anastomosis using an intelligent tissue autonomous robot (STAR) and the ability to perform enhanced total anastomosis autonomy under laparoscopy, marking an important step towards fully automated human surgery.
Axel Krieger, one of the study's authors and an assistant professor of mechanical engineering at Johns Hopkins University's White School of Engineering, said: "Our findings suggest that we can automate one of the most complex and delicate tasks in surgery – reconnecting the two ends of the gut. STAR performed surgery on four animals, which was significantly better than doctors performing the same surgery. ”
The first autonomous surgical robot to perform anastomosis in soft tissues
Surgical robots have been developed for many years, but most of them are mainly auxiliary surgical systems, such as the da Vinci surgical robot at the world's cutting-edge level, which is controlled by surgeons to assist in surgery, although the system has extremely high precision, but still faces considerable challenges in achieving autonomous surgery.
Autonomous soft tissue surgery requires surgical robots to have accurate and reliable imaging systems to detect and track target tissues, and also needs to consider factors such as the increase in complexity brought by soft tissue deformation to surgery, which requires higher robot systems. Laparoscopic surgery is a typical application scenario, which is extremely difficult due to the limited access and visibility of the target tissue, coupled with the artifact interference caused by respiratory movements.
In surgery, anastomosis happens to be a suitable scenario for examining autonomous robotic surgical systems for soft tissue surgery. The purpose of this procedure is to connect the two broken ends of the soft tissue and restore the continuous physiological structure, such as gastrointestinal anastomosis, fallopian tube anastomosis, tendon anastomosis, etc. Technically, it involves the approximation and reconstruction of the cavity structure, and the operability and reproducibility of the operation are extremely demanding.
Although existing autonomous surgical robots have made significant progress, most systems still show low autonomy and high dependence on doctors in complex tasks.
In the study, Axel Krieger et al. designed an enhanced autonomous STAR system for laparoscopic surgical scenarios, equipped with specialized suture tools and state-of-the-art imaging systems. The imaging system uses near-infrared labeling to track the start and end points of the suturing process of the target tissue, and has a strong robustness to the occlusion of blood and thin tissues during the operation, and the autonomy and surgical accuracy of the system are enhanced.
Figure | Enhanced autonomous laparoscopic soft tissue surgery (components of the A: STAR system, including medical robotic arms, driven surgical tools, and dual-channel NIR and 3D structured light endoscopic imaging systems; B: Control architecture of STAR's enhanced autonomous control strategy)
Connecting the two ends of the intestine is arguably the most challenging step in gastrointestinal surgery, requiring surgeons to suture the intestine with precision and consistency, and even the slightest hand tremor or misplaced sutures in surgery can lead to leakage of intestinal endocrine and catastrophic complications for patients.
The researchers used STAR to perform in vivo laparoscopic autonomous surgery on the pig's small intestine. Before the operation, the operator initiates STAR through a graphical user interface, and the system autonomously generates the suture algorithm and implements the suture task. During the suturing process, the operator fine-tuns the suture steps via the GUI before STAR performs the stitching plan, but much of the workflow is done autonomously.
During laparoscopic surgery, the operation is made more difficult because the movement of the pig's breathing and other tissues leads to the movement of the tissues targeted for surgery. To do this, the researchers developed a machine learning algorithm based on convolutional neural networks and near-infrared camera feedback to track the movement of the target tissue during surgery.
Krieger said: "Soft tissue surgery is particularly difficult for robots because its unpredictability forces them to adapt quickly to cope with unexpected obstacles. STAR is a novel control system that adjusts surgical plans in real time like a surgeon. WHAT MAKES STAR special is that it is the first robotic system to autonomously plan, adjust and execute surgical plans in soft tissues with minimal manual intervention during surgery. ”
The suture technique is comparable to that of a surgeon
To test the effectiveness of the operation, the researchers monitored the piglets for 1 week for postoperative survival and performed a limited autopsy. Survival findings suggest that the STAR system can match the performance of specialist surgeons on metrics such as leak-free anastomosis and lumen patency, and the system even exhibits a higher level of consistency.
Figure | In vivo experimental results (A: representative histological example of each anastomotic tissue operated with STAR (n = 4) and manual laparoscopic controlled test (n = 1); B) PMN cells as a proxy for inflammation in each sample; C: representative example of anastomosis collected during autopsy for STAR and control testing. ）
Despite the breakthrough progress of the study, there are still certain limitations in the surgical technique and effectiveness. For example, the successful implementation of robot control algorithms depends on factors such as the accessibility of the target tissue in a certain working area, star robots, manual laparoscopic surgery and remote control of da Vinci surgery are compared on phantom tissue, and in vivo studies can not use da Vinci-based test arms.
The researchers said that in future studies, labelless tissue tracking technology will be integrated and tested, the camera system will be simplified to an endoscope, and tactile sensors will be added, further improving the autonomy of the system and speeding up the time it takes for the robot to complete surgery.
Although the role of manual supervision cannot be eliminated in complex and unpredictable surgical scenarios, the STAR system effectively reduces the surgical risk due to individual differences in the medical experience and ability of doctors, and improves surgical safety and consistency of surgical results.
Krieger said that as the medical field moves toward more laparoscopic surgical methods, it is important to have an automated robotic system designed for such surgeries. "Robotic anastomosis is one way to ensure that every patient can perform surgical tasks that require high precision and repeatability with greater accuracy and precision, regardless of the surgeon's skill." We hypothesize that this will lead to a more predictable and consistent approach to democratizing surgical approaches to patient care. ”
Resources:
https://www.science.org/doi/10.1126/scirobotics.abj2908
https://techxplore.com/news/2022-01-robot-laparoscopic-surgery-human.html