So will robots replace surgeons in the near future? STAR’s inventors see the accomplishment as a proof of concept for now– both for the specific technologies used and for the general concept of “supervised autonomy” in the OR. And when asked, pediatric surgeon Peter Kim, one of the researchers, doesn’t yet feel threatened. “Even though we surgeons take pride in our craft at doing procedures, to have a machine that works with us to improve outcomes and safety would be a tremendous benefit.”
The study concerning STAR has been published in the journal Science Translational Medicine. According to the researchers they programmed their robot to carry out a procedure called intestinalanastomosis, in which a piece of intestine that’s been cut through is stitched back together. the sutures must be tight and regularly spaced to prevent leaks. STAR performed this task both on ex vivo tissue in the lab and on in vivo tissue in an anaesthetised pig, while experienced human surgeons were given the same tasks. When the resulting sutures were compared, STAR’s stitches were more consistent and more resistant to leaks.
Still, the robot didn’t do it all alone. In some 40 percent of its trials, the researchers intervened to offer assistance of some sort, such as holding the thread. But in the other 60 percent of trials, STAR did the job completely on its own. The researchers state these assists do not invalidate their claim of autonomy; instead they see the setup as representative of shared control setups that would be appropriate for real ORs. Human surgeons could supervise procedures or even trade off tasks with the robot, letting the machine do more routine or tedious parts of an operation.
Already some surgical procedures incorporate smart machines. Robots routinely carry out crucial steps in procedures such as orthopedic knee replacements, Lasik eye surgery, and hair transplants. In all these cases the common factor is the fixed nature of the targets. Leg bones, eyes, and heads can be held in place during the procedure. Soft tissue surgeries (like with intestines) are much messier and more difficult to automate, since these slippery pink parts of the body shift around and are hard to track.
The technology used in STAR to help out with these challenges involeved among others a vision system that relied on near infrared fluorescent (NIRF) tags placed in the intestinal tissue; a specialised NIRF camera tracked those markers while a 3D camera recorded images of the entire surgical field. Combining all this data allowed STAR to keep its focus on its target. The robot made its own plan for the suturing job, and it adjusted that plan as tissues moved during the operation. The researchers trained STAR only on how to perform this particular intestinal suturing procedure.