A robotic snake could one day lead to a completely scar-free surgery procedure. Two UK teams are working at developing the first robots that can allow surgeons to perform operations using small incisions.

While the robots aren't the surgical robots that would perform the procedure itself but rather devices that would assist doctors, they could still lead to new techniques in medicine. The concept of scar-free surgery is rooted in a process called natural orifice surgery. Natural Orifice Transluminal Endoscopic Surgery or NOTES is a technique that avoids the large holes used in conventional surgery in favor of using the access points in the body for the procedure. Instead of making a huge incision the surgeon would go in using the mouth, rectum or vagina. The surgeon would then make an incision through the wall of the orifice to reach the target area. NOTES would leave no visible scar and no incision related complications.

While the procedure is promising it can't be done without the aid of robots. Although endoscopes have been modified to allow the removal of some organs, robots are needed to further refine the technique and unlock its potential. Enter the two teams working on robots that can perform for surgeons on NOTES procedures. Both robots carry the surgical tools needed to perform the surgery while doctors can control it from the outside.

One team from the departments of surgery, computing and biomedical engineering at Imperial College London is working on iSnake. The iSnake is a combined robot and imaging device. It is a self-propelled articulated robot about 20-60 cm long. The doctor can tell the robot where to go through its control system and is equipped with imaging sensors.

"iSnake stands for "imaging sensor navigated and kinematically enhanced", said Professor Guang-Hong Yang of the mechatronics laboratory of Imperial College's Hamlyn Centre to the Engineer news site. "We use imaging and sensing so that it can view the tissue its touching and can see where it's going."

OC Robotics is developing a variant to its existing snake-arm robots that can work inside human beings. The company's robot snake-arms have flexible bodies that can work well for inserting into the body but can switch to a stiffer mode so the surgeon can work on the procedure.

"'Pliability is essential to protect the delicate internals of the body upon insertion, but rigidity is required to react to forces at the tip," explained Tim Francois of OC Robotics. "The control we have over the snake-arm also means that we can do 180º bends, enabling us to navigate or reach a range of sites inside the abdominal cavity."

Both robots are in the early stages of development. The iSnake team hopes to be ready for tests in 3 years time. OC Robotics is hopeful that its experience in the field would give the company a head start.